description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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FIELD OF THE INVENTION
This invention relates generally to fluid controls and more particularly relates to a chemically inert fluid control module that may be connected in-line within a chemically corrosive fluid flow circuit that delivers fluids in either a liquid or gaseous state. The fluid control module of the present invention may be utilized to control the flow, pressure or volume of fluid flowing through the fluid flow circuit and is capable of automatically adjusting or “calibrating” the module to compensate for changes in atmospheric pressure or drift in the pressure sensors of the fluid control module.
BACKGROUND OF THE INVENTION
Caustic fluids are frequently used during ultra pure processing of sensitive materials. The susceptibility to contamination of the sensitive materials during the manufacturing process is a significant problem faced by manufacturers. Various manufacturing systems have been designed to reduce the contamination of the sensitive materials by foreign particles and vapors generated during the manufacturing process. The processing of the sensitive materials often involves direct contact with caustic fluids. Hence, it is critical that the caustic fluids are delivered to the processing site in an uncontaminated state and without foreign particulate. Various components of the processing equipment are commonly designed to reduce the amount of particulate generated and to isolate the processing chemicals from contaminating influences.
The processing equipment typically includes liquid transporting systems that carry the caustic chemicals from supply tanks through pumping and regulating stations and through the processing equipment itself. The liquid chemical transport systems, which includes pipes, tubing, monitoring devices, sensing devices, valves, fittings and related devices, are frequently made of plastics resistant to the deteriorating effects of the caustic chemicals. Metals, which are conventionally used in such monitoring devices, cannot reliably stand up to the corrosive environment for long periods of time. Hence, the monitoring and sensing devices must incorporate substitute materials or remain isolated from the caustic fluids.
The processing equipment commonly used in semiconductor manufacturing has one or more monitoring, valving, and sensing devices. These devices are typically connected in a closed loop feedback relationship and are used in monitoring and controlling the equipment. These monitoring and sensing devices must also be designed to eliminate any contamination that might be introduced.
In order to control the flow or pressure within the liquid transporting system, the transporting equipment may utilize information obtained from each of the monitoring, valving and sensing devices. The accuracy of the information obtained from each of the devices may be affected by thermal changes within the system. Further, the inaccuracy of one device may compound the inaccuracy of one of the other devices that depends upon information from the one device. Further, frequent independent calibration may be required to maintain the accuracy of each individual device, however, independent calibration of the devices may prove difficult and time consuming.
Hence, there is a need for a non-contaminating fluid control module which may be positioned in-line within a fluid flow circuit carrying corrosive materials, wherein the module is capable of determining the rate of flow based upon a pressure differential measurement taken in the fluid flow circuit, and wherein the determination of the rate of flow is not adversely affected by thermal changes within the fluid flow circuit, and wherein calibration of the pressure sensors of the fluid control module does not require ancillary or independent calibration of the valve. A need also exists for a fluid control module that avoids the introduction of particulate, unwanted ions, or vapors into the flow circuit. The present invention meets these and other needs that will become apparent from a review of the description of the present invention.
SUMMARY OF THE INVENTION
The present invention provides for a fluid control module that may be coupled in-line to a fluid flow circuit that transports corrosive fluids, where the fluid control module may determine pressure and flow rates and control the pressure, flow or volume within the fluid flow circuit. The rate of flow may be determined from a differential pressure measurement taken within the flow circuit. The fluid control module compensates for changes of temperature within the fluid flow circuit and provides a zeroing feature which compensates for differences in pressure when the fluid is at rest and negates the affects of the valve upon the system. In the preferred embodiment, the components of the fluid control module include a housing having a chemically inert fluid conduit, an adjustable control valve coupled to the conduit, pressure sensors coupled to the conduit, and a constriction disposed within the conduit having a reduced cross-sectional area to thereby restrict flow of fluid within the conduit and allow for reliable flow measurement. The chemically inert housing encloses the control valve and the pressure sensors.
When two pressure sensors are provided, the constriction is positioned between the two pressure sensors within the fluid flow conduit. As described in greater detail below, the fluid control module of the present invention having two pressure sensors provides for bi-directional fluid flow and may be coupled in line to adjacent ancillary equipment. In an alternate preferred embodiment, the fluid control module includes only one pressure sensor, wherein the constriction within the fluid conduit must be positioned downstream of the pressure sensor and valve. Also, the fluid control module having a single pressure sensor must be spaced apart a predetermined distance from ancillary equipment connected in line to the fluid flow circuit.
The drive or actuation of the control valve may be driven either mechanically, electrically or pneumatically by a driver having a known suitable construction and the valving components within the control valve may take on any of several suitable known configurations, including without limitation a poppet, diaphragm, redundant diaphragm, weir valve and/or pinch valve, wherein the components in direct contact with the fluid of the fluid flow circuit are constructed from chemically inert materials.
A controller or integrated circuit may be electrically coupled to the control valve and pressure sensor or sensors. The controller may produce a signal proportional to a fluid flow rate within the fluid conduit and/or a signal proportional to a pressure within the fluid conduit. The controller may control the pressure, rate of flow, or volume such that a desired set point is maintained. The set point may be defined by the user or automatically determined by the controller (for example, during a macro adjustment of the control valve). Further, the controller may adjust the fluid flow rate signal or pressure signal dependant upon changes in atmospheric or fluid pressure. Also, the controller may include a means for macro and micro adjustment of the control valve in response to changes in internal fluid or atmospheric pressure and may re-zero the pressure sensors when flow within the fluid flow circuit stops.
The housing that encloses the control valve and pressure sensors includes a bore extending therethrough, which forms a passage or conduit through which fluids flow, when the housing is connected in-line in a fluid flow circuit. Aligned and sealably connected to the opposed open ends of the bore are pressure fittings. The pressure fittings are constructed from a chemically inert material and are readily available and known to those skilled in the art.
In an embodiment of the present invention the housing has two pressure transducer receiving cavities extending from an external surface thereof, wherein each such cavity communicates independently with the bore. An isolation member may prevent the fluid flow from contacting the pressure transducer receiving cavities. The isolation members may be molded integral with the housing or may be removable. The bore tapers to a constricting region located between the two cavities. The restricted region results in a pressure drop within the bore across points adjacent the two cavities. This change in pressure may be detected by pressure sensor transducers placed within each of the two cavities. The rate of flow may be determined from the drop in pressure. The determination of the rate of flow using the two pressure sensors is described below in greater detail.
A hybrid or fully integrated electronic circuit disposed in the housing is operatively coupled to both pressure sensor transducers and the control valve. The electronic circuit develops a signal that is a measure of the rate of flow within the flow circuit from information sensed by the pressure sensors. Further, the electronic circuit may develop a signal corresponding to one or the other of the downstream or upstream static pressures within the fluid flow circuit, such that the orientation of the flow meter within the flow circuit is interchangeable and the direction of flow may be indicated by comparing the sensed pressure from each pressure sensor. When sensing the static pressures of gases flowing through the flow circuit, a correction may be made to the sensed pressures to correct for non-linearity and flow rates as a result of gas density and compressibility differences and effects.
This electronic circuit may also be used in combination with temperature sensitive components to adjust the pressure measurement associated with each cavity based upon temperature changes within the flow circuit. Further, the electronic circuit or controller may allow for zeroing of the pressure sensors and valve control. The electronic circuit is coupled by electrical leads to an electrical connector and power may be transmitted to the electronic circuit through the electrical leads connected to an external power supply. Further, an analog output such as a standard 4-20 milliamps signal, voltage output, or digital protocol proportional to the calculated rate of flow may be transmitted through additional electrical leads to a display or external controller.
The isolation membrane, pressure sensor, sealing members, spacer ring and hold down ring may be contained within each cavity of the housing. These components and variations thereof are described in greater detail in U.S. Pat. Nos. 5,869,766 and 5,852,244 which are assigned to the same assigns as the present application, the entire disclosure of which is incorporated herein by reference. In a further alternate embodiment, inert sapphire pressure transducers are positioned within respective cavities and in direct contact with the fluid flow, thereby eliminating the isolation membrane.
In use, the fluid control module is coupled in line to a fluid flow circuit. The pressure sensors may be pre-calibrated or the sensors may be calibrated at the time of interconnection with the fluid flow circuit. When calibrating the pressure sensors, the valve may be actuated between an open and closed position. When the pressure sensors indicate that flow has stopped, the output required to actuate the valve may be noted and thereby define an approximation of the closed position of the valve. Various set points may be identified to identify the valve position at various pressures, temperatures and flow rates. The calibration of a single pressure sensor will be described below in greater detail.
Once the flow meter is calibrated, the user may then select whether to control pressure, flow or volume within the fluid flow circuit. If pressure is controlled, the pressure and/or rate of flow is monitored and the valve is accordingly adjusted until a desired set point is reached. If flow is controlled, the pressure and/or flow is monitored and the valve is actuated until the desired set point is reached. The volume of fluid flowing through the fluid conduit may be controlled by monitoring both the pressure and rate of flow and accordingly adjusting the control valve to produce the desired volume of fluid flow. For example, the user may determine that 2 milliliters of fluid is desired. The valve is opened and the pressure and flow rates are monitored, such that it may be determined when 2 milliliters of fluid have passed through the module, wherein the control valve then closes terminating the fluid flow.
When flow is controlled, the controller may store in memory the output of the control valve driver required to obtain a certain flow. In this manner, when the user selects a desired flow, the controller sets the output of the driver approximately equal to an output that previously resulted in the desired flow rate (the macro adjust). Then controller may then manipulate or “fine tune” the control valve to precisely obtain the desired flow rate (the micro adjust). When the flow through the module is terminated by closing the control valve, the controller may then automatically adjust or re-zero the pressure sensors such that the difference between the measured pressures of the two pressure sensors is zero. In this manner, inaccuracy due to thermal changes and sensor drift is avoided. In an alternate preferred embodiment, a second valve is provided, wherein the second valve is a dedicated open/close valve. The output of the controller or electronic circuit may be delivered to an external controller or display.
The advantages of the present invention will become readily apparent to those skilled in the art from a review of the following detailed description of the preferred embodiment especially when considered in conjunction with the claims and accompanying drawings in which like numerals in the several views refer to corresponding parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial sectional side elevational view of the fluid control module of the present invention;
FIG. 2 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention;
FIG. 3 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention having a pneumatic actuated valve;
FIG. 4 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention;
FIG. 5 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention;
FIG. 6 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention;
FIG. 7 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention having a single pressure sensor;
FIG. 8 is a partial sectional side elevational view of an alternate embodiment of the fluid control module of the present invention having a single pressure sensor; and
FIG. 9 is a flowchart showing a sequence the controller may implement to control the fluid control module of the present invention.
DETAILED DESCRIPTION
The present invention represents broadly applicable improvements to chemically inert fluid controls. The embodiments detailed herein are intended to be taken as representative or exemplary of those in which the improvements of the invention may be incorporated and are not intended to be limiting. Referring first to FIG. 1 the fluid control module is generally identified by numeral 10 . The fluid control module 10 generally includes a rectangular housing consisting of a housing body 12 and housing cover 14 , mounting plate 16 , pressure inlet/outlet fittings 18 , pressure transducers 20 and control valve 22 . The housing body 12 and housing cover 14 are preferably manufactured from a chemically-inert, non-contaminating polymer such as polytetrafluoroethylene (PTFE). The cover 14 has bores 24 extending through it for mounting the cover 14 to the housing 12 with appropriate screws. A gasket of known suitable construction is preferably positioned between the cover and housing to allow the cover 14 to be sealed to the housing 12 . Without any limitation intended, a gasket or seal manufactured from a multi-layer fabric, sold under the GOR-TEX trademark by W.L. Gore & Assoc., Inc., allows venting of an internal area of the housing 12 for true atmospheric pressure reference, while restricting the flow of liquids into the internal area of the housing 12 .
A longitudinal bore 28 extends through the housing 12 forming a conduit. Thus, when the fluid control module 10 is connected in-line with a fluid flow circuit, via pressure fittings 18 , the bore 28 serves as the fluid flow passage within the fluid flow circuit. The orientation of the fluid control module 10 , within the fluid flow circuit, may be reversed without affecting its effectiveness. A constricting area 30 is formed in the bore 28 between the two pressure sensors 20 to create a pressure drop as the fluid flow traverses the constricting area or orifice 30 .
In the preferred embodiment, cylindrical cavities 32 extend from an outer surface of the housing 12 to the bore 28 . Those skilled in the art will appreciate that cavities 32 may each extend into the housing from different sidewalls of the housing. The two cavities 32 are separated a predetermined distance by dividing wall 34 . Near the region within the housing where each cavities 32 and bore 28 intersect, an annular lip 36 is formed. Each lip 36 surrounds and further defines the opening to each cavity 32 from the bore 28 . A thin flexible polymer disk or isolation membrane 38 is positioned on the lip 36 of each cavity 32 . Without limitation, the membrane is preferably constructed to have a thickness in a range between 0.001 and 0.040 inches. Preferably, the flexible membrane 38 is manufactured from fluorocarbon polymers. One such tetrafluoroethylene fluorocarbon polymer is sold under the TEFLON trademark by E. I. duPont Nemours. Alternatively, the isolation member 38 may be molded integral with the housing 12 to form a thin wall separating the cavity 32 and bore 28 .
Each pressure transducer 20 is held in place within their respective cavities 32 by spacer ring 48 and externally threaded hold down ring 50 . The isolation membranes 38 and transducers 20 are sealed within the housing 12 by chemically inert o-ring seals 52 . A redundant seal is created by the positioning of o-ring 54 . The seals 52 and 54 are readily available and of known construction to those skilled in the art.
A drain or conduit 40 may be formed extending through the housing 12 into each cavity 32 between the redundant seals 52 and 54 , thereby draining the area between the redundant seals. In this manner, the drain acts as a drainage, passageway or outlet, in the event that fluids leak past seal 52 from the fluid flow circuit. A sensor 42 may be positioned within the drain 40 and electrically connected (by leads not shown) to integrated circuit or controller 46 . Those skilled in the art will appreciate that a conductive sensor, capacitive sensor or non-electric fiber optic sensor may equally be used to sense the presence of fluids in the drain 40 . When fluid leaks past the first seal, the fluid activates the sensor 42 , thereby transmitting a signal to the electric circuit 46 which subsequently sets off a leak indicator. The redundant sealing arrangement helps prevent exposure of the pressure transducer 20 and controller 46 from the potential damaging affects of the caustic fluids. The redundant seal also further isolates the fluid flow, thereby reducing the potential contamination of the fluids.
Each pressure sensor 20 may be of a capacitance type or piezoresistive type known to those skilled in the art. The base of each pressure sensor is in direct contact with the membrane 38 and may be either in pressure contact with or bonded to the membrane by an adhesive, thermal welding or by other known suitable fixation. In an alternate embodiment, an alumina ceramic pressure sensor may be used, wherein the alumina ceramic pressure sensor comprises a thin, generally compliant ceramic sheet having an insulating spacer ring sandwiched between a thicker, non-compliant ceramic sheet. The first thin ceramic sheet or diaphragm is approximately 0.005 to 0.050 inches in thickness with a typical thickness of 0.020 inches. The thicker ceramic sheet has a thickness range between 0.100 to 0.400 inches. The spacer ring may be constructed of a suitable material such as a glass, polymer or alternatively the ceramic sheets may be brazed together. The opposed faces of ceramic disks are metalized by metals such as gold, nickel or chrome to create plates of a capacitor. A similar capacitive pressure transducer is described by Bell et al. in U.S. Pat. 4,177,496 (the '496 patent). Other capacitive pressure transducers similar to that described in the '496 patent are available and known in the art. It is contemplated that the flexible membrane 38 could be eliminated if the pressure sensor used is of the sapphire capacitive pressure transducer type. A sapphire capacitive or sapphire piezoresistive transducer type is inert, and is resistant to wear when subjected to caustic fluids. Having a sapphire sensor in direct communication with the fluid flow may further enhance the pressure measurements of each transducer.
The controller 46 may be in any of several forms including a dedicated state device or a microprocessor with code, and may include Read Only Memory (ROM) for storing programs to be executed by the controller and Random Access Memory (RAM) for storing operands used in carrying out the computations by the controller. The controller 46 is electrically coupled to a power supply and manipulates the electrical circuitry for sensing pressure and controlling the actuation of the control valve, wherein flow, pressure and/or volume may be controlled.
The controller 46 is used to convert the pressure readings from the two pressure transducers 42 and 44 to an analog or digital representation of flow or, alternatively, a pressure reading of the downstream pressure transducer. The raw analog signal from the upstream transducer is supplied to an input terminal and, likewise, the raw analog transducer output signal from the downstream transducer is supplied to an input terminal. The controller 46 computes the instantaneous pressure differences being picked up by the upstream and downstream transducers and performs any necessary zeroing adjustments and scaling.
It is known that, in steady-state flow, the flow rate is the same at any point. The flow rate (I) may be expressed as I m =ρvA. Where ρ represents the density of the fluid, v represents the velocity of the fluid, and A represents the area through which the fluid travels. Using the continuity equation A 1 v 1 =A 2 v 2 , the rate of flow within the fluid control module 10 may be found equal to a constant multiplied by {square root over (P 1 −P 2 )}. The controller 46 thus computes the pressure and rate of flow from the data received from the two pressure sensors. Those skilled in the art will recognize that with laminar flow, the rate of flow approximates more closely a constant multiplied by P 1 −P 2 . Hence, a low flow limit could be built into the system, such that if the “Reynolds number” is below a certain threshold, the flow meter identifies the flow rate as zero. The controller 46 may then convert the computed rate of flow into a digital signal or an analog signal falling in the range of from 4 mA to 20 mA for use by existing control systems.
As fluid flows through the flow circuit, the pressure adjacent each of the two cavities is detected by the controller 46 , whereby the rate of flow may be calculated from the two detected pressures. The gauge pressure or absolute pressure may equally be used. Those skilled in the art will recognize that the flow rate may be calibrated so that minimum desired output values are associated with minimum pressure and maximum desired output pressures are associated with maximum pressure. For example, a pressure sensor intended to measure 0 to 100 psig (pounds per square inch gauge) can be calibrated to read 4 mA (milliamps) at 0 psig and 20 mA at 100 psig.
The conduit 28 interconnects with the control valve 22 , wherein a valve seat 60 is formed within the fluid conduit. A double diaphragm 62 is actuated fore and aft, wherein when the diaphragm is actuated into engagement with the valve seat 60 , fluid flow past the valve seat is terminated. Alternatively, a single diaphragm may be utilized to control the flow of fluid past the valve seat 60 (see FIG. 2 ). Those skilled in the art will appreciate that the double diaphragm 62 is unaffected by changes in atmospheric pressure. The driver 66 shown in FIG. 1 used to actuate the diaphragm 62 is of the electric motor type. Those skilled in the art will appreciate that the actuation of the valve between the open and closed position may be accomplished with any of several mechanical electrical or pneumatic drivers of known suitable construction. Further, without limitation, the mechanism for opening and closing flow may comprise for example, a diaphragm, poppet, weir valve, or pinch valve with the diaphragm and valve seat being preferred.
FIG. 3 illustrates an alternate embodiment of the driver 66 being of the pneumatic type. A piston 68 is sealed within a sealed chamber 70 , wherein the mechanical force of a compression spring 72 forces the piston 68 in a downward or first direction and a pressurized air line 74 increases the pressure on the lower end 76 of the piston to force the piston 68 upward thereby compressing the spring 72 . In this manner, the air pressure within the chamber 70 may be increased or decreased a controlled amount to actuate the piston 68 and thus the diaphragm 64 attached to the piston 68 between an open and closed position. The lower end of the diaphragm 64 may include a conical member 78 extending therefrom which may enhance the sealing between the valve seat 60 and the diaphragm 64 (see FIG. 4 ). Alternatively, a valve stem 80 extending from the piston 68 may extend through the chamber wall 82 through a bore 82 having a seal 84 to seal the air chamber 70 and provide for fore and aft motion of the valve stem 80 within the bore 82 (see FIG. 5 ). The lower end 86 of the valve stem 80 seals directly with the valve seat 60 when in the closed position. The lower end 86 may be tapered to further enhance the sealing between the valve stem 80 and the valve seat 60 when in the closed position (see FIG. 6 ).
Referring to FIGS. 7 and 8 alternate embodiments of the fluid control module 10 are shown having a single pressure sensor for determining flow rates within the fluid flow conduit. The control valve 22 shown in FIG. 7 is pneumatically driven as described above in greater detail. The control valve 22 shown in FIG. 8 is actuated by the motor 66 as described above in greater detail. When determining flow rates with the fluid control module of the type shown in FIGS. 7 and 8, the orifice 30 must be downstream of the pressure sensor 20 and control valve 22 and the output end 90 of the fluid control module 10 must be connected to a conduit, tubing, void, or other pathway wherein the pressure therein is at atmospheric pressure (a known constant). In this manner the flow rate may be determined as described above, wherein the pressure P on the downstream side of the orifice is a constant. Additionally, a tubing of known length and diameter may be coupled to the output end 90 of the fluid control module 10 , whereby the pressure difference between the pressure at the output end 90 and the pressure within the tubing is constant. In use, the tubing may be filled with fluid and then the control valve 22 may be shut. The pressure sensor is then calibrated to indicate zero pressure. When the control valve is opened, then the pressure sensor will indicate the change in pressure.
Having described the constructional features of the present invention the mode of use in conjunction with FIG. 9 will next be described. The controller 46 either automatically or when prompted by the user calibrates the pressure sensors 20 and control valve 22 (see block 100 ). During the calibration process, the controller creates and stores in memory values corresponding to valve position, flow rate and internal and external pressure for predetermined set points. Once the valve position, flow and pressure are known for desired set points, the controller may automatically set the valve position based on determined flow pressure or demand by the external process. Alternatively, the user may select a desired set point and the controller adjusts the valve position based on measured pressure and flow rates (see block 102 ). The controller then determines whether it is desired to control pressure (see decision block 104 ). If pressure is to be controlled, the controller monitors the pressure and/or flow rate and adjusts the valve to keep the pressure at a controlled amount (see block 106 ). If it is not desired to control pressure, the controller then determines whether it is desired to control flow (see decision block 108 ). If flow is to be controlled, the controller monitors pressure and/or flow and adjusts the valve to keep the flow rate at a controlled amount (see block 110 ).
The control may include a macro and micro adjust of the control valve, wherein the controller stores values associated with flow rate, pressure, temperature and valve position for the set points. When the flow, for example, is controlled the controller adjusts the valve to roughly approximate the valve position for prior measured pressure temperature and valve position for the desired flow (the macro adjust). Thus, the flow rate may be approximated rather quickly and then the control may make minor adjustments to the valve position to obtain an even more precise control of flow (see block 112 ). If volume is to be controlled (see decision block 114 ) then the flow rate and pressure are monitored and the valve is opened for a time sufficient to allow the controlled volume of fluid to pass past the control valve 22 (see block 116 ). If neither the pressure, flow or volume is to be controlled then the controller waits to receive input (see loop 118 and block 102 ).
During fluid processing, the controller 46 may automatically re-zero or calibrate the pressure sensors when the control valve 22 is closed (see block 120 ). Alternatively, a second dedicated valve may be provided which is operable in either an open or closed position. The controller may be programmed to re-zero the pressure sensors when the second dedicated valve is in the closed position. During processing, the pressure within the flow conduit may undergo significant changes, thereby requiring changes in the valve position to keep the flow rate, for example, constant (see block 122 ). The controller 46 waits to receive the next input (see loop 124 and block 102 ). Thus, the control module of the present invention eliminates the additional components and disadvantages of interconnecting individual pressure sensors and individual control valves.
This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself. | A fluid control module that may be connected in-line within a chemically corrosive or ultra pure fluid flow circuit that delivers fluids in either a liquid or gaseous state. The fluid control module of the present invention may be utilized to control the flow, pressure or volume of fluid flowing through the fluid flow circuit and is capable of automatically adjusting or “calibrating” the module to compensate for changes in atmospheric pressure or drift in the pressure sensors of the fluid control module. The fluid control module also includes a rapid or macro adjustment of the control valve to reach the desired flow rate at a quicker pace. | 8 |
This application is a continuation of application Ser. No. 552,439, filed July, 13, 1990, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to web processing apparatus and, more particularly, to a speed control assembly for a web winder.
continuous web processing apparatus such as web printers generally include a web "unwind" or "supply" spool from which unprocessed web material is supplied and a web "rewind" or "windup" or "collection" spool upon which the processed web is collected. Each of these spools is typically mounted upon a separate, driven, winder apparatus which rotates the spool mounted thereon at a selected rate. As the diameter of the web wound about a spool changes, the rotational velocity of the spool must also change if a constant web supply or collection rate is to be maintained. The rotation rate of the web winding apparatus must also be adjusted to accommodate for speed fluctuations at various web processing operating stations which are positioned along the web between the unwind and rewind spools. The most common method for maintaining proper winder speed is through use of a dancer assembly. A dancer assembly is a device consisting of at least one idler roll which is positioned in contact with the web of material. The dancer roll is displaceable in a direction transverse to the direction of web movement and is biased in a direction which opposes the tension applied to the dancer roll by the web. The bias force is of a magnitude such that when the web processing machine is operating at its normal web tensions, the dancer is positioned near the center of its range of movement. If the speed of the web varies with respect to the speed of the associated winder in a manner which decreases web tension, the dancer is displaced by the bias force in a direction to take up the resulting "slack" in the web. If the operation of the associated winder with respect to web line speed is such that the tension in the web increases, the dancer is displaced by the web tension force in a direction which shortens the web path and reduces web tension.
Winder speed is controlled by varying the speed of the winder in response to the displacement of the associated dancer assembly.
Various methods of processing a dancer displacement signal to control winder speed are known in the prior art. One method, known as 100% proportional control, is illustrated in FIG. 1. In this method of control, the winder motor velocity is increased or decreased as a linear function of dancer displacement from a dancer position near one end of the dancer travel path. The winder velocity to dancer position relationship for a supply winder is indicated in solid lines. The winder velocity to dancer position relationship for a collection winder having a dancer assembly identical to that for the supply winder is indicated in dashed lines. In such a system, at one end of the dancer travel range the winder operates at full speed, and at the other end of the dancer travel range the winder stops. Typically, the range of dancer displacement is selected to be somewhat larger than the range of dancer displacement needed to compensate for changes in roll diameter in order to accommodate other transient fluctuations in web speed. Such 100% proportional speed control results in a system which is very responsive but difficult to stabilize. In situations where the web being processed is an extensible web such as plastic film, a 100% proportional control system becomes totally unstable and unusable.
In a variation of the 100% proportional control method illustrated in FIG. 1, the dancer displacement signal is used in the same manner to control web speed. However, it accounts for only a small portion, e.g. 10%, of the total winder velocity control signal. The remainder of the signal is a line speed reference signal produced by a web speed monitor positioned along the web at a point intermediate the unwind and rewind assemblies. In such a control scheme, the dancer is relatively unresponsive and thus the system is easy to stabilize for stead-state conditions. However, in such a scheme, the dancer typically runs off-center some amount to compensate for calibration error or web stretch. This type of system experiences trouble with major tension variations in the web and will reach a mechanical limit for correction due to the dancer's lack of responsiveness.
In another method of winder speed control, the winder is provided with a tachometer which provides a speed signal. This winder speed signal and a web line speed signal are provided to a computer and used to compute the associated winder spool web diameter. A base winder speed is then calculated by dividing line speed by winder spool web diameter. The calculated winder speed is thereafter trimmed with a velocity signal calculated as a linear function of dancer displacement such as illustrated in FIG. 1. Such systems are quite expensive and require factory technicians for accurate calibration and setup.
Another method of winder speed control is known in the art as 100% integrated dancer centering speed control. According to this method, an analog integrator receives an input representative of linear dancer displacement and a winder acceleration (as opposed to velocity) signal is calculated which is linearly proportional to the dancer displacement signal. In such a system, the dancer under normal operating conditions remains at the center of its displacement range. However, it is generally difficult to find a balance between stability and responsiveness for such a control system. A graph indicative of winder motor acceleration response to dancer displacement for such a system is illustrated in FIG. 2.
In a variation on the 100% integrated dancer centering control system illustrated in FIG. 2, a signal identical to that illustrated in FIG. 2 is initially provided. However, the control system rather than using this signal as a motor acceleration signal instead uses it as a spool diameter signal and the winder velocity signal is provided by dividing web line speed by this diameter signal. Such systems generally require a factory technical for setup. Such systems are subject to failure due to calibration shifts and also experience stability problems.
SUMMARY OF THE INVENTION
The present invention may comprise a speed control assembly for a rotatable web winding apparatus comprising: dancer means engaged with a web of material wound about said winder apparatus for displaceably responding within a predetermined range of dancer positions to tension variations in said web; first control signal generating means for generating a first control signal in response to dancer means displacement from a predetermined centered position, the ratio of dancer displacement to said first control signal being variable over said range of dancer displacement positions; and dancer response rotation control means for rotationally accelerating said winding apparatus in response to said first control signal.
The invention may also comprise a speed control assembly for a rotatable web winding apparatus comprising dancer means engaging with a web of material wound about said winder apparatus for displaceably responding within a predetermined range of dancer positions to tension variations in said web; first control signal generating means for generating a first control signal in response to dancer means displacement from a predetermined centered position, the ratio of dancer displacement to said first control signal being variable over said range of dancer displacement positions; dancer response rotation control means for rotationally accelerating said winding apparatus in response to said first control signal; wherein said dancer means comprises a dancer signal generating means for generating a dancer signal which is proportionate to the amount of displacement of said dancer means from said predetermined centered position and wherein said first control signal generating means processes said dancer signal to generate said first control signal; wherein said first control signal changes relatively slowly in response to dancer displacement within a first range of dancer positions which includes said predetermined centered position and wherein said first control signal changes relatively more rapidly in response to dancer displacement within a second range of dancer positions lying outside of said first range of positions; wherein said first control signal changes relatively most quickly in response to dancer displacement in a third range of dancer positions lying outside of said second range of positions; wherein the ratio of said first control signal to said dancer signal is a first constant value when said dancer mean is positioned within said first range of dancer positions; wherein the ratio of said first control signal to said dancer signal is a second constant value greater than said first constant value when said dancer means is positioned within said second range of dancer positions; wherein the ratio of said first control signal to said dancer signal is a third constant value greater than said second constant value when said dancer means is positioned within said third range of dancer positions; wherein said dancer response rotation control means comprises: motor means drivingly linked to said winding apparatus for rotating said winding apparatus; motor control means for controlling the speed of said motor means in response to a motor speed control signal; and speed control signal generating for receiving said first control signal and for generating said motor speed control signal in response thereto; web speed monitoring means for measuring web speed at a position on the web which is more remote from said web winding apparatus than the position of said dancer means and for generating a web speed signal indicative of said measurement; web speed response rotation control mean for receiving said web speed signal and for rotationally accelerating said winding apparatus by an amount dependent upon said web speed signal; whereby total winding apparatus acceleration is dependent upon web tension at said dancer means and web speed at said web speed monitoring means.
The invention may also comprise a method of controlling the rotational speed of a web winding apparatus comprising: monitoring the displacement of a web dancer from a predetermined dancer position; generating a first control signal which is a predetermined nonlinear function of dancer displacement over a predetermined range of dancer displacement position; accelerating said web winding apparatus in response to said first control signal.
BRIEF DESCRIPTION OF THE DRAWINGS
An illustrative and presently preferred embodiment of the invention is shown in the accompanying drawings in which:
FIG. 1 is a graph illustrating the relationship between dancer position and winder motor velocity in one prior art method of winder control.
FIG. 2 is a graph illustrating the relationship between dancer position and winder motor acceleration in a second prior art method of web winder control.
FIG. 3 is a schematic elevation view of a web processing system.
FIG. 4 is a graph illustrating the relationship between dancer position and winder motor acceleration for web winders used in the web processing assembly of FIG. 3.
FIG. 5 is a circuit diagram of a circuit used for generating a web winder motor velocity signal from a dancer displacement signal.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 is a schematic illustration of a web processing apparatus 10 such as a web printer. A continuous web of material 12 is unwound from a supply roll 14 (also referred to as an unwind spool), processed at one or more processing stations 16 located downstream from the supply roll 14, and collected on a web rewind spool 18 (also referred to as a collection spool or a windup spool).
The unwind spool 14 is rotated about an axis AA by a direct current (DC) drive motor 22 which rotates spool 14 at a rotation rate which is directly proportional to the drive motor rotation rate. The drive motor 22 operates at a velocity which is directly proportional to a velocity command signal 24 which it receives from speed control assembly 26.
Speed control assembly 26 generates velocity control signal 24 by integrating a motor acceleration signal 28 which it receives from nonlinear dancer response circuit 30.
Nonlinear dancer response circuit 30 calculates control signal 28 from a dancer signal 32 generated by dancer displacement sensing device 34. Dancer signal 32 is directly proportional to the displacement of dancer 36.
Dancer 36 includes an idler roll 38, engaged by web 12, which is displaceable between a lowermost position 40 and an uppermost position 42. The dancer roll is biased toward position 40 by a conventional biasing device (not shown) of the type adapted to provide a biasing force which is constant over the displacement of the dancer from position 40 to 42. The biasing force is selected which corresponds to the normal tension setting of the web processing apparatus. Thus, if web velocity downstream of dancer assembly 36 becomes greater than the surface velocity of the web on spool 14, dancer roll 38 is displaced downwardly, and if web downstream velocity falls below that of the surface velocity of the web on spool 14, dancer 38 is displaced upwardly.
Web processing stations illustrated generally at 16 may comprise a pair of nip rolls 50, 52, which are driven at a relatively constant rate by a nip motor 54. In a typical processing operation, continuous web 12 is provided with a repeating set of web graphics at a printing nip 56 provided by rolls 50, 52.
Downstream of the web processing station 16, rewind spool 18 collects the processed web. Rewind spool 18 is rotated about axis BB by a DC drive motor 62 which drives spool 18 at a rate proportional to the drive motor rotation rate. Drive motor 62 rotates spool 18 at a rate which is linear proportionate to its own rotation rate. DC motor 62 receives a speed control command 64 from a control circuit 66 which integrates an acceleration command 68 which is generated by nonlinear dancer response circuit 70. Dancer response circuit 70 receives a dancer displacement command 72 from a dancer displacement signal generating device 74 which generates a signal that is linearly proportionate to the displacement of dancer 76. Dancer 76 comprises an idler roll 78 which is displaceable between positions 80, 82 and which as a centered position 84. Dancers 36, 76 may be of identical construction and may be of a type which are commercially available and well-known in the art such as, for example, Model No. L10075966 of Winder Assembly Model 192, Se. No. 27087-02 manufactured by Gloucester Engineering Company having a business mailing address of P.O. Box 900, Gloucester, Mass. 01930. Dancer displacement signal generating means 34, 74 may also be of a type well-known in the art such as those sold as a unit with the above-referenced commercially available dancers.
A graph showing the value of signal 28 and 68 as the vertical axis and showing the relative dancer displacement from a center position as the horizontal axis in a typical dancer winder configuration is illustrated in FIG. 4. The graph of signal 68 is indicated in solid lines, and the graph of signal 28 is illustrated in dashed lines. As shown by FIG. 4, motor acceleration signal 68 comprises a relatively flat response in a central portion 82 of the dancer range of motion, a relatively larger response in an intermediate portion 84, and a relatively highest response in an exterior portion 86. In the illustrated embodiment, in the central region 82 of dancer motion acceleration signal 68 comprises a straight line 82A. In intermediate region 84, signal 68 may comprise straight lines 84A, 84B of the same or slightly different slope steeper than the slope of 82A. In the exterior response region 86, signal 68 may also comprises two straight lines 86A, 86B of the same of slightly different slope steeper than the slopes of 84A of 84B. A response characteristic such as that illustrated in FIG. 4 provides a system which is extremely stable and yet also capable of providing relatively high-rate response when necessary.
The circuitry used to produce motor acceleration signal 68 is illustrated in FIG. 5. The circuit comprises a first resistance pot P 1 which may be a 1 MΩ-resistance pot; a second resistance pot P 2 which may be a 100 Ω-resistance pot; and a third resistance pot P 3 which may be a 10 kΩ-resistance pot. The circuit may also comprise a first diode pair D 3 , D 4 , a second diode pair D 5 , D 6 , a third diode pair D 7 , D 8 , and a fourth diode pair D 9 , D 10 . In one exemplary embodiment, the first diode in each diode pair is a zener diode which conducts at 2 volts, and the second diode in each diode pair is a rectifier diode which conducts at 1/2 volt and the linear dancer input voltage is equal to the dancer displacement from a centered position as measured in inches, e.g. a dancer displacement of +7.5 inches from a centered position produces a dancer signal 70 voltage of +7.5 volts, and a dancer displacement of -2.5 inches from center produces a dancer signal voltage of -2.5 volts. In this arrangement, the value "A" of signal 68 produced by the nonlinear dancer response circuitry 70 may be represented by the algorithms
A=x/p.sub.1, for -2.5<x<+2.5;
A=x/p.sub.1 +(x-2.5)/p.sub.2, for -7.5<x<-2.5<x<7.5;
and
A=x/p.sub.1 +(x-2.5)/p.sub.2 +(x-7.5)/P.sub.3, for -10<x<-7.5 and 7.5<x<10
where x is the dancer displacement in inches from a centered position and where p 1 , p 2 , and p 3 are the resistance in ohms of resistance pots p 1 , p 2 , and p 3 , respectively.
The signal 68 produced by nonlinear dancer response circuitry 70 is thereafter integrated with respect to time by integrator circuit 66. Integrator circuit 66 comprises a zenor diode D 11 which in the exemplary embodiment conducts current at a voltage value about 10 volts. The circuit further comprises a resistor pot P 4 which may have a resistance of 100 KΩ, a capacitor C 1 which may have a capacitance of 10 μfd, and an operational amplifier OA 1 which may be a general purpose op amp such as the LM741C, produced by National Semiconductor Corp., 2900 Semiconductor Drive, Santa Clara, Calif. This circuit integrates signal 68 over time producing integrated signal 64 which is the velocity command signal to DC motor 62, i.e. DC motor 62 responds to signal 64 by operating at a velocity which is directly proportional to signal 64. Although DC drive motor 62 takes a short period of time to accelerate, the power of the motor is such that the motor response with respect to the speed signal may be considered to be instantaneous. In one preferred embodiment of the invention, the DC motor 62 comprises a model 40 hp, 289 AT2 frame 1750 rpm, manufactured by Emerson Electric Company having a business address of 3036 Alt Boulevard, Grand Island, N.Y., 14072. The typical range of speed control of such a motor over a range of 500 volts is between 0 and 1750 rpm. The construction of nonlinear dancer response circuitry 30 and integrator circuit 26 may be identical to that shown at 70 and 66, respectively, in FIG. 5 with the difference that the linear dancer input signal is inverted by a signal inverter (not shown) prior to being received by nonlinear dancer response circuitry 30 or, alternatively, the signal output 24 of the integrator circuitry 26 may be inverted prior to being applied as a velocity command signal to drive motor 22.
In an alternative embodiment of the invention as illustrated in phantom in FIG. 3, a web speed monitoring device 90 monitors web speed at a position downstream from dancer 36 and generates a web speed voltage signal 92 which is linearly proportionate to web speed. Web speed signal 92 is provided as an input to a divider chip 94 which also receives signal 24 as an input thereto. The divider chip 94 divides the speed signal 92 by signal 24. Signal 24 is proportionate to the web diameter which is wound about spool 14.
While an illustrative and presently preferred embodiment of the invention has been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art. | A speed control assembly for a rotatable web winding apparatus comprising a dancer engaged with a web of material wound about the winder apparatus for displaceably responding within a predetermined range of dancer positions to tension variations in the web; a first control signal generating device for generating a first control signal in response to dancer displacement from a predetermined centered position, the ratio of dancer displacement to the first control signal being variable over the range of dancer displacement positions; and a dancer response rotation control device for rotationally accelerating the winding apparatus in response to the first control signal. | 1 |
FIELD OF THE INVENTION
[0001] The invention relates generally to plasma processing, and more particularly, to a plasma processing apparatus for selectively removing extraneous material from a substrate.
BACKGROUND OF THE INVENTION
[0002] Plasma processing systems are routinely used to modify the surface properties of substrates used in applications relating to integrated circuits, electronic packages, and printed circuit boards. In particular, plasma processing systems are used to treat surfaces in electronics packaging, for example, to increase surface activation and/or surface cleanliness for eliminating delamination and bond failures, improving wire bond strength, ensuring void free underfilling of chips on circuit boards, removing oxides, enhancing die attach, and improving adhesion for die encapsulation. Typically, substrates are placed in the plasma processing system and at least one surface of each substrate is exposed to the plasma. The substrate's outermost atomic layers may be removed from the surface by physical sputtering, chemically-assisted sputtering, chemical reactions promoted by reactive plasma species, and combinations of these mechanisms. The physical or chemical action may also be used to condition the surface to improve properties such as adhesion or to clean undesired contaminants from the substrate surface.
[0003] During semiconductor manufacture, semiconductor die are commonly electrically coupled by wire bonds with leads on a metal carrier, such as a lead frame. Lead frames generally include a number of pads each having exposed leads used to electrically couple a single semiconductor die with a circuit board. One semiconductor die is attached to each pad and external electrical contacts of the die are wire bonded with nearby portions of the leads. Each semiconductor die and its wire bonds are encapsulated inside a package consisting of a molded polymer body designed to protect the semiconductor die and wire bonds from the adverse environment encountered during handling, storage and manufacturing processes as well as to dissipate the heat generated from the semiconductor die during operation. The molded packages project as three-dimensional features from one side of the otherwise generally-planar lead frame
[0004] During the molding process, the lead frame and the multiple attached semiconductor die are positioned between two mold halves. One mold half includes numerous concavities each receiving one of the semiconductor die and mimicking the shape and arrangement of the packages. The mold halves are pressed together in an attempt to seal the entrance mouths to the concavities. The molding material, which is injected into the mold, fills the open space inside the concavities for encapsulating the semiconductor die and wire bonds. However, molding material can seep out of the concavities and flow between the mold halves to form thin layers or flash on the exposed portions of the leads. This thin flash has a thickness typically less than about 10 microns. Flash affects the ability to establish high quality electrical connections with the exposed portions of the leads and, hence, with the encapsulated semiconductor die.
[0005] Various conventional approaches have been developed for alleviating the effects of flash. Flash may be prevented by covering the backside of the lead frame with tape during the molding process. However, adhesive may be transferred from the tape to the lead frame backside and remain as a residue after the tape is removed. In addition, tapes suitable for this application are relatively expensive, which needlessly contributes to the cost of manufacture. Flash may be removed after molding by mechanical and chemical techniques, or with a laser. These removal approaches also suffer from restrictions on their use. For example, the lead frame is susceptible to damage from mechanical flash removal techniques, such as chemical mechanical polishing. Chemical processes may be ineffective unless highly corrosive chemicals are used, which potentially raises issues of worker safety and waste disposal of the spent corrosive chemicals. Laser removal is expensive due to the equipment costs and leaves a residual carbon residue behind on the lead frame.
[0006] There is thus a need for a plasma processing system that can efficiently and effectively remove extraneous amounts of material, such as excess molding material, from an area on a substrate while shielding other areas on the substrate from the plasma.
SUMMARY OF THE INVENTION
[0007] The present invention addresses these and other problems associated with removing extraneous material from an area on a substrate with a plasma without exposing features on other areas on the substrate to the plasma. To that end, the present invention provides a shielding assembly for holding a substrate during treatment with a plasma. The substrate has a first area, a feature projecting from the first area, and a second area covered by an extraneous material. The shielding assembly comprises a first member including a concavity positioned and dimensioned to receive the feature and to shield the feature from the plasma and a second member including a window for passing the plasma into contact with the extraneous material for removing the extraneous material from the second area with the plasma.
[0008] One situation in which the shielding assembly of the present invention is particularly beneficial is in removing flash from a lead frame without exposing the molded packages, that project from the otherwise generally-planar lead frame, to the plasma. The semiconductor die inside the semiconductor packages are sensitive to plasma exposure and, therefore, it is desirable to shield the package from the plasma during a plasma deflashing process.
[0009] The shielding assembly may be a component of a processing system further including a vacuum chamber enclosing a processing space capable of being evacuated to a partial vacuum, an electrode positioned in the processing space, and a gas port defined in the vacuum chamber for admitting a process gas into the processing space. The system further includes a power supply electrically coupled with the electrode, the power supply operative for converting the process gas to the plasma. The fixture is positioned in the processing space at a location appropriate for plasma treatment.
[0010] In another aspect of the invention, a method is provided for plasma treating a substrate having a first area, a feature projecting from the first area, and a second area covered by an extraneous material. The method comprises placing the substrate in a processing space of a vacuum chamber and generating a plasma in the processing space. The first area of the substrate is covered with a shielding assembly having a concavity configured to receive and shield the feature from the plasma. The second area is exposed to reactive species from the plasma effective for removing the extraneous material.
[0011] These and other objects and advantages of the present invention shall become more apparent from the accompanying drawings and description thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.
[0013] FIG. 1 is a diagrammatic view of a plasma treatment system for plasma treating substrates in accordance with the principles of the present invention;
[0014] FIG. 2 is an exploded view of a shielding assembly for use with the plasma treatment system of FIG. 1 ;
[0015] FIG. 3 is a perspective view of the assembled shielding assembly of FIG. 2 ;
[0016] FIG. 4 is a perspective view of the mask of FIG. 2 illustrating the loading of the substrate into the mask; and
[0017] FIG. 5 is a detailed view in partial cross-section of a portion of FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] With reference to the FIG. 1 , a plasma treatment system 10 includes a treatment chamber 12 constituted by walls that enclose a processing space 14 . During a plasma process, the treatment chamber 12 is sealed fluid-tight from the surrounding ambient environment, evacuated to a suitable partial vacuum, and supplied with a process gas appropriate for the intended plasma treatment. A vacuum pump 16 is used to evacuate the processing space 14 of treatment chamber 12 through a valved vacuum port 17 . Vacuum pump 16 may comprise one or more vacuum pumping devices with controllable pumping speeds as recognized by persons of ordinary skill in the art of vacuum technology.
[0019] Process gas is admitted at a regulated flow rate to the processing space 14 from a process gas source 18 through an inlet gas port 21 defined in the treatment chamber 12 . The flow of process gas from the process gas source 18 to the processing space 14 is typically metered by a mass flow controller (not shown). The gas flow rate from the process gas source 18 and the pumping rate of vacuum pump 16 are adjusted, as needed, to create a processing pressure and environment suitable for plasma generation and suitable for the intended treatment process. Processing space 14 is continuously evacuated simultaneously as process gas is introduced from the process gas source 18 so that fresh gases are continuously exchanged within the processing space 14 when the plasma is present, and any spent process gas and volatile species removed from a substrate 20 are eliminated from the processing space 14 .
[0020] A power supply 22 is electrically coupled with, and transfers electrical power to, an electrode 24 inside of the treatment chamber 12 . Power transferred from the power supply 22 is effective for forming a plasma 26 from the process gas confined within processing space 14 and also controls the direct current (DC) self-bias. Although the invention is not so limited, the power supply 22 may be a radio-frequency (RF) power supply operating at a frequency between about 40 kHz and about 13.56 MHz, preferably about 13.56 MHz, although other frequencies may be used, and a power level, for example, between about 4000 watts and about 8000 watts at 40 kHz or 300 watts to 2500 watts at 13.56 MHz. Those of ordinary skill in the art will appreciate that different treatment chamber designs may permit different bias powers. A controller (not shown) is coupled to the various components of the plasma treatment system 10 to facilitate control of the etch process.
[0021] Plasma treatment system 10 may assume different configurations understood by those of ordinary skill in the art and, therefore, is not limited to the exemplary configuration described herein. For example, the plasma 26 may be generated remote of treatment chamber 12 and delivered to the processing space 14 . Plasma treatment system 10 is further understood to include components not shown in FIG. 1 that are necessary for operation of system 10 , such as a gate valve disposed between the processing space 14 and the vacuum pump 16 .
[0022] A shield or shielding assembly 30 holds one or more substrates 20 ( FIG. 2 ) in the exemplary treatment system 10 at a position in the processing space 14 of treatment chamber 12 suitable for performing the plasma treatment. Three-dimensional features 28 that project from one side 20 a of the substrate 20 and the opposite side 20 b of substrate 20 may be approximately planar. The three-dimensional features 28 are to be protected during the plasma treatment and, accordingly, are to be shielded from the plasma 26 during plasma treatment of substrate 20 . The invention contemplates that shielding assembly 30 may hold a single substrate 20 for plasma treatment.
[0023] With reference to FIGS. 24 , the shielding assembly 30 includes a plurality of first members or masks 34 , a second member or upper frame 36 , and a third member or lower plate 32 that may rest on the powered electrode 24 . Each of the masks 34 is adapted to mask side 20 b of a corresponding one of substrates 20 so that the three-dimensional features 28 are shielded from the plasma in processing space 14 . The upper frame 36 secures the substrates 20 and masks 34 with the lower plate 32 .
[0024] The lower plate 32 includes a projecting annular rim 38 and parallel, equally spaced ribs 40 each of which extends between opposite sides of the rim 38 . The rim 38 and ribs 40 cooperate to define recesses 42 below a plane defined by the rim 38 . Each recess 42 is dimensioned with a length, width, and depth appropriate to receive a single mask 34 . After the masks 34 are positioned in the recesses 42 and the substrates 20 are positioned in the shielding assembly 30 , an annular peripheral portion 44 of the upper frame 36 may physically contact the rim 38 of lower plate 32 for establishing good electrical and thermal contact. The ribs 40 are generally positioned between adjacent masks 34 . The lower plate 32 may be attached to the electrode 24 or, alternatively, may otherwise be positioned in the processing space 14 at a location suitable for plasma processing.
[0025] Each mask 34 is constructed with multiple concavities 46 each of which is correlated with the three-dimensional features 28 carried on side 20 b of one or more substrates 20 . Generally, the concavities 46 are arranged, dimensioned and positioned as the reverse image or complement of three-dimensional features 28 projecting from side 20 b. The depth of the concavities 46 is preferably adjusted so that the rim 38 of lower plate 32 contacts the peripheral portion 44 of upper frame 36 .
[0026] Each mask 34 is oriented spatially with the concavities 46 facing away from the powered electrode 24 . One or more substrates 20 are positioned inside each of mask 34 with the concavities 46 and three-dimensional features 28 coincident and registered. As a result, an exposed upper surface 20 b of each substrate 20 faces away from the powered electrode 24 and the substrates 20 are oriented such that the three-dimensional features 28 face toward the powered electrode 24 .
[0027] Each of the concavities 46 has dimensions (length, width, and depth) with sufficient clearance to receive one of the three-dimensional features 28 . The concavities 46 may be dimensioned equally or have individual dimensions tailored to accommodate three-dimensional features 28 of differing dimensions across the substrate 20 . As a result, each of the concavities 46 defines a seal with the substrate 20 about the perimeter of each three-dimensional feature 28 adequate to prevent the ingress of the plasma 26 . The invention contemplates that a single mask 34 may be sufficient to shield the substrates 20 and/or that a single concavity 46 may be effective for shielding the three-dimensional features 28 from the plasma 26 . For example, a single mask 34 having a single concavity 46 extending about the periphery of the mask 34 may be effective for shielding the lower surface 20 a of the substrates 20 from the reactive species in the plasma 26 .
[0028] With continued reference to FIGS. 2-4 , the upper frame 36 is positioned on the substrates 20 held by the masks 34 . The mass of the upper frame 36 applies a downward force that secures the substrates 20 and masks 34 with the lower plate 32 . The upper frame 36 includes equidistant parallel ribs 48 extending between two opposite sides of the generally rectangular opening defined inside the annular peripheral portion 44 , which divide this space inside the peripheral portion 44 into a plurality of windows 50 . When the shielding assembly 30 is assembled, the ribs 48 are generally positioned between adjacent substrates 20 . Cross members 52 function to strengthen the upper frame 36 and only cover portions of the substrates 20 for which plasma treatment is not required or desired. The specific location of the cross members 52 will depend upon the arrangement of the three-dimensional features 28 on substrate 20 and will operate to divide the windows 50 into even smaller windows. The present invention contemplates that the upper frame 36 may be constructed to deliberately shield areas of the upper surface 20 b of the substrate 20 from the plasma. Key pins 54 in the diagonal corners of the upper frame 36 are registered with corresponding key bores 56 in the lower plate 32 , of which only one key bore 56 is visible in FIG. 2 , to ensure registration between these components during assembly of the shielding assembly 30 .
[0029] The lower plate 32 , mask 34 , and upper frame 36 may be formed from any suitable material, like aluminum, characterized by an acceptable thermal and electrical conductivity. An exemplary mask 34 is formed from a five (5) mm thick sheet of aluminum and the concavities 46 are arranged and positioned at locations corresponding to the arrangement and positioning of the three-dimensional features 28 of the substrate 20 .
[0030] In an alternative embodiment of the invention, the recesses 42 in the lower plate 32 may be directly formed into the electrode 24 . The recesses 42 , which serve to prevent lateral movement of the masks 34 and to locate the masks 34 at fixed positions relative to the windows 50 in upper frame 36 , may be replaced by any structure capable of preventing lateral movement. Alternatively, if lateral movement of the individual masks 34 relative to the upper frame 36 is not a concern, such as if masks 34 are all coupled together, the lower plate 32 may be omitted in its entirety.
[0031] In an exemplary intended use of the plasma treatment system 10 , each of the substrates 20 may be a lead frame having semiconductor die encapsulating packages as three-dimensional features 28 and each mask 34 is configured with concavities 46 dimensioned and arranged for masking the packages of the lead frame. The lead frame is plasma treated to remove thin layers of molding material (i.e., flash) created by a molding process during a previous manufacturing stage.
[0032] The present invention overcomes the various deficiencies of conventional removal techniques as extraneous material is removed from a substrate 20 without resort to wet chemical etching techniques, mechanical techniques, or the use of a laser, and without damaging the substrate 20 . The process of the present invention is particularly applicable for removing unwanted thin layers of molding material or flash covering the electrical contacts of a lead frame. Flash results from the molding process encapsulating die carried by the lead frame inside respective packages constituted by the molding material.
[0033] In use and with reference to FIGS. 1-5 , the masks 34 are positioned in the recesses 42 defined in the lower plate 32 , which rests on the powered electrode 24 , and are oriented with the concavities 46 facing away from the electrode 24 and lower plate 32 . The substrates 20 are then associated with the masks 34 such that the three-dimensional features 28 carried by each substrate 20 are received in the corresponding set of concavities 46 . Finally, the upper frame 36 is positioned on the substrates 20 held by the masks 34 . The engagement between key pins 54 of the upper frame 36 and the corresponding key bores 56 defined in the lower plate 32 registers the lower plate 32 and upper frame 36 during assembly of the shielding assembly 30 .
[0034] Adjacent to some or all of the three-dimensional features 28 are structures 58 , of which one structure 58 is shown in the detailed view of FIG. 5 . The structures 58 may be, for example, the exposed electrically conductive leads of a lead frame. Areas 60 on the structure 58 may be covered by a thin layer of extraneous material, such as flash from a molding operation creating a package encapsulating a semiconductor die, that the plasma processing is intended to remove.
[0035] After the shielding assembly 30 is assembled, the processing space 14 is then evacuated by vacuum pump 16 . A flow of process gas is introduced from process gas source 18 to raise the partial vacuum in the treatment chamber 12 to a suitable operating pressure, typically in the range of about 150 mTorr to about 1200 mTorr, while actively evacuating the processing space 14 with vacuum pump 16 . The power supply 22 is energized for supplying electrical power to the electrode 24 , which generates plasma 26 in the processing space 14 proximate to the substrate 20 and DC self-biases the electrode 24 . The substrate 20 is exposed to reactive species from the plasma 26 in a treatment process suitable for removing the thin layer of extraneous material from the covered areas 60 ( FIG. 5 ) on the substrate 20 .
[0036] The plasma 26 contains reactive species, including atomic radicals and ions, that interact with material on the surface of the substrate 20 being modified. Extraneous material in covered areas 60 ( FIG. 5 ) of the substrate 20 is transformed by surface reactions with the atomic radicals and ions to a volatile gaseous reaction product that leaves the surface as a gas, which is evacuated from the treatment chamber 12 by the vacuum pump 16 . Flash constituted by a variety of different materials, such as different types of molding materials used to encapsulate semiconductor die, may be removed using different plasma compositions. Any surface reaction residue may be removed by providing a different plasma composition.
[0037] While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants' general inventive concept. The scope of the invention itself should only be defined by the appended claims, wherein we claim: | Apparatus and methods for shielding a feature projecting from a first area on a substrate to a plasma while simultaneously removing extraneous material from a different area on the substrate with the plasma. The apparatus includes at least one concavity positioned and dimensioned to receive the feature such that the feature is shielded from the plasma. The apparatus further includes a window through which the plasma removes the extraneous material. The method generally includes removing the extraneous material while shielding the feature against plasma exposure. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates generally to a coping assembly for capping or covering the edge of a building structure wall and, more particularly to such a coping assembly that is adapted to accommodate walls of varying or inconsistent thicknesses.
Frequently a masonry or frame wall, such as a parapet wall extending above the roof line of a building structure, for example must be covered along its upper edge to prevent weather elements from entering through the top or edge of the wall. Such walls are typically finished at the top or edge with coping assemblies, which can consist of masonry constructions, composition constructions, or metal coping assemblies. Such metal coping assemblies have been found to be particularly successful in providing a waterproof cap, as well as an aesthetically pleasing appearance, especially when coupled with a decorative fascia member.
One disadvantage to typical metal coping assemblies is the fact that the coping assembly components must be fabricated off-site and then delivered to the building construction jobsite. However, the walls on which the coping is to be installed are frequently not constructed to exact design widths or thicknesses, or even to consistent widths or thicknesses. In fact, some masonry walls vary as much as three to four inches from the specified design width, and the widths of such walls can also vary considerably along the length of a given wall. Such variations thus require careful field measurements, frequently necessitating that the ordering and specifying of coping materials cannot be done until after the wall is completed, thus causing construction delays and possible premature deterioration of unprotected walls while the building contractor awaits delivery of coping components.
Thus the need has arisen for a coping assembly for a wall, such as a parapet wall, that can accommodate a variety of wall widths, and which can compensate for varying widths along the length of a given wall. The present invention seeks to meet this need by providing a coping assembly for a parapet wall on a building structure that can provide a weather-tight seal while accommodating varying or inconsistent wall widths, with the parapet wall having generally vertical inner and outer vertical surfaces interconnected by a generally horizontal upper surface. Coping assemblies according to the present invention include a preferably resilient clip member, a clip attachment device for attaching the clip member to the vertical outer surface of the parapet wall, a fascia member, a top plate member, and a top plate anchoring device for anchoring the top plate to the vertical inner surface of the parapet wall.
The clip member includes a generally vertical clip leg for overlapping a portion of the vertical outer surface of the parapet wall, a generally horizontal clip leg for overlapping a portion of the horizontal surface of the parapet wall, and a resiliently deflectable sloping clip leg extending transversely to the horizontal clip leg. The vertical clip leg has a lower hooked clip edge thereon, and the sloping clip leg has an upper hooked clip edge thereon.
The fascia member similarly has a generally vertical fascia leg and a generally horizontal fascia leg, with the vertical fascia leg having a lower hooked fascia edge or drip edge thereon for interlockingly engaging the lower hooked clip edge. The generally horizontal fascia leg overlaps at least a portion of the resilient sloping clip leg and has a generally downwardly-directed protrusion thereon for engaging the upper hooked clip edge in a snapped-on relationship after the lower hooked fascia edge and the lower hooked clip edge have been interlockingly engaged with one another.
The top plate member also has a generally vertical plate leg for overlapping a portion of the vertical inner surface of the parapet wall and a generally horizontal plate leg for overlapping a portion of the horizontal surface of the parapet wall. The horizontal plate leg extends outwardly to overlap a portion of the resilient sloping clip leg and to underlap a portion of the horizontal fascial leg such that the horizontal plate leg is resiliently and clampingly engaged therebetween when the fascia member is snapped onto the clip member. This feature allows the coping assembly to accommodate a variety of parapet wall thicknesses or widths between the vertical inner and outer surfaces of the parapet wall, while still substantially preventing the entry of moisture or debris.
A plate anchoring device is also provided for anchoring the vertical plate leg to the vertical inner surface of the parapet wall. Preferably, such plate anchoring is provided by a hold-down member having a generally vertical hold-down leg for overlapping a portion of the vertical inner surface of the parapet wall and a generally horizontal hold-down leg for overlapping a portion of the horizontal surface of the parapet wall. The vertical hold-down leg is disposed between the vertical inner surface of the parapet wall and the vertical plate leg and includes a lower hooked hold-down edge thereon. The vertical plate leg has a lower hooked plate edge or drip edge in this preferred form of the invention for interlockingly engaging the lower hooked hold-down edge. Preferably a fastener is provided for attaching the vertical hold-down leg to the vertical surface of the parapet wall.
Although not essential to the invention in most applications, a sheet-like sealing membrane can be installed in an overlapping relationship with the vertical and horizontal surfaces of the parapet wall, extending either under or over the resilient clip member in order to provide additional rain and condensation protection. As a further option, a sealing member or sealant bead can be provided between the horizontal fascia leg and the horizontal plate leg for even further sealing protection.
Additional objects, advantages, and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial perspective view of an exemplary parapet wall having an exemplary preferred form of a coping assembly according to the present invention installed thereon.
FIG. 2 is a partial cross-sectional view showing a variation on the coping assembly of FIG. 1.
FIG. 3 illustrates a further variation on a fascia member of a coping assembly according to the present invention.
FIG. 4 illustrates still another variation on a fascia member for a coping assembly according to the present invention.
FIG. 5 is a partial cross-sectional view, illustrating still another alternate construction of a coping assembly according to the present invention.
FIG. 6 is a partial perspective view, similar to that of FIG. 1, but illustrating a further alternate embodiment, with an alternate arrangement for securing the resilient clip member to the parapet wall.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 6 illustrate various preferred embodiments of a coping assembly according to the present invention, shown for purposes of illustration in a parapet wall installation. One skilled in the art will readily recognize, however, that the present invention is not restricted to the coping assembly constructions and configurations depicted merely for purposes of illsutration in the drawings, and further is equally applicable to capping applications other than vertical walls or parapet walls for building structures.
FIG. 1 illustrates one preferred embodiment of the present invention, depicting an exemplary application of the invention in a building structure 10 having a generally vertical parapet wall 12 disposed at or adjacent the edge of a roof for the building structure 10. The parapet wall 12 includes a generally vertical inner surface 14 and a generally vertical outer surface 16, with the inner and outer vertical surfaces 14 and 16 being interconnected by a horizontal surface 18. An exemplary coping assembly 26 according to the present invention serves as a covering or cap for the parapet wall 12 in order to prevent the seepage or rain, snow, or condensation onto the top horizontal surface 18 of the parapet wall 12.
The exemplary coping assembly 26 generally includes a resilient clip member 30, a fascia member 50, a top plate member 70, and preferably a hold-down member 90. The clip member 30 has a generally vertical clip leg 32, a generally horizontal clip leg 34, and a generally sloping clip leg 36, which is resiliently deflectable during installation of the fascia member 50 so as to exert a generally upwardly and inwardly-directed resilient biasing force or clamping force indicated diagrammatically by the arrow 48. The vertical clip leg 32 is adapted for overlapping at least a portion of the vertical outer surface 16 of the parapet wall 12 and includes a lower hooked clip edge 38 protruding generally downwardly and outwardly therefrom. The horizontal clip leg 34 is similarly adapted for overlapping at least a portion of the generally horizontal surface 18 of the parapet wall 12, and includes an upper hooked clip edge 40 thereon. An attachment fastener 42, which can be any of a number of well-known conventional fastener devices, is provided for attaching and anchoring the vertical clip leg 32 to the vertical outer surface 16 of the parapet wall 12.
The fasica member 50 includes a generally vertical fascia leg 52, having a lower hooked fascia edge or drip 56 and a generally horizontal fascia leg 54 having a generally downwardly-directed protrusion or discontinuity 58 thereon. The lower hooked fascia edge 56 is adapted for interlockingly engaging the lower hooked clip edge 38, after which the fascia member 50 can be securely snapped onto the resilient clip member 30, with the downwardly-directed protrusion 58 engaging the upper hooked clip edge 40 of the clip member 30. As the fascia member 50 is snapped onto the clip member 30, the resilient sloping clip leg 36 is deflected downwardly until the downwardly-directed protrusion 58 engages the upper hooked clip edge 40, as mentioned above. Preferably, a number of the downwardly-directed protrusions 58 are disposed on the generally horizontal fascia leg 54 for interlockingly engaging the upper hooked clip edge 40 along the length of the fascia member 50, thus assuring a snug fit and retention of the fascia member 50, with the resilient sloping clip leg 36 exerting the above-mentioned resilient biasing or clamping force 48 on the overlapping horizontal fascia leg 54.
The top plate member 70 includes a generally vertical plate leg 72 and a generally horizontal plate leg 74. The horizontal plate leg 74 extends across the top of the parapet wall 12 to overlap a substantial portion of the horizontal surface 18, as well as overlapping a portion of the resilient sloping clip leg 38 and underlapping a portion of the horizontal fascia leg 54 in order to be resiliently and clampingly engaged therebetween when the fascia member 50 is snapped onto the clip member 30.
In the preferred embodiment depicted in FIG. 1, the hold-down member 90 includes a generally vertical hold-down leg 92 and a generally horizontal hold-down leg 94, with the vertical hold-down leg 92 having a hooked hold-down lower edge 96 thereon for interlockingly engaging the hooked plate edge 78 of the top plate member 70. An anchoring fastener 98, which can be any of a number of well-known conventional fastening devices, is provided for anchoring the generally vertical hold-down leg 92 to the vertical inner surface 14 of the parapet wall 12. Thus, by way of the above-mentioned interlocking engagement between the lower hooked hold-down edge 96 and the lower hooked plate edge 78, along with the resilient and clamping engagement of the horizontal plate leg 74 between the resilient sloping clip leg 36 and the horizontal fascia leg 54, the top plate member 70 is securely retained on the parapet wall 12, and thus the coping assembly 26 serves as a cap or cover to protect the parapet wall 12. In this regard, although not felt to be necessary in most applications, an optional sealant member or bead 60 can be provided between the horizontal plate leg 74 and the horizontal fascia leg 54 in order to further minimize the possibility of moisture seepage onto the parapet wall 12. In addition, although it is not deemed to be necessary for the success of the coping assembly 26 in most applications, a sheet-like sealing membrane 20 can be installed in an overlapping relationship with the parapet wall 12, and can sealingly extend between the clip member 30 and the parapet wall 12, as shown in FIG. 1, or alternately can sealingly extend between the clip member 30 and the top plate member 70.
Preferably, adjacent fascia members 50 along the parapet wall 12 are disposed end-to-end in an overlapping relationship with one another, and similarly adjacent top plate members 70 are similarly overlapped, as shown by the overlapping ends 76 in FIG. 1. In addition, the preferred generally horizontal fascia and plate legs 54 and 74, respectively, are sloped slightly downwardly and inwardly for moisture run-off, with the preferred horizontal fascia leg 54 having a sloped inner edge portion 62.
One of the primary advantages of the present invention, which applies equally to all of the embodiments disclosed and described herein, is the provision of the separate fascia member 50 and top plate member 70, with the horizontal plate leg 74 "telescopically" extending a sufficient distance between the clip member 30 and the fascia member 50 such that variations or inconsistencies in the width or thickness of the parapet wall 12 can be accommodated due to the telescoping interrelationship between the top plate member 70 and the fascia member 50, with their horizontal legs 74 and 54, respectively, being in an overlapped relationship. In this regard, width variations among various parapet walls, or width inconsistencies along a given parapet wall, can be accommodated within a predetermined range of such variations or inconsistencies which is generally equal to the amount of overlap between the horizontal fascia leg 54 and the horizontal plate leg 74. Further in this regard, it should be noted that if the parapet wall is too narrow, such that the horizontal plate leg 74 would extend inwardly between the horizontal fascia leg 54 and the sloping clip leg 36 to an extent that it would abut or interfere with the upper hooked clip edge 40, the horizontal plate leg 74 can be field trimmed to an approximately correct width to allow the coping assembly 26 to be assembled generally as shown in FIG. 1.
It should be noted that the generally downwardly-directed, discrete protrusions 58 formed in the horizontal fascis leg 54 shown in FIG. 1 can be any of a number of leak-proof protrusions known to those skilled in the art, with one preferred form of the protrusions 58 being the joint formed by an apparatus marketed under the trademark Tog-L-Loc, and manufactured by BTM Corporation of Marysville, Mich.
FIG. 2 illustrates an alternate construction of a coping assembly 126 according to the present invention, which is generally similar to the coping assembly 26 described above and illustrated in FIG. 1, except that the hold-down member 90 is eliminated and the top plate member 170 is anchored directly to the vertical inner surface 14 of the parapet wall 12.
The alternate top plate member 170 includes a generally horizontal plate leg 174 and a generally vertical plate leg 172. A recessed portion 182 is formed in the generally vertical plate leg 172, with a fastener opening 180 being provided within the recessed portion 182 for receiving an anchoring fastener 198 in order to anchor the vertical plate leg 172 to the vertical inner surface 14 of the parapet wall 12. In all other respects the coping assembly 126 of FIG. 2 is similar both in function and configuration, to the coping assembly 26 shown in FIG. 1.
FIG. 3 illustrates another variation on the present invention, wherein an alternate fascia member 250 is generally similar, both in function and configuration to the fascia member 50 shown in FIG. 1, with the exception of the provision of one or more generally elongated downwardly-directed protrusions 258 along all or at least a substantial portion of the length of the fascia member 250. The downwardly-directed protrusions 258 can be formed by stamping, punching, or other means well-known to those skilled in the art during the formation of the fascia member 250.
FIG. 4 illustrates still another variation on the present invention, wherein the alternate fascia member 350 is generally similar to the fascia member 250 shown in FIG. 3, except that a generally continuous, downwardly-directed protrusion 358 is formed by molding, extruding, stamping, bending, or other forming methods well-known to those skilled in the art, and results in a generally smooth, or at least generally continuous, upper surface of the horizontal fascia leg 354. In all other respects, the alternate fascia members 250 and 350 of FIGS. 3 and 4, respectively, are similar to the fascia member 50 shown in FIG. 1, both in configuration and function.
A further alternate construction of a coping assembly according to the present invention is illustrated in FIG. 5. In FIG. 5, the alternate coping assembly 426 is generally similar to those described above in the previously-discussed embodiments, except that the clip member 430 includes a generally vertical riser portion 446 between the resilient sloping clip leg 436 and the upper hooked clip edge 440. Similarly, the fascia member 450 includes a somewhat higher vertical fasica leg 452, with a sloping portion 466 formed in the otherwise generally horizontal fascia leg 454, with one or more downwardly-directed protrusions 458 formed in the sloping portion 466 for engaging the upper hooked clip edge 440. It should be noted that the configuration of the downwardly-directed protrusion or protrusions 458 can optionally be that of the discrete protrusions 58 shown in FIGS. 1 or 3, or by the generally continuous protrusion 358 shown in FIG. 4. Such alternate construction, as shown in FIG. 5, can be particularly advantageous or desirable in applications where a higher profile member is desired for aesthetic or other purposes in a given application. In all other respects, the alternate coping assembly 426 is similar in both configuration and function to the previously-discussed exemplary and illustrative embodiments shown in FIGS. 1 through 4.
Finally, FIG. 6 illustrates still another alternate construction of the present invention, which is also generally similar to those previously discussed. In FIG. 6, however, an alternate, preferably resilient clip member 530 is secured to the parapet wall 12 by way of an intermediate tab strip member 584, having a generally horizontal strip leg 585 and a generally vertical strip leg 586, with a number of tabs 587 formed in an initially outwardly-protruding, generally horizontal configuration.
The clip member 530 corresponding slots 541 formed in its vertical clip leg 532 for receiving the tabs 587, which are then bent or otherwise deformed generally downwardly to interlockingly attach or secure the clip member 530. Prior to inserting the tabs 587 through the slots 541, however, the tab strip member 584 is secured to the parapet wall 12 by way of any of a number of well-known high-strength construction adhesives, with the adhesive penetrating through a plurality of adhesive holes 588 through the horizontal strip leg 585 in order to enhance the strength of the bond. An optional attachment fastener 542 can be employed in lieu of, or in addition to, the construction adhesive in suitable applications where fasteners or anchors can be used on the parapet wall 12.
Tab strip members similar to the tab strip member 584, as well as resilient clips similar to the clip member 530, are disclosed and discussed in detail in U.S. Pat. Nos. 4,472,913 and 4,617,770, both of which are assigned to the same assignee as the present invention and are also incorporated herein by reference. In addition to providing for a speedy and convenient installation, another advantage of such an arrangement is that the installer does not have to lean over the edge of the parapet wall to install an attachment fastener for securing the clip member to the parapet wall. Also, the alternate arrangement of FIG. 6 still allows for the inclusion of the optional sheet-like roofing membrane 20, which can overlie the tab strip member 584, under the clip member 530, similar to the arrangement shown in FIG. 1, except that the membrane 20 would extend only over the vertical strip leg 585 and would be clamped in place by the clip member 530.
The foregoing discussion discloses and describes exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims. | A coping assembly is disclosed for a parapet wall on a building structure that can accommodate varying or inconsistent wall widths, with the parapet wall having generally vertical inner and outer vertical surfaces interconnected by a generally horizontal upper surface. Coping assemblies according to the present invention include a preferred resilient clip member, a clip attachment device for attaching the clip member to the parapet wall, a fascia member, a top plate member, and a top plate anchoring device for anchoring the top plate to the parapet wall. The fascia member and the top plate member have overlapping or telescoping portions that provide for the feature by which various wall widths or thicknesses can be accommodated. | 4 |
FIELD OF THE INVENTION
The invention is related to the field of Nuclear Magnetic Resonance (NMR) apparatus and methods. Specifically, the invention relates to NMR apparatus and methods using pulsed static magnetic fields.
BACKGROUND OF THE INVENTION
When hydrogen nuclei are placed in an applied static magnetic field, a small majority of spins are aligned with the applied field in the lower energy state, since the lower energy state in more stable than the higher energy state. The individual spins precess about the applied static magnetic field at a resonance frequency also termed as Larmor frequency. This frequency is characteristic to a particular nucleus and proportional to the applied static magnetic field. An alternating magnetic field at the resonance frequency in the Radio Frequency (RF) range, applied by a transmitting antenna to a subject or specimen in the static magnetic field flips nuclear spins from the lower energy state to the higher energy state. When the alternating field is turned off, the nuclei return to the equilibrium state with emission of energy at the same frequency as that of the stimulating alternating magnetic field. This RF energy is generating an oscillating voltage in a receiver antenna whose amplitude and electronic rate of decay depend on the physicochemical properties of the tissue and the magnetic environment of the nuclei. The applied RF field is designed to perturb the thermal equilibrium of the magnetized nuclear spins, and the time dependence of the emitted energy is determine by the manner in which this system of spins return to equilibrium magnetization. The return is characterized by two parameters: T 1 , the longitudinal or spin-lattice relaxation time; and T 2 , the transverse or spin-spin relaxation time.
There are at least two applications in which samples volumes are substantial and bulk material properties are of interest. One of these is logging of wells drilled for hydrocarbon recovery from earth formations and another is whole body fat determination.
Measurements NMR parameters of fluid filling the pore spaces of the earth formations such as relaxation times of the hydrogen spins, diffusion coefficient and/or the hydrogen density is the bases for NMR well logging. NMR well logging instruments can be used for determining properties of earth formations including the fractional volume of pore space and the fractional volume of mobile fluid filling the pore spaces of the earth formations.
Pulsed RF magnetic fields are imparted to the material under investigation to momentarily re-orient the nuclear magnetic spins of the hydrogen nuclei. RF signals are generated by the hydrogen nuclei as they spin about their axes due to precession of the spin axes. The amplitude, duration and spatial distribution of these RF signals are related to properties of the material under investigation. In the well logging environment, contrast is high between free and bound fluids based on their relaxation times, between oil and water based on their relaxation times and diffusion coefficient. In medical applications, tissue contrast is high between fat and muscle based on their relaxation times and can be further enhanced by application of certain RF sequences.
Methods of using NMR measurements for determining the fractional volume of pore space and the fractional volume of mobile fluid are described, for example, in Spin Echo Magnetic Resonance Logging: Porosity and Free Fluid Index Determination , M. N. Miller et al, Society of Petroleum Engineers paper no. 20561, Richardson, Tex., 1990. In porous media there is a significant difference in T 1 and T 2 relaxation time spectrum of fluids mixture filling the pore space. For example, light hydrocarbons and gas may have T 1 relaxation time of about several seconds, while T 2 may be three orders of magnitude smaller. This phenomenon is due to diffusion effects in the presence of gradients in the static magnetic field. The gradients may be external (from the applied static field) or internal. Internal magnetic field magnitude gradients are due to differences in magnetic susceptibility between the rock matrix of the formation and the fluids in the pores of the matrix.
Power requirements in NMR oil well logging have to be optimized for high efficiency operation. In order to perform a valid NMR experiment, a substance should be polarized for about 5 times the longest T 1 relaxation time, which is about 1 second long. Typical Carr-Purcell-Meiboom-Gill (CPMG) pulse sequences are about 0.5 to 1 second long. However, because of low signal-to-noise ratio (SNR), several repetitions of a CPMG sequence are required to bet an adequate SNR.
The earliest NMR logging instruments used the earth's magnetic field for providing the static field for NMR measurements. See, for example, U.S. Pat. No. 3,004,212 to Coolidge et al; U.S. Pat. No. 3,188,556 to Worthington; U.S. Pat. No. 3,538,429 to Baker; and U.S. Pat. No. 2,999,204 to Jones et al. The earth's magnetic field is approximately 60 μT at the poles with a Larmor frequency f for protons of approximately 2.5 kHz. The signal level per unit volume for an NMR survey is approximately proportional to f 7/4 . The early NMR logging instruments suffered from the problem of low resolution because signals from a large volume of the earth were required to get an acceptable SNR. When the earth's magnetic field is used for the static field, there is no problem in having a uniform static field over a large region, so that SNR is not a major problem; however, there are many applications in which high resolution is required. This is difficult to achieve using the earth's magnetic field as the static field for NMR experiments.
In order to achieve high resolution, NMR devices used in recent years for well logging operations use permanent magnets to generate the static magnetic field. These devices typically operate at 1 MHz corresponding to a magnetic field in the region of investigation of 0.0235T. Needless to say, this requires the use of permanent magnets with a strong magnetic field as part of the logging instrument.
For example, U.S. Pat. No. 4,350,955 to Jackson et al discloses a pair of permanent magnets arranged axially within the borehole so their fields oppose, producing a region near the plane perpendicular to the axis, midway between the sources, where the radial component of the field goes through a maximum. Near the maximum, the field is homogeneous over a toroidal zone centered around the borehole. U.S. Pat. No. 4,717,877 to Taicher et al teaches the use of elongated cylindrical permanent magnets in which the poles are on opposite curved faces of the magnet. The static field from such a magnet is like that of a dipole centered on the geometric axis of the elongated magnets and provides a region cf examination that is elongated parallel to the borehole axis. The RF coil in the Taicher device is also a dipole antenna with its center coincident with the geometric axis of the magnet, thereby providing orthogonality of the static and magnetic field over a full 360° azimuth around the borehole. U.S. Pat. No. 6,023,164 to Prammer discloses a variation of the Taicher patent in which the tool is operated eccentrically within the borehole. In the Prammer device, NMR logging probe is provided with a sleeve having a semi-circular RF shield covering one of the poles of the magnet: the shield blocks signals from one side of the probe.
These, and others too numerous to mention, have been used for wireline logging wherein the logging tool is conveyed on a wireline into a borehole, as well as Measurement-While-Drilling (MWD) operations where the logging tool forms part of the drilling assembly. All of these tools typically have a region of investigation no more than a few centimeters into the formation and a few millimeters in thickness. Repeatability of the observations requires that the static magnetic field be predictable to a high level of accuracy. An unappreciated problem in NMR logging of earth formations using strong permanent magnets is that the static magnetic field in the subsurface may not correspond to that expected on the basis of the design of the magnet. This is due to the fact the logging instruments, whether on a wireline or as part of an MWD apparatus, have to pass through several hundreds or thousands of meters of casing that is used to line boreholes. To understand the consequences of this, a brief review of the process of drilling wells is needed.
In the drilling of oil and gas wells, drill bits and other equipment are attached to a drill string for boring a hole into the earth. Typically, a drill string may comprise a long string of many connected sections of drill pipe which extend from the earth's surface down into the wellbore or hole being formed by a drill bit connected at the bottom end of the drill string. As the wellbore penetrates more deeply into the earth, it becomes increasingly desirable to install casing in the wellbore, running down from the surface.
Casing is placed in the wellbore for one of two reasons. The first may be to prevent the wall of the wellbore from caving in during drilling and to prevent seepage of fluids from the surrounding strata into the wellbore. Casing is absolutely essential when drilling through an overpressured section (with an abnormally high fluid pressure requiring heavy drilling muds) into a normally pressured or underpressured section below: in such situations, casing is set after drilling through the overpressured formation and the mud weight is reduced. A second reason may be to prevent damage to the reservoir rocks by the drilling mud in the borehole forcing its way into the formation. Even in normal drilling, it is common to set casing of several different sizes in the borehole.
During rotary drilling operations drill strings are subjected to shock, abrasion and frictional forces which are exerted on the drill string whenever the drill string comes in contact with the walls of the wellbore or casing. Both the drillstring and the casing are usually made of steel, a ferromagnetic material, so that the abrasion forces will result in large quantities of ferromagnetic debris within the casing. There are numerous methods and devices for reducing the abrasion. None of them can be completely effective. Circulating drilling mud during drilling is quite effective in bringing cuttings from the formation to the surface but is not effective in completely flushing the more dense metallic debris out of the borehole.
As a result of this, when an NMR logging tool, whether on a wireline or as part of an MWD apparatus, is conveyed into a borehole through casing, much of the magnetic debris within the casing will attach to the tool. This can distort the static magnetic field produced by the permanent magnets in an unpredictable manner. In addition, since the RF pulses are produced by transmitter coils on the logging tool, the RF field is also distorted. Compounding the problem is the fact that the spin-echo signals also have to pass through this debris. U.S. Pat. No. 5,451,873 to Freedman et al. teaches a method of calibrating an NMR tool to account for the accumulation of magnetic debris on the tool. For a so-called “saddle point” tool used in Freedman, one effect of the debris is to change the static field (and hence the Larmor frequency) in the region of investigation. Freedman makes a one-time adjustment to the tool frequency prior to using the tool. The frequency shift is not necessary for gradient tools since for a fixed frequency, the volume of investigation changes. A continuing problem remains: how to compensate for time varying effects of the debris.
In addition to the signal distortion, there is also the practical problem of conveying a strongly magnetized logging tool several meters long through a ferromagnetic casing. This problem is exacerbated in deviated or horizontal boreholes.
SUMMARY OF THE INVENTION
In one embodiment, the present invention is a method for nuclear magnetic resonance (NMR) sensing of earth formations. An electromagnet on a logging tool is used to induce a static magnetic field for polarization of nuclei within a region of the earth formations. A radio frequency pulse is used to tip the magnetic spins of the nuclei. A receiver is used to measure either the free induction decay or spin echo signals (using a CPMG pulse sequence) from the precessing nuclei. The wait time between the activation of the electromagnet and the initial RF pulse is related to a T 1 of the formations. When the static magnetic field strength is 10-100 times that of the earth's field, it is possible to obtain low resolution estimates of properties of large volumes of earth formation. The logging tool may be conveyed into the earth on a wireline or on a drilling tubular.
In an alternate embodiment of the invention, a time varying static field is produced using an electromagnet. The transmitter and the receiver operate at different frequencies. This reduces the ringing signals in the receiver and, after calibration, provides a measurement of bulk composition
Another embodiment of the invention may be used for estimating fat composition of a human body. A prior art MRI device is operated in accordance with a method of present invention to provide a low intensity static magnetic field, making it possible to obtain low cost body fat and lean measurements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of an NMR tool of the present invention deployed in a borehole.
FIG. 2 is a schematic illustration of a cross-section of an embodiment of a logging device of the present invention.
FIG. 3 shows an alternate embodiment of the present invention including an arrangement of the electromagnet coil, transceiver coil and additional receiver coil for use in logging of wellbores.
FIG. 4 is a schematic illustration of a conventional NMR measurement method.
FIG. 5 is a schematic illustration of a method of making NMR measurements in a time-varying static magnetic field.
FIG. 6 is an illustration of the pulse sequences for a method of making NMR measurements in a time-varying static magnetic field.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is shown an NMR well logging tool 10 conveyed in a borehole 20 within earth formations 30 . For exemplary purposes, the tool is shown conveyed by a wireline 40 . Surface equipment shown at 50 can be of a conventional type and includes a processor that communicates with the downhole equipment. The deployment on a wireline is for illustrative purposes only and the present invention may also be used in Measurement-while-Drilling (MWD) and Logging while tripping (LWT) environments using known prior art configurations including drilling tubulars such as a drillstring or coiled tubing.
As shown in FIG. 1, the tool 10 has a pair of coils, a polarizing coil 3 that forms an electromagnet and an excitation coil 5 wound on a non-conductive core (not shown). In a preferred embodiment of the invention, an axis 4 of the coil 3 , referred to as the polarizing coil, is substantially perpendicular to a longitudinal axis 12 of the borehole and an axis 6 of the coil 5 , referred to as the excitation coil, is substantially perpendicular to the longitudinal axis of the borehole 12 and to the axis 4 of the polarizing coil 3 . FIG. 2 schematically illustrates a cross-section of an embodiment of a logging device of the present invention. The polarizing coil 3 is preferably consists of multiple winding, whereas the excitation coil 5 preferably consists of one or few winding only. This is shown in FIG. 2 .
When an electrical current is passed through the polarizing coil 3 , this produces a static magnetic field in the earth formation 30 in the vicinity of the tool that is substantially perpendicular to the borehole axis 12 . In one mode of operation, the current in the polarizing coil is kept on for a time equal to a few times the largest T 1 value of fluids in the earth formation. Typically, the duration of the polarizing pulse is several seconds. As a result of this polarizing pulse, nuclear spins in the earth formation 30 will become re-oriented substantially parallel to the polarizing field and substantially perpendicular to the borehole axis 12 .
The NMR well logging tool 10 further includes the previously described excitation coil 5 , (further referred to as a transmitter, receiver or transceiver coil) which can comprise one or more coil windings. Radio Frequency (RF) alternating current passing through the coil 5 generates an RF magnetic field in the earth formation 30 substantially perpendicular to the static magnetic field. The free precession of the nuclear magnetic moments around the static magnetic field direction induce an RF signal in the receiver antenna 5 . Such a magnetic field arrangement is conventional for NMR experiments. The RF magnetic field may be modulated by a modulating signal that comprises at least one pulse. When a single pulse with a 90° tipping angle is used and the duration of the polarizing pulse is around T 1 (few milliseconds to few seconds), the amplitude of the signal in the receiver antenna is indicative of T 1 . Alternatively, the at least one pulse may be a sequence of pulses such as a CPMG sequence or a modified CPMG sequence as taught in U.S. Pat. No. 6,163,153 to Reiderman, the contents of which are incorporated herein by reference. Excitation coil 5 is preferably elongated along the longitudinal axis 12 of the borehole and is several times longer than diameter of the borehole 10 . In this case this coil generate a substantially two-dimensional magnetic field within the formation of interest. Such a field is perpendicular to the longitudinal axis 12 at any point within the formation of interest.
In an alternate embodiment of the invention shown in FIG. 3, a polarizing coil 21 in a form of a solenoid electromagnet produces a static magnetic field in the earth formation 30 in the vicinity of the tool that is substantially parallel to the borehole axis 12 . Additionally, instead of a single transceiver coil 5 , a pair of orthogonal coils 22 and 23 are used with coil axes orthogonal to each other and to the borehole axis 12 . Alternatively, the device of FIG. 3 may be used so that coils 22 and 23 are used both as a transmitter and a receiver. One possibility is to use the coil 23 only as a receiver. The second possibility is to use the coil 22 also as receiver to detect an additional component of the spin-echo signals, which is orthogonal to the signal component received in the first receiving coil. The orthogonality of the two coil axes to the axis of the polarizing coil 21 substantially reduces the current induced in the transmitter/receiver coil by the termination of the polarizing pulse. When an electrical current is passed through the polarizing coil 21 , this produces a static magnetic field in the earth formation 30 in the vicinity of the tool that is substantially parallel to the borehole axis 12 .
The tool of FIGS. 1-3 may be easily passed through casing without accumulation of ferromagnetic debris or sticking caused by magnetic attraction to well casing, as there is no permanent magnet on the tool. Low magnetic fields (0.6-6 mT, i.e., 10-100 times the earth's field) are easy to generate by DC currents. In the logging environment and in the case of whole body composition analysis the region of investigation is large so that the SNR is expected to be adequate with measurement times of a few seconds (i.e., with a few repetitions of the CPMG sequence). For that short time a pulse of DC current (low average power requirements) may generate the static magnetic field. Optionally, a capacitor may be used on the logging tool with the capacitor discharge providing the static field. Yet another option is to generate a pulse of static magnetic field only during one sequence.
In an alternate embodiment of the invention, the excitation coil is pulsed after partial polarization of the nuclear spins. The partial polarization time (time between beginning of polarizing pulse and beginning of excitation RF pulse) may range from 0.1 to 5 times the largest value of T 1 in the formation. By making such measurements with several different partial polarization times, information may be obtained regarding the T 1 distribution of the formation.
Conventional NMR measurements are made by applying a predetermined static magnetic field to the region under investigation to partially or fully polarize the nuclear spins. Following this, a RF magnetic field is applied to determine the decay characteristics of nuclear spins. The NMR experiment may involve measurement of free induction decay (FID) or it may involve spin-echo measurements. For example, in a commonly used method of spin-echo measurements, the RF magnetic field comprises a tipping pulse that tips the nuclear spins by 90° and starting a precession of the spins. A series of refocusing pulses is applied and pulse echo signals are measured using a receiver coil. The transmitter and receiver coils may be the same. A conventional NMR method is illustrated in FIG. 4 where the abscissa 101 is time, the ordinate 103 is the magnetic intensity shown by 105 and the measurements are made during a time duration 107 . Regardless of whether FID or spin-echo measurements are made, there are stringent requirements on the stability of the magnetic field (typically 1%) and its gradient. Additionally, if the same antenna is used for transmitting and receiving the RF signals, switching transients may be present. This, and ringing produced by the initial tipping pulse causes problems in making accurate measurements of signal amplitudes. Many of these problems are avoided in the novel procedure described next.
FIG. 5 illustrates the methodology of the present invention. A slowly varying magnetic field is produced by passing a current through a polarizing coil, the field intensity as a function of time being shown by 205 . The RF field is applied at one time interval 207 with a RF frequency corresponding to magnetic field intensity 208 . The static magnetic field produced by the polarizing coil may then increase to some maximum value and then starts decreasing. The measurements are made during a time interval such as 209 when the field intensity 210 (and the corresponding precession frequency) are different from those of the tipping pulse. The advantage of this is obvious since this eliminates the ringing. In addition, stability requirements on the static field are greatly reduced, the main requirement being that the measurements be repeatable. There is no requirement that the nuclear spins be fully polarized, or even that the extent of the partial polarization be known. Furthermore, there is no requirement that the RF pulse tip the nuclear spins by 90°, the only requirement being that of repeatability. Different materials will respond differently and can be calibrated accordingly. For example, water, oil, and gas may have different responses. Once a calibration is performed, the pulsed polarization method may be used for logging of earth formations. This method may be used with the coil configurations described above with reference to FIGS. 1-3.
Those versed in the art would recognize that the temporal variation of the static field such as that shown in FIG. 5 can be easily obtained by discharge of a capacitor. For a given coil configuration, the requirements of stability are easily met.
When static magnetic field spatial distribution at any moment in time is homogenous, it is possible to make FID measurements. The condition of homogeneity is applicable for some cases of whole body composition determination. However, in the logging environment, static magnetic field gradients exist and therefore, a spin-echo measurement have to be implemented. FIG. 6 shows the methodology of performing a spin-echo experiment with a time-varying static magnetic field. The field intensity of the static magnetic field as a function of time being shown by 305 . A first pulse of RF magnetic field is applied at a first time interval 307 with a RF frequency corresponding to magnetic field intensity 306 . The RF field intensity and the duration of this pulse are set to be such, that the nuclear spins are tipped by approximately 90°. The static magnetic field produced by the polarizing coil may then changed to a higher or lower level. FIG. 6 shows the static field being increased. A second pulse of RF field is applied at a second time interval 309 with a RF frequency corresponding to static magnetic field intensity 308 . The RF magnetic field intensity and the duration of this pulse are set so that the nuclear spins are tipped by approximately 180°. Since the static magnetic field is inhomogeneous, the timing of the 90° and the 180° pulses is important. The measurements are made during a time interval such as 311 when the field intensity 310 (and the corresponding precession frequency) are different from those of the tipping and the refocusing pulses. Proper timing of the tipping and refocusing pulses is important due to the field variation.
At each point in space the static magnetic field is related to the electrical current which generate the field. For the NMR well logging equipment shown in FIGS. 1-3, the regions of equal static magnetic field form cylindrical shells. Therefore, if the first pulse of RF magnetic field is applied at time interval different from time interval 307 with a RF frequency corresponding to magnetic field intensity 306 , nuclear spins at different shell will be tipped. Timing of the 90° and the 180° can be easily calibrated by adjusting received signal to maximum amplitude.
The method has been described above using a single refocusing pulse followed by the reception of a single echo. The method may be generalized to include a plurality of refocusing pulses with a varying time interval therebetween and receiving a corresponding set of echos. Additionally, measurements made at different depths in a borehole may be deconvolved using known signal processing techniques to improve the resolution of the estimated properties of the formation.
While the foregoing disclosure is directed to the preferred embodiments of the invention, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure. | An apparatus and method for making NMR measurements uses an electromagnet for producing the static magnetic field. When used in well logging applications, the absence of a strong permanent magnet eliminates almost completely the amount of ferromagnetic debris picked up on the logging tool when passed through casing. The absence of debris results in the static magnetic field being substantially in conformance with design. The electromagnet is designed to give a static field of 0.6-6 mT (10-100 times the earth's magnetic field). Free induction decay or spin echo measurements may be made to give low resolution measurements of bulk properties of earth formations. The same coil configuration may be used to estimate body fat measurements of a human body. An alternate embodiment of the invention uses a capacitive discharge through an electromagnet with a time varying magnetic field with the receiver operating at a different frequency from the transmitter. | 6 |
BACKGROUND OF THE INVENTION
In solar photovoltaic systems, modules are typically connected in series-parallel arrangements. Series-aiding strings of twelve or more modules are common. The number of modules per string sets the system voltage. The number of series strings wired in parallel sets or is proportional to the system power. Large, prior art central-inverter-based systems use two tiers of DC power collection. First, a number of series strings are routed to a field combiner box which provides overcurrent protection, via a fuse, for each string conductor (and series module in that string) and combines, or electrically parallels, all string circuits at a field combiner box output. Second, each field combiner box output is routed to a master combiner box input. The master combiner box provides overcurrent protection for conductors between the field combiner boxes and the master combiner box and combines all the field combiner box outputs into a single DC feed for the central inverter. The master combiner box is typically adjacent to the central inverter and field combiner boxes are distributed throughout the array field.
Functionally, all fuses in a photovoltaic system are primarily there to protect from backfed currents. For example, if one series string in a megawatt-scale system is shorted, the available fault current will be the short circuit current of the entire megawatt photovoltaic source. The National Electric Code specifies that all conductors in a photovoltaic system be protected from all sources of current; current in the normal direction of flow as well as backfed current.
Fault currents from photovoltaic sources are very different from fault currents in AC systems because shorted photovoltaic sources behave like current sources. A shorted series string of irradiated photovoltaic modules will typically source only 10% more current than under normal operating conditions. As such, series string fuses are sized to never clear in the direction of forward current.
The cost of providing overcurrent protection for every series string is significant and more so in systems employing thin-film solar modules. Thin-film module currents are typically 4 to 5 times less than crystalline module currents. As such, the number of fuses and conductor runs to field combiner boxes are typically 4 to 5 times greater.
BRIEF SUMMARY OF THE INVENTION
The invention enables improvements in solar photovoltaic (PV) system DC power collection.
The preferred embodiment is a sealed sub-combiner unit for combining a small number of series strings, at the field terminus location of these series strings, in order to significantly reduce the number of conductors run to the field combiner box location or to the next tier of DC power collection. The sub-combiner is fitted with standard connectors for direct attachment to solar modules. The invention leverages the fact that series string fuses rarely open. As such, the cost and safety issues of providing access to these fuses are eliminated. If a fuse does clear, the small, low cost sub-combiner is designed for plug-and-play replacement. There are, by design, no user-serviceable sub-combiner parts. In one embodiment, the sub-combiner is potted to significantly enhance the environmental integrity of this approach over prior art methods and to further reduce the size and therefore the cost of materials per series string connection.
A second and closely related embodiment is a method of completely eliminating prior-art string combiner boxes by creating a two-conductor monopolar or three-conductor bipolar DC power collection buss for each master combiner or “home run” circuit. Each series string will tap into the applicable DC buss conductor via a local fused or non-fused (depending on the grounding disposition of the conductor) sub-combiner close to the terminus of two to eight series strings.
UTILITY OF THE INVENTION
The invention finds the greatest utility when used with thin-film photovoltaic cell technologies where the number of series strings, and therefore required string fuses and support infrastructure, is typically 4 to 5 times the cost of that required for crystalline cell technologies.
The invention can significantly reduce material costs, labor costs and normalized I 2 R losses associated with DC power collection. The total weight of copper in series string-to-combiner circuit runs, in thin-film applications, can be reduced by approximately 67%. The number of field wiring connections can be reduced by an order of magnitude. Unskilled personnel can change out a blown fuse by simply replacing the entire touch-safe sub-combiner.
The invention leverages two principles. First, the fact that in a well designed PV system only 1 in 5,000 fuses may clear in the lifetime of that system, making ease of fuse replacement a cost ineffective luxury. Second, the maturity of the photovoltaic industry is recognized where ease of circuit access, via a conveniently located combiner box for troubleshooting, now provides less value than does the cost reduction, enhanced reliability, system simplification and enhanced personnel safety enabled by the invention. In lieu of intentionally opening string circuits and probing hot string conductors with a voltmeter, troubleshooting can be accomplished at distributed sub-combiner locations with a clamp-on DC current probe with no exposure to hazardous voltages.
Typical “failures” in state-of-the-art PV combiner boxes may not be directly caused by the intended clearing of a fuse. In most cases thermal cycling, condensation, particulate contamination, insect intrusion and/or corrosion may cause high resistance contacts between wiring terminals and fuse to fuse holder contact areas. In some cases and over time, this may cause fuses to operate at higher than rated temperatures so that a 10 A fuse effectively becomes a 7 A fuse and may clear. In other cases, power production from a series string may cease with the fuse intact as terminals oxidize and corrode to a point where contacts become insulators.
The invention provides a sealed environment for fuses and connections. In one embodiment of the invention, fuses and conductors to/from MC4 connectors are soldered to a PCB (Printed Circuit Board) assembly and the entire assembly is potted with a thermally conductive encapsulant. The resulting IP67 or NEMA 6 rated sub-combiner may provide long term reliability figures ten times that of any state-of-the-art PV string combiner equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a layout and electrical connections for a two input combiner with input and output DC buss connectors.
FIG. 2 compares the photovoltaic subarray DC power collection approach for a prior-art solution and a solution using the invention.
FIG. 3 details the electrical circuit of the solution in FIG. 2D using the invention.
FIG. 4 illustrates a layout and electrical connections for a four input combiner with input and output DC buss connectors and an optional insulation displacement DC buss connector.
FIG. 5 is a not-to-scale schematic drawing that illustrates how the combiner described in FIG. 4 would be connected in a solar field for maximum benefit.
FIG. 6 illustrates a layout and electrical connections for a two input combiner with one output.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a preferred embodiment of the invention as a sub-combiner for combining positive conductors from two series strings as well as supplying positive buss input and output connectors.
FIG. 1A shows a top view of the sub-combiner. Connectors 1 , 20 , 30 are standard male MC4 conductors, the type that mate with the positive connector on a standard PV module. Connector 2 is a standard female MC4 conductor, the type that mates with the negative connector on a standard PV module or, as in this case, the type that are used to extend the conductor length of a positive circuit. Electrical connections 21 and 31 are made from connectors 20 and 30 to one end of fuses 22 and 32 , respectively. The remaining ends of fuses 22 and 32 are electrically connected in common with connectors 1 and 2 as shown by circuit 3 . Fuses 22 and 32 are soldered to printed circuit board 90 . In practice, connectors 20 and 30 will each be connected to the positive pole of the last module in a unique series string. The sub-combiner is intended for use with other sub-combiners where output connector 2 of the first sub-combiner in a daisy-chain will connect through an appropriately MC4-terminated cable to input connector 1 of the second sub-combiner in the daisy chain and so on, such that circuit 3 is common to all sub-combiners and acts as a positive DC power collection buss. For example, in a four sub-combiner daisy-chain, the current out of terminal 2 of the fourth sub-combiner will be the sum of eight series string currents. Reference designator 7 indicates one of two mounting holes.
FIG. 1B shows a side view of the sub-combiner with cover 8 in place. In this embodiment of the invention, cover 8 may be glued, welded or otherwise permanently affixed. Enclosure 6 may also be filled with an electrically insulating potting material 9 , shown in FIG. 1A , to provide a higher level of environmental integrity, to reduce circuit spacing requirements or to prevent exposure to hazardous voltages. If cover 8 is not used, then enclosure 6 will be filled with an electrically insulating filler to cover all live components. The filler may also be thermally conductive in order to transfer waste heat generated by the fuses. In either case, the sub-combiner will be environmentally sealed to IP67 or NEMA 6, will be touch-safe and will have no user serviceable components.
In FIG. 1 , if the grounded conductors of a series string were being combined the sub-combiner would be identical to that in FIG. 1 except that fuses 22 and 32 would be replaced by short circuits.
FIG. 2 illustrates the advantages of the invention compared to prior art solutions.
FIG. 2A illustrates typical prior art DC power collection from a photovoltaic subarray with eight series strings, A through H, each comprising fourteen thin-film modules. In FIG. 2A module-to-module connections are not shown, for clarity.
FIG. 2C is a detail of the dashed-line area shown in FIG. 2A . A pair of conductors must be routed from each of the eight series string circuits to a combiner box location X. Based on the layout shown with 1200 mm by 600 mm module dimensions, the total wire length is 300 m with a conductor cross section of 4 mm 2 (˜14 AWG). The string current under nominal conditions is 1.32 A. Module dimensions and nominal current specifications are based on a widely used thin-film module.
FIG. 2D is a detail of FIG. 2B and illustrates an improved DC power collection method using the sub-combiner described in FIG. 1 . With this method the total wire length is 64 m with a conductor cross section of 6 mm 2 (˜10 AWG). The ratios of copper length times cross section or therefore volume or weight is 3:1 for the prior art approach vs. the solution enabled by the invention and for the conductors shown in FIGS. 2A and 2B .
FIG. 3 is a functional schematic of the power collection methodology illustrated in FIG. 2D and includes sub-combiners 100 and 200 as described in FIG. 1 and the associated FIG. 1 narrative. All plug-to-plug connections in FIG. 3 are shown disconnected so that the connector gender is well indicated. Because MC4 connectors are shrouded in order to be touch-safe, the gender descriptions and illustrations may not appear to agree. In FIG. 3 , the positive DC buss is split into conductors 101 and 102 , and are terminated with female MC4 connector 110 and male MC4 connector 113 , respectively. In a similar way, the negative DC buss is split into conductors 201 and 202 , and are terminated with male MC4 connector 210 and female MC4 connector 213 , respectively. To complete the circuit, positive DC buss connectors 110 and 113 are plugged into sub-combiner high current inputs 111 and 112 , respectively. In a similar way negative DC buss connectors 210 and 213 are plugged into sub-combiner high current inputs 211 and 212 . In this application, the DC busses are split to enable daisy-chained power collections and touch-safe, plug-and-play installation and replacement of sub-combiners 100 and 200 , although it is highly unlikely that non-fused sub-combiner 200 will ever need to be replaced. Series strings G and H are each made up of 14 thin-film solar modules connected in series with typical module-to-module interconnections as illustrated by connectors 75 / 72 and 85 / 82 , respectively. Module-to-module connections interior to either string G or H are not shown for clarity. DC power is collected or currents combined by plugging female MC4 connector 71 and 81 from modules G1 and H1 into sub-combiner input ports 120 and 130 , respectively. When connected, currents flow from strings G and H through fuses 114 and 115 , respectively, and into DC buss conductor 102 . In a similar way currents are combined by plugging male MC4 connector 76 and 86 from modules G14 and H14 into sub-combiner input ports 220 and 230 , respectively. When connected, currents return from strings G and H through DC buss conductor 202 .
By way of a more quantitative example, if PV modules with short circuit current (I sc ) ratings of ˜2 A and sub-combiners supplied with 3.5 A fuses were used for the application described in FIGS. 2 and 3 , then eight series strings could be combined into one 16 A (I sc ) circuit and the “DC buss conductors” could simply be 6 mm 2 Type PV wire. In this overall system scenario, three-tiers of DC power collection would be used; a sub-combiner tier, a field combiner box tier with one-eighth the fuses and conductors entering the combiner box and a master combiner box tier.
FIG. 4 illustrates a logical extension of the sub-combiner described in FIG. 1 but with four series string input connectors 20 , 30 , 40 , 50 with circuit connections 21 , 31 , 41 , 51 and fuses 22 , 32 , 42 and 52 , respectively. Fuses 22 , 32 , 42 and 52 are soldered to printed circuit board 90 . In some applications, the daisy-chain function may be extended to currents higher than the standard MC4 connector 30 A limit by deleting or not using input connector 1 and by using cable assembly 60 , with male MC4 connector 61 , conductor 62 and insulation displacement tap connector 63 where tap connector 63 is connected to a high current DC buss conductor. If the DC buss conductor is sized to carry the current of a master combiner or “home run” circuit, the traditional field combiner box can be eliminated. In lieu of an insulation displacement tap connector, a junction box could also facilitate this connection by breaking the buss conductors and connecting each end to a common terminal block inside the junction box. A lower current connection from the same terminal block will also be made to a bulkhead MC4 connector accessible from the exterior of the junction box. In this way, touch-safe plug-and-play installation and replacement of the combiner box may also be accommodated.
FIG. 5A illustrates the optimum solar module arrangement for the sub-combiner illustrated in FIG. 4 where series strings A through F are arranged in a row so that four positive conductors of four unique series strings terminate at a common location and where four negative conductors of four unique series strings terminate at a common location along the length of a row. The row shown is comprised of eight series strings but could be much longer and is only limited in length by the cross sectional area of DC buss conductors 102 and 202 .
FIG. 5B is a detail of the FIG. 5A area bounded by dashed lines. FIG. 5B is not to scale and is use here to schematically illustrate how sub-combiner 10 is connected to four unique series string circuits using only the standard terminations supplied with the solar modules. Module-to-module connections 18 and 19 are also made as intended with the standard manufacturer-supplied connectors. In this example, the output of combiner 10 is connected to positive DC bus conductor 102 with self-sealing, insulation displacement tap connector 63 . Buss conductor 102 could, for example, be a typical stranded conductor with RHW-2 insulation, an insulated aluminum buss bar or any other method for efficiently conducting higher cumulative currents than could be handled by “standard” MC4 type connectors.
FIG. 6A shows the simplest embodiment of the invention as a three port device with male MC4 connector-based lower current input ports 1 and 9 to conduct current through electrical contacts 2 and 8 and through fuses 3 and 7 , respectively, to a common higher current connection point 5 and female MC4 connector 6 . The combiner assembly is injection molded as a single piece from an electrically insulating and physically robust and sunlight resistant plastic. FIG. 6B is for connection to negative PV module terminals but is otherwise analogous in function and construction to the combiner described in FIG. 6A . Each combiner may also have provisions, not shown, for mounting the combiners to the array structure. These provisions may include mounting holes to facilitate mounting with a plastic tie-wrap fastener.
In an additional photovoltaic combiner embodiment, not illustrated, combiner fuses are replaced by diodes. The diodes serve the same function as the fuses by preventing damaging backfed currents in series string conductors and series connected solar modules. The use of diodes also supports the basic utility of the invention; that of providing a maintenance-free, touch-safe distributed method of combining circuits. Both fuses and diodes generate waste heat under normal operating conditions and, as such, all other parameters and disclosures associated with the fuse-based invention would be equivalent in a diode-based solution with the exception that there would be more heat to be removed using the diode solution. | An improved method of collecting DC power in solar photovoltaic systems is disclosed where series string overcurrent protection is provided at distributed series string terminus locations and a tap connection is made to higher current conductors carrying the combined currents of a number of series strings. A number of related string combiner methods and embodiments are disclosed. | 8 |
FIELD OF THE INVENTION
The present invention generally relates to a method and means of repairing a manhole. More particularly, but not exclusively, the invention relates to a method and assembly for lining a manhole wall.
BACKGROUND OF THE INVENTION
Conventional manholes include a lower or bottom pad, a barrel having a relatively constant diameter adjacent the pad, a concentric or eccentric cone extending upwardly from the barrel, one or more adjusting rings to adjust the overall height of the manhole, and a casting frame on top of the adjusting rings to support a lid at an elevation substantially level with the surrounding pavement. The casting frame is preferably sealed to the uppermost adjusting ring to preclude or minimize water flow into the manhole.
One problem with existing manholes is that many were made long ago, and then oftentimes were made of brick. Due to the old age of the manholes, as well as the materials used to make them, many manholes have begun to deteriorate or have damaged areas. The damaged areas create weak spots, which may allow water to infiltrate the sewer system and also lead to the eventual collapse of the manhole.
Methods exist for repairing the walls of manholes. One such method involves the use of a cured-in-place (CIP) liner with a polymer coating on its interior surface and a bladder to repair the manhole wall. The liner and bladder are placed in the manhole, and the bladder is expanded to press the liner against the manhole wall. The liner is impregnated with a resin and applied to the wall to create a new interior wall of the manhole. One problem with existing methods is the size of the liner used to line the wall of the manhole. The methods call for the use of a CIP liner and bladder having a diameter approximately equal to the smallest diameter of the manhole, with the liner being capable of stretching circumferentially to press against the manhole wall so to prevent the liner from wrinkling. However, some manholes require that the liner stretch up to and exceeding 150% of its unstretched diameter. This can cause the liners to rip, tear or be too thin, leaving the manhole wall not fully repaired.
Additionally, because the liners include an interior coating impervious to a resinous material, the liners cannot fold over themselves or bunch up because the liner wall would be formed with intermediate layers of material impervious to resin causing the liner to not be homogeneous across its thickness.
Accordingly, there is a need in the art for an improved method and means that overcomes the problem of a liner tearing while stretching circumferentially to press against the wall of a manhole.
BRIEF SUMMARY OF THE INVENTION
It is therefore a principal object, feature, or advantage of the present invention to provide an improved method and means for lining a manhole which improves over or solves the deficiencies in the art.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole wall that allows a liner to fold over itself and to bunch up while still producing a smooth interior wall.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole wall wherein the diameter of the liner is sized to be larger than the smallest diameter of the manhole.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole wall wherein the diameter of the liner is sized to be substantially equal to a largest diameter of the manhole.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole that uses a liner to transport a resinous material capable of curing and hardening into a manhole.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole that uses a bladder capable of stretching circumferentially to press the liner against the wall of the manhole.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole that uses a liner for containing a resinous material capable of curing and hardening.
Another object, feature, or advantage of the present invention is to provide an improved method and means for lining a manhole that can be used in manholes having varying diameters along the height of the manhole.
These and/or other objects, features, and advantages of the present invention will be apparent to those skilled in the art. The present invention is not to be limited to or by these objects, features and advantages, and no single embodiment need exhibit every object, feature, and advantage.
According to one aspect of the present invention, a method of lining a manhole having varying diameters along its height is provided. The method includes taking a manhole liner having a tubular shape and an unstretched diameter larger than a smallest diameter of the manhole. The liner is impregnated with a resinous material capable of curing and hardening. The liner is positioned in the manhole, and a bladder is inserted into the liner. The bladder is then expanded to press the liner against the wall of the manhole, with the liner folding on itself along a portion of the liner. The resinous material is allowed to cure and harden to produce a smooth finished surface, including along the portion of the liner folded on itself. Finally, the bladder is removed from the manhole.
According to another aspect of the present invention, a method of lining a manhole having varying diameters along the height of the manhole and having a largest diameter near the bottom of the manhole and a smallest diameter near the top of the manhole is provided. The method includes taking a manhole liner having a diameter substantially equal to the largest diameter of the manhole. The liner is impregnated with a resinous material capable of curing and hardening, and then positioned in the manhole. An inflatable bladder capable of stretching circumferentially is inserted into the liner. Next, the bladder is inflated to circumferentially stretch the bladder to press the manhole liner into contact with the wall of the manhole. The liner is folded over itself along an upper portion of the manhole. The resinous material is allowed to cure and harden against a substantially smooth surface of the bladder, and then the bladder is removed from the manhole.
According to yet another aspect of the present invention, a liner assembly for lining a manhole having varying diameters along the height of the manhole, with the largest diameter near the bottom of the manhole and the smallest diameter near the top of the manhole, is provided. The liner assembly includes a bladder and a manhole liner. The bladder comprises a first end, and opposite second end, and a bladder body there between, wherein the bladder body has a diameter smaller than or equal to the smallest diameter of the manhole. The bladder is also capable of stretching circumferentially. The manhole liner comprises a manhole liner body along its height, with the manhole liner body having a diameter substantially equal to the largest diameter of the manhole. Additionally, the manhole liner is impregnated with a resinous material capable of curing and hardening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an exemplary structure of a manhole.
FIG. 2 is a sectional view of the liner assembly of the present invention positioned in a manhole.
FIG. 3 is a top sectional view of the manhole of FIG. 2 according to line 3 - 3 of FIG. 2 .
FIG. 4 is a view similar to FIG. 2 showing the bladder fully inflated in the manhole.
FIG. 5 is a sectional view according to line 5 - 5 of FIG. 4 .
FIG. 6 is a sectional view of the repaired manhole after the bladder has been removed.
FIG. 7 is a sectional view according to line 7 - 7 of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a sectional view of an exemplary structure of a manhole 10 . The manhole 10 includes a bottom floor 12 , a barrel 16 above the bottom floor 12 , a cone 18 supported by the barrel 16 , and a plurality of adjusting rings 20 supported by the cone 18 . A casting frame 22 resides upon the upper most ring 20 and supports a lid 26 . The casting frame 22 is normally sealed to the top ring 20 . It is understood that one or more rings 20 may be used to adjust the height of the manhole 10 such that the lid 26 is substantially at the level of the pavement 66 surrounding the manhole 10 . Also, while FIG. 1 shows the cone 18 to have a concentric shape, it is understood that an eccentric cone can be utilized such that the manhole 10 has an asymmetrical cross-sectional appearance. FIG. 1 also shows an optional run through 14 in the bottom floor 12 . While each manhole generally has unique size and shape, it is generally understood that the basic construction of the manhole 10 is similar in all manholes. Although manholes comprise varying diameters D 1 , D 2 , D 3 , and D 4 along the height of the manholes, the manholes generally are narrower at the top section, or chimney, than at the bottom section. Additionally, bricks 72 generally form the wall 24 of manholes.
FIG. 2 is a sectional view of the liner assembly 30 of the present invention positioned in a manhole 10 . The liner assembly 30 includes a bladder 32 , a manhole liner 42 , and a base 68 . The bladder 32 comprises a first end 34 attached to the base 68 near the opening 28 of the manhole 10 , a second end 36 positioned at the bottom 58 of the manhole, and a bladder body 38 there between. The first end 34 of the bladder 32 may be attached to the base 68 outside of the manhole 10 as well. The diameter 40 of the bladder 32 is preferably less than or equal to the smallest diameter D 1 of the manhole 10 . However, the bladder body 38 is stretchable such that it is able to press against a wall 24 of the manhole 10 when expanded. The manhole liner 42 is attached at the opening 28 of the manhole, and comprises a manhole liner body 44 that at least partially surrounds the bladder body 38 in the manhole 10 .
The manhole liner body 44 is comprised of lining material substantially free of coating or intermediate layers of material impervious to the resinous material 48 . The resinous material 48 may be a thermoset resin, which saturates the liner and cures and hardens quicker in the presence of heat. However, it should be appreciated that other resinous materials may be used, on the condition that they are able to cure and harden. The manhole liner 42 is essentially a transport device, such that the resinous material 48 forms the structural properties of the liner when cured.
The diameter 46 of the manhole liner 42 in one preferred form is sized substantially equal to the largest diameter D 1 of the manhole 10 . Therefore, the manhole liner 42 does not need to be stretchable. After the manhole liner 42 has been impregnated with a resinous material 48 , the manhole liner 42 is positioned in the manhole 10 . The bladder 32 is then inserted into the manhole liner 42 . FIG. 3 is a top sectional view of the manhole 10 of FIG. 2 according to line 3 - 3 of FIG. 2 . FIG. 3 shows the bladder 32 and the manhole liner 42 positioned in the manhole 10 . As is seen in FIG. 3 , the diameter 40 of the bladder 32 is less than the diameter 46 of the manhole liner 42 . As is also shown in FIG. 3 , the original diameter 46 of the manhole liner 42 is substantially greater than the diameter D 3 of the manhole 10 at the adjusting rings 20 . Because the diameter 46 of the manhole liner 42 is greater than the diameter D 3 of the adjusting rings 20 , the manhole liner will fold over itself and bunch up to fit within the top section 60 of the manhole 10 .
In another preferred form, the diameter 46 of the manhole liner 42 is sized larger than the smallest diameter of the manhole 10 . Here, the manhole liner will again fold over on itself and bunch up to fit the smaller diameter portions of the manhole 10 .
FIG. 4 is a sectional view similar to FIG. 2 showing bladder 32 fully inflated in the manhole 10 . The bladder 32 is inflated with fluid pressure (not shown), such as air, introduced to the cavity 70 of the bladder body 38 . The increased pressure causes the stretchable bladder body 38 to expand circumferentially towards the wall 24 of the manhole 10 . The expanded bladder will press the manhole liner 42 against the wall 24 of the manhole 10 . This will create a layer 64 of resinous material 48 between the manhole liner 42 and the bladder body 38 . Because the bladder 32 has stretched circumferentially against the manhole liner 42 , the bladder body 38 will have a smooth surface abutting the layer 64 of resinous material 48 . This ensures that the resulting, manhole wall 24 will be smooth.
FIG. 5 shows a top sectional view of the manhole 10 of FIG. 4 according to the line 5 - 5 of FIG. 4 . FIG. 5 is a sectional view of the manhole 10 near the top section 60 of the manhole 10 , where the diameter D 3 of the manhole is substantially smaller than the diameter D 1 of the bottom 58 of the manhole 10 . Because the manhole liner 42 has been sized substantially equal to the diameter D 1 of the larger section of the manhole 10 , there will be excess manhole liner body 44 at this upper section. The excess manhole liner body 44 will fold over itself and bunch up to create folds 52 in the liner. However, because the manhole liner 42 does not contain a resin impermeable coating, the folds 52 will compress and resinous material 48 will form a manhole liner 42 in the same way as in the bottom section, where the manhole liner 42 is a single layer. The compression creates a layer 62 of resinous material 48 between the manhole liner 42 and the bladder 32 . The thickness of the layer 62 of resinous material may vary according to the number of folds 52 or bunches in the manhole liner 42 . However, because the bladder 32 was stretched to press the manhole liner 42 against the wall 24 of the manhole 10 , the bladder 32 will have a smooth surface 56 pressed against the varying layers of resinous material 48 . This will result in the resinous material having a smooth interior surface. Because the folds 52 contain two or more layers of manhole liner 42 , the resinous material 48 will cure and harden to produce a thicker wall 24 of the manhole 10 at the top section 60 of the manhole. However, because the top section 60 , including the cone 18 and adjusting rings 20 (the chimney), of the manhole 10 undergoes the most stress and usually contains the most damage, the resulting thicker wall 24 will be stronger to help resist cracking due to freezing and thawing.
FIG. 6 is a sectional view of the manhole 10 after the resinous material 48 has cured and hardened and the bladder 32 has been removed from the manhole 10 . The bladder 32 may be removed by deflating the fluid from the cavity 70 , and then by pulling a rope (not shown connected to the second end 36 of the bladder 32 . Pulling the bladder 32 out by the bottom first causes the bladder 32 to peel away from the cured resinous material 48 . Although peeling the bladder 32 requires the least amount of effort, it should be appreciated that the bladder 32 may also be pulled straight out of the manhole 10 from the first end 34 of the bladder 32 as well. After the manhole lid 26 is replaced on the casting frame 22 of the manhole, what remains is a manhole 10 having a repaired and structurally renewed wall 24 . As is shown in FIG. 6 , the manhole liner 42 has compressed the impregnated resinous material 48 from the manhole liner body 44 , creating a cured resinous material layer 62 around the interior periphery of the manhole 10 . As stated above, the layer 62 will be thicker in the top section 60 , or the chimney, of the manhole 10 because the manhole liner will have folded over itself. The thicker layer aids the section most affected by the elements, however. The folds 52 will occur in areas of the manhole 10 having a diameter less than the largest diameter D 1 of the manhole 10 .
FIG. 7 is a top sectional view of the manhole 10 of FIG. 6 according to the line 7 - 7 of FIG. 6 . FIG. 7 shows that although the manhole liner 42 folded over itself, the manhole liner 42 was compressed against the smooth outer surface 56 of the bladder 32 , such that the interior periphery of the resinous material 48 cured into a smooth finish 50 . At the upper section of the manhole, the folds 52 of the manhole liner 42 will cause the cured resinous layer 62 to be thicker than at the bottom of the manhole 10 . However, because the bladder 32 is pressed against the manhole liner 42 with even pressure, the layer 62 of resinous material 48 will be substantially equal at a given height around the interior of the manhole 10 . The resinous material 48 will migrate from the liner to fill low areas of the liner, formed due to the folds, to create a resinous surface that is smooth about the interior periphery of the manhole 10 . The smooth finish 50 of the cured resinous material 48 allows the manhole to be used as it had previously before it required repair.
The invention has been shown and described above with reference to preferred embodiments, and it is understood that modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. The invention is only to be limited by claims appended hereto. | A manhole liner and a method of using the same are provided. The manhole liner is sized substantially equally to the largest diameter of the manhole, so that the liner does not have to stretch to be pressed against the manhole wall. Additionally, the liner is impregnated with a resinous material capable of curing and hardening. A bladder, preferably stretchable circumferentially and having a diameter less than the smallest diameter of the manhole, is inserted into the liner. The bladder is expanded to press the liner against the wall of the manhole to dispense resinous material from the liner, while the liner is able to fold over itself in areas having a diameter less than the original diameter of the liner. Because the bladder stretches to produce a smooth outside surface, the resinous material will migrate to areas in the folds and will cure with a smooth interior surface. | 4 |
TECHNICAL FIELD
[0001] A security program has an ActiveX format for web browsers and application programs, and comprises a software security input window for preventing leakage of keyboard data without an additional hardware device but rather by using a conventional keyboard.
[0002] Therefore, the present invention protects keyboard data on the web browsers or application programs.
BACKGROUND OF THE INVENTION
[0003] (a) Field of the Invention
[0004] The present invention relates to an apparatus and a method for protecting keyboard data inputted by a user. More specifically, the present invention relates to an apparatus and a method for preventing leakage of the keyboard data using a security program.
[0005] (b) Description of the Related Art
[0006] Conventional techniques of keyboard data security on the Internet include a product “Kis” released by Safetek (www.esafetek.com) in January 2001, and keyboard data input means (or methods) such as a Java-based virtual keyboard other than a conventional keyboard system. However, since the former protects keyboard data on a hardware basis, it requires an additional device, and it is accordingly difficult to be applied to a general-purpose service such as the Internet, and the latter, that is, the security using the keyboard data input means other than conventional keyboard is not greatly used because of users' lack of skill and the inconvenience involved. Hence, even though it is urgently required to secure keyboard data comprising important personal information on the Internet, no general-purpose products have been provided to the market.
[0007] According to the present invention, the input data by conventional keyboard are securely processed.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to prevent keyboard data leakages from hacking when a user inputs personal information, writes electronic mail, or produces a document on the Internet or a network system.
[0009] In order to perform keyboard data security, first, when a scan code, which is caused by user key input, is transmitted to a keyboard device driver from a keyboard hardware, leakage of the scan code remaining at the I/O port 60 H must be prevented. However, since general application programs may not properly control the leakage because of their hardware properties and the Windows properties, a virtual device driver (V×D) accessible to Ring 0 is to be used to prevent the above-noted leakage.
[0010] Second, while the keyboard device driver converts the scan code into keyboard data and transmits the same to a system message queue, the converted keyboard data must be not leaked by external programs including API hooking and message hooking. However, since this process may not be protected through the Windows' default operating system (USER.EXE) as general methods, another keyboard entry method that does not use the Windows' default system should be supported.
[0011] Third, data leakage during the process of transmitting the keyboard data to a desired application program must be prevented. Hackers may hook or monitor the APIs or messages used by the application programs to leak the keyboard data. Therefore, a technique for securely transmitting the keyboard data to the application program is to be created.
[0012] In order to use the keyboard data on the web browser, first, it is needed for a security input window to be described using HTML documents supported by the web browser. Since the security input window does not follow the Window's default keyboard operating system, it is to be realized through a specific method to be in cooperation with the web browser.
[0013] Second, it is required to support low level tasks including communication with a virtual device driver VD on the web browser, and controlling hardware because the security input window according to the present invention uses a security keyboard driver, and directly controls the hardware keyboard to realize the security input window.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention:
[0015] FIG. 1 shows a whole configuration of a keyboard data security system according to a preferred embodiment of the present invention;
[0016] FIG. 2 shows a keyboard data flowchart of a security input window according to a preferred embodiment of the present invention;
[0017] FIG. 3 shows a data flowchart between a security keyboard driver and the ActiveX according to a preferred embodiment of the present invention;
[0018] FIG. 4 shows a web browser to which a security input window is applied according to a preferred embodiment of the present invention; and
[0019] FIG. 5 shows an exemplified HTML source to which a security input window is applied according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In the following detailed description, only the preferred embodiment of the invention has been shown and described, simply by way of illustration of the best mode contemplated by the inventor(s) of carrying out the invention. As will be realized, the invention is capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not restrictive.
[0021] The basic operation principle according to a preferred embodiment of the present invention on the web browsers is to not use a Microsoft Windows standard keyboard process, but rather to use a security keyboard driver and a security input window to securely transmit the keyboard data input by the user to a web browser. Also, the keyboard security of the present invention prevents the user's key input data from being stolen by a hacker. The user's key input data stored (more accurately, latched) in a buffer of the keyboard hardware are immediately modified. In the present invention, the keyboard hardware means a keyboard controller; however, it can be a device to include a data latch unit for temporally storing the user's key input data, which are usually stored as a scan code therein. In the computer system, the user's key input data are transferred to a CPU via the latch unit of an 110 port which is provided for the keyboard controller, such as a controller 8255 , (hereinafter, referred to as “keyboard hardware”).
[0022] FIG. 1 shows a whole configuration of a keyboard data security system, applied to a web browser, according to a preferred embodiment of the present invention.
[0023] First, a conventional keyboard processing of Microsoft Windows will be described. Electrical signals generated from a keyboard are provided to a keyboard hardware 101 of the motherboard, they are represented in scan codes, and they are provided to a virtual keyboard driver (VKD) 102 . The keyboard driver is used as a virtual driver in Windows 98; however, this may be another keyboard driver in other operating systems. The scan codes that are different from each other depending on the keyboard type are converted by the VKD 102 into a keyboard message used as the standard of the operating system. The keyboard messages stored in a system message queue 103 are transmitted to a virtual machine (VM) currently activated by USER.EXE which is a Ring 3 component of the operating system. The keyboard data stored in the VM are transmitted to a web browser 105 through a thread message queue 103 to perform a key input task. Finally, the keyboard data stored in the VM are transmitted to a web server 106 through the web browser 105 .
[0024] However, the key input task of the security input window according to a preferred embodiment of the present invention is realized in such a manner that a security keyboard driver, differing from the above-noted conventional keyboard processing, is driven.
[0025] According to the principle of the key input security task in a security input window, electrical signals generated from keyboard are provided to the keyboard hardware 101 of the motherboard, they are represented in scan codes, and they are provided to a virtual keyboard driver (VKD) 102 . After this, the virtual keyboard driver 102 calls VKD_Filter_Keyboard_Input that represents a hooking function (a user redefinition function) for user-defined key management. When a carry flag is set and returned from the hooking function called by the virtual keyboard driver 102 , the virtual keyboard driver 102 ignores a keyboard message and aborts subsequent keyboard message processing. The hooking function in the security keyboard driver stores the keyboard data in its queue, sets a carry, and returns the carry. Therefore, the keyboard message is not transmitted to a system message queue, a thread message queue, and a web browser, thereby preventing leakage of the keyboard data through message hooking. In this instance, the hooking function is provided to and managed by a security keyboard driver.
[0026] The security keyboard driver redefines the VKD_Filter_Keyboard_Input to prevent message hooking. However, the scan code remains in the keyboard hardware of the motherboard after the above-noted task. Scan code trace data may not be erased through a general method because of properties of the keyboard hardware. Hence, the keyboard hardware is controlled so as to erase the scan code trace data remaining in the keyboard hardware.
[0027] As to the method for erasing the trace data, when the hooking function is executed, VKD_Filter_Keyboard_Input of the security keyboard driver is called and a general control command (keyboard enable signal [F4H]) is issued and output to the keyboard hardware through the port 60 H. The control command, such as the keyboard enable signal [F4H], is a control signal that does not have an effect on the user's key input and the control signal can be selected from instructions to make meaningless data issued by the keyboard hardware, a CPU or other devices incorporated in the computer system. The keyboard data stored in the buffer are modified into the meaningless data under the control of the control command. Accordingly, since the key input data stored in the output buffer are modified immediately after the previously input data has been processed, the user's key input data are securely protected. Actually, since the key input data stored in the output buffer is not modified or erased directly, in the present invention, the modification is carried out by inputting again into the buffer the newly produced meaningless data regardless of the user's key input data. When receiving the control command from a CPU, the keyboard hardware is initialized itself with enabling the keyboard and outputs an acknowledgement (FAh) for the initialization to the CPU in response to the control command, and then erases the keyboard data stored in the output buffer of the port 60 H. In this process, the keyboard data stored in the output buffer of the port 60 H of the keyboard hardware are erased, the trace data of the port 60 H are changed to another value FAh, and accordingly, the scan code trace data are erased. By using this process, keyboard data hacking using a keyboard port is prevented. As a result, the keyboard data remaining in the output buffer of the keyboard hardware, more particularly in an output buffer (port 60 H) of the keyboard hardware, is modified into the acknowledgement (FAh) which is different from and regardless of the previously stored keyboard data.
[0028] For example, the keyboard hardware can modify the keyboard data stored in the buffer therein in response to the control command from a CPU, by alternating the keyboard data into other data and erasing them. Since the alternated data means specific data which can be the acknowledgement signal from the keyboard hardware, as set forth above, or specific data. In case of the specific data, they can come from the CPU together with the control command when the security keyboard driver is driven. Alternatively, the data to be modified can individually come from the CPU, the keyboard hardware, itself, or other devices if they are provided to the output buffer in the keyboard hardware in response to the control command. Also, it is possible to use an echo signal, as a response signal to the control command, which is issued in the keyboard hardware itself after the keyboard data are outputted. As to the method for transmitting the keyboard data stored in the keyboard data queue of the security keyboard driver to the security input window 110 having the ActiveX format, states of the queue of the security keyboard driver are periodically monitored by the security input window to receive the stored keyboard data. When receiving the keyboard data, the security input window converts the keyboard data of a scan code format into characters to store them, and displays them to a screen for the user to check input states.
[0029] When the user inputs data in the security input window, and presses one of a transmit button and a check button to go to a next task, the web browser 112 refers to data properties 111 of the security input window through scripts to proceed to perform tasks assigned by the scripts.
[0030] FIG. 2 shows a flowchart for interface and management between a virtual keyboard driver and a security keyboard driver. When a user presses a keyboard button, the keyboard hardware receives keyboard data from the keyboard to generate a keyboard interrupt and call a virtual keyboard driver in step S 201 . The called virtual keyboard driver reads a value of the port 60 H storing the keyboard data, stores it in a predetermined register, and calls a hooking function S 210 of VKD_Filter_Keyboard_Input. The hooking function S 210 representing a function that the security keyboard driver has, determines whether the security keyboard driver is activated or not S 204 , and the hooking function S 210 is terminated when the security keyboard driver is not activated. It also erases the keyboard data traces of the keyboard port 60 H using the above-noted method S 205 when the security keyboard driver is activated and stores the keyboard data in its queue S 206 . It then assigns a carry flag S 207 so that the virtual keyboard driver may not use the keyboard data, and it is terminated.
[0031] When calling the hooking function, the virtual keyboard driver checks the carry flag to perform the existing virtual keyboard driver job or ignore the input keyboard data S 208 and S 209 .
[0032] FIG. 3 shows a flowchart for processing keyboard data through interface between a security input window and a security keyboard driver. The security input window uses a timer to periodically communicate (function DeviceloControl) with the security keyboard driver in step S 301 to receive security keyboard data in step S 303 . After receiving the security keyboard data based on the determination S 302 , the security input window displays or stores the security keyboard data S 304 .
[0033] FIG. 4 shows an exemplified web browser 405 to which a security input window 404 is applied, referring to HTML codes of FIG. 5 . Referring to FIG. 4 , when a user uses a keyboard 401 to input a web address in the security input window 404 of the browser 405 through the security driver 403 or the virtual keyboard driver 402 , and presses a button 406 , the user is linked to the corresponding web page.
[0034] FIG. 5 shows the security input window 501 represented in HTML code format and process of the keyboard data input to the security input window in the HTML format.
[0035] The description of the security input window in the HTML format is performed according to the ActiveX format, and the data reference of the security input window follows the ActiveX property format.
[0036] The security input window as shown in the subsequent example 502 is expressed as the OBJECT in the HTML codes.
[0000]
<OBJECT
classid=“clsid:C1BF8F0F-05BA-497C-AEDA-F377E0867B3C”
name=“akl1”
codebase=“http://localhost/AKLEditXControl.cab#version=1,0,89,9”
width=350
height=23
align=center
hspace=0
vspace=0
>
<param name=“Value” value=“www.yahoo.com”>
<param name=“Border” value=“2”>
<param name=“BorderLeftcolor” value=“0”>
<param name=“BorderRightcolor” value=“0”>
<param name=“BorderTopcolor” value=“0”>
<param name=“BorderBottomcolor” value=“0”>
<param name=“BorderStyle” value=“1”>
<param name=“Font”value=“MS Sans Serif”>
<param name=“Size” value=“56”>
</OBJECT>
REFERENCE DOCUMENT
[0000]
http://msdn.microsoft.com/workshoplauthor/dhtml/reference/objects/OBJECT.asp)
[0038] The next exemplar 501 describes a method for referring to the keyboard data input to the security input window in the HTML codes.
[0000]
<script language=“javascript”>
function geturl( ) {
var ak = http:// + akl1.value;
window.open(ak)
}
</script>
[0039] In the above codes, akll. value is called to refer to the data of the security input window.
[0040] 1. The preferred embodiment of the present invention protects the keyboard data input by a user on the Internet to increase reliability of Internet-related industries and activate the industries.
[0041] Internet tasks including Internet banking, Internet games, web mail, web contents, and security document composition basically require a user to use a keyboard. Leaked keyboard data may cause great confusion and damage to the Internet tasks of companies.
[0042] Therefore, the use of the security key input window prevents leakages of the keyboard data to improve reliability of Internet business and to activate the Internet business, and it will reduce direct loss and damage caused by the leakage of the keyboard data.
[0043] 2. The preferred embodiment does not handle malicious programs in the like manner of vaccine programs, but it copes with hacking, and hence, the preferred embodiment protects the user's keyboard data against new programs and undetected hacking programs.
[0044] 3. Hackers may not steal the keyboard data using existing hacking tools if they have no new hacking techniques, which reduces the hackers' fields of action.
[0045] 4. The preferred embodiment provides a software security system, and it recovers the security level through an immediate improvement when the security level of the system is lowered, thereby increasing the reliability of keyboard data security and obtaining Internet business related reliability.
[0046] While this 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 limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
[0047] The word ‘comprising’ and forms of the word ‘comprising’ as used in this descripting and in the claims does not limit the invention claimed to exclude any variants or additions. | Various embodiments for protecting keyboard data inputted by a user in a computer having a keyboard hardware are disclosed. According to one exemplary embodiment, a method for protecting keyboard data, where the keyboard hardware comprises an I/O port having an input buffer and an output buffer, includes: receiving scan code data based on keyboard data inputted by the user, wherein the scan code data are latched in the output buffer of the I/O port; executing an interrupt routine to fetch the scan code data from the output buffer to a CPU of the computer, wherein the latched scan code data remains in the output buffer after the latched scan code data are read from the output buffer; transmitting a control command to the keyboard hardware through the input buffer of the I/O port; and receiving from the keyboard hardware a response signal generated in response to the control command, wherein the keyboard hardware is configured to transmit the response signal to the output buffer of the I/O port. | 6 |
FIELD OF THE INVENTION
The present invention relates to a vibration pile driver for ramming and/or pulling ram material with at least four motor-driven eccentric agitators to each of which at least one eccentric mass with variable static moment is arranged, whereby the effective eccentric radius of the eccentric masses on the corresponding eccentric shaft can be adjusted and the adjustment of the eccentric masses can be effected synchronously and in the same direction.
BACKGROUND OF THE INVENTION
DE-OS 29 32 287 proposes a vibration pile driver for ramming and/or pulling of rammed bodies such as posts and piles, etc., with the drivers having at least two synchronous eccentric rotors each of which can be driven by at least one motor and one gear box, and each of which has at least two eccentric masses which can be driven around the same axis and adjusted angularly relative to each other, whereby the eccentric masses of each eccentric rotor are mounted on separate shafts arranged concentrically to each other, and whereby, for at least one of these shafts, an adjustment device is provided for displacing the phase position of one shaft relative to the other shaft. The phase adjustment device is integrated in part into the gear box. One of the shafts of the eccentric rotors takes the form of a hollow shaft supported on the other. The phase adjustment device is a part of a planetary gear system whose planet wheel, engaging an annular gear forming the sun wheel of the shaft to be rotated, forms the drive wheel of this shaft, whereby this shaft is adjustable relative to the other shaft along a circle concentric to the latter, in order to adjust the phase position. The planet wheel can be driven via a bypass gear, by a transmission gear which, at the same time serves to drive the other shaft of the eccentric rotors. The vibration pile drive is constructed in such a way that the gears engaging the planet wheel are supported at least partially by a bearing arranged between and connected to two swivel mounted levers. One swivel mounted lever can be swung around the axis of the two shafts of the one eccentric rotor which is adjustable relative to each other. The other swivel mounted lever can be swung around the axis parallel to the axis of the transmission drive shaft. The swivel action of one of the swivel mounted levers is continuously adjusted between two end positions. The planet wheel and the intermediate gear wheel of the bypass gear are each connected in bearings to one of the two swivel mounted levers. In the bearing assembly, these two gears are engaged by two intermediate gears arranged between them. The bearing positions of all of the gears define the corners of a trapezium. A cylinder and piston acts as an adjustment device, the piston rod of which is connected to a swivel mounted lever. The maximum arc described by the swivel mounted lever corresponds to a rotation of the rotor shaft through 180° relative to each other. The vibration pile driver is equipped with an indicator device showing the effective static moment thereby permitting the static moment of the vibration pile driver to be remotely controlled and continuously adjusted from zero to a maximum value during a ramming or pulling action.
The prior art device is extraordinarily complicated in construction. This may be the reason why it has, to date, not been possible for this design to be used in practice.
With the vibration pile drivers used in practice, there is a risk of resonance if the operating speed drops, so that uncontrollable vibrations can be transmitted to nearby buildings and in the ground across a wide area of, for example, 50 to 200 meters. In order to make resonance-free vibration work possible, a high reserve of performance must always be provided so that a strong centrifugal force and a constant operating speed is always available even with the heavy ram material and in heavy soil conditions. This is very important when working in residential areas, near railway installations and other buildings sensitive to vibration.
A further cause of resonance vibrations from hydraulic vibration pile drivers is the long start-up and breaking times of the eccentric masses. This enormous disadvantage has its origins in the physics and of the design of the equipment and can only be eliminated conditionally at the expense of rapid wear of the hydraulic drive motors. When the vibration driver is started up, the aperiodic vibration must be generated immediately at full power. This means high operating pressure and long run-up to the nominal speed of the eccentric masses. As a rule, a resonance range is run through linearly relatively slowly, with the result that, during this period, resonance vibrations can build up and affect the ground for a relatively long time. The same effect occurs during deceleration of the eccentric masses, when the resonance range runs through the time determined by the design. The result of reducing the start-up and braking time is that the inertia of the rotating masses (eccentrics, shafts, couplings) could cavitate the hydraulic motors which would fail after a short time.
DE-PS 35 15 690 proposes a vibration pile drive with eccentric adjustment for ramming and/or pulling ram material, with at least two eccentric motors supported in parallel bearings, and driven by at least one motor and gear box synchronously and oppositely. Each of these eccentric motors comprises two eccentric masses mounted on concentrically arranged shafts synchronously driven and adjustable angularly relative to each other by an adjustment device. Each of the first eccentric masses of both eccentric motors can be driven in opposite directions via a first gear train and each of the second eccentric masses can be driven in opposite directions by a second gear train. The eccentric motor is constructed in the form of a rotary piston adjustment device, in which both eccentric masses are arranged in a cylindrical closed housing and the first eccentric mass forms a radial web permanently attached to the housing, while the second eccentric mass forms the radial blade which can be rotated within limits in the housing and is sealed off from the housing and the web. Hydraulic fluid is applied to each of the two chambers formed between the blade and the web, alternately through their own control conduit. Essentially each eccentric mass is, in cross section sectored, with each eccentric mass extending through a quarter circle. The eccentric mass forming the blades is connected with an internal shaft, in which axial holes are provided for the hydraulic fluid, whereby the control conduits are connected to the ends of the shaft and are sealed off from the shaft by shaft seals. The design of the second eccentric rotor is similar to that of the first eccentric rotor, except for the fact that, with the second eccentric rotor, the two chambers are connected to each other by a connection hole and two control conduits are eliminated. The hydraulic motors grip the shafts of the second eccentric rotor. The angle of the eccentric masses can be adjusted relative to the eccentric rotors both during operation and when stationary. This is achieved, for example, by introducing hydraulic fluid into chambers via a valve and control conduits, while, at the same time, hydraulic fluid emerges from another chamber via a control line. The closer the two eccentric masses approach each other, the greater the static moment, which reaches its maximum when the approach of the two eccentric masses is complete. Conversely, the two sectored eccentric masses can be adjusted in opposite directions by the corresponding introduction of hydraulic fluid. If they are arranged diametrically opposite to each other, the centrifugal force of the eccentric masses cancel each other out, and a minimum static moment is achieved. Between these two extreme positions, any intermediate position is possible via a valve, both during operation and while the vibration pile driver is stationary. This opens the possibility of running up these vibration pile drivers without an activated eccentric mass through the critical range and of switching in or activating the eccentric mass or the eccentric masses once the critical speed range (resonance range) has been passed and, when reducing the speed, of again switching out or neutralizing the eccentric masses above the critical resonance range. The disadvantage with this prior art construction is that the relatively complicated construction requires forced synchronization of the eccentric actuators through a reducing gear.
DE-OS 41 39 798 proposes a vibration pile drive in which each eccentric shaft has a hollow rotating piston which is provided with an adjustable eccentric mass. The longitudinal axis of each piston is arranged orthogonally to the longitudinal rotational axis of the corresponding eccentric shaft. Each of the pistons takes the form of a cylinder in which the corresponding cylindrical eccentric mass is arranged so as to the axially displaceable. Pressure transmitting conduits are connected to the cylinders through which pressure media can be applied to cylinder compartments working in the same direction, by partial flow currents, whose basic parameters (flow pressure, flow volume and flow speed) are equally dimensioned. These vibration pile drivers are aimed at achieving a relatively simply construction with which nevertheless the static moment required at each point can be achieved in order to avoid damaging resonance vibrations. In addition, the aim is to be able to adapt to existing operating conditions are required.
At the start of a ramming operation, for example, light ramming work, or at the end of a pulling operation, the static moment is reduced, i.e. reduced centrifugal force at a constant speed, whereby it is perfectly possible to set the centrifugal force to zero. This results in considerably less vibration. Adaptation to the progress of the ramming operation is easily possible by adjusting the eccentric forces.
For heavy ramming operations, if power requirements become so large that the speed drops, the speed can be maintained by reducing the static moment so that disturbing vibrations in the ground and the surrounding area can be avoided. This is very important, for example, when working in residential areas, near to railway installations and other vibration sensitive buildings. Under certain circumstances, the fall off of speed on vibrators with no static moment or centrifugal force adjustment facility during operation, ground vibration can become so great that ramming or pulling operations can no longer be carried out without the risk of building cracking or being similarly damaged.
During the raising and lowering of vibration pile drivers, the eccentric masses are practically switched out, i.e. they are no longer effective as eccentric masses. This means that considerably lower resonance force is applied to the boom, which resonance forces could otherwise prematurely destroy the boom. By this means, efficient operations is achieved which includes a saving in energy. Operationally unfavorable combinations of speed and static moments are therefore avoidable.
As the eccentric masses are attached to the agitator shafts, special bearings, machine parts, gears and complicated planet gears no longer need to be used. This results in a significantly more simple design and a compact and relatively light construction. As a consequence, the entire vibration ram applies only relatively little load to the ram material, avoiding the tendency to buckle and the center of gravity can be favorably located.
The agitator shafts are fashioned as hollow bodies whereby, in each of the hollow shafts, there is at least one piston axially displaceable within the hollow shaft. The corresponding cylindrical compartments in the hollow shafts are each connected to the same pressure media conduit so that the pistons can be adjusted synchronously and in the same direction by pressure medium pressure whose basic parameters (flow pressure, flow volume and flow speed) are equal. For example, pistons representing the eccentric masses can be loaded in their neutral position (zero position) by pressure from a pressure medium, in particular, hydraulic pressure. By correspondingly removing the pressure medium pressure, the pistons can be adjusted continuously to the particular position required by the centrifugal force of the rotating hollow shafts, whereby the eccentric masses are continuously adjustable from their neutral position to their maximum position. By this means, any rotational speed or any particular position can be related to the eccentric masses thus making corresponding adjustments of the static moments possible.
In the zero position (neutral position), the pistons can be located on, or almost on, the rotational axis of the agitator, so that no, or only a minimal, eccentric force and thus no centrifugal force, can develop. As soon as the pistons move away from a neutral position, a specific static moment, depending upon the position of the piston, and a specific centrifugal force depending upon the speed develop. When the piston reaches its end position, the maximum static moment and maximum centrifugal force are reached.
The adjustment can actually be effected hydraulically, pneumatically or electro-mechanically. However, in practice, hydraulic adjustment will probably be given preference.
SUMMARY OF THE INVENTION
The invention is aimed at achieving the objective of constructing a vibration pile drive of the aforementioned type in such a manner that, with simple and reliable design methods, each of the eccentric masses of the vibration pile driver can be angularly and continuously adjusted relative to the drive shaft to which it is assigned.
In accordance with the present invention, a vibration pile driver for ramming and/or pulling ram goods includes at least four motor driven eccentric agitators to each of which at least one eccentric mass is arranged, with adjustable static moment. The eccentric masses are arranged on a corresponding eccentric shaft and are adjusted relative to an effective eccentric radius. The adjustment of the eccentric masses can be effected synchronously and in the same direction. The eccentric masses are forcibly coupled in pairs by a flexible pull element, for example, a serrated belt, with the eccentric mass being continuously adjustable in both directions.
By virtue of the above noted features of the present invention, in a so-called four-shaft vibration pile driver, the eccentrics of each of two pairs of hydraulically or electrically driven vibration pile drivers work in opposition and, in accordance with the invention, the eccentric masses of the eccentric agitators can be coupled together by a pull element, for example, by a serrated tooth belt. In this manner, by suitably arranging the belt path, the eccentric masses can be continuously and very finely adjusted in both directions even during operation. There is no longer any danger of resonance as the eccentric masses are not activated until, for example, the maximum speed has been reached or the critical speed has been passed. It is also possible to adapt the centrifugal force to the ground conditions by continuous adjustment of the corresponding rotational angle of the eccentric masses.
By use of, for example, serrated tooth belts, a simple robust construction is achieved, as gears, stepping motors and similar elements are no longer required. In four-shaft vibration pile drives, it is not possible to neutralize the eccentrics.
According to the present invention, the adjustment of each pull element can be effected by at least one adjustment roller.
The adjustment rollers of the present invention may be adjusted orthogonally to a straight line connecting the center point of shafts of the eccentric masses.
The flexible pull element, fashioned as serrated belts, may, in accordance with the present invention, be looped around the toothed eccentric masses and around each of the toothed guide rollers arranged off center between the shafts of the eccentric masses.
According to the present invention, on each side of a line of symmetry drawn through a center point of a hole of a suspension bearing, four eccentric agitators are arranged in pairs, with guide rollers of the eccentric agitators being continuously adjusted from a neutral to an activated position by jointed adjustment rods by an angularly adjustable adjustment device, with the agitators being adapted to be arrested in each required position.
In accordance with still further features of the present invention, each of the shafts of the eccentric masses is assigned a separate drive motor and all of the drive motors are connected to the same power source.
Advantageously, the separate drive motors may be hydraulic drive motors, with the same power source being a hydraulic pressure conduit without flow splitters or volume regulators being interposed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a vibration pile driver having four shafts constructed in accordance with the present invention, with eccentric masses in a neutral position;
FIG. 2 is a schematic view of a vibration pile driver of FIG. 1, with eccentric masses activated;
FIG. 3 is a schematic view of a further embodiment of a four shaft vibration pile driver of the present invention with eccentric masses in a neutral position;
FIG. 4 is a schematic view of the vibration pile driver of FIG. 3 with the eccentric masses activated;
FIG. 5 is a schematic view of an eight-shaft vibration pile driver constructed in accordance with the present invention with the eccentric masses in a neutral position; and
FIG. 6 is a schematic view of the vibration pile driver of FIG. 5 with the eccentric masses activated.
DETAILED DESCRIPTION
In the drawing, a rigid vibrator cell 1 includes four shafts 2, 3 and 4, 5 arranged to rotate in bearings (not shown). Each of the shafts 2-5 is allocated to a separate electric or hydro-static drive with the drives being equal in size and power and running at the same speed. For example, in the case of the hydraulic drive, hydro-static motors can be arranged on each of the shafts 2, 3 and 4, 5. As shown in the drawings, the shafts are supported in the rigid vibration cell, spaced apart, and with their longitudinal axes of rotation running parallel to each other. A straight line, drawn through each of the centers of rotation of the shaft pairs, 2, 3 and 4, 5 extends orthogonally through each of the straight connecting lines 8 and 9 connecting the centers of rotation of two adjacent shafts 2, 4 and 3, 5. The connecting lines 8 and 9 also run parallel to each other. If the rigid vibrator cell 1 is set up on a rigid horizontal surface, the connection lines 6 and 7 run vertically, while the connecting lines 8 and 9 are horizontal. The pairs of shafts 2, 3 and 4, 5 rotate in opposite directions. The shafts 2, 3 are driven in the direction indicated by the arrow A and the shafts 4, 5 are driven in the direction indicated by the arrow B.
Each of the shafts 2, 3 and 4, 5 is assigned at least one eccentric mass 10, 11 and 12, 13. The eccentric masses 10, 11 and 12, 13 are arranged on the shafts 2, 3 and 4, 5 and are continuously adjustable both in the direction of the arrow A and in the direction of the arrow B through a rotational angle of at least 90°.
Adjustment rollers 14, 16 and guide rollers 15, 17 are provided, with the respective axes thereof extending parallel to the shafts 2, 3 and 4, 5. The adjustment rollers 14, 16 are arranged in a central zone between the eccentric masses 10, 11 and 12, 13, orthogonally to the connecting lines 6 and and can be adjustable within limits in a straight line in the directions designated by the arrows C and D in FIGS. 1 and 2.
The eccentric masses 10, 11 and 12, 13 are provided with teeth arranged around the circumference, which are not shown in the drawings. This also applies to the adjustment rollers 14 and 16 and to the guide rollers 15 and 17. The teeth of the eccentric masses 10, 11 and 12, 13 and the corresponding adjustment rollers 14, 16 and guide rollers 15, 17, engage one of the serrated belts 18 and 19 forming the continuous pull element or endless belt. As can be seen, the serrated belt is looped around the two eccentric masses 10, 11 and the guide roller 15 while the serrated belt 19 is looped around the two eccentric masses 12 and 13 as well as the guide roller 17 thereby resulting in the forcible synchronization of the eccentric masses 10, 11 and 12, 13.
Of course, more than four shafts with eccentric masses can be used, for example, six or eight of such shafts may be provided with each arranged in groups, in order to achieve a targeted striking and pulling action.
On start-up, the eccentric masses are in the neutral position shown in FIG. 1, that is, they generate no striking action. As a result, the four-shaft vibration pile driver can be run up to the required speed without harmful vibration or resonance being developed.
Next, the drive of the adjustment rollers 14, 16 is activated moving them into the position shown in FIG. 2 or into any other intermediate position required, and the adjustment rollers 14, 16 are arrested or locked in the intermediate or final position required. The adjustment travel of each of the guide rollers 14, 16 is equal in length. Furthermore, the adjustment of the guide rollers 14, 16 is synchronized and in the same direction.
This results in the forcibly synchronized eccentric masses, 10, 11 and 12, 13 being adjusted (rotated) in the circumferential direction via the respective serrated belts 18 and 19. FIG. 2 illustrates the maximum extent of rotation, at which the four-shaft vibration pile driver generates its maximum striking force. In this position, the eccentric masses 10, 11 and 12, 13 are rotated synchronously and in the same direction through 90° relative to FIG. 1. This can take place during the operation of the four-shaft vibration pile driver so that the centrifugal force can be run up or down to the power required in each case during operation in accordance with the existing operating conditions, for example, the ground conditions.
In the embodiment shown in FIGS. 3 and 4, the same reference numerals have been used for parts with identical functions as used for the embodiment in FIGS. 1 and 2. The eccentrics 10, 11 and 12 and 13 are in their neutral position in FIG. 3 and in FIG. 4 shown in their activated position rotated through 90°. Reference numerals 20-27 are used to designate fixed guide rollers.
Each of the pair of rollers 28, 29 and 30, 31 is respectively arranged on a straight line guide 32 and 33 and can be respectively adjusted simultaneously and synchronously in the directions of the arrows C and D. Synchronous adjustment of the two pairs of rollers 28, 29 and 30, 31 is effected mechanically or hydraulically by gears or pistons.
A suspension bearing 34 is individually and immovably connected in the rigid vibrator cell 1. The bearing 34 has a central hole 35 for connection with a cable or chain on which the vibration pile driver is suspended from a crane or similar device. As a rule, a suitable shock absorber is interposed in order to prevent harmful vibrations reaching the boom of the crane or a similar device.
In the embodiment of FIGS. 5 and 6, the same reference numerals have been used for parts with identical functions as used for the embodiments described hereinabove.
Four eccentric agitators are arranged in pairs and in the same horizontal and vertical planes on each side of a straight axis of symmetry 44 extending through the center of the hole 35. These agitators are equal in size and in performance and are driven at the same speed. The directions of rotation are indicated by the arrows A and B. For example, in the case of the hydraulic drive, hydro-static motors can also be used in this embodiment on each of the shafts 36, 37, 38 and 39 and on 40, 41, 42 and 43. As shown in FIGS. 5 and 6, four such shafts are arranged in pairs above and next to each other on each side of the axis of symmetry 44, and are located in the same vertical and horizontal planes, and are also supported in the rigid vibrator cell 1. Pairs of shafts 36, 37 and 38, 39 and shafts 40, 41 and 42, 43 are arranged equidistant from the axis of symmetry 44.
Eccentric masses 44, 45, 46, and 47, 48 as well as 49, 50 and 51, 52 are equal in size and assigned to the shafts 36 to 43. The straight connecting line, which runs through the center points of the shafts 36, 37 and 40, 41, on the one hand, and 38, 39 and 42, 43, on the other, extends, in each case, orthogonally to the axis of symmetry 44.
The guide rollers 28 and 29 as well as 30 and 31 are arranged on guides 32 and 33, respectively, and can be adjusted in a straight line within limits in the directions of the arrows C and D. For this purpose, the guide rollers 28, 29 and 30, 31 are each coupled to an adjustment rod 53, 54, respectively, by a joint or swivel mounting. At their other end, the adjustment rods 53 and 54 are connected to an adjustment device 55, again by a joint or swivel mounting, which is assigned to the adjustment spindle 56 which can be adjusted through approximately 90° by a motor drive (not shown) in the direction of the arrows E and F. FIG. 5 shows the eccentric masses 45 to 52 in a neutral position, while FIG. 6 shows the adjustment device 55 swiveled through 90° in the direction of the arrow E by the adjustment spindle 56. This results in the uniform (synchronous) adjustment of the eccentric masses 45-52 in the same direction on each side of the axis of symmetry 44, via the flexible pull elements 18 and 19 (belts, serrated belts, chains or the like) for this purpose, the eccentric masses 45-52 are provided with suitable gear teeth cut on the periphery in the event serrated belts are being used for the flexible pull elements 18 and 19. An adjustment in the direction of the arrow F by approximately 90° returns the eccentric masses 45-52 back to the neutral position (FIG. 5). All intermediate positions can, of course, also be adjusted during operation so that once the critical speed has been passed, the driving or pulling force of the vibration pile driver can be increased up to the maximum value or continuously reduced to a minimum value. Of course, the adjustment rods 53 and 55 can also be arrested or stopped in any required position through the adjustment device 55. An adjustment scale can be provided for this purpose on the vibration pile driver. The adjustment can also be effected by remote control.
In place of two pairs of eccentric agitators on each side of the axis of symmetry 44, six, eight or even a larger number of pairs of eccentric agitators can be arranged on each side of the axis of symmetry 44. These agitators can be designed so as to be continuously adjusted and set, at the same time and in the same direction, in other words, synchronously even during operation of the vibration pile driver. This will be determined by the particular operating conditions and required driving or pulling power of the vibration pile driver. | A vibration pile driver for ramming and/or pulling ram material in which eccentric masses are positively coupled in pairs by flexible draw elements and are adapted to be continuously adjusted and locked in opposite directions. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This new application is a continuationin-part application of U.S. patent application Ser. No. 10/321,721 filed on Dec. 18, 2002, now U.S. Pat. No. 6,883,490, which is a continuation of U.S. application Ser. No. 09/954,195 filed on Sep. 18, 2001, now abandoned, which is a continuation of U.S. application Ser. No. 09/501,788 filed on Feb. 11, 2000, now U.S. Pat. No. 6,289,868. These prior applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for improving fuel burners in furnaces by using a plasma ignition system.
2. Description of the Related Art
As described in applicant's prior applications listed above and incorporated herein by reference, there are numerous problems with the combustion process for diesel engines. None of the prior art references disclosed an apparatus that will allow for the initiation of combustion for all of the fuel as it is injected into the combustion chamber followed by the maintenance of the combustion process to its completion in the manner described therein.
Also, fuel burner technology for furnaces usually relies upon a simple electrical arc discharge ignition system, usually positioned to one side of the fuel spray coming out of the nozzle. In some cases the ignition system is as primitive as a simple pilot light for flame ignition.
Although these oil burner ignition systems are simple, reliable, and cheap they have absolutely no fuel treatment capability. This lack of point of use fuel treatment results in four serious limitations:
1. Less than optimal fuel efficiency as a result of incomplete combustion;
2. Pollutant emissions as evidenced by the production of oxides of nitrogen (NO x ), carbon monoxide (CO), hydrocarbons, and particulates (soot) that are observed in the exhaust output;
3. Unstable combustion when dealing with fuel that has been contaminated by water; and
4. Imposed limitations on the fuel oil weight used in a given burner design.
To date, a variety of methods have been employed to improve the efficiency of and reduce pollution from fuel oil burners used in furnaces and similar systems. Higher fuel pressures, smaller fuel nozzle orifice sizes, different fuel nozzle configurations, improved fuel/air mixing arrangements, fuel pre-heating, and improved heat exchanger systems have provided for improved fuel efficiency and some reduction in pollutant emissions.
None of these approaches has the effect of chemically altering the fuel on its molecular level.
As best understood, the present invention chemically alters the fuel in the combustion process directly at the fuel's point of use, changing the fuel's chemical structure right after it leaves the fuel oil burner's nozzle as it enters the combustion area. This enhances the fuel combustion process significantly. These benefits of the present invention are complimentary with and in addition to those realized by the previously mentioned methods currently in use.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide an apparatus and method for assuring the immediate and complete combustion of any hydrocarbon fuel sprayed into the combustion area of furnaces and similar systems.
It is a further object of the present invention to make it possible to easily retrofit this apparatus to existing furnaces and also to provide a method for assuring the complete combustion of any hydrocarbon fuels in the existing fuel burners.
An area of ionizing electrical energy, effectively an electrical catalyst, (for purposes of illustration, it is referred to as a “plasma ball” or “ring-of-fire”) is created inside the combustion area directly in front of the fuel nozzle. The placement of this plasma ball is critical in that all of the fuel must pass through the plasma ball as it enters the combustion area.
Plasma created between the electrodes of the plasma ball generator of the present invention may not be perfectly spherical in shape. The term “plasma ball” or “ball of plasma” as used herein, includes a spherical shaped plasma as well as other polygonal shapes, such as a partially flattened sphere or an elongated hemisphere. When the plasma discharge is operated in still air with the electrodes placed closely together the shape of the discharge, while being close to spherical to the naked eye, is more accurately an ellipsoid. When the plasma discharge is being put to work, the movement of air and fuel through the plasma ball distorts it further from the ellipsoid shape to a shape similar to a tee-pee with the pole ridges marking the electrode locations. As long as the plasma discharge is vigorous, the change in shape does not have a significant effect on the performance of the plasma.
Plasma is defined in the world of physics as a state of matter where the electrons that normally orbit the nucleus of an atom are instead dissociated from the nucleus. For the purposes of the present invention, it is unnecessary and inefficient to create pure plasma in which all of the electrons of all of the atoms are separated from all of the nuclei. The partial plasma created by the present invention strips off enough electrons to do what needs to be done for effective fuel treatment to take place.
These outer electrons are referred to as outer valence electrons. As best understood, these are the electrons that the “Plasma ball” created by the present invention is adept at removing. By having the correct shared outer electrons stripped away from the carbon atoms of the fuel molecules, these fuel molecules are broken down into shorter chain hydrocarbon fuel molecules such as, but not limited to methane, ethane, propane, butane, and pentane that are well known to burn much cleaner than almost all longer chain hydrocarbons.
This treatment of the fuel using the plasma ball ignition system also does other functions. It is believed that in addition to breaking down the fuel molecule into shorter chain hydrocarbons, it also puts an electrical charge onto each shorter chain hydrocarbon molecule. The effect of this electrical charge on the shorter chain hydrocarbon molecules is to increase its reactivity to oxygen dramatically. All that is needed for the shorter chain hydrocarbon molecules to ignite is for them to come into contact with oxygen.
The same molecular dissociation that breaks fuel oil molecules down also enables oil burners equipped with the present invention to deal with water contamination of the fuel with ease. When water mixed with the fuel passes through the “Plasma ball” it is believed to be electrolyzed into hydrogen and oxygen and then the hydrogen ignites and burns with the rest of the fuel without interfering with the overall combustion stability.
Both the chemistry of the fuel and the combustion process itself are completely changed by the “Plasma ball” point of use fuel treatment method and apparatus when utilized in a hydrocarbon fuel burner. It is believed to act as an electrical catalyst which greatly promotes the immediate and complete combustion of all of the fuel resulting in the following advantageous effects:
1) Greater fuel efficiency as a result of earlier completion of combustion thus allowing more time for heat transfer from the combustion gases to the heat exchanger wall.
2) Greater fuel efficiency than available from the present technology oil burners by burning completely those hydrocarbon components usually coming out of the exhaust flue as hydrocarbon emissions such as carbon monoxide, particulate matter, soot, and others.
3) Reduced hydrocarbon pollutant emissions as a direct result of complete combustion of all of the fuel.
4) The ability to greatly reduce pollutant emissions of oxides of nitrogen by making possible the much more aggressive utilization of exhaust gas recirculation without the loss of combustion efficiency.
5) The ability to maintain stable combustion when using fuels contaminated with water.
6) The ability to effectively and efficiently use heavier weight fuel oils that cost much less due to the present invention's ability to convert these lower quality fuels into much easier to combust compounds at the point of use.
The efficacy of the “Plasma ball” point of use fuel treatment and ignition system is evidenced by the empirical observations made during a series of side-by-side comparative tests. For this testing program, a Riello model 40F10 oil burner was retrofitted with the plasma ball point of use fuel treatment system and installed in a furnace heating a commercial building and compared to exactly the same furnace and oil burner setup next to each other under the same conditions at the same time. Fuel efficiency was improved on average 7.6% with over-all pollutant emissions reduced between 25 to 35%, depending on the specific pollutant. Earlier testing done on a home heating furnace with a retrofitted Beckett oil burner according to the present invention had the result of showing no detectable particulates and a carbon monoxide level below that which could be detected by the testing equipment being used.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will be clearly understood from the following description with respect to the preferred embodiment thereof when considered in conjunction with the accompanying drawings and diagrams, in which:
FIG. 1 is a cross sectional side view of the injector/igniter apparatus of the present invention installed in an engine cylinder head.
FIG. 2 is a cross sectional side view of the injector/igniter apparatus of the present invention installed in an engine cylinder head with fuel being injected into the combustion chamber.
FIG. 3A is an enlarged side view of the lower end of the injector/igniter apparatus that extends through the cylinder head.
FIG. 3B is an enlarged bottom view of the injector/igniter apparatus.
FIG. 3C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 3A .
FIG. 3D is an enlarged perspective view of the injector/igniter apparatus.
FIG. 4A is an enlarged side view of the injector/igniter apparatus with the Ring-of-Fire shown in operation.
FIG. 4B is an enlarged bottom view of the injector/igniter apparatus with the Ring-of-Fire shown in operation.
FIG. 4C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 4A .
FIG. 4D is an enlarged perspective view of the injector/igniter apparatus with the Ring-of-Fire shown in operation.
FIG. 5A is an enlarged side view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 5B is an enlarged bottom view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 5C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 5A with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 5D is an enlarged perspective view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 6A is an enlarged side view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 6B is an enlarged bottom view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 6C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 6A with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 6D is an enlarged perspective view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 7A is a cross sectional side view of the injector/igniter apparatus of the present invention.
FIG. 7B is a top view of the injector/igniter apparatus of the present invention.
FIG. 7C is a bottom view of the injector/igniter apparatus of the present invention.
FIG. 8A is a cross sectional side view of the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 8B is a top view of the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 8C is a bottom view drawing of the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 9 is a block diagram of the signal generation circuit portion of the present invention.
FIG. 10A is a timing signal diagram of the square-wave signal created by the square-wave generator in the signal generation circuit of the present invention.
FIG. 10B is a timing signal diagram of the six sequential signals created by the signal divider circuit in the signal generation circuit of the present invention.
FIG. 10C is a timing signal diagram of the six overlapped sequential signals created by the signal overlap circuit in the signal generation circuit of the present invention.
FIG. 11 is a schematic of one of the high voltage discharge circuits of the present invention.
FIG. 12 is a diagram depicting all six high voltage discharge circuits attached to the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 13 is a side view of an entire furnace system with an oil burner equipped with the plasma point of use fuel treatment and exhaust gas recirculation system according to another embodiment of the present invention.
FIG. 14 is an enlarged side view of an oil burner fuel spray nozzle and igniter assembly removed from the burner air tube for clarity.
FIG. 15 is a side view of an oil burner equipped with the nozzle and igniter assembly of the present invention with the air tube partially cut away for clarity.
FIG. 16 is an enlarged front end view of the plasma electrode tips arrayed around the fuel spray nozzle with the flame retention plate in place according to the present invention.
FIG. 17 is a front end view of the plasma electrode tips arrayed around the fuel spray nozzle with the flame retention plate and electrode tip insulators removed for clarity.
FIG. 18 is a schematic of one of the improved high voltage discharge circuits that supply a multi-frequency high voltage output to one electrode of the nozzle and igniter assembly of the present invention.
FIG. 19 is a diagram depicting a signal generation circuit and six high voltage discharge circuits that produce the multi-frequency high voltage outputs that supply the electrodes of the nozzle and igniter assembly in a fuel burner according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described in further detail in connection with illustrative preferred embodiments for improving combustion in a direct injected internal combustion engine enabling the engine to achieve better fuel economy, reduced pollutant emissions, and more power. Within the scope of the present invention, this system could be applied to gas turbines and to reciprocating internal combustion engines that are direct injected of either the 2-stroke or the 4-stroke type that have been designed for use with any type of combustible fuel including gasoline, diesel or jet fuel.
Referring to FIG. 1 , the present invention is shown mounted in a cylinder head 15 of a diesel engine. An engine block 11 has placed inside it a piston 13 and mounted on top of the engine block 11 is the cylinder head 15 . A combustion chamber 17 is located inside the area surrounded by the engine block 11 , the piston 13 , and the cylinder head 15 . Passing through the cylinder head 15 is a fuel injector 21 that has its lower body surrounded by a ceramic sleeve 23 . A fuel inlet 25 attached to the upper portion of the fuel injector 21 has a fuel passageway 19 that allows fuel to travel to a fuel injection nozzle 27 . This fuel injection nozzle 27 protrudes into the inside of the combustion chamber 17 .
A plurality of embedded wires 29 travel from high voltage terminals 31 mounted on the ceramic sleeve 23 outside and above the cylinder head 15 through the length of the ceramic sleeve 23 including substantially parallel to the lower portion of the fuel injector 21 . These embedded wires 29 extend into the combustion chamber 17 as electrodes 33 . In this embodiment, there are six electrodes 33 arrayed around and below the fuel injector nozzle 27 inside the combustion chamber 17 . All six electrodes 33 are individually connected to high voltage terminals 31 by their own embedded wire 29 .
Referring to FIG. 2 , pressurized fuel is shown entering the fuel injector 21 through the fuel inlet 25 , down fuel passageway 19 , and then out of the fuel injector nozzle 27 into the combustion chamber 17 producing a fuel injection spray pattern 37 . While this is happening, a high voltage discharge 35 occurs between all of the tips of the six electrodes 33 inside the combustion chamber 17 , with the fuel injection spray pattern 37 passing right next to, or through the high voltage discharge 35 . The power for the high voltage discharge 35 that occurs between the six electrodes 33 is produced by a set of six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 (discussed in detail with reference to FIGS. 11 and 12 ).
A set of six spark plug type high voltage wires 39 , 41 , 43 , 45 , 47 and 49 connects on one end to the set of six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 . The other end of the set of six spark plug type high voltage wires 39 , 41 , 43 , 45 , 47 and 49 have an externally insulated connector 32 that secures and protects the connection to the six high voltage terminals 31 mounted on the upper portion of the ceramic sleeve 23 . This set of six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 is controlled by a signal generation circuit 63 which has its position in the system discussed in connection with FIG. 12 and has its operation discussed in detail in connection with FIG. 9 .
FIG. 3A is a side view of the lower portion of the ceramic sleeve 23 that extends through the cylinder head 15 into the combustion chamber 17 . The fuel injection nozzle 27 at the end of the fuel injector 21 and electrodes 33 are on the end of the ceramic sleeve 23 that faces into the combustion chamber 17 .
FIG. 3B shows the only part of the present invention that is actually exposed to the inside of the combustion chamber 17 . The six electrodes 33 are arranged in a circular manner around the fuel injection nozzle 27 .
FIG. 3C shows the same piece of the present invention that is illustrated by FIG. 3A with the difference being that the image was rotated by 90 degrees in order to clarify the shape and position of the electrodes 33 on the end of the ceramic sleeve 23 .
An oblique perspective of the lower portion of the ceramic sleeve 23 further illustrates the placement relationship of the fuel injector nozzle 27 to the electrodes 33 in FIG. 3D .
FIGS. 4A , 4 B and 4 C provide the same set of views as FIGS. 3A , 3 B and 3 C the inclusion of the operation of the high voltage discharge 35 . This gives further clarification of the placement of the high voltage discharge 35 upon the electrodes 33 that are arrayed around the fuel injector nozzle 27 on the end of the ceramic sleeve 23 that faces the combustion chamber 17 . This combustion chamber 17 could, within the scope of the present invention, be installed in any of a variety of engine types to include gas turbines as well as reciprocating 2-cycle and 4-cycle diesel or gasoline direct injected internal combustion engines.
FIG. 4D also shows the same oblique perspective view of the lower portion of the ceramic sleeve 23 as shown in FIG. 3D with the inclusion of the high voltage discharge 35 occurring between the six electrodes 33 . Other numbers of electrodes to create the Ring-of-Fire are possible. Also, the Ring-of-Fire is schematically illustrated in these figures since it is difficult to illustrate completely.
FIGS. 5A , 5 B, 5 C and 5 D show the lower portion of the ceramic sleeve 23 as shown in FIGS. 4A , 4 B, 4 C and 4 D with the inclusion of fuel being injected by a fuel injector 21 . The fuel injection spray pattern 37 of a pintle type of the fuel injector nozzle 27 places a cone of injected fuel centered to the high voltage discharge 35 that occurs between the electrodes 33 inside the combustion chamber 17 . This insures complete combustion initiation of all of the fuel as it is injected.
FIGS. 6A , 6 B, 6 C and 6 D show the lower portion of the ceramic sleeve 23 as shown in FIGS. 5A , 5 B, 5 C and 5 D. The difference is that this time the fuel injector 21 has a fuel injector nozzle 27 of the hole type. The hole type fuel injector nozzle 27 produces a fuel injection spray pattern 37 that has a set of lobes. Each lobe sprays directly next to or through the high voltage discharge 35 thus insuring complete combustion initiation of all of the fuel as it is injected into the combustion chamber 17 .
Referring to FIG. 7A , the fuel injector 21 is installed inside the ceramic sleeve 23 . When fuel injection is taking place, a fuel injector pump (not shown) sends pressurized fuel to the fuel inlet 25 of the fuel injector 21 in a manner known in the art. The pressurized fuel travels through fuel passageway 19 to the fuel injector nozzle 27 that injects the fuel into the combustion chamber 17 . The ceramic sleeve 23 surrounds the lower portion of the fuel injector 21 .
The upper end of the ceramic sleeve 23 that is above the cylinder head 15 has six high voltage terminals 31 that are connected to six embedded wires 29 that extend from the top to the bottom of the ceramic sleeve 23 . The lower ends of the six embedded wires 29 extend from the bottom of the ceramic sleeve 23 into the combustion chamber 17 as six electrodes 33 . These six electrodes 33 are positioned such that their tips are arranged so that they define a hexagon inside the combustion chamber 17 around and below the fuel injector nozzle 27 . This placement is important to insure that the fuel injection spray pattern 37 from the fuel injector nozzle 27 must pass in close proximity to or through the high voltage discharge 35 that occurs between the tips of the electrodes 33 .
FIG. 7B shows a top view of the fuel injector 21 mounted through the ceramic sleeve 23 with the placement of the six high voltage terminals 31 clearly shown.
FIG. 7C is a view from the combustion chamber 17 looking up at the face of the ceramic sleeve 23 and at the tip of the fuel injector 21 with the fuel injection nozzle 27 in the center of the six electrodes 33 .
FIGS. 8A , 8 B and 8 C are similar views as FIGS. 7A , 7 B and 7 C without the fuel injector 21 being shown to further clarify the positions of the high voltage terminals 31 , the embedded wires 29 and the electrodes 33 .
FIG. 9 shows the signal generation circuit 63 in detail. The signal generation circuit 63 controls the high voltage generation circuits 51 , 52 , 53 , 55 , 57 , 59 and 61 . The signals mentioned in this discussion are shown in detail by FIGS. 10A , 10 B and 10 C.
The signal generation circuit 63 has its overall output controlled by an engine timing signal source 65 that turns it on and off through an engine timing signal transmission line 67 . The engine timing signal source 65 controls the signal generation circuit 63 so that at the appropriate time, at or before fuel injection is to take place, the high voltage discharge 35 is initiated. The engine timing signal source 65 keeps the high voltage discharge 35 going for as long as necessary to ensure complete combustion of all of the fuel and air mixture inside the combustion chamber 17 .
The signal generation circuit 63 has within it a square-wave generator circuit 69 that sends through a square-wave signal transmission line 71 , a square-wave signal 73 to a signal divider circuit 75 . The square-wave generator circuit 63 is based on a 555 timer integrated circuit set up to operate as an astable multi-vibrator circuit producing a square-wave signal between 0 and 5 volts at a frequency between 5 and 30 kilo-hertz.
The signal divider circuit 75 divides the square-wave signal 73 into a set of six sequential signals 89 , 91 , 93 , 95 , 97 and 99 , as shown in FIG. 10B , that are sent through a set of six sequential signal transmission lines 77 , 79 , 81 , 83 , 85 and 87 to a signal overlap circuit 101 . The signal divider circuit 75 that divides the square-wave signal 73 into a set of six sequential signals 89 , 91 , 93 , 95 , 97 and 99 is based on the 4017 decade counter integrated circuit.
The signal overlap circuit 101 in turn generates a set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 , as shown in FIG. 10C , and then sends these signals through a set of six overlapped sequential signal lines 103 , 105 , 107 , 109 , 111 and 113 to a signal line driver circuit 127 . The signal overlap circuit 101 uses a bank of twelve 1 N 4004 diodes to generate the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 shown in FIG. 10C .
The signal line driver circuit 127 is activated only when the enable signal from the engine timing signal source 65 , brought in by the engine timing signal transmission line 67 and it allows the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 to go through the signal line driver circuit 127 . The signal line driver circuit 127 uses a 74HCT541 integrated circuit to act as a “gate” to the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 .
It is within the scope of the present invention to have this engine timing signal source 65 be as simple as a cam-shaft position sensor, such as a Hall-effect sensor, or as complicated as a highly sophisticated engine management computer responding in real time to a number of factors to include actual conditions inside of the combustion chamber 17 as they happen in real time as is known in the art. When enabled by the engine timing signal source 65 , the signal line driver circuit 127 then “cleans up” and strengthens the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 without otherwise changing them before they are sent out through a set of six control signal output lines 129 , 131 , 133 , 135 , 137 and 139 to each of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 .
FIG. 11 is an electrical schematic for each high voltage discharge circuit 51 , 53 , 55 , 57 , 59 and 61 . Each of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 is connected to a 24 volt power source 143 and to one of the six control signal output lines 129 , 131 , 133 , 135 , 137 and 139 . When a signal is received by its intended high voltage discharge circuit 51 , 53 , 55 , 57 , 59 and 61 it turns on a power MOSFET 145 labeled Q- 1 . In one embodiment of the present invention, the power MOSFET (Metal Oxide Surface Effect Transistor) 145 labeled Q- 1 is a MTY55N20E made by Motorola and it is rated for 55 amps at 200 volts.
When the power MOSFET 145 labeled Q- 1 is turned on, a high voltage transformer 147 labeled T- 1 then has current flow from the 24 volt power source 143 through a primary winding power lead 149 . The current passes through a primary winding 151 of the high voltage transformer 147 labeled T- 1 , through a primary winding ground lead 153 , through the power MOSFET 145 labeled Q- 1 , through a resistor 155 labeled R- 1 that is rated at 0.2 ohms and 10 watts, and then finally to a low voltage ground connection 157 . This low voltage ground connection 157 is shared by all of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 and it is also used by all of the components of the signal generation circuit 63 . There is a large value capacitor 159 labeled C- 1 which is rated at 1 microfarad and a small value capacitor 161 labeled C- 2 which is rated at 0.01 microfarads. Both are attached in parallel across the primary winding power lead 149 and the primary winding ground lead 153 .
An electrically isolated secondary winding 163 of the high voltage transformer 147 labeled T- 1 has an electrically isolated secondary winding ground lead 165 connected to an electrically isolated “floating” high voltage ground 167 that is shared in the same position of each circuit in all of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 . The electrically isolated secondary winding 163 of the high voltage transformer 147 labeled T- 1 is connected to an electrically isolated secondary winding high voltage output lead 169 . The electrically isolated secondary winding high voltage output lead 169 is in turn connected to the appropriate one of the set of six spark plug type high voltage wires 39 , 41 , 43 , 45 , 47 and 49 which in turn are connected to one of the set of six high voltage terminals 31 on the ceramic sleeve 23 .
FIG. 12 shows the overall combination of elements of the electrical system according to the present invention. This includes a 5 volt power source 171 used by all of the circuitry inside the signal generation circuit 63 . Further a low voltage ground connection 157 is shown as being shared by all of the high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 and with the signal generation circuit 63 .
It should be appreciated that the other ways of creating and controlling the Ring-of-Fire high voltage discharge 35 . Although any means of creating and controlling the Ring-of-Fire must place it so that the injected fuel spray pattern 37 goes next to or through it as fuel enters the combustion chamber 17 .
Referring to FIG. 13 , the present invention also includes a furnace using the Ring-of-Fire or plasma ball ignition system. The furnace in FIG. 13 is shown with a plasma ball high voltage power source 200 . The high voltage power source 200 sends out its plasma generating high voltage output through a bundle of six spark plug type high voltage wires 202 to a fuel burner circuitry housing 206 which is mounted on a fuel burner 208 . An ignition control signal wire 204 connects the high voltage power source 200 to the fuel burner control system 332 shown in FIG. 19 which is inside the fuel burner circuitry housing 206 . It is through the ignition control signal wire 204 that the on/off input for the high voltage source 200 is sent from the fuel burner control system 332 .
A burner air tube 216 connects the fuel burner 208 to a furnace 218 . A blower housing 214 brings in fresh air through an air inlet 210 and also brings in recirculated exhaust through a recirculated exhaust outlet 212 from an exhaust gas recirculation pipe 226 .
The burner air tube 216 is connected to a furnace boiler 218 which is heated by combustion from the fuel burner 208 . The combustion exhaust gases exit the furnace boiler 218 through a furnace exhaust flue 220 . The exhaust gas recirculation pipe 226 enters the furnace exhaust flue 220 through a hole 224 . The exhaust gas from the furnace exhaust flue 220 enters the exhaust gas recirculation pipe 226 through an exhaust gas recirculation inlet 222 . An exhaust gas recirculation valve 228 can control the amount of exhaust gases recirculated. Although the exhaust recirculation valve 228 shown is as a manual valve, it is also possible to use an automatically controlled valve.
Exhaust gas recirculation reduces the amount of oxides of nitrogen formed during combustion by diluting the fresh air entering through the air inlet port 210 with exhaust originally taken from the furnace exhaust flue 220 and conveyed through the exhaust gas recirculation pipe 226 to the blower housing 214 . This creates a measured dilution of the incoming fresh air charge with the exhaust and allows less fuel to be burned for a given volume of gas throughput to the burner 208 while still maintaining the proper fuel to air mixture. This has the overall effect of reducing the temperature at the tip of the combustion flame which is where the oxides of nitrogen are formed.
Once the main flow of exhaust gases pass the exhaust system junction, they then pass by an exhaust flue damper 244 before traveling the rest of the way out of the furnace exhaust flue 220 to the atmosphere.
FIG. 14 shows a nozzle and igniter assembly that resides inside the burner air tube 216 . When in operation, fuel for the nozzle and igniter assembly arrives through the burner nozzle fuel inlet 246 and then travels through a burner nozzle fuel pipe 248 to a fuel nozzle orifice 250 . There is an electrode insulator mounting bracket 252 mounted to the burner nozzle fuel pipe 248 which holds a set of six plasma generation electrode insulators 256 . Each plasma generation electrode insulators 256 has a plasma generation electrode 258 passing therethrough and the end closest to the fuel burner 208 has a plasma generation electrode terminal 254 . The other end of the electrode 258 has a tip 260 . The tips 260 are preferably evenly spaced around and in front of the fuel nozzle orifice 250 . While six electrodes each having insulators are shown, at least three electrodes are needed to achieve the results of the present invention and more than six electrodes are also possible.
FIG. 15 shows the nozzle and igniter assembly mounted inside the burner air tube 216 with the power for the plasma generation coming through the bundle of high voltage wires 202 that are attached to the plasma generation electrode terminals 254 . The other end of the bundle of the high voltage wires 202 is connected to the high voltage power source 200 . On the front end of the air tube 216 is mounted a flame retention plate 264 . The nozzle and igniter assembly has the electrode tips 260 protrude through the flame retention plate 264 .
The plasma generation electrode tips 260 are placed in front of the fuel nozzle orifice 250 . In order to prevent unintentional arcing between the plasma generation electrodes 258 and the flame retention plate 264 , a set of plasma generation tip insulators 262 are mounted on the electrode 258 so as to leave the plasma electrode tips 260 exposed to form the plasma.
FIG. 16 shows the arrangement of the plasma generation electrodes 260 and their insulators 262 with relation to the flame retention plate 264 . Also clearly shown is how the set of plasma generation tips 260 are arrayed evenly around the fuel nozzle orifice 250 . Also shown is a set of eight flame retention plate air passages 266 which are arrayed radially around the center of the flame retention plate 264 .
FIG. 17 is a front end view of the nozzle and igniter assembly with the flame retention plate 264 removed for clarity in order to expose the location of a fuel burner spray nozzle 268 . The fuel burner spray nozzle 268 has the fuel nozzle orifice 250 in the center thereof with the set of six plasma generation electrode tips 260 arrayed radially there around.
When the furnace is in operation, the plasma generating high voltage output from the high voltage source 200 is sent through the bundle of high voltage wires 202 to the nozzle and igniter assembly. There each wire from the bundle of high voltage wires 202 is attached to the respective plasma generation electrode terminal 254 . This allows the plasma generating high voltage output to be conducted along the length of the electrodes 258 to the plasma generation electrode tips 260 .
At the tips 260 , the plasma generating high voltage output from the high voltage source 200 discharges and thereby forms a plasma ball that all of the fuel spraying out from the fuel nozzle orifice 250 must pass through.
The plasma ball is believed to be the main location where the fuel treatment and ignition occur. As best understood, the effect of the plasma ball on the fuel spray that passes therethrough is to remove at least some of the outer valence electrons holding the fuel molecule together. This causes the fuel molecule to break apart into shorter chain hydrocarbons that have also been ionized as a result of passing through the plasma. These ionized shorter chain hydrocarbons not only burn cleaner and more efficiently when compared to longer chain hydrocarbons, the ionized shorter chain hydrocarbons also ignite rapidly upon contact with oxygen due to their ionization state.
FIG. 18 shows the schematic diagram of a single high voltage discharge circuit out of the at least three high voltage discharge circuits within the high voltage power source 200 . The number of high voltage discharge circuits is equal to the number of electrodes used in the device. This circuit is controlled through a control signal input line 270 that is connected to the gates of a set of three matching power Metal Oxide Surface Field Effect Transistors (henceforth referred to as MOSFETs) 272 . These three MOSFETs 272 are the switches that when turned on allow current to flow from a 24-volt power source 283 through a primary winding 276 of a high voltage transformer labeled T 1 277 . The three MOSFETs 272 connect the other end of the primary winding 276 to a low voltage ground connection 284 through a 0.2 ohm resistor 285 . Between the low voltage side of the primary winding 276 and low voltage ground 284 are a capacitor of 4700 picofarads 286 , another capacitor of 4700 picofarads 288 and a capacitor of 2200 picofarads 290 and a high amperage diode 282 . When used in this circuit, the high amperage diode 282 acts as a free wheeling diode.
Connected across the leads to the primary winding 276 are a capacitor of 0.047 microfarads 292 , a capacitor of 0.1 microfarads 294 and a capacitor of 2200 picofarads 296 . Also attached to the power side of the primary winding 276 connected to the low voltage ground 284 are a capacitor of 4700 picofarads 298 , a capacitor of 2200 picofarads 300 , a capacitor of 0.1 microfarads 302 and a capacitor of 1.0 microfarad 304 .
Connected to a secondary winding 278 of the high voltage transformer labeled T 1 277 is a spark plug type high voltage wire 280 that eventually goes to the plasma generation electrode terminal 254 of one of the plasma generation electrodes 258 . The other lead from the secondary winding 278 of the high voltage transformer labeled T 1 277 is an electrically isolated secondary winding ground lead 279 connected to an electrically isolated “floating” high voltage ground 281 .
When the power MOSFETs 272 are turned on by an input from a signal generation circuit 330 (shown in FIG. 19 ) through the control signal input line 270 more than just the electricity from the 24 volt power source 283 flows through the primary winding 276 of the high voltage transformer labeled T- 1 277 . Four capacitors 298 , 300 , 302 , and 304 of different values also discharge through the primary winding 276 of the high voltage transformer 277 .
These four capacitors 298 , 300 , 302 , and 304 also set up a resonant tank circuit with the primary winding 276 which acts as the inductor in the tank circuit. Since each of the four capacitors 298 , 300 , 302 , and 304 have a different value, four resonant tank circuits are set up, each one resonating at a different frequency. When the power MOSFETs 272 are turned on, the diode 282 plays an important role in this resonance in that the diode 282 and the power MOSFETs 272 allow current to flow in both directions during resonance through the primary winding 276 . When the power MOSFETs 272 are turned off, resonance can occur for another half cycle through the diode 282 .
This does not however stop circuit resonance because at this point the three capacitors 292 , 294 , 296 (each of a different value) that are across the leads to the primary winding 276 take over and continue to resonate in the resonant tank circuit they form. Since these three capacitors 292 , 294 , and 296 all have different values, three different tank circuits are formed that continue to resonate at three different frequencies even after the power MOSFETs 272 are turned off.
Also contributing to the collection of various resonant frequencies are the three capacitors 286 , 288 , and 290 that are connected between the lead of the primary winding 276 opposite its lead connected to the 24 volt power source 283 and the low voltage ground 284 . Although the values of two of the capacitors 286 and 288 are the same, it was determined empirically that this combination produced the most vigorous plasma discharge.
FIG. 19 shows how a set of six high voltage discharge circuits 318 , 320 , 322 , 324 , 326 , and 328 of the type shown in FIG. 18 are put together inside the high voltage power source 200 . Not only do the individual high voltage power discharge circuits 318 , 320 , 322 , 324 , 326 , and 328 produce a wide variety of resonance frequencies, these circuits also interact with each other through the electrically isolated “floating” high voltage ground 281 . As a result, all six of the plasma generation electrodes 258 are contributing to the ball of plasma at all times. It is believed that this is a reason why the plasma ball is formed between the set of six electrode tips 260 instead of what would appear to be a circular arc with a hole in it that would allow fuel to pass through without being ionized.
When the fuel burner control circuit 232 inside the fuel circuitry housing 206 turns on the fuel burner 208 , the fuel burner control circuit 232 also sends an enable signal through the ignition control signal wire 204 to the signal generation circuit 330 . The other aspects of the circuit in FIG. 19 are similar to the circuit block diagram shown in FIG. 12 . The main difference is that the six high voltage outputs go through the high voltage wires 306 , 308 , 310 , 312 and 314 which are grouped together into a bundle of high voltage wires 202 . The wires 202 connect with the nozzle and igniter assembly in the oil burner 208 instead of being connected to an injector-igniter assembly 23 in an internal combustion engine as described in FIG. 12 .
The other major difference is that plasma generation for use in the fuel burner 208 is continuous for as long as it is in operation to provide a flame to the furnace boiler 218 . It is because of this continuous plasma generation that the approach of having three MOSFETs 272 in parallel with each other was adopted in order to reduce heat buildup therein. In order to handle the greater fuel flow rate found in larger furnaces and similar installations it was necessary to develop the improved high voltage discharge circuit design in order to produce a larger and more intense plasma.
It is to be understood that although the present invention has been described with regards to preferred embodiments thereof, various other embodiments and variants may occur to those skilled in the art, which are within the scope and spirit of the invention, and such other embodiments and variants are intended to be covered by the following claims. | An apparatus and method for the creation, placement and control of an area of electrical ionization within an internal combustion engine combustion chamber or a fuel burner for a furnace is disclosed. A furnace includes a fuel source, a fuel burner, a plasma nozzle and igniter assembly, and the associated housing and flue structures. The plasma nozzle and igniter assembly is arranged so that the fuel sprayed out from the nozzle into the combustion area passes through or in close proximity to the area of plasma ionization. A fuel burner equipped with this electrical ionization device has its fuel efficiency enhanced by the complete and immediate combustion of substantially all of the fuel that passes through the area of plasma ionization. Exhaust gas recirculation using this system is also disclosed. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention, in general, relates to an apparatus for the scanning of working levels and, more particularly, to an apparatus for scanning the working level between a cutting tool and a cutting surface in water jet cutting machines and laser cutting machines for the prevention of damage to tools as may otherwise result from collision.
[0003] 2. The Prior Art
[0004] Apparatus manually adjustable and controllable by an operator and provided with sensors for scanning working levels are known. They do, however, suffer from such drawbacks as requiring extreme attention on the part of the operator and their sensors being easily be damaged by a reflected water jet or by abrasion. Such apparatus are generally incapable of detecting very small surface irregularities such as burrs, scales, dripping residues or rust, so that there is always a high risk of damage to their cutting tools.
[0005] German Utility Model U1 299 05 304.0 discloses a pneumatic device for water jet and laser cutting machines which seeks to avoid collisions between the cutting tool and surface irregularities in the cutting material by dynamically scanning the surface.
[0006] One disadvantage of such devices is that at the occurrence of a mechanical overload as may be caused by a collision of the tool, the sluggishness of the pneumatic drive and the slow rate at which such devices process measured values, they offer no reliable protection from damage to the cutting tool. Since neither the speed of response of such devices nor stroke and surface pressure of the scanning arm can be set or programmed by an operator, damage to costly sensitive material as a result of scratches is rather likely.
OBJECTS OF THE INVENTION
[0007] It is a general object of the invention to provide an electr-omechanical apparatus for scanning the working level of water jet and laser cutting devices.
[0008] A more specific object of the invention resides in the provision of an apparatus for scanning the working level of a water jet or laser cutting machine whose scanning arm surface pressure on the material to be cut may be programmed.
[0009] Yet another object of the invention is to provide an apparatus for scanning the working level of a water jet or laser cutting machine which is provided with collision protection means of adjustable sensitivity or responsiveness.
[0010] Still another object of the invention resides in the provision of a scanning apparatus of the kind referred to which prevents mechanical overloads of the cutting device.
BRIEF SUMMARY OF THE INVENTION
[0011] In the accomplishment of these and other objects, the present invention, in a preferred embodiment thereof, provides an apparatus for scanning the working level of a water jet or laser cutting tool provided with a scanning arm which is movable into its operating position by a linear motor and the surface pressure of which is electrically or mechanically adjustable and controllable throughout its entire stroke, in dependency of the material to be treated. Alternatively, the scanning arm may be programmed to any position along its stroke.
[0012] Preferably, the linear motor unit including a linear slide and linear guide rod of the scanning arm as well the scanning arm mounted on the linear guide rod are mounted for substantially omnidirectional pivotal movement by a flexible mount and/or ball joint seated in a cantilever, the linear motor unit being maintained in a stable neutral position by at least one spring arranged between the linear motor unit and the cantilever.
[0013] A collision switch structured as a well known inductive proximity switch may be actuated by a link connected to the linear motor unit.
[0014] The link is movably connected to the linear motor unit and may be pivotally and slidingly moved in a fulcrum in a support, support and fulcrum being mounted on a spindle and may be adjusted relative thereto for changing the transmission ratio of the lever arrangement.
[0015] Other objects and advantages will in part be obvious and will in part appear hereinafter.
DESCRIPTION OF THE SEVERAL DRAWINGS.
[0016] The novel features which are considered to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, in respect of its structure, construction and lay-out as well as manufacturing techniques, together with other objects and advantages thereof, will be best understood from the following description of preferred embodiments when read in connection with the appended drawings, in which:
[0017] [0017]FIG. 1 is a schematic frontal view of a scanning apparatus mounted on the tool support of a cutting device, partially in section;
[0018] [0018]FIG. 2 is a schematic side view of the scanning apparatus of FIG. 1 in an operative state; and
[0019] [0019]FIG. 3 is a schematic view similar to FIG. 2 with the apparatus in a state of collision.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] A linear motor unit 13 is seen to be mounted on a cantilever 6 extending from a tool support of a cutting tool 4 . The tool 4 may be a water jet or a laser diode of the kind well known in the art. The linear motor unit 13 is mounted on the cantilever 6 by means of a ball joint 3 and flexible mount 5 and is supported in a predetermined neutral position by a spring 7 extending between the unit 13 and the cantilever 6 .
[0021] The linear motor 11 itself is mounted for sliding movement on a linear guide rod 14 by means of a linear slide bracket 10 . The brackt 10 is secured against rotary movement by an appropriate latch 20 . The linear guide rod 14 extends through the ball joint 3 in the cantilever 6 and is provided at one of its ends with a guide head or chuck 2 . A scanning arm 1 is mounted on the guide head or chuck 2 for sliding movement as well as for pivotal movement in one plane. The connection between the chuck 2 and the scanning arm 1 includes a breaking point of the kind well known in the art and designed to brake the arm off the chuck when a force exerted on the arm exceeds a certain level.
[0022] The scanning arm 1 preferably is a hollow tube and may be connected, at its upper end, to a source of water or pressurized gas (not shown). An annular support or foot at the lower end of the scanning arm 1 is provided with nozzles directed toward the material 19 to be cut so that a protective fluid cushion may be formed between the foot and the surface to be cut.
[0023] Within the linear motor unit 13 there is provided a transparent scale 12 made of glass or the like. The scale 12 communicates with an optical encoder 22 which is provided in the interior of linear motor unit 13 as well.
[0024] A spindle 15 is disposed substantially parallel to the linear guide rod 14 , and a longitudinally or vertically adjustable support 17 with a pivotal bearing or fulcrum 9 is mounted on the spindle 15 . A collision switch 8 structured as an inductive proximity switch is seated below the fulcrum 9 . At its furthest point from the ball joint 3 the linear motor unit 13 is connected by a rotary bearing 18 and a cantilever to a link 16 . The connection, i.e. the rotary bearing 18 , between the link 16 and the cantilever constitutes a gimbal and by adjusting the fulcrum 9 along the lever 16 by movement of the support 17 , the transmission ratio of the link 16 may be changed. The end of the link 16 opposite the rotary joint 18 constitutes one pole of a collision switch 8 and serves at times to open the switch 8 (see FIG. 3) to switch off the cutting device. The link 16 slidingly extends through the fulcrum 9 associated with the vertically adjustable support 17 . In a normal state of operation of the water jet or laser cutting device the joint 18 , the fulcrum 9 and the collision switch 8 are in axial alignment and the cutting device will be in an energized state by way of electrical contacts of the inductive proximity switch.
[0025] For purposes of operating the apparatus, the cutting tool 4 is properly placed relative to the material 19 to be cut and the working distance between cutting tool 4 and the surface of the material 19 is programmed or set. The support pressure of the scanning arm 1 is also programmed or set. The sensitivity of the collision switch 8 is set by means of the support 17 of the fulcrum 9 on the spindle 15 by positioning the support 17 close to or remote from the collision switch 8 , thus realizing different transmission ratios of the link 16 . Positioning the fulcrum 9 close to the collision switch 8 denotes “not sensitive” whereas positioning it remote from the switch denotes “sensitive”. As soon as the water cutting device is in an operative state and a surface irregularity of the material 19 being cut is detected by the engagement of the scanning arm 1 on the material, the scanning arm 1 will pivot in an evasive direction and transmit the deflection to the linear motor unit 13 by way of the linear guide rod 14 and, by way of the joint 18 , to the link 16 guided by the fulcrum 9 .
[0026] The deflective movement causes the collision switch 8 to move out of its aligned position relative to the link 16 thereby turning off the cutting device in time to prevent damage or destruction of the expensive cutting tool.
[0027] The advantages of the apparatus in accordance with the invention are, among others, that the use of a linear motor for placing a scanning arm on the surface of material to be cut yields a high reaction speed. This, in turn, results in a precision or accuracy of a programmable or controllable load pressure on the surface of about 0.05N for each point along the stroke. Because of reduced friction, augmented by fluid pressure at the bearing seat, between the scanning arm and the surface, the cutting machine may be operated at a higher speed. It also allows the material to be cut to be held down more securely.
[0028] Minimum spacing between the cutting tool and the surface of the material to be cut is can be attained as the values obtained by the transparent scale and an optical encoder can be used directly to control the cutting tool at a precision of about 0.01 mm.
[0029] Furthermore, because of the increased sensitivity of the scanning apparatus the water jet or laser cutting tool can be reliably shut down before it may become damaged as a result of a collision. The sensitivity or responsiveness of the apparatus may easily be adjusted by changing the transmission ratio of the link in accordance with different requirements. | An apparatus for scanning the working level of a cutting tool relative to the surface of a workpiece and provided with a scanning arm adapted to move relative to the surface of the work piece and movable in response to an irregularity in the surface for opening a switch thereby to disconnect the cutting tool from a source of power. | 1 |
FIELD OF THE INVENTION
The present invention relates to a contact-disk system having a rotatable contact disk and a plurality of contact elements, the contact disk having a plurality of paths and each contact element being assigned to one path. The present invention also relates to a method for controlling a windshield-wiper motor using a contact-disk system having a rotatable contact disk and a plurality of contact elements, the contact disk having a plurality of paths and each contact element being assigned to one path. Furthermore, the present invention relates to a windshield-wiper motor which comprises a contact-disk system having a rotatable contact disk and a plurality of contact elements, the contact disk having a plurality of paths and each contact element being assigned to one path.
BACKGROUND INFORMATION
Conventional windshield-wiper devices may include contact-disk systems as well as methods for controlling windshield-wiper motors for cleaning of motor vehicle windshields. The windshield-wiper devices may be operated by a switch which may be located in the vehicle interior, the switch being implemented, for example, as a steering-column switch. By operating the steering-column switch, the windshield-wiper device may be shifted from a switched-off state to at least one operating state. The operating states may be implemented by a plurality of windshield-wiper speeds and an intermittent control.
To ensure that the windshield wipers do not come to rest in an intermediate position when the windshield wiper is switched off by the steering column switch, but instead are properly guided back to park position, contact-disk systems may be used. Such contact-disk systems may maintain a closed circuit, in which the windshield-wiper motor operates, until the windshield wipers have reached the park position.
FIG. 1 shows a contact disk 110 which may be used in a conventional contact-disk system. A contact disk 110 of this kind may be installed in generic windshield-wiper motors in such a manner that it rotates in synchronism with the windshield-wiper motor. Contact disk 110 establishes contact with three contact elements, which in each case glide on one path of contact disk 110 . A first contact element glides on outer path 120 , which has a gap. A second contact element glides on inner path 122 , which is implemented as a short path, and a third contact element glides on a center path 121 , which is continuous. Such a construction may maintain a current flow in all motor settings, except for the end position and in an area approaching the end position. This may be achieved by a contact element, which is connected to the positive pole of the battery, gliding on outer path 120 . A contact element gliding on center path 121 is connected to the wiper motor. Therefore, a current flow from the positive pole of the battery to the wiper motor is maintainable as long as the first contact element glides on a conductive region of outer path 120 . The current flow may only be interrupted when contact disk 110 has rotated to the point where the contact element is located in the gap in outer path 120 . Due to the inertia of the motor, the contact disk continues to rotate despite the interrupted current flow. However, this further rotation may come to an end when the conductive region of short, inner path 122 connects with a contact element. This contact element is switched such that the motor is short-circuited and may be actively braked in this manner.
Due to the three paths of a conventional contact disk, it may have a certain minimum size. However, in the case of windshield-wiper motors it is desirable to achieve an overall size that is as small as possible, and, therefore, in particular also a small size of the contact disk. A small size of the contact disk may also be desirable in the production of windshield-wiper motors, in particular in rear-wiper motors with oscillating gears, where the contact disk may be required to be arranged with the contacting on the opposite side with respect to the oscillating gear. For this reason, the windshield-wiper motor may be required at present to be rotated on the assembly line during production, which may make the production process expensive.
SUMMARY OF THE INVENTION
The present invention builds on the conventional contact-disk system in that the contact disk may have two paths and in that two selected contact elements of the plurality of contact elements may always be at the same electrical potential and glide on the same path. In this manner, an electric current flow may be maintained, with a two-path contact disk, until the park position of the windshield wiper is reached or until shortly before the park position has been reached. Because the contact disk may require no more than two paths it may have a smaller size and a smaller radial overall width, which may be desirable with respect to the mentioned overall size of the windshield-wiper motor and in view of the manufacturing process.
The selected contact elements may glide on a first path, which may have an electrically conductive and an electrically insulating area, and at least one contact element of the selected contact elements is connected to the electrically conductive area. If the windshield-wiper motor is switched off by operating the steering-column switch, an electrical connection to the wiper motor may be maintained at least via one of the selected contact elements, since at least one of the selected contact elements may always be in contact with the electrically conductive area of the first path.
The electrically insulating area of the first path may be implemented by a gap in a conductive path, and the selected contact elements may have a spacing that is larger than the gap of the first path. Therefore, given a circular contact disk, the electrically insulating area may be realized by a cut-out with radially extending boundaries. If the opening angle of this gap is less than the clearance angle of the selected contact elements, it may be assured in this manner that one of the selected contact elements is always in contact with the electrically conductive area of the first path.
A first, additional contact element may glide on the first path. This first additional contact element may be used to maintain an electrical connection between the contact disk and the positive pole of the vehicle battery. Therefore, even when the steering-column switch is in the off-position, an electrical connection mat be maintained between the positive pole of the battery and the motor via the first additional contact element and at least one of the selected contact elements. Only when the first additional contact element leaves the electrically conductive area of the first path and is located in the insulating area of the first path, may the current flow be interrupted.
A second path may have an electrically insulating area and an electrically conductive area. A second additional contact element may glide on the second path. This contact element may be used to realize an electrical short-circuit of the motor and to actively brake the motor in this manner once the park position has been reached.
The gap in the first path, the electrically conductive area of the second path, the first additional contact element and the second additional contact element may be arranged with respect to one another in such a manner that a state exists in which neither the first additional contact element nor the second additional contact element are connected to an electrically conductive area of the first path and the second path, respectively. Although the current flow in the electrical circuit of the windshield-wiper motor may already be interrupted, the motor and the contact disk may still continue to rotate, due to their inertia. During this phase the motor speed may be reduced, and an active braking of the motor may only occur, due to the electrical short-circuit, when the second additional contact element makes contact with the electrically conductive area of the second path.
The angular range, which may be covered by the electrically conductive area of the second path, may be less than the angular range that is covered by the electrically insulating area of the first path. As a result, the first additional contact element may have already left the conductive area of the first path due to the rotation of the contact disk, while the second additional contact element may have not yet reached the conductive area of the second path. Therefore, the motor may be neither actuated nor actively braked in this intermediate state. The motor may continue to rotate due to its inertia, with the rotational speed decreasing, however. Only when the electrically conductive area of the second path makes contact with the second additional contact element, may the motor be finally braked.
These contact elements may be contact springs. In this manner, a reliable contact between the contact disk and the contact elements may be established.
The present invention may build on a conventional method in that a contact-disk system according to the present invention may be used to control a windshield-wiper motor. In this manner, a contact-disk system according to the present invention may be implemented by a control method.
In an exemplary method according to the present invention it may be desirable if a switch connected to the contact-disk system is operated and if a rotation of the contact disk is maintained until the second additional contact element is connected to the electrically conductive area of the second path. Thus, the control method may allow the windshield wipers to be guided from one operating position to a park position in a reliable manner.
In this context, prior to connecting the second additional contact element to the electrically conductive area of the second path, the connection of the first additional contact element to the electrically conductive area of the first path may be interrupted. Although the electrical connection of the motor and the battery may already be interrupted during this created intermediate state, rotation may still occur nevertheless, due to the inertia of the involved components, although the rotational speed of the motor may decrease. Only when the second additional contact element contacts the electrically conductive area of the second path may an active braking of the motor occur.
The present invention may build on a conventional windshield-wiper motor in that it may have a contact disk according to the present invention. As a result, the windshield-wiper motor may implement desired features of a contact disk according to the present invention and an exemplary method according to the present invention. A windshield-wiper motor may be manufactured that has a reduced size.
The present invention may be based on a recognition that, by an appropriate arrangement of contact elements and a suitable geometric design of a contact disk, the functions of a three-path contact disk may be realized, as it may be used in conventional windshield-wiper motors, or by two-path contact disks. Therefore, windshield-wiper motors according to the present invention may also be produced in smaller sizes. The manufacturing process, in particular, may be simplified since a rotation of the motor on the workpiece-carrier of the assembly line may no longer be required.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a conventional contact disk.
FIG. 2 shows a contact-disk system according to an exemplary embodiment of the present invention.
FIG. 3 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in switched-on state.
FIG. 4 shows a substitute circuit diagram of the circuit according to FIG. 3 .
FIG. 5 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a first intermediate state.
FIG. 6 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a second intermediate state.
FIG. 7 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a third intermediate state.
FIG. 8 shows a substitute circuit diagram of the circuits according to FIGS. 5 through 7.
FIG. 9 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a fourth intermediate state.
FIG. 10 shows a substitute circuit diagram of the circuit according to FIG. 9 .
FIG. 11 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a switched-off state.
FIG. 12 shows a substitute circuit diagram of the circuit according to FIG. 11 .
DETAILED DESCRIPTION
In the following description of the drawings, identical elements have been provided with the same reference numerals.
FIG. 2 shows a contact-disk system according to an exemplary embodiment of the present invention in a top view. The contact-disk system includes a contact disk 10 and a plurality of contact elements 12 , 14 , 16 , 18 . Contact elements 12 , 14 , 16 , 18 are in the form of contact springs. Contact disk 10 has two paths 20 , 22 . First path 20 has a relatively long electrically conductive area 24 and a comparatively short electrically insulating area 26 , which is realized by a gap in path 20 . First path 20 is located in the radial direction outside of second path 22 . This second path 22 has a relatively long electrically insulating area 28 and a comparatively short electrically conductive area 30 . The electrically conductive area 30 is implemented as a short connecting piece to the electrically conductive area 24 of first path 20 . Two contact elements 12 , 14 of the plurality of contact elements 12 , 14 , 16 , 18 , which are referred to as selected contact elements 12 , 14 , have a clearance angle with respect to their contact areas 36 , 38 that is greater than gap 26 in first path 20 . In this manner, at least one of contact elements 12 , 14 is always in contact with the electrically conductive area 24 of first path 20 . First additional contact element 16 slides on first path 20 . Second additional contact element 18 slides on second path 22 . The angular range, which is covered by gap 26 in first path 20 , is larger than the angular range that is covered by electrically conductive area 30 of the second path. Contact point 40 of first additional contact element 16 and contact point 42 of second additional contact element 18 as well as gap 26 in first path 20 and electrically conductive area 30 of second path 22 are arranged in such a manner with respect to each other that there exists a state in which neither first additional contact element 16 nor second additional contact element 18 is in contact by their respective paths. Also, the arrangement of first additional contact element 16 and second additional contact element 18 is and gap 26 in first path 20 and of electrically conductive area 30 of second path 22 are selected such that a state exists in which second additional contact element 18 is in contact with electrically conductive area 30 of second path 22 , while first additional contact element 16 is located in electrically insulating area 26 of first path 20 and thus does not have any electrical contact to contact disk 10 .
FIG. 3 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a switched-on state. A switch 34 , which may be in the form of a steering-column switch, establishes a connection between terminal 53 and the positive pole of the vehicle battery. In this manner, the positive potential is applied to motor 32 via terminal 53 , a polarity-reversal damping diode 44 and a coil 46 . This is independent of the position of contact disk 10 with regard to contact elements 12 , 14 , 16 , 18 , an arbitrary instantaneous survey of contact disk 10 rotating synchronously with motor 32 being depicted in the present case.
FIG. 4 shows a substitute circuit diagram according to FIG. 3 . It is shown that terminal 53 may always be at a positive potential via switch 34 . Contact disk 10 , which is symbolized by a switch activated by motor 32 , alternates between several switching states; at certain times an additional connection of motor 32 to the positive pole exists via terminal 53 a . This is symbolized by the solid line in the symbolic depiction of contact disk 10 . At other times, an additional connection of motor 32 to terminal 53 is provided. This is symbolized by the dashed line to the right of the symbolic depiction of contact disk 10 . There is also a state in which contact disk does not establish any further connection of motor 32 to one of the terminals 53 , 53 a , which is represented by the center dashed line of the symbolically represented contact disk 10 . Regardless of the switching states of disk 10 , a positive potential may be given at motor 32 via coil 46 in switched-on state, i.e. the state in which switch 34 creates a connection to the positive pole.
FIG. 5 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a first intermediate state. Switch 34 has been switched to turn the window wiper off, so that a connection to the negative pole of the battery is now given by switch 34 . However, motor 32 is still provided with the positive potential via terminal 53 a , contact element 16 , contact disk 10 and contact element 12 . In the instantaneous survey represented in FIG. 5, contact element 14 is locate in the electrically insulating area of first path 20 of contact disk 10 . Since the space between the selected contact elements 12 , 14 is larger than gap 26 in first path 20 of contact element 10 , contact disk 10 may always maintain a connection to motor 32 . Second additional contact element 18 , which is at a negative potential via terminal 53 , is not in contact with the contact disk, since it is located in the electrically insulating area of second path 22 .
FIG. 6 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a second intermediate state. This second intermediate state corresponds to the first intermediate state according to FIG. 5, with the exception that the contact of the positive pole is now provided via the other selected contact element 14 .
FIG. 7 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a third intermediate state. This third intermediate state also corresponds to the first intermediate state according to FIG. 5 and the second intermediate state according to FIG. 6, with the exception that the connection between the positive pole and motor 32 is maintained by both selected contact elements 12 , 14 in the instantaneous survey according to FIG. 7 .
FIG. 8 shows a substitute circuit diagram of the circuits according to FIGS. 5 through 7. In all states, the positive pole is connected to the motor via terminal 53 a , so that its operation may be maintained.
FIG. 9 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a fourth intermediate state. This fourth intermediate state electrically differs from the first intermediate state, the second intermediate state and the third intermediate state. In the fourth intermediate state according to FIG. 9, the first additional contact element 16 is located in electrically insulating area 26 of first path 20 . Therefore, the positive potential is no longer at the selected contacted elements 12 , 14 , so that there is also no longer any voltage at motor 32 . Second additional contact element 18 is located in the electrically insulating area of second path 22 , but just before contacting the electrically conductive area. Starting from the state according to FIG. 9, a further rotation of the contact disk may occur due to the inertia of the involved components.
FIG. 10 shows a substitute circuit diagram of the circuit according to FIG. 9 . It is shown that neither terminal 53 a nor terminal 53 is connected to the motor. This indicates that there is neither a positive potential for the normal operation of motor 32 , nor is there a negative potential at motor 32 , which would short-circuit motor 32 .
FIG. 11 shows an electrical circuit including a contact-disk system according to an exemplary embodiment of the present invention in a switched-off state. In accordance to FIG. 9, here, too, contact element 16 is located in electrically insulating area 26 of path 20 . In contrast to FIG. 9, however, in the instantaneous survey according to FIG. 11, contact element 18 is in electrically conductive area 30 of second path 22 . Thus, a connection exists between the negative pole and the motor via terminal 53 and contact element 18 . Motor 32 is short-circuited and thereby actively braked. The windshield-wiper is in park position.
FIG. 12 shows a substitute circuit of diagram of the circuit according to FIG. 11 . It may be seen that the switch, which symbolizes contact disk 10 , connects motor 32 to the negative pole, so that it is short-circuited.
The preceding description of exemplary embodiments according to the present invention may be for illustrative purposes only, and is not mean to restrict the invention. Various changes and modifications may be possible within the framework of the present invention, without leaving the scope of the present invention and its equivalents. | A contact-disk system is described having a rotatable contact disk and a plurality of contact elements, the contact disk having a plurality of paths and each contact element being assigned to one path. Two selected contact elements of the plurality of contact elements are always at the same electrical potential and glide on the same path. A windshield-wiper motor and a method for controlling a windshield-wiper motor are also described. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application hereby incorporates by reference the contents of and claims priority to U.S. provisional application Ser. No. 60/229,676 filed Sep. 1, 2000.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of risk management and more particularly to a web based system and method for defining the risk mitigation needs of a user or client, for formulating a program to identify solutions for such needs and to create recommendations for financial products and related solutions (such as for example futures, options, insurance, long term investments, future currency contracts, etc.) to meet such needs. The invention has the means for the preparation of premium or price indications and quotations for such products, as well as the ability to bind in real time and for the ultimate issuance of the financial products consistent with the recommended solutions. The system further has the ability to process and transact the purchase of insurance and other financial products. The program is implemented in accordance with client data inputted into the system.
BACKGROUND OF THE INVENTION
[0003] The creation of a risk management program and a financial portfolio is often a difficult and complex process. Significant assessment is usually required to understand the risks associated with a particular business entity and to identify appropriate solutions for the mitigation of such risks. Collection of necessary data required to assess business activities in order to define risks for any particular business entity is a difficult and time-consuming process. In addition, once appropriate data is collected, the process of comparing that data to existing databases in order to provide recommended solutions for risks identified from such data is also a complex and complicated process. Many factors are required to determine the type of solutions (whether they be insurance or other investment solutions such as futures, options, future currency contracts, etc.), as well as the many types of risks to be mitigated. While it has heretofore been common to use a computer based system to assist risk managers, financial advisors, insurance brokers or agents to collect data and to prepare necessary information for a client to evaluate, as well as for maintaining accurate records, the graphical user interface (“GUI”) needed for a particular computer system to perform these tasks may vary greatly depending upon the risk mitigation solutions under consideration. Frequently, there are numerous screens on a computer program available for each type of product. Further, there are numerous variables that determine a client's needs to mitigate risks, assessment of the size of the risk and appropriate solutions for such risks. People responsible for managing risk have not heretofore had available a web based solution that will enable such managers to quickly and effectively identify risks, analyze the risks and provide the means for access to sources that will provide appropriate solutions to mitigate the risks by the use of, for example, customized financial products.
OBJECTS OF THE INVENTION
[0004] It is therefore an object of the invention to provide a web based system and method which is accessible over Internet protocols to facilitate the identification of financial products to mitigate risks and for facilitating the purchasing of such products on line. The system and method of the present invention enables risk managers, such as Chief Financial Officers or other persons in a business entity responsible for the risk management function, to identify risks unique to their business activity, to identify products and solutions for the identified risks, to design unique products and solutions specific to their risks and to provide such solutions in real time to the end users. The system of the present invention, sometimes referred to herein as the nuServe system, is directed at defining the solutions to the identified risks. By way of example, insurance products are discussed herein as one such solution.
[0005] Another object of the invention is to provide a system and method as a means for accelerating real time delivery of financial products and services by enabling transactions and communication among suppliers of such products through the nuServe system as a hub facility.
[0006] Other objects, features and advantages of the invention will be apparent to those skilled in the art after appreciating the invention from the description below.
BRIEF SUMMARY
[0007] The invention is accordingly characterized by a process carried out by the nuServe system, which is referred to herein as the nuServe process. The nuServe system and process is made available to users, such as persons responsible for managing risks, by having access to a web site (the “nuServe web site”) that maintains the system. The nuServe web site enables operations of the nuServe process and incorporates programs or engines referred to as the iSolve and QSolve engines. The iSolve engine generally provides the function of computing various financial product values and prices/premiums of different lines of business or types of coverage required by the user. The QSolve engine will generally be used for providing quotations of premiums for only a particular line of business or insurance coverage. The iSolve engine enables the user to understand particular risks, thus, enabling management of such risks, to identify known or unmet exposure to risk and the ability to analyze such risk and exposure to risk. The iSolve engine then provides solutions to mitigate such risks and exposure to risk through the use of customized risk management solutions. By access to the nuServe web site, a user can employ iSolve to enable customers to identify and select financial products of particular suppliers most suitable to the customers' needs. The iSolve engine includes filters for matching the needs of a user to the criteria of a financial product supplier. Such a user may, for example, be an insurance company, an insurance broker or a risk manager, who might be the Chief Financial Officer, of a business entity. An insurance broker for example, would use iSolve to expedite the identification of the best insurance products or solutions to fit a customer's particular needs, and to provide premium quotations for such products or solutions, and to bind such products in real time. Insurance companies (companies that issue insurance policies) or insurance brokerage firms may also participate through the nuServe process. Purchasers of financial products which have been identified to mitigate the purchasers' identified risks will have access to such companies and firms based upon the solutions to that purchaser's profile requirements.
[0008] To begin the process, a user first creates a unique risk profile using a program that extracts customer data in a graphical format to build a specific risk profile. The program, referred to as “Profiler” is accessed once a user is on the nuServe web site and has logged in and registered with the nuServe system. Because insurance products may provide one solution, Profiler also prepopulates a universal insurance application, which in part completes multiple monoline applications, to enable the provision of multiline insurance indications.
[0009] The GUI for the Profiler is used to extract customer data in a graphical format to build the specific risk profile. The data acquired through this process identifies specific risk management needs particularly for small and medium sized businesses. Indications will be provided as to the lines of business risks required to be considered, appropriate endorsements and financial product limitations, as well as initial ballpark price or premium levels. The system will provide the user with the ability to conduct a cost-benefit analysis of what is currently insured, against what is uninsured. A transaction link enables the user to bind on-line through the nuServe web site in real time.
[0010] The system of the invention includes a GUI that enables persons responsible for managing risks to navigate the process and identify customized risk needs. The data supplied will identify risk needs and will populate multiple databases enabling calculation of financial product limits and premium or price indications. The system also utilizes communications links to other systems of brokers, insurance agents, insurance companies, suppliers of other financial products as well as to appropriate data feeds. The system uses known programming languages and databases as well as uniquely designed scripting language to implement the process.
[0011] Accordingly, the invention provides a web based system maintained at a central server and accessible to users over the Internet for defining risk mitigation needs of a user based upon profile data of the user, and includes means for inputting profile data into the system, means for accumulating and saving the data in databases to enable analysis of that data, and means for analyzing the profile data and for identifying financial risks correlated to that profile data. The system also includes means for identifying financial products which provides solutions to mitigate such risks, and means for indicating the cost to acquire or purchase those financial products. Finally, the invention includes means for matching the needs of a user to a supplier of financial products and for binding in real time a commitment for the purchase and sale of the financial products, and means for processing a transaction to implement the purchase and sale of the financial products.
[0012] The invention also provides for a process to define such risk mitigation needs, which includes the steps of inputting the user's profile data into the system of the invention, accumulating and saving the data in databases to enable analysis of the data, analyzing the data and identifying financial products which provide solutions to mitigate the risks. The process of the invention also includes indicting the cost to purchase the financial products for matching needs of a user to resources of a financial products provider, and for binding a commitment. Processing a transaction to implement a sale of the financial product is also part of the process of the invention.
[0013] The foregoing and other features of the present invention are more fully described with reference to the following drawings annexed hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a flow chart illustrating the process of the present invention;
[0015] [0015]FIG. 2 is block diagram illustrating the overall architecture of the system of the present invention;
[0016] [0016]FIG. 3 is a flow chart of the registration process used in the present invention;
[0017] [0017]FIG. 4 is a flow chart of the iSolve processing step of the invention;
[0018] [0018]FIG. 5 is another flow chart of the iSolve processing step in greater detail;
[0019] [0019]FIG. 6 is a flow chart of the QSolve processing step of the invention;
[0020] [0020]FIG. 7 is a flow chart of the purchasing step of the QSolve process;
[0021] [0021]FIG. 8 is a block diagram illustrating functions of the calculator used in the invention;
[0022] [0022]FIG. 9 is a flow chart of the service processing steps of the invention; and
[0023] FIGS. 10 - 18 are flow charts illustrating functional flow diagrams of scenarios of activities for the following steps respectively: login; registration; profile generation; iSolve 1 processing; iSolve 2 processing; iSolve 3 processing; QSolve 1 processing; QSolve 2 processing and QSolve 3 processing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] nuServe Processes
[0025] The overall process 10 of the invention (sometimes referred to as the “nuServe process”), as illustrated in FIG. 1, involves the following principal steps which are described in more detail below: Registration— 11 ; Input Data Entry— 12 ; iSolve Processing— 13 ; QSolve Processing— 14 ; and Service Processing — 15 .
[0026] When using the present invention, a user will navigate over the Internet to the web site where the process of the invention is accessible (the nuServe web site). After a user logs on to the site, the first step in the use of the process will be registration of the user. As noted below, a user may register in a variety of categories which will determine the level of services available to that user. The next step in the process will be the data entry step 12 , described more fully below, and generally requiring the input of data to the system for storage in the databases of the system for future reference, analysis, and calculations. iSolve processing occurs at step 13 and involves the use of the iSolve engine in order to examine the input data stored in the database for analysis and for identification of the financial risks associated with the profile of the user as indicated by the data entered, as well as for identifying financial products to provide solutions for such risks. As noted above, iSolve processing using the iSolve engine provides the capability of computing financial product values, prices and premiums for different categories of risk (sometimes referred to herein as “lines of business”). The QSolve processing step 14 is used to accomplish the function of specifying the cost to acquire the identified financial products or to provide quotations and premiums for insurance or other financial products for a particular risk category, i.e. a single line of business. The service processing step 15 includes such functions as updating the user's profile, comparing the profile to a generated portfolio, generating binder and certificate forms, and file transfer, all of which are discussed more fully below.
[0027] These steps of the nuServe process are generally carried out on the nuServe system, the overall architecture of which is illustrated in FIG. 2. A user, operating through a computing device, such as desktop computer 21 accesses the nuServe web site 23 through the Internet 22 . The web site 23 is hosted on a server 24 that supports the GUI for data entry to the Profiler 25 as well as the iSolve and QSolve engines 26 and 27 respectively used for data analysis, identification of financial products and price quotations. User data is entered to Profiler 25 through the GUI and stored on one or more databases 28 a, 28 b, 28 c, 28 d, etc., from where the data will be accessible to the iSolve and QSolve engines.
[0028] Registration
[0029] As noted above, user registration is the first step in the nuServe process. A user can register as a “Client”; a “Business”; a “Referral Customer”; or as an “Administrator and Other Staff”.
[0030] The type of registration will define the type of services that a user can receive. For example, a user with a formal registration as a Client, Business or Referral Customer should be able to use all of the services offered by the nuServe system, while a guest user without a formal registration may only be granted access to a partial list of services, such as using the GUI for Profiler data entry and iSolve processing. A registered user can never have access to the type of services that an administrator is granted. A registered user can access portal services such as reviewing news items, insurance related regulations, etc. which will be posted from time to time on the nuServe web site. A broker referred by an insurance company (registered as a Business) will have access to the many functions that other registered users have access to. Unlike the other users, a Referral Customer is required to enter a code, which indicates the customer's association with an insurance company. Such an insurance company might have special arrangements with the operator of the nuServe system.
[0031] The registration process is illustrated in FIG. 3 where a user 20 enters his registration information at step 31 into the appropriate fields displayed after log-in. The data is then reviewed by a security manager on the system server at the validation step 32 . The data is either determined to be invalid data, and step 33 feeds this back to the user so that data can be reentered, or it is determined to be valid registration data at step 34 and it is then saved in a database at step 35 .
[0032] Input Data Entry Process
[0033] The input data entry process (or Profiler Process) 12 for the system of the invention will follow a “pull” concept. That is, the user or client will be asked to enter data for a line of insurance if the user is interested in that line of business. Furthermore, the input data entry will be in phases. New users will be presented a GUI interface for data entry. By clicking the mouse at different parts of the screen different icons will pop up. For instance, a land icon would require the user to enter input data that is related to his property. This data will be entered into the appropriate fields appearing on the screen related to property. An auto icon popping up in another part of the screen would require the user to enter input data on the autos owned or leased by the user. This data can be entered into fields on a screen which will be presented by clicking on the auto icon. If an icon is of no interest to the user, he/she may choose to discard it. The user continues GUI input entry until the whole screen is filled up with different icons or until the user stops it at some point in time. In either case, the data collected from the user by entry into the appropriate fields on the GUI screen will be stored in the databases from which a user profile is created.
[0034] The input data entry could potentially be a three-phase process. The first phase of the input data entry process is described above. The information collected in the first phase is what is required to run the iSolve engine 26 or the QSolve engine 27 . Should the user decide to eventually purchase insurance or other financial products, a second phase of data entry is used where more input data will be required at the time of actual quotation. A third phase of data entry will again be required at the time of actual purchase of an insurance policy. However, the user will not be asked for these additional data until the right time in the process.
[0035] Since QSolve processing is for quick quotes on a single line of business, it naturally requires less data compared to the amount of data required for the iSolve engine to complete its processing.
[0036] Profiler—User Input Data
[0037] Upon the completion of the data entry using Profiler, the user links to a “Profiler Page” where the Profiler data will be retrieved from the databases and presented on the user's display screen. This page is a separate page from the GUI used to populate Profiler, and which was used for input data entry. The Profiler Page will be encrypted and can be used for data mining and analysis of user profiles. Because this page has significant commercial value in terms of customer data, it will be stored with a high degree of security. If the user is a non-registered guest, then its profile data together with its GUI, which includes the input data, will be stored in the databases. A guest user will be asked to enter a guest ID which will be used as an access key to the stored information. The databases will only store this information for a predetermined period of time. The guest user will be notified of this time limit.
[0038] iSolve Process
[0039] Profiler Page includes a link (which could be labeled “Get my profile”) to the iSolve engine 26 . The iSolve process can then be used to compute limits and premiums for various lines of business. The iSolve engine is programmed to accept data, evaluate risks and recommend financial solutions for a variety of categories of business risks, sometimes referred to as “lines of business” or “LOB”. Examples of such business risks that the iSolve engine can address include: Property and Business Income; Crime Coverage; Fiduciary Liability; General Liability; Boiler and Machinery; Errors and Omission Liability; Commercial Auto; Employment Practices Liability; Directors and Officers Liability; Workers Compensation; Umbrella/Excess Liability; KNR; Earthquake and Flood; Transit and Ocean Marine; Cyber Liability; Environmental Impairment Liability; and BOP.
[0040] Depending on the extent of the input data received from the user, the iSolve engine 26 will compute insurance limits and premiums on policies that mitigate these business risks. These can be categorized into the following major categories: Property; Liability; Auto; Worker Compensation; and Others.
[0041] The iSolve engine utilizes average insurance rates, established by the Insurance Service Office (ISO), incorporated and stored in the databases for the calculation of the limits and premiums.
[0042] Each category may consist of several lines of business or categories of business risks. These, together with the insurance limits and premiums for policies, or other financial products for mitigating those risks, will be tabulated on the Profiler Page generated by the iSolve engine. The Profiler Page will also include a button which the user can click on to have the iSolve engine “Update My Risk Profile”; and “Compare iSolve to my Current Portfolio.”
[0043] The iSolve processing step 13 is based upon the data entry step 12 and the user Profile which is generated by that processing step. iSolve processing is then accomplished in three stages or phases: The first phase (referred to as iSolve 1 ) is a computational process; the second phase (referred to as iSolve 2 ) is the quotation phase; and the third phase (referred to as iSolve 3 ) is the purchasing phase.
[0044] The overall iSolve process is generally indicated on FIG. 4. After the profile process of step 12 is completed the iSolve 1 step 41 is the computational process resulting in the generation of indicators (discussed below). These indicators are then used at the iSolve 2 step 51 (the second phase) for the generation of quotations or prices for the possible purchase of financial products to mitigate the assessed risks. Phase three (iSolve 3 ) of the iSolve process is completed at step 61 , which is the binding process or the purchasing phase. The purchasing phase results in the creation of a portfolio 65 . The details of the portfolio may contain information which will impact the user profile and therefore synchronization step 70 feeds back the portfolio information to the profile process 12 for possible redefinition of the profile. This will automatically result in recalculation of the indicators at step 41 and regeneration of quotations at step 51 . These phases of the iSolve processing step 13 , and the overall life cycle for the iSolve processing step is described herein below in greater detail in connection with FIG. 5.
[0045] The Profiler process 12 includes data entry 19 by user 20 , saving the input data to the databases 28 , and creating a user Profile 29 (displayed on the Profile Page) which includes risk exposures supplied at 39 from the databases. The computational phase 40 (iSolve 1 ), includes an indicator generation step 41 , to generate indicators 42 using computational models mapped into flow models and based on inputs 43 from the user 20 and inputs 44 from the databases including ISO rates, LOB's, stored indicators etc. Generated indicators 42 consist of policy premiums and policy limits depending on and related to the risk exposures. These indicators are obtained based on average ISO rates for different risks or LOB's stored in the databases. After reviewing the generated indicators, the user may decide to obtain actual quotations from insurance companies. iSolve 2 , the second phase 50 , commences at this point and consists of a quotation generation process 51 which generates a set of quotes 52 , from the databases 28 or from a third-party vendor, such as an insurance carrier or broker who will have received data about the user from the databases 28 and provides this information 54 to the quotation generation process.
[0046] The user has the ability to select quotes for all, some or only a single line of business based on that user's profile. Thus, the user can select “Quote all lines of business”; “Quote some lines of business”; or “Quote”. The “Quote” option will lead the user to the same process as QSolve for quoting a single line of business (discussed in more detail below).
[0047] Depending on the selection of the user, there will be some additional input data requirements. For the first two options above, a computational (sort and search) engine will determine the optimal product line for each line of business. For instance, for a first line of business, the engine will provide the user with the option of choosing a particular insurance provider. For a second line of business, the search engine will select the same or some other provider. In theory the search engine should be performing multi-line or multi-objective (taking into account multiple lines of business) optimization. This, however, depends on information from insurance carriers. The optimization routine will consider all applicable carriers for a line of business. For specific cases, such as PIZZA program, the product line will be privately labeled, thus restricting the optimization.
[0048] As noted above, two possibilities exist for the outcome of using the iSolve 2 process 50 : (i) quotations will be provided from the database; or (ii) quotations will be received from an insurance company or broker.
[0049] In the first case, the quotation generation process 51 will use a model for each line of business for each applicable insurance company (different insurance companies could have different ways of calculating the quotation for a line of business). In the second case, the nuServe system will send the required user data from its databases 28 to a selected insurance company for quotation. This can be transmitted either electronically or in hard copy.
[0050] Having the quotes 52 available, the user may decide to purchase one or more lines of business. ISolve 3 process 60 (the third phase) starts here. Several options are available to the user at this point. He/she can purchase a policy, or other product on line, and the user can either purchase products to mitigate all categories of risk (LOB's) or only selected LOBs.
[0051] For each line of business that the user selects to purchase a policy for, a confirmation page (or “Contract Page”) will be provided which will include profiler data and will require additional data 62 , which should be keyed in by the user (this is the third phase of input data entry). Thus the iSolve 3 process includes a binding process 61 , which may include a supplementary data entry step 62 .
[0052] If a proposed carrier for a given line of business has an agreement with the provider of the nuServe process then a temporary policy (previously loaded and saved in the database 28 ) can be made online and in real time to create part of a product portfolio 65 . Otherwise, the user will be notified of a delay as the request will have to be sent (path 68 ) to a third-party insurance carrier or to a broker. The user will also be given the option of choosing another carrier based on information 64 selected by the database 28 for which there is an agreement with the nuServe process provider and binding can be immediate. If the user decides to wait for a carrier of his/her choice, then a form (which is carrier dependent) will be prepared and will be electronically submitted after a validation process 66 to the insurance carrier or to the broker 67 .
[0053] At synchronization step 70 the active Profile 29 is modified by the user if necessary and iSolve will automatically recalculate the indicators used for quotation at iSolve 2 . The product portfolio 65 will include information that should be considered in this recalculation. The system must know if the Profile is changed. Any changes must therefore be saved by the system. Such a save function will be implemented if the user either exits the system, specifically chooses a save function, obtains a quotation or purchases a product. At synchronization step 71 the user has the opportunity to adjust or modify the Profile after viewing the indicators by inputting updated or changed Profile data. This usually occurs as a result of the user considering “what if” scenarios or hypothetical risks. When the Profile is changed iSolve 1 will recalculate the indicators. The changed Profile will automatically be saved.
[0054] QSolve Process
[0055] Should a user decide to obtain a quote for the possible purchase of and/or to purchase an insurance policy for a single LOB, the QSolve engine 27 will be the appropriate engine to use. The use of QSolve is intended for users who are familiar with various insurance policies and users who know what they want. While additional data will be required to use the QSolve process, it will not be a large amount of data. Inputting any such additional data will be through the GUI interface. However, the user will also be given the option of entering the data by simply keying the input data through an alternate simple interface.
[0056] As with the iSolve process, the QSolve processing step 14 is accomplished in phases. As seen on FIG. 6 a first phase of QSolve processing, sometimes referred to as QSolve 1 , is a rate calculation process at step 80 . This step provides a selection interface for a line of business and uses appropriate algorithms to complete the calculations. Step 81 is the second phase (QSolve 2 ) to generate indicators (i.e. policy premiums and policy limitations). Step 82 will follow step 81 for the third phase (QSolve 3 ) which performs the necessary calculations for generating quotations. The fourth phase, QSolve 4 , implements the purchasing of selected insurance policies. As will be noted, there is similarity and synergy between the iSolve processing step 13 and the QSolve processing step 14 , particularly if only a single line of business is selected for quotation and/or purchasing.
[0057] Calculating the rates at step 80 is based upon carrier rates stored in the database. Similarly, generation of the indicators at step 81 is a result of the ISO data for various lines of businesses also stored in the database. Quotation generation is also similar to quotation generation by the iSolve 2 process. The final phase of purchase may require the entry of additional data for each selected carrier and can be accomplished using the GUI or via some independent data entry technique. The purchasing process consists of three parallel steps after the data entry step 84 , as illustrated in FIG. 7. These are selecting to purchase step 85 , policy portfolio step 86 , and synchronizing step 87 for synchronizing the portfolio of step 86 with the user's original profile, in a manner similar to that discussed in connection with the iSolve processing. Completion of these steps leads to the binding step 88 for committing to the purchase and sale of the insurance product and temporary coverage.
[0058] Insurance Calculator
[0059] An insurance calculator is used both for computation of existing LOBs and for creating any new LOB, during the iSolve and QSolve processing. FIG. 8 illustrates the functional design of the calculator in which the User Input section 75 forms a matrix of LOB's and LOB Coverage. The Script Function 76 is in simple independent language and the Java Function 77 defines Java language for processing the script function where the management module 78 selects the computational script in view of the user input.
[0060] Service Process
[0061] As indicated above, additional service type sub-processes, such as indicated in FIG. 9, are available, including Update the Profile process 90 , Compare iSolve Profile to the Current Portfolio process 91 , Generate Binder and Certificate Forms process 92 , Export/Import files to/from insurance carriers and brokers process 93 , and Statistical analysis and data warehousing process 94 . These additional process are discussed in more detail below:
[0062] Update the Profile Process 90
[0063] After the iSolve process generates indications of the average insurance limits and premiums, the user/customer may decide to purchase insurance for the recommended lines of businesses. Should this be the case, database 28 will automatically update the insurance data (limits, carriers, premiums, etc.) for that user/customer. If the customer does not accept the recommendations generated by iSolve, then a record will be kept in the database indicating the recommendations made and the rejection by the customer.
[0064] Compare iSolve Profile to the Current Portfolio Process 91
[0065] To compare the portfolio generated by iSolve to the current portfolio of the user/customer, the current portfolio of the user will be needed if it is not already in the database. The user will be given the opportunity of downloading the data either by key boarding, or transferring the data from a commercially available program file, such as “Quicken.” It will also be possible for the user to fax in the portfolio. The fax will be scanned and stored into the database as the current portfolio. The comparison will be presented in the form of a table.
[0066] Generate Binder and Certificate Forms Process 92
[0067] There are industry standard forms that the database will store and that can be used for contract binding. Customized forms can also be used if preferred by a particular insurance carrier. Forms can be prepared and submitted to insurance carriers or brokers for approval.
[0068] Insurance Certificates are issued by a third party. A request for a certificate, however, can be generated by process 92 .
[0069] File Transfer Process 93
[0070] This performs the functions associated with the export of files to carriers and brokers and the import of files from carriers and brokers. Data can be transferred either as flat files, through browser-based download using standard plug-ins (e.g. Adobe Acrobat for pdf) or through specified protocols such as XML or http. Software instruction provide the flat file transfer in both directions. The following issues for database interconnectivity will determine the required software instructions: (i) How large the volume of data is (can be measured in number of records); (ii) How often the data downloading and uploading is required to be performed; (iii) The type of database access that is provided; (iv) The logical platform to be used other than a flat file; (for example, XML, or others); (v) When using manual uploading and downloading the different types of transmission media that can be used (CD-ROM, FTP, etc.); (vi) The type of protocol for administering the database when using a dedicated server; (vii) Specific data security requirements; and (viii) The need for secure HTML or XML based Internet connectivity between database 28 and the user.
[0071] Statical Analysis Process 94
[0072] The profiler page will be linked to another page where the profile obtained from the user will be compared to the statistical data retrieved from the database on the comparable industry. Two types of analysis can be performed here: (i) analysis based on the existing industry statistics, and (ii) analysis based on the data in the system databases. Criteria for analysis will be based on SIC code, number of employees, ZIP code, and revenue. For an industry based analysis, the SIC code will be used as the only criterion for the comparison.
[0073] The analysis requires that the fields corresponding to the analysis criteria can be sorted and queried. This will ensure maximum flexibility that will eventually be required for the analysis.
[0074] Other process relating to operations of the web site and administration functions can also be carried out as part of the nuServe process.
[0075] Thee are numerous materials and functional specifications maintained in the nuServe system for implementing the nuServe process. These include LOB Process Flow models on an Excel file and different classification class codes used in the General Liability and in Workers Compensation Line of Businesses. This is based on SIC codes, and other publicly available class codes including: ISO general liability class codes (CGL); California Work Comp Codes (CA, WC); Delaware & Pennsylvania Work Comp Class Codes (DE, PA, WC); Michigan Work Comp Class Codes (MI, WC); New Jersey Work Comp Class Codes (NJ, WC); Texas Work Comp Class Codes (TX, WC); NCCI Work Comp Class Codes (all other states, except for the aforementioned that contain individual codes and monopolistic states, which are not open to commercial insurers—Nevada, North Dakota, Ohio, Washington, West Virginia) (NCCI); and NAICS class codes.
[0076] The nuServe processes described above correspond to many classes of objects. Objects can be considered as logical entities encapsulating attributes and procedures (or methods). Depending on the system logic, one object can invoke one or more methods from another object. Furthermore, execution of methods in one object can be conditional on messages received from other objects. Unless constrained by the functional design of the system, the objects will be non-synchronous providing a maximal permissive system. An object model provides a logical view of a system in terms of various operations, relations and attributes or data. A scenario defines a sequence of activities and the relationship between these activities and objects. Scenarios can be used for software code preparation in order to implement functioning of the process. Accordingly, FIGS. 10 - 18 are scenarios for the following steps of the nuServe process respectively Login; Registration; Profile Generation; iSolve 1 processing; iSolve 2 processing; iSolve 3 processing; Qsolve 1 processing; Qsolve 2 processing, and Qsolve 3 processing.
[0077] The invention has been described and illustrated in connection with certain preferred embodiments which illustrate the principals of the invention. However, it should be understood that various modifications and changes may readily occur to those skilled in the art, and it is not intended to limit the invention to the construction and operation of the embodiments shown and described herein. Accordingly, additional modifications and equivalents may be considered as falling within the scope of the invention as defined by the claims herein below. | A web based system maintained at a central server and accessible to users over the Internet for defining financial risks and risk mitigation needs of a user based upon profile data of the user. The system includes a means for inputting user profile data into the system; means for accumulating the input data in databases to enable analysis of said data; and means for analyzing the profile data and for identifying financial risks associated with said profile data. The system also provides a means for identifying financial products which will provide solutions to mitigate such risks as well as a means for specifying the cost to acquire or purchase those financial products. Finally the invention includes means for binding in real time a commitment for the purchase and sale of financial products; and a means for processing a transaction to implement the purchase and sale of the financial products. | 6 |
[0001] This invention relates to information access and finds particular application in locating information contained in documents that have been annotated using a structured markup language.
[0002] To assist in locating information stored, for example, in a computer-based distributed file store, search engines of various types have been implemented in software to assist with identifying data sets that contain information of at least some relevance to a user's search criteria. To assist with information location, search engines are often able to make use of already constructed indexes to particular fields or domains of information, or to exploit summary or keyword data stored within data sets themselves.
[0003] However, it is often necessary for a search engine to analyse the contents of a data set to try to determine it's primary information content and to assess the relevance of that information to the user's requirements. This is a more or less difficult task, according to the way the information is presented and structured.
[0004] In the context of a distributed information store such as that provided by the Wordwide Web (known as the “web”), a markup language has been developed and standardised to improve identification and access to information contained in web pages. The Hypertext Markup Language (HTML) used to annotate web pages includes a <META> tag for use in identifying a list of keywords provided by the web page author and indicative of the information content of the web page. Search engines may search for a <META> tag within a web page and compare any associated keywords with a user's search criteria to determine whether or not the information in the page is likely to be relevant.
[0005] More recently, a mark-up language called extensible Markup Language (XML) has been developed to provide a more flexible and structured means for annotating information. One of the biggest potential benefits of XML is its ability to improve the accuracy of searches through the millions of documents now stored on intranets and the Internet. Exploitation of meta-information provided by XML tagging has the potential to dramatically reduce the number of irrelevant hits returned compared with current HTML-based search engines. However, whereas all tags within the HTML markup language are standardised, XML tags are, but for a small core of standard tags, entirely user-definable. To some extent, the usefulness of XML tagging is therefore subject to the skills of a document author. However, XML does allow user communities, from industry groups to single users, to develop an individual mark-up language that best suits their needs. In order to coordinate proposals for XML standards, in e-commerce applications for example, the Organisation for the Advancement of Structured Information Standards (OASIS) has created the Web Portal “XML.org”.
[0006] A known XML search engine such as “GoXML” provides a largely conventional keyword-based search facility to locate relevant information in conventional web pages as well as XML tagged documents. Where XML documents are located in a search, GoXML compiles and presents a flat list of the tags that mark up document parts within which search keywords were found, together with a conventional list of references to those documents. The user can then explore this list of “hit” tags by selecting a particular tag, causing the document list to be reduced to only those documents where a search keyword was found to occur in a part marked up by the selected tag. However, GoXML does not carry out further analysis of “hit” tags to enable a user to fully exploit the potential contextual information provided by those tags and to navigate the search results more effectively.
[0007] According to a first aspect of the present invention there is provided a method of accessing sets of information stored in an information system, wherein portions of said sets of information are enclosed by tags of a hierarchical tag structure defined according to a structured mark-up language, the method comprising the steps of:
[0008] (i) generating a search query comprising specified search criteria;
[0009] (ii) identifying portions of said sets of information matching said specified search criteria, and outputting a list of references to said identified sets of information;
[0010] (iii) identifying, for each matching portion identified at step (ii), an enclosing tag structure and outputting a list of said identified tag structures;
[0011] (iv) receiving a selection signal specifying a tag structure from the list output at step (iii);
[0012] (v) adjusting said list of references from step (ii) to comprise references only to said identified sets of information that contain the tag structure selected at step (iv);
[0013] (vi) adjusting said list of tag structures to comprise tag structures contained in information sets referenced in said adjusted list at step (v); and
[0014] (vii) repeating step (iv) in respect of said adjusted list of tag structures, and step (v) to identify a more specific list of references to sets of information.
[0015] According to preferred embodiments of the present invention, apparatus and methods are provided to enable a user to locate and retrieve sets of information relevant to search criteria specified in a search query submitted by the user. In particular, as for all embodiments of the present invention, apparatus and methods are designed to enable the user to exploit contextual information provided within documents that have been annotated using tags defined according to a structured markup language such as XML. Besides locating portions of a document that appear to match the user's search criteria, embodiments of the present invention enable the user to use XML or other markup language tags, inserted into a document by the author, to help identify those documents from a potentially large set of search results that are most relevant to the original search query or, more particularly, to what the user hoped to find.
[0016] Embodiments of the present invention are largely concerned with analysis of search results, enabling a user to exploit contextual information provided by markup language annotations in documents identified in the search. Largely conventional search engines and search techniques may be used to obtain a set of search results on the basis of a user's search query. However, the otherwise conventional search engine or other information retrieval tool must be arranged to not only to locate portions of documents matching a user's search query, but also to identify and return annotating tags associated with those matching portions, according to the particular markup language used. In particular, the structure of annotating tags used in a particular structured markup language must be identified and returned in the search results, preserving that tag structure for analysis by novel and inventive features of the present invention, to be described in detail below.
[0017] Preferably, the method of said first aspect includes the steps of:
[0018] (viii) detecting, following receipt of the selection signal at step (iv), a request for access to a corresponding set of information listed in step (v);
[0019] (ix) updating, in respect of the tag structure selected at step (iv), a weighting value representative of the probability that selection of the tag structure led to a request for access to a corresponding set of information; and
[0020] (x) outputting an ordered list of the tag structures identified at step (iii) according to their respective weighting values.
[0021] In this preferred embodiment, the method provides a further enhancement to the tag analysis process by monitoring, over a period of time, the selection of tags by users from each presented tag list and monitoring any subsequent access by a user of particular documents listed in the resultant reduced document lists. The apparatus records a history of tag selection by users in general, or by a particular user or group of users, and their subsequent document retrieval activity in respect of each distinct tag and/or tag structure. This historical data is then used to weight each of the distinct tags and tag structures according to likelihood that they resulted in a selection of documents relevant to those users. The apparatus is then able to present a given tag list in a ranking order of decreasing usefulness for example, when particular tags known from the historical records appear in a set of search results.
[0022] There now follows, by way of example only, a detailed description of specific embodiments of the present invention. This description is to be read in conjunction with the accompanying drawings, of which:
[0023] [0023]FIG. 1 is a diagram showing features of an information searching apparatus according to a preferred embodiment of the present invention;
[0024] [0024]FIG. 2 is a flow chart showing steps in operation of an information searching apparatus according to a first embodiment of the present invention;
[0025] [0025]FIG. 3 is a flow diagram showing steps in operation of a context analysis module according to a first embodiment of the present invention;
OVERVIEW OF PREFERRED EMBODIMENTS
[0026] Before describing a number of preferred embodiments of the present invention in detail, these embodiments will first be described in overview.
[0027] According to preferred embodiments of the present invention, apparatus and methods are provided to enable a user to locate and retrieve sets of information relevant to search criteria specified in a search query submitted by the user. In particular, as for all embodiments of the present invention, apparatus and methods are designed to enable the user to exploit contextual information provided within documents that have been annotated using a structured markup language such as XML. Besides locating portions of a document that appear to match the user's search criteria, embodiments of the present invention enable the user to use XML or other markup language tags, inserted into a document by the author, to help identify those documents from a potentially large set of search results that are most relevant to the original search query or, more particularly, to what the user hoped to find.
[0028] Embodiments of the present invention are largely concerned with analysis of search results, enabling a user to exploit contextual information provided by markup language annotations in documents identified in the search. Largely conventional search engines and search techniques may be used to obtain a set of search results on the basis of a user's search query. However, the otherwise conventional search engine or other information retrieval tool must be arranged to not only to locate portions of documents matching a user's search query, but also to identify and return annotating tags associated with those matching portions, according to the particular markup language used. In particular, the structure of annotating tags used in a particular structured markup language must be identified and returned in the search results, preserving that tag structure for analysis by novel and inventive features of the present invention, to be described in detail below.
[0029] Search results comprise a list of references to documents found by the search engine to have portions matching the search query, for example a list of document URLs if those documents are stored on web servers and accessible over the Internet, together with the respective tag structures associated with each of the matching portions. In each embodiment, the search results are presented to the user as a list of the identified tags and tag structures together with a list of the identified document references. For example, in a hierarchical tag structure such as that used with XML, the full structure of tags surrounding a matching portion of text will be presented in the tag list, with, optionally, a list of the lowest level tags.
[0030] In a first preferred embodiment of the present invention, a user is provided with apparatus having a user interface and facilities to enable the user to navigate through the returned set of search results making use of information provided by returned tags. In particular, a user may select one or more particular tags or tag structures from the tag list presented at the user interface and, in response to that selection, the apparatus will present at the user interface, from the set of document references, a list of only those documents containing the selected tags or tag structures associated with matching text. A user may have selected a particular tag because the words used in those tags were suggestive of a context relevant to the type of information the user was seeking. Now that the document list has been reduced the apparatus then adjusts the displayed tag list to include not only the selected tag or tags, but also any other tags and tag structures associated with matching text from the documents in the reduced list.
[0031] Identification of such additional tags may be highly relevant to the user because they may be suggestive of other contexts that might reveal relevant information, especially as those tags occurred in the same documents as the original tag selection. This so called “double filtering” technique may be extended by the user by making a further selection from the adjusted tag list and further restricting or otherwise altering the list of documents being investigated.
[0032] In a second embodiment, the apparatus provides an enhancement to the tag analysis process by using a thesaurus to identify different tags within the list that may have a similar meaning, or by using clustering techniques to identify tags that may relate to similar contexts. Such related tags may then be grouped together in the tag list presented at the user interface to enable a user to see that such tags may be so related and to providing the opportunity for the user to select the group of related tags rather than individual tags or tag structures in the “double filtering” navigation process outlined above.
[0033] In a third embodiment, the apparatus provides a further enhancement to the tag analysis process by monitoring, over a period of time, the selection of tags by users from each presented tag list and monitoring any subsequent access by a user of particular documents listed in the resultant reduced document lists. The apparatus records a history of tag selection by users in general, or by a particular user or group of users, and their subsequent document retrieval activity in respect of each distinct tag and/or tag structure. This historical data is then used to weight each of the distinct tags and tag structures according to likelihood that they resulted in a selection of documents relevant to those users. The apparatus is then able to present a given tag list in a ranking order of decreasing usefulness for example, when particular tags known from the historical records appear in a set of search results.
[0034] In a fourth embodiment, the apparatus is arranged, on the basis of previous document access by users, to establish a profile of the typical information content of portions of documents associated with each distinct tag and tag structure. Known document summarisers and key term extractors may be used to extract such profile information each time a document is accessed by a user. Typical information content of a given tag may then be made available to users as required. This helps to overcome problems in exploiting tags when lack of standardisation has resulted in different document authors using different tags or obscure choices of tag to represent the same or a similar context in particular fields of information.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] The now follows a more detailed description of preferred embodiments outlined above.
[0036] Referring to FIG. 1, an information retrieval apparatus 100 is shown according to preferred embodiments of the present invention, for use in searching for relevant information stored in file servers 105 , web servers for example, and accessible over a communications network 110 such as the Internet. The information searching apparatus is arranged to receive search queries supplied by users from terminal equipment 115 , typically submitted using a conventional browser product installed on a user's terminal equipment 115 , a web browser for example, and transmitted over the communications network 105 by means of a router 120 . The information searching apparatus 100 includes a user interface 125 for receiving search queries from users ( 115 ) and for returning search results to their terminal equipment 115 , a search engine 130 and a context analysis module 135 . Context analysis module 135 is arranged in particular to analyse and to present, via the user interface 125 , XML tag information enclosing portions of documents that were found by the search engine 130 to match the search query, in a way that enables users to exploit the contextual information provided by those tags.
[0037] Steps in operation of an information searching apparatus 100 according to a first embodiment of the present invention will now be described with reference to FIG. 2.
[0038] Referring to FIG. 2, processing begins at STEP 200 with receipt of a search query via the user interface 125 . The search query specifies search criteria, such as a set of keywords or phrases, to be used in identifying potentially relevant sets of information. At STEP 205 , the received search criteria are passed to the search engine 130 and the search engine 130 is activated to begin searching for relevant documents stored in file servers 105 . Search engine 130 may be any one of a number of different types of known search engine arranged to use the supplied search criteria in any appropriate way to identify relevant information.
[0039] If a potentially relevant document is located by search engine 130 , at STEP 210 , then at STEP 215 a reference to the located document, for example a URL if the document is a web page located on a web server, is added to search results being compiled by the search engine 130 . If, at STEP 220 , the located document is an XML document, then at STEP 225 the located document is analysed to identify a full hierarchy of XML tags enclosing a portion of the located document containing relevant information. Preferably, search engine 130 may be adapted to carry out basic XML tag identification once it has established that the located document is an XML document. Alternatively, the context analysis module 135 may identify XML tags by direct access to a document identified by the search engine 130 . Any identified XML tags are added to the search results at STEP 230 , preserving the tag hierarchy. Processing then moves to STEP 235 to determine whether all accessible documents have been searched.
[0040] If, at STEP 220 , the located document was not an XML document, or if at STEP 210 no relevant document was found, then processing proceeds directly to STEP 235 to determine whether all accessible documents have been searched.
[0041] At STEP 235 , if all documents accessible to the search engine 130 have been searched, then at STEP 240 the compiled search results are passed to the context analysis module 135 for analysis and presentation to the initiating user via user interface 125 . If documents remain to be searched at STEP 235 , then processing returns to STEP 205 to continue the search for relevant information.
[0042] The context analysis module 135 may be arranged to provide a number of particularly useful functions, exploiting any contextual information provided by XML tags, to assist a user in navigating and selecting from a set of search results. Such functions are of particular use when search results contain a great many “hits” in response to a particular search query. Further embodiments of the present invention, to be described below, relate to the different levels of functionality that may be provided by the context analysis module 135 .
[0043] According to the first embodiment of the present invention, context analysis module 135 provides a basic tag listing and grouping facility, accessible to users via the user interface 125 , preserving and displaying a hierarchy of tags where more than one level of tagging was detected in a particular document. This enables search results to be grouped and selected by users for further examination according to tag group, the assumption being that tags of the same or a similar name are indicative of a similar information context. This basic tag listing and grouping function of context analysis module 135 will now be described with reference to FIG. 3.
[0044] Referring to FIG. 3, context analysis begins at STEP 300 with receipt from the search engine 130 of a set of search results. At STEP 305 , all the XML tags identified in the search results are selected and an ordered list of XML tags is generated, preserving the hierarchical structure of tags where there is more than one level enclosing a relevant section of a document. At STEP 310 , for each distinctly named tag and tag hierarchy, a count is made of the number of document references from the search results in which the same tag or tag hierarchy was identified. At STEP 315 , the ordered tag list and associated document count is presented to the originating user via the user interface 125 . At STEP 320 , in addition to the tag list, a list of all the identified document references is also presented via the user interface 125 in a conventional format, for example including a document address or other reference together with, if enabled, a precis of the relevant section of each document.
[0045] At STEP 325 , the context analysis module 135 is arranged to accept, via the user interface 125 , user selection of any tag or group of tags from the displayed tag list, or selection of an option to exit. If the user does not want to exit, at STEP 330 , then at STEP 335 the list of document references is adjusted to show references for only those documents in which one or more of the selected tags were found by the search engine 130 . So, for example, if there were found at STEP 310 to be 17 documents in which a relevant portion was contained within an XML tag <PRODUCT_TYPE>, then if <PRODUCT_TYPE> were selected from the tag list at STEP 325 , the user would then see at STEP 335 those 17 document references listed via the user interface.
[0046] Having presented the adjusted list of document references at STEP 335 , the tag list itself is then adjusted at STEP 340 to display only those tags identified in those documents referenced in the adjusted document list. This adjustment to the tag list may bring in extra tags that were not selected at STEP 325 because in one or more of the documents containing the selected tag(s), the search engine 130 may have identified more than one potentially relevant portion, each portion being enclosed by different tags. This additional tag information can be very useful when navigating through the search results because the adjusted tag list is more likely to contain tags related in context (at least from the point of view of the user submitting the original search query) given that they occurred within documents located using the same search query. When processing returns to STEP 325 the user may select one or more of those additional tags and hence, at STEP 335 , identify and view any further documents containing potentially relevant portions in the context of those additional tags.
[0047] In this way, a user may use the tag list to “drill-down” to those documents most likely to contain relevant information by navigating through tags that appear to suggest the most relevant context. Adjustment of the listed document references and, in response, to the listed tags to correspond to the listed documents, provides a double filtering mechanism that is particularly effective in helping a user to navigate through search results and select a potentially relevant subset of documents for further investigation, making full use of contextual information provided by XML tags.
[0048] At any stage, a user may expand analysis of the search results by restoring the full list of displayed tags and selecting another starting point.
[0049] Further basic sorting facilities may be provided by the context analysis module 135 according to the first embodiment. In particular, a so called “stop list” may be used by the context analysis module 135 to eliminate particularly basic XML tags from consideration and display in a tag list. Such tags might include <CHAPTER>, <SECTION>, <PARAGRAPH>, <WORDS> and other such tags that provide only structural information about the layout of a document and little about the informational context of a portion identified by the search engine 130 .
[0050] However, tags such as <SUMMARY> or <PRECIS> provide useful information about the context, within the document, of a matching word or phrase, suggesting that the matching word or phrase is more likely to be indicative of the primary information content of the document as a whole. Whether stop lists are used in relation to a particular information search is preferably an option selectable by a user via the user interface 125 .
[0051] According to a second preferred embodiment of the present invention, there is provided and an apparatus and method for enhancing the analysis and interpretation of tags and tags structures returned in search results to assist a user in recognising groups of tags having a similar meaning or relating to a similar context.
[0052] XML tags in particular are simply words. Aside from those that are standardised for XML itself, different words may be used in different XML implementations to mean largely the same thing. One author might tag part of a document as <summary> while another might tag the same part of another document as <precis>; or a section of one document might be about software agents and tagged <agents> while in another document the same tag is used to tag a section about estate agents.
[0053] According to the second preferred embodiment of the present invention, the context analysis module 135 is provided with access to a thesaurus for use in identifying synonyms and helping to disambiguate tags. A general purpose thesaurus may be used, for example one such as WordNet, as disclosed in “WordNet: An Electronic Lexical Database”, edited by Christiane Fellbaum, MIT Press, May 1998., or, for more specialised information searches, a ready-made domain-specific thesaurus may be accessed, or even created using a clustering technique—see below.
[0054] Preferably, in presenting search results using tags lists as described above with reference to FIG. 3, the context analysis module 135 may present tags in a list along with identified synonyms from the thesaurus to help clarify the context of the tag. Alternatively, tags found to be related in meaning, following reference to the thesaurus, may be grouped together in the presented tag list to enable a user to select the whole group when narrowing down the list of documents to be investigated.
[0055] In addition, or alternatively to the use of a thesaurus, clustering techniques such as those disclosed in “Clustering Algorithms”, Rasmussen, E., in “Information Retrieval: Data Structures and Algorithms”, edited by Frakes, W. & Baeza-Yates, R.,Prentice-Hall, New Jersey, USA, 1992, may be used to identify tags having a similar meaning or used in a similar context in the returned search results.
[0056] A numerical value representative of a measure of the contextual ‘similarity’ of a pair of tags Ti and Tj returned in the search results, may be calculated as:
2 *[Ti∩Tj]/[Ti]+[Tj]
[0057] where [Ti] and [Tj] are the number of documents in the search results in which tags Ti and Tj respectively were identified in relation to relevant information, and
[0058] [Ti∩Tj] is the number of documents in which Ti and Tj co-occur. This measure of similarity takes a value between 0 and 1, with 0 meaning that the tags share no similarity of context (no documents contain both the tags) and 1 meaning that all documents in the search results contain both the tags and hence that the two tags are likely to have been used in the same information context.
[0059] A matrix of values for the above measure of context similarity is calculated for the tags and tag structures returned in a given set of search results. This matrix may then be used to identify groups of tags that may be related in context, for example by identifying a set of tags for which each combination of two tags selected from the set has a value of the similarity measure exceeding a predetermined threshold. The most similar tags may then be presented in groups for selection by a user in the tag list.
[0060] According to a third preferred embodiment of the present invention there is provided an apparatus and method for monitoring tag selection and associated document access by individual users or by predetermined groups of users as the basis for weighting and ranking distinct tags. Weightings may represent the probability that a given tag or tag structure will result in a selection of documents from the search results that contains documents of relevance to the particular user or group of users.
[0061] The apparatus of the third embodiment is provided with an information access monitor for monitoring selection of tags and access to referenced documents by users. The information retrieval monitor is arranged with access to the user interface 125 to monitor all tag selections by users and any requests by users to access documents included in corresponding lists. The monitor also includes a store for recording history of selection for each distinct tag and tag structure and for recording weightings calculated in respect of each tag.
[0062] Each time a user selects a tag from a tag list presented at the user interface 125 , the monitor checks for an entry in the store for that particular tag. If not, then an entry is created for the tag. If necessary, certain “low value” words may be removed from the stored tag, or words may be stemmed to render them into a more standardised form. For each tag, a counter is maintained both for the number of times that selection of the tag was selected and for the number of times that selection of the tag was followed by an access request by the user for a document listed in the resultant reduced document list (see STEPs 325 and 335 of FIG. 3). These counters may then be used to calculate, for each tag, a weighting representing a measure of the probability that selection of the tag results in a list containing relevant documents for that user.
[0063] The monitor may be further enhanced to monitor the duration of a document access by a user, providing further information on the relevance of the accesses document to the user. Longer duration access to documents may trigger a double increment, for example, of the second of the two counters mentioned above.
[0064] Operation of the information retrieval monitor described above may be triggered each time a new set of results is returned in response to a search query and the initial tag list is presented at the user interface 125 . Weightings may be recalculated each time a user accesses a document so that they are immediately available for use in ranking each presented tag list.
[0065] In an alternative ranking method, a user profile of keywords or terms may be stored in respect of each user of the apparatus. Such a profile may be used to represent the interests of a user and particularly contextual information of relevance to that user's interests. A known measure of relevance may be calculated for each tag in a tag list with respect to the words and terms in the user profile. The measure of relevance may be used to rank the tags in the list in order of relevance to the user profile as a further assistance to a user in selecting tags most likely to result in an efficient navigation of a set of search results leading to a list of the most relevant documents from the search.
[0066] According to a fourth preferred embodiment, known document summarisers and key term extractors may be used to accumulate a profile of information content typically associated with each of a set of distinct tags, for example the tags stored by the information retrieval monitor of the third embodiment described above.
[0067] Each time a user accesses a particular document, key terms indicative of the information content of the matching portion of that document may be extracted and stored in association with the particular tag selection that preceded access of that document. Such terms may be further summarised to build up a profile of a tag for presentation to users as required. This feature provides further assistance to users in understanding the intended meaning of a tag, particularly in the absence of standardised use of tags. | According to the present invention, apparatus and methods are provided to enable a user to locate and retrieve sets of information relevant to search criteria specified in a search query submitted by the user. Search results include not only a list of information sets matching with the search criteria, but also the preserved structure of any tags used in annotating the information set according to a structured mark-up language such as XML. A user may select a tag from a presented list of the returned tag structures, and the apparatus lists those documents containing the selected tags. The list of tags is then adjusted to include the selected tag and any other of the returned tags contained in the listed documents. Further tag selection from the adjusted list leads to a further refinement of the listed documents, enabling the user to navigate the search results on the basis of tag information. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a co-owned divisional application of parent application Ser. No. 11/551,155, titled “Massive Security Barriers Having Tie-Bars in Tunnels”, filed Oct. 19, 2006 and issued as U.S. Pat. No. 7,654,768. This divisional patent application also relates to the simultaneously-filed co-pending and co-owned divisional patent application titled “Segmented Massive Security Barriers Having Tie-Bars in Tunnels”, application Ser. No. 12/618,701, filed Oct. 13, 2009 and issued on May 24, 2011 as U.S. Pat. No. 7,946,786, the disclosure of which is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to passive barriers located on the ground and interconnected to establish a longitudinal wall that can provide security from terrorist threats by at least slowing, and preferably stopping in a short distance, a vehicle that collides with it, and by providing at least partial protection against blast wave forces, thermal energy, and flying debris from a nearby explosion event.
2. Description of the Related Art
Security zones for protecting sensitive groups of people and facilities be they private, public, diplomatic, military, or other, can be dangerous environments for people and property if threatened by acts of terrorism. Ground anchored active anti-ram vehicle barriers, bollards, and steel gates may stop a vehicle but may do little against a blast wave or blast debris. Earthen berms, sand-filled steel walls, massive concrete or plate steel walls anchored into the ground, or concrete panels laminated with steel sheeting and anchored into the ground have been used to shield against both terrorist vehicles and bombs. But none of these ground-anchored barriers are portable for ease of relocation, and all risk the possibility of interfering with underground utilities and other underground hazards.
However, both U.S. Pat. No. 7,144,186 to Roger Allen Nolte titled “Massive Security Barrier” and U.S. Pat. No. 7,144,187 to Roger Allen Nolte and Barclay J. Tullis titled “Cabled Massive Security Barrier”, both incorporated herein by reference in their entireties, disclose barriers that are portable for ease of relocation and do not endanger underground utilities when being deployed, installed, or removed. U.S. Pat. No. 7,144,186 discloses barriers, each with at least one rectangular tie-bar of steel cast permanently within concrete or other solid material and extending longitudinally between opposite sides of the barrier, wherein adjacent barriers are coupled side-against-side by means of strong coupling devices between adjacent tie-bars, and wherein no ground penetrating anchoring means is involved. But since the tie-bars are cast within the barriers, they cannot be changed out or upgraded without removing and replacing the solid material as well. U.S. Pat. No. 7,144,187 discloses barriers of solid material with tunnels extending between opposite sides, wherein adjacent barriers are coupled side-against-side with cables passing through the tunnels and anchored to sides of at least some of the barriers by anchoring devices. But since cables through tunnels between adjacent barriers are less able to resist lateral displacement between adjacent barriers compared to that when using rigidly coupled tie-bars, the use of cables limits the relative shortness of stopping distance that a wall can achieve, where stopping distance is the maximum distance any portion of a wall moves before all the kinetic energy causing an external force is absorbed.
U.S. Pat. No. 6,474,904 to Duckett et al. titled “Traffic Barrier with Liquid Filled Modules”, although not in the field of massive security barriers for protection against terrorist threats, discloses a traffic barrier design that uses a attachment members (similar in some respects to a tie-bar) through a tunnel within a cavity shaped by a plastic shell of a module body for containing water or other fluid. Duckett et al. also uses abutment members to constrain longitudinal positions of tie-bars relative to module bodies, but not relative lateral positions. However, Duckett et al. does not disclose or suggest the use of a massive block of solid material, the coupling of massive blocks side-against-side, the enablement of mutual rotation between adjacent blocks caused by a colliding vehicle or explosive blast sufficiently strong as to cause breakage of portions of the blocks that interfere with such rotation while at the same time maintaining continuity of and between coupled tie-bars, or the use of tunnels with entrance sizes closely matched to tie-bar sizes to constrain the positions of coupled ends of tie-bars relative to barrier blocks. And Duckett et al. doesn't disclose or suggest the use of side cavities to protect or constrain coupling devices and/or their retainers.
What is needed is a massive-security-barrier wall system made of massive security barriers that can be coupled into a row along the ground or other supporting surface, wherein each barrier has at least one strong tie-bar passing through it from one side of the mass of solid material of the barrier to its opposite side, wherein adjacent barriers are interconnected side-against-side by coupling the tie-bars between those adjacent barriers, wherein the tie-bar(s) of each barrier are constrained longitudinally and horizontally by the mass of solid material of that barrier to resist lateral displacement between adjacent barriers, and wherein the tie-bars can be selected at the time barriers are assembled into a barrier wall. What is needed also is the capability of exchanging or upgrading tie-bars in the field without having to replace the masses of solid material, and without the additional cost of scrapping that material. In other words, what is needed is a massive security barrier system that uses tie-bars through masses of solid material without having the tie-bars cast into the masses of solid material. The current invention provides such a system with such barriers.
BRIEF SUMMARY OF THE INVENTION
The invention is pointed out with particularity in the appended claims. However, some aspects of the invention are summarized herein.
The invention includes a massive security barrier module, a security wall, and a method of providing security from a terrorist threat, the method by the assembly of massive security barriers to form a security wall. The invention improves over the prior art by combining into a massive security barrier at least one tie-bar through at least one tunnel, wherein the tunnel penetrates through the mass of solid material (also called a block or barrier block) of the barrier. The invention uses coupling devices, and retainer devices as well in some embodiments, to both retain a tie-bar to a barrier block and to couple barrier blocks together side-against-side. A security wall is constructed by coupling or otherwise linking two or more such massive security barriers side-against-side to form a longitudinal wall that can provide security from terrorist threats by being able to withstand both vehicle collisions and explosive blasts that can provide sufficient external force to a) cause at least a portion of such a wall to slide across the ground or other supporting surface and b) if sufficient force is applied to break away interfering material, to cause at least some adjacent barriers to rotate relative to one another and not become uncoupled from one another. Each massive security barrier includes a mass of solid material having a slidable bottom surface, two opposite side surfaces each with at least one cavity, one or more tunnel passages extending through the mass of solid material between its opposite sides, and one or more tie-bars (also called metal beams) each having two opposite ends spaced longitudinally apart positioned in at least one of the tunnels with the two opposite ends extending respectively outward into two of the cavities. The mass of solid material is of durable material and preferably of high strength concrete. Each tie-bar is preferably made of high strength steel and typically has a cross-sectional area greater than that of an ordinary rebar rod used to reinforce concrete structures. Multiple blocks as described can be positioned on top of the ground, road-surface, parking surface, or other supporting surfaces, and coupled longitudinally to one another, with tie-bars end-to-end, and with adjacent barrier blocks side-against-side to establish a protective barrier wall. Within this disclosure, the term “end-to-end” should be taken to mean any of the following: truly end-to-end, butt-end-to-butt-end, generally end-to-end, end-overlapping-end, having interleaved ends, approximately end-to-end, or any other equivalent structural relationship that permits two tie-bars to be joined together near one each of their ends, extends their overall combined length, and provides a combined structure that will support tension and compression forces longitudinally and shear forces laterally. The coupling devices that serve as means for coupling can be, or (in some embodiments) retainer devices (also called retainers) that function as means for retaining are, sized relative to the sizes of tunnel entrances to block the coupling devices from entering the tunnels, i.e. they can prevent longitudinal translation of tie-bars within a barrier. Either or both a) the sizes of coupling devices (and separate retainer devices when used) relative to the sizes of the cavities or b) the sizes of the cross-sections of the tie-bars relative to the entrances of the tunnels, horizontally constrain lateral translation at locations within the blocks. Such a wall can withstand great longitudinal tension and can absorb and endure great amounts of mechanical and thermal energy. When loaded laterally (and horizontally), such as by forces from a nearby explosive blast or by a collision from a moving vehicle, such a wall can act at least initially as a structural beam, with at least one chain of tie-bars in tension, and with the solid material (e.g. concrete) in compression on the side of the wall facing the blast or vehicle. With sufficient tensile strength in a chain of tie-bars as the wall changes its shape by moving over the ground, vertical edges of the solid material (i.e. front or rear portions of the sides of blocks) in compression can be designed to fail by absorbing significant energy, and as a result, adjacent barriers can rotate or hinge relative to one-another as their inter-coupling devices swivel or the tie-bars near the couplings bend.
One of the embodiments of the invention is a method for providing protection from a terrorist threat, the method comprising: a) aligning multiple barriers into a row between an expected safe side and a threat side, wherein each barrier is aligned side-against-side with another of the multiple barriers to form an adjacent pair respectively; and b) using means for coupling and means for retaining to couple and retain each adjacent pair in the row; wherein the row extends longitudinally from a first barrier to a second barrier; wherein each of the barriers comprises a mass of solid material and a tie-bar; wherein each mass of solid material comprises two opposite sides, two cavities with one in each of the two opposite sides, and a tunnel through the mass of solid material between the two cavities; and wherein each of the barriers further comprises a tie-bar that extends through the tunnel of that barrier and has two end-portions each of which penetrates at least a portion of one of the two cavities of that barrier; whereby at least all excepting the first and second barriers of the row have sufficient strength to remain coupled throughout a terrorist event that is one selected from the group consisting of a colliding terrorist's vehicle and a terrorist's explosive blast; and whereby forces from the terrorist event can be strong enough to cause at least some of the coupled barriers to slide across a supporting surface, and can cause breakage of solid material where the solid material interferes with rotation between adjacent barriers. The method can further comprise using means for coupling and means for retaining, to retain each of the first and second barriers. The general shape of a lateral cross-section of a tunnel can be any shape that will accommodate a tie-bar, e.g. circular, elliptical, oval, square, rectangular, polygonal, multi-sided, and irregular. A tunnel should be large enough that a tie-bar extending though it can be at least wiggled to adjust its position relative to a tie-bar of an adjacent barrier with which it is to be coupled. At least one instance of the means for retaining can be located between an instance of the means for coupling and one of the tunnels. And an instance of means for coupling can itself serve also as an instance of means for retaining
According to one aspect of the above embodiment, at least one instance of means for coupling can be comprised of a pin or a bolt, wherein at least two of the end portions coupled by the means for coupling each includes a hole that receives the pin or bolt. And at least one tie-bar can have a laterally larger cross-sectional area in at least one of its end portions than along its mid-portion, and wherein at least one instance of means for coupling comprises an enclosure that laterally encircles that end portion and obstructs it from being pulled out of the enclosure.
Another embodiment of the invention is a security wall comprising: a) a row of coupled barriers, each barrier comprising respectively: i) a mass of solid material that comprises two opposite sides, two cavities with one in each of the two opposite sides, and a tunnel through the mass of solid material between the two cavities, and ii) a tie-bar that extends through the tunnel and has two end-portions each of which penetrates at least a portion of a respective one of the two cavities; wherein each barrier is aligned side-against-side with another of the multiple barriers to form an adjacent pair; and b) for each adjacent pair an instance of means for coupling the tie-bar of one of the barriers of that adjacent pair to the tie-bar of the other barrier of that adjacent pair, and for each adjacent pair at least one instance of means for retaining in one of the cavities between the barriers of that adjacent pair for retaining the instance of means for coupling from entry into the tunnel that opens into said one of the cavities; whereby the coupled barriers have sufficient strength to remain coupled throughout a terrorist event that is one selected from the group consisting of a colliding terrorist's vehicle and a terrorist's explosive blast; and whereby forces from the terrorist event can be strong enough to cause at least some of the coupled barriers to slide across a supporting surface, and can cause breakage of solid material where the solid material interferes with rotation between adjacent barriers. The security wall can be further comprised of: a) at least two additional instances of means for coupling; and b) at least two additional instances of means for retaining; wherein the two additional instances of means for coupling and the two additional instances of means for retaining are installed at ends of the row. The general shape of a lateral cross-section of at least a portion of at least one of the tunnels can be at least approximately one selected from the group consisting of circular, elliptical, oval, square, rectangular, polygonal, multi-sided, and irregular; and wherein the cross-sectional area of that tunnel can be large enough that of the tie-bar extending through that tunnel can be wiggled within that tunnel. A tunnel should be large enough that a tie-bar extending though it can be at least wiggled to adjust its position relative to a tie-bar of an adjacent barrier with which it is to be coupled. At least one of the instances of means for retaining can be located between one of the instances of means for coupling and one of the tunnels. And at least one of the instances of means for coupling can comprise one of the instances of means for retaining
According to one aspect of the above embodiment, at least one of the instances of means for coupling can be comprised of a pin or a bolt, and wherein at least two of the end portions coupled by the element each includes a hole that receives the pin or bolt. And at least one tie-bar can have a laterally larger cross-sectional area in at least one of its end portions than along its mid-portion, and wherein at least one instance of means for coupling comprises an enclosure that laterally encircles that end portion and obstructs it from being pulled out of the enclosure.
Another embodiment of the invention is a massive security barrier module comprising: a) a mass of solid material having a slidable bottom surface, wherein the mass has two opposite sides, a front, and a back, wherein each side has a front edge near the front, wherein each side has a back edge near the back, wherein each of the two opposite sides each contains one of a pair of opposite cavities, and wherein at least one tunnel extends between the pair of opposite cavities and through the mass; b) at least one tie-bar extending through the tunnel and into the cavities; c) means for coupling the tie-bar to other tie-bars of similar and adjacent massive security barrier modules, the adjacent massive security barrier modules being side-against-side with said massive security barrier module, and the other tie-bars retained at sides that are remote from the sides of said massive security barrier module; and d) means for retaining the means for coupling from entry into the tunnel; whereby the massive security barrier module has sufficient strength to maintain attachment with the adjacent massive security barrier modules when said massive security barrier module is subjected to an external impulsive force from a terrorist act sufficiently strong to rotate the modules relative to one another and cause at least one of the edges that structurally interferes with that rotation to break; and whereby energy from a security-threat event is absorbed by the break and further attenuated by the bottom surface of said massive security barrier module sliding across a supporting surface. And at least one instance of the means for coupling can comprise an instance of the means for retaining. At least one instance of the means for coupling can be comprised of a pin, a bolt, or an enclosure. Another embodiment of the invention is similar to the massive security barrier module described above in this paragraph, except that said mass of solid material is comprised of at least two individual segments that key into one another, and only one of which includes the tunnel for the tie-bar, wherein the tie-bar can be cast within the other of the two segments without requiring a tunnel; whereby the segments of the module can be handled and shipped independently.
OBJECTS AND ADVANTAGES OF THE INVENTION
Objects and advantages of the present invention include a security barrier that is massive, durable to vehicle collisions, durable to explosive blasts, energy absorbing, portable, inexpensive to manufacture, inexpensive to deploy, inexpensive to upgrade or downgrade with changes in tie-bars, inexpensive to relocate, inexpensive to remove, able to be firmly coupled to adjacent barriers, able to transfer rotational forces to adjacent barriers, able to transfer longitudinal tension forces to adjacent barriers, able to transfer compressive forces to adjacent barriers, resistant to rolling, resistant to sliding, has a high coefficient of friction with the ground (or other supporting surface), available in a variety of architectural designs and surface appearances, providing of mounting fixtures for flags and cameras and the like, providing of chases or conduits for utilities, and non threatening to utilities located below the ground.
The same objects and advantages of the invention that apply to a single barrier extend to barrier walls constructed by coupling adjacent barriers to one another in a longitudinal side-against-side row of barriers. Parts of the invention and its preferred embodiments include means for coupling tie-bars end-to-end.
The barriers can be transported by truck, positioned at a security site by using readily available heavy lifting equipment, and can be longitudinally inter-connected by means of field-installable mechanical coupling hardware. The invention does not require ground-penetrating anchoring devices, so installation, relocation, and later removal does not endanger underground utilities. And since the tie-bars are not cast into concrete or other solid material of the barriers, but rather are positioned in at least slightly larger tunnels within the concrete or other solid material of the barriers, the tie-bars can be wiggled within the tunnels to better enable alignment with adjacent tie-bars of neighboring barriers, can be selected at the time of installation for strength capability, and can be repaired, upgraded, or otherwise replaced in the field without having to scrap any mass of solid material. Another advantage of the invention is that cables can optionally also be passed through the tunnels to be used as a secondary strength system in case a tie-bar fails, and this would permit such a wall to be pushed still farther from its initial position but remain a connected barrier.
Further advantages of the present invention will become apparent to the ones skilled in the art upon examination of the drawings and detailed description. It is intended that any additional advantages be incorporated herein.
The various features of the present invention and its preferred implementations may be better understood by referring to the following discussion and the accompanying drawings. The contents of the following discussion and the drawings are set forth as examples only and should not be understood to represent limitations upon the scope of the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing objects and advantages of the present invention for a massive security barrier and security wall of such barriers (and its method of assembly) may be more readily understood by one skilled in the art with reference being had to the following detailed description of several embodiments thereof, taken in conjunction with the accompanying drawings. Within these drawings, callouts using like reference numerals refer to like elements in the several figures (also called views), alphabetic-letter-suffixes where used help to identify copies of a part or feature related to a particular usage and/or relative location, a single prime can denote a part or feature at an opposite location relative to an un-primed part or feature respectively, a numeric suffix following an alphabetic-letter-suffix denotes a modification to a part, and a double (or more) prime as an only suffix also denotes a modification to a part. Within these drawings:
FIG. 1 shows a perspective view of two massive security barriers, one on the left and the other on the right in the view, coupled together side-against-side to form a short massive security wall.
FIG. 2 shows an enlarged view of the barrier on the left from the view shown in FIG. 1 .
FIG. 3 shows a perspective view of three massive security barriers coupled together side-against-side to form a security wall.
FIG. 4 shows a perspective view of four massive security barriers coupled together side-against-side to form a security wall that has some of its vertical edges damaged but remains secured together.
FIG. 5 shows a barrier without the presence of coupling hardware or retainer hardware, revealing tie-bars within tunnels within a block or mass of solid material.
FIG. 6 shows a barrier with the presence of retainer hardware but without the presence of coupling hardware.
FIG. 7 shows a first example of means for retaining that is a retainer which can be used to prevent one or two coupling devices near the ends of two tie-bars in a common barrier block from entering either of two tunnels in the barrier.
FIG. 8 shows a second example of means for retaining that is a retainer which can be used to prevent one or two coupling devices near the ends of two tie-bars in a common barrier from entering either of two tunnels in the barrier.
FIG. 9 is a sectional view from FIG. 1 showing means for coupling and means for retaining, wherein a coupling device and two retainers are used to couple the two barriers together sides-against-side with the tie-bars of one barrier positioned end-to-end respectively with the tie-bars of the other barrier.
FIG. 10 is similar to FIG. 9 , but wherein the two retainer devices are not being used.
FIG. 11 is similar to FIG. 9 , but wherein the two retainer devices have added features with which to fill at least some of the otherwise empty space between the coupling device and the nearest sides of the barriers.
FIG. 12 is a perspective view showing a tie-bar with an oval-shaped hole near each of its ends.
FIG. 13 is a close-up view of one of the ends of the tie-bar shown in FIG. 12 .
FIG. 14 is a perspective view of an end of a tie-bar that has it's thickness increased relative to the mid-portion of the tie-bar.
FIG. 15 is a front view showing one example of means for coupling two tie-bars end-to-end.
FIG. 16 shows a perspective view of two parts of an opened enclosure device that can be used to couple two tie-bars end-to-end.
FIG. 17 shows a perspective view of the enclosure of FIG. 16 closed about the ends of two tie-bars and thus serving as means for coupling the two tie-bars together.
FIG. 18 shows an enlarged view of the barrier as seen on the left in FIG. 1 , only its mass of solid material is modified to be comprised of two individual segments that key into one another.
FIG. 19 shows one of the segments of the barrier of FIG. 18 , designed with tunnels for tie-bars.
FIG. 20 shows a modified version of the segment of barrier shown in FIG. 19 , designed without tunnels and having tie-bars cast in place within the segment.
DETAILED DESCRIPTION OF THE INVENTION
The following is a detailed description of the invention and its preferred embodiments as illustrated in the drawings. While the invention will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.
FIG. 1 shows a perspective view of one embodiment of the invention, that being two massive security barriers 113 A and 113 B adjacent to one another, the massive security barrier 113 A on the left and the massive security barrier 113 B on the right in the view, coupled together side-against-side into a coupled pair of massive security barriers 101 to form a short security wall 103 . (Two massive security barriers adjacent to one another are referred to herein as an adjacent pair, independent of whether they are coupled or not.) The barriers 113 A and 113 B are sitting on top of a supporting surface such as a ground surface 135 . One skilled in the art should appreciate that such a supporting surface could be, for example, the ground surface of a lawn, the surface of an open field, the surface of a parking lot, the surface of a roadway, the surface of a shoulder of a roadway, the surface of a plaza, etc. In this embodiment, the massive security barrier 113 A is comprised of a mass of solid material 111 A and two tie-bars ( 161 A and 163 A called out in the cross-sectional view of FIG. 9 ) whose left-hand ends 121 A and 123 A are visible in this view. Also, the massive security barrier 113 B is comprised of a mass of solid material 111 B and two tie-bars ( 161 B and 163 B called out in the cross-sectional view of FIG. 9 ). It should be appreciated by one skilled in the art that other embodiments of the invention could be comprised of only one tie-bar per barrier, or more than two tie-bars per barrier. It should also be appreciated by one skilled in the art that other embodiments of a security wall by the invention can be comprised of a row of multiple barriers preferably numbering greater than merely the two illustrated.
In regard to FIG. 1 , the mass of solid material 111 A has two opposite sides 129 A and 129 A′, and the mass of solid material 111 B has two opposite sides 129 B and 129 B′. The two masses of solid material 111 A and 111 B are shown adjacent to one another with sides 129 A′ and 129 B against one another (i.e. at least nearly touching one another) thereby defining an interface region 115 . Within each side of each barrier is a cavity into which the one or more tie-bars associated with that barrier penetrate. The mass of solid material 111 A of barrier 113 A has cavities 117 A and 117 A′. The mass of solid material 111 B of barrier 113 B has cavities 117 B and 117 B′. Tie-bar ends 121 A and 123 A are visible in this view extending into cavity 117 A at the far left of the view. In cavity 117 A at the left end of the security wall 103 , a coupling pin 171 A is visible along with its head 173 A. The coupling pin 171 A extends through both tie-bar ends 121 A and 123 A, through holes 131 A (not visible in this view, but visible in FIGS. 5 , 6 , and 12 ) in the upper tie-bar 121 A and 133 A in the lower tie-bar 123 A.
In regard to FIG. 1 , holes such as hole 133 A are in both ends of each tie-bar and are oval shaped with extension parallel to the length-wise dimension of its corresponding tie-bar. Such extensions can accommodate deviations in the accuracy of the placement of the holes when inserting a coupling pin (such as coupling pin shown with head 173 in this view between the two barriers 113 A and 113 B) during installation of a security wall (such as 103 ). These oval shaped holes are also used to alleviate tension between coupled tie-bars during the very initial interaction between coupled barriers when a security wall of which the barriers are apart is first struck by a moving vehicle, a period in time during which the security wall begins to change shape as barriers begin to slide across the supporting surface 135 and as some of the masses of solid material that interfere with mutual rotation of adjacent barriers begins to break away.
In regard to FIG. 1 , also visible is a retainer 149 A that both tie-bars with ends 121 A and 123 A extend through. In cavity 117 B′ at the right end of the security wall 103 , the head 173 B′ is visible of coupling pin 171 B′ (the body of pin 171 B′ is not visible in this view) along with a retainer 149 B′, both in a similar arrangement as the coupling pin 171 A and retainer 149 A shown at the left end of the security wall 103 , only attached to the tie-bars of barrier 113 B instead. Within the interface region 115 , the cavity 117 A′ of barrier 113 A and the cavity 117 B of barrier 113 B together form a combined cavity 119 between these adjacent barriers 113 A and 113 B. Within this combined cavity 119 , the head 173 of a coupling pin 171 (pin 173 is not visible or labeled in this view but is visible and labeled in the sectional view of FIG. 9 ) and two retainers (not labeled in this view but labeled in the sectional view of FIG. 9 as 149 A′ and 149 B) are visible. Note that the head 173 of coupling pin 171 , and the coupling pin 171 itself (the pin coupling the two barriers 113 A and 113 B together in the interface region 115 and visible in FIG. 9 ), could each alternatively be labeled with a suffix of A′ or B because they can be considered as either the coupling pin at the right-hand side of the left barrier or the coupling pin at the left-hand side of the right barrier. It will be readily appreciated by one skilled in the art that after completion of installation of a security wall such as 103 , it is advisable to protect the otherwise exposed tie-bar ends and means for coupling (and means for retaining if used) with protective covers and/or sealing means to conceal the presence of the cavities, discourage tampering, and keep out rain and snow.
FIG. 2 shows an enlarged perspective view of the massive security barrier 113 A as it might be configured for storage, shipment, or handling before being connected to one or two other barriers. All that is shown in this view is also shown in FIG. 1 with one exception being that FIG. 2 shows callouts for a top surface 141 A, a bottom surface 143 A, a front surface 145 A, and a back surface 147 A of the mass of solid material 111 A of barrier 113 A. Another exception is that FIG. 2 also shows outer vertical edges 151 A, 153 A, 151 A′, and 153 A′ formed at the intersections of the side surfaces 117 A and 117 A′ with the front surface 145 A and the back surface 147 A. Another exception is that FIG. 2 shows at the right of the view the head of a coupling pin with a callout of 173 A′ instead of 173 as it would be labeled if shown connecting to another barrier. And another exception is that a retainer plate 149 A′ is also shown at the right of the view. It will be readily appreciated by one skilled in the art that the shapes of the cavities, such as 117 A and 117 A′, are ones which allow access to coupling devices from above, that a drain hole (not shown) is desirable near the bottom of each adjacent pair of cavities, and that there should remains ample solid material at outer vertical edges of a mass of solid material to protect what is in the cavities formed between two adjacent barriers (as cavity 119 between barriers 113 A and 113 B shown in FIG. 1 ). One skilled in the art will also readily appreciate that the assembly shown is not the only configuration in which to store, ship, or handle a barrier, and that one might choose to store, ship, or handle the various components independently.
FIG. 3 shows a perspective view of three massive security barriers 113 A, 113 B, and 113 C coupled together side-against-side to form a security wall 103 ″ that rests on a ground surface 135 . Each barrier 113 A, 113 B, and 113 C is comprised of a mass of solid material 11 A, 11 B, and 11 C respectively. The side 129 A of barrier 113 A forms one end of the wall 103 ″, and the side 129 C′ forms the other end of the wall 103 ″. Between barriers 113 A and 113 B is an interface region 115 where the side 129 A′ of barrier 113 A is against the side 129 B of barrier 113 B. Between barriers 113 B and 113 C is an interface region 115 where the side 129 B′ of barrier 113 B is against the side 129 C of barrier 113 C. This massive security wall 103 ″ is much like, but longer by one barrier, than the security wall 103 shown in FIG. 1 . To change the wall 103 of FIG. 1 into the wall 103 ″ of FIG. 3 , the one additional barrier 113 C has been provided and positioned side-against-side to barrier 103 B, and an additional coupling device along with two additional retainer devices have been provided and installed.
FIG. 4 shows a perspective view of four massive security barriers 113 A, 113 B, 113 C, and 113 D coupled together side-against-side in a row to form a security wall 103 ′″ that has some of its vertical edges damaged but remains secured together. To change the wall 103 ″ of FIG. 3 into the wall 103 ′″ of FIG. 4 , the one additional barrier 113 D has been provided and positioned side-against-side to barrier 103 C, and an additional coupling device along with two additional retainer devices have been provided and installed. The wall 103 ′″ is shown in a non-straight line to illustrate a shape that might be caused by a terrorist vehicle having collided with the front of the wall 103 ′″ and dragging it along the ground. It is to be noted that vertical edges have been broken by compression in the masses of solid material 111 A, 111 B, and 111 C near the front of the wall resulting from collision-caused forces that were sufficient to cause at least some rotation between adjacent barriers 113 A and 113 B, between adjacent barriers 113 B and 113 C, and between adjacent barriers 113 C and 113 D. Such a pattern of rotation directions might result from a vehicle having crashed into the front of barrier 113 B.
In regard to FIG. 4 , one skilled in the art will appreciate that end portions of the tie-bars at the left end of the barrier 113 A, and end portions of the tie-bars at the right end of the barrier 113 D, of the security wall 103 ′″ in this view, can be retained from entering tunnels within the barriers 113 A and 113 D by using devices designed to anchor one or more ends of tie-bars to a barrier.
FIG. 5 shows barrier element 113 A in a view that is enlarged even further, shown with a middle portion of the barrier 113 A removed in order to fit into the view both sides 129 A and 129 A′ of the barrier 113 A. In this view, coupling pins and retainers are not present as they are in FIG. 2 , thus revealing in FIG. 5 that the mass of solid material 111 A includes a first tunnel 125 A and a second tunnel 127 A. Tunnels 125 A and 127 A are located in this embodiment with one over the other, the tunnel 125 A being above the tunnel 127 A. With one tunnel over another, a single coupling pin can be used to connect both tie-bars of one barrier to a similar pair of tie-bars in an adjacent barrier, as the coupling pin with head 173 couples barrier 113 A to 113 B shown in FIG. 1 .
In regard to FIG. 5 , the cross-sectional shapes of the tunnels 125 A and 127 A are shown in this implementation to be rectangular and bigger but not much bigger than the rectangular cross-sectional shapes of the tie-bars having ends 121 A and 123 A visible at the left-hand side of the view. One skilled in the art will readily appreciate that the cross-sectional shapes and sizes of the tunnels and tie-bars need not be constant over their lengths, but that typically they would be, and that the cross-sectional shape of a tunnel is not limited to rectangular, but could instead be square, circular, elliptical, triangular, polygonal, or even irregular.
In regard to FIG. 5 , the cross-sectional shape of a tie-bar, such as that with ends 121 A and 121 A′, is typically rectangular but can be of other shapes as is discussed below in regard to FIG. 16 , and a tie-bar is typically made of high-strength steel.
In regard to FIG. 5 , one skilled in the art will also readily appreciate that a barrier, such as 113 A, could be made with only a single tunnel 125 A and a single tie-bar as having tie-bar ends 121 A and 121 A′, or could be made with more than a single tie-bar in any one tunnel 125 A.
In regard to FIG. 5 , a mass of solid material, such as 111 A, which is also called a block, is typically shaped as a rectangular block but could have alternative shapes such as having beveled edges, and any of its surfaces could be other than flat. A mass of solid material, such as 111 A, is typically made of high-strength concrete and would typically include an inner structure of strengthening rebar as known in the prior art. And a mass of solid material, such as 111 A, can also typically include additional features such as a) hooks or loops in the top to aid manufacturers, distributors, and installers in lifting and positioning the mass of solid material, b) recesses in the bottom surface for use by fork-lifting equipment and for use in permitting the passage of water drainage, c) features to support ancillary objects such as surveillance cameras and lighting fixtures, and d) chases for routing communications and power cables or other utilities.
In regard to FIG. 5 , one skilled in the art will readily appreciate that a tunnel can be made into a mass of solid material (concrete for example) most conveniently by casting the material using a casting form that can accept and position a tube, whereby the tube defines the tunnel and can remain with the finished block when the block is removed from the form, the tube thus becoming a permanent part of the cast block. Alternatively, the tube can be coated at least on the outside with a release agent so that the tube can eventually be removed from the block. Also, alternatively, a tunnel can be defined by casting into the block a roll of bubble-wrapping material that can later be removed, or a tie-bar can be wrapped with bubble-wrapping material and then cast into place after which the bubble-wrapping material can be broken down with hot gas, a hot poker, or other tools.
FIG. 6 is similar to FIG. 5 and shows the barrier 113 A with the presence of retainers 149 A and 149 A′ but without the presence of coupling hardware. It can be readily appreciated that retainers 149 A and 149 A′ block entrances to the tunnels which they hide in this view. One of the purposes of using retainers such as these (they are sometimes optional) is that they can help to prevent the ends of tie-bars from being pulled into the entrances of the tunnels under applied applied tension to the tie-bars and given coupling devices that might otherwise deform sufficiently to be pulled into the tunnels along with ends of the tie-bars. When there are two tie-bars positioned along side of one another as illustrated in this embodiment, it is convenient to share one retainer at each of the barrier with both tie-bars, although this too is optional.
FIG. 7 shows a first example of a retainer 149 (means for retaining) which can be used to prevent one or two coupling devices near the ends of two tie-bars in a common barrier from entering either of two tunnels in the barrier. In the upper portion of the retainer 149 is a slotted hole 155 for location partly around an upper tie-bar, and a slotted hole 155 ′ for location partly around a lower tie-bar. An advantage of using a retainer with slotted holes instead of holes without slots is that such a retainer can be put into place about two tie-bars, before the coupling device is put into place. This can be done by lowering the retainer into a cavity alongside the tie-bars, such as cavity 119 shown in FIG. 1 if the cavity 119 is deep enough horizontally into the sides of the blocks, and then rotating the retainer in such a manner that the tie-bar ends move into the slots of the slotted holes.
FIG. 8 shows a second example of a retainer 149 ″ (means for retaining) which can be used to prevent one or two coupling devices near the ends of two tie-bars in a common barrier from entering either of two tunnels in the barrier. In this embodiment, however, there are no slots but only holes 157 and 157 ′. In this case, the installation of retainers can be accomplished for example by either a) positioning a first barrier block against a second barrier block and locating any desired retainers 149 ″ before slipping the last tie-bars for those two blocks into place, or b) slipping the retainer 149 ″ over two tie-bars already positioned within a barrier block and then positioning that block next to what becomes its adjacent neighbor to form an adjacent pair of blocks. And of course retainers of the type as 149 in FIG. 7 can also be installed in these ways.
In regard to FIGS. 7 and 8 , the shapes of retainers 149 and 149 ″ can be other than the rectangular shapes illustrated, the optimum shape being dependent upon the size and shape of any tunnel entrances they are designed to block, and depending upon the size(s) of the cavities within which they are situated in the sides of the barrier blocks.
FIG. 9 is a sectional view from FIG. 1 showing the coupling pin 171 (means for coupling) with its head 173 used to couple the two barriers 113 A and 113 B together sides-against-side with the tie-bars 161 A and 163 A of one barrier positioned end-to-end respectively with the tie-bars 161 B and 163 B of the other barrier. Also shown are the two retainers 149 A′ and 149 B (both are means for retaining) located to either side of the coupling pin 171 . In this cross-sectional view, note that the cross-section from FIG. 1 is taken from a position nearer the front surface 145 A (seen in FIG. 2 ) than the back surface 147 A (seen in FIG. 2 ). The position of the cross-section is such as not to cut into the coupling pin 171 or head 173 or either tie-bar 161 A or 163 A, but does cut into the retainers 149 A′ and 149 B and the masses of solid material 111 A and 111 B and their tunnels 125 A, 127 A, 125 B and 127 B. In this embodiment, the coupling pin 171 is shown with a threaded end 175 and fastened into place with washers 179 and a nut 177 . One skilled in the art will readily appreciate that the relative vertical positioning of the upper tie-bars 161 A and 161 B relative to one another, and the relative vertical positioning of the lower tie-bars 163 A and 163 B relative to one another, can be in any of a variety of arrangements and not just that shown with the tie-bars 161 B and 163 B positioned above the tie-bars 161 A and 163 A. For example, two tie-bars of one barrier can be located between two tie-bars of an adjacent barrier.
In regard to FIG. 9 , for illustrative purposes only, a small gap is shown between a side of the barrier 113 A and a mutually facing side of barrier 113 B, in the interface region 115 ; but this gap in practice should be kept as small as is practical and smaller than approximately the diameter of the illustrated coupling pin 171 . Preferably the two barriers 113 A and 113 B would be touching one another at their mutually facing sides. The purpose of keeping the gap at the interface region 115 as small as practical is to force portions of the solid material to have to be broken away from front and/or rear surfaces (such as front and rear surfaces 145 A and 147 A of barrier 113 A shown in FIG. 2 ) that include at least a portion of one of the vertical edges of one of the barriers (such as the vertical edges shown on barrier 113 A in FIG. 2 as edges 151 A, 153 A, 151 A′, or 153 A′) before significant mutual rotation can occur between adjacent barriers (such as between barriers 113 A and 113 B).
In regard to FIG. 9 , one skilled in the art will readily recognize that the coupling pin 171 that is shown coupling both upper tie-bars 161 A and 161 B together, as well as coupling both lower tie-bars 163 A and 163 b together, could be replaced with a coupling arrangement involving a pin (or one or more bolts) coupling the upper tie-bars that are separate from a pin (or one or more bolts) coupling the lower tie-bars. Another embodiment could use one coupling pin to both couple the upper tie-bars and to couple the lower tie-bars, but wherein either no threads or nut are used at the lower end of the coupling pin, or wherein threads and a nut are used just below the upper tie-bars either instead of or in addition to the threads and nut at the bottom end of the coupling pin.
FIG. 10 is similar to FIG. 9 , but wherein the two retainer devices 149 A′ and 149 B are not being used.
FIG. 11 is similar to FIG. 9 , but wherein the retainers 149 A 1 ′ and 149 B 1 are of modified form compared to the retainers 149 A′ and 149 B shown in FIG. 9 . These retainers 149 A 1 ′ and 149 B 1 have the added features 191 A′ and 191 B respectively that fill at least some of the otherwise empty space between the coupling pin 171 and what would otherwise be the locations of the previously shown retainers 149 A′ and 149 B respectively. In this manner, the coupling pin 171 (or some other choice of a coupling device) is afforded added protection under stress against bending or shifting its location relative to the other components shown in this view.
FIG. 12 is a perspective view showing a tie-bar 161 A with an oval-shaped hole 131 A near the tie-bar end 121 A, and an oval-shaped hole 131 A′ near the other tie-bar end 121 A′. In this view, the tie-bar 161 A is shown with its larger surfaces in a generally horizontal plane, as oriented in the embodiment of FIG. 1 . However, tie-bars such as 161 A can also be oriented with their larger surfaces in a generally vertical plane.
FIG. 13 is a close-up view of the end 121 A of the tie-bar 161 A shown in FIGS. 1 - 2 , 5 - 6 , 9 - 11 , and 12 . One of the disadvantages of having a hole 131 A near the end 121 A of this tie-bar 161 A is that sufficiently strong tension forces along the length of the tie-bar, when reacted against by forces in a coupling pin located in the hole 131 A, can result in failure of the tie-bar around the pin. The end 121 A can be made stronger by locating the hole farther away from the very end of the tie-bar and also by making the tie-bar wider and/or thicker (i.e. in directions lateral to the length of the tie-bar 161 A).
FIG. 14 is a perspective view of an end 121 A 1 of a modified tie-bar 161 A 1 that has it's thickness increased relative to that of the mid-portion of the tie-bar, requiring the hole 131 A 1 ′ to be deeper than illustrated in the previous views, and resulting in a tie-bar end 121 A 1 that is stronger than that of tie-bar end 121 A as shown in FIG. 13 . Since only the end portion 121 A 1 is made thicker, it is then possible, without weakening the rest of the tie-bar, to have a shelf-like step feature 195 A 1 . Depending upon how this step feature 195 A 1 is to be used in cooperation with alternative means for coupling, this step feature might have an abrupt step as illustrated or a gradual step as might be produced by a fillet of weld material.
FIG. 15 is a front view (or top view in an alternative embodiment) showing one example of means for coupling two modified tie-bars 161 A 1 and 161 B 1 together end-to-end. Whereas a modified (shorter) coupling pin is shown here with head 173 ″ and threads 175 ″ and used with washers 179 and a nut 177 , it will be readily appreciated by one skilled in the art that if the tie-bars 161 A 1 and 161 B 1 are to be oriented with their larger surfaces in a vertical plane, that multiple bolts could be used in place of a single coupling pin, and that this would provide equivalent means for coupling two tie-bars together. Since the tie-bars 161 A 1 and 161 B 1 have thicker ends 121 A 1 ′ and 121 B 1 , the coupling shown is a stronger one than if the tie-bars were not modified to have thicker ends and were the same thickness throughout their lengths as the thickness of the portions of the tie-bars 161 A 1 and 161 B 1 seen in this view to the left of the step feature 195 A 1 ′ and to the right of step feature 195 B 1 respectively.
FIG. 16 shows a perspective view of two enclosure parts 211 and 215 of an opened enclosure assembly that can be used, when closed and fastened to one another, to couple two modified tie-bars 161 A 2 and 161 B 2 at least approximately butt-end-to-butt-end without requiring any holes that would otherwise weaken the tie-bars 161 A 2 and 161 B 2 . The tie-bar ends 121 A 2 ′ and 121 B 2 are modified to have thicker ends than the middle portion of the tie-bars 161 A 2 and 161 B 2 respectively, and have to have step features 195 A 2 ′ and 195 B 2 respectively. When the two enclosure parts 211 and 215 are brought together to enclose the ends 121 A 2 ′ and 121 B 2 of the tie-bars 161 A 2 and 161 B 2 , their inner shapes are made to conform generally to the shapes of the tie-bar ends 121 A 2 ′ and 121 B 2 , thus using the step features 195 A 2 ′ and 195 B 2 to effectively lock the two tie-bars 161 A 2 and 161 B 2 together butt-end-to-butt-end, and thus coupling them together securely. The thicker portions created by the step features 195 A 2 ′ and 195 B 2 of the ends 121 A 2 ′ and 121 B 2 extend into a cavity or recess 213 in the enclosure part 211 . Multiple holes 217 in both enclosure parts 211 and 215 are used with bolts to secure the two parts 211 and 215 together. One skilled in the art can appreciate that other embodiments can be configured in the same spirit as that illustrated here. For example, the tie-bars could be made even thicker with a step feature (such as 195 A 2 ′ and 195 B 2 ) on both large faces of the ends of each tie-bar, and that the enclosure needed to attach them butt-end-to-butt-end could be made of two enclosure parts both having a respective recess such as part 211 shown. Another modification that can be made is to oversize the recess 213 to allow some play of the tie-bar ends 121 A 2 ′ and 121 B 2 to rotate somewhat in a plane parallel to the larger faces of the tie-bars. And another modification can be to have step features on not one or two sides of an end portion of a tie-bar, but on all four sides of a tie-bar having a square or rectangular cross-section end and to enclose two such tie-bars into a coupling enclosure that has recesses to accommodate each of the step features.
FIG. 17 shows a perspective view of the parts shown in FIG. 16 but wherein the two enclosure parts 211 and 215 are shown here as closed and fastened about the ends 121 A 2 ′ and 121 B 2 of two tie-bars 161 A 2 and 161 B 2 and thus serving as means for coupling the two tie-bars 161 A 2 and 161 B 2 together.
FIG. 18 shows an enlarged view of the barrier 113 A as seen on the left in FIG. 1 , except the mass of solid material is shown here to be comprised of two individual segments 111 A 1 and 111 A 2 that key into one another. The two segments are shown as separate from one-another but touching one another along the dividing line 303 A between segments, and along vertical edges 301 A of the segments. The dividing line 303 A generally has this shape throughout the heights of the segments, i.e. from top to bottom. Whether the mass of solid material 111 A consists of two segments 111 A 1 and 111 A 2 (as seen here in FIG. 18 ), or consists of only one single mass of solid material (as shown in FIG. 1 ), is optional, but in either case it is comprised of tunnels that extend all the way from the cavity 117 A on the left to the cavity 117 A′ on the right. One skilled in the art will readily appreciate that the dividing line 303 A is only one configuration of many that could be used to shape the interfacing ends of the two segments 111 A 1 and 111 A 2 or “sub-blocks”, and that the shape of the dividing line 303 A shown here demonstrates a stepped-back-and-forth shape that can provide the interface with strength to resist shearing laterally and horizontally between the two sub-blocks. The shape of the dividing line 303 A shown here can eliminate or at least reduce horizontal shear stress laterally. The tie-bar ends 121 A and 123 A of the tie-bars 161 A and 163 A are shown here on the left, but the tunnels 125 A and 127 A are not visible in this figure.
FIG. 19 shows one segment 111 A 2 of the two segments 111 A 1 and 111 A 2 of the barrier 113 A of FIG. 18 , designed with tunnels 125 A 2 and 127 A 2 for tie-bars. Channels that are the extensions of the tunnels 125 A 2 and 127 A 2 are visible in this view and given the call-out designations of the tunnels since when interfaced with the other segment 111 A 1 , these channels complete mid-portions of the tunnels 125 A 2 and 127 A 2 by aligning with similar channels in the other segment 111 A 1 . It can be readily appreciated by one skilled in the art that the dividing line 303 A shown in FIG. 18 is one that permits the two segments 111 A 1 and 111 A 2 to be symmetrical and therefore identical, and that this reduces the need for manufacturers to make two different types of segments.
FIG. 20 shows a modified version 111 A 2 ′ of the segment 111 A 2 shown in FIG. 19 , designed without tunnels and having tie-bars 161 A and 163 A cast in place within the segment 111 A 2 ′. Such a modified segment 111 A 2 ′ can be interfaced with a segment such as 111 A 2 shown in FIG. 19 . One skilled in the art can readily appreciated that such a combination of segments 111 A 2 and 111 A 2 ′ can permit a complete barrier in which a means for retaining coupling devices are not required as the tie-bars are cast within the segment 111 A 2 ′.
One skilled in the art will readily appreciate that the installation and assembly of a security wall such as illustrated in FIG. 1 , if involving larger numbers of barriers than merely two, can involve placing into location and coupling one additional barrier at a time, either always at the same one end of a row or at either end of a row, or placing into location a group of adjacent barriers and proceeding to couple selected adjacent pairs sequentially down the row or in any order of sequence.
One skilled in the art will appreciate that other structure for means for coupling and arrangements of one or more tie-bars in massive barriers can be used. One example would be the rotation of the tie-bar(s) 90 degrees about their longitudinal axes and coupling them with one or more pins or bolts and nuts, in which case any mutual rotation of adjacent barriers would incur bending of the tie-bars near the cavities as portions of the mass of solid material that interfere with the rotation break away. Other examples would include, but not be limited to, the use of clamping devices, couplings as used to couple railway cars together, interlocking mechanisms, mechanisms such as used to hook a trailer to a tractor, and equivalent linking devices used to attach two bodies to one another and allow some relative mutual rotation between the two bodies. Such alternative embodiments for coupling devices are considered herein to be other equivalents of means for coupling barrier blocks together.
One skilled in the art will appreciate that other means for retaining can be used than those described above. Since the purpose of a retainer in this invention is to constrain the end(s) of one or more tie-bars from being pulled into a tunnel, and possibly also to constrain the end(s) from translating laterally relative to a nearby tunnel entrance, it can be appreciated by one skilled in the art that equivalent means for retaining can be any retainer device that can serve as an obstruction to an end of one or more tie-bars (or to a coupling means to which the tie-bar end(s) is/are attached) in either or both the lateral and longitudinal directions. If it is to provide restraint in the lateral direction, such obstruction would at least resist lateral movement of a tie-bar end from moving outsides of the cavity in a barrier within which it was installed. If it is to provide restraint in the longitudinal direction, such an obstruction would at least resist longitudinal movement of a tie-bar end from moving into a tunnel. One skilled in the art will readily appreciate that if the structure of means for coupling is larger laterally than the entrance to a tunnel, or larger enough to restrict lateral motion within a cavity of a barrier into which it is installed, then it can serve in either case respectively as means for retaining in the longitudinal or lateral directions. And one skilled in the art will readily appreciate that structures of means for coupling that simultaneously couple multiple tie-bars of one barrier to those of an adjacent barrier intrinsically serve as means for retaining. It is therefore intended that all such equivalents of means for coupling and means for retaining should be considered equivalents to those illustrated in the drawings and previously disclosed in this specification.
One skilled in the art will appreciate that shapes for the mass of solid material comprising a barrier can be other than that shown in the illustrated embodiments within this specification. For example, the sides of the barrier blocks can be made in a shape that permits features in the side of one barrier block to key into complementary features in the oppositely facing side of an adjacent barrier block, this to strengthen shear resistance to resist lateral displacements between adjacent barriers and thus potentially reduce the shear forces experienced by coupling devices when a security wall experiences a terrorist event intended to breach the wall. In another example, the opposite sides of a barrier block don't necessarily have to be parallel, but could be at an angle to one another as to accommodate a change of longitudinal direction somewhere along a row of barriers.
Under “Objects and Advantages of the Invention” presented above, it was stated that the invention comprises barrier blocks that have bottoms that are resistant to sliding over the ground (or over another supporting surface), that the bottom of a block should have a high coefficient of friction with the supporting surface. One skilled in the art will readily appreciate that the energy required to move or otherwise slide a block over a supporting surface can be effectively increased with some types of supporting surfaces by incorporating a tread-like surface or even cleats or spikes on the bottom of barrier blocks. Where it is known that there are no underground utilities to be damaged, ground anchors (e.g. piers) can be used to anchor barriers firmly to the ground at some locations along a wall, but still allowing other locations to slide. Barrier blocks or tie-bars can be tethered loosely to ground anchors by means of cables having a fixed length of slack and thereby designed to bring a moving wall to an earlier halt than otherwise after a given distance of sliding, or even tethered taught with a frictional braking means to feed out cable while absorbing kinetic energy from the wall as it is dragged from its installed position.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement configured to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the invention. It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combinations of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description. The scope of various embodiments of the invention includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled. | Barrier elements provide security from terrorist threats by ability to withstand both vehicle collisions and explosive blasts. Each barrier element is prefabricated to include a massive block of durable material, preferably of high strength concrete, with at least one tunnel extending at least partially between respective cavities in two opposite sides of the block. Each barrier element also includes at least one beam that is preferably made of steel and extends through one such tunnel. Multiple blocks are positionable slidably on top of the ground side-against-side with their beams coupled longitudinally to one another at least approximately end-to-end. Retainer means can be used to block coupling means from entry into the tunnels. Forces from a vehicle collision or an explosive blast can cause barrier elements to rotate relative to one-another when the couplings between beams hinge or bend as the durable material that interferes with the rotation breaks away. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
PROVISIONAL PATENT APPLICATION NO. 60849339
FILED: Oct. 4, 2006.
FEDERALLY SPONSORED RESEARCH
Not Applicable.
SEQUENCE LISTING PROGRAM
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates in general to an inverted-sprinkler system for inverting and elevating water sprinklers. Inversion of the sprinklers, as shown and described herein, means turning the sprinkler upside down and securing it from an elevated position above the ground such that fluid is directed from above to the desired coverage area below, much like natural rainwater. The invention is directed, in particular, to a base and support structure that elevates and inverts an oscillating wave-type sprinkler, a rotary-type sprinkler, a pulsating type sprinkler, an impulse-type sprinkler, and a plurality of other sprinklers for the efficient and uniform distribution, from above, of any fluid that is to be dispensed over a particular surface or coverage area.
2. Prior Art
The effective sprinkler coverage area of residential and commercial irrigation systems is often reduced by growing crops, vines, shrubbery, trees and other natural and man-made obstacles which interfere with the stream of water ejected by the sprinkler. There are any number of commercially available sprinklers utilized in such irrigation systems. Oscillating sprinklers, for example, are commonly used to cover square or rectangular coverage areas. Typical oscillating wave-type sprinklers are described in U.S. Pat. No. 4,860,954 issued to Allemann (1989); U.S. Pat. No. 4,252,246 B2 issued to Heren, et al. (1981); U.S. Pat. No. 4,245,786 issued to Abrahamsen (1981); and U.S. Pat. No. D303,283 issued to Best, et al. (1989). Rotary sprinklers are commonly used to cover circular or elliptical coverage areas. Typical rotary sprinklers are described in U.S. Pat. No. 5,307,993 issued to Simmonetti (1994) and U.S. Pat. No. D378,399 issued to Simmonetti (1997). Pulsating sprinklers are commonly used to cover circular, angular, or elliptical coverage areas. Typical pulsating sprinklers are described in U.S. Pat. No. 4,978,070 issued to Chow (1990). Impulse sprinklers are also commonly used to cover circular, angular, or elliptical coverage areas. Typical impulse sprinklers are described in U.S. Pat. No. 4,907,742 issued to Whitehead and Ferguson (1990). Sprinklers are typically positioned on the ground in the center of the sprinkler coverage area. In the case of the oscillating wave-type sprinkler, locking devices are provided to restrict the coverage area by restraining the lateral movement of the sprinkler head, by having a pattern select feature (Heren and Breedlove, U.S. Pat. No. 7,252,246 B2 (2007)) or a sprinkler with perforated spray hose that is selectively flexed to produce a variable water spray pattern (Abrahamsen and Spector, U.S. Pat. No. 4,245,786 (1981)). In the case of pulsating and impulse sprinklers, deflectors are provided to minimize or maximize coverage areas by restraining the rotational limits of the sprinkler head.
A number of devices have been suggested to elevate the sprinkler above the level of the ground in order to allow the stream of water to pass without obstruction over vertical obstacles. Most such devices are sprinkler stands of some form which elevate the sprinkler above ground level to an appropriate height where fluid leaving the sprinkler is no longer blocked.
Inventors have created several types of sprinkler stands to maintain a sprinkler in an elevated position. Adequate for overcoming obstacles which block the delivery of water, these devices nonetheless have limited utility in achieving sprinkler coverage area patterns specific to the need of the residential or commercial gardener and others desiring to use sprinklers to deliver fluid to precise coverage areas.
U.S. Pat. No. 4,824,020 to Harward (1989), for instance, discloses a lightweight vertical support stand for a water sprinkler head. The invention has flexible elongated legs which are pivotally attached to a support hub. This invention is an improvement on earlier stands, such as U.S. Pat. No. 1,959,886 to Wadsworth (1934) and U.S. Pat. No. 2,694,600 to Richey (1954) which taught elevated tripod sprinkler stands with bases of varying stability, weight, and mobility. U.S. Pat. No. 4,884,749 issued to Ruprechter, (1989) teaches a swingable mount which tends to orient the sprinkler on nonlevel ground by the force of gravity. It has the advantage of optimizing sprinkler coverage area on nonlevel ground. Other than addressing the vertical limitations of watering nonlevel ground, however, it does little to overcome more typical vertical obstacles such as shrubs, vines, growing crops, and the like.
U.S. Pat. No. 6,322,027 issued to Hsu (2001) discloses yet another adjustable sprinkler stand, including a sprinkler mount which is supported by three adjustable support rod sets. A principal objective of the device is to elevate the sprinkler by means of the three adjustable support rods which can be set to various heights.
In all of these devices, the primary objective was to vertically elevate a water sprinkler head to reduce interference with the sprinkler coverage area caused by vertical obstacles.
United States Patent Application Publication No. US2007/0051829 A1 (Griffin, Mar. 8, 2007) discloses a stand for an oscillating wave-type sprinkler. The stand holds an oscillating wave-type sprinkler in an elevated and generally vertical orientation to provide desired sprinkler coverages. The device is limited to use with oscillating wave-type sprinklers and does not teach the complete inversion of the sprinkler to achieve the type of direct downward spray coverage areas taught by this invention.
Each of the foregoing inventions suffers from a number of common disadvantages.
a) The primary objective of the devices is limited to maintaining the sprinkler in an elevated position.
b) None of the devices allow for the full inversion of the sprinkler from an elevated position.
c) All of the devices direct the pressure of water leaving the sprinkler up from the surface in some fashion before gravity pulls the stream back toward the ground.
d) None of the devices teach the simultaneous elevation and complete inversion of the sprinkler head to achieve desired fluid coverage from above.
e) None of the devices teach the use of sprinkler stands to direct water leaving the sprinkler directly down to the ground.
f) Not all of the devices are able to achieve uniform and efficient watering because they spray water into the air, where it falls to the ground after the stream reaches its apogee, sometimes blowing beyond the desired coverage area, rather than spraying the water directly from above toward the ground.
g) None of the devices mimic natural rainfall by providing an elevated sprinkler which is inverted such that fluid is directly applied to the coverage area from above.
h) None of the devices have the variety of horizontal, vertical, and angular adjustments as does the present invention.
i) None of the devices allow the elevation and inversion of a plurality of sprinkler types (e.g. wave, rotary, oscillating, pulsating, impulse, etc.).
OBJECTS AND ADVANTAGES
Accordingly, the clear objects and advantages of the present invention are:
a) To provide an inverted-sprinkler system which simultaneously elevates and inverts the sprinkler to achieve desired fluid coverage areas.
b) To provide a vertical support member, adjustable in length, to elevate a horizontal support member, also adjustable in length, upon which a sprinkler base is attached for sprinkler inversion.
c) To provide for desired irrigation coverage areas by inverting a plurality of sprinkler types for direct fluid application from above.
d) To provide for portability and stability of the system by means of a plurality of support bases.
e) To provide for the adjustment of the vertical height and horizontal reach of the sprinkler base support by means of telescopic adjustment.
f) To provide for the adjustment of the angle between the vertical support member and horizontal support member by means of a slanted support member with telescopic adjustment.
g) To provide a sprinkler base support with fastening means for the inverted support of a plurality of sprinklers.
h) To provide for the further fine adjustments of the vertical and horizontal support members by means of rotational movement of each support member along its axis.
i) To provide for the further fine adjustment of the angle of the sprinkler support base to the horizontal support member by means of adjustment screws.
j) To couple the invention to a hose timer to facilitate automatic dispensing of fluid.
Further objects and advantages are to provide an inverted-sprinkler system which can be used easily and conveniently to irrigate residential and commercial lawns, gardens, row crops, greenhouses, nurseries, and the like; to allow for the quick and portable transport and movement of the vertical sprinkler system; to save watering time; to conserve water use through direct application; to easily remove, disassemble and store the system; to allow for the precise application of fluids to the desired sprinkler coverage area; to mimic natural rainfall by delivering water from an elevated source; to achieve uniform and rain-like watering of plants; and to function in outdoor and indoor settings.
SUMMARY
In accordance with the present invention an inverted-sprinkler system comprising an adjustable vertical support member secured to a sprinkler system base, said vertical support member able to rotate axially; an adjustable horizontal support member, also able to rotate axially; said vertical and horizontal support members pivoting about a pin to form a right angle; a slanted support member attached to the horizontal and vertical support members near the pivot pin to allow for the adjustment of the angle between said horizontal and vertical support members; a sprinkler support base attached to the distal end of said horizontal support member to secure and permit the inversion of a plurality of sprinklers, the angle of said sprinkler support base to the horizontal support member being adjustable; for the direct and elevated application of water and other fluids (e.g. fertilizer, herbicide) to the desired sprinkler coverage area.
DRAWINGS—FIGURES
FIG. 1 —Shows an isometric view of inverted-sprinkler system: base and support.
FIG. 2 —Shows an exploded isometric view of inverted-sprinkler system: base and support.
FIG. 3 shows a side view of the inverted-sprinkler system: base and support.
FIG. 4 shows a front view of the inverted-sprinkler system.
FIG. 5 shows a side view the adjustable vertical support member at the telescopic locking device.
FIG. 6 shows a side view the adjustable horizontal support member at the telescopic locking device.
FIG. 7 shows a side view of the slanted support member and pivot pin connecting the vertical support member and horizontal support member.
FIG. 8 shows the sprinkler system base in its preferred embodiment.
FIG. 9 shows a side view of the sprinkler support base in its preferred embodiment.
FIG. 10 shows a side view of the sprinkler support base J-clamp and clamp down nuts.
FIG. 11 shows a side view of the sprinkler support base and u-bolt attachment.
FIG. 12 shows a side view of an alternate embodiment of the invention utilizing tandem frames.
FIG. 13 shows an isometric view of an alternate embodiment of the invention with sprinkler attached directly to the adjustable horizontal support member.
FIG. 14 shows side views of three alternate embodiments of the invention, with the sprinkler mounted on an interior wall, an exterior wall, and a ceiling.
FIG. 15 shows an isometric view of the invention, with the sprinkler system mounted on wheels.
DETAILED DESCRIPTION
A preferred embodiment of the present invention is illustrated in FIG. 1 (isometric view) and FIG. 2 (exploded isometric view), FIG. 3 (side view), FIG. 4 (front view), FIG. 5 (side view of the adjustable vertical support member), FIG. 6 (side view of adjustable horizontal support member), FIG. 7 (side view of slanted support member), FIG. 8 (sprinkler system base), FIG. 9 (side view of sprinkler support base), FIG. 10 (side view of sprinkler support base J-clamp and clamp down nuts), and FIG. 11 (side view of sprinkler support base and U-bolt attachment). Alternate embodiments are shown in FIG. 12 (side view of inverted-sprinkler system utilizing tandem frames), FIG. 13 (isometric view of sprinkler attached directly to the adjustable horizontal support member), FIG. 14 (side views of the sprinkler mounted on an interior wall, an exterior wall, and a ceiling), and FIG. 15 (isometric view of the sprinkler system mounted on wheels).
The inverted-sprinkler system depicted is constructed of durable and lightweight material. In its preferred embodiment, the inverted-sprinkler system is made of hard plastic. However, it can consist of any other durable and lightweight material suited for fabrication into a weather-proof stand, including aluminum, lightweight metal alloys, fiberglass, or laminates. In its preferred embodiment, the inverted-sprinkler system is comprised of vertical and horizontal support members through which residential or commercial hose is internally contained. Alternatively, the hose may be externally supported by the vertical and horizontal support members.
As shown in the preferred embodiment, the proximal end of the vertical support member 1 ( FIG. 2 , 3 , 4 , 5 , 7 , 8 ) is coupled to a base connection member 4 ( FIG. 2 , 3 , 5 , 8 ). The base connection member 4 ( FIG. 2 , 3 , 5 , 8 ) is seated into a sprinkler system base 2 ( FIG. 2 , 3 , 8 ). In its preferred embodiment, the sprinkler system base is a cylindrical tripod having three offsetting cylindrical ground stakes to secure the water sprinkler system to the surface. A hose hub 3 ( FIG. 2 , 8 ) is situated beneath the center of the sprinkler system base 2 ( FIG. 2 , 3 , 8 ) for the connection of a garden or commercial hose to the bottom of the device. The hose hub 3 ( FIG. 2 , 8 ) is threaded into the base connector member 4 ( FIG. 2 , 3 , 5 , 8 ). In other embodiments, the sprinkler support base may be formed to take other stable geometric shapes (e. g. squares, circles) and may employ weights, instead of stakes, to support the system or wheels to make the system even more mobile.
An adjustable horizontal support member 5 A ( FIG. 2 , 3 , 6 , 7 , 9 ) and 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ) is affixed to the vertical support member 1 ( FIG. 2 , 3 , 4 , 5 , 7 , 8 ) as shown by means of a pivot pin and tongue and groove plates 16 ( FIG. 2 , 3 , 7 ). In its preferred embodiment, a length of hose 6 ( FIG. 2 , 3 , 7 , 9 , 13 ) is contained within portions of the vertical and horizontal support members as shown.
The adjustable horizontal support member 5 A ( FIG. 2 , 3 , 6 , 7 , 9 ) and 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ) also is affixed to the vertical support member 1 ( FIG. 2 , 3 , 4 , 5 , 7 , 8 ) by an adjustable slanted support member 7 A ( FIG. 2 , 3 , 7 ) and 7 B ( FIG. 2 , 3 , 7 ). The adjustable slanted support member 7 A ( FIG. 2 , 3 , 7 ) and 7 B ( FIG. 2 , 3 , 7 ) is adjustable in length to allow the adjustable horizontal support member to rotate about the pivot pin at plurality of angles. In other embodiments, the adjustable slanted support member 7 A ( FIG. 2 , 3 , 7 ) and 7 B ( FIG. 2 , 3 , 7 ) and pivot pin and tongue and groove plates 16 ( FIG. 2 , 3 , 7 ) may be replaced with a fixed and non-adjustable connector (e.g. 90° elbow). The tubing in the vertical support member 1 ( FIG. 2 , 3 , 4 , 5 , 7 , 8 ) and base connection member 4 ( FIG. 2 , 3 , 5 , 8 ); the adjustable horizontal support member 5 A ( FIG. 2 , 3 , 6 , 7 , 9 ) and 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ); and the adjustable slanted support member 7 A ( FIG. 2 , 3 , 7 ) and 7 B ( FIG. 2 , 3 , 7 ) is of two diameters to allow them to retract and extend telescopically. A telescopic locking device 8 ( FIG. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 13 ) is located where the smaller and larger diameters of tubing insert into one another. It may be hand fastened or loosened to allow for the telescopic expansion or retraction of the vertical support member, the adjustable horizontal support member, and/or the adjustable slanted support member, as needed. In addition, the vertical support member 1 ( FIG. 2 , 3 , 4 , 5 , 7 , 8 ) and the adjustable horizontal support member 5 B ( FIG. 2 , 3 , 6 , 7 , 9 , 13 ) may be rotated axially where the smaller and larger diameters of tubing connect at the telescopic locking device 8 ( FIG. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 13 ). The sleeves surrounding the vertical support member 1 ( FIG. 2 , 3 , 4 , 5 , 7 , 8 ) and the adjustable horizontal support member 5 A ( FIG. 2 , 3 , 6 , 7 , 9 ) at either end of the adjustable slanted support member 7 A ( FIG. 2 , 3 , 7 ) and 7 B ( FIG. 2 , 3 , 7 ) have a diameter sufficiently wide to allow this axial rotation.
Affixed to the distal end of the horizontal support member is a sprinkler support base 9 ( FIG. 2 , 3 , 4 , 9 , 11 , 12 ). In its preferred embodiment, the sprinkler support base is comprised of a rectangular plate 9 ( FIG. 2 , 3 , 4 , 9 , 11 , 12 ) used to secure an inverted sprinkler 10 ( FIG. 2 , 3 , 4 , 9 , 13 ). Sprinkler support base J-clamps 11 ( FIG. 2 , 3 , 4 , 9 , 10 ) are used with clamp down nuts 14 ( FIG. 2 , 4 , 10 ) to lock and unlock the sprinkler into its inverted position. The sprinkler support base 9 ( FIG. 2 , 3 , 4 , 9 , 11 , 12 ) is secured to the adjustable horizontal support member 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ) by two U-bolt attachments 12 ( FIG. 2 , 3 , 4 , 9 , 11 , 14 ). Two horizontal elevation knobs 13 ( FIG. 2 , 9 , 11 ) are used to make fine adjustments to the angle between the sprinkler support base 9 ( FIG. 2 , 3 , 4 , 9 , 11 , 12 ) and the horizontal support member 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ).
In an alternate embodiment, the sprinkler support base 9 ( FIG. 2 , 3 , 4 , 9 , 11 , 12 ) is further affixed, as shown on FIG. 12 , to tandem frames, each having an adjustable horizontal support member, a base support member, a vertical support member, an adjustable slanted support member, sprinkler support base, each of the said support members further having the adjustable features previously described. In another embodiment, an inverted sprinkler 10 ( FIG. 2 , 3 , 4 , 9 , 13 ) is attached, as shown on FIG. 13 , directly to the horizontal support member 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ). In yet another embodiment, U-bolt attachments 12 ( FIG. 14 ) are used to secure the sprinkler support members to an external structure such as a wall or a ceiling. Finally, in another embodiment, the sprinkler system is stably mounted on wheels 17 ( FIG. 15 ) for mobility.
Advantages
From the description above, a number of advantages of the inverted-sprinkler system become evident:
a) The system is. compact and portable.
b) The system allows both commercial and amateur horticulturalists to quickly set up an elevated irrigation system to achieve direct watering or application of other fluids from above the coverage area.
c) The system allows a user to adjust the elevation and angular orientation of the system to increase or decrease coverage area and watering intensity.
d) The system allows a user to adjust the angle of the horizontal support member to assure uniform application rates in circumstances such as irrigating non-level surfaces.
e) The system allows for the complete inversion of a plurality of sprinklers such that irrigation is uniform and natural (like rain).
f) The base allows for easy movement and relocation of the system.
g) The angle between the sprinkler support base and the horizontal support member may be finely adjusted to create exactly and uniform sprinkler coverage areas.
h) The vertical and horizontal support members may be lengthened or shortened as needed. This feature allows the system to be located just above the desired coverage area thereby reducing wind drift of fluid during sprinkling.
i) The vertical and horizontal support members may be rotated axially as needed.
j) The system allows a user to make further adjustments using the locking and deflecting mechanisms indigenous to the type of sprinkler being inverted (e. g. wave-type, impulse-type, and pulsating-type).
h) Fluid pressure may be varied to adjust the flow rate and coverage area.
Although the description above contains many specifications, these should not be construed as limiting the scope of the invention, but merely as providing illustrations of preferred embodiments of this invention. For example, the system can have many dimensions; the support members and base members can be made of aluminum, lightweight metal, alloys, fiberglass or laminates; the interior hose can be eliminated and a garden house secured to the vertical and horizontal members with exterior fasteners; the support members may take shapes other than cylindrical; the sprinkler support base may take shapes other than rectangular; all types of sprinklers may be inverted; the telescopic member locking devices may be replaced with other types of locking devices (e. g. slides and fasteners); the telescopic member locking devices may be fixed to certain heights and lengths; the sprinkler support base may be affixed in tandem to counterpart frames, each having an adjustable horizontal support member, a base support member, an adjustable slanted support member, and a sprinkler support base to give the system additional support, a reduced propensity to tip, and wider areas of coverage; the tandem counterpart frame embodiment may be utilized to affix more than one sprinkler support base; the sprinkler support base may be eliminated and a plurality of sprinklers (e.g. wave, rotary, oscillating, impulse, etc.) may be inverted and secured from the distal end of the adjustable horizontal support member by other fastening means (e. g. a coupler to thread said plurality of sprinkler directly to said distal end) as shown in FIG. 13 ; an inverted sprinkler and horizontal support member 5 B ( FIG. 2 , 3 , 6 , 9 , 13 ) can be-manufactured as one unit that can slide into an internal hose and telescopic locking device 8 ( FIG. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 13 ); the pivot pin and tongue and grove plates and adjustable slanted support member may be replaced by other non-adjustable fittings (e.g. fixed 90° elbows); the sprinkler support base only, may be secured to the interior of greenhouses or other external structures from above using a plurality of fastening means (e. g. wire, clamps, tie-rods); the invention, with sprinkler support base detached, may be secured to the interior of greenhouses or other external structures using wall mounts; J-clamps and U-bolt attachments may be replaced with other fasteners (e. g. hose clamps, U-clamps, and tie-rods); a hose timer may be used to automatically control the application of fluids. Flow pattern can be further adjusted by blocking (or increasing) the number of holes through which water is discharged by the sprinkler, using a sprinkler that uses a pattern select feature (Heren and Breedlove, U.S. Pat. No. 7,252,246 B2 (2007)) or a sprinkler with perforated spray hose that is selectively flexed to produce a variable water spray pattern (Abrahamsen and Spector, U.S. Pat. No. 4,245,786 (1981)). Furthermore, if a larger coverage area is required, the embodiment shown in FIG. 12 can be duplicated (repeated) as many times to cover the desired coverage area. Thus the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given. | An adjustable inverted-sprinkler system for irrigation. The system includes a sprinkler support base fashioned to accept and retain plurality of sprinklers in a generally inverted orientation. The sprinkler support base is supported by a frame having adjustable vertical, horizontal and slanted support members to allow precise direct, efficient and uniform watering from above. The frame is coupled to a base which allows it to be securely grounded during use and quickly moved as needed by the user. | 1 |
This is a divisional application of U.S. Application Ser. No. 07/565,306 filed Aug. 9, 1990.
BACKGROUND OF THE INVENTION
Excessive excitation by neurotransmitters can cause the degeneration and death of neurons. It is believed that this degeneration is in part mediated by the excitotoxic actions of glutamate and aspartate at the N-methyl-D-aspartate (NMDA) receptor. This excitotoxic action is responsible for the loss of neurons in cerebrovascular disorders such as: cerebral ischemia or cerebral infraction resulting from a range of conditions such as thromboembolic or hemorrhagic stroke, cerebral vasospasm, hypoglycemia, cardiac arrest, status epilepticus, perinatal asphyxia, cerebral trauma and anoxia (such as from drowning and pulmonary surgery).
There are no specific therapies for these neurodegenerative diseases, however, compounds which act specifically as antagonists of the NMDA receptor complex, either competitively or noncompetitively, offer a novel therapeutic approach to these disorders: R. Schwarcz and B. Meldrum, The Lancet 140 (1985); B. Meldrum in "Neurotoxins and Their Pharmacological Implications" edited by P. Jenner, Raven Press, New York (1987); D. W. Choi, Neuron 1:623 (1988). Confirmation of the protective effects of noncompetitve NMDA antagonists in various pharmacological models of neurodegenerative disorders have appeared in the literature: J. W. McDonald, F. S. Silverstein, and M. V. Johnston, Eur. J. Pharmocol. 140:359 (1987); R. Gill, A. C. Foster, and G. N. Woodruff, J. Neurosci. 7:3343 (1987); S. M. Rothman, J. H. Thurston, R. E. Hauhart, G. D. Clark, and J. S. Soloman, Neurosci. 21:673 (1987); M. P. Goldbert, P-C. Pham, and D. W. Choi, Neurosci. Lett. 80:11 (1987); L. F. Copeland, P. A. Boxer, and F. W. Marcoux, Soc. Neurosci. Abstr. 14 (part 1):420 (1988); J. A. Kemp, A. C. Foster, R. Gill, and G. N. Woodruff, TIPS 8:414 (1987); R. Gill, A. C. Foster, and G. N. Woodruff, J. Neurosci. 25:847 (1988); C. K. Park, D. G. Nehls, D. I. Graham, G. M. Teasdale, and J. M. McCulloch, Ann. Neurol. 24:543 (1988); G. K. Steinburg, C. P. George, R. DeLaPlaz, D. K. Shibata, and T. Gross, Stroke 19:1112 (1988); J. F. Church, S. Zeman, and D. Lodge, Anesthesiology 69:702 (1988).
The compounds of the present invention are useful in the treatment of neurodegenerative disorders including cerebrovascular disorders. Such disorders include but are not limited to cerebral ischemia or cerebral infarction resulting from a range of conditions such as thromboembolic or hemorrhagic stroke, cerebral vasospasm, hypoglycemia, cardiac arrest, status epilepticus, perinatal asphyxia, cerebral trauma and anoxia such as from drowning and/or pulmonary surgery. Other treatments are for schizophrenia, epilepsy, spasticity, neurodegenerative disorders such as Alzheimer's disease or Huntington's disease, Olivo-pontocerebellar atrophy, spinal cord injury, and poisoning by exogenous NMDA poisons (e.g., some forms of lathyrism). Further uses are as analgesics and anesthetics, particularly for use in surgical procedures where a finite risk of cerebrovascular damage exists.
SUMMARY OF THE INVENTION
The present invention concerns compounds of the formula I ##STR1## or a pharmaceutically acceptable acid addition salt thereof wherein R 1 , R 2 , R 3 , m, and n are as described herein below.
The present invention also includes a pharmaceutical composition comprising a therapeutically effective amount of a compound of formula I together with a pharmaceutically acceptable carrier.
The present invention also includes a method for treating cerebrovascular disorders which comprises administering to a patient in need thereof the above pharmaceutical composition in unit dosage form.
The present invention also includes a method of treating disorders responsive to the blockade of glutamic and aspartic acid receptors in a patient comprising administering a therapeutically effective amount of the above composition.
The invention also includes a method for treating cerebral ischemia, cerebral infarction, cerebral vasospasm, hypoglycemia, cardiac arrest, status epilepticus, cerebral trauma, schizophrenia, epilepsy, neurodegenerative disorders, Alzheimer's disease, or Huntington's disease comprising administering to a patient in need thereof a therapeutically effective amount of the above composition.
The invention also includes a method for treating stroke in patients in need thereof which comprises administering to a patient in need thereof a therapeutically effective amount of the above composition.
The invention also includes using as an anesthetic the above composition in surgical operations where a risk of cerebrovascular damage exists.
The invention further includes processes for the preparation of compounds of formula I.
The invention still further includes novel intermediates useful in the processes.
DETAILED DESCRIPTION
The present invention concerns compounds of the formula ##STR2## or a pharmaceutically acceptable acid addition salt thereof wherein: R 1 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, arylloweralkyl, cyclopropylloweralkyl, or a pharmaceutically acceptable labile group;
R 2 and R 3 are each independently hydrogen, lower alkyl, hydroxy, lower alkoxy, halogen, amino, monoloweralkylamino, diloweralkylamino;
m is an integer of from 0 to 2; and
n is an integer of from 2 to 4.
Preferred compounds of the instant invention are those of formula I wherein:
R 1 is hydrogen, lower alkyl, lower alkenyl, cyclopropylmethyl or arylloweralkyl;
R 2 and R 3 are independently hydrogen, lower alkyl, hydroxy, or lower alkoxy;
m is an integer of 0 or 1;
n is 2 or 3; and
indicates the ring is cis relative to its attachment at to the molecule.
More preferred compounds of the instant invention are those of formula I wherein:
R 1 is hydrogen, lower alkyl, cyclopropylmethyl, or arylloweralkyl;
R 2 and R 3 are independently hydrogen, hydroxy, or lower alkoxy;
m is an integer 0 or 1; and
n is an integer 2 or 3.
Still more preferred are compounds of formula I wherein:
R 1 is hydrogen, methyl, ethyl, propyl, allyl, cyclopropylmethyl, or benzyl;
R 2 and R 3 are each independently hydrogen, methoxy, or hydroxy;
m is the integer 0 or 1; and
n is the integer 2 or 3.
Other more preferred compounds of the instant invention include:
(+), (-), or (±)-2,3-Dihydro-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole,
(+), (-), or (±)-2,3-Dihydro-7-methoxy-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole,
(+), (-), or (±)-2,3-Dihydro-1-methyl-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole,
(+), (-), or (±)-2,3-Dihydro-7-methoxy-1-methyl-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole,
(+), (-) or (±)-2,3-Dihydro-7-methoxy-1-ethyl-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole,
(+), (-), or (±)-2,3,4,5-tetrahydro-1-(2-propenyl)-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-3a,9b-butano-1H-benz[g]indol-8-ol,
(+), (-), or (±)-2,3,4,5-Tetrahydro-1-methyl-3a,9b-butano-1H-benz[g]indol-8-ol,
(+), (-), or (±)-2,3-Dihydro-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrol-7-ol,
(+), (-), or (±)-2,3-Dihydro-1-methyl-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrol-7-ol,
(+) (-), or (±)-1,2,3,4,5,6-Hexahydro-4a,10b-butanobenz[h]quinoline,
(+), (-), or (±)-1,2,3,4,5,6-Hexahydro-9-methoxy-4a,10b-butanobenz[h]quinoline,
(+), (-), or (±)-1,2,3,4,-Tetrahydro-4a,9b-butano-5H-indeno[1,2-b]pyridine,
(+), (-) , or (±)-1,2,3,4,-Tetrahydro-8-methoxy-4a,9b-butano-5H-indeno[1,2-b]pyridine
(+), (-), or (±)-1,2,3,4,5,6-Hexahydro-1-methyl-4a,10b-butanobenz[h]quinoline,
(+), (-), or (±)-1,2,3,4,5,6-Hexahydro-9-methoxy-1-methyl-4a,10b-butanobenz[h]quinoline,
(+), (-), or (±)-1,2,3,4,-Tetrahydro-1-methyl-4a,9b-butano-5H-indeno[1,2-b]pyridine,
(+), (-), or (±)-1,2,3,4,-Tetrahydro-8-methoxy-1-methyl-4a,9b-butano-5H-indeno[1,2-b]pyridine,
(+), (-), or (±)-1,2,3,4,5,6-Hexahydro-4a,10b-butanobenz[h]quinolin-9-ol,
(+), (-), or (±)-1,2,3,4,5,6-Hexahydro-1-methyl-4a,10b-butanobenz[h]quinolin-9-ol,
(+), (-), or (±)-1,2,3,4-Tetrahydro-1a,9b-butano-5H-indeno[1,2-b]pyridin-8-ol, and
(+), (-), or (±)-1,2,3,4-Tetrahydro-1-methyl-4a,9b-butano-5H-indeno[1,2-b]pyridin-8-ol.
Most preferred compounds of the instant invention are:
(+), (-), or (±)-2,3,4,5-Tetrahydro-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-1-methyl-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-1-ethyl-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-1-propyl-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-1-(cyclopropylmethyl)-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-1-phenylmethyl-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-8-methoxy-3a,9b-butano-1H-benz[g]indole,
(+), (-), or (±)-2,3,4,5-Tetrahydro-8-methoxy-1-methyl-3a,9b-butano-1H-benz[g]indole, and
(+), (-), or (±)-2,3,4,5-Tetrahydro-8-methoxy-1-ethyl-3a,9b-butano-1H-benz[g]indole.
Compounds of the instant invention include solvates, hydrates, and pharmaceutically acceptable salts of compounds of formula I above.
The compounds of the present invention contain asymmetric carbon atoms. The instant invention includes the individual enantiomers, which may be prepared or isolated by methods known in the art.
Any resulting racemates can be resolved into the optical antipodes by known methods, for example by separation of the diastereomeric salts thereof, with an optically active acid, and liberating the optically active amine compound by treatment with a base. Racemic compounds of the instant invention can thus be resolved into their optical antipodes e.g., by fractional crystallization of d- or 1- (tartarates, mandelates, or camphorsulfonate) salts. The compounds of the instant invention may also be resolved into the optical antipodes by the formation of diastereomeric carbamates by reacting the compounds of the instant invention with an optically active chloroformate, for example (-)-menthyl chloroformate, or by the formation of a diastereomeric amide by reacting the compounds of the instant invention with an optically active activated carboxy acid such as that derived from (+) or (-) phenylalanine, (+) or (-) phenylglycine, (-)-camphanic acid or the like.
Additional methods for resolving optical isomers, known to those skilled in the art may be used, for example those discussed by J. Jaques, A. Collet, and S. Wilen in "Enantiomers, Racemates and Resolutions", John Wiley and Sons, New York (1981).
The term lower in connection with organic groups, radical or compounds includes up to and including seven members, preferably up to and including four and most preferably one, two, or three carbon atoms except as otherwise specifically described.
Lower alkyl means a straight or branched chain of from one to four carbon atoms including but not limited to methyl, ethyl, propyl, isopropyl, and butyl.
Lower alkenyl means a group from one to four carbon atoms, for example, but not limited to ethylene, 1,2- or 2,3-propylene, 1,2- 2,3-, or 3,4-butylene. Preferred is 2,3-propylene.
Lower alkynyl means a group from one to four carbon atoms, for example, but not limited to ethynyl, 2,3-propynyl, 2,3-, or 3,4-butynyl; propynyl is the preferred group.
Cyclopropylloweralkyl means cyclopropyl-C 1-4 -alkyl, meaning for example, cyclopropylmethyl, 2-(cyclopropyl)ethyl, 3-(cyclopropyl)propyl; cyclopropylmethyl is the preferred group.
Lower alkoxy means a group of from one to four carbon atoms, for example, but not limited to methoxy, ethoxy, propoxy; methoxy is the preferred group.
Halogen is fluorine, chlorine, bromine, or iodine; fluorine, chlorine, and bromine are the preferred groups.
Arylloweralkyl means aryl-C 1-4 -alkyl, meaning for example, benzyl, 2-phenylethyl, 3-phenylpropyl; preferred group is benzyl. The aryl groups may be substituted, for example, by lower alkyl, lower alkoxy, hydroxy, and halogen.
Monoloweralkylamino means a group containing from one to four carbon atoms, for example, but not limited to methylamino, ethylamino, n- or i-(propylamino or butylamino).
Diloweralkylamino means a group containing from one to four carbon atoms in each lower alkyl group, for example, but not limited to dimethylamino, diethylamino, di-(n-propyl)-amino, di-(n-butyl)-amino, or may represent a fused ring, for example piperidine.
Physiologically labile group includes but is not limited to such derivatives described by; I. H. Pitman in Med. Chem. Rev. 2:189 (1981); J. Alexander, R. Cargill, S. R. Michelson and H. Schwam in J. Med. Chem. 31:318 (1988); V. H. Naringrekar and V. J. Stella in European Patent Application 214,009-A2 and include certain amides, such as amides of amino acids, for example glycine, or serine, enaminone derivatives and (acyloxy)alkylcarbamates.
Well-known protecting groups and their introduction and removal are described, for example, in J. F. W. McOmie, Protective Groups in Organic Chemistry, Plenum Press, London, New York (1973), and T. W. Greene, Protective Groups in Organic Synthesis, Wiley, New York (1981).
Salts of the compounds of the invention are preferably pharmaceutically acceptable salts. The compounds of the invention are basic amines from which acid addition salts of pharmaceutically acceptable inorganic or organic acids such as strong mineral acids, for example, hydrohalic, e.g., hydrochloric or hydrobromic acid; sulfuric, phosphoric or nitric acid; aliphatic or aromatic carboxylic or sulfonic acids, e.g., acetic, propionic, succinic, glycolic, lactic, malic, tartaric, gluconic, citric, ascorbic, maleic, fumaric, pyruvic, pamoic, nicotinic, methanesulfonic, ethanesulfonic, hydroxyethanesulfonic, benzenesulfonic, p-toluenesulfonic, or napthlenesulfonic acid can be prepared.
For isolation or purification purposes, salts may be obtained which might not be useful for pharmaceutical purposes. Pharmaceutically acceptable salts useful for therapeutic purposes are preferred.
The present invention also includes processes for making the compounds of formula I above.
One process for the preparation of compounds of formula I is illustrated in Scheme A below. ##STR3##
Step (1) The compound of formula II wherein m is 0 or 1 ##STR4## and R 2 and R 3 are as previously defined are treated with 1,4-dibromobutane under conditions described in Bull. Soc. Chim. France 346 (1957) to give the compounds of the formula III. ##STR5##
Step (2) The compounds of the formula III are treated with lithioacetonitrile, in a solvent such as ether, tetrahydrofuran, or the like, at a temperature between -78° C. and 20° C. to afford the compounds of the formula IV. ##STR6##
Step (3) The compounds of the formula IV are hydrogenated in the presence of a catalyst such as Raney Nickel, or the like, in a solvent such as methanol or ethanol containing ammonia, under a hydrogen atmosphere to give the compounds of the formula V wherein n is 2. ##STR7##
Step (4) Alternatively, the compounds of the formula III are treated with a compound of the formula VI ##STR8## under conditions described by Evans et al in J. Amer. Chem Soc. 371, (1979) or by other methods known to those skilled in the art, such as those described in Tetrahedron 205, (1983) to give the compounds of the formula VII. ##STR9##
Step (5) The compounds of the formula VII are treated with ammonia in a solvent such as toluene, tetrahydrofuran, or the like to give the compounds of the formula VIII. ##STR10##
Step (6) The compounds of the formula VIII are reduced using lithium aluminum hydride, diborane, or the like, in a solvent such as ether, tetrahydrofuran, or the like to give the compounds of the formula V wherein n is 3.
Step (7) The compounds of the formula V are treated with methyl chloroformate, ethyl chloroformate, 2,2,2-trichloroethyl chloroformate or an optically active chloroformate, for example (-)-menthyl chloroformate, (-)-α-methylbenzyl chloroformate or the like, in the presence of a trialkylamine such as triethylamine, tributylamine, diisopropylethylamine or the like, in a solvent such as dichloromethane, chloroform, or the like, to give the compounds of the formula IX wherein R 5 is methyl, ethyl, 2,2,2-trichloroethyl, (-)-menthol, (-)-α-methylbenzyl, or other acid stable protecting group. ##STR11##
Step (8) The compounds of the formula IX are treated with acetic acid, formic acid, triflouroacetic acid, sulfuric acid or the like or combinations thereof, preferably combinations of acetic acid and sulfuric acid to give the compounds of the formula X ##STR12##
Step (9) The compounds of the formula X are treated to remove the carbamate functionalitity using methods known to those skilled in the art for example wherein R 5 is 2,2,2-trichloroethyl the compounds are treated with zinc dust in methanol, ethanol or the like, in the presence of acetic acid, to afford the compounds of the formula I wherein n is 2 or 3, m is 0 or 1, R 1 is hydrogen and R 2 and R 3 are as previously defined.
Step (10) The compounds of the formula I wherein R 1 is hydrogen are treated with an aldehyde such as formaldehyde, acetaldehyde, benzaldehyde or the like or with a ketone such as acetone, acetophenone, or the like, in the presence of a reducing agent such as sodium cyanoborohydride or the like, in a solvent such as methanol, ethanol or the like to give the compounds of the formula I wherein n is 2 or 3, m is 0 or 1, R 1 is as previously defined excepting hydrogen, and R 2 and R 3 are as previously defined.
Step (11) Alternatively the compounds of the formula X are reduced in the presence of lithium aluminum hydride, diborane or the like, in a solvent such as ether, tetrahydrofuran or the like, to afford the compound of the formula I wherein R 1 is methyl.
Novel intermediates useful in the preparation of compounds of formula I are:
Spiro[cyclopentane-1,1'-[1H]inden]-2'(3'H)-one, 7,-methoxy-spiro[cyclopentane-1,1'-[1H]inden]-2'(3'H)-one,
(+), (-), or (±)-3',4'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-napthalen]-2'-acetonitrile,
(+), (-), or (±)-3',4'-dihydro-2'-hydroxy-7'-methoxyspiro[cyclopentane-1,1'(2'H)-napthalen]-2'-acetonitrile,
(+), (-), or (±)-2',3'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'-[1H]inden]-2'-acetonitrile,
(+), (-), or (±)-2',3'-Dihydro-2'-hydroxy-6-methoxyspiro[cyclopentane-1,1'-[1H]inden]-2'-acetonitrile,
(+), (-), or (±)-2'-(2-aminoethyl)-3',4'-dihydrospiro[cyclopentane-1,1'(2H)-napthalen]-2'-ol,
(+), (-), or (±)-2'-(2-aminoethyl)-3',4'-dihydro-7'-methoxyspiro[cyclopentane-1,1'(2'H)-napthalen]-2'-ol, (+), (-), or (±)-2'-(2-aminoethyl)-2',3',-dihydrospiro[cyclopentane-1,1'-[1H]inden-2'-ol,
(+), (-), or (±)-2'-(2-aminoethyl)-2',3'-dihydro-6'-methoxyspiro[cyclopentane-1,1'-[1H]inden-2'-ol,
Ethyl (+), (-), or (±)-[2-(3',4'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-napthalen]-2'yl)ethyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-[2-(3',4'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-naphthalen]-2'-yl)ethyl]carbamate,
(+), (-, ) or (±)-2,2,2-Trichloroethyl-[2-(3',4'-dihydro-2'-hydroxy-7'-methoxyspiro[cyclopentane-1,1'(2'H)-naphthalen]-2'-yl)ethyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-[2-[2',3'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'-[1H]inden]-2'-yl)ethyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-[2-2',3'-dihydro-2'-hydroxy-6'-methoxyspiro[cyclopentane-1,1'-[1H]inden]-2'-yl)ethyl]carbamate,
Ethyl (+), (-), or (±)-2,3,4,5-tetrahydro-3a,9b-butano-1H-benz[g]indole-1-carboxylate,
(+), (-), or (±)-2,2,2-Trichloroethyl-2,3,4,5-tetrahydro-3a,9b-butano-1H-benz[g]indole-1-carboxylate,
(+), (-), or (±)-2,2,2-Trichloroethyl-2,3,4,5-tetrahydro-8-methoxy-3a,9b-butano-1H-benz[g]indole-1-carboxylate,
(+), (-), or (±)-2,2,2-Trichloroethyl-2,3-dihydro-1H,4H-3a,8b-butanoindeno-[1,2-b]pyrrole-1-carboxylate,
(+), (-), or (±)-2,2,2-Trichloroethyl-2,3-dihydro-7-methoxy-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole-1-carboxylate,
(+), (-), or (±)-3',3",4',4"Tetrahydrodispiro[cyclopentane-1,1'(2'H)-napthlene-2',2"(5"H)-furan]-5"-one,
(+), (-), or (±)-3',3",4',4"-Tetrahydro-7'-methoxydispiro[cyclopentane-1,1'(2'H)-napthlene-2',2"(5"H)-furan]-5"-one,
(+), (-), or (±)-3",4"-Dihydrodispiro-[cyclopentane-1,1'-[1H]indene-2'(3'H),2"(5"H)furan]-5"-one,
(+), (-), or (±)-3",4"-Dihydro-6'-methoxydispiro[cyclopentane-1,1'-[1H]indene-2'(3'H),2"(5"H)furan]-5"-one,
(+), (-), or (±)-3',4'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-naphthalene]-2'-propanamide,
(+), (-), or (±)-3',4'-Dihydro-2'-hydroxy-7'methoxyspiro[cyclopentane-1,1'(2'H)-naphthalene]-2'-propanamide,
(+), (-), or (±)-2',3',-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'-[1H]indene]-2'-propanamide,
(+), (-), or (±)-2',3'-Dihydro-2'-hydroxy-6'-methoxyspiro[cyclopentane-1,1'-[1H]indene]-2'-propanamide,
(+), (-), or (±)-2'-(3-aminopropyl)-3',4'-dihydrospiro[cyclopentane-1,1'(2'H)napthalen]-2'-ol,
(+), (-), or (±)-2'-(3-aminopropyl)-3',4'-dihydro-7'-methoxyspiro[cyclopentane-1,1'(2'H)napthalen]-2'-ol,
(+), (-), or (±)-2'-(3-aminopropyl)-2',3'-dihydrospiro[cyclopentane-1,1'-[1H]inden]-2'-ol ,
(+), (-), or (±)-2'-(3-aminopropyl)-2',3'-dihydro-6'-methoxyspiro[cyclopentane-1,1'-[1H]inden]-2'-ol,
(+), (-), or (±)-2,2,2-Trichloroethyl-[3-(3',4'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-napthlene]-2'-yl)propyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-[3-(3',4'-dihydro-2'-hydroxy-7'-methoxyspiro[cyclopentane-1,1'(2'H)-napthlene]-2'-yl)propyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-[3-(2',3'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'-[1H]inden]-2'-yl)propyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-[3-(2',3'-dihydro-2'-hydroxy-6'-methoxyspiro[cyclopentane-1,1'-[1H]inden]-2'-yl)-propyl]carbamate,
(+), (-), or (±)-2,2,2-Trichloroethyl-3,4,5,6-tetrahydro-4a,10b-butanobenz[h]quinoline-1(2H)-carboxylate,
(+), (-), or (±)-2,2,2-Trichloroethyl-3,4,5,6-tetrahydro-9-methoxy-4a,10b-butanobenz[h]quinoline-1(2H)-carboxylate,
(+), (-), or (±)-2,2,2-Trichloroethyl-3,4-dihydro4a,9b-butano-5H-indeno[1,2-b]pyridine-1(2H)-carboxylate, and
(+), (-), or (±)-2,2,2-Trichloroethyl-3,4-dihydro-8-methoxy-4a,9b-butano-5H-indeno[1,2-b]pyridine-1(2H)-carboxylate.
The compounds of the instant invention exhibit valuable pharmacological properties by selectively blocking the N-methyl-D-aspartate sensitive excitatory amino acid receptors in mammals. The compounds are thus useful for treating diseases responsive to excitatory amino acid blockade in mammals.
The effects are demonstrable in in vitro tests or in vivo animal tests using mammals or tissues or enzyme preparations thereof, e.g., mice, rats, or monkeys. The compounds are administered enterally or parenterally, for example, orally, transdermally, subcutaneously, intravenously, or intraperitoneally. Forms include but are not limited to gelatin capsules, or aqueous suspensions or solutions. The applied in vivo dosage may range between about 0.01 to 100 mg/kg, preferably between about 0.05 and 50 mg/kg, most preferably between about 0.1 and 10 mg/kg.
The ability of the compounds of the instant invention to interact with phencyclidine (PCP) receptors which represents a noncompetitive NMDA antagonist binding site, is shown by Examples 23 and 27 which bind with an affinity of less than 10 μM. Tritiated 1-[1-(2-thienyl)cyclohexyl]pipiridine (TCP) binding, designated RBS1, was carried out essentially as described in J. Pharmacol. Exp. Ther. 238, 739 (1986).
For medical use, the amount required of a compound of formula I or pharmacologically acceptable salt thereof--(hereinafter referred to as the active ingredient) to achieve a therapeutic effect will, of course, vary both with the particular compound, the route of administration and the mammal under treatment and the particular disorder or disease concerned. A suitable systemic dose of a compound of formula I or pharmacologically acceptable salt thereof for a mammal suffering from, or likely to suffer from any condition as described herein before is in the range 0.01 to 100 mg of base per kilogram body weight, the most preferred dosage being 0.05 to 50 mg/kg of mammal body weight.
It is understood that the ordinarily skilled physician or veterinarian will readily determine and prescribe the effective amount of the compound for prophylactic or therapeutic treatment of the condition for which treatment is administered. In so proceeding, the physician or veterinarian could employ an intravenous bolus followed by intravenous infusion and repeated administrations, parenterally or orally, as considered appropriate.
While it is possible for an active ingredient to be administered alone, it is preferable to present it as a formulation.
Formulations of the present invention suitable for oral administration may be in the form of discrete units such as capsules, cachets, tablets, or lozenges, each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution or a suspension in an aqueous liquid or nonaqueous liquid; or in the form of an oil-in-water emulsion or a water-in-oil emulsion. The active ingredient may also be in the form of a bolus, electuary, or paste.
A tablet may be made by compressing or molding the active ingredient optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, surface active, or dispersing agent. Molded tablets may be made by molding, in a suitable machine, a mixture of the powdered active ingredient and a suitable carrier moistened with an inert liquid diluent.
Formulations suitable for parenteral administration conveniently comprise a sterile aqueous preparation of the active ingredient which is preferable isotonic with the blood of the recipient.
Formulations suitable for nasal or buccal administration (such as self-propelling powder dispensing formulations described hereinafter), may comprise 0.1 to 20% w/w, for example, 2% w/w of active ingredient.
The formulations, for human medical use, of the present invention comprise an active ingredient in association with a pharmaceuticaly acceptable carrier therefor and optionally other therapeutic ingredient(s). The carrier(s) must be `acceptable` in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof.
So the pharmacologically active compounds of the invention are useful in the manufacture of pharmaceutical compositions comprising an effective amount thereof in conjunction or admixture with excipients or carriers suitable for either enteral or parenteral application. Preferred are tablets and gelatin capsules comprising the active ingredient together with a) diluents, e.g. lactose, dextrose, sucrose, mannitol, sorbitol, cellulose, and/or glycine; b) lubricants, e.g. silica, talcum, stearic acid, its magnesium or calcium salt, and/or polyethyleneglycol; for tablets also c) binders e.g. magnesium aluminum silicate, starch paste, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose and/or polyvinylpyrrolidone; if desired d) disintegrants, e.g. starches, agar, alginic acid, or its sodium salt, or effervescent mixtures; and/or e) absorbents, colorants, flavors, and sweeteners. Injectable compositions are preferably aqueous isotonic solutions or suspensions, and suppositories are advantageously prepared from fatty emulsions, or suspensions. Said compositions may be sterilized and/or contain adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure, and/or buffers. In addition, they may also contain other therapeutically valuable substances. Said compositions are prepared according to conventional mixing, granulating, or coating methods, respectively, and contain about 0.1 to 75%, preferably about 1 to 50%, of the active ingredient.
The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well-known in the art of pharmacy. All methods include the step of bringing the active ingredient into association with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing the active ingredient into association with a liquid carrier or a finely divided solid carrier or both, and then, if necessary, shaping the product into the desired formulation.
The following examples are illustrative of the present invention but are not intended to limit it in any way.
EXAMPLE 1 ##STR13##
3',4'-Dihydrospiro[cyclopentane-1,1'(2'H)-napthlen]-2'-one
A suspension of KOt-Bu (76.3 g, 0.68 mol) in 500 mL of xylene was treated dropwise with 2-tetralone (50 g, 0.34 mol). The resulting solution was treated dropwise with 1,4-dibromobutane (74.0 g, 0.34 mol) (exothermic reaction). The resulting suspension was heated to reflux for 18h. The reaction mixture was treated with water (200 mL) and the organic phase was collected. The aqueous phase was extracted with ethyl acetate (2×200 mL) and the combined organic extracts were dried (MgSO 4 ), filtered and concentrated. Distillation of the residue provided the product (65.6 g, 96%) as a colorless liquid.
EXAMPLE 2 ##STR14##
3',4'-Dihydro-7'-methoxyspiro-8 cyclopentane-1,1'(2'H)-napthlen]-2'-one
In a manner similar to that described in Example 1, 7-methoxy-2-tetralone (20.0 g, 0.113 mol) was converted to the title compound (10.3 g, 40%) as a colorless oil.
EXAMPLE 3 ##STR15##
Spiro[cyclopentane-1,1'-[1H]inden]-2'(3'H)-one
In a manner similar to that described in Example 1, 2-indanone is converted to the title compound.
EXAMPLE 4 ##STR16##
6'-Methoxy-spiro[cyclopentane-1,1'-[1H]inden]-2'(3'H)-one
In a manner similar to that described in Example 1, 5-methoxy-2-indanone is converted to the title compound.
EXAMPLE 5 ##STR17##
(±)-3',4'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-napthalen]-2'-acetonitrile
A solution of acetonitrile (1.1 g, 27.5 mmol) in 100 mL of anhydrous tetrahydrofuran (THF) was cooled to -78° C. and treated with lithium diisopropylamide (18 mL of a 1.5 M solution in tetrahydrofuran). The resulting suspension was stirred at -78° C. for 30 minutes and treated dropwise with a solution of the product from Example 1 (5.0 g, 24.9 mmol) in 10 mL of anhydrous THF. The resulting solution was warmed to room temperature and saturated aq. NH 4 Cl solution (15 mL) was added. The organic phase was collected and the aqueous phase was extracted with ether (3×50 mL). The combined organic phases were dried (MgSO 4 , filtered and concentrated. The solid which formed was suspended in diisopropyl ether and collected by suction filtration. The material was dried under vacuum to give the title compound (4.14 g, 69%) as a white solid mp 165°-166° C.
Anal. (C 16 H 19 NO) Calc'd: C, 79.63; H, 7.94; N, 5.80 Found: C, 79.72; H, 7.86; N, 5.81
EXAMPLE 6 ##STR18##
(±)-3',4'-Dihydro-2, hydroxy-7'-methoxyspiro[cyclopentane-1,1'(2'H)-napthalen]-2'-acetonitrile
In a manner similar to that described in Example 5, the product of Example 2 (10.0 g, 43.4 mmol) was converted to the title compound (4.33 g, 37%) as a tan solid mp 126°-127° C.
Anal. (C 17 H 21 NO 2 ) Calc'd C, 75.25; H, 7.80; N, 5.16 Found: C, 75.36; H, 7.67; N, 4.94
EXAMPLE 7 ##STR19##
(±)-2',3'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'-[1H]inden]-2'-acetonitrile
In a manner similar to that described in Example 5, the product of Example 3 is converted to the title compound.
EXAMPLE 8 ##STR20##
(±)-2',3'-Dihydro-2'-hydroxy-6-methoxyspiro[cyclopentane-1,1'-[1H]inden]-2'-acetonitrile
In a manner similar to that described in Example 5, the product of Example 4 is converted to the title compound.
EXAMPLE 9 ##STR21##
(±)-2'-(2-Aminoethyl)-3',4'-dihydrospiro[cyclopentane-1,1'(2'H)-napthalen]-2'-ol
A solution of the product from Example 5 (2.50 g, 10.3 mmol) in 100 mL of methanolic ammonia was hydrogenated over Raney nickel (2.0 g) at 52 psi for 7.5 hours. The reaction mixture was filtered to remove the catalyst and the filtrate concentrated to give the title compound (2.59 g, quantitative) as a pale green solid mp 107°-109° C.
Anal. (C 16 H 23 NO) Calc'd: C, 79.63; H, 7.94; N, 5.81 Found: C, 79.37; H, 8.02; N, 5.59
EXAMPLE 10 ##STR22##
(±)-2'-(2-Aminoethyl)-3',4'-dihydro-7'-methoxyspiro[cyclopentane-1,1(2'H)-napthalen]-2'-ol
In a manner similar to that described for Example 9, the product of Example 6 (4.85 g, 17.9 mmol) was hydrogenated to give the title compound (4.86 g, 99%) as a pale green solid.
Anal. (C 17 H 25 NO 2 ) Calc'd: C, 74.14; H, 9.15; N, 5.08 Found C, 73.40; H, 9.19; N, 5.04
EXAMPLE 11 ##STR23##
(±)-2'-(2-Aminoethyl)-2',3'-dihydrospiro[cyclopentane-1,1'-[1H]inden-2'-ol
In a manner similar to that described for Example 9, the product of Example 7 is hydrogenated to give the title compound.
EXAMPLE 12 ##STR24##
(±)-2'-(2-Aminoethyl)-2',3'-dihydro-6'-methoxyspiro-[cyclopentane-1,1'-[1H]inden-2'-ol
In a manner similar to that described for Example 9, the product of Example 8 is hydrogenated to give the title compound.
EXAMPLE 13 ##STR25##
Ethyl (±)-[2-(3',4'-dihydro-2'-hydroxyspiro-[cyclopentane-1,1'(2'H)-napthalen]-2'-yl)ethyl]-carbamate
A solution of the product from Example 9 (1.05 g, 4.28 mmol) and triethylamine (0.44 g, 4.35 mmol) in 10 mL of CH 2 Cl 2 was cooled to 0° C. and ethyl chloroformate (0.47 g, 4.33 mmol) in 5 mL CH 2 Cl 2 was added dropwise. The reaction was warmed to room temperature and washed with water. The aqueous phase was extracted with CH 2 Cl 2 (3×20 mL) and the combined organic extracts were dried (MgSO 4 ), filtered and concentrated. The residue was purified by chromatography (silica gel, 1:1 heptane/ethyl acetate) to give the title compound (1.33 g, 98%) as an oil.
EXAMPLE 14 ##STR26##
2,2,2-Trichloroethyl (±)-[2-(3',4'-dihydro-2'-hydroxyspiro-8 cyclopentane-1,1'(2'H)-naphthalen]-2'yl)ethyl]carbamate
A solution of the product from Example 9 (0.88 g, 3.59 mmol) and triethylamine (0.40 g, 3.78 mmol) in 10 mL of CH 2 Cl 2 was cooled to 0° C. and treated dropwise with 2,2,2-trichloroethylchloroformate (0.80 g, 3.78 mmol) in 2 mL CH 2 Cl 2 . The resulting solution was stirred at 0° C. for 30 minutes and warmed to room temperature. The reaction mixture was washed with saturated aq. NaHCO 3 solution (10 mL). The aqueous phase was extracted with CH 2 Cl 2 (10 mL). The combined organic extracts were dried (MgSO 4 ), filtered and concentrated. The residue was purified by chromatography (silica gel, 10:1 heptane/ethyl acetate) to give the title compound (1.18 g, 78%) as a viscous oil.
EXAMPLE 15 ##STR27##
2,2,2-Trichloroethyl (±)-[2-(3',4'-dihydro-2'-hydroxy-7'-methoxyspiro[cyclopentane-1,1'(2'H)-naphthalen]-2'-yl)ethyl]carbamate
In a manner similar to that described in Example 14, the product of Example 10 (4.66 g, 16.9 mmol) is converted to the title compound (6.81 g, as a foamy white solid.
EXAMPLE 16 ##STR28##
2,2,2-Trichloroethyl (±)-[2-[2',3'-dihydro-2'-hydroxy-spiro[cyclopentane-1,1'-[1H]inden]-2'-yl)ethyl]carbamate
In a manner similar to that described in Example 14, the product of Example 11 is converted to the title compound.
EXAMPLE 17 ##STR29##
2,2,2-Trichloroethyl (±)-[2-[2',3'-dihydro-2'-hydroxy-6'-methoxyspiro[cyclopentane-1,1'-[1H]inden]-2'-yl)ethyl]carbamate
In a manner similar to that described in Example 14, the product of Example 12 is converted to the title compound.
EXAMPLE 18 ##STR30##
Ethyl (±)-2,3,4,5-tetrahydro-3a,9b-butano-1H-benz[g]indole-1-carboxylate
A solution of the product from Example 13 (1.68 g, 5.29 mmol) in 15 mL of 3:1 acetic acid/concentrated sulfuric acid (v/v) was stirred at room temperature for 18 hours. The reaction mixture was poured into water (50 mL) and the resulting mixture was extracted with CH 2 Cl 2 (4×30 mL). The combined organic extracts were dried (MgSO 4 ), filtered and concentrated. The residue was dissolved in CH 2 Cl 2 (100 mL and washed with saturated aq. bicarbonate solution (30 mL). The organic phase was dried (MgSO 4 ), filtered and concentrated. The residue was purified by chromatography (silica gel, 9:1 heptane/ethyl acetate) to give the title compound (0.94 g, 59%) as a white solid mp 67°-69° C.
Anal. (C 19 H 25 NO 2 ) Calc'd: C, 76 22; H, 8.42; N, 4.68 Found: C, 75.99; H, 8.38; N, 4.41
EXAMPLE 19 ##STR31##
2,2,2-Trichloroethyl (±)-2,3,4,5-tetrahydro-3a,9b-butano-1H-benz[g]indole-1-carboxylate
In a manner similar to that described in Example 18, the product of Example 14 (0.98 g, 2.33 mmol) was converted to the title compound (0.71 g, 76%) as an oil.
EXAMPLE 20 ##STR32##
2,2,2-Trichloroethyl (±)-2,3,4,5-tetrahydro-8-methoxy-3a,9b-butano-1H-benz[g]indole-1-carboxylate
In a manner similar to that described in Example 18, the product of Example 15 (5.16 g, 11.4 mmol) was converted to the title compound (4.18 g, 84%) as an oil.
EXAMPLE 21 ##STR33##
2,2,2-Trichloroethyl (±)-2,3-dihydro-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole-1-carboxylate
In a manner similar to that described in Example 18, the product of Example 16 is converted to the title compound.
EXAMPLE 22 ##STR34##
2,2,2-Trichloroethyl (±)-2,3-dihydro-7-methoxy-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole-1-carboxylate
In a manner similar to that described in Example 18, the product of Example 17 is converted to the title compound.
EXAMPLE 23 ##STR35##
(±)-2,3,4,5-Tetrahydro-3a,9b-butano-1H-benz[g]indole hydrochloride
A solution of the product from Example 19 (0.70 g, 1.74 mmol) in 20 mL of methanol and 0.5 mL acetic acid was treated with zinc dust (1.58 g, 320 mesh) and the resulting suspension stirred at room temperature for three hours. The reaction mixture was filtered and the filtrate concentrated. The residue was dissolved in ether (30 mL) and extracted with aqueous 1N HCl (3×15 mL). The combined acid extracts are made basic (pH=11) with potassium carbonate and the resulting aqueous solution was extracted with CH 2 Cl 2 (5×15 mL). The combined organic extracts were dried (Na 2 SO 4 , filtered and concentrated. The residue (0.30 g) was converted to its HCl salt by dissolution in ether and treatment with a saturated solution of HCl (gas) in ether. The solid which formed was collected by filtration and dried under vacuum (100° C.) to give the title compound (0.25 g, 54%) as a white solid mp >270° C.
Anal (C 16 H 19 N.HCl) Calc'd: C, 72.85; H, 8.40; N, 5.31; Cl, 13.44 Found: C, 72.66; H, 8.38, N, 4.98; Cl, 13.83
EXAMPLE 24 ##STR36##
(±)-2,3,4,5-Tetrahydro-8-methoxy-3a,9b-butano-1H-benz[g]indole
In a manner similar to that described in Example 23, the product of Example 20 (3.76 g, 8.67 mmol) was converted to the title compound (1.47 g, 70%) as an oil. An analytical sample was prepared by crystallization of the fumarate salt from acetaone which gave a white solid mp 203°-204° C.
Anal. (C 17 H 23 NO.C 4 H 4 O 4 ) Calc'd: C, 67.54; H, 7.29; N, 3.75 Found: C, 67.55; H, 7.18; N, 3.61
EXAMPLE 25 ##STR37##
(±)-2,3-Dihydro-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole
In a manner similar to that described in Example 23, the product of Example 21 is converted to the title compound.
EXAMPLE 26 ##STR38##
(±)-2,3-Dihydro-7-methoxy-1H,4H-3a,8b-butanoindeno-[1,2-b1pyrrole
In a manner similar to that described in Example 23, the product of Example 22 is converted to the title compound.
EXAMPLE 27 ##STR39##
(±)-2,3,4,5-Tetrahydro-1-methyl-3a,9b-butano-1H-benz[g]indole hydrochloride
A solution of the product from Example 18 (0.77 g, 2.56 mmol) in 5 mL of THF was added dropwise to a suspension of lithium aluminum hydride (0.76 g, 20.0 mmol) in 15 mL of THF. The reaction mixture was stirred at room temperature for 18 hours and then heated to reflux for 1 hour. The reaction mixture was cooled to room temperature and quenched by the addition of small portions of Na 2 SO 4 -10H 2 O until no further gas evolution was observed. The reaction mixture was filtered and the filtrate was concentrated. The residue was dissolved in ether and treated with a saturated solution of dry HCl in ether. The solid which formed was collected by suction filtration and dried under vacuum (100° C.) to give the product (0.51 g, 72%) as a white solid mp 241°-253° C.
Anal. (C 17 H 23 N.HCl) Calc'd: C, 73.49; H, 8.71; N, 5.04; Cl, 12.76 Found: C, 73.39; H, 8.73; N, 4.82; Cl, 13.16
EXAMPLE 28 ##STR40##
(±)-2,3,4,5-Tetrahydro-8-methoxy-1-methyl-3a,9b-butano-1H-benz[g]indole
A solution of the product from Example 24 (0.79 g, 3.08 mmol) and sodium cyanoborohydride (0.80 g, 12.7 mmol) in 10 mL methanol was treated dropwise with a 37% aqueous formalin solution (5 mL). The resulting solution was stirred at room temperature for 30 minutes, concentrated, and partitioned between 1N HCl (20 mL) and ether (20 mL). The organic phase was extracted with IN HCl (2×10 mL) and the combined aqueous extracts were washed with ether. The aqueous phase was made basic with K 2 CO 3 and extracted with CH 2 Cl 2 (3×20 mL). The combined organic extracts were dried K 2 CO 3 , filtered and concentrated to give the title compound (0.87 g, quantitative) as a white solid mp 100°-102° C.
Anal. (C 18 H 25 NO) Calc'd: C, 79.66; H, 9.29; N, 5.16 Found: C, 79.52; H, 9.53; N, 4.71
EXAMPLE 29 ##STR41##
(±)-2,3-Dihydro-1-methyl-1H,4H-3a,8b-butanoindeno-[1,2-b]pyrrole
In a manner similar to that described in Example 28, the product of Example 25 is converted to the title compound.
EXAMPLE 30 ##STR42##
(±)-2,3-Dihydro-7-methoxy-1-methyl-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrole
In a manner similar to that described in Example 28, the product of Example 26 is converted to the title compound.
EXAMPLE 31 ##STR43##
(±)-2,3,4,5-Tetrahydro-1-ethyl-3a,9b-butano-1H-benz[g]indole fumarate
In a manner similar to that described in Example 28, the product from Example 23 (0.30 g, 1.32 mmol) and sodium cyanoborohydride (0.30 g, 4.77 mmol) was treated dropwise with acetaldehyde (0.20 g, 4.10 mmol) in 5 mL of methanol. Workup followed by crystallization of the fumarate salt from acetone gave the title compound (0.32 g, 65%) as a white solid mp 172°-173° C.
Anal. (C 18 H 25 N.C 4 H 4 O 4 ) Calc'd: C, 71 13; H, 7.87; N, 3.77 Found: C, 70.90: H, 7.79; N, 3.75
EXAMPLE 32 ##STR44##
(±)-2,3,4,5-Tetrahydro-8-methoxy-1-ethyl-3a,9b-butano-1H-benz[g]indole hydrobromide
In a manner similar to that described in Example 31, the product of Example 24 (0.27 g, 1.13 mmol) and acetaldehyde (0.32 g, 7.12 mmol) are reacted. Workup, followed by crystallization from ether and HBr gave the title compound (0.27 g, 64%) as a white solid mp 248°-251° C.
Anal. (C 19 H 27 NO.HBr) Calc'd: C, 62.29; H, 7.71; N, 3.82; Br, 21.81 Found: C, 62.39; H, 7.65; N, 3.77; Br, 21.98
EXAMPLE 33 ##STR45##
(±)-2,3,4,5-Tetrahydro-1-propyl-3a,9b-butano-1H-benz[g]indole hydrobromide
In a manner similar to that described in Example 32, the product from Example 23 (0.25 g, 1.10 mmol) and propionaldehyde (0.20 g, 3.47 mmol) was converted to the title compound (0.23 g, 60%) as a white solid mp 196`-198° C.
Anal. (C 19 H 27 N.HBr) Calc'd: C, 64.92; H, 8.13; N, 4.07; Br, 23.09 Found C, 65.14; H, 8.06; N, 4.00; Br, 22.80
EXAMPLE 34 ##STR46##
(±)-2,3,4,5-tetrahydro-1-(cyclopropylmethyl)-3a,9b-butano-1H-benz[g]indole fumarate
In a manner similar to that described in Example 31, the product from Example 23 (0.25 g, 1.10 mmol) and cyclopropanecarboxaldehyde (0 23 g, 1.10 mmol) was converted to the title compound (0.26 g, 58%) as a white solid mp 150°-152° C.
Anal. (C 20 H 27 N.1.2.C 4 H 4 O 4 ) Calc'd: C, 70.80; H, 7.62; N, 3.33 Found: C, 71.05; H, 7.67, N, 3.32
EXAMPLE 35 ##STR47##
(±)-2,3,4,5-tetrahydro-1-phenylmethyl-3a,9b-butano-1H-benz[g]indole hydrochloride
In a manner similar to that described in Example 32, the product from Example 23 (0.34 g, 1.50 mmol) and benzaldehyde are reacted. Workup, followed crystallization from ether and HCl gave the title compound (0 22 g, 42%) as a white solid mp 235-237° C.
Anal. (C 23 H 27 N.HCl) Calc'd: C, 78.05; H, 7.98; N, 3.96; Cl, 10.02 Found: C, 77.60; H, 8.00, N, 3.34; Cl, 10.24
EXAMPLE 36 ##STR48##
(±)-2,3,4,5-Tetrahydro-1-(2-propenyl)-3a,9b-butano-1H-benz[g]indole
In a manner similar to that described in Example 32, the product from Example 23 is converted to the title compound.
EXAMPLE 37 ##STR49##
(±)-2,3,4,5-Tetrahydro-3a,9b-butano-1H-benz[g]indol-8-ol
A solution of the product from Example 24 is heated to reflux in 48% aqueous HBr until the starting material is consumed. The reaction mixture is poured into cold NH 4 OH solution and extracted into ethyl acetate. The combined organic extracts are dried (Na 2 SO 4 ) and concentrated to give the title compound.
EXAMPLE 38 ##STR50##
(±)-2,3,4,5-Tetrahydro-1-methyl-3a,9b-butano-1H-benz[g]indol-8-ol
In a manner similar to that described in Example 37, the product from Example 28 is converted to the title compound.
EXAMPLE 39 ##STR51##
(±)-2,3-Dihydro-1H,4H-3a,8b-butanoindeno[1,2-b]pyrrol-7-ol
In a manner similar to that described in Example 37, the product from Example 26 is converted to the title compound.
EXAMPLE 40 ##STR52##
(±)-2,3-Dihydro-1-methyl-1H,4H-3a,8b-butanoindeno[1,2-b]-pyrrol-7-ol
In a manner similar to that described in Example 37, the product from Example 30 is converted to the title compound.
EXAMPLE 41 ##STR53##
3',3",4',4"-Tetrahydrodispiro[cyclopentane-1,1'(2'H)-napthlene-2',2"(5"H)-furan]-5"-one
A solution of triethylsilyl N,N,N',N'-tetramethyl phosphoramidate (J. Amer. Chem. Soc. 1978, 100, 3468) (1.1 eq.) in anhydrous ether is cooled to 0° C. and treated with acrolein (1.0 eq.) in anhydrous ether. The resulting solution is stirred at 0° C. for 4.5 hours then cooled to -78° C. and a solution of n-butyllithium (1.0 eq.) is added. The resulting solution is treated with the product from Example 1 (1.0 eq.) and stirred at -78° C. for several hours. The reaction mixture is quenched with brine and extracted with several portions of ether. The combined extracts are dried and concentrated. The residue is dissolved in THF and cooled to 0° C. and tetra-n-butylammonium flouride (5 eq.) is added. The reaction mixture is warmed to room temperature and worked up as above to give the title compound.
EXAMPLE 42 ##STR54##
3',3",4',4"-Tetrahydro-7, methoxydispiro-[cyclopentane-1,1'(2'H)-napthlene-2',2"(5"H)-furan1-5"-one
In a manner similar to that described in Example 41, the product from Example 2 is converted to the title compound.
EXAMPLE 43 ##STR55##
3",4"-Dihydrodispiro[cyclopentane-1,1'-[1H]indene-2'(3'H),2"(5"H)-furan]-5"-one
In a manner similar to that described in Example 41, the product from Example 3 is converted to the title compound.
EXAMPLE 44 ##STR56##
3",4"-Dihydro-6'-methoxydispiro[cyclopentane-1,1'-[1H]indene-2'(3'H),2"(5"H)-furan]-5"-one
In a manner similar to that described in Example 41, the product from Example 4 is converted to the title compound.
EXAMPLE 45 ##STR57##
(±)-3',4'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-naphthalene]-2'-propanamide
A solution of the product from Example 41 is placed in a high pressure reactor and dissolved in tetrahydrofuran. Ammonia is condensed into the solution and the reaction vessel is sealed and the reaction mixture is stirred at room temperature for approximately 24 hours. The reaction vessel is vented and the remaining solvent is concentrated to give the title compound.
EXAMPLE 46 ##STR58##
(±)-3',4'-Dihydro-2'-hydroxy-7'-methoxyspiro-[cyclopentane-1,1'(2'H)-naphthalene]-2'-propanamide
In a manner similar to that described in Example 45, the product from Example 42 is converted to the title compound.
EXAMPLE 47 ##STR59##
(±)-2',3'-Dihydro-2'-hydroxyspiro[cyclopentane-1,1'-[1H1indene]-2'-propanamide
In a manner similar to that described in Example 45, the product from Example 43 is converted to the title compound.
EXAMPLE 48 ##STR60##
(±)-2',3,-Dihydro-2'-hydroxy-6'-methoxyspiro[cyclopentane-1,1'-[1H]indene]-2'-propanamide
In a manner similar to that described in Example 45, the product from Example 44 is converted to the title compound.
EXAMPLE 49 ##STR61##
(±)-2'-(3-Aminopropyl)-3',4'-dihydrospiro[cyclopentane-1,1'(2'H)napthalen]-2'-ol
A solution of the product from Example 45, in tetrahydrofuran (THF) is added dropwise to a suspension of lithium aluminumhydride in THF. The resulting suspension is heated to reflux for 1 hour and then stirred at room temperature for 18 hours. The reaction mixture is quenched by the addition of small portions of Na 2 SO 4 -10H 2 O until no more gas evolution is observed. The resulting suspension is filtered and the filtrate is concentrated to give the title compound.
EXAMPLE 50 ##STR62##
(±)-2'-(3-Aminopropyl)-3',4'-dihydro-7',-methoxyspiro[cyclopentane-1,1'(2'H)napthalen]-2'-ol
In a manner similar to that described in Example 49, the product from Example 46 is converted to the title compound.
EXAMPLE 51 ##STR63##
(±)-2'-(3-Aminopropyl)-2',3'-dihydrospiro-[cyclopentane-1,1'-[1H]inden]-2'-ol
In a manner similar to that described in Example 49, the product from Example 47 is converted to the title compound.
EXAMPLE 52 ##STR64##
(±)-2'-(3-Aminopropyl)-2',3'-dihydro-6'-methoxyspiro[cyclopentane-1,1'(2',H)-NAPTHLENE]-2'-yl)propyl]carbamate
In a manner similar to that described in Example 49, the product from Example 48 is converted to the title compound.
EXAMPLE 53 ##STR65##
2,2,2-Trichloroethyl (±)-[3-(3',4'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'(2'H)-napthlene]-2'-yl)propyl[carbamate
A solution of the product from Example 49 (1.0 eq.) and triethylamine (1.1 eq.) in CH 2 Cl 2 is cooled to 0° C. and a solution of 2,2,2-trichloroethylchloroformate (1.1 eq.) in CH 2 Cl 2 is added dropwise. The resulting solution is stirred at 0° C. for 30 minutes and warmed to room temperature. The reaction mixture is washed with bicarbonate, dried and concentrated t give the title compound.
EXAMPLE 54 ##STR66##
2,2,2-Trichloroethyl (±)-[3-(3',4'-dihydro-2'-hydroxy-7'-methoxyspiro[cyclopentane-1,1'(2'H)napthlene]-2'-yl)propyl]carbamate
In a manner similar to that described in Example 53, the product from Example 50 is converted to the title compound.
EXAMPLE 55 ##STR67##
2,2,2-Trichloroethyl (±)-[3-(2',3'-dihydro-2'-hydroxyspiro[cyclopentane-1,1'[1H]inden]-2'yl)propyl]carbamate
In a manner similar to that described in Example 53, the product from Example 51 is converted to the title compound.
EXAMPLE 56 ##STR68##
2,2,2-Trichloroethyl (±)-[3-(2',3'-dihydro-2'-hydroxy-6'-methoxyspiro[cyclopentane-1,1'[1H]inden]-2'-yl)propyl]carbamate
In a manner similar to that described in Example 53, the product from Example 52 is converted to the title compound.
EXAMPLE 57 ##STR69## 2,2,2-Trichloroethyl (±)-3,4,5,6-tetrahydro-4a,10b-butanobenz[h]quinoline-1(2H)-carboxylate
In a manner similar to that described in Example 18, the product from Example 53 is converted to the title compound.
EXAMPLE 58 ##STR70##
2,2,2-Trichloroethyl (±)-3,4,5,6-tetrahydro-9-4a,10b-butanobenz[h]quinoline-1(2H)-carboxylate
In a manner similar to that described in Example 18, the product from Example 54 is converted to the title compound.
EXAMPLE 59 ##STR71##
2,2,2-Trichloroethyl (±)-3,4-dihydro-4a,9b-butano-5H-indeno[1,2-b]pyridine-1(2H)-carboxylate
In a manner similar to that described in Example 18, the product from Example 55 is converted to the title compound.
EXAMPLE 60 ##STR72##
2,2,2-Trichloroethyl (±)-3,4-dihydro-8-methoxy-4a,9b-butano-5H-indeno[1,2-b]pyridine-1(2H)-carboxylate
In a manner similar to that described in Example 18, the product from Example 56 is converted to the title compound.
EXAMPLE 61 ##STR73##
(±)-1,2,3,4,5,6-Hexahydro-4a,10b-butanobenz[h]-quinoline
In a manner similar to that described in Example 23, the product from Example 57 is converted to the title compound.
EXAMPLE 62 ##STR74##
(±)-1,2,3,4,5,6-Hexahydro-9-methoxy-4a,10b- butanobenz[h]-quinoline
In a manner similar to that described in Example 23, the product from Example 58 is converted to the title compound.
EXAMPLE 63 ##STR75##
(±)-1,2,3,4-Tetrahydro-4a,9b-butano-5H-indeno[1,2-b]pyridine
In a manner similar to that described in Example 23, the product from Example 59 is converted to the title compound.
EXAMPLE 64 ##STR76##
(±)-1,2,3,4-Tetrahydro-8-methoxy-4a,9b-butano-5H-indeno[1,2-b]pyridine
In a manner similar to that described in Example 23, the product from Example 60 is converted to the title compound.
EXAMPLE 65 ##STR77##
(±)-1,2,3,4,5,6-Hexahydro-1-methyl-4a,10b-butanobenz[h]quinoline
In a manner similar to that described in Example 28, the product from Example 61 is converted to the title compound.
EXAMPLE 66 ##STR78##
(±)-1,2,3,4,5,6-Hexahydro-9-methoxy-1-methyl-4a,10b-butanobenz[h]quinoline
In a manner similar to that described in Example 28, the product from Example 62 is converted to the title compound.
EXAMPLE 67 ##STR79##
(±)-1,2,3,4-Tetrahydro-1-methyl-4a,9b-butano-5H-indeno[1,2-b]pyridine
In a manner similar to that described in Example 28, the product from Example 63 is converted to the title compound.
EXAMPLE 68 ##STR80##
(±)-1,2,3,4-Tetrahydro-8-methoxy-1-methyl-4a,9b-butano-5H-indeno[1,2-b]pyridine
In a manner similar to that described in Example 28, the product from Example 64 is converted to the title compound.
EXAMPLE 69 ##STR81##
(±)-1,2,3,4,5,6-Hexahydro-4a,10b-butanobenz[h]quinoline-9-ol
In a manner similar to that described in Example 37, the product from Example 62 is converted to the title compound.
EXAMPLE 70 ##STR82##
(±)-1,2,3,4,5,6-Hexahydro-1-methyl-4a,10b-butanobenz[h]quinoline-9-ol
In a manner similar to that described in Example 37, the product from Example 64 is converted to the title compound.
EXAMPLE 71 ##STR83##
(±)-1,2,3,4-Tetrahydro-4a,9b-butano-5H-indeno[1,2-b]pyridin-8-ol
In a manner similar to that described in Example 37, the product from Example 66 is converted to the title compound.
EXAMPLE 72 ##STR84##
(±)-1,2,3,4-Tetrahydro-1-methyl-4a,9b-butano-5H-indeno[1,2-b]pyridin-8-ol
In a manner similar to that described in Example 37, the product from Example 68 is converted to the title compound. | A novel series of tetracyclic amines, methods of preparation, compositions containing the amines, and methods for using them in the treatment and/or prevention of cerebrovascular disorders are disclosed. | 2 |
BACKGROUND OF THE INVENTION
In the typical conventional incandescent light bulb a resistor which will glow incandescently when served with electricity is encapsulated within an evacuated or noble gas-filled glass envelope. Two leads to opposite ends of the resistor sealingly pierce the glass envelope. Usually the bulb is provided with a fitting which combines a mechanical mounting means for the bulb as well as electrical terminals for the two leads, separated by a body of electrically insulating material. Typically the glowing resistor is provided in the form of one or more very fine filamentary strands of a tough, ductile metal such as tungsten. One or both leads of the incandescent filament may incorporate a fuse which is arranged to interrupt or irreversibly sever the electrical circuit through the bulb should an abnormally high voltage be placed across the bulbs leads. Most frequently on incandescent electric light bulbs meant for household and office interior lighting the single fitting of the bulb takes the form of an externally threaded cylindrical base securely externally mounted to the glass envelope. On such bulbs, usually one resistor lead is terminated to the screw-threaded metal collar which forms the sidewall of the base and the other resistor lead is terminated to a boss that is centrally located on the outer end wall of the base. Dielectric material is provided in an annulus closing the space between the boss and the metal collar at the outer end of the bulb base.
In order to use such a bulb, generally it is necessary to screw its base into a socket which has two corresponding, electrically isolated center and peripheral terminals.
Where two or more such bulbs are to be connected in the same electrical circuit, conventionally it is necessary to wire a corresponding number of sockets into the same circuit, and to screw the base of a respective bulb into each. Although the sockets may be serially wired along the circuit, more typically each is wired across the circuit, particularly so that if the light-producing element of one bulb fails the circuit will not be interrupted as to the remaining bulbs and they will continue to be served with electricity.
Although they appear to be rare in the marketplace, double-ended or bifitted incandescent electric light bulbs are known in the art. Generally such bulbs include two diametrically opposed bases, each provided with a respective single electrical terminal for each glowing resistor. Whereas such bulbs may be connected in plurality, base-to-base in series with or without the use of separable intervening bulb-to-bulb connectors, such bulbs cannot be connected in a circuit in parallel to one another without the use of sockets wired in parallel with one another in an electrical circuit which is disposed externally of the light bulbs.
SUMMARY OF THE INVENTION
An incandescent electric light bulb is provided with two fittings, typically two opposed screw-threaded bases, each with two terminals. The bulb is provided with internal parallel conductors between corresponding terminals of the two fittings. One or more incandescent filaments is or are connected between the conductors within the bulb. Accordingly, several of the bulbs may be connected fitting-to-fitting, electrically in parallel, with or without inter-bulb connectors, with no need for externally wired sockets between adjoining bulbs. Various fittings, connectors and supports are described.
The principles of the invention will be further discussed with reference to the drawings wherein preferred embodiments are shown. The specifics illustrated in the drawings are intended to exemplify, rather than limit, aspects of the invention as defined in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings
FIG. 1 is a somewhat schematic longitudinal sectional view of a first embodiment of the bifitted incandescent electric light bulb with internal electrically parallel conductors;
FIG. 2 is a schematic view of an electrical circuit incorporating several of the bulbs of FIG. 1, and exemplary bulb-to-bulb connectors and fitting terminators;
FIGS. 3, 4, 5, 6 and 7 are respective somewhat schematic longitudinal sectional views of the bulb-to-bulb connectors and fitting terminators shown in FIG. 2;
FIG. 8 is a somewhat schematic fragmentary side elevational view showing a portion of the installation depicted in FIG. 2, further including two different forms of mechanical suspension hangers for the installation;
FIG. 9 is a somewhat schematic longitudinal sectional view of a second embodiment of the bulb;
FIG. 10 is a schematic view of an electrical circuit incorporating several of the bulbs of FIG. 9;
FIG. 11 is a somewhat schematic longitudinal sectional view of a fitting terminator shown in FIG. 10; and
FIG. 12 is a somewhat schematic longitudinal sectional view of a third embodiment of the bulb.
DETAILED DESCRIPTION
In FIG. 1, a bifitted incandescent electric light bulb 10 according to a first embodiment of the invention is shown by itself. In the instance of this embodiment the glass envelope 12 is externally provided at two spaced apart (e.g. diametrically opposed) locations, with a respective two fittings 14, 16. In the instance depicted in FIG. 1, each of these fittings 14, 16 is identical to the other, and, for instance is like or similar to the conventional base for screw-into-socket type incandescent electric light bulbs. That is, each base is provided in the form of an external, generally cylindrical boss 18 where the sidewall is provided by a screw-threaded tubular collar 20 of electrically conductive material, e.g. brass and the outer end wall is provided by a center terminal boss 22 surrounded by a sealing annulus 24 of dielectric material.
Within the bulb envelope, a first electrical conductor 26 interconnects the two peripheral terminals 20 and a second electrical conductor 28 interconnects the two center terminals 22.
Because the fittings 14 and 16 are identical, the bulb 10 cannot be directly screwed together with another bulb 10 to provide a multibulb unit 30 that is mechanically connected in series whereas its individual bulbs are electrically connected in parallel. However, this may be simply accomplished with the use of interbulb connectors which are shown in FIG. 2. (In FIGS. 3-7 the different types of interbulb connectors 32, 34, 36 and 38 and the fitting terminator 40 all rudimentarily depicted in FIG. 2 are individually illustrated in somewhat greater detail.)
In the instance of each of the elements 32-38, a structural body 42, e.g. of electrically insulating material is provided with a plurality of fitting-receivers 44 which are spaced from one another on the body. Each fitting receiver 44 is shown provided to be in the nature of a respective socket having an internally threaded tubular, electrically conductive sidewall terminal 46, an inner end wall boss-like center terminal 48 of electrically conductive material, with an inner end wall annular mechanically bridging portion 50 of electrically insulating material. Within the body 42, respective isolated conductors 52, 54 electrically connect respective terminals 46, 48.
The illustrated bulb-connectors 32-38 differ from one another as to detail. For instance, the bulb connector 32 of FIG. 3 is straight and has a rigid body with two oppositely axially opening sockets; the bulb connector 34 of FIG. 4 is similar, but has a flexible intermediate body portion 56; the bulb connector 36 of FIG. 5 has a rigid body with two sockets set at an angle, e.g. at a right angle to one another in order to incorporate a corresponding degree of turn to the string of bulbs 10 incorporating that connector; and the bulb connector 38 of FIG. 6 includes a rigid body with three sockets set in a Y-pattern. These connectors are merely illustrative, since other patterns may be provided using the same principles.
The end or fitting terminator 40 shown in FIG. 7 is similar, except that it has but one socket, in which the peripheral terminal 46 is electrically connected to the center terminal 48 by a relatively low resistance conductor 58.
Mechanical hangers may be provided as illustrated in FIG. 8 where two types are shown at 60, 62. The hanger 60 may be constituted by one or more tensile rods or straps for connection between one of the connectors 32-38 and the ceiling, or the like 64. The other hanger 62 may be constituted by an elongated flexible strap 66, e.g. of fiber-reinforced flexible plastic material with a loop 68 integrally provided at each end each loop 68 is slipped over one end of a connector 32-38 or a terminator 40 and, e.g. seated in complementary, intermediately located notches 70. At the center of the arch thus formed, the hanger 62 may be hooked to the ceiling or the like 64.
A second embodiment of the bulb is illustrated at 110 in FIG. 9. This embodiment is like the one shown in FIG. 1, except that one of the cylindrical boss-type fittings 114 is replaced by a complementary socket-type fitting 116. Accordingly, except to execute corners, Y's and the like the bulbs 110 may be simply screwed together boss-to-socket, without the need for intervening connectors (FIG. 10). Where connectors are needed, e.g. to execute corners and Y's they may correspond to those shown in FIGS. 3-7, with some socket-type fittings of connectors replaced by complementary boss-type fittings.
Likewise a fitting terminator 140 may be provided (FIG. 11) for terminating the socket-fitted end of a bulb 110. It is like the fitting 40 used for boss-fitted ends, except that its conductor 158 extends between the center and peripheral terminals of a complementary boss-type fitting.
A third embodiment of the bulb is shown at 210 in FIG. 12. Here, all that is different from the embodiment shown in FIG. 9 is that the screw-threaded boss-type and socket-type fittings are respectively replaced by corresponding lateral pin boss-type and J-slot socket-type fittings 214, 216.
The bifitted bulbs, connectors and fitting terminators shown in FIGS. 1-12 are illustrative of these and other types of mechanical and electrical elements and members which may be provided to make use of the principles of the invention.
It should now be apparent that the bi-fitted incandescent electric light bulbs with internal electrically parallel conductors as described hereinabove, possesses each of the attributes set forth in the specification under the heading "Summary of the Invention" hereinbefore. Because it can be modified to some extent without departing from the principles thereof as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the spirit and scope of the following claims. | An incandescent electric light bulb is provided with two fittings, typically two opposed screw-threaded bases, each with two terminals. The bulb is provided with internal parallel conductors between corresponding terminals of the two fittings. One or more incandescent filaments is or are connected between the conductors within the bulb. Accordingly several of the bulbs may be connected fitting-to-fitting, electrically in parallel, with or without inter-bulb connectors, with no need for externally wired sockets between adjoining bulbs. Various fittings, connectors and supports are described. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to excavating machinery and, more particularly, to tractor-mounted backhoe apparatus principally including an articulated boom mounted pivotally at one end to the rear of a tractor and a digging or trenching bucket carried by the boom at its free end. It is common in such backhoe apparatus that the articulated boom is comprised of a main arm or mast and a second arm, frequently referred to as a dipper stick, to which the digging bucket is pivotally attached. Thus, the main arm is fulcrumed at one end to a tractor mounting and at its free end supports the second arm of the boom through a horizontal pivot. The bucket, in turn, is mounted to swing, via a further horizontal pivot, at the free end of the second arm (dipper stick). In such arrangement vertical movement of the bucket is commonly accomplished through the use of hydraulic drives (cylinders and piston-type drive rods). A first cylinder and rod drive combination acts between the fulcrumed-end of the main arm and a pivot on the upper end of the second arm to swing the latter toward and away from the tractor. A second cylinder and rod drive combination is fastened at one end to the upper portion of the second arm and at the other end to the bucket to rock or curl the bucket about the horizontal pivot connecting the bucket to the second arm.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a unique pivoted secondary arm or dipper stick assembly for incorporation in conventional backhoe excavating apparatus to enable the usual digging bucket to accomplish trenching and excavating operations including sloping trench walls and/or inclined excavations.
A more detailed object of the invention is to accomplish the foregoing through the provision of novel means associated with the dipper stick arm of backhoe excavating apparatus for extending and retracting such arm and for rotating the arm (and the digging bucket pivotally depending therefrom) over as much as 150° from vertical in a clockwise direction and over as much as 150° from vertical in a counterclockwise direction. Thus, the usual digging bucket (with vertical side panels) can be pivoted from its normal vertical orientation to cut, during trenching and excavating operations, sloping trench walls or inclined excavations.
These and other objects and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the backhoe excavating apparatus, embodying the features of the present invention, mounted on the rear of a tractor, showing the novel rotatable and extendable dipper stick portion of the boom and attached digging bucket in raised position;
FIG. 2 is a top view, partly in cut-away section, of the novel dipper stick portion of the backhoe boom showing the internal mechanisms for extending and rotating same;
FIG. 3 is a front view, partly in cut-away section, of the dipper stick of FIG. 2;
FIG. 4 is a section view of the dipper stick of FIG. 2 and FIG. 3 taken along line 4--4 of FIG. 3 showing the hydraulic rotator assembly of the dipper stick; and
FIG. 5 is a section view of the dipper stick of FIG. 2 and FIG. 3 taken along line 5--5 of FIG. 3 showing the connection assembly between the dipper stick and the hydraulic rotator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings for purpose of illustration, the present invention is embodied in tractor-mounted backhoe excavating apparatus 10 such as is designed to perform various types of excavation work including trench digging. As shown in FIG. 1 the backhoe apparatus 10 is mounted on the back of a tractor 11 by appropriate attachment to a platform 12. The details of the tractor itself are not important to this invention other than that the platform 12 may provide side-to-side rotatable support to the backhoe apparatus (with respect to the tractor) about a vertical pivot incorporated in the platform. The entire backhoe apparatus 10 may be articulated as a unit with respect to the platform, by appropriate horizontal pivotal support (not shown) incorporated in the platform and a hydraulic actuator (also not shown) extending between the platform and the lower part of the platform attachment end of the backhoe apparatus.
The tractor-mounted backhoe excavating apparatus 10 is basically comprised of: an elongated arm or mast 13 fulcrumed at its platform-mounting end on the vertical pivotal support of the platform and having a horizontal pivot 14 at its free end for pivotally supporting a second arm 15 (commonly called a dipper stick); and a digging bucket 16 mounted to swing at the outer end of the dipper stick about the generally horizontal pivot 17. With the foregoing arrangement vertical movement of bucket 16 may be accomplished through the use of hydraulic operating mechanisms including cylinders 18 and 19 and their respective reciprocating drive rods 20 and 21. The hydraulic cylinder 18 and drive rod 20 act between the platform-mounting end of arm 13, where the cylinder is attached to parallel cylinder mounts 22 (affixed to such arm) via horizontal pivot 23, and a pivot 24 on the pivot end of the dipper stick 15 to swing the latter over nearly a 180° arc toward and away from the tractor 11. The hydraulic cylinder 19 is fastened to parallel cylinder mounts 25 (mounted on the upper portion of the dipper stick 15) via horizontal pivot 26 and its drive rod 21 is connected via horizontal pivot 27, parallel link bars 28, pivot 29 and parallel bars 30 to digging bucket 16 to rock or curl the bucket (over nearly a 240° arc) about its pivot 17. The rocking or curling rotational motion of bucket 16 is assured by parallel link bars 31 which are pivoted at one end from the extended end of dipper stick 15 via horizontal pivot 32 and which at the other end provide support for horizontal pivot 27. Additional hydraulic cylinder-type actuators (not shown) may act between the platform 12 and mast or arm 13 to swing the latter upwardly and downwardly and from side-to-side to thereby further position the backhoe excavating apparatus and digging bucket with respect to the tractor and/or the terrain to be excavated or trenched.
The dipper stick portion 15 of the backhoe excavating apparatus 10 of the present invention includes additional features not heretofore incorporated in such devices. Thus, the dipper stick of the invention is extendable and rotatable providing significant additional versatility and maneuverability of the apparatus during excavating and trenching operation thereof. Extendability of the dipper stick arm 15 is accomplished through telescoping members 33 and 34 forming such arm. Rotatability of dipper stick arm 15 (and thereby digging bucket 16) is accomplished through hydraulic rotator assembly 35 incorporated into such arm at its pivot end. The hydraulic rotator assembly 35 is mechanically affixed to arm member 33 (as described in detail hereinafter with respect to FIGS. 2, 3 and 5) and to parallel dipper stick pivot plates 36 which, with dipper stick 15, rotate about horizontal pivot 14 at the free end of main arm or mast 13. The parallel pivot plates 36 connect with drive rod 20 of hydraulic cylinder 18 through horizontal pivot 24.
Referring now particularly to FIGS. 2 thru 5 the second arm or dipper stick 15 of the invention is shown to comprise principally of hollow telescoping members 33 and 34. In the preferred embodiment member 33 is square in cross-section and telescopes within member 34 of larger square cross-sectional configuration. Members 33 and 34 are maintained in telescoping alignment and sliding relationship by two sets of bearing or bushing plates 37 and 38. As illustrated, each bearing plate set includes four plates with plates 37 being affixed to the extended end of member 33 on its outer surfaces for bearing contact with the inner surfaces of member 34. Plates 38 are removably affixed to the inner surfaces of member 34 (at its end nearest the hydraulic rotator assembly) for bearing contact with the outer surfaces of member 33. These bearing plates are L-shaped in cross-section, as shown in FIG. 2, and are individually inserted between the corresponding sides of dipper stick members 33 and 34 after such members have been assembled by sliding the extended end of member 33 (with plates 37) into and through a substantial portion of member 34. The L-shaped bearing plates are thereafter inserted between members 33 and 34 with the leg portion 39 of each such plate being affixed to member 34 via bolts 40 clamping the leg portions 39 of each bearing plate to a matching locking plate 41 affixed to and carried by the outer surface of member 34.
Extension and retraction of dipper stick 15 through extended and retracted telescoping of members 33 and 34 is accomplished and controlled by internally housed hydraulic actuator 42 comprised of double-wall hydraulic cylinder 43 and its associated piston driven rod 44. The hydraulic actuator 42 extends centrally through rotator assembly 35 and terminates in end plate 45 which is affixed to an end plate of the rotator assembly. Actuator 42 is connected at its drive rod end to pivot 46 which extends laterally between the side walls of member 34 near its free end whereat bucket 16 is pivotally supported. Extension of dipper stick 15 via hydraulic actuator 42 is accomplished by introducing hydraulic fluid to the space 47 within cylinder 43 between end plate 45 and piston 49 (at the driven end of rod 44) through a fluid line 50 while withdrawing hydraulic fluid from the space 48 within cylinder 43 between cylinder cap 43a and piston 49 through ports 43b in the inner wall 43c of cylinder 43, the annular space between inner wall 43c and outer wall 43d of cylinder 43, and fluid line 51 thus forcing rod 44 to be extended without cylinder 43 and thereby driving dipper stick member 34 away from the pivot plates 36. Retraction of dipper stick 15 is accomplished by withdrawing hydraulic fluid from space 47 through fluid line 50 while introducing hydraulic fluid to space 48 via fluid line 51 thus drawing piston 49 (and rod 44) toward end plate 45 and thereby pulling dipper stick member 34 toward the pivot plates 36.
Rotation of dipper stick arm 15, as mentioned heretofore, is accomplished through hydraulic rotator assembly 35 incorporated into such arm at its pivot end. The rotator assembly is principally comprised of an annular housing 52, cylindrical rotator element 53 positioned internally of the housing, and rotator housing end plates 54a and 54b. The housing 52 and rotator element 53 together form an annular space 55. Housing 52 bears an internal hydraulic fluid dam 56 which extends radially throughout the length of space 55 toward and to the rotator element. The cylindrical rotator element 53 bears a wing portion 57 which extends radially throughout the length of space 55 toward and to the inner wall 58 of housing 52. By particular reference to FIG. 4 it will be seen that rotator element 53, shown in its normal position, may rotate within housing 52 over approximately 150° clockwise and 150° counterclockwise from such normal position.
The rotatable position of rotator element 53 within housing 52 is established by introducing and withdrawing hydraulic fluid from space 55 on either side of wing portion 57 forming, with fluid dam 56, sub-spaces 55a and 55b. Thus, hydraulic fluid may be introduced to sub-space 55a through a fluid line 59 and withdrawn from sub-space 55b through a fluid line 60 to move and position wing portion 57 clockwise of its normally vertical position. By introducing hydraulic fluid through line 60 to sub-space 55b while withdrawing such fluid from sub-space 55a through line 59 wing portion 57 is moved and positioned counterclockwise within annular space 55.
Rotator element 53 of the hydraulic rotator assembly 35 may be attached to dipper stick member 33 in the manner illustrated in FIG. 5. Thus, an adequate dipper stick support portion of rotator element 53 extends into dipper stick member 33 with the space between such element and such member filled by transition piece or adaptor block 61. Member 33 of the dipper stick is fastened to rotator element 53 (for rotation therewith) via fasteners 62 extending through member 33, transition piece 61 and into the rotator element 53 itself. Additional locking of rotator element 53 to transition piece 61 may be accomplished by one or more key members 63 extending between such element and the transition piece.
As previously mentioned the hydraulic rotator assembly 35 is mechanically affixed to parallel dipper stick pivot plates 36. It is further supported at the pivot end of the dipper stick arm by horizontal plate 64 which extends under the rotator assembly between pivot plates 36, and by parallel vertical plates 65a and 65b which enclose the ends of such assembly (including housing end plates 54a and 54b) and likewise extend between pivot plates 36. Additional reinforcing members and plates may be added to the assembly of parts and devices comprising the pivot end of the dipper stick arm to provide the structural strength necessary to withstand the lifting and rotating forces applied to the arm during excavating maneuvers.
It is obvious that appropriate end seals must be applied to the hydraulic rotator assembly 35 via end plates 54a and 54b to contain the hydraulic fluid within such assembly and that the tolerances between rotator wing portion 57 and inner wall 58 of annular housing 52, and between fluid dam 56 of the housing and the rotator 53, must be such that rotation of the rotator can be effected but seepage of hydraulic fluid between sub-spaces 55a and 55b is inhibited. Likewise, all hydraulic actuators utilized in connection with the articulation movements of mast 13, dipper stick 15 and bucket 16, and the extension of the dipper stick, must be provided with appropriate hydraulic fluid seal means with respect to their cylinders and piston driven actuator rods so that positive and controlable movements of the components of the entire backhoe structure of the invention can be carried out.
In operation of the tractor and backhoe excavating apparatus, the tractor is first set and supported by a pair of legs 66 (FIG. 1) which are mounted on the rear of the tractor adjacent opposite sides of platform 12. Each of the legs includes a hydraulic cylinder 67 with one end connected to the tractor and a rod 68 extending out of the other end. Pivotally attached to the free end of each of the rods is a foot pad 69 for distributing the weight of the tractor across a relatively large area of ground. By adjusting the extent of projection of the rods 68 from the cylinders, the rear of the tractor may be leveled and supported by the legs for digging with the digging bucket 16.
Once the tractor is in position and set for excavating, first entry into the ground is accomplished by actuating the cylinders 18 and 19 to retract rods 20 and 21 and thereby straighten out and fully extend the backhoe excavating apparatus 10. At the same time, the actuator (not shown in FIG. 1) for controlling vertical movement of the main mast or arm 13 is actuated to pivot the mast toward the ground until the digging teeth 16a of bucket 16 strike the ground. Thereafter, the bucket 16 is curled on the end of the dipper stick 15 while the dipper stick is pivoted toward the tractor (by extension of rod 20 from cylinder 18) while the mast 13 is pivoted away from the ground to cause a load of earth to be scooped into the bucket. Repeated scooping forms the desired excavation or trench which may be widened simply by swinging the mast 13 horizontally to one side or the other and scooping alongside the previously scooped areas. One of the important advantages of the present invention relates to the extendability and retractability of the dipper stick arm. Thus, in apparatus of the general type disclosed herein, if the main mast 13 can not be raised or lowered to pivot same toward or away from the ground, essentially the same scooping action as described heretofore can be accomplished by extending the dipper stick arm to its full length at the commencement of the scooping stroke and retracting such arm as it is pivoted toward the tractor.
Digging or trenching in the above described fashions with the usual digging bucket having vertical or upright side panels (as shown in FIG. 1) results in the formation of an excavation or trench with substantially vertical side walls. Such excavations may be satisfactory for some purposes but in other instances sloping walls may be required. Through the present invention sloping trench walls or inclined excavations may be formed by a conventional digging bucket through the use of the hydraulic rotator assembly 35 provided at the pivot end of the dipper stick arm 15. Thus, actuation of such hydraulic assembly results in rotation and positioning of the dipper stick and bucket by as much as 150° clockwise and 150° counterclockwise of vertical.
The present invention is not limited to the details of the structure disclosed and described herein, but is intended to cover all substitutions, modifications and equivalents within the scope of the following claims. | In a backhoe type of excavating apparatus comprised principally of: a main arm or mast fulcrumed at one end from a rear platform of a tractor; a second hydraulically articulated arm, or so-called dipper stick, supported by and pivoted on the free end of the main arm; and a trenching or digging bucket pivotally attached to the free end of the dipper stick and being hydraulically articulated to provide a swinging or curling motion thereto, an improved dipper stick constructed of telescoping sections for extending or shortening the length thereof in response to an internally contained hydraulic actuator and including at its mast supported end a hydraulic rotator assembly whereby the dipper stick (and attached digging bucket) may be rotated over approximately 150° in each direction from its normal vertical orientation. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2007/051368, filed Feb. 13, 2007 and claims the benefit thereof, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to the welded repair of defects lying on the inside of components.
BACKGROUND OF THE INVENTION
[0003] Components are tested in various ways after production or after use, sometimes then finding defects lying on the inside that often have to be repaired.
[0004] According to the prior art, material is removed from the crack not only if the crack occurs on the surface but also if it is lying on the inside, i.e. does not go through to the outer surface. Such cracks from which material is removed are then closed by being brazed or welded. This removal of material is time-consuming, since it represents a further working step. In particular, it must be ensured that all the material is removed from the crack.
SUMMARY OF THE INVENTION
[0005] It is therefore the object of the invention to provide a method that simplifies the welded repair of defects lying on the inside.
[0006] The object is achieved by a method for the welded repair of defects lying on the inside according to the claims.
[0007] This method uses a flux which is applied to the surface of the component near the crack and is then welded.
[0008] Further advantageous measures, which can be combined with one another as desired to achieve further advantages, are listed in the dependant claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention is described in detail with reference to the drawings, in which:
[0010] FIGS. 1 , 2 and 3 show the procedure involved in the method,
[0011] FIG. 4 shows a gas turbine,
[0012] FIG. 5 shows a perspective view of a turbine blade,
[0013] FIG. 6 shows a perspective view of a combustion chamber and
[0014] FIG. 7 shows a list of superalloys.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 shows a component 1 , 120 , 130 , 155 , which has in the substrate 7 a crack 4 that does not extend as far as the outer surface 10 , that is to say is completely enclosed in the substrate 7 of the component 1 , 120 , 130 , 155 .
[0016] In particular in the case of turbine components, the material of the substrate 7 is preferably a nickel- or cobalt-based alloy. Examples of nickel- or cobalt-based alloys that are used can be found in FIG. 7 . Similarly, the method can be used for steels (for stainless high-grade steels, e.g. SS410) and for parts of a compressor or for guiding grooves.
[0017] An arrangement for repairing the crack 4 as shown in FIG. 1 is schematically shown in FIG. 2 . Cracks 4 lying on the inside are detected, preferably by means of an eddy current method 5 .
[0018] Then an “active” flux 13 , known from the prior art, is applied to the surface 10 in the region above the crack 4 . The flux 13 is preferably in the form of a powder. The flux 13 preferably consists of powder.
[0019] The flux 13 may preferably also be applied by being brushed or sprayed on as a suspension, or as an alcohol- or water-based slurry, with or without a binder. Similarly preferably, the powder may be in a pressed form, that is to say as a strip or sheet. Fine-grained powder (+1 μm/−45 μm) is preferably used for the filler.
[0020] For welding, fusion welding methods and/or plasma welding methods are preferably used:
manual arc welding metal arc welding with a flux-cored wire electrode and no shielding gas; submerged-arc welding with a wire electrode, submerged-arc welding with a flux-cored wire electrode, metal inert gas welding (MIG welding), metal active gas welding (MAG welding), tungsten inert gas welding (TIG welding), gas welding with an oxyacetylene flame.
[0029] TIG welding is used with preference. Similarly, other methods such as laser welding or electron-beam welding may also be used.
[0030] By means of a welding device 16 (TIG welding device, laser welding device, etc.), which produces a plasma 19 or emits laser beams 19 , the flux 13 is melted and the region around the crack 4 is completely encompassed, with the result that around the crack 4 there forms a melting zone 22 , which may be up to 8 mm deep (=depth of the molten pool), as shown in FIG. 3 . A person skilled in the art can set laser parameters (duration, intensity, power, . . . ) material-specifically and component-specifically, in order to encompass a crack 4 completely in a melting zone 22 .
[0031] In FIG. 3 , the melting zone does not extend through the entire thickness of the component 7 . Similarly, particularly in the case of hollow or thin-walled components, the melting zone 22 may preferably extend over the entire thickness. Further welding is not necessary. The worked location is preferably also reworked.
[0032] A flux from the prior art may be chosen for the flux 13 . The flux 13 is preferably a powder. Similarly preferably, the flux 13 may be a powder mixture. A composition of SiO 2 or Fe 2 O 3 may preferably be used. Similarly preferably, a composition of titanium oxide (0-60% by weight), nickel oxide (0-40% by weight) and magnesium silicide (0-10% by weight) can be used.
[0033] The combinations:
titanium oxide nickel oxide manganese silicide titanium oxide/nickel oxide titanium oxide/manganese silicide nickel oxide/manganese silicide titanium oxide/nickel oxide/manganese silicide are respectively preferred exemplary embodiments.
[0042] The much improved depth of the molten pool when cracks are laser welded and remelted with such an “active” flux 13 or surface-active suspensions, as they are known, is influenced by the following factors:
[0043] a: Marangoni effect: the energy and heat transfer during the welding/remelting takes place by movement of liquid metal in the molten pool. If the movements on the surface of the molten pool are outwardly directed, the molten pool becomes wide and shallow. An inwardly directed movement makes the molten pool become narrow and deep. The kind of movement in the molten pool is influenced by the surface tension of the liquid metal. By deliberately adding surface-active substances (filler), it is possible to change the surface tension in the molten pool in such a way that the movement of the liquid metal is inwardly directed, and consequently a much improved depth of the molten pool is achieved.
[0044] b: Improved absorption of the welding beam: the surface-active substance is remelted in the course of the welding process and forms a very thin layer (slag) on the surface of the molten pool. This thin layer not only influences the surface tension of the molten pool but also at the same time has much improved properties in terms of absorption of the welding beam in comparison with the liquid metal of the base material. It is consequently possible to produce an improved energy transfer and depth of the molten pool, which under certain circumstances can reach up to 4-8 mm.
[0045] The improved energy transfer in the case of TIG welding/remelting with surface-active substances is achieved by an enrichment of the arc with electrons. This enrichment has the effect of constricting the arc, and consequently producing a much higher energy density and improved depth of the molten pool.
[0046] FIG. 4 shows by way of example a gas turbine 100 in a longitudinal partial section.
[0047] The gas turbine 100 has in the interior a rotor 103 with a shaft 101 , which is rotatably mounted about an axis of rotation 102 and is also referred to as a turbine runner. Following one another along the rotor 103 are an intake housing 104 , a compressor 105 , a combustion chamber 110 , for example of a toroidal form, in particular an annular combustion chamber, with a number of coaxially arranged burners 107 , a turbine 108 and the exhaust housing 109 .
[0048] The annular combustion chamber 110 communicates with a hot gas duct 111 , for example of an annular form. There, the turbine 108 is formed for example by four successive turbine stages 112 .
[0049] Each turbine stage 112 is formed for example by two blade rings. As seen in the direction of flow of a working medium 113 , a row of stationary blades 115 is followed in the hot gas duct 111 by a row 125 formed by moving blades 120 .
[0050] The stationary blades 130 are in this case fastened to an inner housing 138 of a stator 143 , whereas the moving blades 120 of a row 125 are attached to the rotor 103 , for example by means of a turbine disk 133 . Coupled to the rotor 103 is a generator or a machine (not presented).
[0051] During the operation of the gas turbine 100 , air 135 is sucked in by the compressor 105 through the intake housing 104 and compressed. The compressed air provided at the end of the compressor 105 on the turbine side is passed to the burners 107 and mixed there with a fuel. The mixture is then burned in the combustion chamber 110 to form the working medium 113 . From there, the working medium 113 flows along the hot gas duct 111 past the stationary blades 130 and the moving blades 120 . At the moving blades 120 , the working medium 113 expands, transferring momentum, so that the moving blades 120 drive the rotor 103 and the latter drives the machine coupled to it.
[0052] The components that are exposed to the hot working medium 113 are subjected to thermal loads during the operation of the gas turbine 100 . The stationary blades 130 and moving blades 120 of the first turbine stage 112 , as seen in the direction of flow of the working medium 113 , are thermally loaded the most, along with the heat shielding elements lining the annular combustion chamber 110 .
[0053] In order to withstand the temperatures prevailing there, these may be cooled by means of a coolant. Similarly, substrates of the components may have a directional structure, i.e. they are monocrystalline (SX structure) or only have longitudinally directed grains (DS structure).
[0054] Iron-, nickel- or cobalt-based superalloys are used for example as the material for the components, in particular for the turbine blade 120 , 130 and components of the combustion chamber 110 .
[0055] Such superalloys are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; these documents constitute part of the disclosure with respect to the chemical composition of the alloys.
[0056] The stationary blade 130 has a stationary blade root (not represented here), facing the inner housing 138 of the turbine 108 , and a stationary blade head, at the opposite end from the stationary blade root. The stationary blade head faces the rotor 103 and is fixed to a fastening ring 140 of the stator 143 .
[0057] FIG. 5 shows in a perspective view a moving blade 120 or stationary blade 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0058] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0059] The blade 120 , 130 has, following one after the other along the longitudinal axis 121 , a fastening region 400 , an adjoining blade platform 403 and also a blade airfoil 406 and a blade tip 415 .
[0060] As a stationary blade 130 , the blade 130 may have a further platform at its blade tip 415 (not represented).
[0061] In the fastening region 400 there is formed a blade root 183 , which serves for the fastening of the moving blade 120 to a shaft or a disk (not represented).
[0062] The blade root 183 is designed for example as a hammer head. Other designs as a firtree or dovetail root are possible.
[0063] The blade 120 , 130 has for a medium which flows past the blade airfoil 406 a leading edge 409 and a trailing edge 412 .
[0064] In the case of conventional blades 120 , 130 , solid metallic materials, in particular superalloys, are used for example in all the regions 400 , 403 , 406 of the blade 120 , 130 .
[0065] Such superalloys are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; these documents constitute part of the disclosure with respect to the chemical composition of the alloy.
[0066] The blade 120 , 130 may in this case be produced by a casting method, also by means of directional solidification, by a forging method, by a milling method or combinations of these.
[0067] Workpieces with a monocrystalline structure or structures are used as components for machines which are exposed to high mechanical, thermal and/or chemical loads during operation. The production of monocrystalline workpieces of this type takes place for example by directional solidification from the melt. This involves casting methods in which the liquid metallic alloy solidifies to form the monocrystalline structure, i.e. to form the monocrystalline workpiece, or in a directional manner. Dentritic crystals are thereby oriented along the thermal flow and form either a columnar grain structure (i.e. grains which extend over the entire length of the workpiece and are commonly referred to here as directionally solidified) or a monocrystalline structure, i.e. the entire workpiece comprises a single crystal. In these methods, the transition to globulitic (polycrystalline) solidification must be avoided, since undirected growth necessarily causes the formation of transversal and longitudinal grain boundaries, which nullify the good properties of the directionally solidified or monocrystalline component.
[0068] While reference is being made generally to solidified structures, this is intended to mean both monocrystals, which have no grain boundaries or at most small-angle grain boundaries, and columnar crystal structures, which indeed have grain boundaries extending in the longitudinal direction but no transversal grain boundaries. These second-mentioned crystalline structures are also referred to as directionally solidified structures.
[0069] Such methods are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1; these documents constitute part of the disclosure with respect to the solidification method.
[0070] Similarly, the blades 120 , 130 may have coatings against corrosion or oxidation (MCrAlX; M is at least one element of the group comprising iron (Fe), cobalt (Co) and nickel (Ni), X is an active element and represents yttrium (Y) and/or silicon and/or at least one element of the rare earths, or hafnium (HD). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1, which are intended to constitute part of this disclosure with respect to the chemical composition of the alloy.
[0071] The density is preferably 95% of the theoretical density. A protective aluminum oxide layer (TGO=thermal grown oxide layer) forms on the MCrAlX layer (as an intermediate layer or as the outermost layer).
[0072] The composition of the layer preferably comprises Co-30Ni-28Cr-8Al-0.6Y-0.7Si or Co-28Ni-24Cr-10Al-0.6Y. Apart from these cobalt-based protective coatings, nickel-based protective coatings are also preferably used, such as Ni-10Cr-12Al-0.6Y-3Re or Ni-12Co-21Cr-11Al-0.4Y-2Re or Ni-25Co-17Cr-10Al-0.4Y-1.5Re.
[0073] A thermal barrier coating which is preferably the outermost layer and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. is unstabilized, partially stabilized or completely stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, may also be present on the MCrAlX.
[0074] The thermal barrier coating covers the entire MCrAlX layer. Columnar grains are produced in the thermal barrier coating by suitable coating methods, such as for example electron-beam physical vapor deposition (EB-PVD).
[0075] Other coating methods are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have grains which are porous, are provided with microcracks or are provided with macrocracks for better thermal shock resistance. The thermal barrier coating is therefore preferably more porous than the MCrAlX layer.
[0076] The blade 120 , 130 may be hollow or be of a solid form. If the blade 120 , 130 is to be cooled, it is hollow and may also have film cooling holes 418 (indicated by dashed lines).
[0077] FIG. 6 shows a combustion chamber 110 of the gas turbine 100 . The combustion chamber 110 is designed for example as what is known as an annular combustion chamber, in which a multiplicity of burners 107 , which produce flames 156 and are arranged in the circumferential direction around an axis of rotation 102 , open out into a common combustion chamber space 154 . For this purpose, the combustion chamber 110 is designed as a whole as an annular structure, which is positioned around the axis of rotation 102 .
[0078] To achieve a comparatively high efficiency, the combustion chamber 110 is designed for a comparatively high temperature of the working medium M of approximately 1000° C. to 1600° C. To permit a comparatively long operating time even with these operating parameters that are unfavorable for the materials, the combustion chamber wall 153 is provided on its side facing the working medium M with an inner lining formed by heat shielding elements 155 .
[0079] On account of the high temperatures in the interior of the combustion chamber 110 , a cooling system may also be provided for the heat shielding elements 155 or for their holding elements. The heat shielding elements 155 are for example hollow and, if need be, also have cooling holes (not represented) opening out into the combustion chamber space 154 .
[0080] Each heat shielding element 155 of an alloy is provided on the working medium side with a particularly heat-resistant protective layer (MCrAlX layer and/or ceramic coating) or is produced from material that is resistant to high temperature (solid ceramic bricks).
[0081] These protective layers may be similar to the turbine blades, meaning for example MCrAlX: M is at least one element of the group comprising iron (Fe), cobalt (Co) and nickel (Ni), X is an active element and represents yttrium (Y) and/or silicon and/or at least one element of the rare earths, or hafnium (Hf). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1, which are intended to constitute part of this disclosure with respect to the chemical composition of the alloy.
[0082] A thermal barrier coating which is for example a ceramic thermal barrier coating and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. is unstabilized, partially stabilized or completely stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, may also be present on the MCrAlX.
[0083] Columnar grains are produced in the thermal barrier coating by suitable coating methods, such as for example electron-beam physical vapor deposition (EB-PVD).
[0084] Other coating methods are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have grains which are porous, are provided with microcracks or are provided with macrocracks for better thermal shock resistance.
[0085] Refurbishment means that turbine blades 120 , 130 and heat shielding elements 155 may have to be freed of protective layers after use (for example by sandblasting). This is followed by removal of the corrosion and/or oxidation layers or products. If need be, cracks in the turbine blade 120 , 130 or the heat shielding element 155 are then also repaired. This is followed by recoating of the turbine blades 120 , 130 or heat shielding elements 155 and renewed use of the turbine blades 120 , 130 or the heat shielding elements 155 . | The repair of cracks according to the state of the art comprises the fact that defects located on the inside must be worked outward in order to be able to be welded closed. The method according to the invention proposes not to work out cracks located on the inside, but to melt the crack located on the inside utilizing a flux agent. | 1 |
The present invention claims priority from French Patent Application No. 0104582, filed Apr. 4, 2001.
The invention relates to a new cosmetic and/or therapeutic film former composition for a topical use, the invention also relates to the use of this film former composition for the delivery of active ingredients to the skin. More particularly, the present invention relates to film forming compositions, containing 1 to 50 wt % polyurethane, preferably polyurethane-1; at least 0.01 wt %, but less than 2.0 wt %, cellulose and 0.05 to 5.0 wt % magnesium aluminum silicate; wherein the film forming composition forms a uniform mist when discharged from a spray bottle or pump sprayer. The present invention also relates to a method for applying a film forming composition to an individual's skin by spraying the film forming composition onto the skin, wherein the film forming composition contains 1 to 50wt % polyurethane, preferably polyurethane-1; at least 0.01 wt %, but less than 2.0 wt %, cellulose and 0.05 to 5.0 wt % magnesium aluminum silicate; and wherein the film forming composition forms a uniform mist when sprayed. The present invention also relates to a method for treating a dermatological disease by applying to the skin of an individual a film forming composition of the invention containing an active agent for such treatment.
Conventional cosmetic or therapeutic compositions permit the application of active agents to the skin. However, an application at skin level must resist environmental conditions and clothes friction. Conventional compositions exhibit poor resistance to such environmental conditions and must be reapplied frequently to achieve the desired purpose (cosmetic or therapeutic). For example, in cosmetology, the use of cellulose and clay to suspend particles is conventionally practiced. The films resulting from these conventional compositions, however, are often easily removed with a combination of friction and water. Moreover, these films tend to be very dry and powdery.
Applicant's have developed a film forming composition for topical use which solves the above-mentioned problems with the conventional compositions. The film forming compositions of the present invention, when applied to the skin, dry to a smooth, uniform and distinctive film, which may be visible or invisible depending on the specific application, which is comfortable to wear and which resists environmental conditions such as rain and slight friction.
The film forming compositions of the present invention provide a method for delivering active agents to the skin of an individual. Particularly, the film forming compositions of the present invention provide improved contact times and for controlled release.
SUMMARY OF THE INVENTION
In a preferred embodiment of the present invention, film forming compositions are provided, containing: 1 to 50 wt % polyurethane, preferably polyurethane-1; at least 0.01 wt %, but less than 2.0 wt %, cellulose and 0.05 to 5.0 wt % magnesium aluminum silicate. In a preferred aspect of the invention, the film forming composition forms a uniform mist when discharged from a spray bottle or pump sprayer.
In a preferred aspect of the present invention, the cellulose contained in the film forming compositions is hydroxypropyl methylcellulose.
In another preferred aspect of the present invention, the film forming compositions further contain an active agent, more preferably 0.01 to 10 wt % active agent. Preferably, the active agent is selected from the group of a therapeutic agent, a cosmetic agent and mixtures thereof. The active agent may also preferably be selected from the group of a hydrophilic ingredient, a lipophilic ingredient and mixtures thereof. More preferably, the active agent may be selected from the group of alpha-hydroxy acids, beta-hydroxy acids, alpha-hydroxy acid derivatives, beta-hydroxy acid derivatives, botanical extracts, botanical extract derivatives, vitamins, vitamin salts, vitamin esters, vitamin alcohols, acid forms of salts, marine products, marine product derivatives, hormones and enzymes.
In another preferred aspect of the present invention, the film forming compositions further contain an ingredient selected from the group of hydrophilic solvents, lipophilic solvents, humectants/plastisizers, thickening polymers, dyes, colorants, surfactants/emulsifiers, fragrances, preservatives, chelating agents, UV absorbers/filters, antioxidants, keratolytic agents, dihydroxyacetone and penetration enhancers; wherein the thickening polymers are in addition to the polyurethane and the cellulose. Preferably, the film forming compositions of the present invention may contain 5 to 90 wt % hydrophilic solvents. Preferably, the film forming compositions of the present invention may contain 1 to 10 wt % lipophilic solvent. Preferably, the film forming compositions of the present invention may contain 0.5 to 20 wt % humectants/plastisizers. Preferably, the film forming compositions of the present invention may contain 0.1 to 10 wt % thickening polymers. Preferably, the film forming compositions of the present invention may contain 0.1 to 10 wt % surfactants/emulsifiers. Preferably, the film forming compositions of the present invention may contain 0.01 to 12 wt % pigments, dyes and colorants. Preferably, the film forming compositions of the present invention may contain 0.1 to 5 wt % fragrances. Preferably, the film forming compositions of the present invention may contain 0.01 to 3 wt % preservatives. Preferably, the film forming compositions of the present invention may contain 0.01 to 1 wt % chelating agent. Preferably, the film forming compositions of the present invention may contain 0.01 to 10 wt % UV absorbers/filters. Preferably, the film forming compositions of the present invention may contain 0.05 to 3wt % antioxidants.
In another preferred embodiment, the film forming compositions of the present invention may preferably be formulated for topical use as a liquid, a semi-solid lotion or a semi-solid gel. Most preferably this composition will either be a spray, a lotion, a gel, a roll-on or a mousse.
In another preferred embodiment of the present invention, a method of applying a film on an individual's skin is provided, which method includes: (1) spraying a film forming composition onto the skin, wherein the film forming composition contains 1 to 50 wt % polyurethane, preferably polyurethane-1; at least 0.01 wt %, but less than 2.0 wt %, cellulose and 0.05 to 5.0 wt % magnesium aluminum silicate; and wherein the film forming composition forms a uniform mist when sprayed. In a preferred aspect of this embodiment of the present invention, the method further includes: allowing the film forming composition to dry on the skin and wearing the dry film for 20 minutes to several hours, more preferably 20 minutes to four hours. In another preferred aspect of this embodiment, the film forming composition further contains an active agent for treatment of a dermatological disease, preferably a dermatological disease selected from the group of acne, psoriasis and eczema.
In another preferred embodiment of the present invention, a method of applying and fixing pigments, dyes or colorants onto the skin is provided, which method includes: spraying a film forming composition onto the skin, wherein the film forming composition contains 1 to 50 wt % polyurethane, preferably polyurethane-1; at least 0.01 wt %, but less than 2.0 wt % cellulose; 0.05 to 5.0 wt % magnesium aluminum silicate and 0.01 to 12 wt % pigments, dyes and/or colorants; wherein the film forming composition forms a uniform mist when sprayed. In a preferred aspect of this embodiment of the present invention, the method further includes: allowing the film forming composition to dry on the skin and wearing the dry film for 20 minutes to several hours, more preferably 20 minutes to eight hours, most preferably 20 minutes to several hours.
DETAILED DESCRIPTION
The present invention provides a film forming composition for topical use which includes a polymeric system containing polyurethane, cellulose and magnesium aluminum silicate.
Polyurethane suitable for use with the invention includes copolymers of isophtalic acid, adipic acid, hexylene glycol, neopentylene glycol, dimethylolpropanic acid and isophoronic diisocyanate monomers. Most preferably, the polyurethane used with the invention includes polyurethane-1.
The film forming compositions of the present invention exhibit the capacity to release active agents to the skin level. Applicants have discovered that magnesium aluminum silicate, polyurethane and cellulose form a synergistic combination. Used individually, each of magnesium aluminum silicate, polyurethane and cellulose tend to dry and flake. When combined in the film forming compositions of the present invention, these components provide a unique formula which exhibits increased stability.
Moreover, cellulose based compounds are generally not suited for spray application from a spray bottle or pump sprayer. The polymer combination of the present invention, however, provides a composition which is suited for spray application. Specifically, the polymer combination of the present invention provides a composition which forms a uniform mist when sprayed.
The film forming compositions of the present invention preferably contain:
from 1 to 50% by weight polyurethane, more preferably from 3 to 30%,
from 0.01 to 2.0% by weight cellulose, more preferably from 0.01 to 1.0%,
from 0.05 to 5.0% by weight magnesium aluminum silicate, more preferably from 0.1 to 3.0%.
When the polyurethane content is below 3%, the resulting film forming compositions do not form a sufficiently distinctive film. When the cellulose content is above 1.0%, the resulting film forming composition begins to exhibit unfavorable spraying characteristics and the resultant film tends to be both weak and breakable. When the magnesium aluminum silicate content is below 0.1%, the efficiency of the suspending effect of particles deminishes. When the magnesium aluminum silicate content is above 3.0%, the resultant film becomes brittle.
Cellulose suitable for use with the present invention includes any kind of cellulose, such as hydroxypropyl methylcellulose or hydroxyethyl cellulose. Preferably, the cellulose contained in the film forming compositions of the present invention is hydroxypropyl methylcellulose.
The film forming compositions of the present invention preferably provide a system for the delivery of an active agent at the skin level. Consequently, preferable film forming compositions of the present invention contain an active agent, more preferably 0.01 to 10% by weight of an active agent. Preferably, the active agent is selected from the group of therapeutic agents, cosmetic agents and mixtures thereof. The active agents may include natural or synthetic, hydrophilic agents or lipophilic agents.
Active agents suitable for use with the present invention include: alpha-hydroxy acids; alpha-hydroxy acid derivatives; beta-hydroxy acids; beta-hydroxy acid derivatives; botanical extracts; botanical extract derivatives; vitamins such as vitamins C, B, E, K or A or the salts, esters, alcohols or acid forms thereof; marine products; marine product derivatives; hormones and enzymes.
The film forming compositions of the present invention may further optionally contain additional components including: hydrophilic solvents, lipophilic solvents, humectants/plastisizers, thickening polymers others than cellulose and polyurethane, dyes, colorants, surfactants/emulsifiers, fragrances, preservatives, chelating agents, UV absorbers/filters, antioxydants, keratolytic agents, dihydroxyacetone and penetration enhancers.
The film forming compositions of the present invention may preferably contain 5 to 90% by weight hydrophilic solvents. Hydrophilic solvents suitable for use with the present invention include any solvent conventionally used in cosmetology or in dermatology. Preferred hydrophilic solvents suitable for use with the present invention include: water; alcohols (for example, ethanol, glycols and mixtures thereof).
The film forming compositions of the present invention may preferably contain 1 to 10% by weight lipophilic solvents. Lipophilic solvents suitable for use with the present invention include solvents such as hydrocarbons and oils. Preferred lipophilic solvents suitable for use with the present invention include: iso-paraffin, mineral oils, isododecane, sweet almond oil and other natural oils.
The film forming compositions of the present invention may preferably contain 0.5 to 20% by weight humectants/plastisizers. Humectants/plastisizers suitable for use with the present invention include any water-binding ingredient conventionally used in cosmetic or dermatological products. Preferred humectants/plastisizers suitable for use with the present invention include glycols (glycerin, propylene glycol, 1,3-butylene glycol and polyethylene glycols), dimethicone copolyol, sorbitol, sodium PCA, and sodium citrate.
The film forming compositions of the present invention may preferably contain 0.1 to 10% by weight thickening polymers other than cellulose and polyurethane. Thickening polymers suitable for use with the present invention include any polymer or thickener conventionally used in cosmetic or dermatological products. Preferred thickening polymers suitable for use with the present invention include xanthan gum; PVA; PVP; carbomer; and mixtures, such as: (a) ammonium polyacrylate, isohexadecane and polyethylene glycol-40 castor oil (an example of such a mixture suitable for use with the present invention is available from Seppic under the trademark Simulgel A); (2) polyacrylamide, polydecene and ethoxylated lauryl alcohol (an example of such a mixture suitable for use with the present invention is available from C. I. T. Sarl under the trademark Ceragel EZ-7); (3) polyacrylamide, C 13-14 isoparaffin and ethoxylated lauryl alcohol (an example of such a mixture suitable for use with the present invention is available from Seppic under the trademark Sepigel 305); and (4) polyquaternium 32 and mineral oil (an example of such a mixture suitable for use with the present invention is available from Ciba under the trademark Salcare SC-92). Thickeners may be added to the compositions of the present invention to modify the viscosity of the composition, the feel of the composition and the film formed therewith when applied to the skin of a subject, the spreadability of the composition and the strength of the film formed by the composition upon application to the skin of a subject.
The film forming compositions of the present invention may preferably contain 0.1 to 10% by weight surfactants/emulsifiers. Surfactants/emulsifiers suitable for use with the present invention include any anionic, cationic or nonionic surfactants or emulsifiers conventionally used in cosmetic or dermatological products. Preferred surfactants/emulsifiers suitable for use with the present invention include ethoxylated alcohols, sodium lauryl sulfate, and polyquaternium-31.
The film forming compositions of the present invention may preferably contain 0.01 to 12% by weight pigments, dyes and colorants. Pigments, dyes and colorants suitable for use with the present invention include any dye or pigment conventionally used in cosmetic, dermatological and food products. Preferred pigments, dyes and colorants suitable for use with the present invention include titanium dioxide; zinc oxides; iron oxide; micas, preferably pearlized micas; and organic lakes.
The film forming compositions of the present invention may preferably contain 0.1 to 5% by weight fragrance. Fragrance suitable for use with the present invention includes any fragrance conventionally used in cosmetic or dermatological products. Fragrance or fragrance mixtures may be incorporated into the film forming compositions of the present invention to, for example, support a marketing concept or to mask the natural odor of the subject composition.
The film forming compositions of the present invention may preferably contain 0.01 to 3% by weight preservative. Preservative suitable for use with the present invention includes any preservative or mixture of preservatives conventionally used in cosmetic or dermatological compositions. Preferred preservatives suitable for use with the present invention include methylparaben, isoporpylparaben, propylparaben, isobutylparaben, butylparaben and phenoxyethanol. Preservatives may preferably be incorporated in the film forming compositions of the present invention to enhance the resistance of said film forming compositions from microbiological contamination.
The film forming compositions of the present invention may preferably contain 0.01 to 1% by weight chelating agents. Chelating agents suitable for use with the present invention include any chelating agent conventionally used in cosmetic or dermatological products. Preferred chelating agents suitable for use with the present invention include ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid-disodium salt and ethylenediaminetetraacetic acid-tetrasodium salt. Chelating agents may preferably be incorporated into the film forming compositions of the present invention to help stabilize those compositions.
The film forming compositions of the present invention may preferably include 0.01 to 10% by weight UV absorbers/filters. UV absorbers/filters suitable for use in the film forming compositions of the present invention include any water and/or oil soluble sunscreen conventionally used in cosmetics. Preferred UV absorbers/filters suitable for use with the present invention include benzophenone-3 and benzophenone-4, titanium dioxide and zinc oxide.
The film forming compositions of the present invention may preferably include 0.05 to 3% by weight antioxidants. Antioxidants suitable for use in the film forming compositions of the present invention include any antioxidants conventionally used in cosmetics. Preferred antioxidants suitable for use with the present invention include tocopherol, tocopherol acetate, propyl gallate, butylated hydroxyanisole and butylated hydroxytoluene. Preferably, the as compositions of the present invention may contain 0.05 to 3 wt % antioxidants.
The film forming compositions of the present invention may preferably be for topical use and may advantageously be liquid or semi-liquid. Most preferably, the film forming compositions of the present invention may be a spray, a lotion, a gel or a roll-on.
Preferably, when a film forming composition of the present invention can be worn on the skin of a subject for a period of 20 minutes to several hours following application thereto as a dry film. Most preferably, the film forming compositions of the present invention may be removed from the skin of a subject by rinsing with water or with a combination of rinsing with water and use of a surfactant.
The present invention also provides a method of using a film forming composition for topical delivery of an active agent for the treatment of a dermatological disease, for example, acne, psoriasis and eczema. The active ingredient used in the cosmetic composition is chosen for its activity in the treatment of these dermatological diseases.
The present invention also provides a method of using a film forming composition of the present invention for topical use in a cosmetic product.
EXAMPLES
The preferred embodiments of the present invention will now be further described through the following examples set forth hereinbelow which are intended to be illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the invention as set forth in the appended claims.
Some preferred formulations for film forming compositions of the present invention are provided in Table 1. The film forming compositions of the present invention noted in Table 1 may be produced as follows: the polymers are blended in one of: water, alcohol or a mixture thereof. A supply of heat may be useful in preparing film forming compositions of the present invention which include clay or a gum. Polymers may be added one after the other with continual mixing until the mixture is smooth. The other ingredients may be added after the uniform polymer mixture is obtained. High sheer may preferably be used to incorporate UV absorbers/filters into the composition.
TABLE 1
Example 1
Example 2
Example 3
Ingredients
A% (wt/wt)
B% (wt/wt)
C% (wt/wt)
Water
QS to 100
QS to 100
QS to 100
Methylcellulose
0.01 to 1.0
0.01 to 1.0
0.01 to 1.0
Mg, Al silicate
0.10 to 3.0
0.10 to 3.0
0.10 to 3.0
Polyurethane
3.0 to 30.0
3.0 to 30.0
3.0 to 30.0
Alcohol
0.1 to 30.0
0.1 to 30.0
Glycol (e.g., butylene,
0.10 to 5.0
0.1 to 5.0
0.1 to 10.0
propylene, hexalene
or glycerin or PEG)
Inorganic UV filters
0.01 to 10.0
(e.g., titanium dioxide
or zinc oxides)
UV Absorbers (e.g.,
1.0 to 8.0
benzophone-3 or 4,
octyl salicylate, octyl
methoxycinnamate)
Preservatives
0.01 to 3.0
0.01 to 3.0
0.01 to 3.0
Active ingredient
0.01 to 3.0
0.01 to 3.0
0.01 to 3.0
Viscosity modifiers
0.01 to 3.0
0.01 to 3.0
0.01 to 3.0
pH adjusters (e.g.,
0.01 to 3.0
0.01 to 3.0
0.01 to 3.0
organic or inorganic
acids, amines or
hydroxides)
Examples 4 and 5
Compositions of the present invention according to the formulas presented in Table 2 may be prepared according to Examples 4 and 5.
TABLE 2
Example 4
Example 5
Ingredients
(% w/w)
(% w/w)
Water
QS
QS
Glycerin
1.0
Biophilic H (Hydrogenated
2.0
Lecthin, C12-16 Alcohols,
Palmitic Acid)
Methocel E4M (HPMC)
0.20
0.20
Veegum HV (Mg Al Silicate)
0.45
0.30
Carbomer
0.15
0.15
AMP
0.20
0.20
Amino-methyl-propanol
Polyurethane
20.0
10.0
Dimethicone Copolyol
0.50
0.50
Preservative
0.70
Mg Ascorbyl Phosphate
0.20
Ethanol SDA 40-2 (190 proof)
9.0
The composition identified in Table 2 as Example 4 may be prepared as follows:
(a) the biophilic (commercially available from Lucas Meyer) is mixed with water under slow stirring at 70° C.;
(b) the glycerin is added to the product of (a) with continual slow stirring until a coarse and fluid dispersion is obtained; care is to be taken during this step to keep the temperature from falling below 50° C.;
(c) the methocel E4M (commercially available from Dow Chemical) is added to the product of (b) with continual mixing until it is completely hydrated;
(d) the Veegum HV (commercially available from R. T. Vandrbilt) is added to the product of (c) with continual mixing until it is completely hydrated;
(e) the carbomer (commercially available from Noveon) is added to the product of (d) with continual mixing until it is completely hydrated;
(f) the AMP (commercially available from Angus) is added to the product of (e) with continual mixing until a smooth uniform product is obtained;
(g) the polyurethane is added to the product of (f) with thorough mixing;
(h) the dimethicone copolyol is added to the product of (g) with thorough mixing; and,
(i) the preservative is added to the product of (h) with thorough mixing.
The composition identified in Table 2 as Example 5 may be prepared as follows:
(a) the methocel E4M is mixed with water until fully hydrated;
(b) the veegum HV is mixed with the product of (a) until fully hydrated;
(c) the carbomer is mixed with the product of (b) until fully hydrated;
(d) the product of (c) is heated to about 50° C.;
(e) the AMP is added to the product of (d) and blended until smooth and uniform;
(f) the Mg Ascorbyl Phosphate is dissolved in water and heated to 40° C.;
(g) the product of (f) is blended with the product of (e);
(h) the polyurethane is added to the product of (g) with continual mixing;
(i) the dimethicone copolyol is added to the product of (h) with continual mixing;
(j) the ethanol CDA 40-2 is added to the product of (i) with continual mixing; and,
(k) the preservative is added to the product of (j) with continual mixing until a uniform product is formed.
Examples 6-9
Table 3, below, provides various exemplary formulations of the film forming compositions of the present invention suitable for topical use as a make-up spray patch. The formulations presented in Table 3 include various amounts of different pigments. The formulations provided in Examples 6 and 8 relate to a film forming compositions of the present invention which contain iron oxides, titanium dioxide and nacreous pigments with dimethicone copolyol and cyclomethicone as the emollient/humectant system. The formulations provided in Examples 7 and 9 relate to a film forming compositions of the present invention which contain titanium dioxide, iron oxides, nacreous pigments and glycol as the emollient/humectant system.
TABLE 3
Ex. 6
Ex. 7
Ex. 8
Ex. 9
(%
(%
(%
(%
Ingredient
w/w)
w/w)
w/w)
w/w)
Water
QS
QS
QS
QS
Methocel E4M (HPMC)
0.32
0.20
0.32
0.50
Veegum HV (Mg AL Silicate)
0.90
0.45
0.90
1.20
Carbomer
0.15
0.10
0.15
0.20
AMP (Aminomethyl propanol)
0.20
0.20
0.20
0.30
Polyurethane-1 (30% soln. in
18.00
12.00
18.00
25.00
water and alcohol)
Dimethicone Copolyol and
5.00
—
4.00
—
cyclomethicone
Glycol (Glycerin, Propylene
—
2.00
—
4.00
Glycol, Butylene Glycol)
Biological Extracts
0.70
1.00
0.70
2.00
Preservative
0.70
0.70
0.70
0.80
Titanium Dioxide
2.10
3.50
1.80
4.00
Mica Pearl (Nacreous)
0.20
0.10
1.00
0.50
Iron Oxides
1.70
1.40
1.20
2.50
Example 10
The formulations presented in examples 6-9 may be blended in water. Heat may optionally be provided if, for example, clay or a gum is used. The polymers may be added one after another with agitation until a smooth mixture is obtained using a standard mixer with a sheer selected according to the materials being incorporated. The remaining ingredients may be added to the smooth mixture. High sheer may be required to incorporate iron oxides and titanium dioxide into the composition.
The present invention having been disclosed in connection with the foregoing preferred embodiments and examples, additional embodiments will now be apparent to persons skilled in the art. The present invention is not intended to be limited to the preferred embodiments specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion, to assess the spirit and scope of the present invention in which exclusive rights are claimed. | Cosmetic and/or therapeutic film former compositions for a topical use and for optional delivery of active ingredients to the skin are provided. More particularly, film forming compositions are provided, containing 1 to 50 wt % polyurethane, preferably polyurethane-1; at least 0.01 wt %, but less than 2.0 wt %, cellulose and 0.05 to 5.0 wt % magnesium aluminum silicate; wherein the film forming composition forms a uniform mist when discharged from a spray bottle or pump sprayer. A method for applying a film forming composition to an individual's skin is also provided including spraying the film forming composition onto the skin, wherein the film forming composition contains 1 to 50 wt % polyurethane; at least 0.01 wt %, but less than 2.0 wt %, cellulose and 0.05 to 5.0 wt % magnesium aluminum silicate; and wherein the film forming composition forms a uniform mist when sprayed. | 2 |
TECHNICAL FIELD
[0001] This invention pertains to methods of forming high lap shear strength joints in thin sheet metal components, one or more of which may be a magnesium alloy, using fiber-reinforced thermoplastic or thermosetting fasteners in cooperation with mechanically-interfering structures formed by deforming the sheets.
BACKGROUND OF THE INVENTION
[0002] The increasing application of high strength-to-weight-ratio materials is one of several strategies adopted in pursuit of increased automobile fuel economy, and current automobiles incorporate a wide variety of such materials including high strength steel, high performance aluminum alloys and magnesium alloys. Among this variety of higher strength-to-weight-ratio materials, magnesium and its alloys are attractive, due to the low density of magnesium coupled with their ability to achieve acceptably high strength when suitably processed.
[0003] Magnesium is the most chemically active of the commonly-used automotive structural metals and, unless protected, will tend to corrode when exposed to aqueous solutions, particularly when the aqueous solutions are in contact with other metals or contain metallic ions. Treatments and processes to minimize these corrosion tendencies of automotive magnesium alloys have been developed, but in the attachment of magnesium alloys to dissimilar metals, a galvanic cell may be established in the presence of an aqueous electrolyte. In such a cell, the magnesium component will be anodic and preferentially corrode.
[0004] Such a cell may be established when mechanical fasteners such as rivets, bolts or screws are used. These fasteners are almost universally fabricated from another metal or alloy—most commonly steel or, less frequently, aluminum—and are in intimate contact with the magnesium. Hence, any attachment of, or to, a thin wall or sheet magnesium component by mechanical fasteners which penetrate into or through the magnesium article, may create a path for ingress of electrolyte and foster localized corrosion in the vicinity of the fastener. Such corrosion may occur even if the magnesium article is coated with a barrier coating to inhibit overall corrosion, or even if one magnesium alloy article is joined to another magnesium article.
[0005] Thus there is a need for improved methods and fasteners for joining magnesium alloy articles, particularly thin or sheet articles, to other sheet materials, including other magnesium-based alloys.
SUMMARY OF THE INVENTION
[0006] Polymer fasteners may be used to enable a lap joint in two or more overlapping thin workpieces, particularly sheet metal workpieces, at least one of which is a magnesium alloy containing more than 85% magnesium by weight. Such fasteners do not create a potential for galvanic corrosion between the fastener and magnesium. But the lap-shear strength of lap joints, formed in generally planar workpieces is primarily dependent on the fastener strength, and unreinforced polymers, in dimensions similar to those of metal fasteners, may not offer sufficient strength.
[0007] It is a goal of the invention to promote high lap shear strength joints. Two approaches, which are preferably applied in combination, may be followed. The first employs fiber-reinforced polymer fasteners in preference to unreinforced polymer fasteners; the second approach requires deforming the workpieces so that they mechanically engage one another.
[0008] Polymer fasteners comprising polymers reinforced with fibrous reinforcements may be prepared by upsetting the ends of rod-like bodies or slugs formed by extrusion or pultrusion and cut to suitable length. Most often the cross-section of a body will be circular but bodies of other cross-section may be employed without limitation. The fibrous reinforcements may be continuous fibers or as aligned, chopped fibers oriented generally coaxial with the axis of the body and uniformly or non-uniformly distributed within the body cross-section.
[0009] The polymer matrix of such a fastener may be a thermoplastic, so that it may be readily shaped at a temperature greater than its glass transition temperature, while retaining maximum strength at ambient temperature, or about 25° C. Suitable matrices may include relatively low performance thermoplastics like polyamide or polypropylene, but in structures which experience the automotive paint bake cycle (160-200° C. for at least 20 minutes), high performance thermoplastics with a relatively high glass transition or crystallization temperature, such as polyphthalamide, polyphenylene sulfide, polyamide-imide, polyether sulphone and polyarylene ketone, among others, are preferred.
[0010] Thermosetting polymers (thermosets) may also be employed. Thermosets may offer superior creep resistance and dimensional stability to thermoplastics and may be preferred for applications involving higher temperature exposure. Preferably these will be B-staged epoxies or a cross-linkable thermoset below its T g . B-staged epoxies are those in which only limited reaction between the resin and hardener has taken place so that the product is in a semi-cured, highly-viscous, but deformable state. Deformation may be facilitated at mildly elevated temperatures. Depending on their formulation the partial cure of such B-staged epoxies may occur at room temperature, about 25° C., or at more elevated temperatures. Higher curing temperature thermosets are preferred. Suitable examples include: epoxy resins, such as diglycidyl ether of bisphenol-A-based resin (such as Hexion Epon 828) or novalac-based resin (such as Hexion Epon SU-2.5) cured with an amine, anhydride, or imidazole curing agent; unsaturated polyester resins, such as those based on propylene glycol cured with a peroxide and, optionally, thickened with magnesium oxide; and a vinyl ester resin (such as Ashland Derakane) cured with a peroxide and, optionally, thickened with magnesium oxide. Thus the fastener formed of such a thermoset may be heated to develop full strength in the thermoset. This may be done using heat lamps or by passing the assembled components through an oven. Alternatively curing may be promoted by exposure to ultraviolet light or to an electron beam.
[0011] Suitable fiber reinforcements may include glass and aramid fibers. Carbon fibers may also be suitable provided they can be assuredly isolated from the magnesium. Mixed fibers may also be used, and fibers may be braided or otherwise grouped or associated, or incorporated in the matrix as individual fibers. For example, carbon fibers may be positioned in the interior of a braided aramid or glass fiber sleeve to assure isolation of the carbon fibers. Fibers may be generally uniformly distributed across the body cross-section or may be positioned selectively, for example to provide selective reinforcement or to facilitate upsetting with minimal fiber damage, or, as in the case of carbon fibers, to locate them out of possible contact with the workpiece(s). Natural fibers, such as bast fibers, including hemp and jute may also be used.
[0012] Such fasteners may preferably be formed-in-place by inserting short rod-like lengths or bodies of the fiber-reinforced polymer in a hole commonly formed in the workpiece stack formed by the overlapping sheets. The hole may be created by drilling or piercing. Piercing may be facilitated by heating at least the magnesium sheet(s) to about 250° C. to enhance its ductility. The diameter of fiber-reinforced polymer, which may be heated to greater than ambient temperature, should be sized for ready entry to the hole while affording minimal clearance between it and the body. The body may be chamfered for ease of insertion.
[0013] After insertion in the hole, the body may be advanced until it extends, preferably by about an equivalent amount on either side of the stack, from the top and bottom surfaces of the stack. The lengths of the extending portions should preferably range from about 1.2 to 2 times the hole diameter. Hence, the length of the body should preferably substantially equal the thickness of the workpiece stack plus a distance equal to between 2.4 and 4 times the hole diameter for a generally cylindrical body. The protruding portions of the body may then be upset, to form, on each side of the stack, a head whose size exceeds that of the hole to secure the members of the stack together. The upsetting may be done simultaneously so that approximately equal and opposing loads are applied to each end of the body, or the upsetting may be performed sequentially, provided suitable provision is made for application of a reaction force opposing the upsetting force.
[0014] For thermoplastics the body is preferably preheated to a temperature at least greater than the glass transition temperature of the thermoplastic prior to insertion into the hole. For an amorphous polymer, temperatures only slightly above the glass transition temperature may be suitable, while polymers with more crystalline character may require temperatures approaching the melting temperature. Preheating of the entire body will facilitate upsetting and promote deformation in the portion of the body surrounded by the workpieces during upsetting. Thermosets may be inserted and deformed at room temperature but curing will commonly require heating of at least the fastener, for example, using heat lamps or passing the assembly through a furnace or heater. In some applications curing may be conducted in a paint cure oven employing a temperature between about 160° C. and 200° C. or with ultraviolet or electron beam curing.
[0015] The head formed by the upsetting operation should extend appreciably beyond the edges of the sheet opening to effectively deny access of water or aqueous salts to the clean metal surface exposed by the hole-making process. The head may be shaped into a simple form, such as a disc or dome, or more complex head geometries may be employed if they better assure continuity of the reinforcing fibers in passing from the shank to the head.
[0016] It is preferred that the body diameter, if cylindrical, be sized to between 85% and 95% of the hole diameter to enable easy insertion of the body and to promote more or less uniform compression, rather than buckling, of the portion of the body surrounded by the workpiece stack during upsetting. Under load, a generally uniformly compressed body will expand laterally and spread outward. Thus, the body portion positioned in the workpiece stack opening will expand to tightly engage the clean metal hole edges and again deny electrolyte access. The greater the initial diameter of the body the less the deformation required to fill the hole, and so, larger body dimensions of between 93% and 95% are more preferred, If more precise body positioning may be achieved, and/or if the body can sustain a larger insertion force, yet larger bodies of up to 99% of the hole diameter may be employed to develop a near-interference fit and minimize the need for any expansion of the body portion in the hole opening It may also be preferred to apply a barrier coating, for example a conversion coating, to the sheet opening after forming the hole.
[0017] Yet further enhancement of joint strength may be achieved by combining upsetting of the ends of the body with selective, cooperative deformation of the workpieces in the stack.
[0018] In a first embodiment, two or more sheets, at least one of which is a magnesium alloy containing more than 85% by weight of magnesium, may be assembled with generally co-planar overlapping regions. At least a portion of the overlapped region may be deformed to provide, in the sheets, mating protuberant features extending out of the plane of the sheets and will resist their being pulled apart when loaded in the plane of the sheet. To enhance the ductility of the magnesium alloy sheet the deformation may be carried out at a temperature of greater than about 250° C. Heating of the sheet to this temperature may be accomplished by electric resistance heating or any other convenient method, such as electric induction heating, frictional heating or laser heating. If the mating protuberances are pierced and joined together with a polymeric body as just described, then the workpiece protuberances will be pulled into close engagement. The engaging protuberances will mechanically interfere, generating mutual support and promoting increased lap-shear joint strength.
[0019] The protuberances may be of any convenient shape and size but flat-bottomed geometries which enable simpler body upsetting, are preferred.
[0020] In a second embodiment, a hole, drilled or pierced, is first made in a stack of overlapping workpieces, at least one of which is a magnesium alloy. The hole is then flanged, preferably at a temperature of greater than about 250° C. to enhance the ductility of the magnesium alloy sheet. Flanging may be carried out by supporting one side of the workpiece stack with an annular die centered on the hole and driving a cylindrical form tool into the hole from the other side of the workpiece stack. The cylindrical form tool may have a tapered end sized to enter the hole. The annular die may be sized with an opening substantially equal to the diameter of the cylindrical tool plus twice the thickness of the stack. When the form tool is fully inserted, each of the workpiece layers surrounding the hole has been bent through 90° and formed into a vertical flange. Each vertical flange tightly engages the flanges formed in the adjacent workpieces to create a series of nested, interlocking flanges.
[0021] In both the first and second embodiments, the joint is completed by insertion of a fiber-reinforced polymer body, upset and suitably dimensioned to exclude electrolytes as described previously. When such a joint is tested, the nested flanges may interfere with one another and contribute significant strength to the joint which will be additive to the contribution of the fastener. The contribution of the nested flanges may be greatest when the joint is tested in lap shear.
[0022] Form tools of other, more complex cross-section, in conjunction with a supporting die of complementary geometry, may be used to create other than a flange of circular outline. For example to restrain relative rotation of the sheets in the plane of the sheets, an oval, triangular or rectangular outline might be employed. It may be preferred to deform the sheets in the stack at elevated temperature, greater than 250° C., to enhance the ductility of the magnesium alloy sheet.
[0023] In a third embodiment, the nested flange geometry of the second embodiment may be deformed further by bending it through a further 90° bend to form the flange through a total bend of 180° so that it is bent back on itself. In this configuration, the lower sheets of the stack are trapped between the underside of the upper sheet(s) and the bent-over, flange portion of the upper sheet(s).
[0024] The flange may be bent in a predictable and consistent manner, preferably using a 2-piece tool. The first piece supports and guides a second piece which advances to engage the flange edges on a doubly-curved die surface and, with further advance progressively splays the edges outward to roll and bend them into the desired 180° bend. Again, it may be preferred to enhance the ductility of at least the magnesium alloy sheet by heating the nested flange region to at least 250° C. The joint may be completed by insertion of a fiber-reinforced polymer body upset and suitably dimensioned to exclude electrolytes as described previously.
[0025] When such a joint is tested, the folded flanges may interfere with one another and contribute significant strength to the joint, additive to the contribution of the reinforced polymer fastener. As with the second embodiment a major enhancement in lap shear strength may be expected. But, because of the more complex deformation, this joint may be expected to display enhanced strength under a wider range of applied load conditions including tension and peel.
[0026] In an aspect of the third embodiment the hole-forming tool may form a hole with one or more radially-extending slots extending to the bend line of the flange to separate the flange into a series of arc segments. In a second aspect of the third embodiment the flange-engaging tool may incorporate cutting edges to separate the flange into a series of arc segments. The arc segments of these aspects may be capable of deforming independently to minimize the hoop strain in the flange.
[0027] The practices and processes may be applied to other metal and polymer workpieces secured by polymer or metal fasteners to promote cooperative interaction between the workpieces and the fastener and thereby develop stronger joints.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows a section through a punch and die suitable for forming nested protuberances on a plurality of overlapping metal sheets.
[0029] FIG. 2 shows a section through the protuberance of FIG. 1 schematically illustrating upper and lower upsetting tools of a first design positioned to upset a fiber-reinforced polymer body inserted in a hole fabricated in the protuberance.
[0030] FIG. 3 shows the same section of the joint as shown in FIG. 2 after the ends of the body have been upset to form the joint.
[0031] FIG. 4 shows section through two overlapping metal sheets with an opening into which a tapered punch has been partially inserted. The sheets are supported on a die centered on the punch and the opening in the sheets.
[0032] FIG. 5 shows, in sectional view, the configuration of the overlapping metal sheets at the conclusion of the punch stroke and illustrates the formation of a plurality of continuous, nested flanges.
[0033] FIG. 6 shows the metal sheet configuration of FIG. 5 after insertion and upsetting of a fiber reinforced polymer body.
[0034] FIG. 7 , shows, in cross-section, the further deformation of the nested flanges of FIG. 5 to form a plurality of nested, rolled-over flanges.
[0035] FIG. 8 shows, in plan view, an aspect of the opening geometry formed in the sheets of FIG. 4 .
[0036] FIG. 9 shows, in plan view, a second aspect of the opening geometry shown in FIG. 4 .
[0037] FIG. 10 shows upsetting of a fiber-reinforced polymer body placed within the hole formed in the overlapping sheets with the rolled-over nested flanges using upsetting tools of a second design.
[0038] FIG. 11 shows the formed fiber-reinforced polymer body produced by upsetting with the upsetting tools shown in FIG. 8 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0039] The corrodible nature of magnesium and its alloys requires the use of special practices to prevent or inhibit corrosion in magnesium-containing structures. This is particularly important where the magnesium alloy is in electrical contact with another metal in the presence of an aqueous solution. For example, in an application like a motor vehicle door, the lower section of the door, will be exposed to road spray, which may contain de-icing salt or other chemicals.
[0040] For at least some applications, the magnesium may be coated or separated from the less corrodible metal by some inert barrier. However, at the point of attachment of the magnesium alloy to the less corrodible metal, direct metal to metal contact will occur. In fact, since a preferred means of attaching magnesium alloys is through the use of mechanical fasteners such as screws, bolts and rivets, among others, even these fasteners may promote galvanic corrosion, since such fasteners are typically fabricated of steel or aluminum. Hence, even in the case where one magnesium alloy is to be attached to another magnesium alloy, the use of mechanical fasteners may require special consideration.
[0041] One approach to inhibiting magnesium alloy corrosion due to fasteners is to employ non-corrodible polymer fasteners which may be fiber-reinforced for enhanced strength. For thin magnesium articles, particularly magnesium sheet articles, a preferred attachment device is a fiber reinforced polymer body, inserted into mating holes in a stack of workpieces and upset on each end to form a head or like structure whose underside is in contact with the abutting workpiece surface.
[0042] The undersides of each of the heads then clamp the stack together. Simultaneously with formation of the head, the portion of the body within the hole, more commonly called a shank, is compressed and expanded to fill the hole. The ends of the body may be upset to form the heads, either substantially simultaneously or sequentially.
[0043] The dimensions of the body should be selected to ensure that the shank does not buckle and that the formed, upset head optimally secures the workpieces. This may be achieved with a body with a shank whose diameter ranges from about 85-95%, more preferably 93-95%, of the hole diameter and which extends beyond the workpiece surface by a distance of between 1.2 and 2 times the hole diameter.
[0044] Since the head is to be formed subsequent to insertion of the body into the hole, it is preferred that the fiber-reinforced polymer body, if it comprises a thermoplastic polymer matrix, be heated to a temperature greater than its glass transition temperature. Suitable thermosets, such as B-staged epoxies may be inserted while at ambient temperatures, as may other crosslinkable thermosets provided they are maintained below their T g or glass transition temperature. Particular examples of suitable B-staged epoxies may include: epoxy resins such as diglycidyl ether of bisphenol-A-based resin cured with an amine or imidazole curing agent; or, polyester or vinyl ester resins cured with a peroxide and, optionally, thickened with magnesium oxide.
[0045] A thermoplastic body may be reliably deformed without cracking or fracturing by heating the body to above its glass transition temperature and deforming it in its plastic state. On cooling to below its glass transition temperature the thermoplastic will regain its higher strength and suitably retain the workpieces in the stack. The thermoplastic may be a relatively low performance thermoplastic like polyamide or polypropylene. But, in applications where the thermoplastic would be exposed to the thermal cycle such as that employed to cure the paint of a vehicle body (typically 160-200° C. for at least 20 minutes), high performance thermoplastics with a relatively high glass transition or crystallization temperature, such as polyphthalamide or polyphenylene sulfide, are preferred, but others, including polyamide-imide, polyether sulphone and polyarylene ketone, may be used.
[0046] Bodies of thermosetting polymers may require an elevated temperature cure so that they may be inserted and upset at room temperature or about 25° C. After insertion and upsetting, at least local application of heat to the fastener will enable polymer cure and develop maximum fastener strength. Such curing may be promoted, for example, by heat lamps, or, possibly, through the use of heated tooling, or by placing the fastener (and assembly) in an oven or furnace, for example a paint bake oven. It will be appreciated that any of curing processes known in the art may be employed, including exposure to ultraviolet radiation or exposure to electron beams.
[0047] The dimensions of the body should be chosen to enhance joint strength while minimizing the size and mass of the body. It may be preferred to reinforce the thermoplastic with fibers, either chopped fibers, or, more preferably continuous fibers. Suitable manufactured fibers may include glass, and aramid fibers. Carbon fibers may also be employed where they would not directly contact any magnesium sheet. Mixed fibers may also be used, and fibers may be incorporated individually or may be assembled into a braided or woven form to enhance cooperative interaction between fibers. Fibers may be generally uniformly distributed across the body cross-section or may be positioned selectively, for example to provide selective reinforcement or to facilitate upsetting with minimal fiber damage. For example, in an aspect of the invention, carbon fibers may be positioned in the interior of a braided aramid or glass fiber sleeve extending along the length of the body to assure isolation of the carbon fibers from the workpieces.
[0048] Natural fibers, for example bast fibers, may also be employed. Bast plants are characterized by long, strong fiber bundles that comprise the outer portion of the stalk and include flax, hemp, kenaf, sunn-hemp, ramie, and jute. Such fibers combine a relatively high tensile strength with a relatively low specific gravity of 0.28-0.62 to yield an especially high specific strength, i.e. strength to weight ratio.
[0049] A fiber-reinforced body may be readily formed using pultrusion or extrusion to form an extended length of fiber-reinforced material and then cutting the extended length to form bodies of appropriate length. Although the body may preferably be circular in cross-section, both pultrusion and extrusion are suitable for preparing bodies of other than circular cross-section, including irregular cross-sections, if preferred.
[0050] FIG. 1 shows, in sectional view, a first embodiment of the invention. A workpiece stack 10 , consisting of partially-overlapping sheet workpieces, 12 and 14 , shown in ghost, supported by die 18 have been indented by flat-bottomed punch 16 . Flat-bottomed punch 16 is centered over the throat, or die opening, 19 of die 18 . As punch 16 is advanced, first into contact with the workpieces and then into die throat opening 19 the workpieces are subjected to deformation out of the plane of the sheet. Typically buckling of the sheets will be inhibited through the use of binder 17 positioned in opposition to die 18 . This out-of-plane deformation of sheets 12 and 14 may form nesting, flat-bottomed, sloping-wall features 20 and 22 in deformed workpiece stack 10 ′ consisting of sheets 12 ′ and 14 ′. Punch 16 and die throat 19 are of complementary cross-section. It will be appreciated that if punch 16 and die throat 19 are circular in cross-section that flat-bottomed, sloping wall features 20 and 22 will have the form of conical cups. However, other punch and throat cross-sections may be adopted as required for, or preferred for, packaging or other reasons.
[0051] At least one of sheets 12 and 14 may be a magnesium alloy. The room temperature formability or ductility of magnesium alloys is generally inferior to that of aluminum alloys and most steels used in automotive bodies. Thus the maximum depth ‘D’ ( FIG. 2 ) of the depression formed in the workpiece stack will generally be limited by the maximum deformation which the magnesium alloy member may sustain without fracture. It is preferred that depth ‘D’ at least equal and preferably exceed twice the sheet thickness. If the room temperature ductility of the magnesium sheet is not sufficient to achieve a specified design depth ‘D’ the ductility of the magnesium alloy sheet may be enhanced by at least locally heating the deformed region to at least 250° C. before forming.
[0052] Such heating may be accomplished by electric resistance heating using separate electrodes, or if the die elements of FIG. 1 may be electrically isolated, by passing an electric current between punch 16 and die 18 . Electrical induction heating may also be used by locating a coil of suitable geometry adjacent to the region to be deformed. Other approaches, such as frictional heating by rotating punch 16 or laser heating by directing laser illumination on the underside of sheet 14 may also be feasible.
[0053] In FIG. 2 , aligned, substantially commonly-sized holes 24 and 26 have been made, for example, by drilling, piercing, laser cutting or other suitable means, in nesting features 20 and 22 . As depicted, holes 24 and 26 have been made after the sheets have been subjected to out-of-plane deformation, but this sequence of steps is not required. Holes 24 and 26 may also be made before the sheets undergo the out of plane deformation. When mechanical processes, such as piercing or drilling are used, the magnesium alloy may first be heated to above 250° C. to minimize edge cracks around the hole.
[0054] A polymer body 28 reinforced by fibers 27 aligned with its long axis has been inserted in the holes. Tooling to upset the body and shaped to impart a generally domed form to the upset head is shown as an upper tool 30 and a lower tool 32 . The body, if a thermoplastic, may be heated to a temperature greater than the glass transition temperature of the thermoplastic. This may be done using, for example, focused radiation like a heat lamp or a laser, or, more simply, by pre-heating the body prior to its insertion in the hole. The body, after reaching the desired temperature may then be promptly upset to form heads 34 and 36 on the end of body 28 ′ as shown in FIG. 3 . For simplicity of illustration the fiber orientation in heads 34 and 36 are represented as paralleling the fiber orientation in body portion 28 ′. It will however be appreciated that the flow of the polymer in heads 34 and 36 will be complex and promote a less regular distribution of fibers in the head portions of the body.
[0055] For convenience and ease of representation, this, and other, embodiments are shown with workpiece stacks consisting of only two workpiece sheets. However, those skilled in the art will appreciate that the practices and processes described may readily be extended to workpiece stacks containing more than two workpiece sheets.
[0056] A second embodiment of the invention is shown in FIG. 4 which shows, in sectional view, a workpiece stack 40 consisting of workpiece sheets 42 and 44 at least one of which is a magnesium alloy. Aligned, substantially commonly-dimensioned openings bounded by cut edges 48 and 46 , have been made in the sheets by one of the previously-described approaches, and workpiece stack 40 has been positioned on die 60 , with openings bounded by cut edges 48 and 46 centrally positioned in die throat 62 .
[0057] Punch 50 , consisting of shank 56 , taper 54 and end 52 , advances along symmetry axis 58 , central to the die throat and substantially perpendicular to the sheet surfaces, in the direction indicated by arrow 62 . End 52 of punch 50 is sized and constructed to pass through the opening as is a portion of tapered punch section 54 . However the relative dimensions of punch, die opening and sheet stack thickness are such that continued advance of punch 50 will cause tapered section 54 to first engage and then downwardly flange the opening edges 46 and 48 . When punch 50 is fully engaged, that is with shank 56 in contact with flange 66 , as shown in FIG. 5 , fully-formed substantially vertical flanges 64 and 66 have been formed in sheets 44 and 42 . Further, flanges 64 and 66 are nested and interfere to restrain lateral motion of deformed sheets 42 ′ and 44 ′.
[0058] Optionally a binder 68 , whose center is coaxial with the center of die 60 may be used to impart pressure on sheets 42 ′ and 44 ′ in the direction of arrow 62 to minimize buckling and poor sheet nesting on the unflanged portion of sheets 42 ′ and 44 ′. The use of binder 68 will be most preferred when the opening bounded by cut edges 46 and 48 are located less than one or two hole diameters from the edges of the sheets.
[0059] Punch 50 , and complementarily-shaped die throat 62 may have circular cross-sections, but cross-sections of other regular and irregular geometries may be used. It will be appreciated that use of a non-circular cross-section punch and die throat will provide resistance to relative rotation of deformed sheets 42 ′ and 44 ′ in addition to restraining lateral motion. Again, due to the limited room temperature ductility of magnesium alloys it may be beneficial to heat the magnesium alloy to a temperature of greater than 250° C. to avoid cracking.
[0060] Analogously to the procedure shown in FIG. 3 , a polymer body 70 , which may be a thermoplastic ( FIG. 6 ), reinforced by fibers 71 , here depicted as chopped discontinuous, fibers oriented parallel to the axis of the body may be inserted into the hole defined by the inner walls 67 of innermost flange 66 , heated and upset using shaped dies to form heads 72 and 74 joined by shank 73 . Preferably, polymer body 70 is so positioned that it extends sufficiently beyond the end of the flange, cut edges 46 , 48 , to provide sufficient material for head 74 to encompass cut edges 46 , 48 . More preferably, as shown in FIG. 6 the flow is sufficiently extensive to fully envelop the flange region and seal against the underside of sheet 44 ′ so that no crevice is created between the fiber-reinforced polymer head and the underside of sheet 44 ′.
[0061] In contrast to FIG. 3 , the pattern of fibers 71 shown in FIG. 6 is more suggestive of the complex flow undergone by the fiber-reinforced polymer body during upsetting. However such depiction is not intended to be representative of any particular fiber distribution which may be achieved.
[0062] A third embodiment is illustrated in FIGS. 7-9 . FIG. 7 illustrates the further deformation of flanges 64 and 66 ( FIG. 5 ) by the shaping surface 82 of form tool 76 which further bends the flanges to bend them back on themselves to form nested, rolled-over, flanges 64 ′ and 66 ′. The end 81 of form tool 76 , when directed as shown by arrow 84 , is sized and constructed to enter the hole formed by inner walls 67 of inner flange 66 ( FIG. 6 ) so that the cut surfaces 46 and 48 contact curved shaping surface 82 of tool 80 . Continued motion of tool 76 will impart a moment to flanges 64 and 66 curling or bending them back on themselves to form rolled-over flanges. Backing plate 75 supports the opposing surface of the workpiece stack, and may, optionally, include features such as protrusion 78 for engagement with cavity 80 of tool 76 for guidance of tool 76 .
[0063] It will be appreciated that the deformation required to form such rolled-over flanges is considerable and that significant strain will be imposed on the workpiece sheets, particularly at the cut surfaces 46 and 48 . It is known that cut edges, like 46 and 48 , may crack under tensile strains lower than those required to initiate cracks in the uncut portions. It is therefore again preferred that at least the magnesium alloy sheet be heated to a temperature of greater than 250° C. to enhance its ductility. Optionally, it may be preferred to flange, as in the process shown at FIG. 5 , slotted opening 47 or segmented opening 49 such as are shown in FIGS. 8 and 9 to reduce the strain at the cut edge and reduce the likelihood of edge cracking.
[0064] As shown in FIG. 8 , the edge 90 of opening 47 comprises a plurality of arcuate segments 92 , here shown, without limitation, as circular arcs, and a plurality of radially-oriented slots 94 terminating at the bend location 96 (shown in ghost) of the flange. The flange will thus be segmented into a series of generally-abutting flange segments, as an example segment 98 , rather than being continuous. In FIG. 9 , the number of arcuate segments 92 ′ forming edge 90 ′ opening 49 is reduced and the extent of the gaps 94 ′, analogous to the ‘slots’ 94 of FIG. 8 is appreciably increased. Thus flanging of segments like 98 ′ by bending along bend line 96 ′ will result in only a few flange segments. However both the configuration of FIG. 8 and of FIG. 9 will produce a series of independent, unattached, flange segments and thereby admit of some relaxation of the flanging strain. The reduction in flanging strain will contribute beneficially to the practices of both embodiment 2 and embodiment 3. Openings 47 and 49 , because of their non-circular shape, will preferably be formed by piercing with a shaped tool. Preferably the magnesium sheet may be heated to about 250° C. to improve its ductility and suppress cracking.
[0065] Consideration of the form of the holes formed after flanging openings 47 and 49 indicates that they will be of irregular form. To ensure that the fiber reinforced polymer body (for example 28 in FIG. 2 ) fully expands to fill the opening it may be desirable to employ an undersized body of complementarily-shaped cross-section, requiring that the body be suitably-oriented to the opening.
[0066] FIG. 10 shows a polymer body 102 , which may be a thermoplastic, reinforced by fibers 103 , inserted in the opening formed by the nested, rolled-over flanges 64 ′ and 66 ′ (shown in FIG. 7 ). It is intended that, after heating the body, if a thermoplastic, to above its glass transition temperature, the ends of the body will be upset using forming tools 106 and 104 . If the matrix of reinforced polymer body 102 is a thermoset which requires an elevated temperature cure, its glass transition temperature will lie above room temperature and such thermosets also will require some heating prior to upsetting. Thermosets which cure at room temperature may be deformed at room temperature.
[0067] Forming tools 104 and 106 differ from forming tools 30 and 32 shown in FIG. 2 in that they incorporate, in addition to the generally domed form of the forming cavity of tools 30 and 32 , a sharp-pointed, tapered, protrusion extending outwards from about the center of the cavity. This variation in shape of tools 104 and 106 is intended to be illustrative and not limiting. A wide range of head tool geometries may be employed to better redistribute the longitudinal fibers 103 of body 102 within the head after upsetting.
[0068] The reinforcing fibers of the body or shank are aligned with the axis of the body. If, as in FIG. 2 , head forming tools 30 and 32 with generally domed recesses are use in upsetting the ends of the body, the flowable polymer matrix will be systematically deformed into a form complementary to the domed recess. The resulting displacements of the reinforcing fibers however will be more arbitrary and will depend on the nature of the fibers, the fiber concentration, the location of particular fibers and whether or not the fibers are woven or braided or otherwise cooperatively associated with other fibers. The geometry of tools 104 and 106 ( FIG. 10 ) seeks to impart a modest outward inclination to the fibers without inducing appreciable fiber fracture so that at least some fibers may remain continuous. Ideally it is preferred that even the outer fibers which overhang the edges of the hole remain generally continuous as schematically illustrated in FIG. 11 in which fibers 103 ′ are continuous from head 108 through shank 102 ′ to opposing head 110 . Again, such representation is intended to be suggestive, rather than representative, of fiber distributions achievable with tools of more complex shape. Although illustrated in conjunction with the practices of the third embodiment, upsetting tools designed for improved control of fiber distribution in the head, including but not limited to the geometry shown, may be applied in all embodiments.
[0069] The configuration of FIG. 11 enables mechanical interference between the workpiece sheets which resists out-of-plane loads such as a tensile load applied along the shank axis of the fastener and cooperatively supports the reinforced thermoplastic fastener in resisting such loads.
[0070] The described practices and processes enable cooperative interaction between the fastener and the workpieces to develop stronger joints. The practices of the invention have been illustrated by disclosure of some preferred embodiments, and particularly to embodiments in which one or more of the workpieces to be joined is (are) magnesium alloy(s). Such illustrative embodiments are not intended to limit the scope of the invention which is applicable to other joints such as when metallic fasteners are employed to join other workpiece stackups or when polymer fasteners are used to join polymer sheets.
[0071] For example, it may be desired to promote a high strength joint in aluminum alloys. Typically aluminum alloys may be deformed at room temperature, or about 25° C. Each of the three described embodiments may be practiced on such an aluminum alloy stack-up by appropriately deforming the sheets of the stack as described. The aluminum sheet stack may then be secured by upsetting a metal or fiber-reinforced polymer body. The body may be an aluminum alloy suitable for deformation at room temperature.
[0072] Similarly, thermoplastic polymer sheets may be heated to above their glass transition temperature and deformed according to the practices of the invention. Such formed polymer sheets may be cooled to room temperature and secured using upset metal or polymer or reinforced polymer bodies as previously described. | A method is disclosed for forming corrosion-resistant joints in a plurality of overlapping thin metal sheet workpieces, at least one of which comprises at least 85% by weight of magnesium sheets. The fastener is a fiber-reinforced polymer rod shaped and sized for insertion into a coaxial opening formed in each sheet and subsequently upset on each end to form a head. The workpiece sheets are deformed to form mechanically-interfering features which cooperatively complement the strength of the fastener, under at least some joint loading patterns. The method may be used for other workpiece and fastener compositions. | 8 |
CLAIM OF PRIORITY
This application claims the benefit of priority under 35 U.S.C. §119 (a) from an application entitled “Optical Network Unit Of Ethernet Passive Optical Network And Control Method Thereof,” filed with the Korean Intellectual Property Office on Aug. 17, 2006 and assigned Ser. No. 2006-77576, the contents of which are incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical network unit of an Ethernet passive optical network and a control method thereof. More particularly, the present invention relates to an optical network unit of an Ethernet Passive Optical Network (EPON) that monitors optical-output control signals in upstream transmission so as to prevent a malfunction thereof in advance. In addition, the present invention relates to an optical network unit of an EPON that prevents influences from being exerted on other optical network units operating normally when an abnormal operation occurs, and a control method of the optical network unit in an EPON.
2. Description of the Related Art
At present, Asymmetric Digital Subscriber Line (ADSL) and cable modem systems are the most widely used for high-speed Internet services. The ADSL system uses existing telephone lines, and provides high-speed Internet services with speeds between 2 Mbps and 10 Mbps through the ADSL modem installed in each subscriber's computer. Users typically install filters on the telephone line immediately prior to entry into a telephone, to filter the noise from ADSL traffic that can adversely affect operation telephones, faxes, etc.
On the other hand, cable modems use existing coaxial cables installed for cable TV services in order to provide high-speed Internet services, so a subscriber must install a cable modem within the area of his/her PC when already subscribing to cable TV service in order to be provided with the high-speed Internet services, or would have to purchase additional equipment, such as a wireless router that receives an output of the cable modem, and install a wireless network card into their pc. Otherwise, coaxial cables output from the modem would have to be run throughout one's house, which is unsightly and labor intensive.
These high-speed Internet services are satisfactory in performance in providing services such as Internet web surfing (HTTP), E-mail, file transfer (FTP), etc. with much higher transmission capacity of 2 to 10 Mbps, as compared with the existing telephone line modem having a speed of 56 Kbps, but they still have a limitation in meeting the users' emerging requirements such as VoIP (Voice over Internet Protocol), VoD (Video on Demand), Internet broadcasting service, etc.
Moreover, high-speed Internet service using the cable modem has a disadvantage in that the bandwidth which can be provided decreases as the number of subscribers increases, and the high-speed Internet service using the ADSL scheme has a disadvantage in that the bandwidth which can be provided decreases as the distance between a telephone office and a subscriber network increases. Also ADSL has problems associated with adverse weather conditions, for example, many subscribers to ADSL are aware that during a thunderstorm it is not unusual for the ADSL connection to be interrupted.
In an attempt to solve these problems, there have been proposed FTTH (Fiber To The Home), FTTB (Fiber To The Building), FTTC (Fiber To The Curb), etc., in which optical cables are installed to the subscriber's in-home network. In addition, studies are being conducted about an Ethernet passive optical network (E-PON) for the sake of enhancing the price-to-service ratio.
More particularly, the E-PON is an Ethernet-associated network which is constructed with passive elements without using power-consuming active elements in the optical subscriber network, so as to enhance its price competitiveness. The standard for the E-PON is being established by the IEEE (Institute of Electrical and Electronics Engineers) 802.3ah Ethernet in the first Mile Task Force. An example of the E-PON is illustrated in FIGS. 1A and 1B and discussed herein below.
FIGS. 1A and 1B are block diagrams illustrating respective flows of upstream and downstream traffic in a conventional E-PON. It can be seen from FIG. 1A that an E-PON has a point-to-multipoint structure in which a plurality of Optical Network Units (ONUs) 20 - 1 to 20 - 3 , etc., are connected to one Optical Line Terminal (OLT) port 10 through a splitter 30 , which is a passive element. Data transference between the OLT 10 and ONUs 20 is performed in units of an Ethernet frame. For example, downstream signals from the OLT 10 to the ONUs 20 are transmitted as broadcasting data, and upstream signals from the ONUs 20 to the OLT 10 share bandwidths allocated to the ONUs 20 by the Time Division Multiple Access (TDMA) scheme.
Therefore, still referring to FIGS. 1A and 1B , upon transmitting upstream signals to the OLT 10 , when the conventional ONUs 20 are granted by the OLT 10 so as to collide between each other in a burst mode scheme, the ONUs 20 will transmit IDLE data (data for clock recovery time and code group arrangement in the OLT) to the OLT 10 , and then transmit corresponding data as upstream frames in the TDMA scheme.
More particularly, each ONU 20 - 1 , 20 - 2 and 20 - 3 transmits frames upstream to the OLT 10 in the TDMA scheme. Each ONU 20 - 1 , 20 - 2 and 20 - 3 is allocated with a time period (time slot) from the OLT 10 , and the individual ONU can transmit a corresponding frame only during the time period (time slot) allocated, as other time slots are allocated to other ONUs, etc. Upon an upstream transmission, when the on/off control of a laser diode is operating in a normal state, the individual ONUs do not transmit outside (beyond) their allocated time slot. However, when the on/off control of the laser is not properly performed due to a malfunction of a particular ONU (such as 20 - 2 ), abnormal data is transmitted in excess of a preset time period.
The extended transmission beyond the respect duration of the time slot by the malfunctioning ONU exerts an influence upon time periods allocated to the other ONUs 20 - 1 and 20 - 3 such that the other ONUs 20 - 1 and 20 - 3 recognize that the malfunctioning ONU 20 - 2 is continuously occupying the transmission line, thereby causing a serious error in data transmitted in the upstream direction.
While ONU # 1 20 - 1 successfully transmits an ONU # 1 data frame during a preset time, that is, during a first time period, ONU # 2 20 - 2 cannot transmit ONU # 2 data within a second time period due to an error occurring in ONU # 2 and occupies the transmission line, even after the second time period has elapsed. That is, ONU # 2 20 - 2 continuously transmits the erroneous ONU # 2 data in excess of a preset time period, so that data collision occurs in a third time period during which the ONU # 3 20 - 3 must be transmitting ONU # 3 data, and such data collision continuously occurs, thereby causing the overall Gigabit E-PON to be unable to transmit data normally. If the malfunctioning ONU# 2 20 - 2 continues to transmit beyond the allocated time slot, the data collisions can slow down or essentially impair the communication capability of the other ONUs that are not malfunctioning.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made in part to solve at least some of the above-mentioned problems occurring in the prior art. The present invention provides an optical network unit and a control method thereof, which monitor optical-output control signals upon an upstream transmission in an Ethernet Passive Optical Network (EPON) so as to prevent malfunction of the optical network unit in advance upon occurrence of an abnormal operation by one of the components, such as an Optical Network Unit (ONU).
Also, the present invention provides an ONU and a control method thereof, which can prevent influences from being exerted on other ONUs operating normally when an abnormal operation occurs in an EPON.
In accordance with an exemplary aspect of the present invention, there is provided an ONU in an E-PON using a time division multiplexing (TDM) scheme, the optical network unit including: a medium access controller for accessing a medium without temporal overlapping. This medium access controller thus functions to transmit during one or more allocated TDM time slots without collision in upstream transmission to an optical line terminal; a burst-mode optical transceiver for converting a signal transferred from the medium access controller into an optical signal having a separately allocated wavelength before outputting the signal in the upstream transmission; and a complex programmable logic device for controlling an optical output of the burst-mode optical transceiver by monitoring an optical-output control signal from the medium access controller.
In accordance with another exemplary aspect of the present invention, there is provided a control method of an ONU in an E-PON using a time division multiplexing (TDM) scheme, the method including the steps of: determining whether there is an optical-output control signal being output in upstream transmission to an optical line terminal, and detecting an output time period of the optical-output control signal; comparing the detected output time period with a preset monitoring time period; determining that the optical-output control signal is abnormal when it is determined that the detected output time period is greater than the monitoring time period as a result of the comparison; and cutting off an optical output of the optical network unit as the optical-output control signal has been determined to be abnormal.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other exemplary aspects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1A is a view illustrating flows of downstream traffic in the conventional system;
FIG. 1B is a view illustrating flows of upstream traffic in the conventional system;
FIG. 2 is a block diagram illustrating the configuration of an optical network unit (ONU) of an Ethernet passive optical network (E-PON) operating under a time division multiplexing scheme according to an exemplary embodiment of the present invention; and
FIG. 3 is a flowchart illustrating exemplary operational steps of the complex programmable logic device according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein may be omitted when it may obscure appreciation of the subject matter of the present invention by a person of ordinary skill in the art. It is understood by an artisan that the drawings and explanation have been provided for explanatory and illustrative purposes and the invention is not limited to the descriptions shown and described.
First, the configuration of an E-PON using the Time Division Multiple Access (TDMA) scheme, to which the present invention is applied, can have a network configuration as shown in the conventional examples in FIGS. 1A and 1B . Accordingly, the description of the E-PON to which the present invention is applied, will continue to refer to the configuration having the OLT 10 , a plurality of ONUs 20 - 1 to 20 - 3 connected with the OLT 10 , and optional connection with a plurality of end users (user network apparatuses) 40 - 1 to 40 - 3 . However, a person of ordinary skill in the art understands and appreciates that the EPON can have a number of different and sometime more complex configurations than shown and the invention is applicable to these other configurations as well.
The pieces of data transmitted by the end users 40 - 1 to 40 - 3 are transferred to the OLT 10 via the ONUs 20 - 1 to 20 - 3 , and the pieces of data transmitted by the OLT 10 are transferred to the end users 40 - 1 to 40 - 3 via the ONUs 20 - 1 to 20 - 3 .
With regard to transmission in a typical E-PON, such data, i.e., Ethernet frames are transmitted at a transmission speed greater than 1 Gbps. Upon an upstream transmission, the OLT 10 accesses data of the ONUs 20 - 1 to 20 - 3 multiplexed in the time division multiplexing (TDM) scheme. Also, upon a downstream transmission, each ONU 20 - 1 to 20 - 3 selects and receives only data which should be received by the ONU, from among data broadcasted by the OLT 10 .
FIG. 2 is a block diagram illustrating an exemplary configuration of an ONU 200 in an E-PON using the TDM scheme according to an exemplary embodiment of the present invention.
Still referring to FIG. 2 , an ONU 200 of an E-PON using the TDM scheme according to an exemplary embodiment of the present invention includes an E-PON medium access controller (E-PON MAC) 100 , a burst-mode optical transceiver 110 , and a complex programmable logic device (CPLD) 120 .
The E-PON MAC 100 has a Time Division Multiple Access Medium Access Control Protocol (TDMA MAC) for accessing a medium without temporal overlapping in order to transmit during one or more allocated TDM time slots without collision in upstream transmission to the OLT 10 .
The burst-mode optical transceiver 110 converts a signal transferred from the E-PON MAC 100 into an optical signal having a separately allocated wavelength before outputting the signal in upstream transmission.
The CPLD 120 monitors optical-output control signals output from the E-PON MAC 100 , and controls an optical output of the burst-mode optical transceiver 110 according to the optical-output control signal.
The CPLD 120 includes a monitoring-interval clock unit 130 , an optical output monitoring unit 140 , a switch unit 150 , a register 160 and a central processing unit (CPU) 170 .
The monitoring-interval clock unit 130 outputs a clock having a monitoring interval preset by a system operator.
The optical output monitoring and control unit 140 measures an elapsed time of a time period from when the output of an optical-output control signal starts from the E-PON MAC 100 , and determines whether a duration of the optical-output control signal is normal or abnormal by comparing the elapsed time with a monitoring time period according to a clock output by the monitoring-interval clock unit 130 . The optical output monitoring unit 140 performs a control function by outputting an optical-output control signal according to a result of the determination to the switch unit 150 .
Still referring to FIG. 2 , the switch unit 150 is turned on/off according to the optical-output control signal being transferred from the optical output monitoring unit 140 so as to control an optical output of the burst-mode optical transceiver 110 . In other words, turning on the switch unit 150 corresponds to continuing the optical output of the burst-mode optical transceiver 110 , and turning off the switch unit 150 corresponds to cutting off the optical output of the burst-mode optical transceiver 110 .
The register 160 stores a status indicating whether a duration of an optical-output control signal is normal or abnormal, which has been determined by the optical output monitoring unit 140 . The register 160 stores normal/abnormal determination signals, which are read under the control of the central processing unit 170 . Note that inventive step involves determining whether the duration of the optical output control signal is abnormal, as opposed to some other measurement regarding the output control signal (phase, intensity, etc) to indicate there is a problem. In other words, so long as the signal has a duration within the allocated timeslot, it is always considered normal.
The central processing unit 170 receives a normal/abnormal determination signal from the optical output monitoring unit 140 , and outputs a control signal for representing a normal/abnormal durational status of the optical-output control signal in accordance with the received normal/abnormal determination signal.
As described above with reference to FIG. 2 , according to an exemplary embodiment of the present invention, the CPLD 120 outputs a clock for determining a monitoring interval. The optical output monitoring unit 140 , which determines whether an optical-output control signal output from the E-PON MAC 100 is normal or abnormal in duration, detects an optical-output control signal at a monitoring interval and stores information regarding whether the detected optical-output control signal is normal or abnormal in the n-bit register 160 . The central processing unit 170 reads what numbered bit of n bits stores an abnormal signal, and then generates a signal informing the OLT 10 that an error has occurred in the optical-output control signal corresponding to the bit storing the abnormal signal. For example, the central processing unit 170 may generate a control signal to flicker a light-emitting diode (LED). Note that the OLT 10 does the CPU 170 in the CPLD of the ONU to inform about the error.
According to an exemplary embodiment of the present invention, an optical-output control signal output from the E-PON MAC 100 is input to the CPLD 120 , and the optical-output control signal is monitored in a predetermined sequence at regular intervals. Thus, when a signal representing an abnormal durational state is defined as “High,” the central processing unit 170 reads what numbered bit is “High” in the n-bit register, and informs the OLT 10 that an error occurs in the optical-output control signal corresponding to the bit defined as “High.”
FIG. 3 is a flowchart illustrating exemplary operational steps of the CPLD 120 according to an exemplary embodiment of the present invention.
In step 301 , the CPLD 120 determines whether there is an optical-output control signal output to the burst-mode optical transceiver 110 , and proceeds to step 303 when there is an optical-output control signal output to the burst-mode optical transceiver 110 . In step 303 , the optical output monitoring unit 140 detects an elapsed time from when the output of the optical-output control signal starts, and proceeds to step 305 .
In step 305 , the optical output monitoring unit 140 compares the duration of an output time period detected in step 303 with a preset monitoring time period. As a result of the comparison, when the detected output time period is greater than the preset monitoring time period, step 307 is performed, and when the detected output time period is smaller than the monitoring time period, step 311 is performed.
In step 307 , it is determined that the optical-output control signal is abnormal because the detected output time period is greater than the monitoring time period, which means that an error may occur in the burst-mode optical transceiver 110 . In step 311 , it is determined that the optical-output control signal is normal because the detected output time period is smaller than the monitoring time period, which means that the optical output of the burst-mode optical transceiver 110 is being properly performed.
In addition, when it is determined that the optical-output control signal is abnormal, the CPLD 120 controls the switch unit 150 to be turned off so as to fully cut off the optical output of the burst-mode optical transceiver 110 in step 309 in order to prevent subsequent data collisions with other ONUs. In contrast, when it is determined that the optical-output control signal is normal, the CPLD 120 controls the switch unit 150 to be in an ON state so that the burst-mode optical transceiver 110 can continue the optical output.
Accordingly, in the E-PON using the TDMA scheme, the ONU 20 monitors an optical-output control signal so as to detect the occurrence of an abnormal operation in upstream transmission, thereby preventing the ONU 20 from causing a malfunction that can impact the network, and preventing the malfunction of the ONU 20 from exerting influences upon other ONUs operating normally.
According to the present invention as described above, an ONU in the E-PON can be prevented from malfunctioning in advance when an abnormal operation occurs by monitoring an optical-output control signal in upstream transmission, and can prevent the malfunction of the ONU from exerting influences upon other ONUs operating normally.
While the present invention has been shown and described with reference to a certain exemplary embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the scope of the invention is not to be limited by the above embodiments but by the claims and the equivalents thereof. For example, while the duration of the output signal is being monitored and controlled by being cut off, there are other features regarding transmission that can be the basis for cutting off an output signal, all of which lie within the spirit of the invention and the scope of the appended claims. The CPLD can be configured for monitoring whether the allocated time slot corresponds to the time the optical-output control signal is on, so if the burst mode transceiver is receiving a signal at an incorrect time slot as compared to the allocated time slot, the control signal can also be cut off. | An optical network unit (ONU) of an Ethernet passive optical network (EPON) and a control method thereof eliminates or substantially reduces instances of an ONU transmitting in time slots other than its allocated time slot. The ONU includes: a medium access controller for accessing a medium without temporal overlapping in order to transmit during one or more allocated TDM time slots without collision in upstream transmission to an optical line terminal; a burst-mode optical transceiver having a separately allocated wavelength before outputting the signal in the upstream transmission; and a complex programmable logic device for controlling an optical output of the burst-mode optical transceiver by monitoring an optical-output control signal from the medium access controller. An erroneous output from an ONU malfunction can be prevented from by cutting off the output once the duration of the allocated time slot has been reached. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor memory device including a plurality of memory cell regions, and more particularly, to improvement of a read/write gate of a semiconductor memory device and a high speed access operation.
2. Description of the Background Art
The semiconductor memory device industry is moving rapidly towards a larger storage capacity and a higher operation speed. This trend is particularly significant in the field of a DRAM (Dynamic Random Access Memory) where a memory cell is formed of one capacitor and one MOS transistor in a compact structure.
FIG. 8 shows a structure of such a semiconductor memory device. Referring to FIG. 8, a semiconductor memory device includes a sense amplifier region 1, a plurality of memory cell regions 2 arranged in a matrix of rows and columns, four row decoders 3, four column decoders 4, a word line coupling region 5 provided parallel to the memory cell regions in the row direction, an empty region 6, a read/write circuit 7, and a control circuit 66.
The plurality of memory cell regions 2 are symmetrized about the dot dash line in FIG. 8. The memory cell regions 2 at the left and right sides of the dot dash line are further symmetrized about the sense amplifier region 1.
The sense amplifier region 1 is located between a pair of memory cell regions 2 provided in the column direction. This sense amplifier region 1 is provided with a sense amplifier, an input/output gate and the like as will be described afterwards.
The control circuit 66 generates various signals for controlling the semiconductor memory device according to a row address strobe signal /RAS, a column address strobe signal /CAS, a write signal /WE, and an address signal Add. The generated signals include a block selecting signal φ indicated by a hollow arrow in the figure, an internal address signal (merely referred to as an "address signal" hereinafter) applied to the row decoder 3 and the column decoder 4, and an internal read/write signal for controlling the read/write circuit 7.
The row decoder 3 selects a word line WL in response to an address signal to pull the selected word line WL to a H level (logical high). The sense amplifier provided in the sense amplifier region 1 amplifies the data of a memory cell connected to the selected word line WL. The column decoder 4 selects a desired bit from the memory cells of one row of the selected word line WL in response to an address signal.
The word line coupling region 5 serves to reduce the impedance of a word line WL.
FIG. 9 shows a structure of the word line WL indicated by the broken line in FIG. 8. Because the word line WL has a high resistance due to the fact that it is generally formed of a polysilicon layer, the time constant takes a high value when the word line rises. The resistance of a word line is reduced by short-circuiting the aluminum interconnection and the polysilicon interconnection in the word line coupling region 5 provided parallel to the memory cell regions 2 in the column direction. As a result, the time constant at the time of the rise of the word line is reduced to allow a higher speed of operation of the semiconductor memory device.
As an alternative of connecting the aluminum interconnection and the polysilicon interconnection, a buffer circuit formed of two stages of inverters may be provided in the word line coupling region 5, as shown in FIG. 10. This gives the advantage of preventing delay in the word line selecting signal. The word line coupling method and the method of providing a buffer circuit both have the impedance of the word line reduced.
FIG. 11 schematically shows a layout of the portion surrounded by the chain line with one dot in FIG. 8. Referring to FIG. 11, the portion surrounded by a chain line with one dot B includes a word line 40, bit lines BL and /BL, and a contact hole 41. Contact holes 41 are arranged in upper and lower stages so as not to form a contact with each other. The polysilicon layer and the aluminum interconnection are overlayed as shown in FIG. 9 to be connected by the contact hole 41 in the word line coupling region 5.
The empty region 6 is a region surrounded by the word line coupling regions 5 and the sense amplifier regions 1, establishing a margin in the layout. Although two MOS transistors 42 and 43 are provided in this region 6 as will be described afterwards with reference to FIG. 12, it is considered substantially as an empty region.
FIG. 12 is a circuit diagram showing the portion surrounded by a chain line with two dots A in FIG. 8 showing a structure of a conventional semiconductor memory device. Referring to FIG. 12, the sense amplifier region 1 to the left of the dot dash line includes NMOSFETs 7, 8, 11 and 12 serving as memory cell region selecting gates, NMOSFETs 9 and 10 serving as input/output gates, a circuit 39 including a sense amplifier and a bit line equalize circuit, and a sub-I/O line pair of SIO1 and /SIO1. The sense amplifier region 1 located at the right hand side of the dot dash line is similar to the sense amplifier region 1 located at the left hand side of the dot dash line, and includes NMOSFETs 25, 26, 29, and 30 serving as memory cell region selecting gates, NMOS transistors 27 and 28 serving as input/output gates, a circuit 39 including a sense amplifier and an equalize circuit, and a sub-I/O line pair of SIO3 and /SIO3.
The empty region 6 located at the left hand side of the dot dash line includes NMOSFETs 42 and 43 serving as block selecting gates. The empty region 6 located at the right hand side of the dot dash line includes NMOSFETs 44 and 45 serving as block selecting gates. The signal φ1 in FIG. 12 is a signal for selecting the block to the left of the dot dash line when attaining a high level. The signal φ2 is a signal for selecting the block to the right of the dot dash line. The signal φS1 selects the memory cell regions located at the left-hand side of the sense amplifier region 1 in the region to the left of the dot dash line. The signal φS2 selects the memory cell regions located at the right-hand side of the sense amplifier region 1 in the region to the left of the dot dash line. Similarly, signals φS3 and φS4 are signals for selecting the memory cell regions at the left-hand side and the right-hand side, respectively, of the sense amplifier region 1 in the region to the right of the dot dash line.
Signal BLEQ serves to equalize the potential of the bit line pair.
The circuit 39 equalizes the potential of the bit lines BL and /BL and detects the potential difference of bit lines BL and /BL. The details of this circuit 39 are shown in FIG. 13. Referring to FIG. 13, the circuit 39 includes a sense amplifier 39S responsive to sense amplifier driving signals φP and φN for detect-amplifying the potential difference of bit lines BL and /BL, and an equalize circuit 39E responsive to a bit line equalize signal BLEQ for equalizing the potential of bit lines BL and /BL to a half of the power supply potential Vcc. Sense amplifier driving signals φP and φN are complementary to each other.
FIG. 14 is a timing chart of the semiconductor memory device of FIG. 12.
The reading and writing operation of the data of memory cell 21 in FIG. 12 will be described with reference to the timing chart of FIG. 14.
At time t1, a row address signal is latched when the row address strobe signal /RAS attains a L level (logical low). At time t2, the signal φS1 for selecting a memory cell region attains a L level and the word line WL1 connected to the access gate of the memory cell 21 attains a H level according to the row address signal. The signal φS2 for selecting the memory cell regions of the righthand side maintains a H level. In response to signal φS2, the memory cell region selecting gates 7 and 8 are turned off and the memory cell region selecting gates 11 and 12 are turned on. Thus, the data of the memory cell 21 is read out to the bit line BL2, whereby a potential difference is generated between the bit line pair BL2 and /BL2.
At time t3, when the sense amplifier 39S is activated, the potential difference of the bit line pair BL2 and /BL2 is amplified. At time t4, the column decoder 4 pulls the column selecting signal Yi to a H level according to a column address signal. The block selecting signal φ1 attains a H level and the block selecting gates 42 and 43 are turned on. As a result, the bit line pair BL2 and /BL2, the sub-I/O line pair SIO2 and /SIO2, and the main I/O line pair GIO2 and /GIO2 are connected, whereby the potentials of the bit line pair BL2 and /BL2 are transmitted to the main I/O line pair GIO2 and /GIO2. The read/write circuit 7 shown in FIG. 8 detects the potential difference of the main I/O line pair GIO2 and /GIO2 to identify the data maintained in the memory cell 21. The data held in the memory cell 21 is logical high when the potential of the main I/O line GIO2 is higher than that of /GIO2, and is logical low when the potential of the main I/O line GIO2 is lower than that of /GIO2.
At time t5 when the write signal /WE attains a L level, the write data applied to the main I/O lines GIO2 and /GIO2 is supplied to bit lines BL2 and /BL2 via the sub-I/O lines SIO2 and /SIO2, whereby data is written into the memory cell 21.
Because the structure of FIG. 12 has the sub-I/O line pair and the main I/O line pair connected to the bit line pair when the column selecting signal Yi attains a H level, the column selecting signal Yi must be pulled up to the H level after the potential difference is amplified by the sense amplifier 39S.
This is because the sub-I/O lines and main I/O lines having a great parasitic capacitance will be connected to the bit line when the column selecting signal Yi is brought to a H level prior to a sense amplifying operation to result in a small potential difference between the bit lines BL2 and /BL2, leading to a possibility of erroneous operation caused by the sense amplifier failing to amplify the small potential difference.
There is a conventional circuit shown in FIG. 15 for solving such a problem. FIG. 15 is a circuit diagram showing an example of structure of a conventional semiconductor memory device. The semiconductor memory device of FIG. 15 differs from the semiconductor memory device of FIG. 12 in that NMOSFETs 46-49 serving as read out gates in the sense amplifier region located at the left side of the dot dash line, and NMOSFETs 52 and 53 for selecting a read out block in the empty region 6 located below the sense amplifier region 1 are added. Similarly, NMOSFETs 56-59 serving as read out gates in the sense amplifier region 1 located at the right-hand side of the dot dash line and NMOSFETs 62 and 63 for selecting a read out block in the empty region 6 provided beneath the sense amplifier region 1 are added. A sub-output line pair of SO1 and /SO1 exclusively for reading and a sub-input line pair of SI1 and /SI1 exclusively for writing are provided.
FIG. 16 is a timing chart for showing the operation of the semiconductor memory device of FIG. 15.
The operation of reading out data from the memory cell 21 of FIG. 15 and writing an inverted data will be described with reference to the timing chart of FIG. 16.
At time t1 where the row address strobe signal /RAS attains a L level, a row address signal is latched. The row decoder 3 pulls the word line WL1 to a H level according to the row address signal. In response, the address gate of the memory cell 21 is turned on, whereby the data in memory cell 21 is read out to the bit line pair BL and /BL. At time t3, the column selecting signal YRi is brought to a H level to conduct NMOSFETs 48 and 49, and the block selecting signal φ1 is brought to a H level to conduct NMOSFETs 52 and 53. Because the potential of bit line BL2 is higher than that of the bit line /BL2, NMOSFET 46 is turned on more heavily than NMOSFET 47. Therefore, the potentials of the sub-output line SO1 and the main I/O line GIO2 become lower than the respective potentials of the sub output line /SO1 and the main I/O line GIO2. The read/write circuit 7 detects the potential difference between main I/O lines GIO and /GIO to identify the data held in the memory cell 21. When the potential of the main I/O line GIO is lower than that of /GIO, the memory cell data is logical high. When the potential of the main I/O line GIO is higher than that of /GIO, the memory cell data is logical low.
As described above, the semiconductor memory device of FIG. 15 differs from the semiconductor memory device of FIG. 12 in that the column selecting signal YRi is brought to a H level before the sense amplifying operation and reads out the memory cell data to main I/O line pair GIO2 and /GIO2. This offers an advantage of a faster read out operation of the memory cell data to the main I/O line pair of GIO2 and /GIO2.
At time t4 when the write signal /WE is brought to a L level, the column selecting signal YWi attains a H level, whereby the data in the main I/O line is applied to the bit line. Then, the potential of the bit line BL2 is written to the memory cell 21.
The conventional semiconductor memory device of the above-described structure has the width W2 of the sense amplifier region 1 in the column direction of FIG. 15 increased in comparison with the width W1 of the sense amplifier region in the column direction of FIG. 12 for increasing the read out speed of data when the structure of FIG. 12 is implemented as shown in FIG. 15. This results in a problem of increase in the chip area.
SUMMARY OF THE INVENTION
An object of the present invention is to allow high speed access operation in a semiconductor memory device including a plurality of memory cell regions without increase in the chip area.
Another object of the present invention is to allow a high speed access operation in a semiconductor memory device including a plurality of memory cell regions by increasing the potential difference in bit lines at the time of data read out.
A further object of the present invention is to allow a high speed access operation in a semiconductor memory device including a plurality of memory cell regions by limiting the potential difference of bit lines at a constant value at the time of page mode operation.
A semiconductor memory device according to the present invention includes a plurality of memory cell regions, a main data input/output line pair, a sub-data input/output line pair, a plurality of data input/output controllers, a plurality of impedance reducing portions, a plurality of read circuits, and a plurality of write circuits. The plurality of memory cell regions are arranged in row and column directions. The main data input/output line pair transmits externally generated data and internally generated data. The sub data input/output line pair is provided in a region between memory cell regions in the column direction for transmitting data with respect to an adjacent memory cell region. The plurality of data input/output controllers are provided in a region between memory cell regions in the column direction for carrying out data input/output control between each bit line pair of an adjacent memory cell region in the column direction and the sub-data input/output line pair. The plurality of impedance reducing portions are provided between memory cell regions in the row direction for reducing impedance of a word line. The plurality of read circuits are provided in a region surrounded by the region in which the data input/output controllers are provided and by the region in which the impedance reducing portions are provided for detecting the potential difference of the sub-data input/output line pair to provide the same to the main data input/output line pair. The plurality of write circuits are provided in the same region where the read circuits are provided for transferring the data of the main data input/output line pair to the sub-data input/output line pair.
In operation, the read circuit detects the potential difference of the sub-data input/output line pair to provide the same to the main data input/output line pair, whereby the data read out speed is improved. The read circuits are provided in the region where the data input/output controllers are provided and in the region where the impedance reducing portions are provided, i.e. the region which was not conventionally used effectively. Therefore, the semiconductor memory device according to the present invention can carry out a high speed access operation without increase in the chip area.
A semiconductor memory device according to another aspect of the present invention includes a plurality of memory cell regions, a main data input/output line pairs, a plurality of sub-data input/output line pairs, a plurality of sense amplifiers, a plurality of input/output gates, a plurality of impedance reducing portions, a plurality of read circuits, and a plurality of write circuits. The plurality of memory cell regions are arranged in the directions of rows and columns, each including a plurality of word lines provided in the row direction, a plurality of bit lines provided in the column direction, and a plurality of memory cells provided at the crossings of each word line and each bit line. The main data input/output line pair transmits externally generated data and internally generated data. The plurality of sub-data input/output line pairs are provided between each pair of the memory cell regions in the column direction, wherein each transmits data with respect to an adjacent memory cell region. The plurality of sense amplifiers are provided between each pair of memory cell regions in the column direction, wherein each detects the potential difference in each bit line pair of an adjacent memory cell region. The plurality of input/output gates are provided between each pair of memory cell regions in the column direction, wherein each is connected between each bit line pair of an adjacent memory cell region and the sub-data input/output line pair. The plurality of impedance reducing portions are provided between memory cell regions in the row direction for reducing impedance of a word line. The plurality of read circuits for detecting the potential difference in the sub-data input/output line pair to provide the same to the main data input/output line pair are provided in a region surrounded by a region in which input/output gates and sense amplifiers are provided and by the region in which the impedance reducing portions are provided. The plurality of write circuits are provided in the same region where the read circuits are provided for transferring data on the main data input/output line pair to the sub-data input/output line pair.
In operation, the plurality of read circuits are provided in each region surrounded by the region in which sense amplifiers and input/output gates are provided and by the region in which impedance reducing portions are provided, whereby a high speed access operation of a semiconductor memory device can be carried out without increase in chip area.
According to a further aspect of the present invention, a semiconductor memory device has a read circuit activated right after the activation of the amplifier.
In operation, the read circuit is activated before the activation of the sense amplifier for the speed enhancement, because the read circuit does not disturb the operation of the sense amplifier. The sense amplifier amplifies the potential difference of the bit line, and the potential difference is transferred to the sub-data input/output line pair via the input/output gate. If the potential difference in the sub-data input/output line pair is too great, the time required for pulling down the sub-data input/output line pair will be increased. Therefore, there is a possibility of a disadvantage in high speed in page mode operation.
According to still another aspect of the present invention, a semiconductor memory device further includes a circuit for limiting the potential difference of the sub-data input/output line pair to a constant potential. In operation, because the potential difference of the sub-data input/output line pair is limited to a constant potential, a high speed access operation of a semiconductor memory device can be carried out even in page mode operation.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a structure of a semiconductor memory device according to an embodiment of the present invention.
FIG. 2 is a timing chart showing an operation of the semiconductor memory device of FIG. 1.
FIG. 3 is a structure of a semiconductor memory device according to a second embodiment of the present invention.
FIG. 4 is a timing chart showing an operation of the semiconductor memory device of FIG. 3.
FIG. 5 is a timing chart showing another operation of the semiconductor memory device of FIG. 1, which is a third embodiment of the present invention.
FIG. 6 is a structure of a semiconductor memory device according to a fourth embodiment of the present invention.
FIG. 7 is a timing chart showing an operation of the semiconductor memory device of FIG. 6.
FIG. 8 shows an entire structure of a semiconductor memory device of the background art.
FIG. 9 is a diagram for describing a structure of the word line shown in FIG. 8.
FIG. 10 is a diagram showing another structure of the word line of FIG. 8.
FIG. 11 shows in details the portion surrounded by the chain line with one dot B of FIG. 8.
FIG. 12 is a structure of a conventional semiconductor memory device.
FIG. 13 is a circuit diagram showing in details the circuit 39 of FIG. 12.
FIG. 14 is a timing chart showing an operation of the semiconductor memory device of FIG. 12.
FIG. 15 is a structure showing another example of a conventional semiconductor memory device.
FIG. 16 is a timing chart showing an operation of the semiconductor memory device of FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a circuit diagram showing an embodiment of the present invention. The semiconductor memory device of FIG. 1 differs from the semiconductor memory device of FIG. 12 in that a read gate 6r, a write gate 6w, and an equalized circuit 6E for equalizing the potentials of a sub-I/O line pair are provided in each empty region 6, and that the block selecting signal is divided into a block selecting signal for writing /W and a block selecting signal for reading φR.
Because the semiconductor memory device of FIG. 1 is symmetrized about the dot dash line, the portion to the left of the dot dash line will be described in the following description.
The write gate 6W includes NMOSFETs 13 and 14. Each NMOSFET includes one electrode (drain electrode or source electrode), the other electrode (source electrode or drain electrode), and a gate electrode. The NMOSFET 13 has one electrode connected to the sub-I/O line SIO1, the other electrode connected to the main I/O line /GIO2, and the gate electrode connected to receive a block selecting signal φW1 together with the NMOSFET 14. The NMOSFET 14 has one electrode connected to the sub-I/O line SIO1, and the other electrode connected to the main I/O line GIO2.
The read gate 6R includes NMOSFETs 15-20. The NMOSFET 15 has one electrode connected to the main I/O line /GIO2, the other electrode connected to one electrode of the NMOSFET 17, and the gate electrode connected to receive the block selecting signal φR1 together with the gate electrode of the NMOSFET 16. The NMOSFET 16 has one electrode connected to the main I/O line GIO2, and the other electrode connected to the one electrode of the NMOSFET 18. The NMOSFET 17 has the other electrode connected to receive the ground potential Vss, and the gate electrode connected to the sub-I/O line /SIO1. The NMOSFET 18 has the other electrode connected to receive the ground potential Vss, and the gate electrode connected to the sub-I/O line SIO1.
The equalize circuit 6E includes NMOSFETs 19 and 20. The NMOSFET 19 has one electrode connected to the sub-I/O line /SIO1, the other electrode connected to receive a potential of 1/2 Vcc which is a half of the power supply voltage, and the gate electrode connected to receive the bit line equalize signal BLEQ together with the gate electrode of the NMOSFET 20. The NMOSFET 20 has the other electrode connected to the sub-I/O line SIO1.
FIG. 2 is a timing chart of the semiconductor memory device of FIG. 1.
The operation of reading out the memory cell 21 having a data of a H level stored therein and rewriting thereof will be described hereinafter with reference to the timing chart of FIG. 2.
The bit line equalize signal BLEQ is pulled up to a H level when the row address strobe signal /RAS attains a H level. In response, the bit line equalize circuit 39E (FIG. 13) precharges bit lines BL and /BL to 1/2 Vcc. Also, the NMOSFETs 19 and 20 of the equalize circuit 6E are turned on to precharge the sub-I/O lines SIO and /SIO to 1/2 Vcc.
At time t1 when the row address strobe signal /RAS is pulled to a L level, a row address signal is latched. At time t2, a signal φS1 selecting a memory cell region left-side of the sense amplifier region is brought to a L level, and a word line WL1 corresponding to the latched row address signal rises. The signal φS2 that selects the memory cell region of the right side of the sense amplifier region maintains a H level. As a result, the data in the memory cell 21 is read out to the bit line pair of BL2 and /BL2. At time t3, the block selecting signal φR1 is brought to a H level, and the column selecting signal Yi attains a H level according to a row address signal. In response, NMOSFETs 15 and 16, the input/output gates 9 and 10 turn on. As a result, the bit line pair of BL2 and /BL2 is connected to the sub-I/O line pair of SIO1 and /SIO1. However, the sub-bit line pair of BL2 and /BL2 is not connected to the main I/O line pair of GIO2 and /GIO2 because the NMOSFETs 13 and 14 are not conductive.
Because the bit line pair of BL2 and /BL2 is not connected to the main I/O line pair of GIO2 and /GIO2, reduction in the potential difference appearing on the bit line pair of BL2 and /BL2 is significantly smaller than that of FIG. 12. This advantage can be explained as follows. As shown in FIG. 8, the length L1 of the sub-I/O lines SIO and /SIO is considerably shorter than the length L2 of the main I/O line pair of GIO and /GIO. Therefore, the parasitic capacitance of the sub-I/O is much smaller than that of GIO. This means that the decrease in potential difference of the bit line pair as a result of the bit line pair of BL2 and /BL2 being connected to the sub-I/O lines SIO1 and /SIO1 on account of the column selecting signal Yi attaining a H level is considerably smaller than the case where the bit line pair is connected to both the sub-I/O lines and the main I/O line as a result of the column selecting signal pulled up prior to a sense-amplification in the structure of FIG. 12.
Therefore, according to the structure of FIG. 1, the sense amplifier will not fail to amplify the potential difference of the bit lines even if the column selecting signal Yi is pulled up to a H level prior to the sense-amplification.
At time t3, the potential of the sub-I/O line SIO1 becomes higher than the potential of /SIO1 because the sub-I/O lines SIO, connected to bit line BL2, which hold higher potential than /BL2. At time t4, the potential difference of the sub-I/O line pair can be increased by the difference in this conductivity. Because the block selecting signal φR1 attains a H level at this time, NMOSFETs 15 and 16 are conductive. Therefore, the potential of the main I/O line GIO2 becomes lower than the potential of /GIO2. The read/write circuit 7 detects the potential difference between the main I/O lines of GIO2 and /GIO2 to identify the data held in the memory cell 21. If the potential of the main I/O line GIO2 is lower than that of /GIO2, the data in memory cell 21 is identified as attaining a H level. If the potential of the main I/O line GIO2 is higher than that of /GIO2, the data in the memory cell 21 is identified as a L level.
At time t5 when the write signal /WE is pulled down to a L level, the column selecting signal Yi and the block selecting signal φW1 attain a H level, whereby the data in the main I/O line pair of GIO2 and /GIO2 are transmitted to bit lines BL2 and /BL2 via the sub-I/O line pair of SIO2 and /SIO2. Thus, the potential of the bit line BL2 is written into the memory cell 21.
The structure of the semiconductor memory device of FIG. 1 has a width W1 of the sense amplifier region identical to that in the structure of the semiconductor memory device of FIG. 12. However, according to the structure of the semiconductor memory device of FIG. 1, the column selecting signal is activated prior to the amplification of the potential difference of the bit line pair by the sense amplifier to read out data to the main I/O line, so that data read out from a memory cell can be carried out at a high speed, as in the case of the structure of FIG. 15.
Since the structure of FIG. 1 has the NMOSFETs for precharging the potential of the sub-I/O line to 1/2 Vcc both in the sense amplifier region 1 and the region 6 surrounded by the word line coupling regions 5, the equalize circuit 6E in region 6 can be omitted as shown in FIG. 3 with only a read gate 6R and a write gate 6W provided.
FIG. 3 is a circuit diagram showing a second embodiment of the present invention. The operation of precharging the sub-I/O lines SIO1 and /SIO1 to 1/2 Vcc in the circuit of FIG. 3 will be described with reference to the timing chart of FIG. 4.
The timing chart of FIG. 4 differs from the timing chart of FIG. 2 in that at least one of the column selecting signal Yi among the column selecting signals Yi provided to the region sense amplifier is pulled up to a H level when the row address strobe signal /RAS attains a H level. The other waveforms are similar to those of FIG. 2.
In the beginning, at least one of the column selecting signal Yi is pulled up to a H level when the row address strobe signal /RAS attains a H level. In response to this column selecting signal, the corresponding input/output gate is turned on, whereby the bit lines BL and /BL are connected to the corresponding sub-I/O lines SIO and /SIO. Therefore, the sub-I/O line pair is precharged to 1/2 Vcc. The operation succeeding time t1 is similar to that of FIG. 1.
Although the operation of the semiconductor memory device of FIG. 1 was described according to the timing chart of FIG. 2, the semiconductor memory device of FIG. 1 may be operated according to the timing chart of FIG. 5. FIG. 5 is a timing chart showing a third embodiment of the present invention. The timing chart of FIG. 5 differs from the timing chart of FIG. 2 in that the read gate 6R is activated at time t4 right after time t3. The operation of the semiconductor memory device of FIG. 1 will be described according to the timing chart of FIG. 5.
The operation at time t1 and t2 is similar to that of FIG. 2. At time t3, the sense amplifier is activated, and the potential difference of bit lines BL2 and /BL2 is amplified. At the time of or right after the activation of the sense amplifier (time t4), the column selecting signal Yi is pulled up to a H level.
The timing chart of FIG. 5 differs from the timing chart of FIG. 2 in that the column selecting signal Yi is pulled up simultaneously or right after the sense amplification. Therefore, the sense amplifier operation is more reliable because of a greater potential difference of the bit line pair (BL2 and /BL2) which is to be amplified by the sense amplifier. Because it is not necessary to wait until a sufficient potential difference is established in the bit line to bring the column selecting signal Yi to a H level, the read out speed of data is increased. The operation succeeding time t4 is similar to that of FIG. 2.
The semiconductor memory devices of FIGS. 1 and 3 have a possibility of preventing high speed operation in page mode operation because the potential difference of the sub-I/O line pair is increased. Therefore, an approach is considered to limit the potential difference of the sub-I/O line pair for the purpose of obtaining high speed operation even in page mode.
FIG. 6 is a circuit diagram showing a fourth embodiment of the present invention. The semiconductor memory device of FIG. 6 differs from the semiconductor memory device of FIG. 1 in that load transistors 69-72 for limiting the amplitudes of the sub-I/O lines SIO and /SIO, transistors 89 and 90 for equalization, and control signals φZRi and SIOEQi are included. For the purpose of describing the operation of page mode, bit lines BL5-BL8 and /BL5-/BL8 of one column, corresponding NMOSFETs 73-84, memory cells 85-88, and a column selecting signal Y2 are added.
FIG. 7 is a timing chart showing the operation of the semiconductor memory device of FIG. 6.
The operation of reading out data from memory cells 21 and 85 and then writing a data of a H level into the memory cell 85 is described with reference to the timing chart of FIG. 7, in the case where the memory cell 21 stores a data of a H level and the memory cell 85 stores a data of a L level.
Before time t1, the row address strobe signal /RAS attains a H level, and the semiconductor memory device is in a standby state. The bit line pair of BLi and /BLi and the sub-I/O line pair of SIOi and /SIOi are precharged to 1/2 Vcc because the equalize signal BLEQi and SIOEQi are both at a H level.
At time t2, the word line WL1 is pulled up according to a row address signal, whereby the data in memory cells 21 and 85 are read out to bit lines BL2 and BL6, respectively. At time t3, the sense amplifier is activated. At a substantially same time of t4, the equalize signal SIOEQ1 is pulled up to a H level according to the column address signal 1 (refer to Add of FIG. 7). In response, the NMOSFET 89 is turned on and the sub-I/O line pair of SIO1 and /SIO1 is equalized. At time t5 right after time t4, the column selecting signal Y1 attains a H level, the signal φR1 for selecting a memory cell region attains a H level, and the signal φZR1 attains a L level. In response to a column selecting signal Y1 of a H level, the input/output gates 9 and 10 are turned on, whereby the potentials of the bit line pair of BL2 and /BL2 are transmitted to the sub-I/O line pair of SIO1 and /SIO1. At this time, PMOSFETs 69 and 70 are turned on, whereby the sub-I/O line pair of SIO1 and /SIO1 are pulled up to the power supply voltage of Vcc. Therefore, the amplitudes of the sub-I/O line pair of SIO1 and /SIO1 are limited as shown in FIG. 7. Although the amplitudes of the sub-I/O line pair are limited as described above, there is a potential difference sufficient for the operation of the read gate 6R, so that a read out signal is transmitted to the main I/O line pair of GIO1 and /GIO1.
Then, the address changes from the column address signal 1 to the column address signal 2, and the equalize signal SIOEQ1 attains a H level. Immediately thereafter, the column selecting signal Y2 attains a H level. In response to this column selecting signal Y2, the sub-I/O line pair of SIO2 and /SIO2 are connected to bit lines BL6 and /BL6.
Although it is necessary to invert the potentials of the sub-I/O lines in this case, the amplitudes of the sub-I/O lines are limited and equalized by the equalize signal SIOEQ1 through the function of pull-up transistors 69 and 70. Therefore, the potentials of the sub-I/O lines can be inverted at a high speed. The inverted potentials of the sub-I/O lines are detected by the read gate 6R, whereby the potentials of the main I/O lines are inverted.
At time t7 when the write signal /WE is pulled down to a L level, signals φR1, φZR1, and φW1 attain a L level, a H level, and a H level, respectively. In response, NMOSFETs 13 and 14 (write gate 6W) are turned on, and the data transmitted to the main I/O lines GIO2 and /GIO2 are transmitted to the sub-I/O lines SIO2 and /SIO2. However, because pull-up transistors 69 and 70 are turned off by the signal ZR1, the signals transmitted to the sub-I/O lines attain a full swing. The signals pulled up to the full swing level are transmitted to bit line pair of BL6 and /BL6 via input/output gates 75 and 76. The signal transmitted to bit line pairs BL6 and /BL6 is written into the memory cell 85. Thus, the data of a L level stored in the memory cell 85 can be rewritten to a data of a H level.
Although the semiconductor memory device of FIG. 6 has the sense amplifier activated prior to the column selecting signal attaining a H level, the column selecting signal may be raised prior to the activation of the sense amplifier as in the case of the semiconductor memory device of FIG. 1.
Although the semiconductor memory device of FIG. 1 does not include the NMOSFETs 89 and 90 of FIG. 6, these NMOSFETs 89 and 90 may be added to the semiconductor memory device of FIG. 1, whereby control is carried out by an equalize signal BLEQ.
Although the semiconductor memory device of FIG. 6 has pull-up transistors 69-72 and equalizing transistors 89 and 90 provided for the purpose of high speed operation in page mode, the operation in the page mode can be carried out in a sufficiently high speed even if only either of the pull up transistors or the equalize transistors are provided.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. | A semiconductor memory device is provided having a read out gate for detecting and providing to a main I/O line pair the potential difference of a sub-data input/output line pair, and a write gate for transferring data of the main I/O line pair to the sub-data input/output line pair in an empty region surrounded by a sense amplifier region and a word line coupling region. By providing the read out gate and the write gate in the empty region which was not conventionally used, the access operation can be carried out at high speed without increasing the chip area of the semiconductor memory device. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/EP2004/008301, filed Jul. 23, 2004, which was published in the German language on Feb. 10, 2005, under International Publication No. WO 2005/012661 A1, and the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a surface drainage device.
[0003] In line drainage systems water derived from the surface is generally conducted into an inlet chamber, sink trap or similar container from which it is then transferred into a channel system. If there is no gradient in the surrounding terrain, the depths of the consecutive channels in the system are chosen to be such that their bottom levels form a stepwise gradient. Depending on the site at which the channels are coupled to the inlet chambers, they therefore differ in height, in particular with respect to the internal profile.
[0004] To enable channels of different heights to be coupled to an inlet chamber, various constructions are known. In particular, attempts have already been made to couple trains of channels by means of insertion parts that have different heights, or can be coupled at different heights, as is known, for example, from German published patent applications DE 24 47 871 A1, DE 26 15 800 A1 and DE 44 25 940 A1 and German utility model DE 295 03 911 U1. The known systems, however, are of very elaborate construction, which affects both their manufacture and also the effort of installing them, in particular when it comes to adjusting them with respect to the various channel heights.
BRIEF SUMMARY OF THE INVENTION
[0005] It is an objective of the present invention to provide a surface drainage device that reduces the effort required for both manufacture and assembly at the construction site.
[0006] This objective is achieved in the case of a surface drainage system, in particular an inlet chamber, sink trap, branch channel, or similar drainage device, to which a drainage channel or similar water-conducting element is to be attached, in that it comprises at least one wall section for attachment of the water-conducting element, wherein the wall section comprises at least one flat section made of an elastomeric material.
[0007] An aim of the invention is that the drainage device, which itself consists of massive material that can support heavy loads, is combined with an elastomeric material or is constructed in part of such material, so that simple tools can be used to adapt this wall section to the water-conducting element that is to be coupled thereto. Therefore, less effort is required, both for manufacture and for assembly. The installation of several such wall sections in the drainage device is also easily possible.
[0008] Preferably, the surface drainage device is cast from concrete, in particular concrete polymer, which ensures high stability of the overall arrangement as well as a good bonding connection between the material of the surface drainage device and the elastomeric section.
[0009] Preferably, the flat section made of elastomeric material is poured into a surrounding wall section, and hence merely constitutes a section that is part of the associated wall. As a result, adequate stability of the overall arrangement is guaranteed. The casting process generates a fluid-tight connection between the cast element and the inlet chamber.
[0010] Preferably, the flat section is provided at its edge with an anchoring section by which a firm connection between the flat section and the device as a whole is ensured. The anchoring section is oriented at least partially at an angle to a main plane within which the flat section extends, or comprises a thickening, such that a stable and tightly sealed anchoring can be produced by simple means.
[0011] Preferably, the flat section comprises template arrangements that each correspond to an inner profile of a water-conducting element that could be attached to the flat section, so that the template can be used to cut out the flat section in correspondence with the required inner profile. This is made possible in particular by the fact that the channels are customarily standardized with respect to their height, so that the template with its various markings can be designed in advance in accordance with the various channel heights.
[0012] The template arrangements are preferably provided on a side of the flat section that faces away from the water-conducting element that is to be attached. This makes it possible for the assembler to view the template arrangement in its entirety, because it is freely and openly exposed.
[0013] The template arrangements preferably comprise a plurality of grooves for positioning a knife or similar cutting tool and marking its course. Hence, only very little skill is needed to undertake correct positioning and correct cutting of the elastomeric wall section.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
[0015] FIG. 1 is a schematic perspective view showing the structure of a drainage device with a wall section made of elastomeric material according to one embodiment of the invention;
[0016] FIG. 2 is a front view of the arrangement according to FIG. 1 ;
[0017] FIG. 3 is a section along the line III-III in FIG. 2 ;
[0018] FIG. 4 is a section along the line IV-IV in FIG. 2 ;
[0019] FIG. 5 is a section along the line V-V in FIG. 4 ;
[0020] FIG. 6 is a front view of a wall section;
[0021] FIG. 7 is a rear view of a wall section;
[0022] FIG. 8 is a section along the line VIII-VIII in FIG. 7 ;
[0023] FIG. 9 is a view along the line IX-IX in FIG. 7 ;
[0024] FIG. 10 is a view along the line X-X in FIG. 7 ;
[0025] FIG. 11 is a schematic sectional view of a vertical section through an embodiment of a surface drainage device in accordance with the invention, with attached water-conducting element prior to adjustment of the flat section;
[0026] FIG. 12 is a view similar to that in FIG. 11 , but after adjustment;
[0027] FIG. 13 is a perspective view of another embodiment of the invention, similar to that in FIG. 1 ;
[0028] FIG. 14 is a front view of the arrangement according to FIG. 13 ;
[0029] FIG. 15 is a section along the line XV-XV in FIG. 14 ;
[0030] FIG. 16 is a section along the line XVI-XVI in FIG. 14 ;
[0031] FIG. 17 is a section along the line XVII-XVII in FIG. 16 ;
[0032] FIG. 18 is a front view of the flat section according to FIG. 13 ;
[0033] FIG. 19 is a back view of the flat section according to FIG. 18 ;
[0034] FIG. 20 is a section along the line XX-XX in FIG. 19 ;
[0035] FIG. 21 is a view along the line XXI-XXI in FIG. 19 ; and
[0036] FIG. 22 is a view along the line XXII-XXII in FIG. 19 .
[0037] In the following description, the same reference numerals are used for identical parts and parts with identical actions.
DETAILED DESCRIPTION OF THE INVENTION
[0038] It should also be emphasized that the shape and the intended use of the drainage device according to FIG. 1 or 13 are not limited. This component can be an inlet chamber, a sink trap or also a drainage channel to which additional channel elements are to be attached in order to form a T-piece or a crossing.
[0039] As shown in FIG. 1 , an inlet chamber 1 is provided, on the upper side of which a cover grating is provided as usual. The inlet chamber 1 comprises a wall section 10 , in which a cutout 11 is provided. The cutout 11 is shaped so that the maximal height of the profile of a drainage channel to be joined thereto can be connected so as to be flush therewith.
[0040] Within the wall section 10 , closing off part of the cutout 11 , a flat section 20 is provided made of an elastomeric material, in particular a soft plastic or rubber material. On the surface of the flat section 20 that can be seen from the interior of the inlet chamber 1 , as shown in FIG. 5 , there are template arrangements 22 which, as shown in FIG. 4 , each comprise one of a series of grooves that are separated from one another by ridges. In this exemplary embodiment an upper edge 24 of the flat section 20 is configured such that it corresponds to the inner profile of a drainage channel with minimal height. The grooves, i.e., template markings, shown in FIGS. 4 and 5 are shaped so as to correspond to the (standardized) channel heights for various channels in a gradient sequence. Therefore, any of the channels in the gradient sequence can be attached, and it is not necessary to begin with a particular channel as has previously been the case.
[0041] The flat section 20 comprises at its outer edges anchoring sections 21 , which are shown very clearly in particular in FIG. 10 . These anchoring sections 21 are cast into the (concrete polymer) material of the inlet chamber 1 , i.e., into its wall section 10 , so that it is impossible for the flat section 20 to be torn out, and a fluid-tight connection is created between the poured-in template arrangement and the concrete polymer.
[0042] The procedure for assembly begins with the placement of a channel 30 against the inlet chamber 1 , as shown in FIG. 11 . A front surface 33 of the channel 30 thus abuts against a planar outer surface 25 of the flat section 20 . In the situation shown in FIG. 11 , the inner profile 31 of the channel 30 is deeper than the upper edge 24 of the flat section 20 . Now, so as to create a smooth transition, a knife is inserted into a groove 23 and passes through the flat section 20 to a depth such that the knife is in contact with the inner profile 31 of the drainage channel 30 . Then, the knife is used to cut all around the inner profile 31 of the channel 30 , so that a corresponding strip is separated from the flat section 20 , until the shape shown in FIG. 12 is produced. Now a sealing trough 32 provided at the end face of the channel 30 is filled with a sealing material, which simultaneously forms a firm connection with both the material of the channel 30 and the material of the flat section 20 , so that the transition from the channel 30 to the sink trap 1 is tightly sealed.
[0043] The embodiment of the invention shown in FIGS. 13-22 differs from that according to FIGS. 1-12 in that the upper edge 24 of the flat section 20 is positioned at substantially the full height of the inlet chamber 1 , which offers advantages during the process of pouring in the flat section 20 .
[0044] It is of course also possible for the flat section 20 to be provided with an anchoring section 21 over its entire periphery, so that the wall section it forms in a drainage device, in particular a drainage channel, is tightly sealed and need not be cut out unless it is needed for coupling to an additional channel element at the side, i.e., to form a T-piece. It is likewise possible to install a flat section 20 made of elastomeric material at the floor of a surface drainage device, so that outlet pipes can be attached.
[0045] 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 this invention 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. | A surface drainage device, in particular a sink tank is provided for connection to a drainage device or similar water-conducting element. At least one wall section of the surface drainage device is provided for connection to the water-conducting element and includes at least one flat section that is made of an elastomeric material, so that it can be adapted for the connection by a simple tool. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates broadly to methods and apparatus for controlling admission to rides at an amusement park. More particularly, this invention relates to methods and apparatus for controlling admission based on the height and/or weight (and optionally age) of a prospective rider.
[0003] 2. State of the Art
[0004] Every year many children are injured (some killed) because they were riding on an amusement park ride which was inappropriate for their stature. While it is common practice to measure a child's height prior to admitting the child to a particular ride, the measurement is informal and depends on the judgment of a human attendant. The typical measurement apparatus is simply a mark on a wall against which a child stands and is observed by the ride operator. Often there will be many children crowding around and this will interfere with the ride operator's correct assessment of the child's height. The child may take the opportunity of crowded conditions to stand on his or her toes, unnoticed, so that s/he appears taller than s/he actually is.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of the invention to provide methods and apparatus for controlling admission to individual rides at an amusement park.
[0006] It is another object of the invention to provide methods and apparatus which do not rely on human judgment for controlling admission to individual rides.
[0007] It is a further object of the invention to provide automated methods and apparatus for controlling admission to individual rides.
[0008] It is also an object of the invention to provide methods and apparatus for controlling admission to individual rides which determines at once which rides are appropriate and which are inappropriate for a particular child.
[0009] It is an additional object of the invention to provide methods and apparatus for controlling admission to individual rides whereby a child is prevented from riding inappropriate rides.
[0010] In accord with these objects, which will be discussed in detail below, the methods of the invention include measuring a child's height and/or weight, and optionally obtaining age information, and encoding a data carrier with information relating to the height and/or weight (and optionally age) of the child, and reading the data carrier at ride entry points to determine whether the child will be admitted to the ride. The data carrier may be a “swipe card” or other machine readable device which must be presented at the entrance to each ride. The entrance to each ride is provided with an electronic entry control gate which is operated by the data carrier. According to other aspects of the invention, after information about the child is obtained, the child's height and/or weight (and optionally age) is compared to a database and a printout listing rides to which the child will and/or will not be admitted is generated for the child and/or the child's parents.
[0011] The apparatus of the invention include an electronic measuring apparatus, a database, a plurality of data carriers, a data carrier encoder, a printer, and admission control equipment at each ride. The admission control equipment includes an electronic turnstile, a data carrier reader, and means for unlocking the turnstile based on the data read from the data carrier. The measuring apparatus includes sensors to determine whether the child is standing on his/her toes. According to one embodiment, the data carrier is a bar coded bracelet which cannot be removed from the child's wrist without destroying it. However, the data carrier can be a magnetic stripe card, a bar coded card, an RFID device, etc.
[0012] Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic view of a measurement and data carrier encoding apparatus according to the invention;
[0014] FIG. 2 is a top plan view of the measurement apparatus;
[0015] FIG. 3 is a schematic view of a data reader and electronic gate controller according to the invention;
[0016] FIG. 4 is a simplified flow chart illustrating a measurement and data carrier encoding method according to the invention; and
[0017] FIG. 5 is a simplified flow chart illustrating an admission control method according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Turning now to FIG. 1 , an exemplary apparatus 10 according to the invention includes an LED emitter 12 , a photo detector 14 , a weighing platform 16 , a processor with a database 18 , a keypad 19 , a data carrier encoder 20 , a printer 22 , and a plurality of data carriers 24 . The LED emitter 12 includes a plurality of LEDs arranged in a vertical column spaced apart from each other, e.g. one inch apart. The photo detector 14 includes a plurality of photo detectors arranged in a vertical column corresponding to the LEDs. As shown in FIG. 1 , a child C standing between the emitter 12 and detector 14 will block some beams of light B up to his or her height, above which beams of light L will pass and be detected by the detector 14 . By determining which detectors detect light and which do not, the child's height can be determined.
[0019] As shown in FIG. 2 , the weighing platform 16 includes four pressure sensors 16 a - 16 d . In order to operate the device, the child must place the left foot heel on sensor 16 a , the left foot toes on sensor 16 b , the right foot heel on sensor 16 c , and the right foot toes on sensor 16 d . Only when all four sensors detect pressure will the child's height be measured. This prevents the child from standing on toes to appear taller.
[0020] The PC 18 is coupled to the photo detector array 14 and to the weighing platform 16 including the sensors 16 a - 16 d . Preferably the PC 18 is also coupled to the LED array 12 so that it is only turned on when a child is standing on the weighing platform. The database in the PC 18 includes height and/or weight data (and optionally age data) for every ride in the amusement park. After the PC 18 is provided with the height, weight, and age (via the keypad 19 ) of the child, the attached encoder 20 is used to encode a data carrier 24 with information relating to the height, weight, and age of the child which will be used to control access to individual rides. Optionally, the PC 18 is coupled to a printer 22 which is used to print a list of rides from the database, the list consisting of the rides to which the child will be granted access and/or the rides to which the child will be denied access. The data encoded on the card can be an indication of the child's height and weight, e.g. inches and pounds, optionally the child's age, an indication of the rides the child will be admitted to, an indication of the rides the child will not be admitted to, a classification code, or some other data or datum which relates to the child's height, weight and age and can be used to determine admission to rides.
[0021] FIG. 3 illustrates an admission control system 100 for an amusement park ride. The system 100 includes an electronically controlled turnstile 102 coupled to a data reader and controller 104 . The data reader reads the data carrier ( 24 in FIG. 1 ) and determines from the data encoded therein whether to activate the turnstile and allow the child admission to the ride. It will be appreciated that the exact operation performed by the controller will depend on the data encoded on the carrier 24 . If the data is an indication of the child's height/weight, the controller will perform a simple comparison of the child's height/weight to the height/weight requirement for this particular ride which will be stored in the controller. If the data includes an indication of the rides to which the child is permitted admission, the controller will read the list to determine whether this particular ride is contained in the list. A similar function with opposite result will be performed if the data includes an indication of the rides to which the child is denied admission. Still another possibility is to classify the child's height/weight into one of a plurality of groups and to classify the rides similarly. It will be appreciated that depending on the nature of the data used to determine ride access, the database 18 shown in FIG. 1 may not be needed to encode the data carrier 24 .
[0022] It will further be appreciated that access to rides may also depend on a child's age in conjunction with the height and/or weight of the child. In this case, the controller will perform the necessary operation to determine access. Also, access to some rides may depend on whether the child is accompanied by a parent. Thus, according to another aspect of the invention, a data carrier for the child's parent is issued and linked in some way (e.g. via a database entry) to the data carrier of the child. The controller then will determine whether the parent's data carrier has been presented before admitting the child.
[0023] FIG. 4 illustrates a method of measuring the child and encoding the data carrier according to the invention. Starting at 200 , the apparatus ( 10 in FIG. 1 ) waits until presence of a child is detected at 202 . The child's presence can be detected by sensing weight on the weighing platform ( 16 in FIG. 1 ) or by detecting a break in one of the light beams (B in FIG. 1 ) if the apparatus is arranged to leave the LEDs ( 12 in FIG. 1 ) on rather than turn them on only when weight is sensed. At 204 the four foot sensors ( 16 a - 16 d in FIG. 1 ) are examined. If it is determined at 204 that fewer than all four sensors detect pressure, an announcement is made at 206 . The announcement may be audible, visual, or both and presents the child with instructions to stand with heels and toes touching the appropriate spots on the weighing platform. In order to assist the child, concentric outlines of different size feet can be painted onto the weighing platform. For an entertaining aesthetic effect, outlines of feet in flashing LEDs can be provided on the weighing platform.
[0024] Once it is determined at 204 that the child is standing in the correct place, the child's height, weight and, optionally, age are measured at 208 . According to the illustrated embodiment, a database lookup is performed at 210 to determine which rides are appropriate for a child of this height/weight. At 212 , a list of rides is printed and a data carrier is encoded. The data carrier and printout are then dispensed at 214 . As discussed above, the database lookup and the printout are not essential to the invention. The method of measuring and encoding could directly encode the child's height/weight onto the data carrier for comparison later at admission control points.
[0025] FIG. 5 illustrates a method of controlling admission to rides using the data carrier which, as discussed above, may be attached to the child's wrist. Starting at 300 , the device ( 100 in FIG. 3 ) waits until a data carrier is detected. Detection may be accomplished when the child holds the data carrier next to a scanner. In the case of and RFID data carrier, detection can be accomplished by an RF detector when the child is adjacent the turnstile ( 102 in FIG. 3 ). After the data carrier is detected at 302 , its contents are read at 304 . According to the illustrated embodiment, a database lookup is then performed. This lookup could be a simple comparison of the height/weight data read at 304 to a minimum height/weight requirement stored in the data reader and controller ( 104 in FIG. 3 ). However, if the data carrier were encoded with a list of rides, then that list would constitute the database that is looked up at 306 to determine whether or not the present ride is on the list encoded into the data carrier. In either case, after the lookup or comparison, it is determined at 308 whether the child is eligible to be admitted to this ride. If the child is to be denied admission, an announcement is made at 310 and the process returns to 300 . The announcement may be audible, visual, or both and will advise the child that admission to this ride is denied because of height/weight requirements. Optionally, the announcement may include a suggestion of one or more nearby rides for which the child is qualified. This information would be obtained from the database lookup at 306 . If, on the other hand, the child is to be allowed admission, the turnstile is unlocked at 312 . As shown in FIG. 3 , the turnstile 102 is preferably designed to minimize the likelihood that two children could pass through at the same time.
[0026] There have been described and illustrated herein several embodiments of a method and apparatus for controlling the admission to amusement park rides. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while the methods and apparatus have been described for restricting admission to amusement park rides based on height/weight, the methods and apparatus can be used in conjunction with other methods and apparatus. For example, the data carrier and admission control points could also be used for billing. The data carrier can be related to a credit or debit account and that account can be credited/debited every time the child gets on a ride. The data carrier can be encoded with demographic data and used to poll the popularity of different rides among different demographic groups. The data carrier can be encoded with information identifying the child and can be used to locate the child. In addition, while particular types of height and weight measuring apparatus have been disclosed, it will be understood that other apparatus can be used. For example, and not by way of limitation, height could be determined by image analysis of a video image of the child or an electromechanical device could be used. Also, while a turnstile has been disclosed, it will be recognized that other admission control devices could be used. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed. | Methods for controlling admission to amusement park rides include electronically measuring each child's height (and optionally weight) and comparing the measured data to a database which specifies minimum requirements for each ride in the amusement park. Upon completing the comparison, several optional steps are provided including encoding a data carrier with the child's measured data and/or a list of rides which are appropriate for the child. The data carrier may be a “swipe card” or other machine readable device which must be presented at the entrance to each ride. The entrance to each ride is provided with an electronic entry control gate which is operated by the data carrier. Optionally, a list of appropriate rides is printed for the child and/or the child's parents. Apparatus for performing the methods are also disclosed. | 0 |
BACKGROUND
The present invention relates generally to integrated circuit designs, and more particularly to a static random access memory (SRAM) device with a low operation voltage.
Static random access memory (SRAM) is typically used for the temporary storage of data in a computer system. SRAM retains its memory state without the need of any data refresh operations as long as it is supplied with power. A SRAM device is comprised of an array of “cells,” each of which retains one “bit” of data. A typical SRAM cell may include two cross coupled inverters and two access transistors connecting the inverters to complementary bit-lines. The two access transistors are controlled by word-lines to select the cell for read or write operation. In read operation, the access transistors are switched on to allow the charges retained at storage nodes of the cross coupled inverters to be read via the bit line and its complement. In write operation, the access transistors are switched on and the voltage on the bit line or the complementary bit line is raised to a certain level to flip the memory state of the cell.
FIG. 1 schematically illustrates a typical six-transistor SRAM cell 100 . The SRAM cell 100 is comprised of PMOS transistors 102 and 104 , and NMOS transistors 106 , 108 , 110 and 112 . The PMOS transistor 102 has its source connected to a supply voltage Vcc, and its drain connected to a drain of the NMOS transistor 106 . The PMOS transistor 104 has its source connected to the supply voltage Vcc, and its drain connected to a drain of the NMOS transistor 108 . The sources of the NMOS transistors 106 and 108 are connected together to a complementary supply voltage, such as ground voltage or Vss. The gates of the PMOS transistor 102 and the NMOS transistor 106 are connected together to a storage node 114 , which is further connected to the drains of the PMOS transistor 104 and the NMOS transistor 108 . The gates of the PMOS transistor 104 and the NMOS transistor 108 are connected together to a storage node 116 , which is further connected to the drains of the PMOS transistor 102 and the NMOS transistor 106 . The NMOS transistor 110 connects the storage node 116 to a bit line BL, and the NMOS transistor 112 connects the storage node 114 to a complementary bit line BLB. The gates of the NMOS transistors 110 and 112 are controlled by a word line WL. When the voltage on the word line WL is a logic “1,” the NMOS transistors 110 and 112 are turned on to allow a bit of data to be read from or written into the storage nodes 114 and 116 via the bit line BL and the complementary bit line BLB.
One drawback of the typical six-transistor SRAM cell 100 is that it requires a relatively high operation voltage Vdd, which becomes a bottleneck, for designing new generation SRAMs. As the semiconductor processing technology advances, integrated circuits become smaller in size, and their supply voltage Vcc becomes lower in order to reduce power consumption. However, because the operation voltage Vdd of the conventional SRAM cell 100 has to remain at a certain level, it becomes the bottleneck of the efforts in designing the new generation SRAM with lower supply voltage Vcc.
FIG. 2 illustrates a conventional two-port SRAM cell 200 comprised of PMOS transistors 202 and 204 , and NMOS transistors 206 , 208 , 210 , 212 , 214 , and 216 . In write operation, the NMOS transistors 210 and 212 are turned on for allowing a logic “1” or “0” to be written into the storage nodes 218 and 220 . In read operation, the NMOS transistor 216 is turned on and the read bit line BL is pre-charged to a high voltage. If the voltage at the storage node 218 is high, the NMOS transistor 214 will be turned on and the read bit line BL will be pulled low. If the voltage at the storage node 218 is low, the NMOS transistor 214 will be turned off, and the voltage on the read bit line BL will remain high.
It is understood by those skilled in the art of integrated circuit design that although the operation voltage applied to read word line WL can be set lower than that of the conventional six-transistor SRAM cell, the operation voltage applied to write word line WL cannot be lowered significantly. As such, what is needed is to design a new SRAM cell that can operate with low operation voltage in both read and write operation.
SUMMARY
The present invention discloses a SRAM cell with a relatively low operation voltage. In one embodiment of the present invention, the SRAM cell includes a first PMOS transistor having a source coupled to a supply voltage; a second PMOS transistor having a source coupled to the supply voltage, a drain coupled to a gate of the first PMOS transistor, and a gate coupled to a drain of the first PMOS transistor; a first write switch module coupled between the first PMOS transistor and a complementary supply voltage; a second write switch module coupled between the second PMOS transistor and the complementary supply voltage; and a read switch module coupled between the gate of the first PMOS transistor and a read bit line, wherein the first write switch module, the second write switch module, and the read switch module are controlled separately to write or read a logic value to or from one or more storage nodes at the drains of the first and second PMOS transistors.
The construction and method of operation of the invention, however, together with additional objectives and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a conventional six-transistor SRAM cell.
FIG. 2 schematically illustrates a conventional two-port SRAM cell.
FIG. 3 schematically illustrates an eight-transistor SRAM cell in accordance with one embodiment of the present invention.
FIG. 4 schematically illustrates a ten-transistor SRAM cell in accordance with one embodiment of the present invention.
FIG. 5 illustrates a diagram showing a layout view of various bit lines and word lines of the eight-transistor SRAM cell in accordance with one embodiment of the present invention.
FIG. 6 illustrates a diagram showing a layout view of various bit lines and word lines of the eight-transistor SRAM cell in accordance with another embodiment of the present invention.
FIG. 7 illustrates a diagram showing a layout view of various bit lines and word lines of the ten-transistor SRAM cell in accordance with one embodiment of the present invention.
FIG. 8 illustrates a diagram showing a layout view of various bit lines and word lines of the ten-transistor SRAM cell in accordance with another embodiment of the present invention.
DESCRIPTION
This invention is related to a SRAM device with a relatively low operation voltage. The following merely illustrates various embodiments of the present invention for purposes of explaining the principles thereof. It is understood that those skilled in the art of integrated circuit design will be able to devise various equivalents that, although not explicitly described herein, embody the principles of this invention.
References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure or characteristic, but every embodiment may not necessarily include the particular feature, structure or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to implement such feature, structure or characteristic in connection with other embodiments whether or not explicitly described.
FIG. 3 schematically illustrates an eight-transistor SRAM cell 300 in accordance with one embodiment of the present invention. The SRAM cell 300 is comprised of PMOS transistors 302 and 304 , write switch modules 306 and 308 , and a read switch module 310 . The PMOS transistor 302 has a source coupled to a supply voltage Vcc, and a drain coupled to the write switch module 306 , which is further connected to a complementary supply voltage, such as ground or Vss. The PMOS transistor 304 has a source coupled to the supply voltage Vcc, and a drain coupled to the write switch module 308 , which is further connected to the complementary supply voltage. The gate of the PMOS transistor 302 is coupled to the drain of the PMOS transistor 304 , forming a storage node 310 . The gate of the PMOS transistor 304 is coupled to the drain of the PMOS transistor 302 , forming a storage node 312 .
The write switch module 306 includes NMOS transistors 314 and 316 serially coupled between the node 312 and the complementary supply voltage. The NMOS transistor 314 has a drain coupled to the node 312 , a source coupled to the drain of the NMOS transistor 316 , and a gate coupled to a write bit line BL. The NMOS transistor 316 has a source coupled to the complementary supply voltage, and a gate coupled to a write word line WL. Similarly, the write switch module 308 includes NMOS transistors 318 and 320 serially coupled between the node 310 and the complementary supply voltage. The NMOS transistor 318 has a drain coupled to the node 310 , a source coupled to the drain of the NMOS transistor 320 , and a gate coupled to a complementary write bit line BLB. The NMOS transistor 320 has a source coupled to the complementary supply voltage, and a gate coupled to the write word line WL. The read switch module 310 includes NMOS transistors 322 and 324 serially coupled between the node 310 and the complementary supply voltage. The NMOS transistor 322 has a source coupled to the complementary supply voltage, and a gate coupled to the node 310 . The NMOS transistor 324 has a source coupled to the drain of the NMOS transistor 322 , a drain coupled to a read bit line BL, and a gate coupled to a read word line WL.
In write operation, the NMOS transistor 324 is turned off and the voltage on the write word line WL are raised above a predetermined level to turn on the NMOS transistors 316 and 320 . Depending on whether the node 310 or the node 312 is selected for programming a predetermined logic value, one and only one of the write bit line BL and complementary write bit line BLB is asserted to turn on one and only one of the NMOS transistors 314 and 318 . Supposing the NMOS transistor 314 is turned on and the NMOS transistor 318 is turned off, the node 312 is pulled to the complementary supply voltage, thereby turning the PMOS transistor 304 on. As a result, the node 310 is charged and the node 312 is discharged. At the end of each write cycle, the NMOS transistors 316 and 320 will be turned off, such that the nodes 310 and 312 will remain at their memory states.
In read operation, the NMOS transistors 316 and 320 are turned off, the read BL is pre-charged to a high state, and the voltage on the read word line WL is raised above a predetermined level to turn on the NMOS transistor 324 . If the node 310 is at a high state, the NMOS transistor 322 will be turned on, thereby pulling the read bit line BL to the complementary supply voltage. If the node 310 is at a low state, the NMOS transistor 322 will be turned off, and the voltage on the read bit line BL remains high. By sensing the signals on the read bit line BL, the memory state at node 310 can be determined.
One of the advantages of the proposed SRAM cell structure is that its operation voltage can be significantly lower than that of the conventional SRAM cell. The threshold voltage of the NMOS transistors 314 , 316 , 318 , 320 , 322 and 324 can be designed to be much lower than that of the PMOS transistors 302 and 304 . In this embodiment, the absolute value of the threshold voltage of the NMOS transistor is lower than that of the PMOS transistor by at least 100 mV. As a result, the operation voltage on the write word line WL, write bit line BL, complementary write bit line BLB, and read word line WL can be set at a very low level for both read and write cycles. Thus, the proposed SRAM cell structure can operate with a low operation voltage, thereby reducing its power consumption.
Another advantage of the proposed SRAM cell structure is that the charges retained at the storage nodes 312 and 310 will not be destabilized during a read cycle. As shown in the drawing, the charges are trapped among the gate of the PMOS transistor 302 , the drain of the PMOS transistor 304 , the drain of the NMOS transistor 318 , and the gate of the NMOS transistor 322 . In other words, the charges at the node 310 will not be discharged through the read bit line BL. Thus, they will not be destabilized during a read cycle.
FIG. 4 schematically illustrates an SRAM cell 400 in accordance with one embodiment of the present invention. The major difference between the cell 300 shown in FIG. 3 and the cell 400 is that the cell 400 includes two read switch modules 402 and 404 . The read switch module 402 includes NMOS transistors 406 and 408 serially coupled between the node 410 and the complementary supply voltage. The NMOS transistor 406 has a source coupled to the complementary supply voltage, and a gate coupled to the node 410 . The NMOS transistor 408 has a source coupled to the drain of the NMOS transistor 406 , a drain coupled to a read bit line BL, and a gate coupled to a read word line WL. Similarly, the read switch module 402 includes NMOS transistors 412 and 414 serially coupled between the node 416 and the complementary supply voltage. The NMOS transistor 412 has a source coupled to the complementary supply voltage, and a gate coupled to the node 416 . The NMOS transistor 414 has a source coupled to the drain of the NMOS transistor 412 , a drain coupled to a read bit line BL, and a gate coupled to a read word line WL. Since the memory states at the nodes 410 and 416 are complementary, the signal readings on read bit line BL and complementary read bit line BLB are also complementary.
FIG. 5 illustrates a diagram 500 showing a layout view of various bit lines and word lines of the SRAM cell 300 in FIG. 3 in accordance with one embodiment of the present invention. The write bit line, read bit line, supply voltage line, and complementary write bit line are arranged along the same direction across the pitch of the cell on the same metallization layer. The write word line and read word line are arranged along another direction on another metallization layer. This arrangement can reduce the coupling effect, due to the shortened bit lines, and the shielding effect among those conductive lines.
FIG. 6 illustrates a diagram 600 showing a layout view of various bit lines and word lines of the SRAM cell 300 in FIG. 3 in accordance with another embodiment of the present invention. The write bit line, read bit line, supply voltage line, and complementary write bit line are arranged along the same direction across the pitch of the cell on the same metallization layer. The write word line and read word line are combined as a single conductive line along another direction on another metallization layer. This arrangement can reduce the coupling effect, due to the shortened bit lines, and the shielding effect among those conductive lines.
FIG. 7 illustrates a diagram 700 showing a layout view of various bit lines and word lines of the SRAM cell 400 in FIG. 4 in accordance with one embodiment of the present invention. The write bit line, read bit line, supply voltage line, complementary read bit line, and complementary write bit line are arranged along the same direction across the pitch of the cell on the same metallization layer. The write word line and read word line are arranged along another direction on another metallization layer. This arrangement can reduce the coupling effect, due to the shortened bit lines, and the shielding effect among those conductive lines.
FIG. 8 illustrates a diagram 800 showing a layout view of various bit lines and word lines of the SRAM cell 400 in FIG. 4 in accordance with another embodiment of the present invention. The write bit line, read bit line, supply voltage line, complementary read bit line and complementary write bit line are arranged along the same direction across the pitch of the cell on the same metallization layer. The write word line and read word line are combined as a single conductive line along another direction on another metallization layer. This arrangement can reduce the coupling effect, due to the shortened bit lines, and the shielding effect among those conductive lines.
The above illustration provides many different embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims.
Although the invention is illustrated and described herein as embodied in one or more specific examples, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims. | An SRAM cell includes: a first PMOS transistor having a source coupled to a supply voltage; a second PMOS transistor having a source coupled to the supply voltage, a drain coupled to a gate of the first PMOS transistor, and a gate coupled to a drain of the first PMOS transistor; a first write switch module coupled between the first PMOS transistor and a complementary supply voltage; a second write switch module coupled between the second PMOS transistor and the complementary supply voltage; and a read switch module coupled between the gate of the first PMOS transistor and a read bit line, wherein the first write switch module, the second write switch module, and the read switch module are controlled separately to write or read a logic value to or from one or more storage nodes at the drains of the first and second PMOS transistors. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control apparatus for controlling a work processing operation of a machine tool.
2. Background Art
To standardize sequence programs necessary for work processing operations regardless of the specifications of a machine tool, a conventional machine tool control apparatus is configured to set standard sequence programs (referred to hereinafter as a basic parameter) serving as standards in response to the specifications of the machine tool. Upon running of the unfinished machine tool during the manufacturing stage of the machine tool and also upon temporary running of the machine tool during a failure, part of the basic parameter is temporarily switched, thus running the machine tool based on this temporarily set parameter. (See JP-UM-A-5-33202)
SUMMARY OF THE INVENTION
In reality, there is the problem that the conventional machine tool control apparatus, which temporarily switches part of the basic parameter, has the following risk. That is, after the machine tool is finished and also after the machine tool is recovered from the failure, an operator erroneously run the machine tool without returning the altered temporary parameter to the original basic parameter. Thus, the machine tool performs an erroneous sequence operation, which induces a failure.
The invention has been made to solve the problem consisting in the aforesaid conventional technology. It is an object of the invention to provide a machine tool control apparatus in which after a machine tool is run based on a variable parameter obtained by temporarily altering a basic parameter, the machine tool can be prevented from being erroneously run without returning to the original basic parameter.
To achieve the object, the invention provides a machine tool control apparatus including: a control program storage unit that stores therein control programs for performing standard running control in correspondence with specifications of a machine tool, the control program storage unit being provided with: a basic data memory that sets a control program for performing standard running, and a variable data memory that temporarily alters part of the control program to set a control program for performing temporary running; a parameter check unit that checks whether a basic parameter stored in the basic data memory and a variable parameter stored in the variable data memory are “matched” with each other; and a temporary running confirmation operation unit that enables the standard running when a parameter check result from the parameter check unit is “match” and that enables the temporary running by performing a temporary running confirmation operation while disenabling the standard running when the parameter check result is “mismatch”.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more readily described with reference to the accompanying drawings, in which:
FIG. 1 is a block circuit diagram of a machine tool control apparatus of the invention;
FIG. 2 is an explanatory diagram showing an example of a basic parameter and a variable parameter that are set in response to specifications of a machine tool;
FIG. 3 is a flowchart showing a running operation of the machine tool;
FIG. 4 is a front view showing a screen of data displayed on a CRT display; and
FIG. 5 is a flowchart showing a part of the running operation in detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of a machine tool control apparatus in which the invention is embodied will hereinafter be described in accordance with the drawings.
FIG. 1 is a block circuit diagram of a machine tool control apparatus 11 . A central processing unit (CPU) 12 provided in this control apparatus 11 is connected via a data bus 13 and an I/O interface 14 with a CRT display 15 functioning as a temporary running confirmation display unit. Besides, the CPU 12 is connected via an I/O interface 16 with a keyboard 17 for entering various data, via an I/O interface 18 with various devices (an I/O unit 19 ), and via an NC interface 20 with a numerical control device (NC) 12 for numerically controlling a machine tool. Besides, the control apparatus 11 includes a power supply unit 22 .
The CPU 12 is connected with a readable/writable random access memory (RAM) 23 for storing various data. This RAM 23 pre-stores therein control programs for controlling standard running operations suitable for the specifications of the machine tool. Besides, the RAM 23 includes a parameter storage area 24 functioning as the basic/variable parameter storage units that sets the control programs.
In the embodiment, the CPU 12 , CRT display 15 , keyboard 17 , RAM 23 , parameter storage area 24 , etc. function as a control program storage unit, a parameter check unit, a temporary running confirmation operation unit, and a temporary running confirmation display unit that notifies an operator by displaying that a confirmation operation has been performed by the temporary running confirmation operation unit.
Various data to be stored in the parameter storage area 24 of the RAM 23 will now be described according to FIG. 2 .
The embodiment is configured as follows. That is, any one of three types A, B, and C of running operation modes is selected in response to the corresponding one of three specifications of the machine tool. Thus, various items necessary for running are stored as parameters in correspondence with respective addresses. Besides, the keyboard 17 is operated whereby the parameter storage area 24 has a basic parameter SP pre-set to either “1” or “0”. Furthermore, any one of the individual items is rewritten and stored as a variable parameter CP in correspondence with the basic parameter SP. And, for example, when individual items of the variable parameter CP are set similar to those of the basic parameter SP of A type, the standard running for work processing operation of the machine tool under the A type specification is controlled by the basic parameter SP of A type. Besides, for example, with the basic parameter SP of C type being set, when the same item of the variable parameter CP as that thereof is not selected in the item of the 27 th address in FIG. 2 , i.e., when the variable parameter CP is set to “0”, the basic parameter SP and the variable parameter CP are “mismatched”. In this case, standard running control cannot be effected, but a temporary running confirmation operation to be described later is performed, whereby the temporary running for work processing operation of the machine tool is controlled based on this “mismatched” variable parameter CP.
A machine tool operation controlled using the machine tool control apparatus 11 configured as aforesaid will now be described according to flowcharts of FIGS. 3 and 5 .
In step S 1 of FIG. 3 , the power supply is turned on. Thereafter, in step S 2 , the CPU 12 of the control apparatus 11 determines whether the initialization of the variable parameter CP is normal or not. If YES, then in step S 3 , the CPU 12 checks whether the basic parameter SP and the variable parameter are “matched” with each other or not. If NO, then in step S 4 , “variable parameter mismatch” is displayed on a screen of the CRT display 15 . And, in step S 5 , it is determined whether the variable parameter CP is set or not. If NO, then in step S 6 , the operator determines whether or not collective setting is to be performed so that the variable parameter CP “matches” the basic parameter SP. If YES in this step 6 , then the CPU 12 performs the process of step S 7 in which the contents of the variable parameter CP and those of the basic parameter SP are collectively set to be identical with each other. FIG. 5 shows specific operations in the step 7 . As shown in FIG. 5 , in step 21 , it is determined whether the basic parameter SP should be changed. If YES in the step S 21 , the operation proceeds to step S 22 . In the step S 22 , the basic parameter SP is changed to be identical with the variable parameter CP. If NO in the step S 21 , the variable parameter CP is changed to be identical with with the basic parameter SP in step 23 . After the operation according to the step S 22 or the step S 23 is performed, in step S 24 , it is determined whether the operation should be ended. If Yes in the step S 24 , the power supply is turned off in step 25 , and then the operation is ended. If NO in the step S 24 , then the operation returns to the step S 2 .
On the other hand, if the determination is YES in the step S 2 , then in step S 8 , a variable parameter CP anomaly is displayed on the display 15 . Next, in step S 9 , the contents of the variable parameter CP are individually set, and then the operation returns to the step S 2 . When the determination is NO in the step S 6 , then the operation also proceeds to step S 9 .
Furthermore, if a result of checking the basic parameter SP and the variable parameter CP is “match”, i.e., YES in the step S 3 , then the operation moves to step S 10 such that automatic running of the machine tool is enabled. Then the operation proceeds to step S 11 where the automatic running is performed. After that, in step S 12 , the machine tool is turned off.
Besides, if in the step S 5 the determination is YES, i.e., it is determined that the variable parameter CP is set, then in step S 13 , the operator determines whether the variable parameter may remain thus set or not. If YES, then in step S 14 , the operator determines whether or not the temporary running is to be temporarily performed with the variable parameter CP remaining “mismatched”. If the determination is NO in both the steps S 13 and S 14 , the operation moves to the step S 6 .
If the determination is YES in the step S 14 , then in step S 15 , the operator switches ON a “temporary running confirmation” button 31 displayed on the screen of the display 15 and at the same time switches ON a “YES” button of an execution icon 32 . Thereby, in step S 16 , “temporary running confirmation operation storage” switches ON, and at the same time the button 31 lights up. Thereafter, the conditions capable of automatic running of the machine tool are satisfied in the step S 17 . Furthermore, after the automatic running is performed in step S 18 , when the power supply of the machine tool is turned OFF in step S 19 , then in step S 20 , the “temporary running confirmation operation storage” switches OFF, and its record is erased. At the same time, the button 31 is turned off. And, when the power supply is turned ON again, the operation will start from the top of the step S 1 .
According to the machine tool control apparatus of the embodiment, the following advantages can be obtained.
(1) The embodiment is configured as follows. That is, the basic parameter SP and the variable parameter CP are checked with each other. At the same time, the check result is displayed on the screen of the CRT display 15 . Thus, the operator can confirm whether or not the temporary running may be temporarily performed with the variable parameter CP remaining “mismatched”. Therefore, the operator can be prevented from erroneously running the machine tool without confirming the “mismatch” between the basic parameter SP and the variable parameter CP. Thus, the machine tool can be prevented from breaking down.
(2) The embodiment is configured as follows. That is, the “mismatched” state of the variable parameter CP is erased after the automatic running of the machine tool is ended and the power supply is turned OFF. And, when the power supply is ON, it is rechecked whether the variable parameter CP “mismatch” is present or absent. Therefore, when the next running of the machine tool is performed, the “mismatched” state can be easily confirmed. Accordingly, after restart to run the machine tool, the operator can be prevented from erroneously running the machine tool without confirming the variable parameter CP “mismatch”.
(3) In the embodiment, the operator can confirm the checked result of both parameters by means of the screen functioning as the temporary running confirmation display unit of the CRT display 15 shown in FIG. 4 . Thus, the operator can be prevented from making a confirmation error.
(4) In the embodiment, the check result is displayed on the screen of the CRT display. Therefore, the operator can easily perform the confirmation operation as to whether or not the variable parameter CP “matches” the basic parameter SP.
(5) In the embodiment, the operator can easily make a confirmation by means of the button 31 that is displayed on the CRT display 15 to confirm the variable parameter CP “mismatch”.
Additionally, the embodiment may be modified as follows.
There may is provided parameter check unit that checks whether the basic parameter SP and variable parameter CP stored in the parameter storage area 24 are “matched” with each other or not. And, the invention may be embodied as the control apparatus 11 including notification unit that notifies the operator of a check result from this parameter check unit by means of the screen of the CRT display 15 , a sound from a not-shown speaker, or furthermore a sheet, etc. printed by a printer, etc. Thereby, the operator can easily confirm whether the variable parameter CP is “mismatched”, which can prevent the operator from erroneously running the machine tool.
According to the invention, the parameter check unit checks whether the basic parameter stored in the basic data memory and the variable parameter stored in the variable data memory are “matched” with each other or not. Besides, by the temporary running confirmation operation unit, the standard running is enabled when the checked result of both parameters is “match”, and the temporary running confirmation operation is performed with the standard running disabled when the parameter check result is “mismatch”. Therefore, after the machine tool is temporarily run based on the variable parameter with the basic parameter brought to a temporary halt, the machine tool can be prevented from being erroneously run without returning to the original basic parameter.
According to the invention, the storage of the temporary running confirmation operation based on the “mismatch” is erased when the power supply of the machine tool is ON, and the both parameters are freshly checked the next time the power supply of the machine tool is OFF. Therefore, upon restart of the machine tool, it can be easily determined whether or not the machine tool may be run based on the “mismatched” variable parameter.
According to the invention, the operator can confirm the checked result of the both parameters by means of the temporary running confirmation display unit, which can prevent the operator from making a confirmation error.
According to the invention, the check result is displayed on the screen of the display. Therefore, the operator can easily perform the confirmation operation as to whether or not the variable parameter “matches” the basic parameter.
According to the invention, the operator can easily makes a confirmation by means of the icon that is displayed on the display to confirm the variable parameter “mismatch”. | A machine tool control apparatus includes: a control program storage unit that stores control programs for performing standard running control. The control program storage unit includes a basic data memory that sets a control program for performing standard running, and a variable data memory that temporarily alters part of the control program to set a control program for performing temporary running. The machine tool control apparatus further includes a parameter check unit that checks whether a basic parameter stored in the basic data memory and a variable parameter stored in the variable data memory are “matched”; and a temporary running confirmation operation unit that enables the standard running when a parameter check result from the parameter check unit is “match” and that enables the temporary running by performing a temporary running confirmation operation while disenabling the standard running when the parameter check result is “mismatch”. | 6 |
REFERENCE TO A RELATED APPLICATION
This application is a division of copending application Ser. No. 265,547, filed Nov. 1, 1988, now U.S. Pat. No. 4,969,328, granted Nov. 13, 1990; which was a continuation-in-part of my prior applications Ser. No. 921,330, filed Oct. 21, 1986 and now abandoned and Ser. No. 095,042, filed Sep. 9, 1987 and now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a device for oxidizing certain exhaust emissions from diesel engines, for vehicles or stationary applications.
It is well known that diesel engines emit noxious exhaust by-products which are not only a nuisance to the public, but a health hazard as well. Therefore, complete public acceptance of diesel engines will not occur until the noxious constituents of their exhausts have been substantially cleaned up. The U.S. E.P.A. has established, by regulations, levels for such emissions which are at present considered tolerable, but insofar as the applicant is aware, no one has been able to design a system which can meet them satisfactorily.
This invention relates to a device containing a filter means for connection to a diesel engine to process the exhaust. The device collects soot, and certain particulate emissions, and disposes of them during engine operation either (1) by what is herein called "natural regeneration" when the temperature of the filter is high enough, or else (2) by what is herein called "forced regeneration" when the filter, due to insufficiently high temperatures, becomes loaded with particulates to the pointwhere it either may not function properly or else otherwise interfere with the vehicle's operation. The latter type of regeneration is initiated by an associated electronic control unit which receives signals from various sensing devices associated with the engine and/or with the collecting and oxidizing device itself. In both types of regeneration processes, soot which has been accumulated in the device is burned out and the by-product, carbon dioxide mainly, is disposed of into the atmosphere. The device may be endowed with particular catalyst formulation which also oxidizes hydrocarbons and carbon monoxide thereby substantially reducing, if not essentially entirely eliminating, diesel odor.
The invention comprises a number of features which individually and collectively contribute to its ability to clean up diesel engine exhaust. These features relate to: (1) the sensing of when the device has become loaded to the point where forced regeneration should be initiated; (2) the manner of by-passing the collection and oxidizing zone during forced regeneration; (3) control of the forced regeneration process; (4) the manner in which forced regeneration is performed; (5) the manner in which exhaust is forced to flow through the device; (6) the configuration of the filter; and (7) the overall organization of the device.
The foregoing features are disclosed in a first embodiment of the invention. Also disclosed herein is a second embodiment which contains further features beneficial to soot collection efficiency. They are: 1) a pre-converter for the control of hydrocarbon (HC), carbon monoxide (CO), and volatile portion of the particulates; and 2) an electrostatic augmented arrangement in which the particulates are pre-charged across a corona discharge medium ahead of the filter element.
The foregoing features, advantages, and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode presently contemplated in carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a central longitudinal cross sectional view through a device embodying principles of the invention.
FIG. 2 is a fragmentary view showing additional detail.
FIG. 3 is a block diagram of the associated electronic control.
FIG. 4 is a partial transverse view through FIG. 1 on line 4--4.
FIG. 5 is a partial transverse view through FIG. 1 on line 5--5.
FIG. 6 is a partial transverse view through FIG. 1 on line 6--6.
FIG. 7 is a view similar to FIG. 1 but of a further embodiment containing additional features.
FIG. 8 is an enlarged axial cross section of an element of FIG. 7 by itself.
FIG. 9 is a transverse cross section on lines 9--9 in FIG. 7.
FIG. 10 is a transverse cross section on lines 10--10 in FIG. 7.
FIG. 11 is a central longitudinal cross sectional view through a second embodiment of device embodying principles of the present invention.
FIG. 12 is a transverse cross sectional view taken in the direction of arrows 12--12 in FIG. 11.
FIG. 13 is a transverse cross sectional view taken in the direction of arrows 13--13 in FIG. 11.
FIG. 14 is a cross sectional view taken generally in the direction of arrows 14--14 in FIG. 11.
FIGS. 15 and 16 are block diagrams illustrating microprocessor logic diagrams that can be utilized in control of a diesel engine exhaust oxidizer.
FIG. 17 is an explanatory diagram.
DESCRIPTION OF THE PREFERRED EMBODIMENT
I. General System Description
The overall system 10 comprises an oxidizer unit 12, an electronic control unit 14, and various sensors to pick up input functions such as temperature, engine RPM, injection pump rack position, and back pressure.
A. Oxidizer Unit 12
The oxidizer unit 12 comprises outer and inner concentric shells 16, 18 made of stainless steel and carbon steel construction to resist the harsh and high temperature environment. It has an inlet 20 which connects to the engine exhaust manifold outlet. The exhaust flow (arrow 22) is directed either to a catalyst unit 24 within shell 16 or to a by-pass 26 which forms an annular space between the shells 16, 18.
A butterfly valve 28 is at the entrance to the two flow paths through the unit. The butterfly valve is operated through a vacuum actuator 30 which, in turn, is operated by an electric solenoid switch 32 which controls the vacuum signal 34 according to an electric output control signal received from electronic control unit 14. When the butterfly is in the position shown, flow is through the by-pass; when in the position of the arrows 38, flow is through the catalyst unit 24.
A venturi 36 is installed ahead of the butterfly and by-pass entrance, thus creating a slightly lower pressure at the by-pass entrance when the butterfly valve is in the open position.
The by-pass entrance 40 is normally closed by a spring-biased door 42; the door and mechanism 44 are so designed in relation to the venturi's effect that when the butterfly is open to the filter unit 24, as illustrated, the pressure force on the by-pass door will be maintained almost constant under different engine RPMs and loads. The by-pass door will tend to lift open only when the back pressure due to soot build-up within the unit 24 increases to a threshold point.
The core of the unit is made of a series of guiding vanes 46a through 46j specially designed to provide a uniform distribution of the flow over the surrounding catalyst 48. The series of vanes provides change in flow direction and redistribution which results in lowering flow velocities substantially at the filter thus increasing the particulate collection efficiency of the catalyst. The filter 24 is in the form of an annular block made of super-imposed layers of stainless steel wire mesh as supporting material and stainless steel felt of fine strands. This combination provides adequate support while maintaining the efficiency of collection high. The two superimposed layers are rolled up to form the annular block. The flow direction through the catalyst unit is indicated by arrows 52.
Embedded in the catalyst is a heating unit 54 made of parallel elements 56. The heating unit is used as an igniter to initiate forced regeneration of the unit. In a way it functons similar to a match so that the electric heat input required to initiate and maintain regeneration is low and within the practical load demand of the electrical system of a diesel engine vehicle.
Installed at the outlet end of the annular space 58 surrounding the catalyst block 48 is a thermocouple 60 that is used to monitor the temperature and feed it to electronic control unit 14.
B. Electronic Control Unit (ECU) 14
The electronic control unit is made of various dedicated circuit boards and logic elements. FIG. 3 illustrates the schematic of the unit.
C. Sensors
1. Injection pump rack position sensor 62
A standard magnetic pick-up 62 is used to transform the rack position (representing engine load) to one electric signal for electronic control unit 14.
2. Engine RPM sensor 64
A standard magnetic pick-up is used to transform engine RPM to another electric signal for electronic control unit 14.
3. Back-pressure switch 66
The mechanism 44 associated with by-pass door 42, in turn, operates a photo-electric switch 66. This switch 66 transmits a signal to electronic control unit 14 indicating a loaded trap.
4. Detail of ECU 14
ECU 14 comprises a frequency-to-voltage converter 14a which converts the rpm pulses from sensor 64 into a corresponding voltage. This voltage, along with the rack position voltage from sensor 62, and the by-pass valve position voltage from photo-electric sensor 66, are inputs to a control logic circuit 14b. The control logic is constructed to perform the logical control functions herein described for commanding regeneration under the specified conditions. The control logic 14b has its output connected to comparator and driver circuits 14c which drive the butterfly valve in the manner described herein. There is also an amplifier 14d for amplifying the thermocouple signal and supplying it through circuits 14c for control in the manner described.
II. OPERATION OF SYSTEM
Under normal mode of operation no signal is forwarded to solenoid switch 32 of the vacuum actuator, and butterfly valve 28 is in the normal open position illustrated. The entire flow is directed toward the catalyst where soot trapping takes place in addition to chemical reduction of HC and CO emission dependent on any catalyst which may be used on the filter.
After few hours of operation soot accumulation reaches a point where regeneration must take place to bring the trap back to original condition. Loading of the filter with soot is usually accompanied with increase in back pressure and consequently performance and fuel losses. Unless exhaust temperature under some mode of operation reaches soot ignition temperature and consequently the oxidizer regenerates in a natural mode, a forced regeneration is initiated by the electronic control unit. This is the case always when the filter block is not catalyzed since soot ignition temperature is always higher than exhaust temperature.
A. Forced Regeneration Mode
1. Forced regeneration is requested when back pressure continues to build up until threshhold value is reached, causing by-pass door 42 to be popped open, and the photo-electric switch 66 sends a signal to the ECU for the need for regeneration.
2. Regeneration will not actually start until favorable engine RPM, temperature, and load condition are reached. Usually, this requires exhaust temperature sensed by thermocouple 60 to be above a certain temperature, to reduce heater demand on the electric heating unit 54, engine RPM below a certain value, to reduce throttling effect through the by-pass, and engine load rack position below a certain value, to ensure adequate supply of oxygen. If some of these conditions are not satisfied during a certain time, such as the first 1/2 hour, after a regeneration request has been initiated, regeneration will start anyway. The driver of the vehicle has the option to start regeneration by pushing a switch 70 after an indicator light 72 showing a regeneration request has been turned on.
3. When forced regeneration starts, a second light 74 is lit and the following steps take place:
(a) Butterfly valve 28 closes, and electric heater power is turned on for a specified period of time.
(b) At the end of the above cycle, the power is cut off to the electric heater, and the butterfly valve will start duty cycling on and off every certain number of seconds. The amount of valve closing time is a function of the temperature at the thermocouple. Longer closing time results in lowering temperature due to oxygen starvation. A small leakage in the butterfly valve is created to minimize smoldering of soot and keep slow combustion during prolonged valve closing. The valve opening time is such that the entire volume within catalyst is swept with fresh supply of exhaust (oxygen). This results in increasing the temperature at the catalyst. The duration of valve opening time is modulated by engine RPM. Duty cycling of the butterfly valve is controlled by the signal from the thermocouple, through closed loop operation, and temperature is controlled at desirable level to ensure optimum regeneration thus achieving complete combustion and burnout of all soot accumulated. Also vital in the process is limiting the maximum temperature to certain valve to avoid burnout and destruction of the catalyst which is a universal problem with existing traps today.
(c) The process is terminated when the exhaust temperature continues to drop until a certain value is reached and valve opening frequency increases to a certain level indicating regeneration has been achieved. At this point in time, the ECU terminates the process and the butterfly valve will return to the normal open position.
B. Natural Regeneration Mode
Natural regeneration, sometimes may be referred to as "continuous regeneration", is encountered when exhaust temperature is higher than soot ignition temperature. This may be either a condition that results in continuous normal operation without undue effect on the filter, or depending on trap load, it may result in the generation of excessive heat and temperature which could be destructive to the filter. This condition could arise in cold weather during start up due to high HC and CO emission followed by highway driving or due to engine problems whereby oil consumption is too high.
Thermocouple 60 will sense the exhaust temperature and if the temperature or rate of temperature rise with respect to time exceeds the set limits, the butterfly valve will duty cycle in an on-off mode similar to the foregoing A-3 mode of operation. Through closed loop operation, the temperature at the catalyst is controlled and a limit on the maximum temperture is achieved. The process is terminated in a manner similar to the forced regeneration mode.
III. FEATURES
A. System Design
The overall system design, which is a new breakthrough in the technology of controlling diesel emission by exhaust after-treatment technique, will ensure that problems relating to filter burnout, fire hazards, catalyst durability and useful life are resolved satisfactorily in a manner acceptable to different applications of diesel engines in vehicles or stationary applications. The double wall design will limit fire hazards to a minimum since high-temperatures during regeneration is contained within the inner wall. All these features are contained in a compact design which is suitable for installation in the engine compartment or under the floor in a vehicle.
B. Venturi, by-pass passive feature
The venturi by-pass design provides a passive concept for by-passing the flow. In case of butterfly valve, control unit, or loaded trap malfunction, the by-pass feature will ensure that a flow area exists all the time for the exhaust gases, and this unique design feature will ensure that any malfunction in the active components of the oxidizer system will not interfere with the continuous operation of the vehicle. The applicant acknowledges a drop in performance and some power loss when this condition arises which is desirable to have repaired.
C. Venturi, by-pass as trap loading pickup
The venturi is designed to create a negative pressure at the by-pass opening that is a function of flow speed. The pressure drop across the reactor (clean) creates a positive pressure at the by-pass door. The venturi is designed so that the positive and negative pressure drops compensate each other at all different speeds. The door at the by-pass opening, therefore, will not open until the reactor is loaded with particulate and thus an increase in the positive pressure, which is proportional to the degree of trap loading, will offset the spring load on the door causing the door to open. Through the linkage mechanism, the motion is carried to the electrical switch 66 giving signal to the ECU that the trap is loaded and needs regeneration. This arrangement provides a positive, yet passive, feature of predicting trap loading when compared with human use of pressure transducers and associated problems resulting from soot and moisture accumulation at dead spaces.
D. Regeneration Conrolled Temperature Through ECU
Regeneration controlled temperature through ECU and associated sensors and actuators will result in what can be labeled an ideal regeneration through a well controlled process that has a minimum effect on emission during regeneration. The ECU will ensure that a design temperature is achieved and maintained constant during regeneration thus resulting in clean combusion of soots and reliable regeneration.
E. Embedded Electric Heater
Embedded electric heater within the catalyst, and the use of stainless steel felt will result in soot accumulation all around the electric element and felt nearby. In initiating a forced regeneration, the heat energy required to initiate and maintain a regeneration is a small fraction of heat required by conventional systems in which heat is applied ahead of the catalyst. This is in addition to lowering the heat-up time required to initiate soot ignition due to use of bare wire without sheathing around, thus reducing the thermal inertial effect of the wire (heating time for the wire is reduced to about 15 seconds). In addition, the use of elements without sheathing results in lowering thermal inertia and the time required for the element to reach ignition temperature (typically 15 seconds). The problem of maintaining low thermal inertial and providing electric resistance between the element and the steel felt is achieved by applying thin layer (0.005") of ceramic coating having major constituency of silicon oxide and binding phases of silicates and phosphates. The location of the heating element is such that maximum advantage of predominant modes of heat transfer (convection, radiation) are utilized to the maximum to achieve soot ignition temperature all over the catalyst in the shortest period of time.
F. Guide Vanes
The design of the vanes which is unique in this oxidizer will provide the following advantages: (1) minimum pressure drop, (2) equal flow distribution all over the catalyst, which in turn leads to (3) radial flow through the catalyst with a linear velocity through the catalyst that is a fraction of the linear velocity at the inlet of the oxidizer (a ratio of 1:15 to 1:20). This is in comparison to known designs such as axial flow or radial flow. A lower velocity in the catalyst has the following advantages: (1) high filtration efficiency, (2) low Reynold's Number and low pressure drop, (3) minimum or low blowoff of particulate from the catalyst. This unique feature is achieved in the minimum packaging volume which is almost a must in most applications either in the engine compartment or under the floor.
F. 1. Calculation of Vane Sections
The vane's function is to segment, divert, and change flow direction from axial to radial. The entire cross section of the flow in the axial direction is segmented into ten concentric segments for the ten vane example shown. Each concentric segment has an axial area equal to one-tenth the total axial flow area as shown in the diagram. Consequently, for a diameter D of the inlet 45, diameter D1 for 46a, D2 for 46b, D3 for 46c, D4 for 46d, D5 for 46e, D6 for 46f, D7 for 46g, D8 for 46h, and D9 for 46i, the following relationships exist: ##EQU1## The use of ten concentric segments is intended as an example. The actual number used in any given device will depend on certain factors, the most significant of which is probably the size of the device. A smaller design could have fewer, such as five, or a larger design, more than ten.
G. Sandwiched Catalyst Design
This feature is intended to combine the advantage of wire mesh as structurally stable and supportive material, but is slightly inferior as to collection efficiency and blowoff, and stainless steel felt which has high filtration efficiency and minimum blowoff, but unfortunately also has the possibility of plugging and is structurally unstable. By sandwiching the felt between the wire mesh, it is possible to achieve high filtration. Also, when the felt is loaded with particulate, the wire mesh behind it provides a collection room for soot dendrite that would break off the felt without causing plugging of the trap.
DESCRIPTION OF FIGS. 7-10 EMBODIMENT
FIGS. 7-10 show a further embodiment of the invention designated by the general reference 200. It shares many common features with the FIG. 1 embodiment, and they are identified by like reference numerals. The two major features of embodiment 200 which are not present in the FIG. 1 embodiment are generally described as a pre-converter and an electrostatic augumented converter.
Pre-converter
Particulate emissions generated from diesel engines are broadly divided into two portions: 1) solid carbon molecules; and 2) volatile portions containing hydrocarbon elements. Diesel particulates are defined as the disperse matter collected on a filter at a temperature below 52 degrees C. (Ref.: 40 CFR, Part 86, Sub. B). Hydrocarbons having a dew point above 52 degrees C. will condense when cooled to 52 degrees C. or below. Particulates serve as condensation nuclei and the resultant particulates have significant soluble organic fraction (SOF). SOF condensed may account for 10 to 50% of total hydrocarbons, and constitutes between 1 and 90% of the total particulate materials, dependent on engine type and use of turbocharging.
The device of the present invention contains a trap converter and operates at a temperature that is much higher than 52 degrees C. because it is located in the exhaust system. As such it exhibits rather very little catalytic activity at most. This is due to the non-use of noble metals in the majority of cases and to the build-up of particulates on the surface of the wire mesh which isolates the alumina-coated mesh from the gas stream. The net result is that the device (converter) will be functioning in a mode that is being defined as a "total trap" for solid particulates at the operating temperature of the trap. The volatile portion of the particulates, in gaseous form, will pass through the trap without any entrapment. The converter works in a mode as close to a "pure trap" for solid particulates.
Applications where the SOF is dominant or where higher filtration is needed will require a pre-converter to work essentially on the gaseous portions of HC, CO, and SOF. A pre-converter functions essentially in a manner similar to a catalytic converter on a gasoline engine, but with some differences.
A pre-converter in a diesel exhaust environment must be designed in such a way as to maintain a clean surface with minimum build-up or entrapment of particulates on the surface, while maintaining a good gaseous conversion efficiency. This requirement is essential since build-up of soot particulates on the surface of a catalyst could lead to burn-out of the accumulated soot under certain driving conditions (high temperature followed by oxygen rich exhaust) leading to possible destruction of the catalyst and/or burn-out of the pre-converter.
A pre-converter for a diesel control system is designed on the basis of flow velocity. Above a certain threshhold of flow velocity, particulates that have collected on the pre-converter are blown out and re-entrained in the exhaust flow for capturing in the converter. In a vehicle, the device is designed to have this threshhold velocity occur at low to moderate speeds, for example 25-30 miles per hour.
A diesel engine emission control system comprising a pre-converter and a converter is capable of achieving high filtration efficiency for a broad number of diesel engine applications. The converter traps particulates while the pre-converter oxidizes gaseous and SOF pollutants. In FIG. 7 the pre-converter is designated 202, and is disposed upstream of the converter. For certain engines dependent on exhaust temperature profile, it may be preferable to place the pre-converter downstream of the converter where it functions as a post-converter.
Electrostatic Augmented Converter
Conventional fibrous filters such as used in the converter often are limited in performance and collection efficiency depending on the nature of particulates in the diesel exhaust.
An electrostatic augmented filter as shown in FIGS. 7-10 has considerable improvement in performance, particularly higher collection efficiency (especially for dry particulates normally generated from turbo-charged diesels), and lower pressure drop across the fiber medium.
FIGS. 7-10 show an electrostatic precipitator 204 as an integral part of the converter. It consists of three coaxial perforated screens 206, 208, 210, of successively larger diameter surrounding the vanes. The inner screen is electrically grounded and joins to the perimeters of the vanes. The intermediate screen 208 is electrically insulated from the rest of the converter and is connected to a high voltage terminal 211 which in turn is connected to a high voltage D.C. power supply (not shown). Screen 208 is electrically charged from the power supply and when so charged, serves to pre-charge the radial flow of exhaust gases which pass through its perforations. The high voltage is such that a corona discharge takes place between the screen 208 and the inside surface of the screen 210. Although the screen 208 comprises perforations in the form of circular holes formed by punching material out of the screen, other forms of perforations may be used to advantage. For example, perforations formed by piercing rather than punching create elongated, cylindrical-walled perforations which have free edges toward screen 210 at which the corona discharge occurs. This can result in full ionization of the particulate matter.
The screens 206, 208, 210 are maintained in spaced apart relation by a series of high-voltage insulators 212 at appropriate locations. Since particulates are electrically conductive, insulators are subject to mechanical failure caused by electrical sparking generated from disposition of conductive particulates on the surface. Arc-over results in localized overheating and the associated thermal stress leading to mechanical failures. Another mode of failure which results from arc-over is not necessarily accompanied by stress-induced mechanical failure. Rather, particle deposits may impregnate the insulator at the high temperatures induced by arcing and ultimately lead to permanent short-circuiting of the insulator.
The design of insulators in the device 200 is intended to yield improvements in performance and life expectancy. Details of an insulator are seen in FIG. 8. Basically the insulator, which is of course of a suitable material, comprises a pair of disc-like heads 214, 216, which are at the opposite ends of a cylindrical spacer 218. The insides of the heads comprise concentric circular grooves 220 which constitute air gaps forming stagnant spaces. The intention is to control the path of arcing such that arcing occurs mostly through the air, and in this way the resultant heat is dissipated mostly in the air rather than on the insulator. The surface of the insulator is preferably glazed to minimize surface adhesion of particulates.
The surface area of the insulator along which flow takes place is where soot tends to collect. The inclusion of the air gaps and stagnant spaces breaks down the surface area such that soot collection is minimized, especially in the stagnant spaces. Soot accumulation in the stagnant spaces is very small in comparison to the surfaces more directly exposed to the flow. When arcing occurs, virtually all accumulated soot is cleared at and around the location where arcing occurs. At the air gaps the soot is completely cleared. The arcing also results in substantial clearing of soot at other nearby locations on the insulator. Because the air gaps and stagnant spaces accumulate soot at much slower rates than if the insulators did not possess such features, and because they increase the length of the electrical path, arcing frequency is drastically reduced, and life expectancy is increased.
FIGS. 11-14 show a further embodiment of converter, or diesel emission oxidizer, 300 which has a flatter profile than the preceding embodiments. A flatter profile may be an advantage in certain applications, such as when the converter is mounted horizontally under the floor of the body of a truck or car. The exhaust flow from a diesel engine enters the inlet 302. The exhaust flow is directed either to an electrostatic precipitator/catalyst section 304 or to a bypass 306. A butterfly valve 308 is at the entrance to the two flow paths through the converter. When the butterfly is in the solid line position, flow is to the section 304, but when the butterfly is in the broken line position, flow to section 304 is blocked. When the flow to section 304 is blocked by the butterfly, the entire flow passes through the bypass 306, entering the bypass at the perforations 305 in wall 307. A venturi section 310 is disposed just ahead of the butterfly.
The butterfly is opened and closed by a control (not shown in FIGS. 11-14) which is the same as the control described for the first embodiment. The embodiment of FIGS. 11-14 has no separate bypass door such as the door 42 in FIG. 1. When the butterfly is in the solid line position, the venturi effect creates an acceleration in the flow which will result in the flow passing to the section 304, and not to the bypass. When the butterfly is in the solid line position, flow through the precipitator/catalyst is indicated by the arrows 314. When butterfly 308 is in the broken line position, bypass flow through the converter is indicated by the reference numeral 312.
The precipitator/catalyst section 304 comprises a series of guide vanes 316A, 316B, 316C that are arranged at the bottom to provide a generally uniform upward distribution of the flow through the precipitator/catalyst 304 in the manner indicated by the arrows 314. The vanes provide a change in flow direction and a distribution which results in lowering the flow velocities, thereby increasing the particulate collection efficiency of the catalyst.
The particular number of vanes that are employed will depend upon the specific design and the three vanes shown in the drawing is an arbitrary number. The width, or lateral dimension, of the vanes is substantially equal to the width of the converter's enclosure.
The electrostatic precipitator portion of precipitator/catalyst 304 overlies the vanes and comprises three generally rectangular shaped plates 318 which are spaced apart from each other in a generally parallel manner. The middle plate 318 is supported from the enclosure by means of insulators 320. At least one of the insulators however is constructed with provision to provide for an electrical connection to the middle plate via an electrical terminal such as the terminal 322 indicated in FIG. 14. The other two plates are joined to the enclosure and are therefore grounded. All plates 318 contain perforations to provide for flow through the electrostatic precipitator portion. It is the middle one of the three plates 318 that is connected via terminal 322 to a high voltage DC power supply (not shown), and the electrostatic precipitator operates to precharge the flow of exhaust gasses in the same manner as described in connection with the electrostatic precipitator of FIGS. 7-10.
The catalyst portion of precipitator/catalyst 304 comprises a stainless steel wire mesh 324. One or more ceramic coated electric heating elements 326 passes through and is embedded in the wire mesh 324. A ceramic coating on the electric heating elements 326 provides for, among other functions, electrical insulation between the heating elements and the wire mesh when the heating elements are energized. The application of alumina washcoat to the mesh forms the mesh into a rigid matrix, similar to a cobweb, which has a significant void volume that may be approximately 90%. As a result, contact points between the electric heating elements and the rigidly formed wire mesh are fixed in place for life.
However, as a result of the heating elements' expansion and contraction, and associated raspe effect-friction, gas pulsation, vibration, aging, etc,-, some of the contact points between the mesh and the heating elements may loose their ceramic coatings during the life of the device. This could in turn result in an electrical short circuiting at any such point which would bypass the rest of the heating element as well as resulting in accelerated failure of the heated portion.
Tests that have been performed have shown that if a proper size is selected for the wire mesh that comes in contact with the heating elements, the short circuit problem is self-correcting. Most of the heating currents are on the order of 50 to 80 amps. Stainless wires having hydraulic diameters in the range of 0.15 to 0.25 mm will burn out in 3 to 10 seconds should a short circuit develop, thereafter rendering the short circuit open. Accordingly, in the event of certain ceramic degradation, the provision of wire mesh strands that are below a certain size will ensure self-correction of short circuiting. Since short circuiting will be a rather localized phenomenon wherever it occurs, a relatively minor ceramic degradation will not have any appreciable effect on the performance of the device.
Converter 300 also comprises a dual purpose air injection system. Air injection is a known procedure that has been used in particulate traps for regeneration. It provides adequate oxygen supply that enhances the probability of a successful regeneration. Air injection is also a known procedure that has been used in blowing off aerosol particles accumulating around insulators in electrostatic precipitators, and as such it prevents sparking and mechanical failure of the insulators.
Converter 300 is designed to regenerate under most driving conditions except those associated with high acceleration, load and speed. In most automotive applications sudden change in driving patterns can increase the probability of incomplete regeneration. Although an incomplete regeneration is detected and accounted for and has no impact on operability or emission, the probability of incomplete regenerations may warrant the use of air injection.
Accordingly, in converter 300 injected air from a suitable air supply, such as a pump (not shown) for example, is introduced into section 304. Within converter 300, tubes 332 convey the injected air to the individual insulators. This injected air is used in conjunction with the exhaust flow for the combustion of soot during regeneration and also for maintaining the insulators in a reasonably clean condition.
A further aspect of the invention relates to the reduction of peak temperatures leaving the outlet of the converter during regeneration. The regeneration process is controlled through duty cycling of the butterfly valve in the manner described for FIG. 1. This results in the repeated diverting of the exhaust flow into two segments, namely a flow segment that has passed through precipitator/catalyst 304 followed by a flow segment that has passed through the bypass. Each of these two segments typically has a duration of approximately one to three seconds. Since these segments discharge at the downstream outlet end of the converter, it is possible for segments of high temperature gases to escape from the tailpipe at temperatures close to the regeneration temperature. Such high temperatures, which could reach 1400 degrees F., may pose a fire/safety hazard around the vehicle, particularly at low traffic speeds or in congested areas. This problem is likely to be encountered on some applications where the converter is installed away from the engine and the tailpipe section that is downstream from the converter is short.
This problem can be resolved in a practical fashion by installing a thermal stabilizer downstream from the converter in the outlet 335. FIGS. 11 and 14 show such a thermal stabilizer 334 disposed in the outlet section of the converter. The stabilizer is an insert similar in construction to a preconverter but without catalysts. The insert has a sufficient surface area to enhance thermal conductivity between the hot gases and the insert itself, and it should also have sufficient thermal inertia (weight) to absorb the required amount of heat from a hot gas segment, or column, as that hot gas segment passes through the thermal stabilizer. The heat that is absorbed by the thermal stabilizer is exchanged back to the bypass flow segment, or column, when the cooler bypass flow segment passes through. This process of extracting heat from the flow that has passed through the precipitator/catalyst and then rejecting heat to flow that has passed through the bypass occurs during each cycle of butterfly valve operation. In this way, the thermal stabilizer reduces the peak exhaust gas temperatures at the tailpipe during regeneration. Where the precipitator/catalyst flow gases may be as much as 1400 degrees F. and the bypass flow gases in the range of 300 to 600 degrees F., the thermal stabilizer can reduce the maximum tailpipe temperature to an acceptable level.
While it is expected that a converter system will require maintenance at certain maintenance intervals, the system will not regenerate if it is not maintained and a malfunction develops in any of the active components except for the butterfly valve. Converter 300 is designed such that the pressure drop through a completely soot-laden wire mesh is lower than the pressure drop required to force the exhaust flow through the bypass. If the system is not able to regenerate, it automatically defaults to an agglorometer mode of operation so long as the spring-loaded butterfly valve 308 assumes the solid line (open) position. In this mode of operation, all soot coming into the wire mesh is collected and then subsequently blown off in the form of coarse denderites. Accordingly, the problems associated with particulate emissions entrained in exhaust gases, namely, air pollution, are kept under control; however, the soiling from denderites will remain since these denderites will pass out of the tailpipe and fall on the ground. It is believed that the emission of dendrites is preferable to exhaust-entrained particulates and therefore, the automatic shifting to an agglomerator mode of operation in the event of a failure of any of the active components is deemed desirable.
One of the ways to signal trap loading is to utilize differential pressure transducers before and after the converter and to develop a signal when a predetermined amount of trap loading is sensed. This signal is used to initiate regeneration. Since the transducers are exposed to soot and moisture accumulation, the transducers may malfunction. Moreover, the use of transducers adds to the overall converter cost.
An aspect of the converter that is disclosed herein relates to a method for predicting soot emission based on engine soot mapping data developed from actual test data from actual engines. Consequently the use of pressure transducers to sense trap loading can be eliminated. For a given engine, the amount of soot generated over time by the engine may be approximated by integrating engine RPM (speed) and rack position (load) with respect to time and then comparing this result with known soot mapping data for the particular model of engine. The process may even be refined by incorporating a correction factor which is equivalent to an emission deterioration factor to account for the increase in emission with accumulated mileage. The engine RPM and rack position are sensed by electronic sensors already on the engine. A microcomputer is utilized to perform the integration functions and the comparison with engine soot mapping data.
It is to be appreciated that this method may not precisely predict the actual soot accumulation and hence, it may not be suitable for certain types of traps such as ceramic traps, since the margin of error is beyond the allowable regeneration zone.
In a converter of the type represented by converter 300 characterized by high soot retention capacity for up to 10 or more hours of operation before regeneration is needed, the regeneration allowable operating zone is bounded on one end by a threshhold of incomplete regeneration and on the other end by a threshhold of blow-off. This zone is substantially wide enough to accommodate the variance in predicting trap loading through use of the integration of engine RPM and rack position with respect to time and comparison thereof with engine soot mapping data. FIG. 17 is a diagram showing the regeneration allowable operating zone for both converter 300 and for a typical ceramic trap. The ceramic trap must be regenerated much more frequently and within a smaller allowable zone than converter 300.
FIG. 17 shows two curves a and b. Curve a is symmetric about the design loading, and represents the probability of the accumulated soot measurement being high. Curve b is skewed to the right, and represents the probability of the accumulated soot measurement being high while taking into account systems delays which may occur before actual regeneration starts.
FIG. 15 portrays a logic flow diagram for the operation of a microprocessor that is utilized for control of the regeneration process in converter 300 when the converter is used in a transit bus application. The first step in the process is to compile the level of soot accumulation in the particulate trap by integrating the rack position and RPM as a function of time in the manner previously described. So long as the soot accumulation does not reach a predetermined high level, this compilation continues. When the soot reaches a first predetermined high level, a level 1 warning starts. The probability of arriving at the beginning of a level 1 warning is represented by curve a in FIG. 17. This first warning level is a visual one that is provided by a warning light on the dash panel of the vehicle. If the converter is not regenerated within a certain amount of time, the second level of warning is initiated and this is preferably an audible sound that is given in conjunction with the first warning. The probability of starting regeneration during either a level 1 or a level 2 warning is represented by curve b in FIG. 17. Regeneration may be started either automatically or manually. As explained earlier, this depends upon the particular driving conditions. In the case of a transit bus, it is unlikely that city revenue service will be conducive to regeneration. Therefore regeneration will probably have to be manually initiated when the vehicle has returned to its yard and is idling.
Regeneration initially involves energizing the electric heating elements 326 for a preset time, closing butterfly valve 308 for a preset time, and thereafter duty-cycling the butterfly. The electric heater elements are turned off after a certain amount of energization. During regeneration, temperature data is compiled to determine whether a successful regeneration has occurred. The regeneration temperature is monitored with respect to time to provide an indication of the thermal heating units released during regeneration. If the monitored value equals or exceeds a reference value, regeneration is considered complete in which case the process of compiling soot accumulation in the new cycle can begin anew. That portion of the logic diagram between the block entitled "Close Butterfly Valve For Preset Time" and the block "Terminate Duty Cycle Open Butterfly" (String B of the diagram) involves the duty cycling of the butterfly valve in accordance with the technique described earlier for FIG. 1. It is during the execution of this portion of the cycle that the temperature data is being compiled.
As stated above, a successful regeneration cycle results in beginning to compile soot accumulation information from a starting level in which the initial soot accumulation is considered to be zero. In the event, however, that the compiled temperature data during regeneration indicated that a successful regeneration had not occurred, then it must be assumed that there is a certain amount of unburned soot left in the trap. In such a case, the compilation of soot from the new cycle is in effect, but it begins at a point at which it is assumed that a certain amount of soot exists in the trap due to the fact that not all the soot was burned off during the unsuccessfully completed regeneration. Because of this crediting of unburned soot into the soot accumulation, the next regeneration cycle will start earlier than it otherwise would if there were no credit for the unburned soot. This procedure ensures against encountering blow off in the new cycle.
In certain applications, such as transit bus application, the driving patterns are not conducive to the probability of a successful regeneration while the vehicle is being operated on the road. For this type of application the converter can be designed with a high retention capacity to operate for an extended period of time without regeneration. In this type of a situation, regeneration can be initiated manually by operating the transit bus at idle speed once it has returned to its service facility or service yard.
FIG. 16 illustrates a microprocessor logic diagram for a converter control that is used in truck and automotive type application as distinguished from transit bus type applications. The strings A and B of the logic diagram of FIG. 16 are identical to those of the strings A and B of the logic diagram of FIG. 15 except that in the logic diagram of FIG. 16, regeneration is started automatically. A further similarity in both logic diagrams is that the soot accumulation is compiled by integrating rack position and engine speed with respect to time. When the soot accumulation has reached a predetermined high level which is indicative of a need for regeneration (curve a in FIG. 17), the control then determines whether other conditions are conducive to initiating a regeneration. These conditions are the temperature of the exhaust, the engine load, and the engine speed. So long as the exhaust temperature is sufficiently high and the engine load and speed are not too excessive to ensure adequate oxygen content, then regeneration automatically takes place (curve b in FIG. 17). In other words, regeneration automatically occurs so long as the vehicle is being operated under proper driving conditions. Such proper driving conditions would be those conditions where the engine speed is not excessive and where the engine load is not excessive and where the exhaust temperature is sufficiently high to enhance combustion of the soot. It may happen that proper driving conditions are not reached within the nominal design range of the converter, but a delayed regeneration can still be within the regeneration allowable operating zone. In other words, the typical operation of an automobile or truck is such that there is an extremely high probability that conditions conducive to regeneration will occur within the regeneration allowable operating zone. In the unlikely event of having regeneration beyond the boundaries of the allowable operating zone, no adverse effects are encountered and the deviation will be corrected in the next regeneration cycle. The reason why the above disclosed technique of determining trap loading without transducers can be used is because the soot retaining capacity of the present converters is significantly high when compared to ceramic traps. Hence, although the prediction of trap loading by integrating engine speed and rack position with time may not be as accurate as when using pressure differential transducers, the error margin is well within the regeneration allowable operating zone.
As noted earlier, the converter is designed such that the pressure drop through the wire mesh when completely laden with soot is lower than the pressure drop required to force the flow through the bypass. Hence, when the butterfly is in the solid line position, there is no flow from inlet 302 into the bypass. To the contrary, with a clean trap and even up to the point where the trap becomes completely laden with soot, the flow through section 304 will actually result in a small recirculation through the bypass meaning a small reverse flow through the bypass in a direction opposite arrow 312. The amount of recirculation, of course, progressively decreases as the trap loading increases. With this organization and arrangement then, the bypass door 42 that was present in the version shown in FIG. 1 is unnecessary in converter 300. | An oxidizing device with a microprocessor control means for removing soot and other particulates from the exhaust gases of a diesel engine having an enclosure with a forward inlet for receiving diesel engine exhaust, a main flow path through the enclosure having a medium for trapping soot and other particulates, a bypass through the enclosure for diverting flow from the main flow path, heating elements embedded in the trapping medium, and a microprocessor control means for selectively regenerating the trapping medium in accordance with certain sensed conditions relating to the status of engine operation and the condition of a particulate trapping medium that is disposed in the main flow path. The main flow path has an electrostatic precipitator that is disposed in underlying relationship to the particulate trapping medium in the main flow path and a series of vanes are disposed in underlying relationship to the electrostatic precipitator and serve to redirect the exhaust flow passing through the main flow path and distribute the exhaust flow over the electrostatic precipitator and the trapping medium. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a semiconductor laser device including a semiconductor laser element or a plurality of individual lasers mounted in parallel with a plurality of exit surfaces from which laser light can emerge, which in a first direction has greater divergence than in the second direction which is perpendicular to it, and at least one reflection means which is located spaced apart from the exit surfaces outside of the semiconductor laser element or the individual lasers, with at least one reflecting surface which can reflect back at least parts of the light which has emerged from the semiconductor laser element or the individual lasers through the exit surfaces into the semiconductor laser element or the individual lasers such that the mode spectrum of the semiconductor laser element or of the individual lasers is influenced thereby.
[0002] A semiconductor laser device of the aforementioned type is known from I. Nelson, B. Chann, T. G. Walker, Opt. Lett. 25, 1352 (2000). In the semiconductor laser device described in it, an external resonator is used which uses a grating as the reflection means. Furthermore, in the external resonator directly following the semiconductor laser element is the fast axis collimation lens. Between the fast axis collimation lens and the grating there are two lenses which are used as a telescope. The disadvantage in this semiconductor laser device is that on the one hand due to the many optical components within the external resonator comparatively high losses occur so that the output power of the semiconductor laser device is comparatively low. On the other hand, with the semiconductor laser device known from the prior art only the longitudinal modes of the semiconductor laser element or of the individual emitters of the semiconductor laser element can be influenced. The transverse mode spectrum of the semiconductor laser device cannot be influenced by the structure known from the art. For this reason this semiconductor laser device known from the art per emitter has a host of different transverse modes which all contribute to the laser light emitted from the semiconductor laser device. For this reason the laser light emerging from the semiconductor laser device according to this prior art can only be focussed with difficulty.
[0003] According to the art, an attempt is made to influence the mode spectrum of the semiconductor laser elements by structuring the active zone of the semiconductor laser element. This structuring can includes for example, changes of the refractive index in different directions, so that propagation of individual preferred transverse laser modes is preferred by these refractive indices which change in different directions. Furthermore it is possible, for example by different degrees of doping, to act on the number of electron-hole pairs available for recombination so that at different locations of the active zone different amplifications of the laser light are possible. The two aforementioned methods for giving preference to individual transverse modes are associated with considerable production cost and likewise do not yield actually satisfactory beam quality or output power of the semiconductor laser device.
[0004] An object of this invention is to devise a semiconductor laser device of the initially mentioned type which has high output power with improved beam quality.
SUMMARY OF THE INVENTION
[0005] This is achieved as described in the invention in that at least one reflecting surface of the reflection means is concavely curved.
[0006] In this way, compared to the above described art, additional lenses within the external resonator can be omitted because the concavely curved reflecting surface can be used at the same time as an imaging element. Due to the concave curvature of the reflecting surface in particular the comparatively complex structuring of the semiconductor laser element can be omitted.
[0007] Furthermore, at least one reflecting surface can reflect back the corresponding component beams of the laser light onto the respective exit surfaces such that they are used as an aperture. The mode spectrum of the semiconductor laser element can be influenced with extremely simple means by this measure.
[0008] As in the art, the semiconductor laser device can include a lens means which is located between the reflection means and the semiconductor laser element or the individual emitters and which can at least partially reduce the divergence of the laser light at least in the first direction. This lens means is thus used as the fast axis collimation lens.
[0009] As described in the invention, it is possible for the reflection means to have a reflecting surface on which the component beams emerging from different exit surfaces can be reflected. Alternatively, the reflection means can have a host of reflecting surfaces which can each reflect the component beams emerging from the individual exit surfaces.
[0010] According to one preferred embodiment of this invention, the semiconductor laser device includes a beam transformation unit which is made especially as a beam rotation unit and preferably can rotate individual ones of the component beams at one time, especially by roughly 90°. With such a beam transformation unit the laser light emerging from the semiconductor laser device can be transformed such that it can then be focused more easily.
[0011] According to one preferred embodiment of this invention, the beam transformation unit is located between the reflection means and the semiconductor laser element or the individual lasers, in particular between the reflection means and the lens means. More room for decoupling can be formed by this arrangement of the beam transformation unit within the external resonator.
[0012] The semiconductor laser device can include a frequency-doubling element which is located between the reflection means and the semiconductor laser element or the individual lasers, especially between the reflection means and the lens means. In particular the second harmonic could be decoupled at least partially from the semiconductor laser device and the fundamental wavelength could be reflected back for influencing the mode spectrum at least partially into the semiconductor laser element or the individual lasers.
[0013] As described in the invention, it is furthermore possible for the semiconductor laser element to be exposed to a voltage and to be supplied with current for producing electron-hole pairs only in partial areas which correspond to the three-dimensional extension of the desired mode of the laser light. Giving preference to desired modes of the laser light can be further optimized by this measure which can be carried out relatively easily.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Other features and advantages of this invention become apparent based on the following description of preferred embodiments with reference to the attached figures.
[0015] FIG. 1 shows a schematic top view of a first embodiment of the semiconductor laser device as claimed in the invention;
[0016] FIG. 2 shows a schematic top view of a second embodiment of a semiconductor laser device as claimed in the invention;
[0017] FIG. 3 shows a schematic top view of a third embodiment of a semiconductor laser device as claimed in the invention; and
[0018] FIG. 4 shows a schematic top view of a fourth embodiment of a semiconductor laser device as claimed in the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The embodiment of a semiconductor laser device as described in the invention shown in FIG. 1 includes a semiconductor laser element 1 with a host of exit surfaces 2 , 3 , 4 , 5 from which laser light can emerge. The semiconductor laser element 1 is made as a broad strip emitter array or as a so-called laser diode bar. In the illustrated embodiment, only four exit surfaces 2 , 3 , 4 , 5 which are separated from one another and which are used for light emission are shown. But it is quite possible for there to be a much larger number of exit surfaces which are arranged parallel and spaced apart from one another.
[0020] The laser light emerging from each of the exit surfaces 2 , 3 , 4 , 5 is split into two component beams 2 a , 2 b ; 3 a , 3 b ; 4 a , 4 b ; 5 a , 5 b which each include an oppositely identical angle with the normals to the exit surfaces 2 , 3 , 4 , 5 . The paired component beams 2 a , 2 b ; 3 a , 3 b ; 4 a , 4 b ; 5 a , 5 b each represent a selected laser mode of the emitting component area of the semiconductor laser element 1 which belongs to the corresponding exit surface 2 , 3 , 4 , 5 .
[0021] As FIG. 1 shows, a semiconductor laser device as claimed in the invention furthermore comprises a lens means 6 which is made as a fast axis collimation lens, outside of the semiconductor laser element 1 . The fast axis corresponds to the Y-direction in the illustrated Cartesian coordinate system. The fast axis in these broad strip emitters is the direction perpendicular to the direction in which the individual emitters are located next to one another. The divergence of such a semiconductor laser element 1 in the fast axis is much greater than in the slow axis which is perpendicular to it and which corresponds to the X direction in FIG. 1 .
[0022] Downstream of the lens means 6 at a suitable distance from the semiconductor laser element 1 there is a reflection means 7 with a reflecting surface 8 which faces the semiconductor laser element 1 . The component beams 2 a , 3 a , 4 a , 5 a are reflected back in the direction to the exit surfaces 2 , 3 , 4 , 5 by the reflecting surface 8 . The exit surfaces 2 , 3 , 4 , 5 are optionally provided with a non-reflecting coating so that the component beams 2 a , 3 a , 4 a , 5 a which have been reflected back can penetrate at least partially into the semiconductor laser element 1 such that in this way the mode spectrum of the semiconductor laser element 1 is influenced. In particular, depending on the alignment, focal length and distance of the reflection means 7 , with respect to the exit surfaces 2 , 3 , 4 , 5 preference can be given to the propagation of certain modes in the semiconductor laser element 1 . In the embodiment of a semiconductor laser device as described in the invention shown in FIG. 1 generally not all laser emitters which are assigned to the individual exit surfaces 2 , 3 , 4 , 5 will oscillate at the same mode because the angles at which the illustrated component beams 2 a , 3 a , 4 a , 5 a emerge from the exit surfaces 2 , 3 , 4 , 5 are somewhat different.
[0023] The distance of the reflecting surface 8 from the exit surfaces 2 , 3 , 4 , 5 can be chosen such that it corresponds essentially to the focal length of the reflecting surface 8 . In particular, by the corresponding choice of the distance or focal length, the beam waist on the exit surfaces 2 , 3 , 4 , 5 can correspond roughly to their respective width.
[0024] Decoupling from the semiconductor laser device as shown in FIG. 1 can take place via the component beams 2 b , 3 b , 4 b , 5 b . For example, in FIG. 1 underneath the reflection means 7 another partially reflecting reflection means which is used as a decoupler can be inserted. In addition or alternatively, a beam transformation unit which facilitates further processing of the decoupled component beams could also be placed in the beam path of the component beams 2 b , 3 b , 4 b , 5 b.
[0025] In the embodiment of a semiconductor laser device as described in the invention shown in FIG. 2 , the same parts are provided with the same reference numbers. FIG. 2 shows component beams 2 c , 3 c , 4 c , 5 c which correspond to the transverse mode of the individual emitters of the semiconductor laser element 1 , which emerges from the semiconductor laser element 1 essentially parallel to the normals on the exit surfaces 2 , 3 , 4 , 5 , i.e. roughly in the Z-direction according to a Cartesian coordinate system. The reflection means 9 which is provided in FIG. 2 has not only a reflecting surface, but a host of reflecting surfaces 10 , 11 , 12 , 13 . Thus one of the reflecting surfaces 10 , 11 , 12 , 13 is assigned to each of the component beams 2 c , 3 c , 4 c , 5 c so that in this embodiment each of the emitters of the semiconductor laser element 1 which correspond to the exit surfaces 2 , 3 , 4 , 5 can be operated in the same transverse or longitudinal mode.
[0026] For giving preference to an individual longitudinal mode a wave-selective element 14 which can be made for example as an etalon is shown by the broken line in FIG. 2 . The optional wave-selective element 14 makes it possible to choose certain longitudinal modes, especially a longitudinal mode so that the emitted laser light has a small spectral width.
[0027] Decoupling from the semiconductor laser device can be achieved either by the reflection means 9 being made partially reflective so that in the positive Z direction laser light can emerge from the reflection means 9 . Alternatively, the side of the semiconductor laser element which is facing away from the external resonator which is formed by the reflection means 9 can be partially non-reflective or may not be highly reflective so that on the left side in FIG. 2 of the semiconductor laser element laser light can emerge into the negative Z direction.
[0028] According to another alternative, in FIG. 2 to the left of the semiconductor laser element 1 it is possible for there to be another reflection means which is equivalent to the reflection means 9 and which can reflect back the laser light emerging from the semiconductor laser element 1 in the negative Z direction into the semiconductor laser element 1 . The external resonator in this case is formed by the two reflection means 9 with reflecting surfaces facing one another. One of the reflection means 9 can thus be made partially reflecting so that the laser light can pass through this reflection means partially for decoupling.
[0029] FIG. 2 furthermore shows by a broken line on the right side of the reflection means a beam transformation unit 15 ; it can transform the beam when light emerges in the positive Z direction from the reflection means 9 . The beam transformation unit can be for example a beam rotation unit which can turn each of the component beams 2 c , 3 c , 4 c , 5 c individually by for example 90°. The focussing capacity of the emerging laser light is improved by this beam transformation. As described in the invention it is quite possible to use such a beam transformation unit in the embodiment as shown in FIG. 1 as well.
[0030] The semiconductor laser device as shown in FIG. 3 differs from the one in FIG. 2 essentially in that the modes are preferred which according to FIG. 1 emerge at an angle to the normal from the exit surfaces 2 , 3 , 4 , 5 . The reflection means 16 which is provided in the semiconductor laser device as shown in FIG. 3 in turn has a host of reflecting surfaces 17 , 18 , 19 , 20 . In the embodiment of the reflection means 16 which is drawn using solid lines it is oriented essentially parallel to the X direction so that the paths of the individual component beams 2 a , 3 a , 4 a , 5 a between the exit surfaces 2 , 3 , 4 , 5 and the reflecting surfaces 17 , 18 , 19 , 20 are the same. Alternatively, there can also be a reflection means 16 ′ which is shown in FIG. 3 by the dot-dash line and which can be installed in the semiconductor laser device at the same place as the reflection means 16 . For such a reflection means 16 ′ which is aligned essentially perpendicular to the direction of propagation of the component beams 2 a , 3 a , 4 a , 5 a , the optical paths of the component beams 2 a , 3 a , 4 a , 5 a between the exit surfaces 2 , 3 , 4 , 5 and the reflection means 16 ′ are different.
[0031] In the reflection means 16 the individual reflecting surfaces 17 , 18 , 19 , 20 are tilted relative to the Z-axis. This is omitted in the reflection means 16 ′. In any case it can be necessary here to make the radii of curvature of the reflecting surfaces different from one another.
[0032] FIG. 3 likewise shows a beam transformation unit 15 which is located in the beams 2 b , 3 b , 4 b , 5 b which are to be decoupled. The laser light passing through this beam transformation unit 15 can be focussed for example by other focussing means onto the end of a glass fiber.
[0033] As described in the invention it is possible to provide a wavelength-selective element in the embodiments as shown in FIG. 1 and FIG. 3 . For the differently tilted component beams as shown in FIG. 1 this could necessitate a curved etalon in order to select the same wavelength each time.
[0034] It is furthermore possible as described in the invention to place a beam transformation unit in the external resonator, i.e. between the respective reflection means 7 , 9 , 16 , 16 ′ and the semiconductor laser element 1 , especially between the lens means 6 and the reflection means 7 , 9 , 16 , 16 ′. This arrangement under certain circumstances can entail the advantage that in this way more space is formed for decoupling.
[0035] A beam transformation unit which is made for example as a beam rotation unit rotates the emission of the individual emitters by 90°. After this rotation, the component beams 2 a , 3 a , 4 a , 5 a run at the same angles to the X-Z plane upward and the component beams 2 b , 3 b , 4 b , 5 b run downward at oppositely identical angles. An individual cylindrical mirror is then suited for slow axis collimation. When spherical mirrors are to be used, a mirror array is furthermore needed for slow axis collimation in this case.
[0036] If a stack of emitter arrays is used, in a structure with a beam rotation unit a one-dimensional array of cylinder mirrors for slow axis collimation could be used.
[0037] It is furthermore possible as described in the invention to house a frequency-doubling element, for example a frequency-doubling crystal, in the external resonator. For example, this element could be housed between the lens means 6 and the reflection means 9 in FIG. 2 . In this case the reflecting surfaces 10 , 11 , 12 , 13 can be highly reflective for the fundamental wavelength and permeable to the wavelength of the second harmonic. Under certain circumstances the lens means 6 could also be made such that the fundamental wavelength is transmitted unhindered and the second harmonic is reflected so that the second harmonic is not coupled back into the semiconductor laser element 1 .
[0038] It is possible as described in the invention to use a stack of emitter arrays as the semiconductor laser element 1 . In this case for example a two-dimensional array of spherical or cylindrical mirrors or a one-dimensional array of spherical mirrors can be used. Here the distance and the focal length can be determined according to the statements regarding FIG. 1 .
[0039] It is furthermore possible to use a host of separate individual lasers mounted in parallel instead of a semiconductor laser element 1 which is made as a laser diode bar. They could be operated as single mode lasers and could be triggered individually. This host of individual lasers is especially suited for applications in medical technology.
[0040] FIG. 4 shows a semiconductor laser element 21 which is made as a laser diode bar. The semiconductor laser element 21 has a host of exit surfaces 22 , 23 , 24 from which laser light 25 , 26 , 27 can emerge. Furthermore, in the embodiment as shown in FIG. 4 there is a reflection means 28 which has a host of reflecting surfaces 29 , 30 , 31 which are located next to one another and which for example are made like the reflecting surface 10 , 11 , 12 , 13 as shown in FIG. 2 . Like in the embodiment as shown in FIG. 2 the reflecting surfaces 29 , 30 , 31 reflect back the corresponding portion of the laser light 25 , 26 , 27 through the pertinent exit surfaces 22 , 23 , 24 into the semiconductor laser element 21 . In the selected mode of the laser light shown in FIG. 4 each of the reflecting surfaces 29 , 30 , 31 reflects back the component beams of the respective laser light 25 , 26 , 27 into the semiconductor laser element 21 such that they are reflected at an angle to the normal on the opposite end surface 32 of the semiconductor laser element so that they emerge after this reflection from the adjacent exit surface 22 , 23 , 24 . In this way it becomes possible for essentially a single mode of the laser light to be formed in the overall semiconductor laser element 21 .
[0041] For example, it can also be provided that individual exit surfaces, such as for example the exit surface 23 which is the middle one in FIG. 4 , be provided with a highly reflecting coating 33 so that light from the semiconductor laser element cannot emerge from this exit surface 23 . The light in this case is reflected on this exit surface and after further reflection on the opposing end surface 32 emerges through one of the adjacent exit surfaces 22 , 24 from the semiconductor laser element 21 .
[0042] In the embodiment as shown in FIG. 4 , it can be provided that only certain partial areas 34 of the semiconductor laser element 21 are provided with electrodes so that only these partial areas 34 are exposed to a voltage and thus current is supplied only in these partial areas 34 to produce electron-hole pairs. FIG. 4 furthermore shows partial areas 35 which are not provided with electrodes and accordingly cannot be supplied with voltage either. This configuration optimizes the execution of one or more preferred modes. It is possible to place a lens means which is not shown in FIG. 4 between the reflection means 28 and the semiconductor laser element 21 . | The invention relates to a semiconductor laser devcie, including a semiconductor laser element, or a number of individual lasers mounted parallel to each other, with a number of output surfaces, from which laser light can escape, having a treater divergence in a first direction (Y) than in a second direction parallel to the above and at least one reflecting means, at a distance from the output surfaces, outside the semiconductor laser element or the individual laser, with at least one reflective surface which reflects at least a part of the laser light escaping from the semiconductor laser element or the individual lasers through the output surfaces back into the semiconductor laser element or the individual lasers, such that the mode spectrum of the semiconductor laser element or the individual lasers is influenced. The at least one reflective surface of the reflecting means has a concave curve. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to co-pending U.S. Provisional Patent Application Ser. No. 60/670,220, filed Apr. 11, 2005, the entire contents of which are specifically incorporated herein by reference.
BACKGROUND
[0002] Brake pads are made of a compressed combination of metal, plastic asbestos and other compounds designed to be effective at elevated operating temperatures, while also resisting excessive wear. While such technology is effective for braking and provides a more easily serviceable brake configuration, the advent of the disc brake has culminated in an ongoing aesthetic problem.
[0003] The problem is most visible with regard to inclusion of disc brakes and alloy wheels in the same design. The aesthetic problem occurs as the dust from the brake pads deposits on the alloy wheels. The dust is a combination of carbon fibers, metal filings and polymer adhesives. Because the dust contains adhesive residue, the dust leaves a fine gray, brown and black film on the surface of the alloy wheels. In a matter of days, the film degrades the appearance of the alloy wheels. Further, the film is often not easily removed, resulting in headache for the vehicle owner.
[0004] Where the film is not periodically removed, the acidic content in the film also can etch into the finish of alloy wheels. Thus, the problem presented by brake dust goes further than mere aesthetics.
[0005] Significant efforts have been underway to solve this problem. Primarily, the industry has produced brake pads or disc brake materials formulated to reduce the amount of dust produced. Automobile owners often switch to Kevlar or carbon Kevlar pads, which produce somewhat less dust. While producing less dust, these pads are typically somewhat harder on the rotor.
[0006] The only other option has heretofore been installing a disc of metal or plastic against the inside surface of the wheel. The disc seals the brake area from the wheel and stops the brake dust from depositing on the wheel.
[0007] However, the aesthetics of this design are generally not acceptable, since the disc is visible through the wheel and since the brake calipers and rotors are obstructed from view. Car owners prefer the look of the brake calipers and rotors behind the alloy wheel. Further, the disc hinders airflow through the alloy wheel spokes and may result in deficient brake cooling resulting in fade and rotor warping.
[0008] What is needed in the art is an alternate, aesthetically pleasing mechanism for managing the problem presented by brake dust deposited on wheel surfaces.
SUMMARY
[0009] The above discussed and other problems and deficiencies of the prior art are overcome and alleviated by the presently described brake pad dust collector or diverter, which includes a brake caliper extension operatively associated with the brake pad, the extension shaped and configured so as to divert and/or collect brake dust.
[0010] In one embodiment, the extension is shaped or configured to provide at least one airflow path, such airflow generated by the rotation of a wheel and rotor and directed by said extension of said caliper, the airflow path directed over an edge of the rotor and away from the wheel surfaces.
[0011] In another embodiment, the extension is configured with a cavity having a construction effective to trap brake dust. Such cavity may have a high surface area, e.g., created by a convoluted surface. The surfaces of the extension may also be prepared to adhere dust, e.g., as by including one or more replaceable filters.
[0012] The above-discussed and other features and advantages of the presently described brake pad dust diverter or collector will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Referring now to the drawings, wherein like elements are numbered alike in the several FIGURES:
[0014] FIG. 1 is a side view of an exemplary brake pad dust diverter or collector; and
[0015] FIG. 2 is a front view of an exemplary brake pad dust diverter or collector.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0016] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings.
[0017] With reference to FIG. 1 , the presently described brake pad dust diverter or collector, illustrated generally at 10 , comprises at least one caliper extension 12 operatively associated with caliper portion 14 , which holds a brake pad 16 against a rotor 18 . For purposes of illustration and discussion, extension 12 is illustrated in a “forward” position, that is, forward along a first rotational direction A relative to brake pad 16 (which rotation effects forward movement of the automobile). It should be noted that an extension may, in any instance, be positioned in a “rearward” position in addition to, or in lieu of the “forward” position.
[0018] While the extension 12 may be bolted on, snapped on, adhered on (e.g., as with a high temperature adhesive tape) or the equivalent, the illustrated exemplary embodiment of FIG. 1 shows a snap on configuration, wherein the material of the extension 12 may deflect sufficiently such that an arm 20 thereof slides over a pin 22 on the caliper, which engages a hole 24 in the arm 20 . It should also be noted that while extension 12 is illustrated as a removable piece relative to the caliper, extension 12 may also be a non-removable piece or contiguous portion of the caliper.
[0019] Referring still to FIG. 1 , as illustrated in the exemplary embodiment, the extension 12 may extend at least partially beyond the circumference of the rotor 18 . An interior surface of the extension (not shown) may be angled or otherwise oriented to facilitate directing of airflow caused by rotation of the wheel and rotor (relative to the largely stationary caliper and extension).
[0020] Additionally, with reference to FIG. 2 , at least one interior airflow channel 26 or port 28 may be provided to direct airflow along a path (e.g., along airflow path B) or away from the wheel surfaces 30 . The rotor 18 may also be vented (see vents 32 ) or otherwise apertured or contoured adjacent such extension to further facilitate airflow.
[0021] While an airflow path may be created by virtue of the orientation and/or the configuration of the extension 12 , the extension may also incorporate a dust collection mechanism, such as a filter, a pad, a convoluted surface or cavity, or the like. Additionally, the surface of the extension could be prepared to adhere brake dust. Reference is made to FIG. 1 , which illustrates exemplary positioning of a filter or pad 34 .
[0022] The materials of the extension may be any convenient material, including but not limited to a fiber filled high temperature plastic, a metal, or any other durable material. Where a filter or pad is included, such may be removable (e.g., a removable filter cartridge) for replacement or cleaning.
[0023] Additionally, where the extension 12 is not integral with or permanently adhered to the caliper, the extension 12 may be attached in such a way so as to permit relatively facile removal and cleaning.
[0024] It will be apparent to those skilled in the art that, while exemplary embodiments have been shown and described, various modifications and variations can be made to the embodiments disclosed herein without departing from the spirit or scope of the invention. Accordingly, it is to be understood that the various embodiments have been described by way of illustration and not limitation. | A brake pad dust collector or diverter is described, which includes a brake caliper extension operatively associated with the brake pad, the extension shaped or configured so as to divert and/or collect brake dust. | 5 |
CROSS-REFERENCE
This is a division of application Ser. No. 11/114,703, filed on Apr. 26, 2005 now U.S. Pat. No. 7,170,038, of Kurt Bulter., MOLDING COMPOUNDS FOR USE IN INDUCTION HEATING APPLICATIONS AND HEATING ELEMENTS MOLDED FROM THESE COMPOUNDS which claims benefit to U.S. Provisional Application 60/565,660 filed on Apr. 27, 2004, and application Ser. No. 11/114,703, filed Apr. 26, 2005.
FIELD OF INVENTION
The field of invention is molding compounds that are particularly suitable to be molded into an article that will produce heat and not burn when an electric current is passed through the article. These articles include applications in HVAC, seating, inductance heating and anti-fouling applications. These could include, but not be limited to items such as blower housings, stadium style seating, heated floors and wall and ceiling panels, ice guard, and low conductivity surfaces to inhibit barnacle growth or other undesired parasites. These compounds are generally liquid thermosetting molding resins typically characterized as bulk molding compositions (“BMC”), sheet molding compositions (“SMC”), and/or thick molding compositions (“TMC”). They can be used in molding processes such as compression, transfer, injection/compression molding and injection molding.
Products molded from the composition of this invention desirably have a resistance in the range of 1 to 10 ohms and preferably 1.5 to 7 ohms and more preferably 3.0 to 4.0 ohms when tested as 6″×6″ by 0.125 “panels” as described herein and they achieve this resistance while maintaining flame retardance, preferably achieving a passable flame retardance value when tested in accordance with UL test # 94 V0 and 94 5V tested to a thickness of 0.060 inch. They also have adequate glass transition temperatures and desirable surface characteristics; heat, low temperature, corrosion and shrink resistance; low odor, sound damping strength; and cost. Desirably the compositions include a thermoset resin matrix such as a terephthalate polyester which can include blends of polyester and/or vinyl ester with a significant loading of conductive inorganic filler, typically graphite and optimally blends of graphites. The compositions also include flame and sound retardant additives, and glass fibers. They are further formulated to meet the desired molding characteristics; to withstand the operating temperatures to which they will be exposed; and to have a predetermined strength and a desirable user interface including appearance, and odor. Typically, the compounds will have a glass transition temperature from about 320° F. (160° C.) to about 343° F. (173° C.).
The molding compositions in accordance with the invention can be formed into articles having complex configurations, including configurations with fluid curving lines and further which include integrally molded functional elements, such as rims, flanges, bosses, male and female mating parts. These articles can be relatively large and have the mechanical strength even at elevated temperatures to be self-supporting and to support other elements depending on the application. They also can incorporate the resistive heating quality into the molded article.
The invention also relates to articles which are molded from the previously described compounds. These molded articles include, but are not limited to combination heater/blower housings, air handlers, heating surfaces, ice guard, flooring, seating, and boat and dock surfaces.
BACKGROUND OF THE INVENTION
The present invention recognizes the manufacturing efficiency of molding complex parts from conductive polymeric compositions which can be subjected to a current to induce inductive heating or a mild current, and which are safe to use for these applications by virtue of the fact that they will not burn at the desired thickness. These compounds either replace metal structures that have typically been used for these applications and which require numerous bending, forming and machining processes, or even present the opportunity to develop new articles. For example, in the past, furnaces and air handlers have included a heater which runs in the vicinity of 1000° F. (538° C.), and a blower which expels the heated air from the heater. The housing for the blower has been formed from sheet metal. It typically has curving side walls joined at right angles to planar front and back walls. Thus, it requires complex fabrication steps to produce it. The present invention relates to a combination blower housing and heater. These functions are combined in a conductive molded blower housing that will generate heat in response to a low current. This blower can operate as the blower and heater and can maintain the same thermal efficiency while operating at temperatures ranging from about 250° F. (121° C.) to about 400° F. (204° C.), and more preferably in the range of from about 300° F. (149° C.) to about 350° F. (177° C.). These blower housings can reduce the height and width requirement by about two to about five inches for air handlers and thus have wider applications, including apartment and multiple residence dwellings. They are also useful in commercial heating applications. They have suitable strength, temperature and aesthetic characteristics to allow them to replace metal in known applications in the HVAC and other market areas. The housing can include surface perturbations such as ripples, grooves, or ribs, in the air flow channel which increase heat transfer and thereby improve the thermal efficiency of the furnace or air handler. The heating elements and connecting electrodes can be molded into the housing, further reducing fabrication steps.
There are further applications for these conductive molding compounds in providing alternatives to traditional conductive materials, which often involve greater labor expense to manufacture into complex parts. In particular, in instances where the demand justifies significant volumes of a product, polymer-molding expenses may prove far more cost effective than comparable machining and fabricating expenses for metal materials. However it is not a trivial task to achieve the desired level of conductivity, desirable molding characteristics and the critical safety requirements in one material. Generally, significant weight percentages of an appropriate filler in a polymeric matrix are necessary to achieve satisfactory levels of conductivity and for many applications and resins reinforcement, such as fiber, may be necessary to achieve the desired strength and corrosion resistance over the desired temperature range. However, these high load levels lead to problems with the strength, durability, and moldability and sound resistance of the resulting composition
One area in particular where it would be beneficial to solve the previously mentioned strength, durability, and molding issues is for application in heating and air conditioning, as has been previously discussed. Additional heating applications include heated wall panels, ceiling panels, roofing underlayment, flooring and seating. For example, inductive heating is currently used for flooring in which a conductive mat is used under a ceramic tile floor. While ceramic tile may be beautiful, it is hard, and expensive. It is particularly expensive to install the previously described inductive heating means for large floor surfaces. The current invention would allow the mat to be made from sheet material that could be laid under tile, or could even be constructed directly into the floor as a sheet or as tile, with all of the advantages of a polymeric floor surface. Similarly, wall panels or ceiling panels could combine building functionality with the benefits of heating.
Another area that could benefit from the present invention is heated seating, such a stadium seating, or other outdoor applications, such as ski lifts. Bench seating can incorporate the heating sheet, or the composition can be molded into a contoured seat. In addition, the compounds could be useful for applications in which a mild current is desirable, such as for anti-fouling. The compounds could be molded into plates that are used on boat hulls, or docks to discourage barnacle growth, or could be incorporated directly into the hull or dock. Similarly, the material could be used to discourage birds from roosting on ledges if the material is used to induce a magnetic current.
SUMMARY OF THE INVENTION
The present invention provides conductive molding compositions that meet the safety, strength, and aesthetic requirements to allow for use in inductive and mildly to moderately conductive molded articles. These compounds are typically liquid thermoset resins with a moderate level of graphite or graphite blend to provide the desired conductivity. Additional additives include initiators, flame retardants, and reinforcing fillers and molding agents characteristics to permit the compositions to be molded into the desired shape by a variety of types of molding processes. Optimally, the base resin can include a polyester resin and more specifically can be a terephthalate polyester blended with a epoxy novalac vinyl ester and a loading of graphite of from about 10 to about 80%, and more desirably from about 20 to about 50%, and in particular about 35% to 45% by weight loading of graphite.
In particular, the formulations involve the use of a resin matrix with significant loadings of a conductive filler; various additional additives, such as flame retardants, sound dampeners, initiators, inhibitors, mold-release agents, shrink control additives, fiber reinforcement, viscosity agents, flow modifiers, thickeners, styrene, and carbon black or pigments or other desirable additives. The conductive filler is an inorganic filler which is desirably particulate graphite which is a blend. Conductive polymers may be used as a conductivity enhancer with the graphite. In addition depending on the application, silver coated ceramic fibers can be added to improve the overall electrical properties.
It is anticipated that properties such as the moldablity, coefficient of thermal expansion, electrical and thermal conductivity, shrink resistance and mechanical properties will be in the desired ranges as a result of the use of the present invention.
The foregoing improvements in specimens molded from these compositions enable the low cost mass production of articles used in the heating and surface low conductivity areas, and further allow for the combination of functions in a single article.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a furnace incorporating a heater/blower housing that can be made in accordance with the present invention;
FIG. 2 is an illustration of the heater/blower housing of FIG. 1 ;
FIG. 3 is a graph of the sound speed versus temperature for a composition having loadings of glass fiber ranging between 8% and 23%;
FIG. 4 is a similar graph comparing conductive and non-conductive compounds;
FIG. 5 is a graph showing the conductance of conductive and non-conductive media for test plaques;
FIG. 6 is a graph showing the conductance for actual housing molded from conductive and non-conductive housings;
FIG. 7 is a thermal picture of an actual heater/blower housing molded using a compound in accordance with the present invention; and
FIG. 8 is a SMC machine which can be used which to compound the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention relates to improvements to conductive molding compositions for use in inductive heating and surface low conductivity applications, and to the articles that are made from these compositions. In particular, the compositions can be used in injection molding processes, in transfer molding, in compression molding processes, and in injection/compression molding processes. These processes are cost effective because they eliminate labor intensive machining, and because of repeatability with respect to shot to shot molding. The processes further have better ability to control shot to shot cross parting line thickness. Further these molding processes enable the production of complex configurations that have integral functional features and that have significant concentrations of fillers including conductive filler and fiber reinforcement.
FIG. 1 shows a typical hot air furnace 10 of the prior art. This furnace includes the blower 13 is mounted within a housing 12 that supports the blower motor, and directs the air in the furnace cabinet 14 . The air is directed over the heating coils 16 that can reach temperatures up to about 1,000° F. FIG. 2 shows a side view of the blower housing 12 which is shown as including the motor 13 and various integral mounting features, such as reinforcing ribs 15 , and mounting flanges 17 . In accordance with the present invention, the blower would be conductive, in order that a mild current could be applied to cause a resistance and induce heating in the blower itself. Thus, the need for the heating coils 16 would be entirely eliminated making the furnace much more cost efficient, and smaller.
Sheet molding and bulk molding compositions are described in U.S. Pat. Nos. 5,998,510; 5,342,554; 5,854,317; 5,744,816; and 5,268,400; all of which are hereby incorporated by reference for their teachings on the various modifications to molding compositions that are known to the art.
One component of the molding resin composition is a cross linkable prepolymer such as an unsaturated polyester resin or vinyl ester resin. Desirably the prepolymer has a relatively low molecular weight such as from about 200 to about 5000 (weight average) and a glass transition temperature from about 320° F. (160° C.) to about 343° F. (173° C.). They are described in detail with examples in the above patents incorporated by reference. The polyester resins are the condensation product derived from the condensation of unsaturated polybasic acids and/or anhydrides with polyols such as dihydroxy or trihydroxy compounds. Desirably, these polyester resins are the esterification reaction product of diacids, or anhydrides of diacids, generally having from about 3 to about 12, or more preferably from about 4 to about 8 carbon atoms, with a polyol or a cyclic ether having from about 2 to about 12, or more preferably from about 2 to about 6 carbon atoms.
In general, the vinyl ester resins that can be used are the reaction products of epoxy resins and a monofunctional ethlenically unsaturated carboxylic acid. More specifically, these vinyl ester resins are the reaction product of an epoxy terminated oligomer, for example, an epoxy functionalized bisphenol A with an acrylic acid, or methacrylic acid forming acrylic terminal groups on the oligomer. The vinyl esters have predominantly terminal unsaturation while the unsaturated polyesters have predominantly internal unsaturation.
Another component of the molding composition is one or more unsaturated monomer that is copolymerizable with the resin. Desirably, this component is capable of dissolving the resin component at room temperature. Thus, in one embodiment the resin is dissolved in the monomeric component prior to being combined with the remaining components. Examples of suitable monomers are styrene, alpha-methyl styrene, chloro-styrene, vinyl toluene, divinyl benzene, diallylphthalate, methyl methacrylate, and mixture of these, with preferred monomers being styrene and methyl methacrylate. The ratio of monomer(s) to resin is desirably from about 5:95 to about 50:50 and preferably from about 10:90 to about 25:75 by weight.
Another component to the molding composition is fillers. In accordance with the invention the predominant filler is a conductive filler in order to impart electrical conductivity of the final molded product. A preferred filler is graphite particles. Suitable graphite particles include both natural and synthetic graphite.
Particles are typically measured in microns at some diameter, or also by mesh size wherein a suitable mesh here is typically mostly smaller than about 60 mesh. In addition, silver coated ceramic fibers can be added to improve the overall electrical properties.
In particular, a synthetic crystalline graphite particle, such as currently supplied by applied Carbon of New Jersey under the trademark K100 and K112. The first is characterized as having 0.7 at 40 mesh (420 microns), 22% at 50 mesh (297 microns), 22% at 60 mesh (250 microns), 19% at 70 mesh (210 microns), 16% at 80 mesh (177 microns), 17% at 100 mesh (149 microns), and 2% at 200 mesh (74 microns). The second is characterized in having 0.5% at 40 mesh (420 microns), 18% at 50 mesh (297 microns), 15% at 60 mesh (250 microns), 12% at 70 mesh (210 microns), 9% at 80 mesh (177 microns), 9% at 100 mesh (149 microns), 23% at 200 mesh (74 microns), 9% at 325 mesh (44 microns) and 5% at −325 mesh (where the negative size indicates that the particulate is smaller than this mesh). Other graphites are sold by Asbury Graphite in Asbury, N.J. under the designations Asbury 4172 and 4811. This first graphite is characterized as having 55% at 50 mesh (297 microns), 22% at 60 mesh (250 microns), 16% at 70 mesh (210 microns), and 6% at 80 mesh (177 microns). The second graphite is characterized as having 36% at 100 mesh (149 microns), 45% at 200 mesh (74 microns), 12% at 325 mesh (44 microns), and 8% at −325 mesh (the negative sign denotes particles smaller than the designated mesh). Other graphite fillers might be used instead of or in addition to the preferred graphites, and include: Ashbury A99, Ashbury 3243, Ashbury modified 4012, Ashbury 3285, Ashbury 230U; TimrexR KS 75 and 150, and TimrexR KC 44, all sold by TIMCAL of Westlake, Ohio; and Calgraph Sold by SGL Technic Inc of Valencia, Calif. This filler is used at a loading of at least 10% by weight. Other conductive fillers such as other forms of graphite (including graphite pitch-based fibers), conductive polymer metal particles, or metal coat particles may be used in conjunction with the graphite filler. Desirably conductive fillers are at least about 10, about 20, or about 25 weight percent of the molding composition and up to 50 weight percent. Alternatively this amount can be expressed as at least about 10 phr, more preferably at least about 25, or 50 phr or even over 100 phr. Alternatively stated the conductive fillers are present in an effective amount to result in a bulk conductivity of at least about 1 to 25 ohms when measured as described in the examples for a 6″ by 6″ molded plaque having a thickness of about 0.125 inches. If necessary for a particular application these values can be increased by the addition of conductive enhancers such as silver coated ceramic fibers, like Ag-Fiber sold by Energy Strategy Associates of Florida, or conductive polymers such as poly-paraphenyleneimine based products sold under the Tyrosid 1000 designation by J. H. Hinz Company of Westlake, Ohio.
An initiator is another component of the molding composition. The initiator initiates the copolymerization of the resin and the monomer(s). Initiators include any free radical initiator capable of forming radicals in the correct concentration under the molding conditions. They may include peroxides, hydroperoxides, redox systems, diazo compounds, persulfates, perbenzoates etc. The initiators are typically used in amounts of about 0.05 to about 5 weight percent, and more preferably about 0.1 to about 2 weight percent. Alternatively, these amount can be expressed in parts per hundred parts by weight of resin, i.e. from about 0.5 to about 4.0 phr, preferably from about 0.7 to about 3.0 phr, and most preferably from about 0.8 to about 2.25 phr. Alternatively high temperature initiators such as Di-cup, e.g. dicumyl peroxide can be used for molding applications where higher initiation temperatures are desirable. Peroxy initiators are preferred.
The inclusion of 0.5 to 10 phr, preferably about 1 to 8 phr, of a mold release agent, such as Tech-lube HV706, calcium stearate, zinc stearate, or the like may also be of advantage to achieving without machining the complex molded part of the present invention. Tech-lube HV706 is proprietary composition of fatty acids, glycerides, polymeric resin and phosphate surfactant sold by Tech-nick Products of New Jersey. A viscosity reducer can be used in combination with styrene to maintain the molding properties, and the decrease the cost of the composition.
Another optional component to the improved molding composition is a rheological modifier, which may act to increase the molecular weight such as by chain extension of the resin prepolymer. Suitable modifiers include Group II oxides and hydroxides, such as calcium or magnesium oxide. These modifiers may act to reduce shear and thus promote flow in the composition during molding. Fumed silica is an example of a substance, which may act mechanically to increase molding viscosity and therefore also be a suitable rheological modifier either alone or in combination with the previously mentioned ingredients.
Desirably the rheological modifiers are used in an effective amount to enhance molding properties, such as thickening the resin system prior to molding. Desirable amounts of group II oxides (including group II hydroxides and mixtures of these compounds) is from about 0.1 to about 1 or about 2 weight percent, more desirably from about 0.2 or about 0.3 to about 0.7 or about 0.8 weight percent. This can also be expressed as from about 0.5 to about 4.0 phr, preferably from about 1.0 to about 3.0 phr, and most preferably from about 1.5 to about 2.5 phr. Specific preferred compounds include magnesium oxide, or magnesium hydroxide or calcium oxide. An example of a suitable magnesium oxide additive is 99% pure magnesium oxide sold under the trade name “Elastomag” from Morton Thiokol, Inc. in Danvers, Mass. Other examples include a magnesium oxide dispersion sold under the trade name “PG-9033” by Plasticolors, and a magnesium hydroxide dispersion also sold by Plasticolors under the trade name “PG-91146”. Another suitable magnesium hydroxide is Barcroft, which is a powdered version. Fumed silica could be used at from about 0.5 to about 20 phr, preferably from about 1 to 10 phr.
Other components to the conductive molding composition include flame retardants such as decabromo flame retardants for example one sold under the tradename FR-1210 by Durr Marketing, used in the range of from about 5 to about 20 phr, and more preferably in the range of from about 7.5 to about 15 phr, and most preferably in the range of about 10 to about 15 phr. This can advantageously be combined with a synergist such as antimony trioxide such as SB203 sold by Durr Marketing and used in the range of from about 0.5 to about 10 phr, and preferably from about 1 to about 7.5 phr, and more preferably from about 3 to about 6 phr.
The composition also includes fibrous reinforcing agents such as cotton glass microfibers or graphite microfibers; flexibilizing agents; mold release agents; polymerization inhibitors to inhibit premature polymerization during storage or the initial stages of molding; viscosity modifiers like fumed silica; and mold lubricant like stearates of calcium, zinc or magnesium. The fibers may comprise chopped sized glass microfiber rovings at an amount below 20% for sound dampening, and preferably from about 10 to about 20%, and more preferably from about 15 to about 20% in particular for the combination blower housing/heater. The fibers are chopped to from about ⅛ to about ½ inch for BMC, to about ¼ to about 2 inches for SMC, and from about ¼ to about 1 inch for TMC. Carbon black may be added to influence the surface conductivity and to change the appearance of the molded product. Suitable carbon blacks include an electrically conductive low residue carbon black having a nitrogen surface area m2/g of 270, a STSA surface Area m2/g of 145 a sieve residue at 35 mesh of 0 ppm and at 325 mesh of 20 ppm as sold under the trade name Conductex 975 by Columbia Chemicals of Jamesburg, N.J. Also, suitable conductive carbon black is supplied by Akzo Nobel Chemicals of Chicago, Ill. under the trade name Ketjenblack EC-300 J and EC-600JD. Cabot Corporation of Boston, Mass. and Applied Science of Cedarville, Ohio supply conductive carbon blacks. It is noted that polyethylene and fumed silica can function as the rheological modifier in addition to the foregoing functions.
In addition, shrink control additives can advantageously be added to improve the surface characteristics and the dimensional stability of the resulting products. These shrink control additives include “anti-shrink” and “low profile additives” as part of this aspect of the invention. These additives generally include thermoplastics or elastomerics such as homopolymers of ethylene, styrene, vinyl toluene, alkyl methacrylates, polyethylene ether, polyphenylene oxide and alkyl acrylates. Additional examples include copolymers using the foregoing and in addition, vinyl chloride, vinyl acetate, acrylonitrile, and butadiene. In particular these co-polymers would advantageously include copolymers of vinyl chloride and vinyl acetate; styrene and acrylonitrile; methyl methacrylate and alkyl esters of acrylic acid; methyl methacrylate and styrene; methyl methacrylate and acrylamide; and SBS block copolymers. Particularly advantageous additives are thermoplastics, with saturated polyesters being preferred among these. These additives are generally used in the range of 10 to 50 weight percent based on the total weight of the additive and the resin system, i.e. the resin and any monomers. More preferably this range would be 20 to 45 weight percent, with a particularly preferred range of about 30 to 40 weight percent. These additives are usually added with the resin blending. As necessary the cure system may be adjusted to compensate for the presence of the additive.
The molding compositions may be formulated and mixed using a variety of mixing conditions including either continuous or batch and using a variety of known mixing equipment. Specific examples are set forth in the example section. The compositions may be advantageously stored for reasonable times before molding. The compositions can be molded by a variety of methods including compression, transfer, and injection molding or combinations of theses techniques. The compositions can be molded under typical conditions for these types of molding including at pressures from about 400 to about 9000 psi, and preferably from about 2000 to about 3500 psi, and most preferably from about 2500 to about 3000 psi and temperatures at from about 225 to about 400 degrees Fahrenheit. Dwell times are from about 10 seconds to about four minutes.
Otherwise conventional injection molding techniques apply as is discussed for example in U.S. Pat. No. 6,365,069 B2 incorporated by reference herein. It is preferable to avoid temperature variations at the mold level. At normal cure rates, the mold time for injection molding is typically around 5 to 600 seconds, or more usually 30 to 300 seconds or around one or two minutes. The process can be practiced for single or double gate cavity tools, or even for injection/compression processes in which the mold is slightly opened during fill and the mold is shut to compress the shot.
The articles from the composition desirably have tensile strength from about 2000 to about 6000 psi as measured in accordance with ASTM test No. D638 and flexural modulus from about 3000 to about 10,000 psi when tested in accordance with ASTM test no. D790.
Molded products made from the compositions of the present invention are useful for a variety of applications demanding complex configurations, conductivity, as well as strength, and corrosion resistance. One particularly advantageous product, which can be made by compression molding, is a combination heater blower housing shown in FIG. 1 . This housing combines the function of a heater with the blower housing of the prior art. The housing is typically molded in two parts and fitted together.
The following compositions are examples of ingredients that could be used in the composition of the present composition: Suitable resins may include, but not be limited to the following: Hetron 922 is available from Ashland Chemical Co in Columbus, Ohio. It is a low viscosity epoxy vinyl ester resin. It is about 55 wt. % solids and about 45 wt. % reactive monomer. Atlac 382ES is a resin from Reichhold Chemicals, Inc. in Research Triangle Park, N.C. It is characterized as a bisphenol fumarate resin. It is diluted to about 55 wt. % solids with styrene. Dion 6694 is a resin diluted to 55 wt. % solids in styrene. It is available from Reichhold Chemicals, Inc. It is characterized as a modified bisphenol fumarate polyester. Resin 42-2641 is available from Cook Composites and Polymers in Kansas City, Mo. It is diluted to 55 wt. % solids with styrene. It is characterized as an unsaturated polyester resin. ATLAC 3581-61 is sold by Reichhold Chemicals, Inc. It is characterized as a vinyl ester resin at 19 wt %, polyester at 27 wt % and urethane polymer at 4 wt % combined with 50 wt % styrene. Thus, it is diluted to 50 wt % solids with styrene. 580-05 is a resin from Reichhold Chemicals, Inc. It is characterized as a urethane-modified vinyl ester resin. It is diluted to 54 wt % solids with styrene. 9100 is a resin from Reichhold Chemicals, Inc. It is characterized as a bisphenol-epoxy vinyl ester. It is diluted to 54-58 wt % solids with styrene. Dow Derakane R8084 from Dow Chemicals, Inc. It is characterized as an elastomer-modified vinyl ester resin. It is diluted to 50-60 wt % solids with styrene. 9480-00 from is from Reichhold Chemicals, Inc. It is characterized as an epoxy novolac vinyl ester. It is diluted to 53.5 wt % solids with styrene. 31632 is from Reichhold Chemicals, Inc. It is characterized as a isocyanurate vinyl ester resin with 4 wt % polyether polyol. It is diluted to 60 wt % solids with styrene. Dow Derakane 797 from Dow Chemicals, Inc. It is characterized as a one pack resin which is an epoxy vinyl ester resin containing 7-13 weight percent of divinyl benzene, 5-15 weight percent of styrene butadiene rubber co-polymer, 2-6 weight percent of styrene homopolymer, and 0.5 to 1.5 weight percent of styrene-ethylene oxide block copolymer, as a low profile additive. It is diluted to 60-65 wt % solids with styrene. Dow Derakane 790 from Dow Chemicals, Inc. It is also characterized as a one pack resin which is an epoxy vinyl ester resin containing 5-15 weight percent of styrene butadiene rubber co-polymer, 2-6 weight percent of styrene homopolymer, and 0.5 to 1.5 weight percent of styrene-ethylene oxide block copolymer, as a low profile additive. It is diluted to 50-60 wt % solids with styrene. 31633-00 from Reichhold Chemicals, Inc. It is characterized as a isocyanurate vinyl ester resin with 4 wt % polyether polyol. It is diluted to 60 wt % solids with styrene. Derakane 780 is from Dow Chemicals, Inc. It is also characterized as a vinyl ester resin. It is diluted to 60-70 wt % solids with styrene. Polylite is from Reichhold Chemicals, Inc. Altac-G380 is from Reichhold Chemicals, Inc. Derakane 790 is from Dow Chemicals, Inc.
These resins can be combined with monomers, such as styrene, or Divinylbenzene HP from the Dow Chemical Company and characterized as 80 wt % divinyl benzene, 18 wt % ethylvinylbenzene, less than 0.12 wt % p-tert butylcatechol, less than 0.5 wt % diethylbenzene and less than 1 wt % of Naphthalene.
In addition, rheological modifiers can be used and include Elastomag from Morton Thiokol. Inc. in Danvers, Mass. It is characterized as 99% pure magnesium oxide The modifiers could also include FN-510, a linear low-density polyethylene from Equistar Chemicals, L.P. of Houston, Tex. and fumed silica, such as Cab-o-sil silica.
Suitable initiators include Vazo (2,2-azo bisisobutyronitrile) available from Dupont, I & B Industrial and Biochemical Dept, Wilmington Del., tert-butyl peroxy isopropyl carbonate (Triginox BPIC) available from Durr Marketing in Pittsburgh, Pa., t-butylperbenzoate (TBPB) available from Durr Marketing, and 1,3 di-t-butyl peroxy-3,5,5 trimethylcyclohexane catalyst (Trig 29B75) available from Durr Marketing.
Calcium stearate and zinc stearate sold as COAD 27 by the Norac Company, Incorporated of Azusa, Calif. can be used as mold release agents, as can Tech-Lube HV-706, which is a proprietary composition of fatty acids, glycerides, polymeric resin and phosphate surfactant.
Suitable graphite products include graphite 4012 available from Asbury Graphite in Asbury, N.J. It is characterized by having less than 10% greater than 150 microns and less than 10% smaller than 44 microns in diameter; SGL Ash02 characterized as a natural graphite flake product sold by SGL Corporation; XC-72.SGLV Fine characterized as a natural graphite flake product sold by SGL Corporation; conductive graphite flake available from Asbury Graphite in Asbury, N.J. under the trade designation 3243 and characterized by having less than 18% greater than 75 microns and less than 65% smaller than 44 microns in diameter; conductive flake graphite available from Asbury Graphite in Asbury, N.J. under the trade designation 230U and characterized by having 100% smaller than 44 microns in diameter; a synthetic graphite available from Asbury Graphite in Asbury, N.J. under the trade designation A99 and characterized by having less than 3% greater than 44 microns and less than 99% smaller than 44 microns in diameter; a synthetic graphite available under the designation KS 75, from Timrex America, Inc. and characterized by having less than 95% greater than 96 microns and less than 95% smaller than 75 microns in diameter; a synthetic graphite available under the designation KS 150, from Timrex America, Inc. and characterized by having at least 95% less than 180 microns in diameter; a synthetic graphite available under the designation KC44, from Timrex America, Inc. and characterized by having at least 90% less than 48 microns in diameter; a graphite available under the designation Timrex KS5-75TT from TimCal Ltd. of Bodio, Switzerland and characterized as having a particle distribution with d10 of 9.1 μm, a d50 of 38.8 μm, and a d90 of 70 μm, as determined by laser diffraction (Malvern); a synthetic graphite available under the designation of K103 from Applied Carbon Technology and having a particle size distribution characterized as 1.0% max at +80 mesh, 10.% max at 100 mesh and 10.0% max at −325 mesh; a graphite available under the designation Graphco from Asbury Graphite Mills having a particle size distribution characterized as 0.34% at +30 mesh, 58.9% at +50 mesh, 25.2% at +60 mesh, 10.9% at +80 mesh, and 5.7% at −80 mesh; a graphite available under the designation Graphite Sales FP143 or ElCarbo100 from Graphite Sales of Nova, Ohio and having a particle size distribution characterized as 5% at 2 mm, 30% at 0.8 mm, 50% at 0.2 mm, and 10% at pan; a graphite available under the designation Asbury T SO333 from Asbury Graphite Mills and characterized as having a particle distribution of 0.17% at screen 100; 54.90% at screen 200; 30.5% at screen 325, and a pan of 14.43%; a graphite available under the designation Asbury 4461 from Asbury Graphite Mills and characterized as having a particle distribution of 0.05% at +60 mesh; 35.52% of +100 mesh; 44.82% at +200 mesh; 11.77% at +325 mesh, and 7.9% at −325 mesh; a graphite available under the designation Asbury 3285 from Asbury Graphite Mills and characterized as having a particle distribution of 0.05% at +100 mesh; 10.46% at +200 mesh; 29.22% at +325 mesh, and 60.32% at −325 mesh; a graphite available under the designation Asbury 4592 from Asbury Graphite Mills and characterized as having a particle distribution of 0.02% at +60 mesh; 0.04% at +80 mesh; 0.78% at +100 mesh; 96.12% at +200 mesh; 1.3% at +325 mesh, and 1.74% at −325 mesh; a graphite available under the designation Asbury 4172 from Asbury Graphite Mills and characterized as having a particle distribution of 0.34% at +30 mesh; 54.87% at +50 mesh; 21.52% at +60 mesh; 16.19% at +70 mesh; 5.7% at +80 mesh; 1.38% at −80 mesh, and 1.45% at −200 mesh; a graphite available under the designation Asbury 4811 from Asbury Graphite Mills and characterized as having a particle distribution of 0.05% at +60 mesh; 35.52% at +100 mesh; 44.82% at +200 mesh; 11.77% at +325 mesh, and 7.9% at −325 mesh; a synthetic graphite available under the designation K100 from Applied Carbon Technology of Sommerville, N.J. and characterized as having a typical particle distribution of 0.18% at +30 mesh; 0.51-0.69% at +40 mesh; 22.16-24.98% at +50 mesh; 19.51% -22.17% at +60 mesh; 17.98%-19.77% at +70 mesh; 15.05% -15.84% at +80 mesh; 14.04%-17.84% at +100 mesh; 3.38%-5.62% at +200 mesh; 0.03% at +325 mesh, and 0.15% -0.50% at −325 mesh; a graphite available under the designation K112 from Applied Carbon Technology and characterized as having a typical particle distribution of 0.14% at +30 mesh; 0.48% at +40 mesh; 17.62% at +50 mesh; 14.53% at +60 mesh; 12.05% at +70 mesh; 9.47% at +80 mesh; 8.89% at +100 mesh; 23.12% at +200 mesh; 8.87% +325 mesh, and 4.83% at −325 mesh; and a graphite available under the designation Asbury 4580 from Asbury Graphite Mills and characterized as having a typical particle distribution of 0.05% at +10 mesh; 11.92% at +20 mesh; 62.33% at +30 mesh, and 25.64 at −30 mesh.
Carbon blacks can be used and include is a conductive carbon black nano fiber supplied under the trade name Pyrograph Applied Sciences, Inc. of Cedarville, Ohio; an electrically conductive low residue carbon black having a nitrogen surface area m2/g of 270, a STSA surface Area m2/g of 145 a sieve residue at 35 mesh of 0 ppm and at 325 mesh of 20 ppm as sold under the trade name Conductex 975 by Columbia Chemicals of Jamesburg, N.J.; conductive carbon black supplied by Cabot Corporation of Boston, Mass. under the trade name, Black Pearls; conductive carbon black supplied by Akzo Nobel Chemicals of Chicago, Ill. under the trade name Ketjenblack EC-300 J and EC-600JD. EC-300 J has an iodine absorption of 740-840 mg/g; a pore volume of 310-345 cm3/100 g and an apparent bulk density of 125-145 kg/m3. EC-600 JD has an iodine absorption of 1000-1150 mg/g; a pore volume of 480-510 cm3/100 g and an apparent bulk density of 100-120 kg/m3.
EXAMPLES
The following examples use the components set forth below.
Resin A is 31009 terephatic resin sold by Reichhold.
Resin B is Dow Derakane 780 from Dow Chemicals, Inc. It is also characterized as a epoxy novalac vinyl ester resin. It was diluted to 60-70 wt % solids with styrene.
Resin C is Q-8000 is a saturated polyester from Ashland Chemical.
Monomer A is styrene.
These ingredients are added together to comprise the base resin for 100 phr.
Flame retardant A is FR-121-(DBDPO)
Synergist A is Antimony Trioxide
Flow modifier A is FN-510, a linear low-density polyethylene from Equistar Chemicals, L.P. of Houston, Tex.
Initiator A is tert-Amyl peroxy-2-ethylhexanoate in a diluent of odorless mineral spirits, which is used as a catalyst (Trig 121C-75) available from Durr Marketing.
Initiator B is tert-butyl peroxy isopropyl carbonate (Triginox BPIC) available from Durr Marketing in Pittsburgh, Pa.
Inhibitor A is 91029 is BHT from Plasticolors.
Inhibitor B is 9139 is PBQ from Plasticolors.
Viscosity reducer A is BY-W-996 from BYK Chemie.
Mold release agent A is calcium stearate from Norac.
Graphite A is a synthetic graphite available under the designation K100 from Applied Carbon Technology of Sommerville, N.J. It is characterized as having a typical particle distribution of 0.18% at +30 mesh; 0.51-0.69% at +40 mesh; 22.16-24.98% at +50 mesh; 19.51%-22.17% at +60 mesh; 17.98% -19.77% at +70 mesh; 15.05% -15.84% at +80 mesh; 14.04% -17.84% at +100 mesh; 3.38% -5.62% at +200 mesh; 0.03% at +325 mesh, and 0.15% -0.50% at −325 mesh.
Graphite B is graphite 4012 available from Asbury Graphite in Asbury, N.J. It is characterized by having less than 10% greater than 150 microns and less than 10% smaller than 44 microns in diameter.
Thickener A is PG-9033P is a mag oxide dispersion from Plasticolors.
Glass fibers used are 973C-AB-113. The Glass fibers were from Owens-Corning Fiberglass and are characterized as continuous glass filaments hammer milled into a specific length used as a reinforcing and filler medium.
The molding compositions are generally prepared by adding the resin, monomer, initiator, inhibitor, mold release agent, and rheological modifier (if present) to a high shear cowls disperser and blending for 2 minutes at approximately 3,200 rpm. The conductive filler is added to the mix in a Baker Perkin, or Littleford continuous mixer and mixed 10 to 15 minutes. A Readco mixer can also be used and the ingredients can be ported in separately or added at the same time under cowls. When mixing is complete the composition is put in a suitable barrier bag and allowed to mature for approximately one day before molding.
The molding parameters for the molding compositions are as follows: General molding temperatures for 12″×12″ plaques at 0.125 inch was 280° F. up to 370° F. with a molding time of 3 minutes down to 108 seconds depending on the initiator and a charge weight of from 450 to 500 g. Preferably, the molding temperature for plaques was 310° F. with a molding time of about two minutes and a charge weight of 500 g.
The following procedure was used as an SMC pilot paste preparation for SL-790-Z6 compound as an example procedure:
The resin components were added to a 5 gallon pail with the initiator and the first of the inhibitor and blended under a Cowels disperser at approximately 3,200 rpm and then half of the graphite was slowly added, and then the flame retardants were added with continued blending. The thickener was slowly added and the remainder of the graphite and the mix was blended to a temperature of 110° F. Prior to running on a SMC machine, the thickener as added and the mix was blended for 2 minutes. The SMC machine 300 shown in FIG. 8 was started and run at a rate of 6 meters per minute. Equal parts of the paste 302 was transferred to SMC machine doctor boxes 304 . Glass rovings 306 were fed onto a carrier film 308 with the resin from chopper blades 310 . The glass chopper 310 was started when the poly with the paste deposited on it reached the chopper zone. After the glass was deposited it then meets the paste and poly from the upper doctor box where the two components go through a compaction zone 312 to get sandwiched between two carrier films 308 to wet out the glass fibers. The thickness was measured using a gamma gauge 314 . The resulting compound was wound onto a cardboard core and packaged in a box for later use. This was molded into test panels and also into prototype heater/blower housings.
Table I sets forth recipes of compositions and conductivity results in accordance
with the present invention which were tested for molding into heater/blower housings.
SL-790-
SL-790-
INGREDIENTS
SL-790-X2
X2 PHR
SL-790-X3
X3 PHR
SL-790-X4
SL-790-X4 PHR
SL-790-Y9
SL-790-Y9 PHR
31009
18.53
46.01
16.33
43.82
17.53
43.53
18.19
45.17
780
6.59
16.36
6.02
16.15
5.59
13.88
6.26
15.55
Q-8000
11.4
28.31
10.17
27.29
9.4
23.34
11.07
27.49
HP-DVB
STYRENE
3.75
9.31
4.75
12.74
7.75
19.25
4.75
11.80
PHR CHECK
100.00
100.00
100.00
100.00
FR-1210(DBDPO)
SB203 Antimony Trioxide
FN-510
1.04
2.58
1.04
2.79
1.04
2.58
1.04
2.58
TRIG 121C-75
0.18
0.45
0.18
0.48
0.18
0.45
0.18
0.45
TRIG BPIC
0.18
0.45
0.18
0.48
0.18
0.45
0.18
0.45
IN-91029
0.1
0.25
0.1
0.27
0.1
0.25
0.1
0.25
IN-9139
0.18
0.45
0.18
0.48
0.18
0.45
0.18
0.45
BYK-W-996
0.8
1.99
0.8
2.15
0.8
1.99
0.8
1.99
CAST
1.5
3.72
1.5
4.02
1.5
3.72
1.5
3.72
K-100 GRAPHITE
40
99.33
45
120.74
20
49.66
4012 GRAPHITE
40
99.33
20
49.66
PG-9033P
0.75
1.86
0.75
2.01
0.75
1.86
0.75
1.86
973C-AB-113
15
37.25
15
40.25
15
37.25
15
37.25
PHR COND. MEDIA
99.33
120.74
99.33
99.33
PHR NON-COND. MEDIA
148.99
152.94
148.99
148.99
ohms (plaques)
0.68
0.42
5.5
1.6
ohms (Actual Housing)
SL-790-
SL-790-
INGREDIENTS
SL-790-Z1
Z1 PHR
SL-790-Z2
Z2 PHR
SL-790-Z3
SL-790-Z3 PHR
SL-790-Z4
SL-790-Z4 PHR
31009
18.19
45.17
15.69
45.78
15.69
45.78
13.75
43.97
780
6.26
15.55
5.26
15.35
5.26
15.35
4.4
14.07
Q-8000
11.07
27.49
8.57
25.01
8.57
25.01
7.37
23.57
HP-DVB
STYRENE
4.75
11.80
4.75
13.86
4.75
13.86
5.75
18.39
PHR CHECK
100.00
100.00
100.00
100.00
FR-1210(DBDPO)
4
11.67
4
11.67
4
12.79
SB203 Antimony Trioxide
2
5.84
2
5.84
2
6.40
FN-510
1.04
2.58
1.04
3.03
1.04
3.03
1.04
3.33
TRIG 121C-75
0.18
0.45
0.18
0.53
0.18
0.53
0.18
0.58
TRIG BPIC
0.18
0.45
0.18
0.53
0.18
0.53
0.18
0.58
IN-91029
0.1
0.25
0.1
0.29
0.1
0.29
0.1
0.32
IN-9139
0.18
0.45
0.18
0.53
0.18
0.53
0.18
0.58
BYK-W-996
0.8
1.99
0.8
2.33
0.8
2.33
0.8
2.56
CAST
1.5
3.72
1.5
4.38
1.5
4.38
1.5
4.80
K-100 GRAPHITE
15
37.25
20
58.36
15
43.77
43
137.51
4012 GRAPHITE
25
62.08
20
58.36
25
72.95
PG-9033P
0.75
1.86
0.75
2.19
0.75
2.19
0.75
2.40
973C-AB-113
15
37.25
15
43.77
15
43.77
15
47.97
PHR COND. MEDIA
99.33
116.72
116.72
137.51
PHR NON-COND. MEDIA
148.99
175.08
175.08
182.28
ohms (plaques)
1.84
4.25
ohms (Actual Housing)
SL-791-
SL-791-
INGREDIENTS
SL-791-A6
A6 PHR
SL-791-A7
A7 PHR
SL-791-A8
SL-791-A8 PHR
SL-791-A9
SL-791-A9 PHR
31009
17.34
44.27
16.34
45.18
14.18
41.50
14.52
42.49
780
6.91
17.64
5.91
16.34
5.08
14.87
5.41
15.83
Q-8000
10.22
26.09
9.22
25.49
8.21
24.03
8.54
24.99
HP-DVB
STYRENE
4.7
12.00
4.7
12.99
6.7
19.61
5.7
16.68
PHR CHECK
100.00
100.00
100.00
100.00
FR 1210(DBDPO)
4
10.21
4
11.06
4
11.71
4
11.71
SB203 Antimony Trioxide
2
5.11
2
5.53
2
5.85
2
5.85
FN-510
1.04
2.66
1.04
2.88
1.04
3.04
1.04
3.04
TRIG 121C-75
0.18
0.46
0.18
0.50
0.18
0.53
0.18
0.53
TRIG BPIC
0.18
0.46
0.18
0.50
0.18
0.53
0.18
0.53
IN-91029
0.1
0.26
0.1
0.28
0.1
0.29
0.1
0.29
IN-9139
0.18
0.46
0.18
0.50
0.18
0.53
0.18
0.53
BYK-W-996
0.8
2.04
0.8
2.21
0.8
2.34
0.8
2.34
CAST
1.5
3.83
1.5
4.15
1.5
4.39
1.5
4.39
K-100 GRAPHITE
4012 GRAPHITE
35
89.35
35
96.77
37
108.28
35
102.43
PG-9033P
0.85
2.17
0.85
2.35
0.85
2.49
0.85
2.49
973C-AB-113
15
38.29
18
49.76
18
52.68
20
58.53
PHR COND. MEDIA
89.35
96.77
108.28
102.43
PHR NON-COND. MEDIA
165.94
179.71
184.37
190.23
ohms (plaques)
3.9
ohms (Actual Housing)
1.6
HI TEMP
SL-791-
SL-791-
SL-791-
HI TEMP
SL-791-
HI TEMP
INGREDIENTS
SL-791-B5
B5 PHR
SL-791-B6
B6 PHR
SL-791-B7
B7 PHR
SL-791-C6
C6 PHR
SL-791-G1
31009
17.34
44.27
15.52
41.75
16.34
45.18
17.61
44.06
17.95
780
6.91
17.64
6.41
17.25
5.91
16.34
7.18
17.96
7.51
Q-8000
10.22
26.09
9.54
25.67
9.22
25.49
10.48
26.22
10.81
HP-DVB
2.5
5.50
2.5
STYRENE
4.7
12.00
5.7
15.33
4.7
12.99
2.2
6.26
2.2
PHR CHECK
100.00
100.00
100.00
100.00
FR-1210(DBDPO)
5
12.76
5
13.45
5
13.82
5
12.51
5
SB203 Antimony Trioxide
3
7.66
3
8.07
3
8.29
3
7.51
3
FN-510
1.04
2.66
1.04
2.80
1.04
2.88
1.04
2.60
1.04
TRIG 121C-75
0.18
0.46
0.18
0.48
0.18
0.50
0.18
0.45
0.18
TRIG BPIC
0.18
0.46
0.18
0.48
0.18
0.50
0.18
0.45
0.18
IN-91029
0.1
0.26
0.1
0.27
0.1
0.28
0.1
0.25
0.1
IN-9139
0.18
0.46
0.18
0.48
0.18
0.50
0.18
0.45
0.18
BYK-W-996
0.8
2.04
0.8
2.15
0.8
2.21
CAST
1.5
3.83
1.5
4.04
1.5
4.15
1.5
3.75
1.5
K-100 GRAPHITE
4012 GRAPHITE
30
76.59
30
80.71
36
99.53
30
75.06
25
PG-9033P
0.85
2.17
0.85
2.29
0.85
2.35
0.85
2.13
0.85
973C-AB-113
18
45.95
20
53.81
15
41.47
18
45.03
22
PHR COND. MEDIA
76.59
80.71
99.53
75.06
PHR NON COND. MEDIA
178.71
188.32
176.94
175.13
ohms (plaques)
22.7
9.65
8.8
21
ohms (Actual Housing)
3.9
4.5
SL-790-
SL-790-
INGREDIENTS
SL-790-Z5
Z5 PHR
SL-790-Z6
Z6 PHR
SL-791 A4
SL-791-A4 PHR
SL-791 A5
SL-791-A5 PHR
31009
15.69
45.78
15.69
45.78
15.02
43.89
15.02
43.89
780
5.26
15.35
5.26
15.35
4.6
13.44
4.6
13.44
Q-8000
8.57
25.01
8.57
25.01
7.9
23.09
7.9
23.09
HP-DVB
STYRENE
4.75
13.86
4.75
13.86
6.7
19.58
6.7
19.58
PHR CHECK
100.00
100.00
100.00
100.00
FR-1210(DBDPO)
4
11.67
4
11.67
4
11.69
4
11.69
SB203 Antimony Trioxide
2
5.84
2
5.84
2
5.84
2
5.84
FN-510
1.04
3.03
1.04
3.03
1.04
3.04
1.04
3.04
TRIG 121C-75
0.18
0.53
0.18
0.53
0.18
0.53
0.18
0.53
TRIG BPIC
0.18
0.53
0.18
0.53
0.18
0.53
0.18
0.53
IN-91029
0.1
0.29
0.1
0.29
0.1
0.29
0.1
0.29
IN-9139
0.18
0.53
0.18
0.53
0.18
0.53
0.18
0.53
BYK-W-996
0.8
2.33
0.8
2.33
0.8
2.34
0.8
2.34
CAST
1.5
4.38
1.5
4.38
1.5
4.38
1.5
4.38
K-100 GRAPHITE
40
116.72
35
102.13
5
14.61
4012 GRAPHITE
5
14.59
35
102.28
40
116.89
PG-9033P
0.75
2.19
0.75
2.19
0.8
2.34
0.8
2.34
973C-AB-113
15
43.77
15
43.77
15
43.83
15
43.83
PHR COND. MEDIA
116.72
116.72
116.89
116.89
PHR NON-COND. MEDIA
175.08
175.08
175.34
175.34
ohms (plaques)
2.04
6.9
ohms (Actual Housing)
1
3.2
HI TEMP
HI TEMP
HI TEMP
INGREDIENTS
SL-791-G1 PHR
SL-791-G2
SL-791-G2 PHR
31009
48.81
18.62
43.33
780
18.33
8.18
19.04
Q-8000
26.39
11.47
26.69
HP-DVB
6.10
2.5
5.82
STYRENE
5.37
2.2
5.12
PHR CHECK
100.00
100.00
FR-1210(DBDPO)
12.20
5
11.64
SB203 Antimony Trioxide
7.32
3
6.98
FN-510
2.53
1.04
2.42
TRIG 121C-75
0.44
0.18
0.42
TRIG BPIC
0.44
0.18
0.42
IN-91029
0.24
0.1
0.23
IN-9139
0.44
0.18
0.42
BYK-W-996
CAST
3.66
1.5
3.49
K-100 GRAPHITE
4012 GRAPHITE
61.02
20
46.54
PG-9033P
2.07
0.85
1.98
973C-AB-113
53.70
25
58.18
PHR COND. MEDIA
61.02
46.54
PHR NON-COND. MEDIA
183.04
186.18
ohms (plaques)
ohms (Actual Housing)
FIG. 3 is a graph of the sound speed versus temperature for a resin composition testing various loadings of glass fibers and correspondingly decreased loadings of another filler, BaSO 4 . A similar graph is shown for various compositions comparing conductive and non-conductive compounds in FIG. 4 . The plots indicate the somewhat complex relationship between loading and sound transmission. FIGS. 5 and 6 are graphs showing the conductive of various formulations for test plaques and actual housings.
Table II shows mechanical property testing on Conductive SMCs. The specimens used for testing were cut from 12×12×0.125 inch panels that were molded in the standard method.
TABLE II
Mechanical
Property
X
SD
X
SD
SL791-A4
SL791-A5
Tensile Strength (psi)
4807.14
706.65
5097.50
1132.40
Tensile Mod. (psi × 10 6 )
0.87
0.16
1.02
0.08
% Elongation (percent)
0.80
0.33
0.89
0.31
Tensile Energy (psi)
25.01
14.39
33.33
17.70
Flex Strength (psi)
13456.63
3096.88
13700.25
2947.58
Flex Mod. (psi × 10 6 )
0.37
0.10
0.94
0.07
Notched Izod (ft-lbs/in)
7.57
2.01
8.69
1.96
Unnotched Izod (ft-lbs/in)
11.98
4.26
14.75
4.54
SL791-A6
SL791-A7
Tensile Strength (psi)
4966.25
801.16
5983.75
2198.74
Tensile Mod. (psi × 10 6 )
0.95
0.08
1.16
0.20
% Elongation (percent)
0.71
0.14
0.74
0.37
Tensile Energy (psi)
21.30
6.31
32.78
27.55
Flex Strength (psi)
12184.57
1630.66
17144.38
5025.52
Flex Mod. (psi × 10 6 )
0.87
0.05
0.94
0.12
Notched Izod (ft-lbs/in)
9.15
3.02
12.31
2.87
Unnotched Izod (ft-lbs/in)
12.33
2.12
14.18
4.79
Table III shows results from flammability testing using samples molded in the standard method and tested according to UL's Test for Flammability of Plastice Materials for Parts in Devices and Applicances. The specimens were conditioned to the first conditioning period (48 hrs@23° C.) only to help meet the date needed.
Past data has shown no difference in results between the two conditioning periods. If the table recites “NR” testing was Not Required because: 1) testing of the same compound passed at a tower thickness, 2) testing of the same compound failed at a higher thickness. In the parenthesis following a “NR” is the assumed testing result. A hypen shows results from a needed recheck because of a failure. The minimum passing result for each compound is listed in bold.
TABLE III
Compound
Series
Batch
Test Type
Thickness
Result
SL791-A4
EXP-15
1 (pilot)
V-0
0.060
Fail - Fail
0.080
Pass
0.100
NR (Pass)
5 V
0.060
Pass
0.080
NR (Pass)
0.100
NR (Pass)
SL791-A5
EXP-15
1 (pilot)
V-0
0.060
Fail - Fail
0.080
Pass
0.100
NR (Pass)
5 V
0.060
Pass
0.080
NR (Pass)
0.100
NR (Pass)
SL791-A6
EXP-15
1 (pilot)
V-0
0.060
Fail - Fail
0.080
Fail - Fail
0.100
Pass
5 V
0.060
Fail - Pass
0.080
NR (Pass)
0.100
NR (Pass)
SL791-A7
EXP-18
1 (pilot)
V-0
0.060
Fail - Fail
0.080
Fail - Fail
0.100
Pass
5 V
0.060
Pass
0.080
NR (Pass)
0.100
NR (Pass)
Table IV sets forth Mechanical Property testing as set forth in Table II but for SMC with varying amounts of K100 graphite.
TABLE IV
Mechanical
SL790-Z4
SL790-Z5
SL790-Z6
Property
X
SD
X
SD
X
SD
Tensile Strength (psi)
3612.50
1255.61
5662.50
796.86
3705.00
933.61
Tensile Mod. (psi × 10 6 )
1.03
0.09
1.18
0.19
1.03
0.21
% Elongation (percent)
0.53
0.38
0.69
0.11
0.42
0.15
Tensile Energy (psi)
9.85
7.25
28.55
10.34
10.21
6.79
Flex Strength (psi)
9557.63
3339.44
11461.88
2629.28
9752.25
3754.08
Flex Mod. (psi × 10 6 )
0.76
0.09
0.79
0.12
0.71
0.10
Notched Izod (ft-lbs/in)
5.67
1.21
6.03
1.63
6.06
1.48
Unnotched Izod (ft-lbs/in)
9.08
4.16
9.33
3.83
9.53
2.50
Table V sets forth the results of flammability testing for the compounds of Table IV and according to the description for Table III.
TABLE V
Compound
Series
Batch
Test Type
Thickness
Result
SL790-Z4
EXP-15
1
V-0
0.060
ALL PASS
0.080
0.100
5 V
0.060
ALL PASS
0.080
0.100
SL790-Z5
EXP-15
1
V-0
0.060
ALL PASS
0.080
0.100
5 V
0.060
ALL PASS
0.080
0.100
SL790-Z6
EXP-15
1
V-0
0.060
ALL PASS
0.080
0.100
5 V
0.060
ALL PASS
0.080
0.100
Additional flammability testing results are set forth in Tables VI, VII, and VIII.
TABLE VI
Compound
Series
Lot No.
Test Type
Thickness
Result
SL790-Y9
Exp-15
7-14-03-1
V-0
0.060
NR (Fail)
(LAB)
0.080
NR (Fail)
0.100
Fail - Fail
5 V
0.060
NR (Fail)
0.080
NR (Fail)
0.100
Fail - Fail
SL790-Z1
V-0
0.060
NR (Fail)
0.080
NR (Fail)
0.100
Fail - Fail
5 V
0.060
NR (Fail)
0.080
NR (Fail)
0.100
Fail - Fail
SL790-Z2
V-0
0.060
PASS
0.080
NR (Pass)
0.100
NR (Pass)
5 V
0.060
PASS
0.080
NR (Pass)
0.100
NR (Pass)
SL790-Z3
V-0
0.060
PASS
0.080
NR (Pass)
0.100
NR (Pass)
5 V
0.060
PASS
0.080
NR (Pass)
0.100
NR (Pass)
TABLE VII
SAMPLE DESCRIPTION
SL-791-A8 SMC
Exp-18
37%4012Graphite/DBDPO/SB
SL-791-A9 SMC
Exp-20
35%4012Graphite/DBDPO/SB
RESULTS
Compound
Thickness
Test Type
Result
SL-791-A8
0.060
V-0
Pass
5 V
Pass
SL-791-A9
0.060
V-0
Fail/recheck Fail
5 V
Pass
0.080
V-0
Pass
TABLE VIII
SAMPLE DESCRIPTION
SL-791-B5 SMC
Exp-18
30%4012Graphite/DBDPO/SB
SL-791-B6 SMC
Exp-20
30%4012Graphite/DBDPO/SB
SL-791-B7 SMC
Exp-15
36%4012/DBDPO/SB
RESULTS
Compound
Thickness
Test Type
Result
SL-791-B5
0.060
V-0
Pass
5 V
Pass
SL-791-B6
0.060
V-0
Pass
5 V
Pass
SL-791-B7
0.060
V-0
Fail/recheck Fail
5 V
Pass
0.080
V-0
Pass
Testing was performed according to ASTM standards for rigid plastics. Additional tests were run to study the effect of graphite loading and particle size with a preliminary ohm target of 2 ohms, in particular for use as a combination heater/blower housing. The test method to determine through surface conductivity was the same as used to determine the values presented for the plaques in Table I and uses a ohm meter forming a circuit with to ¼″ to ½″ braided copper strap bonded to opposing parallel ground sides at the top, and in line with the edge of a 6″ by 6″ by 0.125″ plaque with the copper strap being bonded to each ground side by silver filled epoxy adhesive. This method is meant to be the method for determining the through surface conductivity for the claims. The results are set forth below in
TABLE IX
Graphite
K-1100%/
4012/
Glass
Formulation
%
250 mic
75μ
94 5 V .060″
Ohms
%
SL790-Y9
40
20
20
fail
1.3
15
SL790-X4
43
43
0
pass
31
15
SL-790-Z2
40
20
20
pass
2.2
15
SL-790-Z3
40
15
25
pass
2.2
15
SL-790-Z6
40
35
5
pass
1.5
15
While in accordance with the Patent Statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims. | The invention provides molding compounds that are particularly suitable to be molded into an article such as a heating element that will conduct heat and not burn when an electric current is passed through the article. These compounds are generally liquid thermosetting molding resins which comprise a thermoset resin matrix such as a terephthalate polyester which can include blends of polyester and/or vinyl ester with a significant loading of conductive inorganic filler, typically graphite. The compositions also include flame and sound retardant additives, and glass fibers. They are further formulated to meet the desired molding characteristics; to withstand the operating temperatures to which they will be exposed; and to have a predetermined strength and a desirable user interface including appearance, and odor. Typically, the compounds will have a glass transition temperature from about 160° C. (320° F.) to about 195° C. (383° F.). | 2 |
FIELD OF THE INVENTION
The present invention relates to apparatus for coating a web of paper in general and to short dwell coater apparatus in particular.
BACKGROUND OF THE INVENTION
Paper of specialized performance characteristics may be created by applying a thin layer of coating material to one or both sides of the paper. The coating is typically a mixture of a fine plate-like mineral, typically clay or particulate calcium carbonate; coloring agents, typically titanium dioxide for a white sheet; and a binder which may be of the organic type or of a synthetic composition. Coated paper is typically used in magazines, commercial catalogs and advertising inserts in newspapers. The coated paper may be formed with a smooth bright surface which improves the readability of the text and the quality of photographic reproductions. Coated papers are divided into a number of grades. The higher value grades, the so-called coated free-sheet, are formed of paper fibers wherein the lignin have been removed by digestion. Less expensive grades of coated paper contain ten percent or more ground-wood pulp which is less expensive than pulp formed by digestion.
Coated ground-wood papers include the popular designation "lightweight coated" (LWC) paper. For lightweight coated paper, coating weight is approximately thirty percent of total sheet weight and these grades of paper are popular with magazine publishers, direct marketers, and commercial printers as the lighter weight paper saves money on postage and other weight-related costs. With the increasing demand for lighter weight, lower cost coated papers, there is an increasing need for more efficiency in the production of these paper grades.
Paper is typically more productively produced by increasing the speed of formation of the paper and coating costs are kept down by coating the paper while still on the papermaking machine. Because the paper is made at higher and higher speeds and because of the advantages of on-machine coating, the coaters in turn must run at higher speeds. The need in producing lightweight coatings to hold down the weight of the paper and the costs of the coating material encourages the use of short dwell coaters which subject the paper web to the coating material for a short period of time and thus limit the depth of penetration of the coating and hence the coating weight.
High speed coater machines are key to producing lightweight coated papers cost-effectively. However, the use of short dwell coaters at high machine speeds has led to defects in the coating, typically coating streaks. Coating streaks are caused by air entrained in the boundary layer of the raw stock or paper web. The boundary layer air forms bubbles in the coating pond, and the bubbles pressing up against a metering blade prevent the coating from uniformly flowing under the blade.
What is needed is a means for preventing the formation of large bubbles in the coating pond adjacent to the metering blade.
SUMMARY OF THE INVENTION
The short dwell coater of this invention employs a plurality of spaced apart rods or bars which extend across the coater in the cross-machine direction. The bars are submersed in the coating pond within the coater head. The paper web is engaged against a backing roll, and travels through the coating pond at the end of which is positioned a metering blade which applies the coating to the web. The bars are spaced one thousandth to 250 thousandths of an inch from the paper being coated. The bars induce a turbulent flow which shears bubbles of air entrained in the coating pond, thereby reducing the bubble diameters to perhaps about eight-thousandths of an inch with no larger bubbles left over. The turbulence-generating bars may be rectangular in cross-section and may be mounted on upstanding flanges which extend from the coater head base to support the bars closely spaced from the backing roll. The metering blade is positioned downstream of the bars. Coating is fed into the pond near the metering blade. The coating flows under the bars. From the bars part of the flow goes over the lip forming the upstream edge of the coating pond, while the remainder of the coating is drawn back toward the metering blade over the metering blade. Entrained bubbles are reduced in size as the coating flows past the bars and onto the metering blade for application to the web.
It is a feature of the present invention to provide a short dwell coater which may be run at higher speeds.
It is another feature of the present invention to provide a short dwell coater for use in on-machine coating.
It is also a feature of the present invention to provide a short dwell coater which prevents the formation of streaks at high coating velocities.
It is a further feature of the present invention to provide a short dwell coater which uniformly wets a coating base.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevational, isometric view, partly cut away, of the short dwell coater of this invention.
FIG. 2 is a side-elevational, cross-sectional view of a prior art short dwell coater.
FIG. 3 is a bottom plan view of a paper web passing through the prior art coater of FIG. 2 taken along section line 3--3.
FIG. 4 is a cross-sectional, elevational view of the short dwell coater of FIG. 1.
FIG. 5 is a cross-sectional view of the short dwell coater of FIG. 4 taken along section line 5--5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to FIGS. 1-5 wherein like numbers refer to similar parts, an improved short dwell coater 20 is shown in FIGS. 1, 4, and 5. The coater 20 has a coater head 22 which is disposed below a backing roll 24 such that a paper web 36 to be coated is engaged by the backing roll as it passes through the coater head 22. The coater head 22 has a housing 23 which defines a pond 28 which extends at least the width of the web 36 and which receives coating to be applied to the web.
A plurality of parallel turbulence generating bars 21 are mounted to the coating head 22 housing 23 and extend in a cross-machine direction within the pond 28. The pond 28 is formed between a premetering blade 30 and a baffle plate 32. Coating 34 is supplied from a pressurized coating source to the pond from an inlet 26 formed in the housing beneath the pond, and counterflows from the premetering blade 30 to the baffle plate 32 in the up-machine direction.
The paper web 36 moves through the pond in a direction opposite to the flow of the coating 34. The coating 34 overflows the baffle plate 32 over a lip 40 and is collected in a trough 42 for reuse. As the web 36 moves through the pond, the coating 34 contacts the paper along a constantly moving and fluctuating dynamic contact line 46. The bars 21 are mounted on narrow flanges 33 which support the bars in closely spaced relation to the moving web 36.
In prior art coaters, such as the coater 47 shown in FIG. 2, the dynamic contact line 49 is in constant motion with respect to the premetering blade 51 and beyond a certain web speed fingers of air 50, as shown in FIG. 3, will on occasion pass under the premetering blade 51 to cause streaks 52 on the coated paper 48. Air is induced into the pond by a boundary layer of air which is dragged through the gap between the lip and the backing roll along with the fast moving paper web. As shown in FIG. 2, the wetted surface of the web 53 drags a boundary layer of coating 34 along with the web setting up a high velocity flow indicated by arrows 54 toward the premetering blade 51.
The bars 21 positioned in the pond of the coater head 22 of the coater 20 of this invention, as shown in FIG. 4, project into the fluid flow along the web and create fluid dynamic shear between the bars 21 and the web 36. Shear in the coating 34 between the bars 21 and the web 36 means that the velocity of the coating changes rapidly between the velocity of the coating which is attached to the web, which may be moving at a hundred feet per second, and the velocity of the coating which is in the boundary layer in the bars 21 which is stationary.
Because the bars 21 are spaced between a few thousandth and a quarter of an inch away from the web, it may be seen that the hydrodynamic shear rate may vary between a few feet/min per thousandth of an inch to a few hundreds of feet/min per thousandth of an inch. These extremely high hydrodynamic shears when interacting with air bubbles which are moving along in proximity to the web cause the bubbles to be torn apart. The size of a bubble being formed is of course dependent on the hydrodynamic shear. In general, the bubbles will be reduced in size until the surface tension which holds the bubble together is able to overcome the shearing action of the fluid. In an experiment where water was run through a shear generator, one inch diameter bubbles were reduced in size to an average size below 0.2 millimeters in diameter. Greater machine speed, which tends to entrain more air, induces greater shear at the bars which causes bubble size to be more greatly reduced.
The structure of a bubble is defined by the surface tension which holds the bubble together. Surface tension is a two-dimensional force, thus as the bubble size decreases, the surface tension forces fall off as the second power of bubble size. However this force becomes much stronger relative to the volume of the bubble which falls off as the third power. Thus, extremely small bubbles can withstand a greater hydrodynamic shear.
Extremely small bubbles do not present the same problem as large bubbles, and are less likely to form streaks on the finished coated paper. The small bubbles may be smaller than the thickness of the coating in which case they may have little impact on the surface properties of the coated paper. Further, to the extent the bubbles create voids, they merely create some additional porosity in the coating over that induced by the drying process.
Extremely small bubbles have high surface energy relative to the volume and can create extremely high pressures within the bubbles which can force the gases into solution with the coating.
Another factor in the formation of small bubbles is that certain chemicals, such as detergents, when mixed in water generally lead to smaller bubbles than those found in pure water. This is probably because the chemicals reduce the surface tension energy and so the bubbles must be smaller to withstand the hydrodynamic shears produced. Such chemicals are in most cases already present in the coating formulation to aid in the dispersion of the solids suspended in the liquid. However, if desirable, additional chemicals for reducing the surface tension could be added to the coating. The problem of streaking becomes more severe as the velocity of the papermaking machine and the web 36 increase. On the other hand, the hydrodynamic shear caused by the turbulence generating bars 21 is directly proportional to the speed. Thus, as the problem of streaking increases with increasing machine speed, the solution presented by the bars 21 also increases.
As shown in FIG. 4, a final metering blade 62 is positioned downstream and down-machine from the coating head 22. The final metering blade scrapes as much as ninety percent or more of the coating which has been applied to the paper, and forms the final even layer which is dried on the web 36. The coating removed by the final metering blade 62 is collected in a trough 66 for reuse. The coated web 36 then leaves the backing roll 24 and passes over a turning roll 78 and enters a dryer section (not shown).
It should be understood, however, that the premetering blade 30 could be replaced by a final metering blade. It should also be understood that wherein the turbulence generating bars are shown supported by flanges 33 which are spaced apart to allow the flow of coating under the bars, other means for supporting the bars could be used including wire rods, or extending the bars 21 down to the coater head 22, and drilling holes through the bars for the passage of the coating.
It should also be understood that the number of bars used may be varied and that one, two, three, or more bars may be effective. It should also be understood that although the gap between the bars and the paper web may vary between one-thousandth of an inch and about a quarter of an inch, the gap will depend on the speed of the web being coated, the viscosity and composition of the coating, and the thickness of the coating which it is desired to apply to the web.
It should also be understood that although the coating is shown entering adjacent to the premetering blade and counterflowing beneath the turbulence-generating bars, the flow could be brought in near the baffle plate lip or between the baffle plate lip and the premetering blade. Thus, in general it should be understood that the turbulence generating bars can be used in any short dwell coater having a pond through which a paper web is drawn.
Referring to FIG. 4, it should be noted that in an alternative embodiment coater, a plurality of bars which are spaced from each other in the machine direction may be formed with a solid underlying support to prevent flow through the bars. Such an arrangement would still be expected to produce advantageous results in reducing bubble size.
It should be understood that the last bar in the machine direction could be tapered towards the backing roll to reduce the likelihood of a buildup of a bubble downstream of the shear generating bars. In addition other means known to those skilled in the art could be used to prevent the formation of a vortex after the bars.
It should be understood that although a paper web is described, the coating could be done on a roll surface which is later transferred to a paper web, such as in a size press.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims. | A coater head has a housing which defines a coating pond supplied with coating under pressure. A plurality of bars extend within the coating pond in the cross-machine direction, and are spaced parallel to one another in the machine direction. A paper web is engaged against a backing roll, and travels through the coating pond past a metering blade which applies coating from the pond to the web. The bars induce a turbulent flow which shears bubbles of air entrained in the coating pond, thereby reducing the bubble diameters and air-induced imperfections in the coating. Greater machine speed, which tends to entrain more air, induces greater shear at the bars which causes bubble size to be more greatly reduced. | 3 |
FIELD
[0001] This invention relates generally to tagging, more particularly, to systems and methods for community tagging.
DESCRIPTION OF THE RELATED ART
[0002] A tag can be defined as a keyword or term associated with or assigned to an item of information, e.g., a picture, an article, video file, Wiki page, etc. The tag aids in defining the item of information and enables keyword-based classification of information it is applied thereto.
[0003] Tags are usually chosen informally and personally by either the author and/or user of the item of information. Tags are typically used in dynamic, flexible, automatically generated Internet taxonomies for online resources such as computer files, web pages, digital images, and Internet bookmarks, and current generation of web browsers.
[0004] While tags can be beneficial in organizing information, tagging is not without its drawbacks and disadvantages. For example, the tag does not typically convey any meaning or semantics of the tag. The tag “apple” can refer to the fruit, the computer company, a British music label and/or a female singer. This lack of semantic distinction in tags can lead to inappropriate connection between items. Moreover, the selection of tag terms can be highly user-specific. Different users can use drastically different terms to describe the same concept. As an example, the terms that can be used to tag a version of Apple Computer's operating system can be “Mac OS X”, “Tiger”, “closed” and many other terms. Accordingly, users of tagging systems are forced to make judgments based on the number of connections and the choices of tag terms, whether possible connections between items are valid for their interest.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Various features of the embodiments can be more fully appreciated, as the same become better understood with reference to the following detailed description of the embodiments when considered in connection with the accompanying figures, in which:
[0006] FIG. 1 depicts an exemplary system in accordance with an embodiment;
[0007] FIG. 2 illustrates an exemplary service portal of the system shown in FIG. 1 in accordance with another embodiment;
[0008] FIG. 3 depicts an exemplary knowledge server of the system shown in FIG. 1 in accordance with yet another embodiment;
[0009] FIG. 4 illustrates an exemplary issue tracker server of the system shown in FIG. 1 in accordance with yet another embodiment;
[0010] FIG. 5 depicts an exemplary chat server of the system shown in FIG. 1 in accordance with yet another embodiment;
[0011] FIG. 6 illustrates an exemplary diagram of the tagging module in accordance with yet another embodiment;
[0012] FIG. 7 depicts an exemplary flow diagram implemented by the tagging module in accordance with yet another embodiment; and
[0013] FIG. 8 illustrates another exemplary flow diagram implemented by the tagging module in accordance with yet another embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0014] For simplicity and illustrative purposes, the principles of the present invention are described by referring mainly to exemplary embodiments thereof. However, one of ordinary skill in the art would readily recognize that the same principles are equally applicable to, and can be implemented in, all types of information portals, and that any such variations do not depart from the true spirit and scope of the present invention. Moreover, in the following detailed description, references are made to the accompanying figures, which illustrate specific embodiments. Electrical, mechanical, logical and structural changes may be made to the embodiments without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense and the scope of the present invention is defined by the appended claims and their equivalents.
[0015] Embodiments pertain generally to a method of organizing and accessing a knowledgebase. More particularly, a knowledgebase can be tagged with an approved set of tags as well as a community set of tags. The approved set of tags can be developed from the community set of tags. Users with super privileges can apply a predefined set of tags to knowledgebase items, where the knowledgebase items can be articles, posts, or other similar information useful to the user community. Ordinary users can apply tags to knowledgebase items based on a community set of tags, where the community set of tags can be any term supplied by an ordinary user. The community set of tags can also be configured to show the popularity of any tag within the set. Accordingly, a subsequent user can search the knowledgebase based on the approved set of tags, the community set of tags, or a combination of the two tags. The subsequent user can focus the search by determining the popularity of tag terms within the community set of tags.
[0016] FIG. 1 illustrates an exemplary system 100 in accordance with an embodiment. It should be readily apparent to those of ordinary skill in the art that the system 100 depicted in FIG. 1 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified. Moreover, the system 100 may be implemented using software components, hardware components, or combinations thereof.
[0017] As shown in FIG. 1 , the system 100 includes a service portal 105 coupled to a network 125 . Users 130 can interface with the service portal 105 through the network 125 . The network 125 can be a combination of local area networks, wide area networks, public networks, and private networks such as the Internet.
[0018] The users 130 can interface with the service portal 105 using computing platforms such as personal computers, workstations, private local area networks (e.g., business entity or government entity) or other similar device that can provide network access and interact with the service portal 105 .
[0019] In some embodiments, the service portal 105 can be configured to provide services. As a non-limiting example, the service portal 105 can be configured to provide information for users to research, compare and purchase software, hardware and consulting services in support of the those software and/or hardware purchases. The service portal 105 can also be configured to provide support services by subscription to those same software and/or hardware purchases. The service portal 105 can further be configured to provide a knowledgebase for a user in a community can search for answers regarding issues. The community can comprise of registered and non-registered users.
[0020] The service portal 105 can be configured to provide at least the described services with a service backend 135 . The service backend 135 can comprise at least a knowledge server 110 , an issue tracker server 115 and a chat server 120 .
[0021] The knowledge server 110 can be configured to provide a knowledgebase for the system 100 . The knowledgebase can comprise of Wiki documents, articles, frequently asked questions (FAQs), transcripts of chat sessions and other informational items related to issues deemed worth discussing by the community. The knowledge server 110 can also be configured to search and retrieve requested informational items from its own database but also from third party sites such as Google™, Yahoo™, etc. The knowledge server 110 can then rank and prioritize the search results from internal and external sources for the requesting user, based on a single interface provided by the server portal 105 . In some embodiments, the knowledge server 110 can be implemented on a separate server using open-source technologies.
[0022] The service portal 105 can also be configured to interface with the issue tracker server 115 , which provide support services for the service portal 105 . More particularly, a user may have a problem or issue with a purchased software and/or hardware from the service portal 105 . The user can return to the service portal 105 and request support services based on a purchased service subscription through a user interface generated by the service portal 105 . The service portal 105 can redirect the support request to the issue tracker server 115 . The issue tracker server 115 can open an associated service ticket for resolution by support personnel. The issue tracker server 115 can also be configured to attach transcripts of any chat sessions between the support personnel and the user as well as documenting the solution(s) to the issue of the user. In some aspects, the documented solution can be converted into an article, added to a frequently asked question list, Wiki page, etc., and passed onto the knowledge server 110 .
[0023] The chat server 120 can be configured to couple with the service portal 105 . A user with an issue or question can log into the service portal 105 and search for solutions and/or answers. The service portal 105 can generate a user interface and display an option for requesting assistance via a chat session. If a user selects this option, the service portal 105 can pass the request over to the chat server 120 . The chat server 120 can be configured to provide the chat session to the user via another user interface provided by the service portal 105 . The chat server 120 can also be configured to save the chat sessions for later review. For example, support personnel can turn the chat session into an article or extract discussed solutions in the chat sessions into or add to a frequently asked questions list.
[0024] FIG. 2 illustrates a more detailed block diagram of the service portal 105 in accordance with another embodiment. It should be readily apparent to those of ordinary skill in the art that the service portal 105 depicted in FIG. 2 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified.
[0025] As shown in FIG. 2 , the service portal 105 can comprise a user interface module 205 , a controller module 210 , a broker module 215 , a model module 220 , a database interface module 225 , and a logging module 245 . The user interface module 205 can be configured to generate the graphical user interfaces (GUIs) for users to interact with service portal 105 . The user interface module 205 can generate the necessary functionality of the GUIs based on hypertext markup language (“HTML”) code, cascading style sheets (“CSS”) and/or Java Server Pages (JSP).
[0026] The user interface module 205 can be configured with a controller module 210 , which is configured to provide code support for the functionality embedded in the GUIs of the user interface module 205 . More particularly, the controller module 210 can comprise of DWR, Dojo, and a library of JavaScript apps. The controller module 210 can be implemented using direct web remoting (DWR). DWR can be considered a Java and JavaScript open source library which allows a programmer to write Asynchronous JavaScript and XML (“Ajax”) web applications or interactive web applications. DWR allows generally JavaScript code in the GUI generated by the user interface module 205 to use Java methods.
[0027] The Dojo component can be considered an open-source JavaScript Toolkit to construct the dynamic web user interfaces. As such, the controller module 210 can dynamically generate user interfaces to pass along to the user interface module 205 for display to a user.
[0028] The library of JavaScript apps can define a list of pre-determined functionality that users are likely to call. For example, one JavaScript can be “Get Price of Product X”.
[0029] The controller module 210 can also be coupled with the broker module 215 . The broker module 215 can be configured to provide a high-level business logic for the service portal 105 . More particularly, the business logic can generally filter and direct an incoming request to the appropriate server of the service backend 130 (see FIG. 1 ). For example, the broker module 215 can receive a request for delivery terms on a selected piece of hardware. The broker module 215 can identify the server that can satisfy the request, e.g., service portal 105 , and forward the request. Similarly, a request for technical support can be identified by the broker module 215 and be forwarded to the issue tracker server 115 to be serviced.
[0030] The broker module 215 can also be coupled with model module 220 , which is configured to provide a schema for inquiries to the databases 230 . The databases 230 can, abstractly, contain two databases: a user profile database 235 and a product catalog 240 . The databases 230 can be implemented using any type of database systems provided by vendors such as MySQL, Oracle, Sybase, International Business Machines, etc. The model module 220 can provide the schema to formulate queries to pass to the databases 230 through the database interface module 225 . The model module 220 can be implemented using an open source lightweight framework such as Spring Application Framework supported by data access objects, beans, and manager.
[0031] The database interface module 225 can be configured to provide an abstraction between the databases 230 and the model module 220 . The database interface module 225 can be implemented with Hibernate or other similar abstractions. The database interface module 225 provides object relational mapping and persistence management with the databases 230 .
[0032] The modules 205 - 225 of the service portal 105 can also be implemented using be implemented using an open source servlet container and webserver such as Tomcat™ in some embodiments. Other embodiments could use proprietary servlet container and webserver technologies.
[0033] The logging module 245 can be configured to couple with the user interface module 205 , the controller module 210 , the broker module 215 , the model module 220 and the database interface module 225 . The logging module 245 can also be configured to provide logging and exception handling for all the coupled modules ( 205 - 225 ). The aforementioned module can provide functions which may be commonly called by the rest of the modules ( 205 - 225 ) of the service portal 105 . The logging module 245 can be implemented using aspect-oriented programming as known to those skilled in the art.
[0034] FIG. 3 illustrates a more detailed block diagram of the knowledge server 110 in accordance with another embodiment. It should be readily apparent to those of ordinary skill in the art that the knowledge server 110 depicted in FIG. 3 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified.
[0035] FIG. 2 and FIG. 3 share some common components. As such, the description of the common components is being omitted and the description of these components with respect to the FIG. 2 is being relied upon to provide adequate description of the common components.
[0036] As shown in FIG. 3 , the knowledge server 110 can comprise at least a user interface module 305 , a controller module 310 , a broker module 315 , a model module 320 and a database interface module 325 .
[0037] Similar to the service portal 105 , the user interface module 305 of the knowledge server 110 can be configured to provide the GUIs for users to interact with the knowledge server 110 . The functionality for selected actions by the users is provided by the controller module 310 . The controller module 310 can be configured to provide the associated code for the requested functionality of the selected action in the GUI. The broker module 315 can be configured to provide high-level business logic for the knowledge server 110 . More particularly, the broker module 315 can provide filtering for the requests entering the knowledge server 110 . For these requests, the broker module 315 can receive these requests from the service portal 105 through the server interface 335 . The server interface 330 can be implemented using simple object access protocols, web services, etc. The knowledge server 110 can also use the server interface 335 to return requested information to the service portal 105 . Unlike the service portal 105 , the knowledge server 110 can be configured to prevent direct access to the knowledge server 110 but can only be accessed through the service portal 105 .
[0038] The broker module 315 of the knowledge server 110 can also be coupled to the model module 320 , which is configured to provide a schema for queries into the knowledge database 330 . The database interface module 325 can be configured to provide a level of abstraction between the queries from the broker module 320 to the actual physical implementation of the knowledge database 330 . As previously described, the knowledge database 330 can be implemented with database architectures provided by vendors such as MySQL, Oracle, Sybase, International Business Machines, and other similar manufacturers.
[0039] The modules 305 - 325 of the service portal 105 can also be implemented using be implemented using an open source servlet container and webserver such as Tomcat™ in some embodiments. Other embodiments could use proprietary servlet container and webserver technologies.
[0040] FIG. 4 illustrates a more detailed block diagram of the issue tracker server 115 in accordance with another embodiment. It should be readily apparent to those of ordinary skill in the art that the issue tracker server 115 depicted in FIG. 4 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified.
[0041] As shown in FIG. 4 , the issue tracker server 115 can comprise of a user interface module 405 , a controller module 410 , a database interface module 415 , and a server interface 425 . Similar to the service portal 105 and the knowledge server 110 , the user interface module 405 of the issue tracker server 115 can be configured to generate GUIs for the service portal 105 to interface thereto. As with the knowledge server 110 , the service portal 105 provides a unified interface to the issue tracker server 115 . The service portal 105 can be configured to receive requests from users to access the issue tracker server 115 . The received requests are processed by the issue tracker server 115 and any information is returned using the issue tracker server's GUIs as generated by the user interface module 405 . The service portal 105 reformats any returning information from the issue tracker server 115 and the other servers in a unified GUI generated by the user interface module 205 of the service portal 105 . In some instances, the service portal 105 can generate an overlay for data arriving from the other servers ( 110 - 120 ). Accordingly, a user can be presented with information in a consistent format.
[0042] The user interface module 405 can be implemented using HTML code, CSS sheets, Hyptext Pre-Processor (“PHP”) code and/or Ruby on Rails (ROR) code. The controller module 410 can provide the associated code for the functionality provided by the GUIs generated by the user interface module 405 .
[0043] The controller module 410 can be configured to communicate with the service portal 105 , the knowledge server 110 and the chat server through a communication interface 425 . The communication interface 425 can use SOAP or web service protocols over the Internet to provide the communication conduit.
[0044] The controller module 410 can also be configured to interface with the database 420 . The database 420 can be configured to store the open and closed service tickets. The database 420 can also be configured to store links to or the actual articles and/or chats sessions used to resolve the issue. In some embodiments, the database 420 can be implemented using MySQL 5.x database or other open source database. Other embodiments, the database 420 can be implemented proprietary databases such as Oracle, Sybase, IBM, etc.
[0045] Although FIG. 4 depicts the user interface module 405 , controller module 410 , and the database interface module 415 as separate components, these modules ( 405 - 415 ) can be implemented using LAMP, which is an open source Web development platform based on Linux, Apache, MYSQL, and PHP.
[0046] FIG. 5 illustrates a more detailed block diagram of the chat server 120 in accordance with another embodiment. It should be readily apparent to those of ordinary skill in the art that the chat server 120 depicted in FIG. 5 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified.
[0047] The chat server 120 can be configured to provide chat services for users. The chat server 120 can provide a communication link between users and a group of support personnel. The chat server 120 , can also provide a communication link between users of the service portal. The users can request access to support through a GUI of the service portal 105 . Some embodiments can use Openfire to provide group and instant messaging service using the Extensible Messaging and Presence Protocol (“XMPP”).
[0048] As shown in FIG. 5 , the chat server 120 can comprise a user interface module 505 , a controller module 510 , a database interface module 515 and a database 520 . The user interface module 505 of the chat server 120 can be configured to generate GUIs for the service portal 105 to interface thereto. The user interface module 505 can be implemented using HTML code, CSS, and/or Java Server pages.
[0049] As with the knowledge server 110 and the issue tracker server 115 , the service portal 105 provides a unified interface to the chat server 120 . The service portal 105 can be configured to receive requests from users to access the chat server 115 . The received requests are processed by the chat server 120 to start a chat session with someone from a group of technical support personnel.
[0050] The received requests for chats can be processed by the controller module 510 , which contains the associated code for the selected function in the GUI by a user. The controller module 510 , in some embodiments, can be implemented using DWR.
[0051] The controller module 510 can also interface with a database interface module 515 . The database interface module 515 can be configured to translate queries from the controller module 510 to appropriate format of the database 520 to store and retrieve information. The information stored in the database 520 can comprise of chat sessions between users and support personnel. In some embodiments, the database 520 can be implemented with a MySQL database. Returning to the database interface module 515 , this module 515 can be implemented using plain old Java objects as known to those skilled in the art.
[0052] Although FIG. 5 depicts the user interface module 505 , controller module 510 , and the database interface module 515 as separate components, other embodiments can implement the functionality of these modules can be implemented using Tomcat Servlet container and web server from Apache Software Foundation.
[0053] Returning to FIG. 3 , the knowledge server 110 can be configured with a tagging module 340 embedded in the controller module 310 . The tagging module 340 can be configured to permit the user community of the service portal 105 to tag items in the knowledgebase. More particularly, the tagging module 340 can be configured to provide a predefined set of tags as well as a community set of tags. The predefined set of tags can be developed from the community set of tags by a group of users with super privileges (such as support personnel, verified experts, etc.). An example of the predefined set of tags can be a support-team tags. These tags would be used by the support personnel to tag items in the knowledgebase that are helpful, authoritative, or other high value. Accordingly, the predefined set of tags are given much more weight.
[0054] These users can apply the predefined set of tags to knowledgebase items, where the knowledgebase items can be articles, posts, or other similar information useful to the user community. Ordinary users can apply tags to knowledgebase items based on a community set of tags, where the community set of tags can be any term supplied by an ordinary user. The community set of tags can also be configured to show the popularity of any tag within the set. Accordingly, a subsequent user can search the knowledgebase based on the predefined set of tags, the community set of tags, or a combination of the two tag sets. The subsequent user can also narrow the search by determining the popularity of tag terms within the community set of tags.
[0055] FIG. 6 illustrates a block diagram of the tagging module 340 in accordance with yet another embodiment. It should be readily apparent to those of ordinary skill in the art that the tagging module 340 depicted in FIG. 6 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified.
[0056] As depicted in FIG. 6 , the tagging module 340 comprises of a manager module 605 and a memory 610 . The manager module 605 is configured to implement the functionality of the tagging module 340 as previously described and described in greater detail below with respect to FIGS. 7-8 . The manager module 605 can be implemented in software code (Java, C, C++, etc.), hardware device (application specific integrated circuit, field programmable gate array, microprocessor, etc.) or combination thereof.
[0057] The manager module 605 can also be configured the memory 610 . The memory 610 can store a set of community tag terms 615 as well as a predefined set of tag terms 620 . The set of community tag terms 615 can be developed by the users of the community interfacing with the service portal 105 . The users can freely add additional tags to the set of community tag terms 615 .
[0058] The predefined set of tag terms 620 can be derived from the set of community tag terms 615 approved from the group of users with super privileges (such as support personnel, verified experts, etc.). Moreover, this group of users can only be permitted to add additional tag terms to the predefined set of tag terms 620 .
[0059] A user can view the popularity of a term in the set of community tag terms 615 . More particularly, a user, through a GUI of the service portal 105 , can view the list of terms in the set of community tag terms 615 . The service portal 105 formulates a request to the knowledge server 110 , which then returns the requested information to the service portal 105 . The requested information is presented in a list showing the popularity of each term in the set of community tag terms 615 by font size in some embodiments, i.e., the more popular the term, the larger the font.
[0060] FIG. 7 illustrates a flow diagram 700 implemented by the tagging module 340 . It should be readily apparent to those of ordinary skill in the art that the flow diagram 700 depicted in FIG. 7 represents a generalized schematic illustration and that other steps may be added or existing steps may be removed or modified.
[0061] As shown in FIG. 7 , a user can be reviewing a knowledgebase item, in step 705 . More particularly, the user may have accessed the service portal 105 through their local computer via a web browser such as Opera, Mozilla, Internet Explorer, or other similar web browser applications. The service portal 105 presented a GUI for the user to search for items in the knowledgebase. The service portal 105 can be configured to process the request for the selected query to the controller module 215 of the service portal 105 and forward the request to the knowledge server 110 through the server interface 335 . The knowledge server 110 can be configured to process the request through the broker module 315 of the knowledge server 315 , which passes the request through the model module 320 and database interface module 325 . The items matching the request are returned form the database 330 and possibly other third-party source can then be returned to the service portal 105 .
[0062] In step 710 , the user can tag a knowledge item with a tag term from either the set of community tag terms 615 and the predefined set of tags. More particularly, after reviewing a knowledge item, the user can select at least one term from either one of both the set of community tag terms 615 and the predefined set of tag terms 620 that the user would like to associate with the knowledge item. As previously mentioned, the knowledge item can be an article, a FAQ, a Wiki page or other written description. Multiple tag terms can be associated with the knowledge item.
[0063] In step 715 , the tagging module 340 can be configured to associate the selected tag terms with the knowledge item. More particularly, the selected tag terms become part of the metadata associated with the knowledge item. Accordingly, subsequent users can search for the knowledge item based on the associated tags as well as search terms within the knowledge item.
[0064] In step 720 , the tagging module 340 can be configured to store the knowledge item with the associated tags within the database 330 to be searched by subsequent users of the service portal 105 .
[0065] FIG. 8 illustrates a flow diagram 800 implemented by the tagging module 340 in accordance with yet another embodiment. It should be readily apparent to those of ordinary skill in the art that the flow diagram 800 depicted in FIG. 8 represents a generalized schematic illustration and that other steps may be added or existing steps may be removed or modified.
[0066] As shown in FIG. 8 , in step 805 , a user can enter search terms in a GUI generated by a service portal 105 to search for items in the knowledge server 110 , i.e., search the knowledgebase. The user can enter terms from the set of community of tag terms 615 and/or the predefined set of tag terms 620 to search for information items from the knowledge server 110 onto the selected GUI.
[0067] The controller module 210 of the service portal 105 can be configured to format a request packet to the knowledge server 110 , which is passed to the broker module 210 through the server interface 335 and the broker module 315 of the knowledge server 110 .
[0068] The broker module 315 of the knowledge server 110 can be configured to formulate a query based on the model module 320 to pass the database 330 through the database interface module 325 , in step 810 . In some embodiments, the knowledge server 110 can be configured to work with third party web sites with the selected tag terms. The third party web site results can be grouped and ranked with the results from the knowledge server 110 , in step 815 .
[0069] In step 820 , the broker module 315 of the knowledge server 110 can forward the search results in a ranked fashion. More particularly, the list of results can be ordered by the popularity of the tag terms associated with each result, a ranking or rating associated with each result or other criteria. Since items tagged with the tag terms from the predefined set of tag terms 620 are given more weight, these items are ranked higher and should float to the top of the results list. The results are passed onto to the service portal 105 where the results are displayed by another GUI generated by the controller module 210 of the service portal 105 .
[0070] Certain embodiments may be performed as a computer program. The computer program may exist in a variety of forms both active and inactive. For example, the computer program can exist as software program(s) comprised of program instructions in source code, object code, executable code or other formats; firmware program(s); or hardware description language (HDL) files. Any of the above can be embodied on a computer readable medium, which include storage devices and signals, in compressed or uncompressed form. Exemplary computer readable storage devices include conventional computer system RAM (random access memory), ROM (read-only memory), EPROM (erasable, programmable ROM), EEPROM (electrically erasable, programmable ROM), and magnetic or optical disks or tapes. Exemplary computer readable signals, whether modulated using a carrier or not, are signals that a computer system hosting or running the present invention can be configured to access, including signals downloaded through the Internet or other networks. Concrete examples of the foregoing include distribution of executable software program(s) of the computer program on a CD-ROM or via Internet download. In a sense, the Internet itself, as an abstract entity, is a computer readable medium. The same is true of computer networks in general.
[0071] While the invention has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments without departing from the true spirit and scope. The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. In particular, although the method has been described by examples, the steps of the method may be performed in a different order than illustrated or simultaneously. Those skilled in the art will recognize that these and other variations are possible within the spirit and scope as defined in the following claims and their equivalents. | An embodiment relates generally to a method of organizing information. The method includes providing for a knowledgebase and providing for a first set of tags configured to be applied to items in the knowledgebase. The method also includes providing for a second set of tags configured to be applied to items in the knowledgebase and searching the knowledgebase based on at least one of the first set of tags and the second set of tags. The method further includes ranking result items in a search result favoring the result items tagged with terms for the first set of tags. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to a heat exchanger comprising a plurality of flat tubes for heat exchange between a first fluid inside said tubes and a second fluid flowing outside of said tubes, a pair of hollow headers connected to the ends of the flat tubes, an inlet and an outlet being provided in the headers for introducing the first fluid into the tubes and discharging it therefrom, each header being composed of at least two parallel tubes with circular cross-sections two adjacent tubes having common wall portions and all tubes of each header constituting a substantially flat array of tubes.
Such a heat exchanger is known from EP-A-0 608 439.
In conventional heat exchangers, such as e.g. disclosed in EP-A-0 359 358, the header consists of a tube with circular cross-section. These tubes have been provided with holes with a shape corresponding to the cross-section of the heat transfer tubes so as to accept the tube ends. This design proves to be very satisfactory with the traditional pressures used in this type of heat exchanger. Commonly at the low pressure side a pressure of 2,5-6 bar has been used, whereas at the high pressure side pressures between 15 and 30 bar are used. With the introduction of higher pressures, the wall thickness of the header has to be increased. This is especially true for heat exchangers using CO 2 at high pressure, where the low pressure is between 35-80 bar and the high pressure between 80 and 170 bar.
This increase in size of the headers has resulted in heat exchangers with large size and weight, which constitutes especially a disadvantage in heat exchanger to be used in mobile equipment such as passenger cars and the like.
The problem with respect to the strength of the header has been overcome by constructing the header as disclosed in EP-A-0 608 439.
In this header a number of parallel tubes has been provided each communicating with a number of heat exchanging tubes. A parallel flow is occurring between the different tubes of the header and the different heat exchanging tubes. A disadvantage of this system is that the pressure drops and therefor the flow patterns in the different available flow paths are all different. This leads to additional losses in pressure and irregularities in the flow which negatively influences the heat exchange.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a heal: exchanger which does not show the disadvantages mentioned above.
This and other objects are achieved in that a number of holes each with a dimension corresponding to the cross-sections of the flat tube is made in the flat surface of each header, and in that the ends of the flat tubes are only inserted in so far into the circular tubes that a communication passage is left between the parallel tubes constituting the header.
BRIEF DESCRIPTION OF THE DRAWINGS
In this way it becomes possible to ensure a cross-flow between the different flat tubes whereby the pressure between the different flow paths is equalised as will as the flow pattern.
FIG. 1 is schematic view of a heat exchanger according to the invention,
FIG. 2 is a cross-section according to the line II--II of the header, shown in FIG. 1,
FIG. 3 is a front view of the header used in the heat exchanger of FIG. 1,
FIG. 4 is a side view of the header of FIG. 3 and
FIG. 5 a front view of the header on enlarged scale according to FIG. 3, showing one hole in more detail.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 to 4, the illustrated heat exchanger includes a plurality of flat heat transfer tubes 1 stacked in parallel and corrugated fins 2 sandwiched between the flat tubes 1. The ends 1a of the tubes 1 are connected to headers 3 and 4. Each heat transfer tube may be made of extruded aluminium, having a flat configuration. Alternatively, the flat tubes can be multi-bored flat tubes, commonly called multiport tubes or else, electrically seamed tubes can be used. Multiport tubes may be made by extrusion, but otherwise it is possible to make such tubes by rolling from clad sheet, folding and brazing. Furthermore, it is possible to use a welded tube with an inserted baffle.
In the embodiment shown each corrugated fin 2 has a width approximately similar to that of the flat tube 1 but other widths may be used as well. The fins 2 and the flat tubes 1 are brazed to each other. The headers 3,4 are made up of aluminium tubes with holes 5 of the same shape as the cross-section of the heat transfer tubes 1 so as to accept the tube ends 1a. The holes 5 can also be tailor made, e.g. conical, so as to allow easier access for the flat tubes. The inserted tube ends la are brazed in the holes 5. As shown in FIG. 1, the headers 3 and 4 are connected to an inlet manifold 6 and an outlet for the flat tubes. The inserted tube ends la are brazed in the holes 5. As shown in FIG. 1, the headers 3 and 4 are connected to an inlet manifold 6 and an outlet manifold 7, respectively. The inlet manifold 6 allows a heat exchanging fluid to enter the header 3, and the outlet manifold 7 allows the heat exchanging fluid to discharge. The headers 3 and 4 are closed with caps or plugs 8 and 9, respectively. The reference numerals 13 and 14 denote side plates attached to the outermost corrugated fins 2.
The header 3 has its inner space divided by a baffle 10 into two sections, and the header 4 is divided into two sections a baffle 11. In this way a medium path is provided starting from header 3, passing through a first set of tubes 1, through part of the header 4, passing through a second set of tubes 1 to header 3 and passing through a third set of tubes 1 to header 4 and to leave the heat exchanger unit through outlet 7. It is clear that these headers without baffles are also possible and otherwise headers with more than one baffle per header can be applied as well.
The heat exchanging fluid flows in zigzag patterns throughout the heat exchanger unit.
The headers 3 and 4 are basicly identical and in the FIGS. 2-4 an example of a header 3 is shown in more detail. The header 3 consists in fact of a multiple port extruded tube and in the example shown four channels 16, 17, 18 and 19 are present. It is however clear that any number of channels may be present. The header 3 can be seen as being a number of tubes each forming one of the channels 16, 17, 18 and 19 and having wall portions 20, 21 and 22 which are common to two of these tubes. So the wall portion 20 is common for tubes forming the channels 16 and 17, the wall portion 21 for the tubes forming the channels 17 and 18 and the wall portion 22 for the tubes forming the channels 18 and 19. The wall portions 24 and 25 of the tubes which are more ore less perpendicular to the common wall portions 20, 21 and 22 are substantially in one plane and thereby form a substantially flat surface.
As more clearly shown in the FIGS. 3 and 4, the wall portion 24 of the header 3 is provided with a number of holes 5. These holes 5 have a cross-section which substantially correspond to outer-dimensions and shape of the cross-section of the flat tubes 1. These holes can be obtained by means of serrations or cut-outs. As shown in FIG. 2 these holes extend to a defined depth reaching the common wall portions 20, 21 and 22 where they end in a common flat surface 31. The end portions 1a of the tubes 1 can be inserted to that depth into the holes 5 and can be connected to the header 3 by one of the commonly known methods such as brazing. In this way a fluid connection can be obtained between the header 3 and the individual tubes 1. Preferably each hole is made with increased depth by adding material to the header.
In case the tube ends 1a of a multiple port extrusion tube are fully inserted up to the level of the surface 31 into the header 2, a number of channels of this multiple port extrusion tube are blocked by the wall portions 20, 21 and 22 and are not effective in the heat transfer process. It is possible to use a number of multiple port extrusion tubes fitting into each cut-out in front of the open part of the channels 16, 17, 18 and 19. As a rule this is cumbersome and preference is given to an obstruction of the channels in the multiple port heat transfer tube 1 which are opposite the wall portions 20, 21 and 22. Alternatively it is possible to increase the depth of the holes 5 up to the level of the surface indicated by 32. If the tubes 1 are now inserted up to the level of the surface 31 and fixed in that position a connection is obtained between the different channels 16, 17, 18 and 19 in the header 3. This may equalize the pressure and flow pattern between the different channels.
In order to facilitate the assembling and as shown in FIG. 5, it is possible to make the holes 5 in two stages. In a first stage the hole 5 is made on full width i.e. the thickness of the flat tubes 1, up to the level of surface 31. In a second stage the holes are made deeper on a reduced width i.e. appoximately the thickness of the flat tubes minus twice the wall thickness, up to the level of surface 32. As shown in FIG. 5 in this way a number of shoulders 33 is made in the header holes, allowing the tubes ends 1a to be inserted up till the level of surface 31 and being connected to the header, thereby having an open communication between the different channels of the header 3 or 4, and thus allowing a better cross-flow pattern between the channels.
The shoulders 33 have a defined length corresponding to the thickness of common wall 20, 21 or 22 between the different channels of the header 3 or 4, as seen in FIGS. 2 and 5. In case of connecting the tubes 1 with the headers 3 or 4 be means of brazing, it is possible that part of the brazing material is flowing on the surface of the shoulder 33 and into the inner channel of the tubes 1. In order to avoid this in-flow of brazing material it is possible to reduce the length of the shoulders to such an extent that only a very small portion of shoulder 33 is in contact with the tube end 1a.
It is clear that the invention is not restricted to the example described above but that modifications are possible within the same inventive concept which fall within the scope of the annexed claims. More especially it is possible to use two different headers, one with the tubes 1 fully inserted and one with the tubes 1 partially inserted in order to have the internal communication. | A heat exchanger comprises a plurality of flat tubes for heat exchange between a first fluid flowing inside the tubes and a second fluid flowing outside the tubes. A pair of hollow headers is connected to the ends of the flat tubes. An inlet and outlet are provided in the headers for introducing the first fluid into the flat tubes and discharging it therefrom. Each header is composed of at least two parallel tubes with substantially circular cross-section, two adjacent tubes having integrated wall portions, thereby providing a substantially flat header. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to a miniature light-emitting diode (LED) device and more specifically to a miniature LED-light emitting device which is waterproof and therefore can be used in environments in which it will be exposed to water.
BACKGROUND OF THE INVENTION
A typical miniature LED device includes a metal cylinder in which an LED and batteries for providing power thereto are received. The cylinder includes opposite axial parts whereby one axial part has a tubular part with an internal thread while the other axial part has a smaller diameter tubular part with an external thread engageable with the internal thread, with the cooperating threads allowing relative rotation between the axial parts. Illumination of the LED is controlled by rotating one axial part of the metal cylinder relative to the other axial part which regulates the formation or interruption of a circuit between the LED and the batteries.
To enable the relative rotation of one axial part of the metal cylinder relative to the other, a space must be maintained between opposed edges of the axial parts. This space is defined between edges of the axial parts which are substantially perpendicular to and alongside the threads. As the axial parts are rotated relative to one another, the dimensions of this space vary.
A particular problem with such miniature LED devices is that when the LED devices are exposed to water, the water can enter into the space between the opposed edges of the axial parts. From this space, the water can seep between the threads into the interior of the LED device and interrupt the circuit between the LED and the batteries, i.e., cause a short-circuit. Once this happens, the LED device is rendered useless. In view of this problem, such miniature LED devices are often not used in environments in which water is likely to be present.
Another problem with such miniature LED devices is that one of the axial parts might be inadvertently rotated relative to the other thereby turning the LED on or off when set in either position, i.e., the inadvertent rotation might turn the LED off when the device is set in the on position or turn the LED on when the device is set in the off position.
It would therefore be desirable to have an LED device which is waterproof and can be used in all environments including those in which it will be exposed to water, and also an LED device which can be maintained in its set position without allowing inadvertent rotation of the axial parts relative to one another.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a new and improved miniature LED device which is waterproof.
It is another object of the present invention to provide a new and improved miniature LED device which allows for two axial parts to be rotatable relative to one another to enable control of illumination of the LED via such rotation while preventing entry of water into a space between the axial parts necessary to allow such rotation.
It is yet another object of the present invention to provide a new and improved miniature LED device which can be maintained in its set position without allowing inadvertent rotation of the axial parts relative to one another to cause the set position to change.
In order to achieve these objects and others, a miniature light-emitting diode (LED) device in accordance with the invention includes a cylinder including a first housing part having an internal thread and a second housing part having an external thread and rotatably coupled to the first housing part via engagement of the threads, an LED light assembly arranged in connection with the cylinder and a dome connected to the cylinder in a position covering the LED light assembly. The cylinder defines a chamber in which one or more batteries are received. At least a portion of each housing part is conductive to enable formation of an electrical circuit including the battery or batteries, the LED light assembly and the conductive portions of the housing parts. Illumination provided by the LED light assembly is controlled by rotating the housing parts relative to one another causing formation or interruption of the electrical circuit.
The device also includes an elastic ring or similar structure which covers a space between the housing parts and alongside the threads to prevent water from entering between the threads into the interior of the cylinder and interrupting the electrical circuit. The device is thereby rendered waterproof and can be used in environments where water is present.
Furthermore, in view of a friction fit of the elastic ring to both housing parts, it prevents inadvertent movement of the housing parts relative to one another to thereby prevent inadvertent changing of the on or off status of the device. The device's status can therefore be reliably maintained.
In one embodiment, the dome is faceted to provide better light distribution and a distinctive illumination when the LED light assembly is operative. A faceted dome can be used independent of the elastic ring or other structure which prevents water from entering between the threads, i.e., the invention contemplates an embodiment wherein the device includes a faceted dome but does not include the elastic ring.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals identify like elements, and wherein:
FIG. 1 is a perspective view showing a miniature LED device in accordance with the invention.
FIG. 2 is a front elevational view of the miniature LED device in accordance with the invention.
FIG. 3 is an end view of a faceted dome of the miniature LED device in accordance with the invention.
FIG. 4 is a cross-sectional side view taken along the line 4 - 4 of FIG. 2 .
FIG. 5 is an exploded perspective view of the miniature LED device in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the accompanying drawings wherein like reference numerals refer to the same or similar elements, a miniature LED device 10 in accordance with the invention includes a cylinder 12 having a bottom housing part 14 and a top housing 16 , a faceted dome 18 coupled to the top housing part 16 , an elastic ring 20 arranged around the cylinder 12 , batteries 22 housed in a chamber defined in the cylinder 12 and an LED light assembly 24 arranged in connection with the cylinder 12 . In the convention used herein, the bottom of the device 10 is considered the leftmost part of the device 10 as shown in the drawings whereas the top of the device 10 is considered the rightmost part of the device 10 as shown in the drawings.
Both bottom and top housing parts 14 , 16 are made at least partially of an electrically conductive material such as metal to enable completion of an electric circuit including the batteries 22 and the LED light assembly 24 . Additional details of the formation of this circuit are described below.
Bottom housing part 14 includes a circular base 26 , a tubular part 28 extending upward from the periphery of the base 26 , an internal thread 30 formed on an inner surface of the tubular part 28 , a contact button 32 arranged on the base 26 inside of the tubular part 28 and a through ring 34 extending downward from the base 26 . Through ring 34 enables the device 10 to connect to holding means such as a hook, string or wire for hanging the device 10 .
Top housing part 16 includes a first tubular part 36 , a second, smaller diameter tubular part 38 extending downward from the first tubular part 36 , an external thread 40 formed on the second tubular part 38 and a cylindrical recess 42 at an upper region. The faceted dome 18 is secured to the first tubular part 36 and extends partially into the cylindrical recess 42 . Top housing part 16 also includes an inner flange 44 .
As shown in FIG. 4 , there is an annular space 46 between a bottom-facing surface 48 of the top housing part 16 at the edge of the first tubular part 36 and a top-facing surface 50 of the tubular part 28 of the bottom housing part 14 . Space 46 is alongside the threads 30 , 40 and its size varies upon rotation of the bottom and top housing parts 14 , 16 relative to one another. The bottom-facing surface 48 is part of an annular step between the first and second tubular parts 36 , 38 which is formed in view of the different diameters of the first and second tubular parts 36 , 38 . The presence of this space 46 enables relative rotation of the bottom and top housing parts 14 , 16 to control power supply to the LED light assembly 24 , explained in detail below.
To prevent water from entering into the interior of the LED device 10 through space 46 and between the cooperating threads 30 , 40 , elastic ring 20 is slid onto the cylinder 12 to a position in which it covers or surrounds the space 46 and extends a small distance below the space 46 and a small distance above the space 46 (see FIG. 4 ). Elastic ring 20 has a substantially tubular form and maybe made of rubber.
The diameter of the elastic ring 20 is selected to provide a friction fit against the outer surfaces of the bottom and top housing parts 14 , 16 and thereby form a water-tight seal which prevents water from entering into the space 46 . However, the diameter of the elastic ring 20 is also dimensioned so that it is not overly tight against the bottom and top housing parts 14 , 16 because it is necessary to maintain the ability to rotate the bottom and top housing parts 14 , 16 relative to one another. Nevertheless, if the elastic ring 20 is designed to provide a very tight seal which hinders rotation of the bottom and top housing parts 14 , 16 relative to one another, the elastic ring 20 could be slid up or down to a position entirely on one of the housing parts 14 , 16 so that the housing parts 14 , 16 can then be rotated relative to one another.
Another advantage obtained by the presence of elastic ring 20 in contact with both bottom and top housing parts 14 , 16 is that inadvertent rotation of the housing parts 14 , 16 relative to one another is prevented in view of the friction fit between the elastic ring 20 and the bottom and top housings parts 14 , 16 . As such, the LED device 10 can be reliably maintained in an on or off position without concern that inadvertent rotation will change this status.
To ensure a water-tight environment in the cylinder 12 , the tubular part 28 of the bottom housing part 14 and the first tubular part 36 of the top housing part 16 do not include any uncovered openings on their outer surfaces. For example, there is no uncovered opening in either tubular part for an activation strip which is often provided in prior art miniature LED devices to separate the batteries from an electrical contact in order to prolong battery life by initiating operation only after the activation strip is removed. The presence of an uncovered opening for an activation strip would allow water to enter into the interior of the cylinder. If it is desired to provide such an activation strip in the LED device in accordance with the invention and an opening therefor is required, the opening for the activation strip can be formed in close proximity to the space 46 between the bottom and top housings parts 14 , 16 so that the opening is covered by the elastic ring 20 .
Additional protection against water seeping into the interior of the cylinder 12 is provided by securing the faceted dome 18 to the first tubular part 36 of the top housing part 16 in a water-tight matter. As such, water cannot seep into the interior of the cylinder 12 between the top housing part 16 and the faceted dome 18 .
LED light assembly 24 includes a substantially planar printed circuit board 52 having a first electrical contact 54 on a lower surface which engages with the positive terminal of the uppermost one of the batteries 22 and a second electrical contact 56 on an upper surface which engages with the flange 44 of the top housing part 16 . A light-emitting diode (LED) 58 is mounted to the upper surface of the printed circuit board 52 via a pair of electrical contacts 60 (see FIG. 5 ). When arranged in the top housing part 16 , the printed circuit board 52 of the LED light assembly 24 is below the flange 44 , the LED 58 is above the flange 44 and the contacts 60 extend through an opening defined by the flange 44 (see FIG. 4 ).
When the bottom and top housing parts 14 , 16 are engaged with one another via the cooperating threads 30 , 40 , they can be rotated in one direction relative to one another to cause the contact button 32 to contact the negative terminal of the lowermost one of the batteries 22 and urge the positive terminal of the uppermost one of the batteries 22 against the first electrical contact 54 . At the same time, the second electrical contact 56 is urged against the flange 44 . In this state, shown in FIG. 4 , an electrical circuit is completed from the negative terminal of the lowermost one of the batteries 22 , through the contact button 32 on the bottom housing part 14 , through the bottom and top housing parts 14 , 16 to the second electrical contact 56 of the printed circuit board 52 , through wiring on the printed circuit board 52 and one electrical contact 60 to the LED 58 , through the other electrical contact 60 connected to the LED 58 to the printed circuit board 52 and through wiring on the printed circuit board 52 to the first electrical contact 54 in contact with the positive terminal of the uppermost one of the batteries 22 . As such, rotation of the bottom and top housing parts 14 , 16 relative to one another controls illumination of the LED 58 in that it selectively brings the contact button 32 into or out of contact with the negative terminal of the lowermost one of the batteries 22 to form or interrupt the electrical circuit between the batteries 22 and the LED light assembly 24 .
Bottom and top housings parts 14 , 16 may be made entirely of a conductive material or only partly of conductive material. It will suffice that only a portion of the bottom and top housing parts 14 , 16 which establishes a conductive path from the contact button 32 to the surface of the top housing part 16 being contacted by the second electrical contact 56 is made of conductive material.
LED device 10 also includes a sleeve 62 , preferably made of plastic or another non-conductive material, which surrounds the batteries 22 , i.e., the sleeve 62 is positioned substantially between the circumferential edges of the batteries 22 and an inner cylindrical surface of the top housing part 16 . Sleeve 62 electrically isolates the batteries from the top housing part 16 .
LED device 10 also includes a resilient washer 64 made of, for example, rubber which surrounds the positive terminal of the uppermost one of the batteries 22 (see FIG. 5 ).
The faceted dome 18 has a plurality of flat surfaces 66 so that light emitted from the LED 58 is better distributed and also includes with a distinctive illumination pattern.
Instead of the elastic ring 20 , it is possible to use an O-ring which is placed into the space 46 between the bottom-facing surface 48 of the top housing part 16 and the top-facing surface 50 of the tubular part 28 of the bottom housing part 14 . Such an O-ring would prevent water from entering into the interior of the device 10 between the threads 30 , 40 .
As another alternative to the elastic ring 20 , any member which is arranged to cover the space 46 and/or in the space 46 and prevents water from entering between the threads 30 , 40 can be used in the invention.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. For example, although the illustrated embodiment includes three batteries, it is possible to use any number of batteries including only a single battery. | Waterproof miniature LED device including a cylinder having a first housing part with an internal thread and a second housing part with an external thread and rotatably coupled to the first housing part via engagement of the threads, an LED light assembly mounted to the cylinder and a dome connected to the cylinder and covering the LED light assembly. The cylinder defines a chamber for receiving batteries. Each housing part is conductive to enable formation of an electrical circuit including the batteries, LED light assembly and conductive portions of the housing parts. Illumination provided by the LED light assembly is controlled by rotating the housing parts relative to one another causing formation or interruption of the electrical circuit. An elastic ring covers a space between the housing parts alongside the threads to prevent water from entering between the threads into the interior of the cylinder and interrupting the electrical circuit. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of PCT/DE2006/000375 filed on Feb. 24, 2006; DE 10 2005 010 250.6 filed on Feb. 25, 2005; and, DE 10 2005 040 597.5 filed on Aug. 17, 2005, the entire contents of which are hereby incorporated in total by reference.
BACKGROUND OF THE INVENTION
This invention relates to a method and a device for tracking sweet spots of a sweet spot unit used in a transmissive electronic display for displaying information, said method and device imaging light after modulation with the information by the display in a directed manner on to observer eyes of at least one observer in sweet spots.
This invention can be applied in monoscopic and/or autostereoscopic displays for one or multiple observers. A display device according to this invention allows images to be displayed optionally in a two-dimensional, in a three-dimensional mode or in a mixed mode. In this document, the term “autostereoscopic display” denotes a display device using which at least one observer can view three-dimensional images without any additional aids from a large number of positions to be chosen freely by the observer.
Seen in the direction of light propagation, the sweet spot unit of a display comprises an illumination matrix with a multitude of illumination elements which emit or transmit light, and imaging means with imaging elements. The imaging means image the light of activated illumination elements of the illumination matrix on to the eyes of at least one observer in the form of one or multiple sweet spots in more or less ideal bundles of parallel rays. For this, a multitude of illumination elements are assigned to each imaging element of the imaging means. Sweet spots are regions in which information provided on the information panel can be viewed at high quality.
The homogeneity of the information displayed on the information panel must be ensured in the sweet spots at all times, and cross talk of information among the eyes of an observer must be prevented when viewing three-dimensional contents. These conditions must continue to be fulfilled if the observer changes their position in the space in front of the display device, so that the observer is continuously provided with high-quality monoscopic or stereoscopic image contents. For example, in a monoscopic display used in a vehicle the driver is shown a route map while a passenger can watch a movie. Both persons should be able to move in a certain range without losing their specific information.
Further, it has been shown that disturbances and imaging defects are likely to occur already if the number of light sources activated for a defined sweet spot is only slightly too small or too large. For example, observers may experience cross talk between individual sweet spots, and the image quality, for example homogeneity and contrast, may deteriorate. The human eye perceives such changes very easily.
Autostereoscopic displays are expected to present high-quality three-dimensional scenes, but also to exhibit properties which are irrespective of the number of observers, such as free and independent mobility of observers and optional access to multiple representations in a two-dimensional and/or three-dimensional mode.
In order to be able to fulfil all those requirements to an optimal degree, a suitable tracking system will be necessary which provides information for subsequent processing in tracking devices and for stereoscopic display of information. Such a tracking system must be capable of continuously detecting observer movements in front of the display device in a viewing space which is as large as possible, so that each observer is always provided with their specific image information irrespective of their actual position. This makes great demands on the accuracy of the position finders, on the quality of individual elements of the display and on the imaging quality of the display as a whole.
There are tracking systems which use mechanical, optical and other means, or combinations thereof, for tracking. However, these systems suffer from disadvantages which adversely affect their accuracy or suitability in real-time applications. Their design is often voluminous, and the viewing space in which the observers can be provided with information is very limited. Moreover, the required computing time increases considerably the more factors are to be considered in the process from position detection to information provision.
The document WO 03/053072 A1 discloses a multi-user display with a tracking system which collects three-dimensional position information and with sequential presentation of stereoscopic images. The display comprises, one after another, a backlight which can be addressed three-dimensionally, a large-area imaging lens for focusing light on the observer and a light modulator as an image matrix. The backlight is composed of a multitude of two-dimensional light source arrays which are disposed one behind another in a multitude of planes. Illumination elements in one of the light source arrays of the backlight are determined for activation according to the actual observer position. This method also allows light source tracking with respect to the distance between one or multiple observers and the display. Three-dimensional position information of all observer eyes are detected dynamically, assignable illumination elements of the backlight are opened, and bundles of rays are focused on the respective right/left observer eyes in synchronism with the modulated images.
The disadvantage of this display device is its low brightness, because only the light of one locally selectable point light source is available for illuminating the entire image per observer eye, and because the inactive light source arrays in the optical path absorb part of this light. In addition to its voluminous design, this three-dimensional backlight is difficult to manufacture.
The document U.S. Pat. No. 6,014,164 describes an autostereoscopic display for multiple observers with a light source tracking system. Light sources, which are arranged in pairs per observer, can be moved in x, y and z direction such to track the changing positions of the observers with the help of a control system. This method allows to continuously providing the observers sequentially with three-dimensional scenes on the information panel. The disadvantages described above also apply to this system because it also employs the method of light source tracking. In particular, expensive tracking means are required, because the observer-specific light source pairs must be tracked individually for each observer. These means do not allow a flat design of the display device to be achieved.
Prior art tracking methods are only able to deliver specific information to observers who are situated at various positions in a stereoscopic viewing space with considerable restrictions. The tracking range and brightness of the image matrix are limited. Moreover, the displays are voluminous and require expensive means, including computing means, to realise the tracking. The more observers are situated at various positions in front of the display, the greater becomes the volume of data to be calculated and, consequently, the more increases the delay between position detection and actual provision of sweet spots. It has thus become common practice not to calculate a certain part of the data in real time, but to store pre-calculated data in a look-up table, and to call up and to process such data as required. Another drawback is the fact that the storage capacity of the system will be exhausted quickly as the number of observers rises.
SUMMARY OF THE INVENTION
It is an object of the present invention to prevent or to minimise the disadvantages of prior art solutions mentioned above with the help of the inverse ray tracing method. The inverse ray tracing method used here determines the propagation of light based on the geometrical arrangement of optical components. It takes advantage of the property of light that optical paths are reversible, so that all rays can be traced back from the eye to the point where they originated.
Specifically, it is an object of this invention to provide displays with a sweet spot unit with a possibility of quick non-mechanical tracking of extended sweet spots according to the change of observer positions in a relatively large viewing space and to deliver to the individual sweet spot locations observer-specific image information displayed in an image matrix while maintaining a continuously high imaging quality and homogeneous illumination of the information panel.
At the same time, the tracking range is to be increased and the specific images for each observer are to be kept free from cross talk. Further, the volume of data to be calculated in real time for a tracking method is to be minimised and the volume of pre-calculated data stored in a look-up table is to be kept as low as possible while ensuring an acceptable computing time.
It is a known fact that scattering and diffraction of optical components in the optical path largely affect the imaging quality and thus the homogeneous illumination of the sweet spots. Scattering and diffraction may be directed in a horizontal or vertical plane or in all planes by choosing certain optical components. Using scattering and diffraction means purposefully, the homogeneity of the illumination and thus the quality of the sweet spots shall be further improved, in particular if the structure of the illumination elements is very fine.
This object is solved in an inventive manner on the basis of a tracking method for a display with sweet spot unit and image matrix, whereby in several process steps starting with a real time detection of the spatial positions of observer eyes by a position finder, illumination elements, which are arranged in a regular pattern in an illumination matrix, are activated in the optical path in order to provide defined sweet spots to serve observer eyes.
According to this invention, the object is solved by a tracking method which includes an inverse ray tracing, where rays are traced starting at the observer eyes through the image matrix and the imaging means to the illumination matrix. This activates exactly those illumination elements of the illumination matrix which the observer can see when looking through the image matrix. In combination with the imaging means, but irrespective of the type of imaging means used, the observer eyes receive the directed illumination assigned to them in sweet spots.
After continuous detection of the spatial positions of the eyes of at least one observer with the help of a position finder, the detected position information is transmitted to a control unit which executes the inverse ray tracing. Depending on the accuracy of the position finder and/or other parameters, in particular the distance between the observer eyes and the display, geometry of the required sweet spot is defined in discrete steps in the control unit by determining reference points. Number and position of reference points for each observer eye can be chosen freely. In this invention, a square arrangement of reference points is preferred, i.e. the inverse ray tracing is executed for at least four points, which preferably describe a rectangle.
The number of reference points must be large enough for the sweet spots to be homogeneously illuminated at all times, but small enough to keep the required computing power and storage capacity as low as possible. A larger extent of the sweet spots will for example become necessary if the observer is situated relatively far away from the display so that the accuracy of the position detection is significantly reduced.
The control unit performs an inverse ray tracing starting at each reference point to pixels which are arranged in a grid on the image matrix and which are defined by at least one parameter. The calculations are preferably not performed for all pixels, but only for pixels which are located in one row so that they can be defined by only one parameter according to the given grid of the image matrix.
The inverse ray tracing is continued from the pixels through the imaging means to the illumination elements. The calculation produces data records with address information of this illumination element which is imaged by the corresponding imaging means to the respective reference point. In a subsequent process step, a pattern of illumination elements to be activated is generated based on the address information, and said pattern is imaged by the imaging means in the form of sweet spots defined above for each observer eye. The method according to this invention can be applied to both monoscopic and autostereoscopic displays for at least one observer.
While the inverse ray tracing for each pixel is preferably carried out for the central row of the image matrix in real time, the control unit looks up pre-calculated data records for finding address information of illumination elements stored in a look-up table for the further ray paths. The address information for a pattern of illumination elements which corresponds to the current observer position is found by the control unit by way of comparing the parameters of the data records, and it is used to generate a corresponding sweet spot, whereby the viewing angle α characterises the ray path from a reference point to the viewed pixel of the image matrix. The pre-calculated ray paths of the rays from each pixel in the grid of the image matrix to each illumination element of the illumination matrix are stored in data records in the look-up table.
Aberrations caused by the imaging means, such as field curvature, are preferably already taken into account in the data records. The same applies to known material and manufacturing tolerances and the temperature-specific behaviour of the optical elements used.
Using the viewing angle as a parameter for inverse ray tracing has the advantage that the number of calculations to be executed can be reduced, because a certain viewing angle may not only apply to one observer situated at a certain distance to the display, but for several observers situated at different distances. If all observers are provided the same stereo image, the address information preferably only contains two separate lists of illumination elements for the detected positions of all left and right eyes of the observers, respectively. The look-up table contains for a multitude of rays and viewing angles pre-calculated data records which are used to generate the sweet spots for the relevant pixels of the image matrix and all illumination elements of the illumination matrix. The entirety of these data records represents the transfer data of the look-up table.
One embodiment of this invention comprises an illumination matrix which consists of a shutter with discretely controllable sub-pixels combined with a directed backlight. Alternatively, the illumination matrix may comprise discretely controllable, light-emitting illumination elements such as LEDs or OLEDs, thus making redundant the backlight and maintaining the flat design of the display.
Further, this invention relates to a device for providing a control signal for tracking a sweet spot of a sweet spot unit in a display which comprises adequate control and storage means to implement the method according to the invention.
According to another embodiment of the invention, at least one additional optical component in the form of a scattering or diffraction element is used in the optical path, which is why an additional parameter exists for finding the address information and thus to improve the image quality and the homogeneity of the illumination. The control unit additionally detects and considers an angle θ (in angular ranges), which defines the optical properties of the scattering or diffraction means.
The angle θ is the scattering angle of a scattering means, which comprises at least one scattering element, or the diffraction angle of a diffraction means, which comprises at least one diffraction element.
Because a multitude of rays is required to generate a sweet spot, a multitude of angular ranges related to the angle α is used in the calculation. The control unit detects these angular ranges preferably depending on the grid size of the actually used illumination matrix. In order to keep the calculation simple, the angular range information is detected and considered independently of the position of the scattering or diffraction means in the optical path, but always at positions which are touched in the inverse ray tracing process. All illumination elements of the illumination matrix which are found in the course of the inverse ray tracing process are activated in order to generate a defined sweet spot.
Thanks to the fact that scattering or diffraction means are considered in the inverse ray tracing process according to the invention, additional illumination elements will be activated in a simple manner. This further reduces or even eliminates imaging defects such as dark stripes, cross talk and poor contrast.
The method according to this invention as used for tracking a sweet spot of a sweet spot unit makes it possible to minimise the volume of transfer data stored in a look-up table and the computing time required. In particular if individual observers are simultaneously provided with different information in a two-dimensional and/or three-dimensional mode, observer-specific image information can preferably be tracked in real time and at high quality if the observers change their positions in the viewing space.
BRIEF DESCRIPTION OF THE DRAWINGS
Now, the method according to this invention and a corresponding device will be described in detail. In the representations is
FIG. 1 a top view showing schematically a multi-user display with a sweet spot unit, an image matrix 4 and an observer eye 6 in a sweet spot 5 ,
FIG. 2 a top view showing rays of light which run from reference points P 1 to P 4 of a sweet spot to pixels D p and D r of the image matrix 4 with corresponding viewing angles α,
FIG. 3 a showing a list 7 of illumination elements which defines a pattern M of illumination elements LE,
FIG. 3 b showing a detail of the illumination matrix 1 with activated and not activated illumination elements LE,
FIG. 4 a top view showing a ray of light RT i which is followed in the inverse ray tracing process, said ray being scattered through a scattering means SF in an angular range of ±θ, and scattered ray portions RT i0 to RT i3 running towards the illumination elements LE, and
FIG. 5 a flow chart showing the inverse ray tracing routine in a display device.
DETAILED DESCRIPTION OF THE INVENTION
The description preferably refers to an autostereoscopic display.
Now, the method according to this invention for tracking a sweet spot 5 of a sweet spot unit if one or multiple observers change their positions in the viewing space, and a corresponding device, will be described in more detail in conjunction with an autostereoscopic display and with reference to FIGS. 1 to 5 . The method is based on the idea that for each observer position only those illumination elements LE are activated in order to generate a sweet spot which provide the stereo image to be displayed with ideal brightness and homogeneity and which maintain a high image quality. The object of this invention is realised with the help of an inverse ray tracing method and a corresponding device.
Referring to FIG. 1 , the autostereoscopic display includes the following main components: a sweet spot unit comprising the illumination matrix 1 with illumination elements LE 0n to LE qk and imaging means comprising a lenticular 2 and a Fresnel lens 3 . A transparent image matrix 4 with pixels D o to D q which is permeated by the unmodulated light of the sweet spot unit is used to render the stereo image. For the sake of simplicity the Figures only show one observer eye 6 and one sweet spot 5 which is defined by reference points P 0 to P n .
Demonstrating the inverse ray tracing process, FIG. 2 shows assumed ray paths running from the reference points P 1 to P 4 of the sweet spot to two randomly selected pixels D r and D p of the image matrix 4 and the corresponding four viewing angles α r1 to α r4 and α p1 to α p4 , respectively.
FIG. 3 a shows a list 7 of illumination elements which comprises all address information of all illumination elements LE of the illumination matrix 1 found by the control unit, said list of illumination elements defining a pattern M. The illumination elements LE which generate the defined sweet spot 5 (see FIG. 3 b ) will be activated in accordance with said pattern M.
FIG. 4 shows the path of a calculated ray RT i traced from a randomly selected reference point and its scattering through an exemplary scatter foil SF with a defined scattering angle θ. It is shown how additional illumination elements LE can be activated when an additional optical component having an angular range of ±θ and ±θ/2, based on the scattering angle θ at the position of a scattering or diffraction means SF. The angular range ±θ is here only detected in the horizontal direction. Generally, this process may additionally be performed in vertical direction.
FIG. 5 is a flow chart which shows the major process steps of the inverse ray tracing routine.
The illumination matrix 1 is a major element of the sweet spot unit of a multi-user display. It continuously provides the observer with an ideally and homogeneously illuminated stereo image through a sweet spot 5 , also if the observer moves. As described in the main patent application, position, number and extent of the sweet spots 5 to be generated can be controlled by a control unit and realised with the help of an illumination matrix 1 , which consists of a multitude of illumination elements LE 0n to LE qk which can be activated discretely, as shown in FIG. 1 . In the described embodiment, the illumination elements LE are monochrome illumination elements of an LCD, which are illuminated by a backlight (not shown).
However, they may also be LEDs, OLEDs or similar point- or line-shaped illumination elements which are arranged in a regular pattern and which can be activated discretely.
The imaging means is a multi-part component which consists of a lenticular 2 , that represents the optical imaging system, and a Fresnel lens 3 which serves as a field lens which images the sweet spot 5 on to an observer eye 6 . Alternatively, the imaging means may only be a lenticular 2 . If necessary, additional optical means may be integrated into the imaging means in order to enhance the imaging conditions. It is possible to complement the lenticular 2 composed of vertically arranged lenticules with at least one further lenticular composed of horizontally arranged lenticules. Further combinations of lenticulars are also possible. Instead of the lenticular 2 , a lens array composed of lens elements arranged in a matrix or an optical imaging system composed of prismatic elements may be used.
In a further embodiment, the imaging means may additionally comprise a corrective array for field curvature correction. Depending on the type of image matrix 4 used, an additional retarder foil may be disposed in the optical imaging path in order to modify the polarisation of the light. A certain number of illumination elements LE are always assigned to each imaging element.
Referring to the top view in FIG. 1 , an observer eye 6 is situated in a viewing space in front of the display, more precisely in an extended sweet spot 5 in a given plane. Initially, the sweet spot 5 does not exist in reality, but is pre-defined taking into consideration system parameters and viewing conditions. The extent of the sweet spot is described by reference points P 1 to P n . The reference points P 1 to P n may also be arranged in any pattern, including three-dimensional patterns. The parameter n should be at least four, so to define a rectangle for inverse ray tracing in order to be able to realise distinct sweet spots 5 . In this embodiment, n is 12. The depth of the sweet spot 5 may be lower or greater than shown here, depending on the accuracy of the position finder used and/or the position of the observer eye 6 with respect to the display. The sweet spot extent can be the smaller the more accurate the position finder works. Point P 0 denotes the eye position as detected by the position finder. If there is more than one observer, the position of all eyes 6 in the viewing space will be detected dynamically, and the corresponding position information will be provided to the control unit for inverse ray tracing.
After continuous real-time detection of the spatial position of an observer eye 6 in point P 0 , an imaginary sweet spot 5 is defined around the eye with the help of discrete reference points P 1 to P n . Ray paths RT 1 to RT n from each of the reference points P 1 to P n to pixels D 0 to D q in a selected row of the image matrix 4 are calculated in the control unit (see FIG. 1 ). The image matrix 4 is divided into a grid with constant pitch which forms the basis for the pixel calculations. The pitch of the grid may or may not be identical to the pitch of the image matrix 4 . However, it is also possible to use a grid which consists of several regions with different pitches. However, in the context of inverse ray tracing it is advantageous to use a larger pitch than that of the image matrix, because this reduces significantly the computing power required.
The pixels D 0 to D q are identified by the x coordinate within the row in which they are located. In practice, the central row of the image matrix is used, because observers prefer to view towards the centre of the image display. Another parameter required in the calculation is the viewing angle α under which the rays from the reference points P 1 to P n hit the pixels D 0 to D q of the grid. It has been found empirically that approximately 4,000 viewing angles α should be used to be able to achieve a sensible calculation result. If the number of viewing angles was considerably fewer than 4,000, the tracking precision would be adversely affected.
In the case of a two-dimensional imaging means, a pixel D is not only defined by its x coordinate, but by its x and y coordinates.
In the described embodiment in FIG. 1 , the illumination elements LE 0n to LE qk are monochrome illumination elements of a shutter which are illuminated by a backlight (not shown). The observer eye 6 is situated in the reference point P 0 . Rays of light running from the outer reference points P k and P n to the outer pixels D 0 and D q as calculated by the inverse ray tracing method are shown in the Figure. A ray of light running from the reference point P 1 to the pixel D p is shown together with the viewing angle α p1 under which the ray hits a pixel of the image matrix 4 .
The ray path from the pixel D p through the imaging element ends in the illumination element LE p1 of the illumination matrix 1 , said element being preferably located in the central row of the image matrix 4 . This calculation is carried out for all pixels D 0 to D q and for a large number of viewing angles α. This ensures that all illumination elements LE 0n to LE qk which must be activated in order to achieve a homogeneous illumination of the sweet spot 5 defined by the reference points P 1 to P n are hit. The illumination elements LE 0n to LE qk hit by the rays of light will be activated together with the corresponding columns.
If too few illumination elements LE 0n to LE qk are activated, the sweet spot 5 and the switched on image will be insufficiently illuminated. On the contrary, if too many illumination elements LE 0n to LE qk are activated, the sweet spot 5 additionally illuminates the other eye, thus leading to cross talk and a reduction of the stereo image contrast.
Another variation of a defined sweet spot is shown in FIG. 2 . It can be seen how in the course of the inverse ray tracing process the rays of light run from the four reference points P 1 to P 4 to two pixels D r and D p , thus having different viewing angles α r1 to α r4 and α p1 to α p4 , respectively. This sweet spot configuration is preferably used if an observer is situated very close to the position finder, so that the position of the observer can be defined by very few reference points with great accuracy.
Real-time inverse ray tracing from the reference points P of a defined sweet spot 5 to corresponding pixels D of a grid of the image matrix 4 produces as a result the input data for retrieving pre-calculated data records stored in a look-up table (LUT).
The look-up table contains pre-calculated data records, which represent the results of calculations of a large number of ray paths which have all been carried out according to the same algorithm, and the real-time calculation of which would take too much time. This is why all ray paths from each pixel D in the grid of the image matrix 4 through the imaging means to the two-dimensional coordinates of the illumination elements LE of the illumination matrix 1 were pre-calculated and stored in data records in the look-up table LUT.
However, it is also possible to calculate the ray paths up to the lenticular 2 in real time. This reduces the number of data records and thus saves storage capacity.
A comparison of the parameters of the data records calculated in real time and those pre-calculated and stored in the control unit produces address information of the illumination element LE which is imaged by the lenticular 2 and Fresnel lens 3 to the corresponding reference point P. An illumination element LE may be hit several times by the imaginary rays of light, as can be seen in the list 7 of illumination elements shown in FIG. 3 a . The number in the list indicates how often an illumination element LE was hit during inverse ray tracing starting at the reference points P. However, the number of hits is irrelevant when it comes to activating the illumination elements LE. Generally, all illumination elements LE which have been hit at least once by a ray of light RT will be activated. Based on the address information, the control unit generates a pattern M of all illumination elements LE which activate the corresponding columns of the illumination matrix 1 (see FIG. 3 b ). Now, this pattern is used to realise the sweet spot 5 for the observer eye 6 exactly at the defined position.
If there are multiple observers in front of the display, a sequence of patterns M of illumination elements LE to be activated is determined that corresponds with the actual number of observer eyes. For example, first all left eyes of the observers can be provided with the required stereo information using the inverse ray tracing method, then all right eyes, if all observers want to see the same content.
If according to the described inverse ray tracing method several illumination elements LE are not activated, the stereo image is perceived from the position of the sweet spot 5 with the above-mentioned disadvantages. For example, the margins of the individual lenticules may be discerned as dark stripes in the image, and the illumination of the image matrix 4 may be inhomogeneous. It has proven to be advantageous to additionally consider the scattering or diffraction of light in the inverse ray tracing process.
According to another embodiment of this invention, an angle θ is introduced which may be a scattering angle or a diffraction angle. It is detected and considered in the course of the inverse ray tracing process in defined angular ranges. For the sake of simplicity, the invention will be described below with the help of a scattering means. However, a diffraction means may be used analogously in other applications. The imaging means is preferably assigned to one scattering means with at least one scattering element in the optical path. The scattering element may be a scatter foil SF with a defined scattering angle. It may be disposed in front of or behind the Fresnel lens 3 or at another position in the optical path. If several scatter foils SF are used, each of these foils may have a different scattering angle, so that additional parameters in the angular ranges may be detected and considered to find address information, as shown in FIG. 4 . The same applies analogously to diffraction means and diffraction angles.
The invention also covers the possibility that the angular range may be detected and considered in both horizontal and vertical direction so to find additional address information. Referring to the embodiment shown in FIG. 4 , it is demonstrated schematically for one traced ray of light RT i how an angular range ±θ is defined based on the known scattering angle θ of a scatter foil SF. The selected ray of light RT i comes from a random reference point P and has passed through the image matrix 4 in a pixel D. It is scattered by the scatter foil SF so that a number of rays of light RT i0 to RT i3 (indicated by arrows) run to illumination elements LE i−2 to LE i+2 of the illumination matrix 1 . If the angular range ±θ is used for inverse ray tracing, every second illumination element will be activated. If the angular ranges are divided by 2 again (θ/2, as shown in FIG. 3 ), the illumination elements LE i−1 and LE i+1 will additionally be hit by rays in the course of the inverse ray tracing process. The number of illumination elements LE to be activated, which contribute to the homogeneous illumination of the defined sweet spot 5 , can thus be found more precisely and the risk of non-activation of illumination elements LE is further minimised. In reality, the number of rays of light to be additionally activated is much greater.
The angular range to be used in particular cases also depends on the grid size of the illumination matrix 1 used.
The finer the sizing of the illumination matrix 1 , the finer must the angular range used for inverse ray tracing be defined, based on the actual scattering or diffraction angle. It must be noted, however, that the finer the angular range the more address information is found and the more computing time is required. This is why it is important when employing the inverse ray tracing method to put only reasonable efforts into means and computing power while still achieving a good imaging quality and homogeneous illumination of the defined sweet spots 5 .
All found values of many angular ranges will be used by the control unit to detect and to consider address information. The address information includes in addition to the x coordinate a viewing angle α and an angle θ or θ/2 corresponding to the scattering angle or diffraction angle. The additionally found address information increases the accuracy of the minimum number of illumination elements LE to be activated that generate the sweet spot 5 .
Referring to FIG. 5 , a flow chart illustrates the inverse ray tracing process from the detection of the position of an observer eye 6 by a position finder to the definition of a pattern M of illumination elements LE to be activated in order to generate the defined sweet spot 5 .
This invention also relates to a device, more specifically a processor which comprises several functional units like control means and storage means, as defined in the independent device claim, for the implementation of the inverse ray tracing method described above.
The inventive method for tracking a sweet spot of a sweet spot unit preferably provides a display with the possibility to define an optimum pattern of illumination elements at minimum data volume to generate in an observer plane a sweet spot in which the observer sees specific information provided by an always homogeneously illuminated image matrix. Because aberrations are already considered in the inverse ray tracing method, the display preferably only exhibits very little optical errors. Using a look-up table boasts the advantage that the individual illumination elements required to generate the sweet spot do not have to be re-calculated repeatedly.
Consequently, the sweet spot and the corresponding stereo image can be tracked quickly and precisely in real time according to the movement of an observer eye, and the tracking range for an observer can be increased at the same time.
List Of Reference Numerals
1 —illumination matrix
2 —lenticular
3 —Fresnel lens
4 —image matrix
5 —sweet spot
6 —observer eye
7 —list of illumination elements
LE—illumination element
D—pixel
M—pattern
P—reference point
RT—ray of light
SF—scatter foil
α—viewing angle
θ—angle (scattering or diffraction angle) | The invention relates to a method and device for tracking the sweet spots of a sweets spot unit for a transmissive electronic display. The aim of the invention is to improve the reproduction quality and the uniformity of illumination in displays of this type. The display contains a sweet spot unit consisting of an illumination matrix ( 1 ) and reproduction elements, in addition to an image matrix ( 4 ). Once the position of at least one observer's eye ( 6 ) has been determined by a control unit using inverse ray tracing, address data for activating illumination elements (LE) of the illumination matrix ( 1 ) is provided from the position data in order to prepare the defined sweet spots ( 5 ) for said observer's eye ( 6 ). To improve the reproduction quality, an additional optical component is used in ray path for the inverse ray tracing process. In addition to the viewing angle (α) of the observer, the control unit detects and takes into consideration a defined angle (θ) of a scattering or diffractive element in a predetermined angular range. The permits additional address data to be activated for the illumination elements (LE) and the defined sweet spot ( 5 ) can be illuminated in a uniform manner. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to an alloy for use in building up industrial components subjected to service conditions requiring good impact toughness, resistance to tempering, and resistance to temper embrittlement. One such application of particular interest is for use in building up and reconditioning steel mill caster rolls.
Steel mill caster rolls typically have a forged or cast core substrate, a build-up layer (also referred to as simply a build up), and an overlayer of stainless steel overlay. It is critical that the build up layer have high yield strength so that the caster roll has sufficient compressive strength that it does not deform in service. It is also critical that the build up layer have high impact toughness so that cracks which tend to form in the overlayer do not propagate into and through the build up layer, that is, to help ensure that surface cracks in the overlay remain in the overlay. Two alloys which are commonly used as build up are as follows:
______________________________________ Alloy 1 Alloy 2______________________________________C 0.13 0.08Mn 1.0 1.0Si 0.5 0.5Cr 2.0 1.5Ni -- 1.0Mo 0.5 0.4v -- 0.15Fe Bal. Bal. (all % by weight)______________________________________
These prior alloys are susceptible to temper embrittlement, have low toughness, and are sensitive to cooling rate. Temper embrittlement, in particular, is a loss in toughness due to reheating of a metal deposit, corresponding to reduced Charpy V notch values, and is primarily attributable to carbide precipitation and increase in hardness. As such, these prior alloys can only be deposited employing a narrow cooling rate range in order to achieve the required properties, as cooling rate affects carbide precipitation. It is therefore necessary to interrupt deposition as the welding deposition interpass temperature (IPT) gets sufficiently high as to result in a cooling rate which is sufficiently low to promote carbide precipitation. Having to repeatedly interrupt the deposition of build up significantly reduces productivity. The susceptibility of these alloys to temper embrittlement and sensitivity to cooling rate also has a tendency to reduce the quality and consistency in the build up.
SUMMARY OF THE INVENTION
It is an object of the invention, therefore, to provide an alloy for building up industrial components subjected to manufacturing and service conditions requiring high yield strength, good impact toughness, resistance to tempering, temper embrittlement, and high-temperature abrasion; to provide an alloy for use in building up and reconditioning steel mill caster rolls; to provide such an alloy which has reduced susceptibility to temper embrittlement and reduced sensitivity to cooling rate and interpass temperature; to provide such an alloy which has enhanced toughness; to provide such an alloy which can be readily deposited using easily manufactured wire.
Briefly, therefore, the invention is directed to a low alloy steel for use in building up industrial components. In one aspect the alloy is in the form of a build up layer on an industrial component. In another aspect the alloy is in the form of a wire for use in depositing a build up layer by welding. The alloy steel has less than about 0.1% C by weight, between about 1.5% and about 5.0% Ni by weight, and between about 0.5% and about 3.0% Mo by weight. Vanadium and Cr are excluded from the low alloy steel sufficiently to avoid any significant precipitation of V carbide and Cr carbide upon deposition of the low alloy steel by welding onto an industrial component.
Other objects and features of the invention will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a graph comparing the temper response of the alloy of the invention to a prior art alloy.
FIG. 2 is a micrograph of the alloy of the invention.
FIGS. 3 and 4 are micrographs of prior art alloys.
DETAILED DESCRIPTION OF THE INVENTION
By incorporation of its stated components in the combinations described in detail below, the present invention achieves reduced sensitivity to cooling rate and interpass temperature, while achieving yield strength, compressive strength, and impact toughness critical to, for example, caster rolls. Interpass temperature corresponds to the temperature of a substrate onto which a weld deposit is applied. The substrate may consist of substrate as it is normally understood, such as a core of a caster roll, or to material deposited in an immediately preceding welding pass. An interpass temperature of 325° F. results in a faster cooling rate for the weld deposit material than, e.g., an interpass temperature of 500° F., because the substrate onto which material is deposited is cooler. As a general proposition with alloys containing carbide-forming elements, a faster cooling rate resulting from a lower interpass temperature is required to maintain carbide-forming elements in solid solution. If carbide-forming elements are not maintained in solution but are allowed to precipitate as carbides, there can be deleterious effects as carbides can serve as crack initiation sites. A faster cooling rate resulting from a lower interpass temperature addresses the carbide formation problem, but introduces its own problem, namely, reduced productivity as time must be allowed for the substrate to cool between passes. The alloys of the invention, however, are less sensitive to cooling rate, such that they can be deposited with less attention to interpass temperature, and thus with fewer interruptions for cooling, and thus with greater productivity.
The alloy of the invention contains a maximum C content of about 0.1%. The C content is preferably in the range of about 0.001 to about 0.06%. All percentages noted in this specification are by weight, and refer to elemental compositions, although such elements may be in a combined form in the alloy. Carbon increases the maximum attainable hardness, but C content is maintained below the above upper limits to avoid the formation of carbides, which can serve as initiation sites for cracking. Carbon content is also kept below these upper limits to maintain acceptable toughness. By maintaining C content in this range, required strength and toughness are achieved in a broader welding parameter range, such that interruptions associated with IPT sensitivity are reduced, and productivity is increased. Stated another way, problems associated with increased hardenability, in particular a narrow welding parameter window in which required strength and toughness are attainable, are reduced.
The Mn content of the alloy is maintained in the range of about 0.5% to about 3.0%, preferably in the range of about 0.5% to about 2.0%. Manganese has a solid solution strengthening effect in metals of the composition of the invention. Manganese significantly below the 0.5% specified does not provide the desired strengthening effect while Mn significantly above the specified upper limit tends to promote the formation of mixed microstructures of bainite and martensite, especially in the presence of up to about 1% Si.
The alloys of the invention contain from about 1.5% to about 5.0% Ni, preferably from about 1.5% to about 3.0%, to provide enhanced impact toughness. While Ni values below about 1.5% do not provide adequate toughness, Ni values significantly above the upper limits are avoided because there is no appreciable improvement in impact toughness in the context of the overall composition of the invention.
Molybdenum is incorporated into the alloys in the range of from about 0.5% to about 3.0%, preferably from about 0.5% to about 2.0%, for its solid solution strengthening effect. At the ultra low C levels of the invention, Mo advantageously promotes the formation of bainitic microstructures over a wide range of cooling rates. This is especially important in the context of the present invention, because it increases the range of welding parameters under which toughness critical to the efficiency of the deposit can be achieved.
Titanium is incorporated into the alloys of the invention in amounts up to about 0.05%, preferably within the range of about 0.01% to about 0.04%. The function of the Ti is to getter oxygen from solid solution, since oxygen in solid solution negatively affects toughness. Titanium in amounts above about 0.5% are avoided because of adverse effects on microstructure and toughness.
Vanadium is known to increase hardenability and provide solid solution strengthening. However, intentional additions of V are specifically avoided in this invention because V has a tendency to render the alloys sensitive to cooling rate and susceptible to temper embrittlement. Vanadium is a strong carbide former, and carbides in deposited weld metal can block dislocation slip bands, reducing ductility. Carbides can also crack or separate from a metallic matrix under stress, thus generating microcracks which can act as crack growth sites and adversely affect toughness. Repeated heating and cooling of V-containing steels can lead to the formation of coarse carbides drastically lowering weld metal toughness. By eliminating more than incidental V, it has been discovered that the desired mechanical properties can be achieved while using a much broader range of welding parameters. This is critical in the specific context of surfacing of steel mill rolls where high interpass temperatures are encountered unless the surfacing process is repeatedly interrupted. Avoidance of such repeated interruptions is advantageously facilitated by the elimination of V, because such elimination reduces the sensitivity of the alloys to cooling rates, and consequently promotes tolerance for high IPTs. Accordingly, V is excluded from the alloys of the invention sufficiently to avoid any significant precipitation of V carbides, preferably any precipitation of V carbides at all. Preferably, the alloys contain essentially no V; more preferably, they contain no V.
Chromium has been incorporated into high alloy steels to provide corrosion resistance and high temperature strength, and has been incorporated into low alloy steels to increase hardenability and solid solution strengthening. Chromium, like V, is a strong carbide former, and carbides in deposited weld metal can block dislocation slip bands, reducing ductility. Carbides can also crack or separate from a metallic matrix under stress, thus generating microcracks which can act as crack growth sites and adversely affect toughness. Repeated heating and cooling of Cr-containing alloys can lead to the formation of coarse carbides drastically lowering weld metal toughness. Intentional additions of Cr are specifically avoided in this invention because Cr has a tendency to render the alloys sensitive to cooling rate and susceptible to temper embrittlement. By eliminating more than incidental Cr, it has been discovered that the desired mechanical properties can be achieved while employing a much broader range of welding parameters. This is critical because in the specific context of surfacing of steel mill rolls high interpass temperatures are encountered unless the surfacing process is repeatedly interrupted. Avoidance of such repeated interruptions is advantageously facilitated by the elimination of Cr, because such elimination reduces the sensitivity of the alloys to cooling rates, and consequently promotes tolerance for high IPTs. Accordingly, Cr is excluded from the alloys of the invention sufficiently to avoid any significant precipitation of Cr carbides, preferably any precipitation of Cr carbides at all. Preferably, the alloys contain essentially no Cr; more preferably, they contain no Cr.
Other elements which are carbide formers in the context of the alloys of the overall composition of the alloys of the invention are also preferably avoided. Accordingly, carbide forming elements are excluded from the alloys of the invention sufficiently to avoid any significant precipitation of carbides, preferably any precipitation of carbides at all. Preferably, the alloys contain essentially no carbide formers; more preferably, they contain no carbide formers. Among such carbide formers, Nb, W, and B are excluded from the alloys of the invention sufficiently to avoid any significant precipitation of Nb, W, and B carbides, preferably any precipitation of such carbides at all. Preferably, the alloys contain essentially no Nb, W, or B; more preferably, they contain no Nb, W, or B.
The microstructure of the alloy of the invention consists of entirely carbide-free bainitic ferrite. The alloy contains essentially no polygonal ferrite, essentially no martensite, and essentially no austenite.
The alloy of the invention contains the following constituents:
______________________________________C ≦0.1Mn 0.5-3.0Si ≦1.0Ni 1.5-5.0Mo 0.5-3.0Ti ≦0.05Fe Bal. plus incidental trace elements. One preferred alloy contains:C 0.001-0.06Mn 0.5-2.0Si 0.1-0.4Ni 1.5-3.0Mo 0.5-2.0Ti 0.01-0.04Fe Bal. plus incidental trace elements. One particularly preferred alloy contains:C 0.04Mn 1.5Si 0.4Ni 2.5Mo 0.6Ti 0.03Fe Bal. plus incidental trace elements, including P (0.012%) and S (0.006%).______________________________________
In order to achieve alloys of the foregoing composition by submerged arc welding deposition, a wire is used which consists of an alloy powder mixture encased within a carbon steel sheath (e.g., AISE 1008), which alloy powder mixture and sheath combine to form the foregoing alloy.
The invention is further illustrated by the following Example.
EXAMPLE
Welds were made on 3/4 inch thick A36 steel plates with a 45° `V` groove by submerged arc welding using 1/8 inch diameter wire consisting of AISE 1008 sheath encasing alloy powder. The current was 450 amps; the voltage was 28 volts; the travel speed was 16 inches/minute; the heat input was 47 kJ/inch; and the flux was neutral basic. The welds were made according to standard procedure ANSI/AWS A5.17-89. The undiluted weld deposit composition and calculated wire compositions are presented in Tables I and II. The pre-heat and interpass temperatures used for each weld are provided in Table III. Charpy V notch and 0.5 inch round tensile specimens were extracted from the weld centerline according to ANSI/AWS B4.0 and tested in accordance with ASTM E8-95a and E21-92.
TABLE I______________________________________All Weld Deposit Compositions Alloy of the Comparative Comparative Invention Alloy-1 Alloy-2______________________________________C 0.04 0.15 0.09Mn 1.5 1.0 0.87Si 0.4 0.39 0.5Cr -- 0.6 0.88Ni 2.5 0.57 1.26Mo 0.6 0.2 0.41Ti 0.03 -- --V -- -- 0.15P 0.012 0.015 0.015S 0.006 0.004 0.004Fe Bal. Bal. Bal.______________________________________
TABLE II______________________________________Wire Compositions for Alloys in Table I Alloy of the Comparative Comparative Invention Alloy-1 Alloy-2______________________________________C 0.08 0.22 0.12Mn 1.4 0.79 0.55Si 0.44 0.46 0.61Cr -- 0.54 0.85Ni 2.8 0.48 1.3Mo 0.56 0.19 0.4Ti 0.2 -- --V -- -- 0.12Fe Bal. Bal. Bal.______________________________________
TABLE III__________________________________________________________________________Comparison of the mechanical properties of the weld metal deposited usingthealloy of the invention (New Alloy) to that of the current state of theart alloys.Experiment Preheat IPT PWHT UTS YS Average CVNNo: Alloy (° F.) (° F.) (° F.) (ksi) (ksi) E 1% RA % (ft-lb)__________________________________________________________________________1 New 200 325 6 hr @ 115.1 106.9 24.4 65.9 120 Alloy 11752 Alloy 200 325 6 hr @ 102.1 94.1 22.8 71.5 1221 11753 Alloy 200 325 6 hr @ 114 104 22 66 69.82 11754 New 200 550 6 hr @ 110.3 96.4 25.2 66.1 117 Alloy 11755 Alloy 200 550 6 hr @ 114 105 24 64 522 11756 New 300 700 As 112.7 94.9 25 42.7 110 Alloy Welded7 Alloy 300 700 As 111.9 96.7 16.6 44.8 702 Welded8 New 300 700 6 hr @ 121.56 101.9 22.6 57.8 81 Alloy 11009 Alloy 300 700 6 hr @ 113.4 98.2 22.8 59.8 69.21 110010 Alloy 300 700 6 hr @ 118.7 109.2 24 62.1 542 1100__________________________________________________________________________
TABLE IV__________________________________________________________________________Effect of furnace cooling on the CVN toughness of the alloy of theinvention(New Alloy) and Alloy-2; Average CVNExperiment No: Alloy Preheat (° F.) IPT (° F.) PWHT (° F.) (ft-lb)__________________________________________________________________________11 New Alloy 300 700 6 hr @ 1100 & 98 Furnace Cool12 Alloy - 2 300 700 6 hr @ 1100 & 55 Furnace Cool__________________________________________________________________________
In Table III, experiments 1, 2 and 3 show the results of tests carried out with a preheat of 200° F. and an interpass temperature of 325° F. with a subsequent postweld heat treatment (PWHT) at 1175° F. for 6 hrs. In a practical welding situation this would mean that the welding would have to be interrupted frequently to allow the interpass temperature to fall to below 325° F. in order to maintain a relatively fast cooling rate. Under these conditions (325° F.), Alloy-1 and the alloy of invention (New Alloy) behave similarly with relatively high yield strength (YS) and impact toughness (CVN). Alloy-2 exhibits relatively low impact toughness. However, low interpass temperatures result in low productivity due to the frequent interruptions required for the roll to cool down below the interpass temperature.
When the interpass temperature is raised to 550° F., resulting in an intermediate cooling rate and less frequent interruption of welding operation, experiments 4 and 5 show that the alloy of the invention has more than twice the impact toughness when compared to the present art Alloy-2.
When the interpass temperatures is further raised to 700° F., representing a slow cooling rate, experiments 6 and 7 show that in the as-welded condition, the alloy of the invention has about a 40% higher impact toughness compared to that of Alloy-2.
Experiments 8, 9 and 10 reveal the influence of welding using a relatively high interpass temperature of 700° F. followed by PWHT. The high interpass temperature indicates that welding can be conducted on rolls without interruption thus resulting in increased productivity. Although Alloys-1 and Alloy-2 as well as the alloy of the invention posses comparable yield strengths, the alloy of the invention retains higher impact toughness. The deterioration of the toughness of Alloy-1 and Alloy-2 is related to the fact that they contain higher levels of carbon and carbide formers such as chromium and vanadium. Carbide precipitation during PWHT results in a degradation of the impact toughness. Carbide precipitation also results in a loss of hardness at elevated temperatures as shown in FIG. 1. The alloy of the invention retains its hardness even after exposure to temperatures as high as 1200° F. when compared to Alloy 1 which suffers a rapid loss of hardness after exposure to temperatures above 900° F. Loss in hardness results in a loss of compressive strength, while compressive strength is a critical property for roll build-up materials. Since the alloy of the invention has a very low carbon content and does not contain any carbide formers, there is no deterioration of impact toughness with PWHT. A micrograph of the alloy of the invention in the PWHT condition is shown in FIG. 2. The microstructure is bainitic without any detectable carbide precipitation. In contrast, the microstructure of Alloy-1 contains some carbides and polygonal ferrite (FIG. 3) which is detrimental to toughness. FIGS. 3 and 4 show the microstructures in the PWHT condition of Alloys 1 and 2 respectively. There is significant carbide precipitation in these alloys due to the higher carbon and carbide formers (Cr, V) content. This is further demonstrated in Table IV where the alloy of the invention and Alloy-2 have been welded at an interpass temperature of 700° F. and have been then furnace cooled from the PWHT temperature of 1100° F. Such furnace cooling to room temperature requires a period of almost 24 hours, which would simulate potential temperature exposures in caster roll applications. This relatively slow cooling rate exacerbates any carbide precipitation problems. The alloy of the invention (experiment 11) retains impact toughness almost twice that of Alloy-2 (experiment 12).
In summary, the alloy of invention maintains high strength and toughness levels over a wide range of welding conditions. This wide range of welding conditions is in contrast to the high cooling rate conditions required with Alloy-1, which rates severely limit productivity. Alloy-2 does not meet the impact toughness requirements under any welding condition. Thus the alloy of invention can be deposited with the highest productivity (high preheat and interpass temperature). At the same time, it results in deposits that have higher yield strength and impact toughness when compared to the present art Alloys 1 and 2. This results in reconditioned rolls that have significantly better resistance to deformation as well as the ability to resist the propagation of any cracks that may have initiated in the overlay material.
As various changes could be made in the above embodiments without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense. | A low alloy steel for use in building up industrial components subjected to service conditions requiring good impact toughness, resistance to tempering, and resistance to temper embrittlement, for example, for use as a build up layer for steel mill caster rolls and a submerged arc welding wire for deposition thereof. The composition of low alloy steel has less than about 0.1% C by weight, between about 1.5% and about 5.0% Ni by weight, and between about 0.5% and about 3.0% Mo by weight. Vanadium, Cr, and other carbide-formers are excluded from the low alloy steel sufficiently to avoid any significant precipitation of carbides upon deposition of the low alloy steel by welding onto an industrial component. | 1 |
BACKGROUND OF THE INVENTION
1. Field of The Invention
This invention relates to well apparatuses and to anti-rotation devices for well apparatuses used in well operations, such as plugs, jars, float collars, float shoes, cementing stage tools, liner hangers, and clutch devices for packers; and in one embodiment to non-rotating plugs for well cementing operations.
2. Description of Related Art
Once a wellbore has been drilled, operations within the wellbore are facilitated by placing a string of tubular casing in the wellbore so that operations can be conducted in and through the casing rather than in an un-cased wellbore.
For a variety of reasons, cement is introduced into the annular space between the interior wall of the wellbore and the exterior surface of the casing: to form a protective barrier around the casing; to isolate multiple producing formations through which the wellbore extends; and to displace unwanted fluids or material in the annular space between the wellbore and the casing.
After a cased wellbore has been perforated so that production at a particular depth and from a particular formation is achieved, secondary cementing is often employed to force cement into the perforations to seal off the formation, wellbore, and casing. When it is desired to reduce the depth of a wellbore or to place cement at particular points in a wellbore, a technique called "plug back cementing" is employed.
Usually cement is introduced into the annular space between a wellbore and a string of casing by pumping the cement down through the casing, out through the opening at the end of the casing, and back up into the annular space. To prevent the cement from flowing back up into the casing, float shoes and float collars are used at or near the end of the casing. Float collars usually comprise restrictions or shoulders of cement within a tubular member which can be interposed between two casing joints a few joints above a float shoe at the end of the casing string. Either or both of the collar and shoe usually have a check valve which prevents the back flow of cement from the annular space back up into the casing.
A variety of plugs are typically used in cementing operations. These plugs are moved down into the casing by pumping cement or a fluid into the casing on top of the plugs. These plugs accomplish a variety of functions. They provide a divider or separation barrier between the cement on top of the plug and any fluid beneath the plug or between cement beneath the plug and a fluid on top of the plug. Plugs with wipers wipe off the interior surface of the casing as they pass through it. Plugs of sufficient bulk assist in preventing the back flow of cement beneath the plugs.
In a typical cementing operation a collar or shoe, or both, are placed on a casing string and casing is run into the wellbore to a desired level. A bottom pump down plug is then inserted into the casing and wet cement is pumped on top of the plug. The plug moves down the casing, pushing in front of it any fluid, such as drilling fluid or water, which may be present in the casing. The plug moves down until it encounters the float collar. Increased pumping pressure and the weight of the cement above the plug break a diaphragm disposed across a channel that extends through the plug. This permits the cement to flow through the float collar, the weight of the cement forcing open any check valves in the collar or shoe. The cement then flows out from the bottom of the casing, into the wellbore, and up into the annular space between the wellbore and the casing.
To raise the cement to a desired level in the annular space, a top pump down plug is inserted into the casing. Fluid is pumped onto the top pump down plug moving it into contact with the cement. Further fluid pumping pushes the top pump down plug and the cement down into the casing, forcing cement out of the bottom of the casing and further up in the annular space until a desired level of cement is reached. The top plug can be pumped down to contact the bottom plug. The cement then sets and various operations are carried out in the wellbore.
When the well operations have been completed, the plugs, collar and shoe may be drilled out. All of these items are made from drillable material such as plastic, rubber, wood, or drillable metal. The cement in the float collar is also drillable.
Often a rotating drill bit will contact a plug and cause the plug to rotate and then slip on the surface with which it is contact, e.g. the top of a bottom plug or a layer of cement. This slipping is inefficient and wastes time and energy. A variety of prior art devices have addressed this problem. The attempted solutions typically involve the use of some sort of protrusions, projections or teeth on plug ends to prevent rotation or the use of a plate with teeth on both sides that is placed between a plug and a surface over which a plug could potentially slip.
A variety of problems have been encountered with these prior art efforts. Often the teeth on the various devices contact each other and it is then the teeth alone that are forced to bear whatever load is imposed on the plug or plate. These loads can be enormous, crushing or distorting the teeth so that they do not function properly. Other prior art plugs have teeth which are configured and disposed so that the leading edges of the teeth meet and cross, not permitting further engagement of the lateral portions of the teeth. In other plugs the profile, number, and spacing of the teeth is such that any object or debris between the plugs prevents interengagement of the teeth on two adjacent plugs; i.e., the plugs are prevented from accomplishing the desired non-rotating function. With prior art devices in which the teeth are relatively short, slight separation caused for example by a bouncing drill bit off of two tools, e.g. plugs, with such teeth can cause disengagement, relative spinning movement, or ratcheting between the teeth, i.e., the non-rotation function is not accomplished. Previously used protrusions for piercing or gripping rubber may not have sufficient gripping engagement to prevent rotation.
There has long been a need for an effective and efficient structure for preventing the relative rotation of well plugs and other devices and tools during well operations, including, but not limited to, the drill out of plugs and cement. There has long been a need for a structure that keeps teeth or protrusions from preventing the relative rotation of devices. There has long been a need for a structure that prevents teeth or protrusions from bearing large loads which can injure the teeth or protrusions. There has long been a need for a structure which prevents debris or foreign objects from inhibiting the interengagement of such teeth or protrusions. There has long been need for an easily drillable plug.
In accordance with 37 C.F.R. §1.56, the following are disclosed:
U.S. Pat. No. 4,190,111 discloses a plate with tooth-like protrusions on each side which can be placed between objects in a well such as a plug and a float shoe or collar to prevent their relative rotation.
U.S. Pat. No. 4,836,279 discloses a plug which has downwardly facing elongated projections (rather than teeth and relatively much longer than teeth) and another plug with a plurality of longitudinal recesses (rather than teeth) corresponding to the elongated projections for preventing the relative rotation of the plugs.
"Halliburton's Non Rotating Cementing Plugs," Halliburton Services Sales Technical Data discloses cementing plugs with locking teeth (rather than elongated projections and corresponding recesses) on both the top and bottom plug and on a float collar for preventing plug rotation during drill out.
U.S. Pat. No. 4,711,300 discloses cementing plugs and collars with locking interfaces for preventing relative rotation.
U.S. Pat. No. 3,550,683 discloses a float shoe with slots for receiving a plug with corresponding protuberances on the plug to prevent plug rotation during drill out.
The following are of general interest and provide general information related to plugs and well cementing operations: U.S. Pat. Nos. 3,842,905; 3,006,415; and 4,706,747; Oil Well Cementing Practices in The United States, American Petroleum Institute, page 112, 1959; Halliburton Services Sales and Service Catalog, Volume 4, 1986-87 Composite Catalog pages 2440-2451; Chapter 10, primary Placement Techniques; Weatherford General Services and Products Catalog 1988-89, 1987, pages 4132-4139.
SUMMARY OF THE INVENTION
The present invention is directed to a structure which prevents the relative rotation of devices used in wellbore operations, such as plugs, float collars, float shoes, jars, and clutch devices for packers.
In one embodiment of the present invention an apparatus is provided which has a generally cylindrical body member with an inner recess in which a plurality of teeth or protrusions are disposed and from which a portion of the teeth or protrusions extend. A portion of the body member, such as a continuous or discontinuous inner or outer portion of the body member, is configured and disposed as a load member so that when two such apparatuses are moved together the load member portions of their body members come into contact thereby transferring a load on the apparatuses through this load member rather than on the protrusions. The teeth or protrusions are configured and disposed so that they extend sufficiently to interengage with the teeth or protrusions on an adjacent member; but they do not extend to such a length that they prevent the load members of two adjacent apparatuses from contacting to take a load off of the teeth or protrusions. In certain preferred embodiments these load members are continuous rings disposed either around the body member's outer periphery or around a channel opening central to the body. However, these load members need not be rings and they need not be continuous. Such an apparatus can be conveniently placed in, formed of, disposed in or on, or threadedly connected to a variety of devices such as plugs, float collars, and stage cementing tools to prevent the relative rotation of the devices and to prevent large loads from crushing or otherwise damaging the teeth or protrusions.
In one embodiment the teeth or protrusions are configured, profiled, and disposed so that their cross-section is constant from the outer edge of the apparatus to a more central point thus providing a tooth or protrusion with strength along its entire length and for easy interengagement with the teeth or protrusions of another similar device. In one embodiment the teeth or protrusions are profiled, configured, and disposed so that space is provided between them for foreign objects or debris which might otherwise prevent or impede proper interengagement of the teeth or protrusions. In one embodiment the outer edges of the teeth or protrusions are bevelled inwardly to facilitate interengagement between apparatuses. In one embodiment a plug is provided with all of these features. In one embodiment a float collar is provided with some or all of these features. In one embodiment a frangible diaphragm is disposed in a groove in the apparatus which, when broken, permits fluid flow through a longitudinal channel through the apparatus. In one embodiment a bottom pump down plug with all of these features is provided. Protrusions or projections (one or more) may be provided on the device for protruding into a material like cement or plastic in which the device is disposed or embedded to prevent movement or rotation of the device with respect to the material. Recesses, scoops, pockets, indentations or grooves (one or more) can provide a similar function when disposed so that a portion of the material is set within the recess, etc. to prevent relative movement.
The present invention, therefore, recognizes, addresses, meets, and satisfies the previously-described long-felt needs.
It is therefore an object of the present invention to provide a unique, new, useful, efficient and nonobvious device for preventing the relative rotation of well apparatuses.
Another object of the present invention is the provision of a device which can be formed of or connected to a variety of well tools and apparatuses, such as, but not limited to, plugs, float collars, jars, stage cementing tools, liner hangers and clutch devices for packers to prevent their relative rotation, particularly during drill out.
A further object of the present invention is the provision of such a device or such apparatuses in which teeth or protrusions do not bear some or any of the load which may be impressed on such a device.
An additional object of the present invention is the provision of such a device or such apparatus in which teeth or protrusions on the device are spaced so that debris or foreign objects may be contained between the teeth or protrusions without hindering the interengagement of the teeth or protrusions.
Yet another object of the present invention is the provision of such a device or apparatuses with such a device in which the teeth or protrusions are configured and profiled so that their cross-section is constant from an outer edge of the device to a more central point for strength and for easy interengagement with the teeth or protrusions of another device.
A specific object of the present invention is the provision of such a device or apparatuses with such a device in which an outer edge of the teeth or protrusions is bevelled inwardly to facilitate the interengagement of two such devices.
Another object of the present invention is the provision of a non-rotation device with one or more protrusions and or one or more pockets for inhibiting or preventing movement of the device with respect to a material (e.g. concrete, cement, or plastic) in which the device is disposed.
Specific objects of the present invention are the provision of plugs, float collars, jars, stage tools, liner hangers and clutch devices for packers with some or all of the above-described features.
To one of skill in this art who has the benefits of this invention's teachings and disclosures, other and further objects and advantages will be clear, as well as others inherent therein, from the following description of presently-preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. Although these descriptions are detailed to insure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to claim an invention no matter how others may later disguise it by variations in form or additions or further improvements.
DESCRIPTION OF THE DRAWINGS
So that the manner in which the above-recited features, advantages and objects of the invention, as well as others which will become clear, are attained and can be understood in detail, more particular description of the invention briefly summarized above may be had by reference to certain embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate preferred embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective equivalent embodiments.
FIG. 1 is a side view, half in cross-section, of a plug according to the present invention.
FIG. 2 is a side view, half in cross-section, of a plug according to the present invention.
FIG. 3A is a top view of a device according to the present invention. FIG. 3B is a side, view in cross-section of the device of FIG. 3A. FIG. 3C is a view along line C--C of FIG. 3A. FIG. 3D is a side view of a modified version of the device of FIG. 3A.
FIG. 4A is a top view of a device according to the present invention. 4B is a view along line B--B of FIG. 4A. FIG. 4C is a view along line C--C of FIG. 4A. FIG. 4D is a view along line D--D of FIG. 4A.
FIG. 5 is a side view partially in cross-section of a top plug, bottom plug, and float shoe according to the present invention.
FIG. 6a is a top view of an anti-rotation device according to the present invention. FIG. 6b is a side view in cross-section of the device FIG. 6a.
FIG. 7a is a top view of a device according to the present invention.
FIG. 7b is a side view in cross-section of the device of FIG. 7a.
FIG. 7c is a view along line E--E of FIG. 7a.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 a top plug 10 according to the present invention is shown which has a body 12 with a plurality of flexible wipers 14 formed integrally of and extending from the body 12. A top member 18 extends across the top of the body 12 and a bottom member 17 extends around the bottom of the body 12.
A non-rotation device 20 according to the present invention has a main member 21 with threads 26 for threadedly engaging a threaded opening 16 in the body 12 of the plug 10. An empty chamber 15 is in the center of the body 12. A plurality of teeth 22 extend from a recessed portion 23 of the main member 21 of the device 20. Herein and in the appended claims "protrusion" is meant to include a variety of shapes including bevelled, pointed, squared, rounded and non-pointed shapes whereas "teeth" is a narrower term indicating a pointed structure. A ring 30 having a face 31 extending from the main member 21 defines the periphery of the recessed portion 23 and partially extends into an opening 15 in the bottom member 17 of the plug 10. A shoulder 32 of the main member 21 abuts a face 13 of the body 12 of the plug 10. In another preferred embodiment the device 20 is disposed so that the face 31 is flush with a face 19 of the bottom member 17.
Referring now to FIG. 2, a bottom plug 40 according to the present invention has a body 42 with a plurality of wipers 44 formed integrally of and extending from the body 42. A top member 48 extends around the top of the body 42 and a bottom member 47 extends around the bottom of the body 42.
A non-rotation device 50 according to the present invention (like the previously described device 20) has a main member 51 with threads 56 for threadedly engaging a threaded opening 46 in the body 42 of the plug 40. A plurality of teeth 52 extend from a recessed portion 53 of the main member 51 of the device 50. A ring 60 extending from the main member 51 defines the periphery of the recessed portion 53 and partially extends into an opening 45 in the bottom member 47 of the pluq 40.
A groove 54, partially defined by a shoulder 58, in the top of the main member 51 of the device 50 is suitable for receiving and holding a portion of a diaphragm or other object for closing off a channel 64 which extends longitudinally through the device 50 and is in fluid communication with a channel 41 extending longitudinally through the plug 40. A shoulder 62 of the main member 51 abuts a face 43 of the body 42 of the plug 40.
Another non-rotation device 70 according to the present invention has main member 71 with threads 76 for threadedly engaging a threaded opening 49 in the body 42 of the plug 40. A plurality of teeth 72 extend from a recessed portion 73 of the main member 71 of the device 70. A ring 80 extending from the main member 71 defines the periphery of the recessed portion 73 and extends to the top of the top member 48 of the body 42 of the plug 40.
A groove 74, partially defined by a shoulder 78, in the bottom of the main member 71 is suitable for receiving and holding a portion of a diaphragm or other object for closing off a channel 84 which extends longitudinally through the device 70 and is in fluid communication with the channel 41 of the plug 40. A shoulder 82 of the main member 71 abuts a face 45 of the body 42 of the plug 40.
Referring now to FIGS. 3A, 3B, and 3C, a non-rotation device 100 has a main body 101 with a threaded periphery 106 for threaded engagement with a female-threaded opening in an apparatus such as a plug or other well apparatus or tool. Of course it is within the scope of this invention to provide a device without a threaded periphery and to connect, attach, adhere, or incorporate such a non-rotation device in an apparatus or tool by any appropriate and effective method and means.
A plurality of teeth 102 extend from a recess 103 defined by a floor 105 and a side wall 107 of a ring 110 which encircles the upper portion of the main body 101. The teeth 102 extend from the side wall 107 (the outer edge of the recess 103) inwardly to the inner edge of an opening 114 (see FIG. 3A) which extends longitudinally through the plug and through which fluid flow is permitted. A circular groove 104 is disposed in the bottom of the device 100 and is configured to receive and hold a portion of a frangible diaphragm which closes off the opening 114 to fluid flow until it is broken, e.g. by the force of cement. (The "upper portion" and "bottom" of the device 100 refer to its orientation as presented in FIG. 3B--of course it may be inverted as shown in FIG. 2, device 50). The side wall 107 as shown in FIG. 3B is perpendicular to the floor 105, but it is within the scope of this invention for the wall 107 to slope from the ring 110 to the floor 105; it could mirror the angle of the teeth.
It is preferred that the distance a (FIG. 3B) from the floor 105 to the top of the ring 110 be greater than the distance b from the top of the ring to the top of the teeth so that when two of the devices such as device 100 are disposed adjacent each other with their teeth interengaged, the two rings such as rings 110 meet, contact, and bear any load on the devices while the teeth are prevented from contacting the floor of the recess of the adjacent device. In this way the rings bear a load on the devices rather than the teeth and damage due to such loading on the teeth is eliminated. In one embodiment the distance a is 0.56 inches and the distance b is 0.531 inches.
As shown in FIG. 3A, it is preferred that the teeth 102 have a constant cross-section from the inner edge of the ring 110 to the outer edge of the opening 114; i.e., their dimensions are substantially constant from the outer edge of the recess to the inner edge of the opening. Such teeth are relatively stronger as they approach the opening 114 than would be teeth whose cross-section diminishes from the outer edge of the device towards its interior. The use of a ring such as the ring 110 serves to buttress the outer edge of the teeth, protecting them and strengthening the device. Also, in some prior art devices, teeth with a diminishing cross-section are shorter the nearer they are to a device's center. It is much easier for shorter teeth to either fail to engage or to ratchet across each other.
The device 100 as shown in FIG. 3A has six teeth. It is within the scope of this invention to provide a device with one or more teeth, but it is preferred that a number of teeth be provided and spaced apart so that the space between teeth at the inner edge of an opening (such as a space 111 between the teeth 102 of device 100) and the area between teeth (such as an area 113 between the teeth 102 of the device 100) can accommodate foreign objects and debris which, if it were present on the teeth of prior art devices would inhibit or prevent proper tooth interengagement. The size of a foreign object which can be accommodated in the area 113 is determined by the size of that area. If only one tooth is used, a larger object can be accommodated; but if, e.g., ten teeth were used, the size of such an object would be smaller. Objects from above encountering a pointed tip of a tooth will move and be diverted into one of the areas 113.
Since teeth (or other protrusions) according to the present invention are partially within the device, a minor disengagement of a bouncing drill bit or of adjacent apparatuses with such devices will not result in the disengagement of the teeth of the two devices. Teeth in prior art devices that simply extend from a top surface of the device are more easily disengaged.
Referring now to FIG. 3C, the tooth 102 has a cross-sectional profile that includes a perpendicular side, side 119; a slanted side, side 120; and a base, side 121. The angles between sides are: angle 116-40°; angle 118-90°; and angle 117-30°. This profile is advantageous because the torque of drill out will be transmitted through a right angle (118) and angle 116 will give support against tooth failure. There will be only a minimal force component (or none) trying to force the teeth up or down to disengage them. Although angles 116 and 117 are shown with a preferred extent, workable preferred ranges for these angles are: angle 116, 20 to 70 degrees; angle 117, 20 to 70 degrees; angle 118, 90 to 45 degrees.
As shown in FIG. 3B, the outer edge of the teeth 102 is bevelled inwardly, see bevel 112, to facilitate the interengagement of the teeth on adjacent devices. As shown in FIG. 3B the bevel 112 is 30° from normal, but any bevel which provides this facilitation may be used.
As shown in the modified version of the device 100 in FIG. 3D, a cut-out, scoop, indentation, or recessed area 115 is provided so that when the device 100 is emplaced within a material that sets up, e.g. concrete or which hardens, e.g. a thermosetting material or plastic, some of the material enters and sets within the recess to inhibit or prevent movement of the device 100 with respect to the material. Although one recess is shown, it is within the scope of this invention to use one or more recesses; it is also within the scope of this invention to position the recess or recesses as desired on the device. The recess may be configured as desired. The recess 115 is like a pocket in the body of the device 100, but it is within the scope of this invention to employ recesses of different shapes, including but not limited to an elongated recess or a groove partially or entirely encircling the device 100. A projection 109 extending from the device 100 is also used to inhibit or prevent movement of the device 100 with respect to materials as already described. One or more projections may be employed and it or they may be disposed as desired on the device 100 within the scope of this invention; also although the projection 109 is shown as finger-like, any desirable configuration may be used.
A non-rotation device 140 as shown in FIGS. 4A, 4B, and 4C is very similar in structure and operation to the device 100 previously described; but the device 140 has a plurality of teeth 142 with a slightly different cross-sectional profile. As shown in FIG. 4C, a tooth 142 with sides 159, 160, and 161, as viewed from the end, forms a triangle with angles of 50° (angle 156); 75° (angle 158); and 55° (angle 157). A tooth with this profile has strength for engagement and when torque is applied. Although angles 156, 157, and 158 are shown with a preferred extent, workable preferred ranges for these angles are as follows; angle 156, 20 to 70 degrees; angle 157, 20 to 70 degrees; and angle 158, 90 to 45 degrees.
The non-rotation device 140 has a main body 141 with a threaded periphery 146 for threaded engagement with a female-threaded opening in another apparatus. A plurality of teeth 142 extend from a recess 143 defined by a floor 145 and a side wall 147 of a ring 150 which encircles the upper portion of the main body 141. The teeth extend radially from the side wall 147 (see FIG. 4A) inwardly to the edge of an opening 154 which extends longitudinally through the device and through which fluid flow is permitted. A circular groove 144 is disposed in the bottom of the device 140 and is configured to receive and hold a portion of a frangible diaphragm which closes off the opening 154 to fluid flow until it is broken.
Referring now to FIG. 5, a plug set and float shoe are shown according to the present invention. A top plug 210 is disposed above, but not yet in contact with, a bottom pluq 240. The bottom pluq 240 is disposed above, but not yet in contact with, a float shoe 300.
The top plug 210 is similar to the plug 10, previously described. The plug 210 has a body 212 with a plurality of wipers 214 extending therefrom. A non-rotation device 220 (like the non-rotation device 20) is threadedly engaged in an opening 216 in the bottom of the body 212 by threads 226 on the periphery of a main member 221 of the device 220. A plurality of teeth 222 extend from a recess 223 defined by a floor 225 and a side wall 227 of a ring 230 which encircles the top of the main member 221. The teeth 222 are like the teeth 22 and 142 previously described.
The bottom plug 240 is like the plug 40, previously described. The plug 240 has a body 242 with a plurality of wipers 244 extending therefrom. A non-rotation device 250 (like the non-rotation device 50) is threadedly engaged in an opening 246 in the bottom of the body 242 by threads 256 on the periphery of a main member 251 of the device 250. A plurality of teeth 252 extend from a recess 253 defined by a floor 255 and a side wall 257 of a ring 260 which encircles the bottom of the main member 251. The teeth 252 are like the teeth 52 and 142 previously described.
The plug 240 has a non-rotation device 270 (similar to the non-rotation device 70) which is threadedly engaged in an opening 276 in the top of the body 242 by threads 286 on the periphery of a main member 271 of the device 270. A plurality of teeth 272 extend from a recess 273 defined by a floor 275 and a side wall 277 of a ring 280 which encircles the top of the main member 271. The teeth 272 are like the teeth 72 and 142 previously described.
A circular groove 274 is disposed in the bottom of the main member 271. An upstanding shoulder 281 of a frangible diaphragm 282 is held in the groove 274 to maintain the diaphragm 282 in place over an opening 284 that extends longitudinally through the device 270. Fluid flow is permitted through the opening 284 when it is not closed off by the diaphragm 282.
The float shoe 300 has an outer tubular body 302 which is threadedly connected to a casing joint 287. An amount of hardened cement 303 surrounds a check valve 304 mounted substantially in the center of the float shoe 300. A non-rotation device 310 as shown is mounted on the check valve 304 in the cement 303, but it could be mounted so as not to contact the check valve.
The non-rotation device 310 has a main member 311 and a plurality of teeth 312 which extend upwardly from a recess 313 defined by a floor 315 and a side wall 317 of a ring 320 which extends around the top of the main member 311. The teeth 312 are like the teeth 72 and 142 previously described. An opening 314 extends longitudinally through the device 310 and permits fluid flow therethrough.
The check valve 304 itself is a typical prior art valve having a main body 310 with a plunger 306 that is urged upwardly by a spring 305 to close off flow through the valve by closing off a channel 308 in and through the valve body.
The opening 308 is in fluid communication with the opening 314 in the device 310, which itself is in fluid communication with the interior of the casing joint 287.
Pockets 316 and 318 in the main member 311 of the device 310 have cement 303 in them. The cement inhibits movement of the device 310 with respect to the cement 303, particularly during drill out.
A non rotation device 400 as shown in FIGS. 6a and 6b is similar to devices 100 and 140, previously described; but it has a load bearing ring 402 located centrally of the device around an opening 404 of a flow channel 406 through the device. The device 400 has a main body 408 with a threaded periphery 410 for threaded engagement with a female-threaded opening in another apparatus. A plurality of teeth 412 extend from a recess 414 defined by a floor 416, a side wall 418 of the ring 402 which encircles the opening 404, and a side wall 420 of a lip 422 extending around the device's outer periphery. The teeth 412 extend radially from the side wall 420 inwardly to the edge of the ring 402. The tip 424 of the lip 422 is tapered to a point. By using a reverse taper on an adjacent apparatus (e.g. a plug) better centering of two adjacent devices or apparatuses is achievable and a better seal may be obtained between the two.
Although the load members (rings) shown in these preferred embodiments are circular and continuous, it should be understood that it is within the scope of this invention to provide discrete upstanding members (one or more) which extend sufficiently upward from the recess of the device to take some or all of the load off of the teeth when two devices meet.
As shown in FIGS. 7a, 7b and 7c, teeth for an anti-rotation device according to the present invention may have a surface comprising a plurality of subsurfaces and an inwardly tapering lip may be engagement and sealing. Teeth 512 (shown to scale) of an anti-rotational device 500 according to the present invention have a body member 514 defined by a substantially straight side surface 509 and a surface 503 comprised of sub-parts 504, 505 and 506. The anti-rotation device 500 a main body member 516, a load bearing ring 518, and a recess 520. This device is similar to those previously described herein. It has an inwardly tapering lip 522 extending around the outer periphery of the recess 520.
In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein are well adapted to carry out the objectives and obtain the ends set forth at the outset. Certain changes can be made in the method and apparatus without departing from the spirit and the scope of this invention. It is realized that changes are possible and it is further intended that each element recited in any of the following claims is to be understood as referring to all equivalent elements for accomplishing substantially the same results in substantially the same or equivalent manner. It is intended to cover the invention broadly in whatever form its principles may be utilized. The present invention is, therefore, well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as others inherent therein. | Well apparatuses with device for preventing their relative rotation with respect to adjacent well apparatuses and anti-rotation devices for well apparatuses, including, but not limited to, plugs, float shoes, float collars, jars, and clutch devices for packers. In one embodiment a non-rotation device has a main member with a recess on which are disposed a plurality of teeth with a load member adjacent the teeth for bearing a load put on the device and for isolating the teeth from the load, the teeth extending beyond the recess. In one embodiment the teeth are configured, disposed, and profiled to facilitate their interengagement with other teeth and to contain between them foreign objects which might impede proper interengagement. In various embodiments plugs are provided with such anti-rotation devices. In various embodiments the load member is a continuous circular ring disposed about the apparatuses outer periphery or around the opening of a channel through the device. The load members may be non-continuous upstanding members. | 4 |
[0001] This application is related to HT05-013, filed on ______ as application Ser. No. ______ and is herein incorporated, by reference, in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to the general field of magnetic tunnel junctions (MTJs) with particular reference to the bottom electrode located between them and the inter-layer dielectric (ILD) of an integrated circuit.
BACKGROUND OF THE INVENTION
[0003] Magnetoresistive Random Access Memory (MRAM), based on the integration of silicon CMOS with Magnetic Tunnel Junction (MTJ)s, is a major emerging technology, highly competitive with existing semiconductor memories (SRAM, DRAM, Flash etc). The MTJ consists of two ferromagnetic layers separated by a thin dielectric layer. Magnetization of the two ferromagnetic layers can be arranged to be in either parallel (low resistance) or anti-parallel (high resistance) magnetization states, representing “1” and “0” respectively, The MTJ memory cells are usually inserted at the back end of a standard CMOS process. The high-speed version of MRAM architecture consists of a cell with an access transistor and a MTJ (1T1MTJ) in the array. The MTJ element is formed on top of the bottom conductor line, which is used to connect the base of the MTJ to the access transistor. Switching of the free layer magnetization in the MTJ device is accomplished by applying currents to orthogonal conductor lines.
[0004] The conductors are arranged in a cross-point architecture that provides the field for selectively switching each bit. One line (bit line) provides the field parallel to the easy axis of the bit, while another line (write word line) provides the perpendicular (hard axis) component of the field. The intersection of the lines generates a peak field that is engineered to be just above the switching threshold of that MTJ. For high performance MTJ devices, the separation between the write word line (bit line) and MTJ free layer is made as small as possible.
[0005] In a read operation, the read word line (RWL) is selected, and the transistor is turned on. This causes the MTJ device to be connected to ground. At this time, a sense current passes through the BL-MTJ-BE and to ground. The resistance of the MTJ device is low when the MTJ is storing a 1 and high when it is storing a 0.
[0006] Referring now to FIG. 1 a , shown there is tantalum hard mask 15 which will be used to separate MTJ sheet stack 16 into individual devices, each resting on a bottom electrode that comprises material from layer 17 which rests on SiN ILD 11 . Also seen (though not relevant to the invention) are vias 18 . In FIG. 1 b , layer 16 has been patterned into individual MTJ devices 4 , with Ta mask 15 having been partly consumed during the etch operation. In FIG. 1 c bottom electrode layer 17 has also been patterned into individual electrodes. However, in the course of making certain that said electrodes are truly electrically isolated one from another, ILD layer has been over etched so that its top surface has been partly eroded, as symbolized by its being shown as a broken line in the figure.
[0007] Reactive ion etching (RIE) has been preferred over IBE (ion beam etching) as the method for etching layer 17 . However, vertical features created by IBE always have an extended slope on the edge, which not only could creates electrical shorting problems but also limits further reduction of line width and make it impossible to make very high density IC device. In general, RIE is considered a better approach to creating well-defined three dimensional micro-features but there are several major problems currently associated with the RIE process:
[0000] (I) The uncontrollable over etch mentioned above is due to the lack of etching selectivity between the bottom electrode and the ILD. FIG. 2 illustrates the structure of layer 17 in greater detail—immediately on ILD 11 is TaN layer 12 on which is alpha tantalum layer 13 . Layer 14 comprises a second TaN layer.
(2) This etching process always results in a large amount of re-deposition all over the surface of the device due to the non-volatility of the reaction products.
(3) The MTJ will experience two etching processes (first in its own etch and then during the BE etch). This not only affects the MTJ's overall dimensions, but also results in serious damage to the edge of the MTJ's tunnel barrier layer.
[0008] A routine search of the prior art was performed with the following references of interest being found:
U.S. Pat. No. 6,974,708 (Horng et al) discloses OSL on top of the bottom electrode. U.S. Pat. No. 6,703,654 (Horng et al) teaches a NiCr/Ru bottom electrode. U.S. Pat. No. 6,960,48 (Horng et al) discloses a bottom electrode of /NiCr/Ru/α-Ta. U.S. Patent Application 2005/0254293 (Horng et al) teaches layers comprising NiCr/Ru/αTa. U.S. Patent Application 2005/0016957 (Kodaira et al), the Anelva Co., shows dry etching using CH 3 OH. U.S. Patent Application 2006/0002184 (Hong et al) teaches bottom electrodes of NiCr/Ru/Ta or NiCr/Rulα-TaN.
Other references, supplied by the inventor, are:
1. S. Tehrani et. al. “Magnetoresistive Random Access Memory using Magnetic tunnel junction” Proceeding of the IEEE. Vol. 91, p703-712, 2003. 2. C. Horng et. al. HTO3-022 “A novel structure/method to fabricate a high performance magnetic tunneling junction MRAM”. Magic touch and NiCr/Ru/alpha-Ta. 3. “Nanoscale MRAM elements” (including an extensive review of RIE), —S. J. Peraton and J. R. Childress (IBM and U of F).
SUMMARY OF THE INVENTION
[0018] It has been an object of at least one embodiment of the present invention to provide a process for forming a bottom electrode for an MTJ stack on a silicon nitride substrate in such a way as to minimize any possible surface damage to said substrate.
[0019] A further object of at least one embodiment of the present invention has been that said substrate also serve as an ILD of an associated integrated circuit and that said ILD have a thickness no greater than about 500 Å thereby facilitating it proximity to a word line of said integrated circuit.
[0020] Another object of at least one embodiment of the present invention has been that said bottom electrode have good electrical conductance.
[0021] Still another object of at least one embodiment of the present invention has been that said MTJ stack have vertical, or near vertical, sidewalls and be spaced no more than about 0.3 microns from neighboring MTJ stacks.
[0022] Yet another object of at least one embodiment of the present invention has been that said process not damage the edges of the tunnel barriers of said MTJ stacks.
[0023] These objects have been achieved by including a layer of ruthenium as one of the layers that make up the bottom electrode. The ruthenium serves two purposes. First, it is a good electrical conductor. Second, it responds differently from Ta and TaN to certain etchants that may be used to perform RIE. Specifically, ruthenium etches much more slowly than Ta or TaN when exposed to CF 4 while the reverse is true when CH 3 OH is used. Furthermore, silicon nitride is largely immune to corrosion by CH 3 OH, so removal of a ruthenium layer at, or near, the silicon nitride surface can be safely performed.
[0024] This differential etch behavior allows an included layer of ruthenium to be used as an etch stop layer during the etching of Ta and/or TaN while the latter materials may be used to form a hard mask for etching the ruthenium.
[0025] A problem of the prior art has been the relatively poor adhesion of ruthenium to silicon nitride. This problem has been overcome by inserting a bilayer of NiCr on TaN as the ‘glue’ between the Ru and the SiN.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1 a - 1 c show the prior art process for forming a bottom electrode for an MTJ stack.
[0027] FIG. 2 illustrates the layer structure of an MTJ bottom electrode of the prior art.
[0028] FIG. 3 illustrates the layer structure of an MTJ bottom electrode as used in the first embodiment of the present invention.
[0029] FIG. 4 shows the structure seen in FIG. 3 after CF 4 etching during which the Ru layer acts as an etch stop.
[0030] FIG. 5 shows the structure seen in FIG. 4 after CH 3 OH etching to remove Ru with minimum corrosion of the SiN substrate.
[0031] FIG. 6 shows the starting point for the process of the second embodiment of the invention.
[0032] FIG. 7 illustrates a key feature of the second embodiment, namely a protective coating that is partly consumed during etching of the alpha tantalum portion of the bottom electrode,
[0033] FIG. 8 illustrates the patterning of the protective coating prior to etching down to the level of the ruthenium.
[0034] FIGS. 9 and 10 show the final process steps whereby the SiN substrate on which the bottom electrodes lies suffers minimal corrosion after it is exposed and, furthermore, an amount of the protective coating is still present and is thus able to provide permanent protection to the structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The invention discloses a novel bottom conductor layer structure that is smooth, flat, and has low resistance. In the first embodiment, the bottom conductor layer structure is NiCr30/Ru20/α-Ta120/TaN150. In the second embodiment, the bottom conductor layer structures is typically TaN/NiCr3/Ru30/α-Ta120/TaN150. The total thickness of these bottom conductor structures is 300 Å (as in the prior art). RIE of these bottom conductor layers is first achieved using an etchant of the CF 4 type to remove the top TaN/Ta layer, which is followed by an etchant of the CH 3 OH type to etch the ruthenium.
[0036] In MTJ structures, topological roughness of the magnetic layers causes ferromagnetic coupling (Neel coupling) to shift the hysteresis loop. To minimize this inter-layer coupling effect, it is critical to form the MTJ stack on a flat/smooth bottom conductor. An example of a MTJ configuration that results in a high performance MTJ is:
[0000] SiN/TaN/NiCr45/Ru100/Ta150/S.E./NiCr5O/MnPt150/CoFe20/Ru7.5/CoFeB21/AlOx(10-15)/NiFe35/CAP. |<BE<∥<MTJ stack>| where S.E.=sputter etch
[0038] It is known that Ta formed on top of Ru grows in its a low resistance alpha-Ta phase. The high performance MTJ is formed on top of NiCr50/Ru100/Ta150 bottom conductor. The disclosed NiCr30/Ru20/Ta100/TaN150 bottom conductor of this invention is very flat and smooth (typically having a roughness value less than about 2 Å). The TaN150 cap is used here to protect Ta from oxidation. For the process to yield a high performance MTJ, this TaN cap is sputter-etched to a 30 Å thickness of the exposed TaN top layer.
[0039] When using a photoresist mask, the etching selectivity for Ta (TaN)/Ru by CF 4 -RIE is around 10. Thus in the process of using RIE to pattern the NiCr30/Ru30/Ta100/TaN150 bottom conductor, the top Ta/TaN is subjected to CF 4 gas chemistry which is largely ineffective at the Ru surface. After photoresist strip, the etchant is then changed to CH 3 OH to etch the remaining Ru/NiCr. Ru etch rate is about same as SiN and NiCr etch rate is about 0.5 of SiN. Since the NiCr/Ru seed layer is much thinner than ILD SiN (50 Å vs 300 Å), even with a 100% over-etch of the Ru30/NiCr30 layers, over-etching into the SiN would amount to less than 50 Å. In contrast, for CF 4 -RIE of the TaN501Ta100/TaN150 (as used in the prior art), a 100% over-etch would result in the removal of over 300 Å of the SiN ILD.
[0040] For the first embodiment, as an alternative to the use of NiCr as a ‘glue’ layer, a special treatment of the SiN substrate surface may be used instead:
[0000] Sputter-clean SiN/OSURu30/α-Ta120/TaN150
[0041] where OSL stands for oxygen surfactant layer. When OSL is used to treat the SiN surface, SiOxyNitride/RuO is formed at the SiN/Ru interface which then promotes good adhesion.
[0042] We now provide a description of the processes used to manufacture the two embodiments of the invention:
1 st Embodiment
[0043] Referring now to FIG. 3 , the process starts with sputter cleaning of the surface of substrate layer 11 , followed by depositing thereon layer of NiCr 10 onto which is deposited ruthenium layer 31 to a thickness between about 20 and 30 Angstroms. This is followed by the deposition, to a thickness between about 100 and 200 Angstroms, of alpha tantalum layer 32 (on ruthenium layer 31 ). Next, tantalum nitride layer 12 is deposited on layer of alpha tantalum 32 (to a thickness between about 100 and 150 Angstroms).
[0044] Now follows a key feature of the invention which is the process used to etch the bottom electrode sheet (layers 12 / 32 / 31 / 11 ) into individual bottom electrodes without, at the same time, significantly penetrating silicon nitride substrate 11 . This is accomplished in two main steps, as follows:
[0045] Referring now to FIG. 4 , photoresist mask 41 , that defines the required multiple electrode shapes, is formed on the upper surface of layer 12 . Then, a first reactive ion etching step is performed, using as the etchant one of several possible gaseous compounds of carbon and fluorine, such as CF4, CHF 3 etc., with CF 4 being preferred. Etching of all unprotected areas now proceeds at a rate of about 80 nm/min. and layers 12 , and 32 are successively removed (where there is no photoresist). When however, layer 31 of ruthenium becomes exposed, the etch rate falls off substantially—typically by a factor of about one 10 th , at which point reactive ion etching may be terminated “at leisure” with no danger of etching through ruthenium layer 31 and penetrating silicon nitride substrate 11 . The appearance of the structure is now as shown in FIG. 4 with arrow 42 pointing to the region of separation between two individual bottom electrodes.
[0046] Now moving to FIG. 5 , all remaining photoresist has been removed. At this point a second reactive ion etching process is initiated. In this case the etchant used is one of several possible gaseous compounds of carbon, oxygen, and hydrogen, such as CH 3 OH, CO+N H 3 , C 2 H 5 OH, etc., with CH 3 OH being preferred. No additional photoresist is required. Instead the previously etched layer 12 acts as a hard mask during the etching of layers 31 and 10 . Etching of all exposed ruthenium surfaces now proceeds at a rate of about 8 nm/min. until silicon nitride layer 11 is exposed, at which point the second reactive ion etching process may be terminated, also “at leisure”, with no danger of penetrating silicon nitride substrate 11 by more than about 60 Angstroms. The appearance of the structure is now as shown in FIG. 5 .
2 nd Embodiment
[0047] Referring now to FIG. 6 , the process of the 2 nd embodiment starts with sputter cleaning of the surface of SiN substrate layer 11 onto which is deposited layer of tantalum nitride 61 to a thickness between about 20 and 30 Angstroms. This is immediately followed by the deposition (onto the top surface of 61 ) of layer 62 of NiCr to a thickness between about 20 and 30 Angstroms. Note that it is critical for the effectiveness of this embodiment that layers 61 and 62 always be used together. The motivation for this is the excellent adhesion of TaN to SiN, the excellent adhesion of NiCr to TaN, and the excellent adhesion of Ru to NiCr. Furthermore, NiCr is an effective seed layer for Ru so it also serves to minimize the resistivity of Ru layer 63 .
[0048] Next, layer 63 of ruthenium is deposited on layer 62 and then alpha tantalum layer 64 is deposited on ruthenium layer 63 . Layers 61 - 64 now constitute a base layer on which MTJ devices can be formed. Seen in FIG. 6 are pinned layer sub-stack 65 , insulator tunneling layer 66 and free layer/capping layers 67 . The individual MTJ devices are formed by etching layers 65 - 67 (under a tantalum hard mask) by means of CF 4 —CH 3 OH, which etching process stops when alpha tantalum layer 64 is reached. The appearance of the structure after the individual MTJ devices have been formed is as illustrated in FIG. 6 .
[0049] Referring next to FIG. 7 , following the formation of the MTJ devices they are coated with conformal continuous layer 71 of a material known to protect the MTJ junction during the bottom electrode etch that follows. Suitable materials for this layer include SiO 2 , SiN, and SiN/SiO 2 , with SiO 2 being preferred. Moving on to FIG. 8 , once layer 71 is in place, photoresist layer 81 is applied over the entire surface and patterned so as to define the individual bottom electrodes, following which this pattern is transferred to layer 71 by etching its unprotected areas.
[0050] As shown in FIG. 9 , once all photoresist has been removed layer 71 becomes a hard mask suitable for etching alpha tantalum layer 64 . This is accomplished by means of a first RIE process based on one of several possible gaseous compounds of carbon and fluorine, such as CF 4 and CHF 3 , with CF 4 being preferred. It is important to note that the initial thickness of layer 71 is critical as it should be thin enough to provide good spatial resolution of the etched parts but thick enough so that there is always present a sufficient thickness to protect the areas that underlie it. This minimum remaining thickness should be about 600 Angstroms.
[0051] When layer 63 of ruthenium becomes exposed, the etch rate falls off substantially—typically by a factor of about 10, at which point first reactive ion etching may be terminated “at leisure” with no danger of etching through ruthenium layer 63 and penetrating silicon nitride substrate 11 . The appearance of the structure is now as shown in FIG. 9 with arrow 92 pointing to the region of separation between two individual bottom electrodes
[0052] The remains of layers 64 and 71 now serve as a hard mask for the removal of unprotected areas of ruthenium layer 63 , as well as layers 62 and 61 , by means of a second RIE process. The etchant used in the second reactive ion etching process is one of several possible gaseous compounds of carbon, oxygen, and hydrogen such as CO+NH 3 , CH 3 OH, and C 2 H 5 OH, with CH 3 OH being preferred. Once all exposed ruthenium has been removed, the etch rate drops by a factor of about ⅔ when silicon nitride substrate 11 becomes exposed, at which point the second reactive ion etching process may be terminated with minimal penetration of the silicon nitride substrate and with a non-zero thickness of conformal continuous layer 91 still present. This remnant of layer 91 can now serve as a protective layer for the structure.
[0053] In summary, the advantages of the invention include:
[0054] (a) It results in a well defined vertical profile for each MTJ
[0055] (b) It avoids re-deposition of etching by-products on the device surface
[0056] (c) It avoids any extensive over etching of the underlying thin SiN ILD.
[0057] (d) it avoids possible exposure of the underlying Cu word line, thereby avoiding Cu corrosion by the etching chemicals
[0058] (e) It provides an easily controlled manufacturing scheme for the bottom electrode layer of an MRAM device.
[0059] (f) It solves the problem of weak adhesion between the BE and ILD
[0060] (g) It provides a BE with good electrical conduction
[0061] (h) It protects the exposed MTJ junction during BE etch. | Formation of a bottom electrode for an MTJ device on a silicon nitride substrate is facilitated by including a layer of ruthenium near the silicon nitride surface. The ruthenium is a good electrical conductor and it responds differently from Ta and TaN to certain etchants. Adhesion to SiN is enhanced by using a TaN/NiCr bilayer as “glue”. Thus, said included layer of ruthenium may be used as an etch stop layer during the etching of Ta and/or TaN while the latter materials may be used to form a hard mask for etching the ruthenium without significant corrosion of the silicon nitride surface. | 6 |
TECHNICAL FIELD
The present disclosure is directed, in general, to batteries, and more specifically, to a system and method for applying a plurality of energy pulse to a cathode for rapid depolarization of batteries.
BACKGROUND OF THE DISCLOSURE
Some non-rechargeable batteries, like LiSO2 (lithium sulfur dioxide), exhibit the phenomena of anode passivation and cathode polarization. These phenomena reduce the voltage that is immediately available in the battery in what is known as “voltage delay.” When feeding a switching power, or a similar device operating in constant power mode, a reduction in such available voltage forces an additional current in the battery that even further reduces the available voltage. Additionally, cold temperatures can exacerbate the negative effects of such phenomena. Such occurrences prevent desired battery operation.
SUMMARY OF THE DISCLOSURE
To address one or more of the above-identified deficiencies of the prior art, one embodiment of the disclosure is a system for conditioning a battery and includes a pulse generator and a use sensor. The pulse generator is configured to apply either a single or a plurality of energy pulses to a polarized cathode of a battery and a passivated anode of the battery by selectively either shorting the battery across the polarized cathode and the passivated anode, or causing a current flow limited by an external element, for a duration of time. The energy pulses at least partially depolarize the polarized cathode and at least partially depassivate the passivated anode. The use sensor is configured to detect a use of the battery with a device and communicate the detected use to the pulse generator. The pulse generator automatically applies the pulses upon receipt of the detected use. The depolarization/depassivation can also be applied at any time prior to actual use of the battery in the designated application, as a part of the preventive maintenance.
Certain embodiments of the disclosure may provide numerous technical advantages. For example, a technical advantage of one embodiment may include the capability to depolarize a cathode by applying high current, short duration pulses thereto. Other technical advantages of other embodiments may include the capability to automatically apply high current, short duration pulses to a cathode of a battery upon turn-on of a device utilizing the battery in order to depolarize the cathode of the battery and achieve maximum voltage quickly. Yet other technical advantages of other embodiments may include the capability to both depassivate and depolarizes the battery quickly. Still yet other technical advantages of other embodiments may include the capability to both depassivate and depolarizes the battery on demand at low temperatures.
Although specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages. Additionally, other technical advantages may become readily apparent to one of ordinary skill in the art after review of the following figures and description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
FIGS. 1A and 1B illustrate a conventional battery and negative effects that may occur thereto over time;
FIG. 2 is a chart, illustrating the relationship of current and resistance, according to an embodiment of the disclosure;
FIG. 3 illustrates an energy pulse generator, according to an embodiment of the disclosure;
FIG. 4 illustrates a process of reconditioning a battery with energy pulses, according to an embodiment of the disclosure;
FIG. 5 illustrates reconditioning components that may be associated with the process of FIG. 4 , according to embodiment of the disclosure;
FIG. 6 illustrates a behavioral electrical model, according to an embodiment of the disclosure;
FIG. 7 illustrates use of said model in a computer simulation, according to an embodiment of the disclosure;
FIG. 8 is a chart that corresponds to the model of FIG. 7 ; and
FIG. 9 is an embodiment of a general purpose computer that may be used in connection with other embodiments of the disclosure to carry out referenced functions.
DETAILED DESCRIPTION
It should be understood at the outset that, although exemplary embodiments are illustrated below, the present invention may be implemented using any number of techniques, whether currently known or not. The present invention should in no way be limited to the example implementations, drawings, and techniques illustrated below, and no such limitation is intended. Additionally, the drawings are not necessarily drawn to scale.
FIGS. 1A and 1B illustrate a conventional battery 100 and negative effects that may occur thereto over time. For purposes of illustration, the battery 100 will be described with reference to a non-rechargeable LiSO 2 (lithium sulfur dioxide) battery. Although a particular type of battery will be disclosed herein, it should be understood that the teachings of the disclosure may also be applied to other batteries or electrochemical processes that are bilateral in nature and tend to corrode. Further, although the pulse techniques disclosed herein are particularly applicable to non-rechargeable batteries, they may also be used with rechargeable batteries for the purpose of rapid recharging of the battery at an effective rate shorter than that achievable with an equivalent average DC charging current. Since a chemical reaction is taking place during charging, and the reactivity of materials participating in the reaction, as enumerated by the probability of the materials to both shed, or accept an electron, is generally a function of impulse energy, or, equivalently, high frequency of the charging energy, applied to the reaction site, then the time to transpose a volume of electrons from one electrode to another is shorter when a plurality of high di/dt pulses is applied in preference to DC current.
The battery 100 in FIG. 1 includes an anode 110 , a cathode 120 , and an electrolyte 130 . In a LiSO 2 battery, the anode 110 is lithium; the electrolyte is SO 2 , which due to high pressure is liquefied; and the cathode 120 includes a carbon rod 122 surrounded by a carbon porous material 124 . The porous material 124 provides a larger surface area in which electrons can flow, thereby providing a large emitting surface.
As will be recognized by one of ordinary skill in the art, the anode 110 undergoes oxidation and releases free electrons while the cathode 120 accepts electrons and undergoes a reduction. The electrons are passed through a load current flow 140 to the porous material 124 . Additionally, an internal current flow 150 exists in which the cathode 120 creates ions that are passed to the electrolyte 130 and the anode 110 .
Over time, due in large part to the internal current flow 150 , the above two referenced phenomena—passivation and polarization—occur. Both can occur while the battery 100 is sitting on a shelf.
During passivation, the anode 110 is coated with a thin layer of non-conductive Li2SO 4 (lithium sulfate). With reference to FIG. 1B , the surface 112 of the anode 110 can take on the appearance of rough dendritic spikes 114 . This coating causes the internal current flow 150 to fall. In particular configurations, passivation of the battery 100 can occur in a matter of hours. Depending on the particular type of battery, the rate of passivation may change.
During polarization, the porous material 124 accumulates various reactants, ion clusters, and charges, thereby reducing available cathode voltage and electron mobility or conductivity. In particular configurations, polarization may be a slower process and occur over a matter of weeks. Depending on the particular type of battery, the rate of polarization may change.
In addition to the above passivation and polarization phenomena, cold temperatures can negatively affect the battery 100 by causing the electron mobility of the electrolyte 130 to decrease. In such scenarios, the electrolyte 130 may congeal or gel, causing the electrolyte 130 to act like a high viscosity material reducing electron mobility therethrough. Depending on the components of the battery, the negative effects of low temperature may be more or less detrimental.
In conventional scenarios, a battery may partially depassivate and depolarize over a matter of hours. In such scenarios, an immediate voltage is diminished and may not be within a desired range until hours of time have passed to allow partial depassivation and depolarization. Such a delayed process not only wastes time, but also wastes energy in the battery 100 . Cold temperatures further exacerbate such problems, causing additional time for a battery to reach its optimal operating condition—if it even reaches such an operating condition.
Given such problems, certain embodiments disclose the application of high current and short duration energy pulses to the battery 100 . These energy pulses shatter and break the passivation layer on the anode 110 and rapidly exite the cathode 120 to remove the polarization gunk (reactants, ion clusters, and charges) on the cathode 120 . In particular embodiments, the high current and short duration pulses quickly depassivate and depolarize the battery, allowing operation with a desired voltage in a matter of seconds as opposed to hours.
In particular embodiments, these energy pulses are applied automatically and on-demand when a current for use of the battery is detected. In other configurations, these energy pulses are applied automatically and on-demand when the battery is below a certain temperature and use of the battery is detected.
FIG. 2 is a chart 200 , illustrating the relationship of current and source resistance of the battery, according to an embodiment of the disclosure. In the chart 200 , the x-axis 240 represents current in Amperes while the y-axis 250 represents normalized resistance. There are three examples charted: (1) one at −40 degree Celsius (represented by line 210 ), (2) one that has been sitting idle for one week at ambient temperature (represented by line 220 ), and (3) one that is at ambient temperature (represented by line 230 ). Looking at just the three lines 210 , 220 , and 230 , one can see that the older the battery is, the more resistance that builds up. Additionally, colder batteries have increased resistance. The chart 200 will scale with the size of battery, and/or a number of cells stacked in series.
In an ideal battery, resistance would be zero. However, as will be recognized by one of ordinary skill in the art, batteries have a static ohmic resistance. In addition to such static ohmic resistance, there is also resistance from the above-described cathode polarization and anode passivation.
The chart 200 illustrates that resistance decreases as the current increases for every battery charted. At roughly 15-20 amperes, the lines 210 , 220 , and 230 begin to converge and become more horizontal, indicating that the effects of passivation and polarization are diminished and that only ohmic resistance remains.
Particular embodiments of the disclosure avail from the above-described phenomena. However, instead of a continuous DC current, a high di/dt (change in current over a change in time) pulse train is applied, which may also be an electrical short applied across the cathode and anode for a short duration of time. The pulses are more effective at depassivating and depolarizing the battery.
As one of ordinary skill in the art will appreciate for example with a C-sized battery, currents above 10 amps are typically not applied in a battery. Accordingly, the current energy pulses may be multiples of times higher than an amplitude of a nominal current of the battery while in use with a device
FIG. 3 illustrates a pulsing generator 300 , according to an embodiment of the disclosure. Many of the disclosed circuit components in the pulsing generator 300 will become apparent to one of ordinary skill in the art; accordingly, for purpose of brevity, the interaction of every circuit element will not be explicitly described. The pulsing generator 300 includes a block 310 that produces a train of signals or pulses, which should not be confused with the energy pulses for the cathode and anode. In particular embodiments, the block 310 may be a voltage controlled oscillator. The train of signals are applied to a switch 320 or M 1 that when activated applies a selective short across the battery 330 —a pulse. Any of a variety of switches can be used, including switches that cause an action when a signal is received and switches that cause an action when a signal is not applied. Also shown are resistors R 1 , R 2 , R 3 , R 5 , R 6 , and R 7 ; capacitors C 1 , C 2 , and C 3 ; a diode element D 1 ; and a thermistor 340 .
As referenced above, at lower temperatures, the afore-mentioned problem with polarization and/or passivation become pronounced in part due to a gelling of the electrolyte. Therefore, according to some embodiments, the pulse generator 300 may measure the temperature and only switch on if below a certain threshold temperature.
Although a particular circuit has been provided for a pulse generator 300 in FIG. 3 , any of a variety of other configurations may be utilized for a pulse generator, including those with more, less, or different component parts. Examples of components that may be used for the pulse generator in certain embodiments are provided below in FIG. 9 .
An alternative embodiment may consist of the Positive Temperature Coefficient (PTC) switching element, that may be constructed either as a simple fuse, or a thermostatic switch, or a more complex electronically controlled switch, and hereinafter referred to as the “fuse”, applied across the battery to produce a effectively a short pulse when the battery is connected to the load. The fuse resistance at and below ambient temperature is low, thereby forcing a large short current. After a short thermal time constant, a parameter of value specific to the PTC fuse selected, the fuse will reach a trip temperature, typically around 150 degC, at which point the resistance would increase dramatically, thereby arresting further current flow through the fuse, and terminating the pulse. Depending on the construction of the “fuse” a small amount of current may, but does not have to, continue to flow through the fuse after the trip, as required to maintain its temperature above the trip temperature—the value depends on the battery voltage operating voltage. FIG. 4 illustrates a process 400 of reconditioning a battery with energy pulses, according to an embodiment of the disclosure. FIG. 5 illustrates reconditioning components 500 that may be associated with the process 400 of FIG. 4 , according to an embodiment of the disclosure. The lines between each respective component 500 may represent any suitable communication of information—be it via circuit, a communication bus, or other suitable communication medium. The process 400 will be described with reference to both FIGS. 4 and 5 .
The process 400 may begin with detecting a use of the battery 510 at step 410 . This may occur through a use sensor 560 that either detects, for example, current flow in the battery 510 or current flow in a device 550 that utilizes the battery 510 for operation.
In particular configurations (although not every configuration), the process 400 may also determine whether a temperature measured by a temperature sensor 530 is below a predefined threshold. As referenced above, in particular configurations the problems with polarization and/or passivation may be more pronounced with cold temperatures. Accordingly, in certain configurations, the process may only proceed if the temperature is below a certain level as indicated by decisional step 420 . In such configurations, the temperature sensor 530 may communicate information to the pulse generator 520 . Either the temperature sensor 530 or the pulse generator 520 may determine whether the temperature is below a temperature threshold. In other configurations, step 420 may not occur and the process 400 may simply move on to step 430 .
At step 430 , a plurality of high current energy pulses may be applied on the battery to depassivate and depolarize the battery. A pulse generator 520 may initiate the plurality of energy pulses using information gathered from one or both of the temperature sensor 530 and user sensor 560 . The pulse generator 520 may be the pulse generator 300 of FIG. 3 . Alternatively, the pulse generator 520 may be any other suitable device that can initiate and/or apply an energy pulse on the anode and cathode.
The high current may be a shorting of the cathode and anode for a short duration of time. With regards to the anode, the high current, short duration energy pulses apply an electric field that shatters and break the dendritic spikes of the passivation layer, thereby exposing clean lithium, for example, in a LiSO 2 battery.
With regard to the cathode, the high current, short duration energy pulses, rapidly excite the polarization gunk (reactants, ion clusters, and charges) clogging the pores of the cathode. These high current, short duration energy pulses cause the polarization gunk to break apart and be effectively dislodged from the pores of the cathode material.
In particular embodiments, the circuitry for the pulses may be part of the load circuitry of the battery, allowing the short across the anode and the cathode.
In particular embodiments, the rate of the energy pulses may be 1000 times per second (1 kHz) with each pulse lasting 100 microseconds. In other embodiments, the rate may be more than or less than 1 kHz with each pulse lasting more than or less than 100 microseconds. In particular embodiments, the current is normally limited by source resistance of the battery and may exceed 20 Ampere. In other embodiments, the current peaks may be purposely limited via elements external to the battery, to maintain the RMS current below a desired value.
In particular configurations, the high current energy pulses may all be of similar amplitude. In other configurations, the high current pulses may be of varied amplitude, for example, as described below with reference to FIGS. 7 and 8 .
After application of a set of high current pulses, the process may determine at decisional step 440 whether or not more pulses should be applied. In particular configurations, pulses may be applied for a preset amount of time. In other configurations, a feedback sensor 540 measures parameters of the battery 510 that may be assessed for such a determination. For example, energy pulses may be applied and the voltage measured such that when diminishing returns on the energy pulses are measured, the energy pulses are no longer applied.
As a non-limiting example, in an ideal battery with no resistance, an observed voltage across a load of the battery should be a theoretical maximum. However, due to the ohmic resistance, passivation, and polarization, the observed voltage is less than theoretically achievable at given load current and battery temperature. Accordingly, one can measure the degree to which depolarization and depassivation have occurred by observing how close the voltage for a pulsed short across the battery is to the theoretical value. This observed voltage can be measured by the feedback sensor 540 . Such a feedback may be used to determine the number of pulses.
When a determination has been made not to continue, the process ends and the battery 510 may be used as normal with maximum voltage. Once again, in particular configurations, the determination may simply be that a maximum time has elapsed.
In particular embodiments, the steps of process 400 may be completely transparent to a user and occur automatically. As an example illustration, a battery 510 may be used in a flash light or with a variety of other devices 550 . When a user turns on the flashlight or other device 550 , the process 400 may automatically be initiated with the pulses being rapidly applied to the battery 510 . Then, the pulses stop and the flashlight or other device 510 is used as normal with a desired voltage.
FIG. 6 illustrates a behavioral model 600 of the battery, according to an embodiment of the disclosure. Like FIG. 3 , many of the disclosed circuit components in the model 600 will become apparent to one of ordinary skill in the art; accordingly, for purpose of brevity, the interaction of every circuit component will not be explicitly described. The model 600 is consistent with the observed behavior of the source resistance of the battery as illustrated in FIG. 2 , and includes a simulated cathode polarization element 610 (represented by a diode element D 1 and a voltage dependent resistance element M 2 ), a simulated anode passivation element 620 (represented by diode element D 2 and a voltage dependent resistance element M 1 ), a current sensing input 630 , a battery 640 , and an output 660 . Also shown are resistors R 1 , R 2 , and R 3 ; capacitors C 1 , C 2 , and C 3 acting as time delays affectuating M 1 and M 2 . As can be seen in the model 600 of FIG. 6 , the current sensing input 630 makes both the simulated cathode polarization element 610 and the simulated anode passivation element 620 a function of current. The higher the current, the more conductive the simulated cathode polarization element 610 and the simulated anode passivation element 620 become and more perfect the battery 640 becomes. Although the model 600 of FIG. 6 simulates what is happening with polarization and passivation, the model 600 of FIG. 6 does not necessarily simulate a pulsating current, which are simulated with reference to FIG. 7 below.
FIG. 7 illustrates the use of model 600 in simulation as model 700 , according to an embodiment of the disclosure. FIG. 7 is similar to FIG. 6 except that pulses are represented by the current element 780 . Also shown are resistors R 1 , R 2 , and R 3 ; capacitors C 1 , C 2 , and C 3 ; a simulated cathode polarization element 710 (represented by diode element D 1 and element M 2 ); a simulated anode passivation element 720 (represented by diode element D 2 and element M 1 ); and a voltage to current converter element 780 imposing a load on the battery as commanded by voltage sources 760 , 770 . For convenience, element 780 has a voltage to current transfer function of ⅕ or 0.2
FIG. 8 is a chart 800 that corresponds to the model 700 of FIG. 7 . The chart 800 shows time (in seconds) on the x-axis 810 ; voltage (in volts) on the left y-axis 820 and applied current (in amperes) on the right y-axis 830 . The top line 840 represents voltage while the bottom line 850 represents the current applied. In an ideal battery with no resistance, 3 Volts would be returned. However, there is both static ohmic resistance and resistance from passivation and polarization. Moving from left to right on the graph, an initial application of applied current at pulses of 1 amperes immediately decreases the voltage as indicated by arrow 842 , which represents depassivation. After arrow 842 , one can see a partial recovery as a result of depassivation. The amplitude of the current pulse increases at approximately 0.2 seconds to 2 amperes and at arrow 844 , one can see that depolarization is starting to take effect where a voltage increases while the current applied remains unchanged. At arrow 846 , he magnitude of the applied current decreases back to 1 Ampere while voltage increases to a value greater than that at arrow 842 for same load current of 1 Ampere, indicating a lower source resistance of the battery due to at least partial removal of the polarization charge. Finally, the magnitude of the applied current decreases again at approximately 1.6 seconds where voltage again increases to the open load value to complete the simulation interval. FIG. 9 is an embodiment of a general purpose computer 910 , the components of which may be used in connection with other embodiments of the disclosure to carry out any of the above-referenced functions. The general purpose computer 910 may generally be adapted to execute any of the known OS2, UNIX, Mac-OS, Linux, Android and/or Windows Operating Systems or other operating systems. The general purpose computer 910 in this embodiment includes a processor 912 , a random access memory (RAM) 914 , a read only memory (ROM) 916 , a mouse 918 , a keyboard 920 and input/output devices such as a printer 924 , disk drives 922 , a display 926 and a communications link 928 . In other embodiments, the general purpose computer 910 may include more, less, or other component parts. Embodiments of the present disclosure may include programs that may be stored in the RAM 914 , the ROM 916 or the disk drives 922 and may be executed by the processor 912 in order to carry out functions described herein. The communications link 928 may be connected to a computer network or a variety of other communicative platforms including, but not limited to, a public or private data network; a local area network (LAN); a metropolitan area network (MAN); a wide area network (WAN); a wireline or wireless network; a local, regional, or global communication network; an optical network; a satellite network; an enterprise intranet; other suitable communication links; or any combination of the preceding. Disk drives 922 may include a variety of types of storage media such as, for example, floppy disk drives, hard disk drives, CD ROM drives, DVD ROM drives, magnetic tape drives or other suitable storage media. Although this embodiment employs a plurality of disk drives 922 , a single disk drive 922 may be used without departing from the scope of the disclosure.
Although FIG. 9 provides one embodiment of a computer that may be utilized with other embodiments of the disclosure, such other embodiments may additionally utilize computers other than general purpose computers as well as general purpose computers without conventional operating systems.
Several embodiments of the disclosure may include logic contained within a medium. In the embodiment of FIG. 9 , the logic includes computer software executable on the general purpose computer 910 . The medium may include the RAM 914 , the ROM 916 , the disk drives 922 , or other mediums. In other embodiments, the logic may be contained within hardware configuration or a combination of software and hardware configurations. The logic may also be embedded within any other suitable medium without departing from the scope of the disclosure.
Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, “each” refers to each member of a set or each member of a subset of a set.
To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke paragraph 6 of 35 U.S.C. Section 112 as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim. | According to an embodiment of the disclosure, a system for conditioning a battery include a pulse generator and a use sensor. The pulse generator is configured to apply a plurality of energy pulses to a polarized cathode of a battery and a passivated anode of the battery by selectively shorting the battery across the polarized cathode and the passivated anode for durations of time. The plurality of energy pulses at least partially depolarize the polarized cathode and at least at least partially depassivate the passivated anode. The use sensor is configured to detect a use of the battery with a device and communicate the detected use to the pulse generator. The pulse generator automatically applies the plurality of energy pulses upon receipt of the detected use. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to radiation receivers with a photodetector and a sensor, and also to a method of operating the same, and a rangefinder with such a radiation receiver.
TECHNICAL FIELD
A laser ceilometer with a device for reducing the radiation emitted by the laser ceilometer is known from U.S. Pat. No. 4,288,158. As soon as the direction of the laser ceilometer deviates by more than a predetermined angle from the vertical position, the angle being detected by a sensor, the radiation emitted by the laser ceilometer is reduced. It is thereby ensured that a radiation intensity emitted by the laser ceilometer and by which the human eye could be damaged is no longer emitted as soon as the direction of the laser ceilometer deviates from the vertical position by a predetermined amount whereby the possibility exists that the radiation of the laser ceilometer can enter the human eye.
A method is known from DE 43 25 139 C1 for preventing eye damage during the use of high power lasers. In this method, or with the apparatus known from this document, the radiation of a warning laser is superposed on the radiation of a high power laser. The radiation intensity of the warning laser is increased such that an observer's eyelid would be excited to close due to the radiation intensity emitted by the warning laser before a radiation intensity dangerous for the observer's eye is emitted by the high power laser.
A system and a method are known from U.S. Pat. No. 4,552,454, in particular for testing laser rangefinders. In this system for testing laser rangefinders, the radiation emitted by a transmitter is first coupled into a device with reflecting surfaces. The radiation is focused by this device on a ray input of a glass fiber, which is provided centrally and at the end with reflecting surfaces. The radiation is at least partially reflected at these reflecting surfaces and is conducted to a receiver by this system provided with reflecting surfaces. A calibration of the rangefinder can be carried out by means of this arrangement, based on the known path difference between the surfaces provided centrally in the fiber and at the end in the fiber.
Rangefinders are furthermore known which have a laser as the radiation source, the range being determined using the radiation reflected back. For this purpose, a radiation receiver is allocated for the back-reflected radiation.
Since the receiver of the present rangefinders has an extremely small surface, in order to attain a high detection sensitivity, problems of optical destruction occur more and more frequently in the present rangefinders. The receiver surface has a diameter of only just 70 μm in some cases. The receiving optics of such a rangefinder is designed so that the whole of the radiation within the visual field and striking the entrance aperture is collected onto the receiver. Thus even very low radiation powers or radiation densities in the entrance aperture can lead to an optical destruction of the detector. A particular danger arises, in particular, from the high peak pulse power, which can be in the megawatt range, emitted by the rangefinder. Reflections of the transmitted beam at back-reflecting targets situated near to the device, or at targets with a high retroreflected fraction, lead as a rule to destruction of the receiver.
Even the radiation produced in the device itself can lead to destruction of device components due to back-scattering under unfavorable conditions.
SUMMARY OF THE INVENTION
The invention has as its object to provide a radiation receiver and a method of operating the same so that a destruction of device components, particularly of the photodetector, by self-radiation and extraneous radiation is prevented.
A further object of the invention is to provide a radiation receiver or a rangefinder with a radiation receiver which is immediately available for measuring operation after a radiation input which is harmful to the radiation receiver.
The object of the invention is attained by a radiation receiver comprising a photodetector, a sensor, a shutter arranged before the photodetector, and a delay device arranged before the shutter. The sensor receives radiation intensity. The shutter is driven in dependence on detected incident radiation intensity. The incident radiation is supplied to the photodetector via the delay device. The object of the invention is also attained by the method for operating the radiation receiver.
By the measure of providing a delay device, it can be ensured that a shutter arranged before the radiation receiver is closed before the radiation incident on the radiation receiver can pass the shutter and reach the photodetector unhindered. A sensor is provided for the determination of the radiation intensity of the incident radiation, and is arranged such that as rapid as possible closing of the shutter can be attained.
It has been found to be advantageous for the determination of the radiation intensity to couple out a fraction, preferably less than 5%, of the incident radiation and to conduct it to the sensor. A beamsplitter has been found to be particularly advantageous for the coupling-out.
If the incident radiation is coupled into an optical fiber, particularly by means of a convergent optics, a fiber branch can be used for branching off a fraction of the radiation intensity. The use of optical fibers is advantageous because distortion due to objects intruding laterally into the beam path is prevented and it is easy to conduct the radiation on a non-linear path, thus giving space-saving advantages.
It has been found to be advantageous to provide an optical fiber as a delay device. In such optical fibers, radiation can be conducted with small losses. It is also possible to arrange an optical fiber in a curved shape without incurring considerable radiation losses. The radiation can thus be conducted in the optical fiber with small losses. The possibility of conducting the radiation on curved paths contributes greatly to the compactness of the radiation receiver.
It has been found to be advantageous to use a shutter, which has an electro-optical substance. Such electro-optical substances, such as e.g. liquids and particularly crystals, rapidly change their optical properties when an applied potential is changed and thus have an outstandingly short reaction time.
It has been found to be advantageous to provide a shutter, which includes a filter with variable absorption properties, or several filters with different absorption properties. It is thereby possible to damp the incident radiation in dependence on the detected radiation intensity by means of the shutter or by selection of the corresponding shutter, so that the radiation reaching the photodetector does not exceed the maximum permissible intensity. By feedback of information from the shutter to an evaluation electronics allocated to the photodetector, the degree of damping effected by the shutter can be taken into account by the evaluation of the obtained data. The range of use of the radiation receiver can thereby be considerably enlarged.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in detail hereinafter using an embodiment.
FIG. 1 shows a schematic diagram of a rangefinder with a radiation receiver;
FIG. 2 shows a schematic diagram of the method with a rangefinder, and
FIG. 3 shows a schematic diagram of an electro-optical shutter.
DETAILED DESCRIPTION OF THE INVENTION
The radiation receiver 5 shown schematically in FIG. 1 includes a convergent optics 7 , by means of which the radiation of a radiation input 6 or of the entrance aperture is collected. An input beam is generated by this convergent optics 7 . A portion of the radiation from this input beam is supplied to a sensor 11 by means of a beamsplitter 9 or by means of a fiber branch 10 as shown in FIG. 2 . The signals of this sensor 11 are passed on to a control 13 by means of which the radiation intensity of the input beam is determined. If the value of the intensity of the input beam determined by the control 13 exceeds a predetermined value of a maximum permissible radiation intensity for the photodetector, a shutter 19 is driven to close. A reaction time between the radiation input with the sensing of the radiation intensity and the closing of the shutter 19 is given. To ensure that no damaging radiation intensity can reach the photodetector 22 , the portion of the input beam which is not supplied to the sensor 11 is coupled into a delay device 15 , here an optical fiber 17 . At least a minimum time is required for the transmission by the optical fiber 17 , and corresponds at least to the reaction time. Since the reaction time depends on how long the system requires to detect a high radiation intensity and close the shutter 19 , the minimum time also depends on these parameters.
It can be provided that an absorber is pivoted in as a portion of the shutter, and due to it the radiation intensity is reduced to a permissible amount for the photodetector 22 . It can also be provided that an absorber arranged in the beam path or before the photodetector 22 is first correspondingly activated, in dependence on the detected radiation intensity.
It can furthermore be provided to couple the radiation out of the radiation receiver 5 , e.g. by means of a switchable mirror, before the radiation can reach the photodetector 22 .
If the shutter 19 is opened, the light beam leaving the optical fiber 17 passes through the shutter 19 and is preferably supplied to the photodetector 22 via a transformation optics 21 . The transformation optics 21 is optional, and it is also possible that the radiation passing through the shutter 19 falls directly on the photodetector 22 . The signals generated by the photodetector 22 are supplied to an evaluation electronics 14 . If the radiation receiver 5 is installed in a rangefinder device, a laser 3 is allocated to the radiation receiver 5 as a radiation source. It can be provided that this laser 3 is likewise driven by the control 13 which is a part of the evaluation electronics 14 .
A method of protection of the radiation receiver 5 , in particular of a range finder, is described using specific values in FIG. 2 . The detailed values of power and destruction threshold are to be understood as values given by way of example, and are not limitative. An impression is to be given by these exemplary values of what an embodiment can look like and how far-reaching the associated protective function is.
An optical fiber is arranged behind the convergent optics at a place where the photodetector would otherwise be situated. In the embodiment example shown in FIG. 2, the sensor 11 is installed behind a fiber branch. The sensor 11 is exposed to 1% of the radiation input power through this fiber branch 10 . It is however also possible to provide the sensor directly in the free beam path, particularly in the input region.
The remaining radiation power of 99% of the input beam passes via the long optical fiber 17 , which functions as a delay device 15 , to an electro-optical shutter 20 . This electro-optical shutter 20 is described using FIG. 3 . The photodetector (no longer shown) of the rangefinder is situated behind the electro-optical shutter 20 .
The following data are used hereinafter as a basis:
Transmitter pulse duration: 3 ns
Energy of the transmitter laser pulse: about 20 mJ
Destruction threshold of the fiber material: 1.5 GW/cm 2
Destruction threshold of the electro-optical shutter: 100 MW/cm 2
Destruction threshold of the receiver: 500 watt peak pulse power
Switching time or delay time (delay between the onset of radiation intensity above the permissible peak pulse power and the closing of the electro-optical shutter): 50 ns
Peak pulse power of the transmitting laser about 7 MW
For a good signal transmission a step index fiber is used as the entrance fiber. The fiber cross section is dimensioned such that the full transmitted pulse power should fall on the fiber without causing any destruction.
From the destruction threshold of the fiber material and the transmitted pulse power, there is obtained from I max = P max 0.25 * ∏ * d 2 ⇒ d = 4 × P max I max × ∏
transmitter pulse power, I max being the peak pulse power of the transmitting laser and P max being the destruction threshold of the fiber material. In the determination of 770 μm, it is assumed that the optical power is uniformly distributed over the fiber.
Such fibers are obtainable as state of the art components on the market. The permissible bending radii are about 30 cm, specific to the producer. Bending radii below 10 cm with long-term stability can be obtained by tempering.
The nominal bandwidth of such step index fibers is usually about 10 MHz/km. The fiber loss is about 0.008 dB/m. The refractive index n of the quartz core at 1575 nm is about n≈1.44. The numerical aperture is about 0.22.
To ensure a delay time of Δt≈50 ns, the length of the fiber delay line must be about l=10 m. The following holds: C h = c n
with c=speed of light=3×10 8 m/sec
h=refractive index of the fiber material=1.44
With the fiber data from our embodiment example, there is obtained BW Fiber ( l ) = BW FIber I Fiber Δτ = 0.3 - 0.5 BW
a pulse broadening of about 0.5 ns over the path of 10 m, BW Fiber being the bandwidth and l fiber being the length of the fiber in Km. The signal is scarely effected by the delay device or the optical fiber, because of the short length of the fiber in km.
The fiber branch is designed so that 1% of the input radiation is conducted to the sensor. The sensor 11 then has to respond to a power of 5 W. Such sensors which react to such a high response threshold, are obtainable at a favorable cost as standard components. For example, a very fast photodiode with a small active surface and a pulse rise time <0.5 ns is used.
The response threshold of the sensor 11 is converted with a comparator into a digital trigger signal for the electro-optical shutter. In such an arrangement, the reaction time conditioned by the sensor 11 is a few ns.
The electro-optical shutter shown in FIG. 3 blocks the signal to the photodetector on receiving the trigger signal of the sensor 11 .
With the destruction threshold of the electro-optical shutter of {fraction (1/15)} the destruction threshold of the fiber, the beam leaving the fiber has to be expanded to a beam having a beam diameter greater by a factor of 4. Then: P max P max Shutter = 1.5 GW 100 MW = r 2 ( 0.5 × 770 nm ) 2 ⇒ r ≈ 1.52 mm
As electro-optical substances or electro-optical crystals, two lithium niobate crystals, each with 3.1 mm free aperture, can for example, be used.
The permissible transmission with the shutter blocked is to be T Shutter <0.7×10 −4 , so that the destruction threshold of the photodetector is not attained by the radiation passing through the shutter. P MAx , Sensor ≥ T Shutter × P max ; T Shutter < 500 Watt 7 M Watt
The transmission with the electro-optical shutter opened can be in the region of T>80%.
The electro-optical crystals can be constructed such that the electro-optical shutter is completely closed without the application of an electrical field to the crystals. When the rangefinder is set in operation, an electrical field is applied to the crystals so that a 90° rotation of polarization is attained, and the electro-optical shutter becomes fully transparent. On receiving a trigger signal from the sensor 11 , the field electrodes are grounded and, after the threatening light power has disappeared, are adjusted up again to the nominal potential.
The switching process is associated only with a slight charge reversal, and on average practically no power is thus required for it; the high voltage supply and switching can be very greatly miniaturized. Switching times in the region of only a few ns can be attained at tolerable cost. After the threatening light power has disappeared, the electro-optical shutter can be completely opened again after a few tens of ns.
The radiation receiver described in this embodiment and the presented method, with the components listed hereinbelow, should offer a reliable protection of the receiver of a laser rangefinder for peak pulse power irradiated into the receiver pupil of up to 7 megawatts. The protection function is configured as a fully autonomic unit and requires minimal internal electronic circuit cost.
Ideally, the whole optics and electronics, including the warning receiver, can be integrated in a hermetically closed housing of about matchbox size. Only the fiber delay lead would have to be placed externally. The components used in this embodiment are:
Step index optical fiber 17 , about 770 μ core diameter, about 10 m long.
PIN photodiode with comparator for the sensor 11 .
Spliced-on fiber branch 10 to the sensor 11 .
Fiber collimator 23 and fiber coupling-in 39 .
Two through four thin film polarizers 31 .
Two deflecting mirrors 37 .
Two electro-optical crystals 35 or electro-optical substances 33 for the Pockel effect, with about 3 mm diameter.
A fiber 41 connected to a photodetector.
High voltage supply and switch for the electro-optical crystals 35 .
Miniaturized housing for the integration of all the components without the fiber delay lead.
List of Reference Numerals:
1
rangefinder device
3
radiation source/laser
5
radiation receiver
6
radiation inlet/inlet aperture
7
convergent optics
9
beamsplitter
10
fiber branch
11
sensor
13
control
14
evaluation electronics
15
delay device
17
optical fiber
19
shutter
20
electro-optical shutter
21
transformation optics
22
photodetector
23
collimator
31
polarizer
33
optically active substance
35
electro-optical crystal
37
deflecting mirror
39
fiber coupling-in optics
41
photodetector or optical fiber | Radiation receiver with a photodetector and a sensor, wherein the sensor receives the radiation intensity, and a shutter arranged before the photodetector is driven in dependence on the detected incident radiation intensity. The incident radiation is supplied to the photodetector via a delay device arranged before the shutter, so that no radiation destroying the photodetector can reach the photodetector, due to the shutter having been driven, and can if necessary be kept away or absorbed by the shutter. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to optical measurement systems, and more specifically, to an active sensor illumination and detection apparatus for performing sample measurements using associated detector/illuminator groups integrated on one or more substrates.
2. Background of the Invention
One-dimensional and two dimensional measurement and inspection of samples is commonly performed in many industries, including biotechnology, semiconductor, micro electro-mechanical systems (MEMS) and others. For example, in the biotechnology industry, fluorescence measurements are used to determine the response of biological matter to illumination, thus revealing information about the composition and structure of a sample. Typically, for biological fluorescence tests, a sample or a material that is introduced to a sample is “tagged” with a fluorescent compound, the sample is illuminated with a laser, and the resulting fluorescent emissions are mapped to determine the locations of the fluorescent compound after interaction with the sample. For example, a prospective cancer drug may be tagged with a fluorescent compound and introduced to a sample having cancerous tissue. Then the sample is washed to remove excess fluorescent compound. The sample is illuminated and resulting fluorescent emissions are mapped to determine whether or not the prospective drug has bound to the cancer active sensor cells.
The above-described process is typically performed on a bio array, which may be a sample of DNA, gene chips including multiple DNA strands, microtiter plates with wells filled with various biocompounds, or microfluidic lab-on-a-chip devices. In each case, the device or sample is illuminated, typically by a scanning laser or filtered light source. Then, the resulting fluorescence (or lack thereof) is mapped. The mapping is typically performed by either a scanning confocal microscope (SCM) or by imaging onto a charge-coupled-device (CCD) sensor.
The disadvantages of the above-described systems and methods are long scanning times and moving parts for the SCM-based approach and lack of sensitivity and poorer spatial resolution for the CCD-based approach. A third alternative has been implemented, using a scanning laser and a photomultiplier tube for detection, but the cost of the scanning laser and detectors is a disadvantage, as well as the requirement of a moving mechanism.
In another application, in the inspection of color quality in materials, for example dye color, the sample may be illuminated and the sample's optical behavior measured to determine the properties of the sample. Measurement may be made of reflectivity, absorption, transmission, secondary emission or other optical property in order to determine sample characteristics. In order to measure a sufficient field of view, precise control over the color and angular spectrum must be maintained for both illumination and detection systems. The above requirements necessarily add tremendous complexity to any measurement tool.
In the field of MEMS and semiconductor manufacture, repetitive patterns are inspected for defects or anomalies. The device under inspection is illuminated and scattered and/or reflected light is imaged to determine properties of the device under inspection. Such illumination and detection techniques can be quite complex in order to provide the necessary sensitivity and resolution.
Therefore, it is desirable to provide an alternative method and system for providing active illumination and detection for one-dimensional and two-dimensional inspection of samples having low cost, sufficient resolution, high sensitivity and high scanning speed for a broad range of applications.
SUMMARY OF THE INVENTION
The above objectives of providing a method and system for performing active one-dimensional and two-dimensional optical measurements having high speed, high sensitivity and low cost is accomplished in a method and apparatus. The apparatus comprises an active sensor including multiple illumination sources integrated to form a multi-pixel matrix. The matrix may have multiple rows and columns or may include just one row.
Multiple detectors are also integrated within illumination source matrix, each for detecting optical behavior of a sample resulting from the illumination of the sample by one or more of the illumination sources. One detector may be associated with multiple illuminators or one illuminator may be associated with multiple detectors. Filters may be integrated within the illumination and/or detection paths for providing wavelength and/or polarization discrimination capability and lenses may also be integrated within the illumination and/or detection paths providing variable working distances. A lens may be shared between one or more detectors and one or more illumination sources.
The foregoing and other objectives, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiment of the invention, as illustrated in the accompanying drawings, wherein like reference designators indicate like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial diagram depicting an active sensor system including an apparatus in accordance with an embodiment of the present invention.
FIG. 2A is a pictorial diagram depicting details of an active sensor in accordance with an embodiment of the present invention.
FIG. 2B is a pictorial diagram depicting details of an active sensor in accordance with another embodiment of the present invention.
FIG. 2C is a pictorial diagram depicting details of an active sensor in accordance with yet another embodiment of the present invention.
FIG. 2D is a pictorial diagram depicting details of an active sensor in accordance with still another embodiment of the present invention.
FIG. 3 is a pictorial diagram depicting details of an active sensor in accordance another embodiment of the present invention.
FIG. 4 is a pictorial diagram depicting details of an active sensor system in accordance another embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
While the below description is limited, by the way of example, to the measurement of a fluorescent sample, it is understood that the function will be similar for samples such as colored materials, MEMS or semiconductor devices, and/or repetitive patterns, and other applications. In order to avoid repetition, it is understood that the same description will be applicable to other applications that measure optical properties of samples.
Referring now to the figures and in particular to FIG. 1 , a system including an active sensor 10 in accordance with an embodiment of the present invention is shown. Active sensor 10 , which includes a plurality of active sensor active sensor cells 11 , is placed in close proximity with a sample frame 12 , that may contain samples of biological matter tagged with a fluorescent material, or other samples under inspection such as a semiconductor device, for which a standard handling frame may be employed. Active sensor cells 11 each include one or more detectors and one or more illumination elements integrated on the substrate. While the depiction shows a two-dimensional active sensor 10 , active sensor 10 may also be a one-dimensional active sensor, comprising only one row of active sensor cells 11 .
The detection elements within active sensor cells 11 are coupled to a processing subsystem for detecting light scattered or emitted from associated portions of the samples. The association is by virtue of the proximity of the active sensor cells 11 to the sample frame 12 so that the fields of the detectors generally do not substantially overlap, or so that any overlap is generally limited to adjacent pixels. Similarly, the illumination element fields also do not substantially overlap in general and can be used to selectively illuminate portions of the samples. Sample frame 12 may comprise a plurality of wells, as in a microtiter plate or other multi-sample/multi-cell device, in which case, the spacing and location of active sensor cells 11 can be dictated by the spacing and location of wells in sample frame 12 . One cell 11 may correspond to a single well, giving active sensor 10 the ability to simultaneously process optical information at each cell without requiring a scanning mechanism.
Alternatively, sample frame 12 may comprise a single contiguous sample, such as a tissue sample or single sample having multiple discrete portions such as a DNA gel. Where discrete boundaries are not present, it may be desirable to sequentially illuminate the illumination elements individually, or program an illumination pattern such that adjacent illumination elements do not cause illumination of portions of a sample associated with other illumination elements. Illumination control subsystem 16 provides for control of illumination elements within active sensor cells 11 and is coupled to a processing subsystem 14 that receives the outputs of detectors within active sensor cells 11 . The interconnection of illumination control subsystem 16 with processing subsystem 14 permits synchronization of illumination and detection permitting accurate determination of response time and correlation of detected fluorescent emissions to the activation of an illumination element within a cell 11 . In addition, illumination elements can be pulsed or modulated and detection elements can be shuttered or time-gated to allow complex temporally resolved measurement schemes.
In other embodiments of the present invention, sample frame 12 may hold samples comprising a matrix of colored elements or samples may have a scattering pattern such as found on MEMS or semiconductor devices. The function of the system is identical to that described previously except that the detected light is no longer fluorescent emission, but scattered light.
The illumination elements included within active sensor cells 11 are substrate-integrated sources that may be provided by TFT-LCD devices, diode emitters, organic LEDs (OLEDs), vertical cavity emitting lasers (VCELs) or other light sources that may be integrated to form a high-density illumination matrix. The detectors included within active sensor cells 11 may be PIN photo-diodes, CCD sensors, CMOS sensors or other detectors that are suitable for integration within the illumination matrix. Lenses are optionally included for coupling a cell or field of active sensor cells 11 to samples or portions thereof and may be implemented using standard microlenses, graded-refractive-index (GRIN) lenses, fiber couplers or other suitable focusing/coupling or imaging mechanism.
Referring now to FIG. 2A , details of an active sensor 10 A including active sensor cells 11 A, in accordance with an embodiment of the present invention are shown. FIG. 2A also shows an exemplary sample frame 12 A including sample elements 20 (depicted as wells in a microtiter plate) that are associated with particular active sensor cells 11 A via proximity of sample frame 12 A to active sensor 10 A. A substrate 28 A supports active sensor cells 11 A and a cover glass 22 is optionally included to protect active sensor cells 11 A and may be spaced above active sensor cells 11 A as shown, or placed in contact with active sensor cells 11 A.
The structure of active sensor cells 11 A is shown in balloon 23 A. A single illumination element 24 A is paired (associated) with a single detector 27 A for detecting fluorescence of biological matter deposited in an associated sample element 20 A due to illumination from illumination element 24 A (or other optical characteristics in non-fluorescence measurements). A microlens 25 A is optionally integrated over illumination element 24 A and detector 27 A for focusing or imaging a field of illumination element 24 A and detector 27 A on or within sample element 20 A. A filter 26 A is integrated between detector 27 A and microlens 25 A for providing a passband response around a specific optical wavelength and/or a polarization characteristic, providing wavelength and/or polarization selectivity in the output response of detector 27 A, whereby a specific fluorescence band is detected by detector 27 A. Illumination element 24 A is generally a narrowband emitter in the present configuration, but in some applications may be a broadband source, depending on whether or not the measurement being made is dependent on a specific excitation wavelength. The embodiment depicted in FIG. 2A , is exemplary of a single-detector, single-illumination element pairing that is associated with a unique portion of a sample or unique samples of a sample frame by virtue of the sample proximity. Other configurations depicted in other embodiments below or otherwise understood to be encompassed by the present invention include other groupings of multiple or single detectors to multiple or single illumination elements or arrangements including a multi-pixel illumination element array interspersed with a multi-pixel detector array where no specific grouping of detectors and illumination elements is employed. Similarly, it is understood that various geometric arrangements of the illumination/detector pair can be used, including side-by-side, concentric arrangements, quad detectors and others and that an imaging system may be used so that the array or arrays do not have to be placed in close proximity to the samples.
Referring now to FIG. 2B , details of an active sensor 10 B including active sensor cells 11 B, in accordance with another embodiment of the present invention are shown. FIG. 2B also shows an exemplary sample frame 12 A including sample elements 20 that are associated with particular active sensor cells 11 B via proximity of sample frame 12 A to active sensor 10 B. A substrate 28 B supports active sensor cells 11 B and cover glass 22 is optionally included to protect active sensor cells 11 B and may be spaced above active sensor cells 11 B as shown, or placed in contact with active sensor cells 11 B.
The structure of active sensor cells 11 B is shown in balloon 23 B. A single illumination element 24 B is paired (associated) with a single detector 27 B for detecting fluorescence of biological matter deposited in an associated cell forming sample element 20 A due to illumination from illumination element 24 B (or measuring other optical characteristics in non-fluorescence measurements). A microlens 25 B is optionally integrated over illumination over illumination element 24 B and detector 27 B for focusing or imaging a field of illumination element 24 B and detector 27 B on or within well 20 A. A filter 29 B is integrated between illumination element 24 B and microlens 25 B for providing a passband response around a specific optical wavelength and/or polarization characteristic, providing a narrowband and/or polarization-controlled illumination source. Illumination element 24 B is generally a broadband emitter in the present configuration.
Another filter 26 B is integrated between detector 27 B and microlens 25 B for providing a passband response around a specific optical wavelength and/or a polarization characteristic, providing wavelength and/or polarization selectivity in the output response of detector 27 B, whereby a specific fluorescence band is detected by detector 27 B. Filters 26 B and 29 B are not constrained to have the same passband wavelength, as the fluorescent response of a material may differ greatly from the specific excitation wavelength used to excite the biological sample. The embodiment of cell 11 B depicted in FIG. 2B is another example of a single-detector single-illumination element pairing. Other possible combinations include a filtered illumination source with an unfiltered detector, polarized illumination source with filtered detector and other combinations of passband and/or polarizer filters.
Referring now to FIG. 2C , details of an active sensor 10 C including active sensor cells 11 C, in accordance with yet another embodiment of the present invention are shown. FIG. 2C also shows an exemplary sample frame 12 A including sample elements (wells) 20 that are associated with particular active sensor cells 11 C via proximity of sample frame 12 A to active sensor 10 C. A substrate 28 C supports active sensor cells 11 C and cover glass 22 is optionally included to protect active sensor cells 11 C and may be spaced above active sensor cells 11 C as shown, or placed in contact with active sensor cells 11 C.
The structure of active sensor cells 11 C is shown in balloon 23 C. Multiple illumination elements 24 C are paired (associated) with a single detector 27 C for detecting fluorescence of biological matter deposited in an associated sample element 20 A due to illumination from illumination elements 24 C (or other optical characteristics in non-fluorescence measurements). A microlens 25 C is optionally integrated over illumination over illumination elements 24 C and detector 27 C for focusing or imaging a field of illumination elements 24 C and detector 27 C on or within well 20 A. A filter 26 C is integrated between detector 27 C and microlens 25 C for providing passband response around a specific optical wavelength and/or a polarization characteristic, providing wavelength and/or polarization selectivity in the output response. Illumination elements 24 C are generally narrowband emitters having separate predetermined illumination wavelengths in the present configuration and are generally controlled by illumination control subsystem 16 so that fluorescent response of samples or portions thereof to multiple predetermined wavelength excitation can be determined by enabling first one set of illumination elements in active sensor cells 11 C corresponding to a first wavelength and then a second set of illumination elements in active sensor cells 11 C corresponding to a second wavelength and observing the response using detectors 27 C. The embodiment depicted in FIG. 2C is an example of multiple-illumination element, single-detector grouping. The number of associated illumination elements to a single detector also may be greater than two.
Referring now to FIG. 2D , details of an active sensor 10 D including active sensor cells 11 D, in accordance with still another embodiment of the present invention are shown. FIG. 2D also shows an exemplary sample frame 12 A including sample elements (wells) 20 that are associated with particular active sensor cells 11 D via proximity of sample frame 12 A to active sensor 10 D. A substrate 28 D supports active sensor cells 11 D and cover glass 22 is optionally included to protect active sensor cells 11 D and may be spaced above active sensor cells 11 D as shown, or placed in contact with active sensor cells 11 D.
The structure of active sensor cells 11 D is shown in balloon 23 D. Multiple detectors 27 D are paired (associated) with a single illumination element 24 D for detecting fluorescence of biological matter deposited in an associated sample element 20 A due to illumination from illumination element 24 D (or other optical characteristics in non-fluorescence measurements). A microlens 25 D is optionally integrated over illumination element 24 D and detectors 27 D for focusing or imaging a field of illumination element 24 D and detectors 27 D on or within well 20 A. Multiple filters 29 D are integrated between detectors 27 D and microlens 25 D for providing a unique passband response around a specific optical wavelength for each detector 27 D in a cell 11 D, providing multiple narrowband detector responses. Alternatively or in combination, filters 29 D may provide multiple polarization responses, providing the ability to determine polarization ratios, and so forth. Illumination element 24 D is generally a narrowband emitter for exciting a sample or portions thereof and detectors 27 D in conjunction with filters 29 D provide separate responses to the illumination, whereby multiple fluorescence band emissions can be simultaneously detected in response to narrowband excitation. The embodiment depicted in FIG. 2D is an example of single-illumination element, multiple-detector grouping. The number of associated detectors to a single illumination element also may be greater than two.
Referring now to FIG. 3 , details of an active sensor system in accordance with an embodiment of the present invention are shown. Two separate array devices are employed, device 10 E is a detection array that includes elements as depicted in balloon 23 E, including detectors 27 E filters 26 E and microlens 25 E. Device 10 F is an illumination array including illumination elements 24 F and microlenses 25 F as depicted in balloon 23 F. However, the elements may be variations on the depicted structure in accordance with the above-described element types and either or both arrays may include both illumination and detection elements. For example to provide a transmission and reflection/scattering measurement, device 10 F may also include detection elements for detecting back-scattered light associated with each illumination element and/or sample element 20 E.
The system of FIG. 3 is particularly suited for transmission measurements as detector device 10 E is on the opposite side of samples 20 E from illumination device 10 F. Groups associating detectors 27 E and illumination elements 24 F in the system of FIG. 3 are associated by the location the fields of light transmitted by particular illumination elements 24 F and received by particular detectors 27 E, rather than also being associated by proximity as in the other exemplary embodiments described above, and as such, comprise the active sensor “cells” in the present embodiment. Both device 10 E and device 10 F are fabricated on substrates ( 28 E and 28 F respectively) and may include cover glasses ( 22 E and 22 F respectively). It should be noted in all of the above examples, filtering may be provided by a “gel” or colored cover glass that is provided in addition to or in place of the illustrated cover glasses for providing a wavelength/or polarization filtered optical characteristic within the system.
Referring now to FIG. 4 , an active sensor system in accordance with yet another embodiment of the present invention is depicted. Active sensor 10 G, which may be any of the active sensors described above or variations thereon, is coupled by an imaging lens 41 to sample elements 20 G. The imaging system may alternatively be or include optical fibers, waveguides of other type or any known method for “remoting” (or “relaying”) an image from sample elements 20 G to active sensor 10 G. As long as a grouping via the image is made between illumination elements and detection elements within active sensor 10 G, detection of individual sample element 20 G behavior is provided. Optical paths (such as optical paths 42 and 43 ) associate co-located detection and illumination elements within active sensor 10 G with a particular sample element (e.g., optical path 42 associates a particular detector/illuminator with sample element 20 G). Alternatively, separate detection and illumination devices may be provided and coupled via beam-splitters, couplers or physical arrangement (angular orientation, etc.), so that an association between one or more detection elements and one or more illumination elements is preserved. While the embodiment shown uses a single lens 41 to relay light between active sensor 10 G element groups and sample elements with an inverted position relationship, other lens/relaying-device configurations may be employed including position-rectified configurations.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form, and details may be made therein without departing from the spirit and scope of the invention. | An active sensor a method for optical illumination and detection provides low cost and high-speed optical scanning of bio-arrays, DNA samples/chips, semiconductors, micro-electromechanical systems and other samples requiring inspection or measurement. A plurality of illumination sources forming a parallel multi-pixel array is used to illuminate one or more samples via an imaging system or by placement in close proximity to the samples. The array may be a line array or a two-dimensional array. A plurality of detectors is integrated within the multi-pixel illumination array or provided in a separate array, each detector for detecting optical properties of the sample that results from illumination by one or more associated illumination sources. One detector may be associated with multiple illuminators or one illuminator may be associated with multiple detectors. Filters may be integrated within the illumination path and/or detection paths to provide wavelength and/or polarization discrimination capability and microlenses may also be incorporated within the illumination path and/or detection paths to provide focusing or imaging. The illumination sources may be provided by TFT-LCD devices, diode emitters, organic LEDs (OLEDs), vertical cavity emitting lasers (VCELs) or other light sources that may be integrated to form a high-density illumination matrix. The detectors may be PIN photo-diodes or other suitable detectors that are capable of integration within the illumination matrix. | 6 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine.
[0002] JP-A-2008-175098 discloses fuel control means capable of maintaining flame stability before and after the starting of humidification while ensuring a low NOx performance of a combustor in a humid air gas turbine power plant, which achieves an improvement in output and efficiency through adding moisture to a gas turbine working fluid (air) to humidify the same and using the humidified air to recover heat energy stored in gas turbine exhaust gases.
[0003] Generally, when the number of revolution rises at the startup of a gas turbine, an operating state tends to become unstable due to disturbance as compared with that after a rated number of revolution is reached, since a compressor intake air flow rate and the vibration characteristic of a rotating body vary.
[0004] In humid air gas turbine power plants, since disturbance is caused on a gas turbine when humidification is started in the course of an increase in number of revolution, it is desirable to start humidification in a partially loaded state after a rated number of revolution is reached, in order to ensure stability at the startup.
[0005] A major part of NOx generated in a combustor comprises thermal NOx generated by oxidation of nitrogen contained in air when fuel, such as natural gas, kerosene, light oil, or the like, having a small nitrogen content is used.
[0006] Since generation of thermal NOx is high in temperature dependency, the basic idea of a low NOx combustion method in gas turbines, in which such fuel is used, resides generally in a decrease in flame temperature. Premixed combustion, in which fuel and air are beforehand mixed and then burned, is known as a measure for a decrease in flame temperature.
[0007] Also, in the case where combustion air is made high in temperature by a regenerator as in a humid air gas turbine plant, it is necessary to attain low NOx through appropriately controlling flame temperature while preventing self-ignition of fuel, and a method, shown in JP-A-2008-175098, of jetting fuel and air as a multiplicity of coaxial jet streams of small diameter into a combustion chamber is effective.
[0008] In order to make a low NOx performance and flame compatible with each other in such low NOx combustor, it is essential to regulate a fuel-air ratio, which is a ratio of fuel flow rate and air flow rate, in a predetermined range.
[0009] JP-A-7-189743 discloses means of regulating a ratio of fuel flow rate and air flow rate aiming at a change in opening degree of a compressor inlet guide valve, which accompanies operation of a gas turbine, a change in atmospheric temperature, a change in air flow rate, which is attributable to a change in atmospheric pressure, and a change in fuel flow rate, which is attributable to fuel temperature and a change in fuel heating value.
[0010] JP-A-11-72029 discloses means of achieving an increase and a decrease in fuel flow rate in accordance with humidity of atmospheric intake air and intake spraying water quantity, in a gas turbine system, in which intake air of a compressor is cooled by intake spraying for reduction in compressive power.
[0011] When humidification is started in a humid air gas turbine power plant, combustion air in a combustor is increased in humidity, so that heat of combustion is deprived of to lead to a decrease in flame temperature and a NOx yield is reduced.
[0012] Also, since addition of moisture causes a turbine working fluid to increase in flow rate, fuel flow rate is decreased in order to maintain the number of revolution constant. Reduction in fuel flow rate leads to a decrease in flame temperature, so that a NOx yield decreases. Further, since a decrease in flame temperature leads to reduction in recovered heating value in a regenerator, combustion air temperature drops. A decrease in combustion air temperature causes flame temperature to be decreased to lead to reduction in NOx yield.
[0013] Humidification is started in this manner whereby (1) an increase in moisture, (2) reduction in fuel flow rate, and (3) a decrease in air temperature advance at the same time to lead to a decrease in flame temperature, so that a NOx yield decreases but combustion stability is degraded.
[0014] Setting combustion air flow rate low taking previous account of humidification enables eliminating occurrence of flame blow-off under a high humid condition. However, in a combustor with combustor air distribution thus set, flame temperature rises conversely to the matter described above before the starting of humidification, so that flame stability is ensured but a NOx yield tends to increase.
[0015] That is, in a humid air gas turbine plant, before and after the starting of humidification, NOx generation and flame stability in a combustor suffer a large change in condition. Also, it is thought that at the time of an increase in gas turbine load, lag is caused by valve control and a volume of an associated system until moisture is actually added to combustion air after the starting of humidification.
[0016] It is thought that at the time of a decrease in gas turbine load, lag is caused due to the same reason until combustion air is decreased in humidity.
[0017] When in starting the humidifying operation and stopping the operation, combustion air humidity is varied after a lag time, flame temperature possibly rises or drops excessively, so that there is a possibility of a remarkable increase in NOx and a decrease in combustion stability.
[0018] Accordingly, there is a demand for control means for stable combustion of a combustor in low NOx under such change in condition.
[0019] Hereupon, as disclosed in JP-A-2008-175098, combustion stability after humidification can be ensured with the use of means for setting a ratio of fuel supplied to a combustion section of an excellent flame holding performance to control fuel so that a part of combustion sections of a combustor provided with a plurality of combustion sections supplied individually with fuel comprises combustion section or sections (provided with air holes, which impart swirl components to air flow), which are more excellent in flame holding performance than the remaining combustion sections and for a predetermined period of time after the starting of humidification, combustion temperature in the combustion section or sections having an excellent flame holding performance is made equal to or higher than combustion temperature before the starting of humidification.
[0020] In the case where in accommodating such change in humidity, the means as disclosed in JP-A-7-189743 is applied to ensure stability in combustion, it is thought to measure moisture in combustion air to control a ratio of fuel flow rate on the basis of the value thereof.
[0021] Hereupon, it is thought to measure moisture in combustion air with the use of a humidity sensor.
[0022] In view of a humidity measuring position, humidity measurement at an outlet of a humidifier is first taken into consideration. Since air at an outlet of a humidifier is close to the dew point, however, there is caused a problem that accuracy of measurement cannot be expected in measurement with a humidity sensor. Secondly, humidity measurement at an outlet of a regenerator is taken into consideration. Since air at an outlet of a regenerator is as high as 450° C. or above, however, high heat resistance is required of a humidity sensor.
[0023] Subsequently, a performance demanded of a humidity sensor is taken into consideration. Due to a change in humidity contained in air, a combustion state varies every moment. Therefore, it is demanded of a humidity sensor to measure humidity in air with high responsibility to control a ratio of fuel flow rate to maintain stable combustion.
[0024] Thus, there are caused many problems in measuring humidity in air with the use of a humidity sensor to exercise combustion control to achieve stable combustion.
[0025] JP-A-11-72029 discloses means of achieving stable combustion accommodating that change in combustion air humidity, which is caused by a change in atmospheric humidity and intake spraying water quantity, in a gas turbine system, in which intake air of a compressor is cooled by an intake spraying device for reduction in compressive power.
[0026] Since the humid air gas turbines disclosed in the prior art comprise a humidifier positioned downstream of a compressor, a large change in combustion air humidity is caused by not only intake spraying with the compressor but also humidification with the humidifier. Also, when compressor discharge air is varied in temperature and humidity depending upon the operating condition of an intake spraying device, it is thought that the humidifier is varied in humidification in accordance therewith.
[0027] However, no examination has been made for the technology of controlling a fuel flow rate of a gas turbine combustor taking account of both a change in humidity in a compressor due to intake spraying and a change in humidity in a humidifier in order to cause stable combustion in the gas turbine combustor of a humid air gas turbine.
[0028] Also, no examination has been made for the technology of controlling a fuel flow rate of a humid air gas turbine combustor to be capable of operation in high reliability before humidification, before and after the starting of humidification, and during humidification in a humid air gas turbine without damage in combustion stability of a gas turbine combustor and of maintaining a NOx yield in low level irrespective of a humidified condition.
BRIEF SUMMARY OF THE INVENTION
[0029] It is an object of the invention to provide a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine, which are capable of operation in high reliability before humidification, before and after the starting of humidification, and during humidification without damage in combustion stability and of maintaining a NOx yield in low level irrespective of a humidified condition, in a humid air gas turbine for humidification of air with the use of a spray type humidifier.
[0030] According to the invention, there is provided a fuel flow control method of a gas turbine combustor provided in a humid air gas turbine comprising a compressor, the gas turbine combustor, in which a fuel is burned with the use of a compressed air compressed by the compressor to generate a combustion gas, a turbine driven by a combustion gas generated in the gas turbine combustor, and a humidifier for humidifying a compressed air compressed by the compressor and supplied to the gas turbine combustor with a spray water, the gas turbine combustor comprising a plurality of combustion sections comprised of a plurality of fuel nozzles for supplying of a fuel and a plurality of air flow passages for supplying of a combustion air, in which method fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor are controlled on the basis of deviation between a load command and electric power generation, a part of the plurality of combustion sections provided in the gas turbine combustor being formed into a combustion section or sections, which are more excellent in flame holding performance than the remaining combustion sections, in which method a fuel flow rate supplied to the combustion sections of the gas turbine combustor is controlled by evaluating a moisture content of a combustion air supplied to the gas turbine combustor from the humidifier on the basis of a humidification water quantity supplied to a compression air in the humidifier and an air temperature after humidification, and regulating a fuel ratio of a fuel flow rate supplied to the combustion section or sections of excellent flame holding performance formed in the gas turbine combustor and a fuel flow rate supplied to the remaining combustion sections on the basis of the evaluation of moisture content in the combustion air.
[0031] Also, according to the invention, there is provided a fuel flow control method of a gas turbine combustor provided in a humid air gas turbine comprising a compressor, an intake spraying device for spraying water on an intake air in an intake section of the compressor, a combustor, in which a fuel is burned with the use of a compressed air compressed by the compressor, a turbine driven by a combustion gas from the combustor, and a spray type humidifier for humidifying a compressed air compressed by the compressor with a spray water, the gas turbine combustor comprising a plurality of combustion sections comprised of a plurality of fuel nozzles for supplying of a fuel and a plurality of air flow passages for supplying of a combustion air, in which method fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor are controlled on the basis of deviation between a load command and electric power generation, a part of the plurality of combustion sections provided in the gas turbine combustor being formed into a combustion section or sections, which are more excellent in flame holding performance than the remaining combustion sections, in which method a fuel flow rate supplied to the combustion sections of the gas turbine combustor is controlled by evaluating a moisture content of a combustion air supplied to the gas turbine combustor from the humidifier on the basis of a humidification water quantity in the intake spraying device, a humidification water quantity supplied to a compression air, and an air temperature after humidification with the humidifier, and regulating a fuel ratio of a fuel flow rate supplied to the combustion section or sections of excellent flame holding performance formed in the gas turbine combustor and a fuel flow rate supplied to the remaining combustion sections on the basis of the evaluation of moisture content in the combustion air.
[0032] According to the invention, there is provided a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine comprising a compressor, the gas turbine combustor, in which a fuel is burned with the use of a compressed air compressed by the compressor to generate a combustion gas, a turbine driven by a combustion gas generated in the gas turbine combustor, and a humidifier for humidifying a combustion air compressed by the compressor and supplied to the gas turbine combustor, the gas turbine combustor comprising a plurality of combustion sections comprised of a plurality of fuel nozzles for supplying of a fuel and a plurality of air flow passages for supplying of a combustion air, in which system fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor are controlled on the basis of deviation between a load command and electric power generation, a part of the plurality of combustion sections provided in the gas turbine combustor being formed into a combustion section or sections, which are more excellent in flame holding performance than the remaining combustion sections, the fuel flow control system, which controls a flow rate of a fuel supplied to the plurality of combustion sections of the gas turbine combustor, comprising a fuel flow control unit for outputting a fuel flow command to control a fuel supplied to the plurality of combustion sections of the gas turbine combustor on the basis of deviation between a load command MWD and an actual electric power generation MW, a fuel flow rate ratio setter for setting fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of a fuel flow command output from the fuel flow control unit, and an actual fuel flow control unit for actuating fuel control valves, which regulate flow rate ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of fuel flow rate ratio set values set by the fuel flow rate ratio setter, and further comprising a humidifier outlet maximum humidity computing unit for calculating a maximum humidity at an outlet of the humidifier from an outlet air temperature in the humidifier, a humidifier outlet humidity computing unit for calculating a humidifier outlet humidity from a spray water quantity of the humidifier and a humidifier outlet maximum humidity calculated by the humidifier outlet maximum humidity computing unit, a combustion temperature F1 gain computing unit and a humidity F1 gain computing unit for calculating control gains, respectively, for combustion temperature and humidity with respect to a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance in the gas turbine combustor from a combustion air flow rate of a combustion air supplied to the gas turbine combustor and a humidifier outlet humidity calculated by the humidifier outlet humidity computing unit, and in which system a flow rate ratio of a fuel supplied to the plurality of combustion sections of the gas turbine combustor is controlled by using the fuel flow rate ratio setter to set a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance out of the plurality of combustion sections provided in the gas turbine combustor on the basis of computed values of the combustion temperature F1 gain computing unit and the humidity F1 gain computing unit.
[0033] Also, according to the invention, there is provided a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine comprising a compressor, the gas turbine combustor, in which a fuel is burned with the use of a compressed air compressed by the compressor to generate a combustion gas, a turbine driven by a combustion gas generated in the gas turbine combustor, and a humidifier for humidifying a combustion air compressed by the compressor and supplied to the gas turbine combustor, the gas turbine combustor comprising a plurality of combustion sections comprised of a plurality of fuel nozzles for supplying of a fuel and a plurality of air flow passages for supplying of a combustion air, in which system fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor are controlled on the basis of deviation between a load command and electric power generation, a part of the plurality of combustion sections provided in the gas turbine combustor being formed into a combustion section or sections, which are more excellent in flame holding performance than the remaining combustion sections, the fuel flow control system, which controls a flow rate of a fuel supplied to the plurality of combustion sections of the gas turbine combustor, comprising a fuel flow control unit for outputting a fuel flow command to control a fuel supplied to the plurality of combustion sections of the gas turbine combustor on the basis of deviation between a load command MWD and an actual electric power generation MW, a fuel flow rate ratio setter for setting fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of a fuel flow command output from the fuel flow control unit, and an actual fuel flow control unit for actuating fuel control valves, which regulate flow rate ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of fuel flow rate ratio set values set by the fuel flow rate ratio setter, and further comprising a humidifier outlet maximum vapor quantity computing unit for calculating a maximum vapor quantity at an outlet of the humidifier from an outlet air temperature in the humidifier, a humidifier outlet vapor quantity computing unit for calculating a humidifier outlet vapor quantity from a spray water quantity in the humidifier and a humidifier outlet maximum vapor quantity calculated by the humidifier outlet maximum vapor quantity computing unit, a humidifier outlet humidity computing unit for calculating a humidifier outlet humidity from a humidifier outlet vapor quantity calculated by the humidifier outlet vapor quantity computing unit, a combustion temperature F1 gain computing unit and a humidity F1 gain computing unit for calculating control gains, respectively, for combustion temperature and humidity with respect to a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance in the gas turbine combustor from a combustion air flow rate of a combustion air supplied to the gas turbine combustor and a humidifier outlet humidity calculated by the humidifier outlet humidity computing unit, and in which system a flow rate ratio of a fuel supplied to the plurality of combustion sections of the gas turbine combustor is controlled by using the fuel flow rate ratio setter to set a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance out of the plurality of combustion sections provided in the gas turbine combustor on the basis of computed values of the combustion temperature F1 gain computing unit and the humidity F1 gain computing unit.
[0034] Also, according to the invention, there is provided a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine comprising a compressor, an intake spraying device, which sprays water onto an intake air at an intake part of the compressor, the gas turbine combustor, in which a fuel is burned with the use of a compressed air compressed by the compressor to generate a combustion gas, a turbine driven by a combustion gas generated in the gas turbine combustor, and a humidifier for humidifying a combustion air compressed by the compressor and supplied to the gas turbine combustor, the gas turbine combustor comprising a plurality of combustion sections comprised of a plurality of fuel nozzles for supplying of a fuel and a plurality of air flow passages for supplying of a combustion air, in which system fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor are controlled on the basis of deviation between a load command and electric power generation, a part of the plurality of combustion sections provided in the gas turbine combustor being formed into a combustion section or sections, which are more excellent in flame holding performance than the remaining combustion sections, the fuel flow control system, which controls a flow rate of a fuel supplied to the plurality of combustion sections of the gas turbine combustor, comprising a fuel flow control unit for outputting a fuel flow command to control a fuel supplied to the plurality of combustion sections of the gas turbine combustor on the basis of deviation between a load command MWD and an actual electric power generation MW, a fuel flow rate ratio setter for setting fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of a fuel flow command output from the fuel flow control unit, and an actual fuel flow control unit for actuating fuel control valves, which regulate flow rate ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of fuel flow rate ratio set values set by the fuel flow rate ratio setter, and further comprising a humidifier outlet maximum humidity computing unit for calculating a maximum humidity at an outlet of the humidifier from an outlet air temperature in the humidifier, a humidifier outlet humidity computing unit for calculating a humidifier outlet humidity from a spray water quantity of the humidifier, a spray water quantity of the intake spraying device, and a humidifier outlet maximum humidity calculated by the humidifier outlet maximum humidity computing unit, a combustion temperature F1 gain computing unit and a humidity F1 gain computing unit for calculating control gains, respectively, for combustion temperature and humidity with respect to a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance in the gas turbine combustor from a combustion air flow rate of a combustion air supplied to the gas turbine combustor and a humidifier outlet humidity calculated by the humidifier outlet humidity computing unit, and in which system a flow rate ratio of a fuel supplied to the plurality of combustion sections of the gas turbine combustor is controlled by using the fuel flow rate ratio setter to set a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance out of the plurality of combustion sections provided in the gas turbine combustor on the basis of computed values of the combustion temperature F1 gain computing unit and the humidity F1 gain computing unit.
[0035] Also, according to the invention, there is provided a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine comprising a compressor, an intake spraying device, which sprays water onto an intake air at an intake part of the compressor, the gas turbine combustor, in which a fuel is burned with the use of a compressed air compressed by the compressor to generate a combustion gas, a turbine driven, by a combustion gas generated in the gas turbine combustor, and a humidifier for humidifying a combustion air compressed by the compressor and supplied to the gas turbine combustor, the gas turbine combustor comprising a plurality of combustion sections comprised of a plurality of fuel nozzles for supplying of a fuel and a plurality of air flow passages for supplying of a combustion air, in which system fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor are controlled on the basis of deviation between a load command and electric power generation, a part of the plurality of combustion sections provided in the gas turbine combustor being formed into a combustion section or sections, which are more excellent in flame holding performance than the remaining combustion sections, the fuel flow control system, which controls a flow rate of a fuel supplied to the plurality of combustion sections of the gas turbine combustor, comprising a fuel flow control unit for outputting a fuel flow command to control a fuel supplied to the plurality of combustion sections of the gas turbine combustor on the basis of deviation between a load command MWD and an actual electric power generation MW, a fuel flow rate ratio setter for setting fuel ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of a fuel flow command output from the fuel flow control unit, and an actual fuel flow control unit for actuating fuel control valves, which regulate flow rate ratios of fuels, respectively, supplied to the plurality of combustion sections of the gas turbine combustor on the basis of fuel flow rate ratio set values set by the fuel flow rate ratio setter, and further comprising a humidifier outlet maximum vapor quantity computing unit for calculating a maximum vapor quantity at an outlet of the humidifier from an outlet air temperature in the humidifier, a humidifier spraying quantity corrected quantity computing unit for calculating a corrected quantity of a humidifier spraying quantity from a spray water quantity of the intake spray device, a humidifier outlet vapor quantity computing unit for calculating a humidifier outlet vapor quantity from a spray water quantity in the humidifier, a humidifier outlet maximum vapor quantity calculated by the humidifier outlet maximum vapor quantity computing unit, and a humidifier spraying quantity corrected quantity calculated by the humidifier spraying quantity corrected quantity computing unit, a humidifier outlet humidity computing unit for calculating a humidifier outlet humidity from a humidifier outlet vapor quantity calculated by the humidifier outlet vapor quantity computing unit, a combustion temperature F1 gain computing unit and a humidity F1 gain computing unit for calculating control gains, respectively, for combustion temperature and humidity with respect to a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance in the gas turbine combustor from a combustion air flow rate of a combustion air supplied to the gas turbine combustor and a humidifier outlet humidity calculated by the humidifier outlet humidity computing unit, and in which system a flow rate ratio of a fuel supplied to the plurality of combustion sections of the gas turbine combustor is controlled by using the fuel flow rate ratio setter to set a fuel ratio of a fuel supplied to the combustion section or sections of excellent flame holding performance out of the plurality of combustion sections provided in the gas turbine combustor on the basis of computed values of the combustion temperature F1 gain computing unit and the humidity F1 gain computing unit.
[0036] According to the invention, it is possible to realize a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine, which are capable of operation in high reliability before humidification, before and after the starting of humidification, and during humidification without damage in combustion stability and of maintaining a NOx yield in low level irrespective of a humidified condition, in a humid air gas turbine for humidification of air with the use of a spray type humidifier.
[0037] Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIES OF THE DRAWINGS
[0038] FIG. 1 is a configuration showing a humid air gas turbine system provided with a gas turbine combustor according to a first embodiment of the invention.
[0039] FIG. 2 is a partially sectional view showing the construction of fuel nozzles provided in the gas turbine combustor, according to the first embodiment of the invention, shown in FIG. 1 .
[0040] FIG. 3 is a front view showing an air hole plate provided in the gas turbine combustor, shown in FIG. 2 , of the first embodiment of the invention with fuel nozzles as viewed from a downstream side of a combustion chamber.
[0041] FIG. 4 is a characteristics graph representing an example of the operating method of the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention.
[0042] FIG. 5 is a characteristics graph representing another example of the operating method of the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention.
[0043] FIG. 6 is a schematic diagram showing the relationship between humidifier spray water quantity and humidifier outlet humidity in the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention.
[0044] FIG. 7 is a schematic diagram (approximate diagram) showing the relationship between humidifier spray water quantity and humidifier outlet humidity in the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention.
[0045] FIG. 8 is a characteristics graph representing a further example of the operating method of the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention.
[0046] FIG. 9 is a control block diagram showing an example of a control unit constituting a combustion control system of the gas turbine combustor of the first embodiment of the invention provided in a humid air gas turbine.
[0047] FIG. 10 is a view illustrating the configuration of F1 gain of F1 burners in the combustion control system of the gas turbine combustor, shown in FIG. 9 , of the first embodiment of the invention.
[0048] FIG. 11 is a characteristics graph representing an example of the operating method of a humid air gas turbine system provided with a gas turbine combustor according to a second embodiment of the invention.
[0049] FIG. 12 is a schematic diagram showing the relationship between humidifier spray water quantity and humidifier outlet humidity in the humid air gas turbine system provided with the gas turbine combustor of the second embodiment of the invention.
[0050] FIG. 13 is a control block diagram showing an example of a control unit constituting a combustion control system of the gas turbine combustor, according to the second embodiment of the invention, provided in a humid air gas turbine.
[0051] FIG. 14 is a configuration showing a humid air gas turbine system provided with a gas turbine combustor according to a third embodiment of the invention.
[0052] FIG. 15 is a characteristics graph representing an example of the operating method of the humid air gas turbine system provided with the gas turbine combustor according to the third embodiment of the invention.
[0053] FIG. 16 is a characteristics graph representing another example of the operating method of the humid air gas turbine system provided with the gas turbine combustor according to the third embodiment of the invention.
[0054] FIG. 17 is a schematic diagram showing the relationship between humidifier spray water quantity and humidifier outlet humidity in the humid air gas turbine system provided with the gas turbine combustor according to the third embodiment of the invention.
[0055] FIG. 18 is a control block diagram showing an example of a control unit constituting a combustion control system of the gas turbine combustor, according to the third embodiment of the invention, provided in a humid air gas turbine system.
[0056] FIG. 19 is a characteristics graph representing an example of the operating method of a humid air gas turbine system provided with a gas turbine combustor according to a fourth embodiment of the invention.
[0057] FIG. 20 is a schematic diagram showing the relationship between humidifier spray water quantity and humidifier outlet humidity in the humid air gas turbine system provided with the gas turbine combustor according to the fourth embodiment of the invention.
[0058] FIG. 21 is a control block diagram showing an example of a control unit constituting a combustion control system of the gas turbine combustor, according to the fourth embodiment of the invention, provided in a humid air gas turbine.
DETAILED DESCRIPTION OF THE INVENTION
[0059] A fuel flow control method and a fuel flow control system of a humid air gas turbine combustor according to embodiments of the invention will be described below with reference to the drawings.
Embodiment 1
[0060] A fuel flow control method and a fuel flow control system of a gas turbine combustor, according to a first embodiment of the invention, provided in a humid air gas turbine will be described with FIGS. 1 to 10 .
[0061] FIG. 1 is a system flow diagram showing the whole configuration of a humid air gas turbine system, to which the fuel flow control method and the fuel flow control system of the gas turbine combustor, according to the first embodiment of the invention, provided in the humid air gas turbine are applied.
[0062] In the humid air gas turbine system shown in FIG. 1 , a humid air gas turbine for power generation comprises a compressor 1 , a gas turbine combustor 2 , a turbine 3 , a humidifier 4 , and a regenerator 5 , and a generator 20 is rotated by output of the turbine 3 to generate electricity.
[0063] The gas turbine combustor 2 is contained in a combustor casing 6 and a combustor cover 7 . A fuel nozzle 8 is provided centrally of an upstream end of the gas turbine combustor 2 , downstream of which fuel nozzle is provided a substantially cylindrical-shaped combustor liner 9 for isolation of combustion air and combustion gas.
[0064] High pressure air 102 obtained by compression of gas turbine intake air 100 (atmospheric pressure) at the compressor 1 inlet by means of the compressor 1 flows between a transition piece 11 and a transition piece flow sleeve 12 to perform convection-cooling of the transition piece 11 to make unhumidified high temperature air 103 .
[0065] The unhumidified high temperature air 103 is fed to the humidifier 4 to have moisture added thereto to make humidified air 104 . The humidifier 4 humidifies air by means of water spraying. Here, the humidified air 104 humidified by the humidifier 4 is put in a state below the vapor saturation condition (less than the relative humidity 100%).
[0066] In order to monitor the soundness of the humid air gas turbine, a thermometer for measurement of humidifier outlet temperature 500 is provided at the humidifier 4 outlet.
[0067] The humidified air 104 , to which moisture is added in the humidifier 4 , is led to the regenerator 5 to be heated in heat exchange with gas turbine exhaust gas 107 (turbine outlet low-pressure combustion gas).
[0068] The humidified air 104 thus heated makes high-temperature high-humidity air 105 to be poured into the combustor casing 6 . The high-temperature high-humidity air 105 in the combustor casing 6 passes through a substantially annular-shaped space outside of the combustor liner 9 to flow toward a combustor head of the gas turbine combustor 2 to be used for convection-cooling of the combustor liner 9 in mid course.
[0069] Part of the high-temperature high-humidity air 105 flows into the combustor liner 9 from a cooling port provided in the combustor liner 9 to be used for film cooling. The remainder of the high-temperature high-humidity air 105 ( 36 in Part A in the drawing) flows into the combustor liner 9 from an air port 32 described below to be used for combustion in the gas turbine combustor 2 together with fuel jetted from the fuel nozzles 31 to make high-temperature combustion gas 106 to be fed to the turbine 3 .
[0070] Turbine outlet low-pressure combustion gas 107 leaving the turbine 3 has its heat recovered in the regenerator 5 to make regenerator outlet low-pressure combustion gas 108 to be exhausted as exhaust gas 109 from an exhaust tower 22 .
[0071] Driving force obtained in the turbine 3 is transmitted to the compressor 1 and the generator 20 through a shaft 21 . Part of the driving force makes compressive power for air in the compressor 1 and the remainder of the driving force is converted into electricity in the generator 20 .
[0072] Generated output MW being an output of a humid air gas turbine generating plant is controlled by regulation of opening and closing of fuel flow control valves 211 to 214 , which calculates fuel flow rate supplied to the gas turbine combustor 2 on the basis of a command signal from a control unit 1000 .
[0073] Water quantity for humidification of air in the humidifier 4 is controlled by regulation of opening and closing of a humidifier spray water quantity control valve 311 by means of a command signal from the control unit 1000 .
[0074] FIG. 2 is a view showing the construction of a fuel nozzle 9 provided in the gas turbine combustor 2 , according to the embodiment, used in the humid air gas turbine shown in FIG. 1 .
[0075] A multiplicity of fuel nozzles 31 are mounted to a fuel nozzle header 30 provided on the combustor cover 7 of the gas turbine combustor 2 and an air hole plate 33 provided with a multiplicity of air holes 32 , each of which is conformed to each of the multiplicity of fuel nozzles 31 , is mounted to the combustor cover 7 through a support 34 .
[0076] The fuel nozzles 31 and the air holes 32 formed through the air hole plate 33 are arranged substantially concentrically to form a fuel jet 35 centrally and a multiplicity of coaxial air jets 36 therearound as shown in Part A of FIG. 2 .
[0077] Since fuel and air are unmixed in the air holes 32 formed through the air hole plate 33 owing to the coaxial jet configuration, selfignition of the fuel is not caused even when combustion air is high in temperature as in a humid air gas turbine and so the air hole plate 33 does not suffer dissolution loss, so that the gas turbine combustor 2 can be made high in reliability.
[0078] Since such small coaxial jets are formed in multiplicity to cause an increase in fuel and air interfaces and promotion in mixing, it is possible to restrict a NOx yield during combustion in the gas turbine combustor 2 .
[0079] FIG. 3 is a view showing the air hole plate 33 provided in the gas turbine combustor 2 of the embodiment as viewed from a downstream side of the combustor. In the gas turbine combustor 2 of the embodiment, the multiplicity of air holes 32 (while not shown, the fuel nozzles 31 pairing with the air holes 32 ) are arranged concentrically in eight annular air hole rows from a radially inner peripheral side of the air hole plate 33 to a radially outer peripheral side.
[0080] Burners constituting a combustion part of the gas turbine combustor 2 are grouped into F1 burners arranged in four rows (first to fourth rows) around a center to form a first group (F1) combustion part, F2 burners arranged in a fifth row to form a second group (F2) combustion part, F3 burners arranged in two rows (sixth and seventh rows) outside thereof to form a third group (F3) combustion part, and F4 burners arranged in an outermost periphery (eighth row) to form a fourth group (F4) combustion part, and as shown in FIG. 2 , fuel supplied from fuel lines 201 to 204 , respectively, provided with the flow control valves 211 to 214 is fed to the fuel nozzles 31 through flanges 51 to 54 provided on the header 30 for the respective groups of F1 burners to F4 burners.
[0081] Such grouped configuration of the fuel lines 201 to 204 enables fuel staging, in which the fuel nozzles for fueling are varied stepwise in number to conform to a change in fuel flow for the gas turbine, whereby it is possible to ensure the combustion stability at the time of gas turbine partial load operation and to make NOx low.
[0082] Those air holes 32 on the air hole plate 33 , which are centrally arranged in four rows (F1) to constitute F1 burners, are formed in the shape of slant holes, which are angled (a° in FIG. 3 ) in a pitch circle tangential direction, whereby the whole air flow passing through the air holes 32 is revolved and a circulating flow thus generated makes flame stable.
[0083] In F2 to F4 burners arranged on an outer peripheral side of F1 burners, flame is stabilized by combustion heat of the central F1 burners. Accordingly, when humidification is started in the humid gas turbine to cause an increase in combustion air, F1 flame is improved in combustion stability by increasing the fuel flow supplied to F1 burners of the gas turbine combustor 2 and thus producing a high temperature part locally.
[0084] While F2 burners and the following burners are decreased in fuel flow as fuel supplied to F1 burners is increased, combustion stability in the whole burners is ensured since flame in the former is stabilized by combustion heat of F1 burners.
[0085] An example of the operating method of the humid air gas turbine, to which the fuel flow control method and the fuel flow control system of the gas turbine combustor 2 according to the embodiment are applied, will be described with reference to respective characteristics graphs shown in FIGS. 4 and 5 .
[0086] In the characteristics graph of FIG. 4 for the operating method of the humid air gas turbine, an axis of abscissas indicates time from starting and an axis of ordinate indicates number of revolution, electric power generation, air flow rate, spray water quantity of the humidifier 4 , outlet humidity of the humidifier 4 , and outlet temperature 500 of the humidifier 4 , respectively, in order from the top.
[0087] In the characteristics graph of FIG. 5 for the operating method of the humid air gas turbine, an axis of abscissas indicates time from starting as in FIG. 4 and an axis of ordinate schematically indicates combustion temperature of the gas turbine combustor 2 , whole fuel flow rate of the gas turbine combustor 2 , and individual fuel flow rates (F1 flow rate to F4 flow rate) of the respective fuel lines 201 to 204 , through which fuel is supplied to F1 to F4 burners, in order from the top.
[0088] In the characteristics graphs of FIG. 4 and FIG. 5 , time a indicates a revolution increasing time from starting to attainment of a rated revolution, time b indicates time, during which combustion temperature after humidification is equal to or lower than temperature Tg 1 , during a load increasing time in starting of the gas turbine, time c indicates time, during which combustion temperature after humidification is equal to or higher than temperature Tg 1 and is higher than Tg 1 but equal to or lower than temperature Tg 2 , during a load increasing time in starting of the gas turbine, and time d indicates a load-following operation time after termination of starting.
[0089] The load increasing time b further is divided into moisture non-addition time b 1 in the first half, moisture addition varying time b 2 , and moisture addition constant time b 3 . Here, combustion temperature of the gas turbine combustor 2 is made to assume a value found from fuel-air ratio (ratio of fuel flow rate and air flow rate), combustion air temperature, and combustion air humidity.
[0090] In the operating method of the fuel flow control system of the gas turbine combustor 2 of the embodiment in a humid air gas turbine, first at the time of ignition and revolution increasing, during which fuel flow rate is relatively small, only F1 burners positioned around the axis of the gas turbine combustor 2 are caused by a command from the control unit 1000 of the fuel flow control system to burn for operation (that is, F1 fuel is supplied to only the fuel line 201 in FIG. 2 ) to increase revolution near the rated revolution no-load condition. Such separate combustion of F1 burners is referred to as ¼ mode in the following description.
[0091] Subsequently, in the following load increasing process (time b), F2 fuel is charged into F2 burners arranged on the outer peripheral side of F1 burners of the gas turbine combustor 2 for operation in (F1+F2). That is, F1 fuel and F2 fuel are supplied to the fuel lines 201 and 202 and a command from the control unit 1000 regulates opening degrees of the flow control valves 211 and 212 , respectively, provided on the fuel lines 201 and 202 to control fuel flow rates of F1 fuel and F2 fuel, respectively. This operation is referred to as 2/4 mode.
[0092] Further, a state, in which F3 fuel is supplied to the fuel line 203 for charging of fuel into F3 burners arranged on the outer peripheral side of F2 burners of the gas turbine combustor 2 to cause ignition on F3 burners, is referred to as ¾ mode.
[0093] In the preceding process, moisture is not added to the humidifier 4 of the humid air gas turbine (b 1 ). Specifically, the humidifier feed valve 311 for regulation of water flow rate supplied to the humidifier 4 of the humid air gas turbine shown in FIG. 1 is fully closed.
[0094] In this course, respective fuel flow rates of F1 fuel, F2 fuel, and F3 fuel, respectively, supplied to F1 burners, F2 burners, and F3 burners are controlled by regulating the opening degrees of the flow control valves 211 , 212 , and 213 so that gas turbine power generation increases in accordance with a load increasing rate determined in the starting plan of the gas turbine.
[0095] Flow rates of F1 fuel, F2 fuel, and F3 fuel supplied to F1 burners, F2 burners, and F3 burners through the respective fuel lines 201 to 203 are distributed at a rate determined so that combustion in the gas turbine combustor 2 is made stable and NOx thus generated is made minimum.
[0096] In the fuel flow control method and the fuel flow control system of the gas turbine combustor 2 according to the embodiment, addition of moisture to the humidifier 4 of the humid air gas turbine is started in ¾ mode. In accordance with a humidification starting command, a command signal from the control unit 1000 opens the air cooler side humidifier feed water valve 311 provided on the humidifier 4 , so that water of flow rate conformed to the opening degree is poured into the humidifier 4 (time b 2 ).
[0097] Then the opening degree of the air cooler side humidifier feed valve 311 is controlled for regulation so that the quantity of water flowing in the air cooler 28 assumes a predetermined value (time b 2 to b 3 ).
[0098] At this time, a command signal from the control unit 1000 controls respective fuel flow rates supplied to F1 burners, F2 burners, and F3 burners of the gas turbine combustor 2 so that gas turbine power generation increases in accordance with a load increasing rate determined in the starting plan of the gas turbine. In order to mainly serve ensuring combustion stability, it is required that F1 fuel supplied to F1 burners be set so that a ratio of F1 fuel flow rate to the whole fuel flow rate is increased after the starting of humidification by the humidifier 4 in comparison to that before the starting of humidification.
[0099] In the characteristics graph of the operating method of the gas turbine system provided with the gas turbine combustor of the embodiment shown in FIG. 5 , straight line portions indicated by dotted lines indicate setting before humidification. In the gas turbine combustor 2 of the embodiment, fuel flow rate supplied to F1 burners is set so that as F1 flow rate is increased as shown by the solid line relative to the straight line portion indicated by the dotted line, fuel flow rate supplied to F3 burners is set to decrease F3 flow rate as shown by the solid line relative to the straight line portion indicated by the dotted line.
[0100] Determination based on F1 combustion temperature is effective to determine an optimum F1 flow rate for ensuring the combustion stability of the gas turbine combustor 2 .
[0101] Among various elements required for combustion temperature calculation, realtime direct measurement of combustion air temperature by a humidity sensor is problematically difficult as described above.
[0102] Hereupon, it is examined in the gas turbine combustor 2 of the embodiment to use the control unit 1000 of the fuel flow control system to evaluate humidifier outlet humidity Hm h, exit , which is outlet humidity of the humidifier 4 , from humidifier spray water quantity G wh, sp , which is spray water quantity fed to the humidifier 4 .
[0103] As compared with humidity measurement by a humidity sensor, it is easy to measure humidifier spray water quantity G wh, sp with high accuracy at high speed. Accordingly, realtime evaluation of the humidifier outlet humidity Hm h, exit is made possible provided that it is possible to one to one evaluate humidifier outlet humidity Hm h, exit from humidifier spray water quantity G wh, sp .
[0104] In the case where residence time in the humidifier 4 is sufficiently ensured, while humidifier spray water quantity G wh, sp is small, humidification of air is easy due to being far from the vapor saturation condition, but it is thought that when humidifier spray water quantity G wh, sp is large, humidification of air is made hard due to being near to the vapor saturation condition.
[0105] Specifically, it is thought that when humidifier spray water quantity G wh, sp is infinite, humidifier outlet humidity Hm h, exit comes close to humidifier outlet maximum humidity Hm h, max . Under an ideal condition, humidifier outlet maximum humidity Hm h, max is saturated humidity Hm h, sat at humidifier outlet temperature 500 .
[0106] A schematic diagram of FIG. 6 shows the relationship between humidifier spray water quantity G wh, sp and humidifier outlet humidity Hm h, exit for the humidifier 4 . The relationship can be found by means of an actual measurement value put into data base or a calculating formula, in which humidification is simulated.
[0107] In the schematic diagram of FIG. 6 showing the relationship between humidifier spray water quantity and humidifier outlet humidity for the humidifier 4 in the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention, a curve is shown, along which humidifier outlet humidity Hm h, exit continuously rises in value when humidifier spray water quantity G wh, sp increases.
[0108] As in a schematic diagram (approximate diagram) of FIG. 7 showing the relationship between humidifier spray water quantity and humidifier outlet humidity for the humidifier 4 in the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention, approximation can also be made by means of a straight line obtained by finding several values of humidifier outlet humidity Hm h, exit relative to humidifier spray water quantity G wh, sp and connecting the values by straight lines.
[0109] Combustion temperature in the gas turbine combustor 2 can be calculated from combustion air temperature and fuel-air ratio by means of combustion air humidity used in the control unit 1000 provided in the fuel flow control system of the gas turbine combustor 2 , according to the embodiment, shown in FIG. 9 . F1 flow rate required for stable combustion is found by calculating combustion temperature for F1 burners, of which a flame stabilizing quality is heightened, and making a comparison among F1 combustion temperatures needed for stable combustion.
[0110] The humidity calculating method in the control unit 1000 provided in the fuel flow control system of the gas turbine combustor 2 according to the embodiment is effective not only in that time (time b 3 in FIG. 4 ), during which humidifier spray water quantity 301 for the humidifier 4 is constant, but also in that time (time b 2 in FIG. 4 ), during which humidifier spray water quantity 301 varies. Accordingly, for a transient humidity change of combustion air due to a change in humidifier spray water quantity 301 , combustion stability can be ensured by setting of an appropriate F1 flow rate.
[0111] Using the characteristics graphs of FIGS. 4 and 5 showing another example of the operating method of the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention, an explanation will be given to a state after humidification as planned is reached.
[0112] In the gas turbine combustor 2 of the embodiment, when fuel is increased in order to raise a load to a predetermined one with humidification constant, combustion temperature reaches temperature Tg 1 . When local combustion temperature is equal to or higher than temperature for generation of NOx, NOx is easily generated despite of high humidity combustion.
[0113] Here, it is known from results of element combustion tests that stable combustion in the gas turbine combustor 2 is made possible even in high humidity combustion when combustion temperature in the gas turbine combustor 2 rises to some extent. So, in operating the humid air gas turbine system provided with the gas turbine combustor according to the embodiment, when combustion temperature in the gas turbine combustor 2 becomes equal to or higher than temperature Tg 1 , F1 flow rate having thus been increased is gradually decreased and F3 flow rate is gradually increased as shown in FIG. 5 .
[0114] When combustion temperature in the gas turbine combustor 2 reaches temperature Tg 2 being higher than temperature Tg 1 , F1 flow rate is set so that local combustion temperatures in F1 burners and F3 burners become equivalent to each other.
[0115] Thus, during that time (time c in FIGS. 4 and 5 ), in which combustion temperature in the gas turbine combustor 2 is equal to or higher than temperature Tg 1 but equal to or lower than temperature Tg 2 , F1 flow rate is decreased conversely to that in time b to enable realizing stable combustion and a further low NOx combustion in the gas turbine combustor 2 over the whole load zone.
[0116] FIG. 8 is a characteristics graph showing a further example of the operating method of the humid air gas turbine system provided with the gas turbine combustor of the first embodiment of the invention, and in the graph, F1 flow rate and F3 flow rate are taken up and enlarged for time b 2 , time b 3 , and time c in FIG. 5 .
[0117] In the operating method of the humid air gas turbine system provided with the gas turbine combustor, according to the embodiment, shown in the characteristics graph of FIG. 8 , straight line portions indicated by dotted lines indicate flow rates, at which combustion temperatures of F1 and F3 burners in the gas turbine combustor 2 are equivalent to each other, and portions shown by solid lines indicate operations corresponding to those shown in FIG. 5 .
[0118] In the portions shown by the solid lines in the characteristics graph of FIG. 8 , F1 flow rate is set high just after the starting of humidification by the humidifier 4 and in that time c, during which combustion temperature becomes equal to or higher than temperature Tg 1 , fuel flow rate is controlled so that combustion temperatures in F1 and F3 become equivalent to each other in a stage, in which stable combustion is ensured.
[0119] Unless the gas turbine combustor 2 is problematic in combustion stability, a simple flow control shown by alternate long and short dash lines is possible. In the flow control shown by alternate long and short dash lines, flow control lines can be determined only by determining F1 flow rate supplied to F1 burners at temperature Tg 1 in the gas turbine combustor 2 , so that setting of control is facilitated.
[0120] At a point of time when power generation or turbine exhaust temperature reaches a predetermined value, starting of the humid air gas turbine is completed and thereafter fuel flow rate supplied to the gas turbine combustor 2 increases or decreases in accordance with an increase or a decrease in load on the humid air gas turbine to follow a load (time d).
[0121] In a high load operation of the humid air gas turbine, F4 fuel supplied to F4 burners, positioned on the outermost periphery, among F1 burners to F4 burners provided in the gas turbine combustor 2 is mainly increased or decreased in flow rate. At this time, since a mixture of F4 fuel and air mixes with combustion gases of F1 to F3 burners to become high in temperature, the fuel oxidation reaction slowly advances to enable obtaining a high combustion efficiency.
[0122] Since air distribution is set so that temperature after completion of combustion becomes equal to or lower than one, at which generation of NOx becomes conspicuous, combustion, in which generation of NOx from F4 burners is made almost zero, is enabled. Since the reaction is completed even when F4 fuel charged into F4 burners is slight, a continuous fuel exchange is enabled to achieve an improvement in operability.
[0123] FIG. 9 shows an example of a concrete control block constituting the control unit 1000 in the fuel flow control system of the gas turbine combustor 2 of the embodiment provided in a humid air gas turbine.
[0124] As in the concrete control block constituting the control unit 1000 provided in the fuel flow control system, shown in FIG. 9 , of the gas turbine combustor 2 of the embodiment provided in a humid air gas turbine, a subtracter 401 provided in the control unit 1000 is used to find a deviation between a load command MWD given in accordance with a predetermined electric power generation increasing rate and an actual electric power generation MW, and a fuel flow control unit 402 is provided to calculate and output a fuel flow command 410 to an actual fuel flow control unit 406 , which controls valve opening degrees of the F1 fuel flow control valve 211 to the F4 fuel flow control valve 214 for supplying to F1 burners to F4 burners of the gas turbine combustor 2 , on the basis of that deviation between a load command MWD and an actual electric power generation MW, which is found by the subtracter 401 .
[0125] The fuel flow command 410 calculated in the fuel flow control unit 402 provided in the control unit 1000 is input into a fuel flow rate ratio setter 403 provided in the control unit 1000 .
[0126] A humidifier outlet maximum humidity computing unit 408 provided in the control unit 1000 inputs thereinto humidifier outlet temperature 500 measured by the thermometer provided at the outlet of the humidifier 4 to calculate humidifier outlet maximum humidity Hm h, max , and a humidifier outlet humidity computing unit 404 calculates humidifier outlet humidity Hm h, exit from the humidifier outlet maximum humidity Hm h, max calculated by the humidifier outlet maximum humidity computing unit 408 and that humidifier spray water quantity G wh, sp , which is humidifier spray water quantity 301 sprayed into the humidifier 4 .
[0127] Humidifier outlet humidity Hm h, exit calculated by the humidifier outlet humidity computing unit 404 is input into a humidity F1 gain computing unit 405 and a combustion temperature F1 gain computing unit 415 provided in the control unit 1000 , respectively.
[0128] The humidity F1 gain computing unit 405 calculates F1 gain relative to humidity on the basis of humidity Hm h, exit . The combustion temperature F1 gain computing unit 415 calculates F1 gain relative to combustion temperature from combustion air flow rate, the fuel flow command 410 calculated by the fuel flow control unit 402 , and humidifier outlet humidity Hm h, exit calculated by the humidifier outlet humidity computing unit 404 .
[0129] A product of output of the humidity F1 gain computing unit 405 and output of the combustion temperature F1 gain computing unit 415 is found by a multiplier 416 provided in the control unit 1000 to calculate F1 gain 417 , the F1 gain 417 being input into the fuel flow rate ratio setter 403 provided in the control unit 1000 .
[0130] FIG. 10 is a schematic diagram showing an example of outputs of the humidity F1 gain computing unit 405 and the combustion temperature F1 gain computing unit 415 provided in the control unit 1000 , and F1 gain 17 calculated from such outputs by the multiplier 416 .
[0131] As shown in FIG. 10 , F1 gain 417 for realization of F1 flow rate supplied to F1 burners and shown in FIGS. 5 and 8 can be calculated from humidity and combustion temperature.
[0132] The following methods serve to make a low NOx and stable combustion compatible with each other in the gas turbine combustor 2 of the embodiment.
[0133] First, F1 gain 417 is increased as humidifier outlet humidity Hm h, exit increases. Stable combustion is enabled by having F1 gain 417 following a humidity increase.
[0134] A low NOx and stable combustion can be made compatible with each other in the gas turbine combustor 2 by setting F1 gain so as to gradually decrease the same so that after combustion temperature in the gas turbine combustor 2 becomes equal to or higher than combustion temperature Tg 1 , at which stable combustion can be ensured, after humidification in the humidifier 4 , local combustion temperatures of F1 burners to F4 burners in the gas turbine combustor 2 become equivalent to combustion temperature Tg 2 , at which all combustion temperatures of F1 burners to F4 burners in the gas turbine combustor 2 become equal to one another.
[0135] Secondly, as humidifier outlet humidity Hm h, exit increases, F1 gain 417 is increased so that F1 combustion temperature in the gas turbine combustor 2 becomes constant. Stable combustion and low NOx combustion can be made compatible with each other in the gas turbine combustor 2 by setting F1 gain 417 so as to increase F1 fuel flow rate in accordance with an increase in humidity so that F1 combustion temperature becomes the same irrespective of a change in humidity.
[0136] Then, a low NOx and stable combustion can be made compatible with each other in the gas turbine combustor 2 by setting F1 gain 417 so as to gradually decrease the same so that after combustion temperature after humidification becomes equal to or higher than combustion temperature Tg 1 , local combustion temperatures of F1 burners to F4 burners become equivalent to combustion temperature Tg 2 .
[0137] Thirdly, as humidifier outlet humidity Hm h, exit increases, F1 gain 417 is increased so that F1 combustion temperature in the gas turbine combustor 2 becomes high. It is thought that when humidity increases, a decrease in combustion stability is caused depending upon a combustion condition.
[0138] The gas turbine combustor 2 can be heightened in combustion stability against a change in humidity by setting F1 gain 417 so that F1 combustion temperature rises in accordance with an increase in humidity, and thus a further improvement in reliability is achieved.
[0139] A low NOx and stable combustion can be made compatible with each other in the gas turbine combustor 2 by setting F1 gain 417 so as to gradually decrease the same so that after combustion temperature after humidification becomes equal to or higher than combustion temperature Tg 1 , local combustion temperatures of F1 burners to F4 burners become equivalent to combustion temperature Tg 2 .
[0140] Hereupon, with the control unit 1000 of the gas turbine combustor 2 of the embodiment, as shown in FIG. 9 , the fuel flow rate ratio setter 403 provided in the control unit 1000 inputs thereinto a fuel flow command 410 output from the fuel flow control unit 402 likewise provided in the control unit 1000 to calculate respective fuel flow ratios ( 411 to 414 ) of F1 to F4 with reference to the value of F1 gain 417 .
[0141] The actual fuel flow control unit 406 provided in the control unit 1000 calculates flow rates or valve opening degrees of respective fuel lines of F1 to F4 from respective fuel flow rate ratios ( 411 to 414 ) of F1 to F4 calculated by and output from the fuel flow rate ratio setter 403 and a fuel flow command 410 output from the fuel flow control unit 402 to output the same to the fuel flow control valves 211 to 214 to control the valve opening degrees of the fuel flow control valves 211 to 214 , respectively.
[0142] Thus, with the gas turbine combustor 2 of the embodiment, the control unit 1000 constituted as shown in FIG. 9 can realize exercising the fuel flow rate control indicated by the solid lines in FIG. 5 .
[0143] It is thought that time lag is caused by valve control and a volume of an associated system until moisture is actually added to combustion air after starting of humidification. At this time, a low NOx and stable combustion can be made compatible with each other in the gas turbine combustor 2 provided that an actual combustion air humidity is estimated taking account of first order lag with respect to combustion air humidity.
[0144] When a gas turbine load decreases, the above matter is especially effective since it is thought that a volume of a system such as piping or the like causes lag until combustion air humidity follows humidifier spray water quantity 301 in the humidifier 4 .
[0145] Further, since combustion air humidity rapidly decreases in the case where a spray water feed rate to the humidifier 4 is suddenly decreased or spray water supplying is stopped due to some circumstances, it is possible that F1 combustion temperature in the gas turbine combustor 2 becomes too high.
[0146] According to the embodiment, since a method for estimating combustion air humidity from feed water quantity enables detection of variation in combustion air humidity, it is possible to avoid a rapid increase in F1 combustion temperature in the gas turbine combustor 2 , thus achieving an improvement of a gas turbine in reliability.
[0147] Thus, according to the embodiment, a fuel flow control method and a fuel flow control system of a humid air gas turbine combustor, which are capable of operation in high reliability before humidification, before and after starting of humidification, and during humidification without damage in combustion stability and of maintaining a NOx yield in low level irrespective of a humidified condition, can be realized in a humid air gas turbine for humidification of air with a spray type humidifier.
Embodiment 2
[0148] Subsequently, a fuel flow control method and a fuel flow control system of a gas turbine combustor, according to a second embodiment of the invention, provided in a humid air gas turbine will be described with reference to FIGS. 11 to 13 .
[0149] Since the fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine is common in fundamental constitution to the fuel flow control system of the gas turbine combustor of the first embodiment provided in a humid air gas turbine and shown in FIGS. 1 to 10 , descriptions of the constitution and function common to the both are omitted and a different portion will be described below.
[0150] FIG. 11 is a characteristics graph showing an example of the operating method of the humid air gas turbine according to the second embodiment of the invention, the characteristics graph of FIG. 11 corresponding to the characteristics graph of FIG. 4 of the first embodiment.
[0151] A difference between the fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine and the fuel flow control system of the gas turbine combustor of the first embodiment provided in a humid air gas turbine resides in that humidifier outlet humidity in a humidifier 4 is not evaluated directly, but humidifier outlet vapor quantity G vh, exit in the humidifier 4 is first found and combustion air humidity is calculated from humidifier outlet vapor quantity G vh, exit thus found.
[0152] Humidifier outlet humidity Hm h, exit in the humidifier 4 can be evaluated with high accuracy by evaluating combustion air humidity from humidifier outlet vapor quantity G vh, exit .
[0153] FIG. 12 is a schematic diagram showing the relationship between humidifier spray water quantity G wh, sp and humidifier outlet vapor quantity G vh, exit in the humidifier 4 in a humid air gas turbine system provided with the gas turbine combustor of the embodiment. The schematic diagram of FIG. 12 shows a curve, along which humidifier outlet humidity Hm h, exit comes close to humidifier outlet maximum humidity Hm h, max when humidifier spray water quantity G wh, sp increases.
[0154] In the humid air gas turbine according to the embodiment, it is thought likewise in the schematic diagram of FIG. 12 that when humidifier spray water quantity G wh, sp increases, humidifier outlet vapor quantity G vh, exit comes close to humidifier outlet maximum vapor quantity G vh, max .
[0155] Under an ideal condition, humidifier outlet maximum vapor quantity G vh, max in the humidifier 4 makes saturated vapor quantity G vh, sat relative to humidifier outlet flow rate and temperature. For example, humidifier outlet vapor quantity G vh, exit in the humidifier 4 is proportional to humidifier outlet maximum vapor quantity G vh, max and is given by a function proportional to a difference between a unit quantity and an exponential function value, of which a variable is a value obtained by multiplying humidifier spray water quantity G wh, sp by a minus proportional constant.
[0156] Specifically, the relationship between humidifier spray water quantity G wh, sp and humidifier outlet vapor quantity G vh, exit in the humidifier 4 is represented by the formula (1).
[0000] G vh, exit =G vh, max (1−exp(− C·G wh, sp )) (1)
[0000] Here, C is a constant.
[0157] FIG. 13 shows an example of a concrete control block constituting a control unit 1000 in the fuel flow control system of the gas turbine combustor 2 of the embodiment provided in a humid air gas turbine.
[0158] In the control unit 1000 in the fuel flow control system of the gas turbine combustor 2 of the embodiment shown in FIG. 13 , a humidifier outlet maximum vapor quantity computing unit 409 inputs thereinto humidifier outlet temperature 500 measured by a thermometer provided at the outlet of the humidifier 4 to calculate humidifier outlet maximum vapor quantity G vh, max and a humidifier outlet vapor quantity computing unit 407 calculates humidifier outlet vapor quantity G vh, exit from humidifier outlet maximum vapor quantity G vh, max calculated by the humidifier outlet maximum vapor quantity computing unit 409 and humidifier spray water quantity G wh, sp being humidifier spray water quantity 301 sprayed to the humidifier 4 .
[0159] Humidifier outlet vapor quantity G vh, exit calculated by the humidifier outlet vapor quantity computing unit 407 is input into the humidifier outlet humidity computing unit 404 . The remaining constitution of the control block is the same as that of the control unit 1000 of the first embodiment shown in FIG. 9 .
[0160] Thus the fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine enables finding F1 gain required for stable combustion with respect to combustion air humidity, which varies every moment, in the same manner as in the first embodiment and further evaluating humidity of combustion air, which flows into the gas turbine combustor, with high accuracy, thereby enabling realizing a highly reliable operation, in which a low NOx and stable combustion are made further exactly compatible with each other.
[0161] Accordingly, according to the embodiment, a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine, which are capable of operation in high reliability before humidification, before and after the starting of humidification, and during humidification without damage in combustion stability and of maintaining a NOx yield in low level irrespective of a humidified condition, can be realized in a humid air gas turbine for humidification of air with the use of a spray type humidifier.
Embodiment 3
[0162] A fuel flow control method and a fuel flow control system of a gas turbine combustor, according to a third embodiment of the invention, provided in a humid air gas turbine will be described with reference to FIGS. 14 to 18 .
[0163] Since a fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine is common in fundamental constitution to the fuel flow control system of the gas turbine combustor of the first embodiment provided in a humid air gas turbine and shown in FIGS. 1 to 10 , descriptions of the constitution and function common to the both are omitted and a different portion will be described below.
[0164] FIG. 14 is a system flow diagram showing the whole constitution of the humid air gas turbine system according to the third embodiment of the invention and a difference between the humid air gas turbine system of the embodiment and the fuel flow control system of the first embodiment resides in that an intake spray device 23 sprays water onto gas turbine intake air 100 , the intake air being compressed by a compressor 1 as intake air 101 after water spraying.
[0165] In the humid air gas turbine system according to the embodiment, the intake spray device 23 sprays water onto intake air to thereby enable sharply reducing compression power of the compressor 1 .
[0166] In the humid air gas turbine system according to the embodiment, unhumidified high temperature air 103 flows into the humidifier 4 in a state of being humidified in the intake spray device 23 unlike the first embodiment. Accordingly, in the case where unhumidified high temperature air 103 has already been humidified, it is necessary to catch how humidified air 104 humidified in the humidifier 4 varies in humidity relative to flow rate of humidifier spray water 301 sprayed into the humidifier 4 .
[0167] An example of the operating method of a humid air gas turbine system, to which the fuel flow control method and the fuel flow control system of the gas turbine combustor 2 , according to the embodiment, shown in FIG. 14 are applied, will be described with reference to graphs shown in FIGS. 15 and 16 .
[0168] In the characteristics graph of FIG. 15 for the operating method of the humid air gas turbine, an axis of abscissas indicates time from starting as in FIG. 4 and an axis of ordinate indicates number of revolution, electric power generation, air flow rate, spray water quantity (humidifier spray water quantity 301 and compressor intake spray water quantity 300 ), humidifier outlet humidity of the humidifier 4 , and humidifier outlet temperature 500 of the humidifier 4 , respectively, in order from the top.
[0169] In the characteristics graph of FIG. 16 for the operating method of the humid air gas turbine, an axis of abscissas indicates time from starting as in FIG. 15 and an axis of ordinate schematically indicates combustion temperature of the gas turbine combustor 2 , whole fuel flow rate of the gas turbine combustor 2 , and respective fuel flow rates (F1 flow rate to F4 flow rate) of respective fuel lines 201 to 204 , through which fuel is supplied to F1 to F4 burners, in order from the top.
[0170] In the characteristics graphs of FIG. 15 and FIG. 16 , time a indicates revolution increasing time from starting to attainment of rated revolution, time b indicates load increasing time in starting of the gas turbine, and time c indicates load-following operation time after termination of starting.
[0171] The load increasing time b is divided into non-humidification time b 1 , humidification varying time b 2 in the humidifier 4 , humidification constant time b 3 in the humidifier 4 , spray water quantity varying time b 4 in the intake spray device 23 , and spray water quantity constant time b 5 in the intake spray device 23 , respectively.
[0172] Time (time b 1 to time b 3 in FIG. 4 ) elapsed until humidification is made constant after humidification is started in the humidifier 4 is the same as that in the first embodiment of the invention.
[0173] In the operating method of the humid air gas turbine of the embodiment, intake spraying is started in the intake spray device 23 after humidification is made constant in the humidifier 4 . A intake spraying starting command opens an intake spray water quantity control valve 310 , feed water of flow rate conformed to the opening degree is supplied to the intake spray device 23 to stepwise increase intake spray water quantity (time b 4 ), and spray water quantity is regulated so as to assume a predetermined value (time b 4 to time b 5 ).
[0174] A manner, in which the ratio of F1 flow rate in the gas turbine combustor 2 of the embodiment provided in a humid air gas turbine to a change in humidity is increased to raise F1 combustion temperature, thus making the gas turbine combustor 2 stable in combustion, is the same as that in the first embodiment of the invention.
[0175] Also, in the operating method of the humid air gas turbine of the embodiment, a similar relationship to that shown in the schematic diagram of FIG. 6 is established between humidifier spray water quantity G wh, sp and humidifier outlet humidity Hm h, exit in the humidifier 4 in the same manner as that in the first embodiment of the invention.
[0176] FIG. 17 shows a schematic diagram showing the relationship between humidifier spray water quantity G wh, sp and humidifier outlet humidity Hm h, exit in the humidifier 4 in the operating method of the humid air gas turbine of the embodiment.
[0177] In the schematic diagram of FIG. 17 , humidifier outlet humidity Hm h, exit indicated by a dotted line is humidifier outlet humidity Hm h, exit in the case where intake spraying cooling is carried out, and humidifier outlet humidity Hm h, exit indicated by a solid line is humidifier outlet humidity Hm h, exit in the case where intake spraying cooling is not carried out, the schematic diagram corresponding to FIG. 6 related to the first embodiment of the invention.
[0178] In the operating method of the humid air gas turbine of the embodiment, unhumidified high temperature air 103 is humidified by the intake spray device 23 , so that when humidifier spray water quantity G wh, sp for the humidifier 4 is zero, humidifier outlet humidity Hm h, exit in the humidifier 4 is not made zero as indicated by the dotted line in FIG. 17 . That is, when humidifier spray water quantity G wh, sp =0, humidifier outlet humidity Hm h, exit is equal to compressor outlet humidity Hm c, exit .
[0179] Humidifier outlet humidity Hm h, exit is a change in humidity, which is caused by humidification from an intake part of the compressor 1 , in which the intake spray device 23 is included, to a discharge part of the compressor 1 .
[0180] The relationship, shown in the schematic diagram of FIG. 17 , between humidifier spray water quantity G wh, Sp and humidifier outlet humidity Hm h, exit for the humidifier 4 can be found by means of an actual measurement value put into data base or a calculating formula, in which humidification is simulated, in the same manner as that shown in FIG. 6 .
[0181] FIG. 18 shows an example of a concrete control block constituting a control unit 1000 in the fuel flow control system of the gas turbine combustor 2 of the embodiment provided in a humid air gas turbine.
[0182] A difference between the control unit 1000 and the control unit in the fuel flow control system of the gas turbine combustor 2 of the first embodiment resides in that in a humid air gas turbine system, in which the intake spray device 23 is provided upstream of the compressor 1 , compressor outlet humidity Hm c, exit is changed by the operating condition of the intake spray device 23 , that is, intake spray water quantity G wc, wac .
[0183] A humidifier outlet maximum humidity computing unit 408 provided in the control unit 1000 of the embodiment inputs thereinto humidifier outlet temperature 500 measured by a thermometer provided at the outlet of the humidifier 4 to calculate humidifier outlet maximum humidity Hm h, max , and a humidifier outlet humidity computing unit 404 calculates humidifier outlet humidity Hm h, exit from the humidifier outlet maximum humidity Hm h, max calculated by the humidifier outlet maximum humidity computing unit 408 , humidifier spray water quantity G h, Sp , which is humidifier spray water quantity 301 sprayed into the humidifier 4 , and intake spray device spray water quantity G wc, wac sprayed from the intake spray device 23 , thus coping with variation in the compressor outlet humidity Hm c, exit .
[0184] Humidifier outlet humidity Hm h, exit calculated by the humidifier outlet humidity computing unit 404 calculates the humidifier outlet humidity Hm h, exit taking account of not only humidifier spray water quantity G wh, sp but also intake spray device spray water quantity G wc, wac to enable evaluating combustion air humidity with a higher accuracy even in a humid air gas turbine system provided with the intake spray device 23 . The remaining constitution of the control block is the same as that in the control unit 1000 of the first embodiment shown in FIG. 9 .
[0185] Thus the fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine enables finding F1 gain required for stable combustion for combustion air humidity, which varies every moment, in the same manner as in the first embodiment and further evaluating humidity of combustion air, which flows into the gas turbine combustor, with high accuracy, thereby enabling realizing a highly reliable operation, in which a low NOx and stable combustion are made further exactly compatible with each other.
[0186] In the embodiment, intake spraying is started in the intake spray device 23 after humidification is made constant in the humidifier 4 as shown in FIG. 15 , but humidification can be started in the humidifier 4 after intake spraying is started to make intake spraying water quantity constant. Even in this case, the same fuel flow control method of the gas turbine combustor as that in the embodiment is applicable. In summer, in which atmospheric temperature rises, reduction in compressive power owing to intake spraying is especially effective.
[0187] Thus, according to the embodiment, a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine, which are capable of operation in high reliability before humidification, before and after the starting of humidification, and during humidification without damage in combustion stability and of maintaining a NOx yield in low level irrespective of a humidified condition, can be realized in a humid air gas turbine for humidification of air with the use of a spray type humidifier.
Embodiment 4
[0188] Subsequently, a fuel flow control method and a fuel flow control system of a gas turbine combustor, according to a fourth embodiment of the invention, provided in a humid air gas turbine will be described with reference to FIGS. 19 to 21 .
[0189] Since a fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine is common in fundamental constitution to the fuel flow control system of the gas turbine combustor of the third embodiment provided in a humid air gas turbine and shown in FIGS. 14 to 18 , descriptions of the constitution and function common to the both are omitted and a different portion will be described below.
[0190] FIG. 19 is a characteristics graph showing an example of the operating method of the humid air gas turbine according to the fourth embodiment of the invention, the characteristics graph of FIG. 19 corresponding to the characteristics graph of FIG. 15 in the third embodiment. The humid air gas turbine according to the embodiment is the same in constitution as that of the humid air gas turbine, according to the third embodiment, shown in FIG. 14 .
[0191] A difference between the fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine and the fuel flow control system of the gas turbine combustor of the third embodiment of the invention provided in a humid air gas turbine resides in that humidifier outlet humidity in a humidifier 4 is not evaluated directly in the same manner as in the second embodiment of the invention, but humidifier outlet vapor quantity G vh, exit in the humidifier 4 is first found and combustion air humidity is calculated from the humidifier outlet vapor quantity G vh, exit thus found.
[0192] In the operating method of the humid air gas turbine according to the embodiment, humidifier outlet humidity Hm h, exit in the humidifier 4 is evaluated with high accuracy by evaluating combustion air humidity from humidifier outlet vapor quantity G vh, exit in the same manner as in the second embodiment of the invention.
[0193] FIG. 20 is a schematic diagram showing the relationship between humidifier spray water quantity G wh, sp and humidifier outlet vapor quantity G vh, exit in the humidifier 4 in a humid air gas turbine system provided with the gas turbine combustor of the embodiment.
[0194] The characteristics graph of FIG. 20 shows a curve, along which humidifier outlet vapor quantity G vh, exit comes close to humidifier outlet maximum vapor quantity G vh, max when humidifier spray water quantity G wh, sp increases.
[0195] In the schematic diagram of FIG. 20 , humidifier outlet vapor quantity G vh, exit indicated by a dotted line is humidifier outlet vapor quantity G vh, exit in the case where intake spraying cooling is carried out, and humidifier outlet vapor quantity G vh, exit indicated by a solid line is humidifier outlet vapor quantity G vh, exit in the case where intake spraying cooling is not carried out, the schematic diagram corresponding to FIG. 12 related to the second embodiment of the invention.
[0196] In the operating method of the humid air gas turbine according to the embodiment, when humidifier spray water quantity G wh, sp increases, humidifier outlet vapor quantity G vh, exit comes close to humidifier outlet maximum vapor quantity G vh, max in the same manner as in the second embodiment of the invention. Under an ideal condition, humidifier outlet maximum vapor quantity G vh, max makes saturated vapor quantity G vh, sat relative to humidifier outlet flow rate of the humidifier 4 and outlet temperature 500 of the humidifier 4 .
[0197] In the operating method of the humid air gas turbine of the embodiment, in the same manner as in the third embodiment of the invention, unhumidified high temperature air 103 is humidified by the intake spray device 23 , so that when humidifier spray water quantity G wh, sp for the humidifier 4 is zero, humidifier outlet vapor quantity G vh, exit in the humidifier 4 is not made zero as indicated by the dotted line in FIG. 20 .
[0198] That is, when humidifier spray water quantity G wh, sp =0, humidifier outlet vapor quantity G vh, exit is equal to compressor outlet vapor quantity G vc, exit .
[0199] Here, compressor outlet vapor quantity G vc, exit is vapor quantity given by humidification from an intake part of the compressor 1 , in which the intake spray device 23 is included, to a discharge part of the compressor 1 .
[0200] For example, humidifier outlet vapor quantity G vh, exit is proportional to humidifier outlet maximum vapor quantity G vh, max and is given by a function proportional to a difference between a unit quantity and an exponential function value, of which a variable is given by a value obtained by multiplying the sum of humidifier spray water quantity G wh, sp and humidifier spray water quantity corrected quantity G wh, sp — cor by a minus proportional constant. Specifically, the relationship between humidifier spray water quantity G wh, sp and humidifier outlet vapor quantity G vh, exit is represented by the formula (2).
[0000] G vh, exit =G vh, max (1−exp(− C ·( G wh, sp +G wh, sp — cor ))) (2)
[0201] Here, C is a constant and G wh, sp — cor is a correction term taking account of humidification in the intake spray device 23 . That is, humidifier spray water quantity required for realizing humidification corresponding to compressor outlet vapor quantity G vc, exit in the humidifier 4 is humidifier spray water quantity corrected quantity G wh, sp — cor .
[0202] FIG. 21 shows an example of a concrete control block constituting the control unit 1000 in the fuel flow control system of the gas turbine combustor 2 of the embodiment provided in a humid air gas turbine.
[0203] A difference between the control unit 1000 of the fuel flow control system and the control unit of the fuel flow control system of the second embodiment resides in that in the present embodiment, a humidifier spray water quantity corrected quantity computing unit 400 calculates humidifier spray water quantity corrected quantity G wh, sp — cor from intake spray device spray water quantity G wc, wac sprayed from the intake spray device 23 .
[0204] A humidifier outlet vapor quantity computing unit 407 calculates humidifier outlet vapor quantity G vh, exit from humidifier outlet maximum vapor quantity G vh, max calculated by a humidifier outlet maximum vapor quantity computing unit 409 , into which humidifier outlet temperature 500 is input, humidifier spray water quantity G wh, sp sprayed in the humidifier 4 , and humidifier spray water quantity corrected quantity G wh, sp — cor calculated by the humidifier spray water quantity corrected quantity computing unit 400 , and the humidifier outlet vapor quantity G vh, exit calculated by the humidifier outlet vapor quantity computing unit 407 is input into a humidifier outlet humidity computing unit 404 for calculation of humidifier outlet humidity Hm h, exit .
[0205] Thus combustion air humidity can be evaluated with a higher accuracy even in a humid air gas turbine system provided with the intake spray device 23 by using the humidifier outlet vapor quantity computing unit 407 to calculate humidifier outlet maximum vapor quantity G vh, max taking account of not only humidifier outlet maximum vapor quantity G vh, max and humidifier spray water quantity G wh, sp but also humidifier spray water quantity corrected quantity G wh, sp — cor based on intake spray device spray water quantity G wc, wac . The remaining constitution of the control block is the same as that of the control unit 1000 of the second embodiment shown in FIG. 13 .
[0206] Thus the fuel flow control system of the gas turbine combustor of the embodiment provided in a humid air gas turbine enables finding F1 gain required for stable combustion for combustion air humidity, which varies every moment, in the same manner as in the first embodiment and further evaluating humidity of combustion air, which flows into the gas turbine combustor, with high accuracy, thereby enabling realizing a highly reliable operation, in which a low NOx and stable combustion are made further exactly compatible with each other.
[0207] Accordingly, according to the embodiment, a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine, which are capable of operation in high reliability before humidification, before and after the starting of humidification, and during humidification without damage in combustion stability and of maintaining a NOx yield in low level irrespective of a humidified condition, can be realized in a humid air gas turbine for humidification of air with the use of a spray type humidifier.
[0208] The invention is applicable to a fuel flow control method and a fuel flow control system of a gas turbine combustor provided in a humid air gas turbine, which makes use of highly humid air.
[0209] It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims. | Provided is a fuel flow control method of a gas turbine combustor provided in a humid air gas turbine, by which method NOx generation in the gas turbine combustor is restricted before and after the starting of humidification and combustion stability is made excellent.
The fuel flow control method of a gas turbine combustor provided with a plurality of combustion sections, to which a fuel is individually supplied, a part of the gas turbine combustor comprising a combustion section or sections, which are more excellent in flame holding performance than the remaining part, the method comprising evaluating a moisture content of a combustion air at the startup of humidification on the basis of a humidification water quantity and an air temperature after humidification and controlling a fuel ratio supplied to the combustion section or sections of excellent flame holding performance when fuel ratios of fuels supplied to the respective combustion sections are controlled in accordance with a humidified state of a compressed air brought about by a humidifier provided in the humid air gas turbine. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to dialysis and dialyzer apparatus. It relates to a dialysis system including a dialyzer. This invention is particularly directed toward the use of dialysis in medical diagnostic activity, in which it is desired to separate from a sample molecules of less than a given predetermined size by having them dialyze through a membrane into a surrounding bath. The invention is particularly adapted to use in clinical medical laboratories in which factors of speed, accuracy, and costs are important.
2. Prior Art
Dialysis is a known technique, including its use in the field of medical diagnostics. Prior art apparatus is known. Some of this prior art apparatus is relatively expensive and large automatic machinery. Some of the prior expedients include the suspension of relatively large elongated tubes of membrane from one end in an agitated bath with the tubes free to move relatively to each other.
Another prior art expedient is a dialysis bag clamping system utilizing a magnetic stirrer and having the capability of providing only for a limited number of dialysis bags. Such a device is known as the Crowe-Englander dialyzer available from Hoefer Scientific Instruments, Inc.
Other prior art is exemplified in such U.S. Pat. Nos. as 3,672,509; 2,985,587; 3,788,471; 3,503,877; 3,783,127; 3,811,573; and 3,596,882.
The present invention has many advantages over what can be found in any example of the prior art. These advantages include lower costs and higher speed in its class of equipment. An advantage is easy adjustability to accommodate different quantities of samples to be analyzed. An advantage is that wetted bags can be mounted in the operative position before loading. This permits accurate loading and unloading without handling of the bags and possible contamination or loss of sample. Other advantages include prevention of distortion of results by inadvertent contacting of bags during the dialysis process, the ability to make interim checks on the process, and the ability to determine whether there has been any inadvertent loss by leakage during the process.
Another advantage is the increased temperature stability due to the organization of the present dialysis system. Another advantage is a much greater speed of the dialysis process due to the greater efficiency of membrane surface circulation and a higher ratio of membrane surface to specimen volume than was heretofore available. An advantage lies in the provision of the circulating function through extremely simple, reliable, and inexpensive means. Other advantages are discussed in the following specification and will be apparent to those skilled in the art.
SUMMARY OF THE INVENTION
This invention is a small, fast, reliable, accurate dialyzer particularly suitable for non-automated, relatively small scale diagnostic analysis. The dialyzer system includes a container for a bath, generally distilled water, the dialyzer itself, and a motor and connecting means from the motor to the dialyzer, with the motor mounted above and isolated from the bath so as to avoid affecting the temperature stability of the bath.
The dialyzer itself generally comprises a central shaft on which are mounted an upper clamp unit and a lower clamp unit. The distance between the clamp units is adjustable to accommodate dialysis bags of different lengths. The entire periphery of the clamp units may be surrounded with an array of vertically oriented dialysis bags. In the preferred embodiment, there are twelve such bags, three on each side of the square clamp units.
The lower clamp unit has clamping bars to secure the bottoms of the dialysis bags and seal them. The lower clamp unit also is provided with a pair of oppositely slanted holes which together form a simple, elegant circulating pumping means to provide forced circulation of the bath into the central core of the dialyzer, that is, into that volume of the bath bounded by the vertical curtain of dialyzer bags.
The upper clamp unit is provided with a plurality of vertically aligned grooves or channels, with one channel corresponding to each bag. The upper portion of each bag is passed through its channel. A rigid filling tube is inserted in the upper portion of each bag, positioned within the channel. The filling tube extends above the end of the bag and the upper clamp unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation view, partly in cross-section of the dialyzer.
FIG. 2 is a perspective view of the dialyzer, showing one dialysis membrane bag in place.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2, partly fragmented and broken away in the middle section to show the top and bottom portions.
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The dialyzer can best be initially described in connection with FIG. 2. The dialyzer, generally designated 1, comprises means for supporting a plurality of membraneous dialysis bags for movement relative to an external bath. In comprises a central shaft 2. An upper clamp unit, generally designated 3, and a lower clamp unit generally designated 4, are provided. The upper clamp unit comprises an upper clamp central block 7. This central block is provided with a hole through the center thereof, and has a collar 5 surrounding the hole. A set screw 6 is provided through an appropriately threaded hole in the collar 5. The central block 7 may thus be selectively firmly positioned at any point along central shaft 2 by tightening the set screw 6. The central block 7 is square in its horizontal shape. Along each of the four sides of the square there is provided an upper clamp bar 8. Each of the upper clamp bars 8 is retained on the central block 7 by a pair of clamp bolts 9.
Each of the bars 8 has an inner face which opposes an outer face of the control block 7. The inner face of each bar 8 is provided with three vertically aligned substantially semi-circular grooves or channels 10. The opposing outer face of the control block 7 is provided with opposing, matching and aligned vertically aligned substantially semi-circular channels or grooves. The preferable number of such grooves on each clamping bar 8 and hence on each of the four sides of the central block 7 is three. It is apparent that each channel 10 and its opposing channel, together form an approximately circular vertical channel.
The lower clamp unit 4 comprises a lower clamp central block 15. The central block 15 is square in its horizontal configuration and its outer dimensions and configuration are the same as that of upper central block 7. As is better shown in FIG. 1, the lower clamp central block 15 is provided with a hole through the center thereof. The hole is surrounded by a collar 5. In the same manner as has been described in connection with the collar 5 on central block 7, the lower clamp central block 15's collar 5 is provided with a set screw so that the lower clamp unit 4 may be selectively moved along shaft 2 when the set screw is loosened, and firmly fastened in place when the set screw is tightened.
The lower clamp unit 4 is provided with four lower clamp bars 30. Each of these lower clamp bars 30 is opposed to one of the four sides or outer faces of the lower clamp block 15. Each of the bars 30 is retained against its opposing outer face or edge of the central block 15 by a pair of clamp bolts 9. The organization of the lower clamp bars and lower clamp block is the same as the organization of the upper clamp bars and the upper clamp block. The differences in structure between the upper clamp unit and the lower clamp unit 4 are as follows. The lower clamp unit 4 does not have the plurality of vertically aligned grooves or channels. Instead, the inner faces of the lower clamp bars 30 and the corresponding and opposing outer faces of the lower clamp central block 15 are flat. The lower clamp central block does however have structure that is not found in the upper clamp block. This structure is a pair of inclined openings 16, each running from the upper face to the lower face of the lower clamp central block 15. As best shown in FIG. 2, these two inclined openings are mounted on diametrically opposed sides of the central shaft 2, and their slants or inclination from the vertical, are in opposite directions from each other. Together, these inclined openings, organized as shown and described, comprise a pump. The two sections of inclined openings 16 amount to the equivalent of a section of a screw pump, that is, a pump utilizing the Archimedes Principle.
The upper clamp unit 3 and the lower clamp unit 4 are affixed on the shaft 2, spaced apart from each other with their sides aligned with each other. For better illustration, only a single dialysis bag 17 is shown retained in the dialyzer 1 by being clamped between the upper clamp central block 7 and the lower clamp central block 15. The bag 17 is vertically aligned, and at the upper clamp, it passes through the groove or channel 10. It is apparent that the dialyzer can accommodate twelve such bags 17, each positioned in one of the illustrated grooves 10. A more detailed description of certain aspects of the upper clamp unit, the lower clamp unit and the dialysis bag is better made below in connection with FIGS. 3, 4, and 5.
The complete structure making up an operating dialysis apparatus is best described in connection with FIG. 1. The dialyzer 10 is shown suspended in a container 22. This container is deeper than the distance between the upper and lower clamp units. Some of the bags 17 are shown installed. The central shaft 2 is extended upwards to a chuck 19. This connects the dialyzer 1 with a drive shaft 20. In the preferred embodiment, the drive shaft 20 runs to a right angle drive 31, which in turn is driven by a motor 21. The motor 21 is held in position by being clamped to a stand (not shown), or by being positioned as shown in any conventional manner. The motor is operated so that the dialyzer 1 is rotated in a clockwise direction, in the particular embodiment shown. In this mode of rotation, the inclined openings 16 pump liquid from the lower portion of liquid contained in the container 22 into the volume generally defined as between the plane of the dialysis bag 17 and the central shaft 2, and between the upper and lower central blocks. It is apparent that this pumped liquid may flow out again into the general volume of container 22 between the bags 17, and this is desired, since the purpose of the pump means 16 is to provide circulation.
In FIG. 1, the dialyzer is shown in its operating condition. For better illustration, the presence of the water in container 22 has not been shown. The water level is at least as high as the upper clamped portion of the dialysis bags 17. The water level is lower than the upper edge of filling tubes 18. All twelve dialysis bags 17 are in place in the showing of FIG. 1. As is more fully described below, the dialyzer 1 is rotated by means of motor 21, the pumping action circulates the surrounding water and the dialysis takes place.
FIG. 3 shows in more detail the upper and lower clamping elements in cooperation with the bag and other elements. Each clamp bolt 9 is provided with a threaded portion 11, as well as a conventional head. The head may be knurled and also may be provided with an internal socket to receive a hex wrench. Each upper clamp bar 8 and each lower clamp bar 30 is provided with a pair of holes, each to receive a clamp bolt 9. Corresponding openings are provided in the outer edges or faces of both the upper and lower clamp blocks. As best shown in FIG. 4, these bolt-receiving holes in the clamp blocks are each provided with a threaded metal insert 12. The threaded portion 11 of bolt 9 coacts with the threaded metal insert 12.
Each bolt is provided with a helical spring 13, as best shown in FIG. 4. One end of this bears against the outer face or edge of the appropriate clamp block 7 or 30. The other end of the spring 13 bears against the appropriate upper or lower bar 8 or 30. As shown in FIGS. 4 and 5, a recess is provided in the bar to accommodate the spring 13.
As best shown in the bottom portion of FIG. 3, the dialysis bag 17, which is an elongated tube open at both ends, extends between the lower clamp block 15 and the lower clamp bar 30. When the bolts 9 are tightened, the bottom of the dialysis bag 17 is closed and sealed by the clamping action.
The detailed structure of the interaction of the tube 17 and the upper clamp unit 3 is shown in the top portion of FIG. 3. As has been described, the bag 17 is vertically aligned with a channel 10. A small rigid tube 18 is provided, partly inside and partly outside dialysis bag 17, extending above the upper end of the dialysis bag. This rigid filling tube 18 extends through the extent of channel 10. It is apparent that when the upper clamp bar 8 is tightened against the upper clamp central block 7, the filling tube 18 is clamped tightly in the channel 10, inside the walls of the dialysis bag 17, and an opening into the bag 17 is maintained thereby. FIG. 3, in the top portion, additionally shows a filling, inflating, and exhausting means generally designated 24. It comprises a syringe 27 with a hypodermic needle 25. The size of the hypodermic needle is such that it may pass through the opening in filling tube 18. The hypodermic needle 25 is conventionally provided with a beveled tip 26.
Appropriate and preferred dimensions and materials are described. The tank 22 may be six inches in diameter with a height of 18 or 20 inches. Its capacity, full, is 6.5 liters. In practice it is filled with water to about 5 liters.
One satisfactory motor 21 is a Fisher Full Torque Motor obtainable from Fisher Scientific Company. This is a small fraction of a horsepower motor. The motor comes equipped with the right angle drive 31. It is provided with a variostat, that is, a potentiometer, to adjust the speed. The speed range of the driven central shaft 2 is on the order of 100 rpm. The motor is mounted on any type of conventional mount, for example, a laboratory clamp mount. The motor, the right angle drive, the speed varying means, and the coupling means, generally comprising an adjustable chuck 19, are all standard obtainable conventional items well known in the art.
In the dialyzer 1 itself, the central shaft 2, the springs 13 and the clamp bolts 9 are stainless steel. The other parts are transparent plastic, preferably methyl methacrylate. The edges of the clamping members are provided with small bevels or chamfers, not shown, to avoid damage to the delicate bags 17. As has been described, the bolt receiving holes in the central blocks are provided with threaded metal inserts. This is because it has been found preferable to have all moveable or adjustable parts be metal to metal to avoid undue wear. For the same reason, it has been found preferable to provide the spring-containing recesses in the bars, as have been described, with metal liners or sockets, to avoid wear on the plastic.
The rigid filling tube 18 is transparent plastic. It has an ID equivalent to a 28 gage needle. Such tubing is conventionally available and is known as micromedic tubing. The syringe 27 may be a standard syringe of 5cc capacity and the needle 25 attached thereto is an 18 gage needle.
The dialysis bags 17 are semi-permeable membranes, made of cellulose. The thickness of the bag membrane is generally less than 1/1000ths of an inch. The diameter of the bags is on the order of 1/4 of an inch. The membranes have fixed pore characteristics which act as a molecular sieve. They are commercially available from a number of suppliers and are well known in the art. They normally come commercially in the form of rolls of tubing, supplied dry, to be cut to length by the user.
The container 22 is preferably of transparent glass.
The shaft 2 may be 18 inches long and 1/4 inch in diameter. Each central block may have a horizontal side dimension of three inches, and a thickness of 1/2 inch. Each clamping bar may have a length of 23/8 inches and a horizontal thickness of 1/4 inch, with the height being the same as the width of the central block. Each channel 10 may have a diameter on the order of 1/16 of an inch.
The preferred rotational speed of the dialyzer is 90-100 rpm. Below this speed range, there is an increasing length of time required for satisfactory dialysis to take place. It has been found that 60 rpm should be considered the practical lower limit of rotational speed to avoid excessively long processing times. It has been found that above about 100 rpm, there is a relatively small gain in dialysis speed, with a continually greater risk of damage to the bags because of the increased stress on them. Therefore, 100 rpm is the preferred upper limit of rotational speed. The preferred operation has been described. The distance between the upper and lower clamp units is set to the desired length, depending on the volume of liquid to be dialyzed. The set screws 6 are then tightened to hold the clamp units at that length. Up to twelve pieces of dialysis bag 17 are cut from the roll, each to the desired length. They are then wet and the bottom of each bag is clamped in the lower clamp unit 4 as has been described. Then, a filling tube 18 is inserted into the top of each bag, which is aligned in its appropriate channel 10. As has been described, three bags are provided on each side of the blocks. The upper clamp bolts 9 are then tightened as has been described.
It is customary procedure to test the integrity of the bags and seals by partly inflating each bag. This is done either by mouth blowing into each tube 18, or the syringe and hypodermic needle means as illustrated in FIG. 3 may be used. A 5cc syringe and an 18 gage needle is provided, with the syringe being filled with air. The syringe is depressed to force air into the bag and inflate it, thus carrying out the test.
The dialyzer 1 is now mounted in the chuck 19. The liquid samples to be analyzed are then individually "injected" through the ends of the tubes 18 into the interior of the respective bags 16, using a filling means 24, comprising a syringe and needle. No further sealing is necessary. The appropriate level of water to cover the operating surface of the bag 17 is provided in container 22, and maintained at the appropriate temperature. The time and temperature characteristics of the dialysis process itself are well known in the dialysis art, and are not per se the subject of the present invention.
Depending on the type of analysis being performed, within the known art, the temperature conditions may be very important and the run may be conducted in a refrigerated environment.
A typical program would be four runs of thirty minutes each, with a change of water after each run, followed a three hour run. During the three hour run, instead of water, specific ions are placed in the liquid in container 22 and a reverse dialysis is accomplished, for the purpose of obtaining ionic equilibrium inside and outside of the bag. This technique in the art of dialysis, considered theoretically, is well known in the art, and has been accomplished by other known apparatus, and is not in itself the subject of this invention.
When the entire dialysis process is complete, a exhausting means 24 is utilized. This is exactly as illustrated in FIG. 3, except that the needle 25 is longer, on the order of 15 inches long, so that it can reach down to the bottom of the bag. The contents of the bag can then be withdrawn by raising the plunger of the syringe.
An alternate way to empty the bag 17 after the dialysis is completed, is to open the bottom clamp and permit the contents of the bags to drain.
If the syringe method of removal is used, it is possible then to flush the interior of the bag and reuse it for another specimen. It is also possible to remove all or a portion of the specimen from the bag, using the syringe method, for an interim test and then to replace it for further processing if desired.
It is understood that the use of stainless steel, glass, and methyl methacrylate are preferable, as described, because they do not leach any contaminants into the bath. It is also apparent that other materials having the necessary chemical and physical properties, as known, may be utilized.
No contribution to the theory of dialysis itself is intended as part of this present invention, and it is apparent that the method and apparatus of this present invention are applicable to all appropriate operations utilizing the known theories and techniques of dialysis. Some observations are made however, to more particularly indicate the uses of the present invention. The liquid inserted in the bag to be analyzed is a mixture of different size molecules. The membrane has given pore sizes. Generally and normally distilled water is used outside of the bags, within the container, as a bath. Molecules having a diameter smaller than the pore diameter of the membrane migrate through to the bath until there is an equality of concentration of molecules of this size on both sides of the membrane, at which time the system comes to equilibrium. Then, when the outside bath water is changed, there is a further migration as aforesaid. The process can be repeated until the amount of moelcules under a given diameter in the sample can be reduced to almost any desired amount, approaching zero.
Then, the contents of the dialysis bag, which are known to contain only molecules of a certain size or larger, are subjected to further and other analytical procedures which are not part of this invention. For example, they may be subjected to electrofluorisis.
One example of the use of this invention arises when amonium sulphate is used to precipitate long chain protein molecules from macerated tissue specimens. It is necessary to get the amonium sulphate out of the specimen, because otherwise the later analytical procedures would be misled by the amonium sulphate. The dialysis process, carried out in accord with this invention, removes the amonium sulphate ions from the specimen.
Another example of the use of this invention is in blood analysis. Blood specimen cells are ruptured sonicly. Then, by dialysis, salts, fibrinogen, and in general all the smaller size molecules (which generally means lower molecular weight molecules) are removed from the specimen, leaving only the macro-molecules. For some purposes this is a very valuable analytical step. On important analytical end purpose in blood analysis is to detect the presence of C.E.A. (Carcinoembryonic Antigen). It has been found that the presence of C.E.A. can be diagnostic of cancer in a patient. Another purpose is for isolating materials useful for preparation of immunological materials.
There are a number of advantages in the present invention. These are discussed below, perhaps not exhaustively. This invention contemplates and permits the simultaneous processing of up to twelve separate dialysis bags. Perhaps more than the actual number, the advantage lies in the use of the entire periphery of the central blocks to support dialysis bags. The productive capacity of a unit of this physical size is thus greatly increased.
It has been found previously not practical to simply add on bags around the periphery as is done in this invention, because the addition of bags simultaneously serves to cut down free circulation of the bath, usually distilled water, and thus, the apparent increase in productive capacity is offset by less efficient dialysis and therefore longer processing times. The elegant and simple expedient of providing the slanted openings 16 in the bottom central block 15, as has been described, overcomes the circulation problem. As has been explained, the pair of openings serve as a circulating pump and force the bath liquid into that sector which would otherwise tend to be relatively stagnant. It has been found that this moves the central core volume of water sufficiently to permit the closed "curtain wall" of bags to be provided around the periphery.
The use of set screw mountings on the collars of the upper and lower blocks 7 and 15 permit the use of different lengths of bags. Thus, it is apparent that the availability of different bag lengths and different numbers of bags in a given run provide a great deal of flexibility in application.
Another important advantage is that the wetted bags can be mounted on the dialyzer before they are loaded with the material to be analyzed. In previously known devices, it was necessary to load the bags before they were fully secured to the dialyzer. Such prior art procedures had a potential for spillage of the sample. The present invention removes this potential. In the present invention, all the bags to be used are firmly clamped at both top and bottom before it becomes necessary to load them with sample to be analyzed.
The use of the spring loaded clamps, as described, permits insertion and removal of bags in a dialyzer without complete physical removal of the clamp from the unit as a whole. That is, when the bolts 9 are loosened, the springs force the bars away from the central blocks to permit easy insertion or removal of the portions of the bag to be clamped.
Another advantage of the present invention over certain other prior art is that the present structure permits the motor to be mounted above the tank and isolated from it. This removes the possibility of heat transfer from the motor to the tank. In some prior art devices, the motor is mounted below the tank and drives the dialyzer support through a magnetic coupling. For long runs, particularly where temperature stability is important or where there is a refrigerated enviornment necessary, this unwanted heat is detrimental. This problem is obviated by the present invention.
Another important advantage lies in the fact that the time for each run and the total running time for a full processing are very substantially less in this invention's use than with some prior art expedients. For example, a more common dialysis method and apparatus involves tubing of perhaps an inch in diameter and quite long, tied at each end manually and hung from a string in a tank with agitated water. From time to time the water is flushed. This type of dialysis may take perhaps forty-eight hours to produce results. On the other hand, with the present invention, overall equivalent processing times, including multiple runs, may be on the order of five hours. Some of the reasons for this improvement are the ability of the present invention to use smaller diameter dialysis bags, thus bringing more of the sample in contact with the membrane. The use of the multiple bags and the ease of loading them makes up for the loss of volume introduced by decreasing the bag diameter. Another reason is the efficient circulation enviornment provided by the present invention. Thus, the present invention is very fast, efficient and reliable. Another advantage is that this entire apparatus is very much cheaper than many of the prior art machines commercially available.
Another advantage is that there is much less potential for contaminating the specimens with the present invention than with some of the prior art devices. It is apparent that being able to handle the specimen entirely with syringes, both to load and unload, and the ease of handling the bags after they are firmly fixed in place, all contribute to this advantage. Furthermore, in many of the prior art devices, where the bags are suspended only at one end, they inadvertently touch each other at times through the cycle and thus inhibit the dialysis process and tend to produce false results. This type of problem is actually a common one in presently available prior art.
The use of the syringe loading and unloading in the present invention produces another advantage. This arises because such syringes are commonly calibrated, and it is thus possible, without introducing any significant extra step, to measure the amount of specimen in, compare it with the amount of specimen out, and determine whether there may have been any loss.
The scope of the invention is determined by the appended claims and is not intended to be limited by the specific embodiment shown and described. | A dialyzer and a dialysis system particularly adapted to fast dialysis and avoidance of contamination or spillage. Adjustable upper and lower clamp units are provided on a central shaft. Means are provided to securely mount a plurality of dialysis bags around the entire periphery of the clamping units and to provide adequate bath circulation through the relatively confined core volume. The individual dialysis bag may be accurately filled or emptied while in a fully installed position on the dialyzer. The circulating pump is a pair of openings in the bottom clamp unit. The top of each bag is always open to receive a syringe needle. The rotating motor is isolated from the bath. | 1 |
TECHNICAL FIELD
[0001] This disclosure relates to the field of automotive transmission hydraulic control systems. More particularly, the disclosure pertains to a hydraulic control system having an auxiliary sump.
BACKGROUND
[0002] Many automotive transmissions utilize pressurized lubrication. A pump draws fluid from a sump and forces the fluid through lubrication passageways in gearbox components. The lubrication passageways are carefully designed to ensure that fluid reaches all of the parts that require lubrication. The fluid is then discharged from the gearbox components by a combination of gravitational forces and centrifugal forces generated by rotating components. Eventually, the fluid flows back to the sump which is located at the lowest point in the transmission housing. A sufficient quantity of fluid must be present to ensure that the sump does not become empty. The quantity required is typically dictated by cold operating conditions because the fluid has much higher viscosity when cold and therefore takes longer to drain back to the sump.
[0003] If the fluid level in the sump is high, some of the rotating components of the gearbox may extend into the fluid. When that happens, the fluid resists the movement of the components. The engine must generate additional torque to overcome the additional parasitic drag, increasing fuel consumption. Furthermore, the churning that results when rotating components move through the fluid may result in small air bubbles forming in the oil. These air bubbles make the fluid less effective. Excessively high fluid level is most likely to occur at higher temperature because the fluid drains back to the sump quickly so a small fraction of the fluid is in transit.
SUMMARY OF THE DISCLOSURE
[0004] A transmission hydraulic control system includes a primary sump, an auxiliary sump, and an oil control valve. The oil control valve passively restricts flow from the auxiliary sump to the primary sump when the fluid temperature exceeds a threshold. The threshold varies depending upon whether the engine is running or not. Excess flow may be vented to the auxiliary sump. An engine driven pump draws fluid from the primary sump and pressurizes the fluid to a line pressure. The oil control valve may utilize line pressure as an indicator of whether or not the engine is running.
[0005] An oil control valve includes a housing and first and second sliding spools. The housing defines four ports, one connected to line pressure, one connected to the auxiliary sump, and one connected to the primary sump. A wax motor separates the two spools by a distance that depends upon the temperature of fluid in the fourth port. The position of the first spool is determined by the line pressure which biases the spool toward the second spool. When the line pressure is above a threshold, the first spool may move against a shoulder of the housing. The shoulder may be created by using a smaller diameter for the second spool than for the first spool. The second spool is biased by a spring. The second spool is configured to permit flow between the auxiliary sump and primary sump in certain positions and to block the flow in other positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic representation of transmission hydraulic network.
[0007] FIG. 2 is a cross sectional view of an oil control valve when fluid is colder and an engine is off.
[0008] FIG. 3 is a cross sectional view of an oil control valve when fluid is colder and an engine is on.
[0009] FIG. 4 is a cross sectional view of an oil control valve when fluid is at moderate temperature and an engine is on.
[0010] FIG. 5 is a cross sectional view of an oil control valve when fluid is at moderate temperature and an engine is off.
[0011] FIG. 6 is a cross sectional view of an oil control valve when fluid is at normal operating temperature and an engine is off.
[0012] FIG. 7 is a cross sectional view of an oil control valve when fluid is at normal operating temperature and an engine is on.
DETAILED DESCRIPTION
[0013] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
[0014] A transmission hydraulic control system is illustrated schematically in FIG. 1 . Bold lines represent the flow of mechanical power. Solid lines represent the flow of hydraulic fluid. One solid line may represent multiple fluid circuits. Dotted lines represent control signals. Power is provided by engine 10 which drives the impeller of torque converter 12 . Torque converter 12 transmits torque from an impeller to a turbine whenever the impeller rotates faster than the turbine. This is beneficial when the vehicle must accelerate from a stationary condition. To transmit torque, torque converter 12 must be filled with fluid. Torque converter 12 may also include a bypass clutch that, when engaged, transmits power from the impeller to the turbine without requiring a speed difference. The bypass clutch may be engaged by providing pressurized fluid. The fluid for these functions is provided by valve body 14 via fluid circuits 16 . The turbine of torque converter 12 is fixed to the input shaft of gearbox 18 . Gearbox 18 establishes various speed ratios based on current driving conditions. At low vehicle speeds and high torque demands, gearbox 18 multiplies the torque and reduces the speed. For cruising, gearbox 18 multiplies the speed such that the engine can operate at a low speed that is quiet and efficient. The gearbox speed ratio may be established by providing pressurized fluid to a subset of clutches via fluid circuits 20 . Fluid may flow in either direction through circuits 16 and 20 . Additionally, fluid flows at relatively low pressure through lubrication circuit 22 to gearbox 18 and then returns to primary sump 24 . Fluid return flow path 26 represents the interior of the transmission housing. Primary sump 24 is located at the lowest point in the housing such that gravity causes the fluid to return to the sump.
[0015] Pressurized fluid is provided by pump 28 , which draws fluid from primary sump 24 and transmits the fluid to valve body 14 via line pressure circuit 30 . The power required to pressurize the fluid comes from engine 10 . Whenever the pressure in line pressure circuit 30 exceeds a desired value, regulator valve 32 diverts some flow to auxiliary sump 34 via circuit 36 to relieve the excess pressure. Valve body may also exhaust excess fluid to auxiliary sump 34 via circuit 38 . Auxiliary sump 34 is located higher than primary sump 24 and is located such that the rotating components of gearbox 18 do not move through any fluid that may be in auxiliary sump 34 . Storing fluid in auxiliary sump 34 reduces the volume of fluid in primary sump 24 . Ideally, the volume of fluid in auxiliary sump 34 is managed such that sufficient fluid remains in primary sump 24 yet the fluid level in primary sump 24 is lower than the lowest rotating components. To increase the volume of oil in primary sump 24 , oil control valve 40 opens to permit flow through circuits 42 and 44 . To decrease the volume of oil in primary sump 24 , oil control valve 40 closes such that fluid pumped out of primary sump 24 by pump 28 builds up in auxiliary sump 34 . When the volume of fluid in auxiliary sump 34 exceeds the sump capacity, it overflows and returns to primary sump 24 via the housing.
[0016] An oil control valve, like other types of valves, may be either passively controlled or actively controlled. When an actively controlled valve is utilized, a controller must determine the appropriate state of the valve based on sensors and then command the valve to open or close accordingly. For example, an actively controlled valve may be actuated by a solenoid that exerts a force in response to an electrical current regulated by the controller. In addition to the cost of the solenoid itself, active control increases costs because the controller must include a driver circuit to regulate the electrical current. A passively controlled valve, on the other hand, changes state from open to closed and from closed to open without a command from a controller.
[0017] The state of oil control valve 40 depends upon temperature control signal 46 and engine operation control signal 48 . Temperature control signal 46 indicates a representative temperature of the fluid. In FIG. 1 , temperature control signal 46 is implemented by routing circuit 36 through oil control valve 40 . Other circuits could be selected for this purpose as long as the temperature of fluid in the circuit is representative. Circuits that are segregated as the fluid changes temperature are less appropriate for this purpose. Also, circuits that may be evacuated some of the time should be avoided. Engine operation control signal 48 is implemented by exposing oil control valve 40 to line pressure circuit 30 . When the engine is not running, the pump does not rotate and the pressure in circuit 30 rapidly falls to near zero. When the engine is running, the pressure in circuit 30 is above a minimum line pressure threshold.
[0018] FIG. 2 shows a cross section of oil control valve 40 when the engine is not running and the transmission fluid is cold. Valve bore 60 defines a number of ports 62 , 64 , 66 , 68 , and 70 separated by a number of lands 72 , 74 , 76 , 78 , and 80 . Spool 82 slides axially between lands 76 , 78 , and 80 . The diameter of spool 82 is less in a central section than near the ends. Spring 84 pushes spool 82 toward the left. Wax motor 86 is inserted into spool 82 . Pin 88 emerges from wax motor 86 by a distance that depends upon the phase of wax. When the wax is in a solid state, as shown in FIG. 2 , pin 88 extends a small distance. When the wax is heated, it changes to a liquid state and pushes pin 88 out by a greater distance. Spool 90 , which has a larger diameter than spool 82 , slides axially under land 74 . Plug 92 is inserted under land 72 and held in place by plate 94 .
[0019] Port 62 is connected to line pressure circuit 30 which provides the engine operation control signal 48 . Since this signal would be generated regardless of whether the hydraulic circuit has an oil control valve, no additional solenoids are required. As shown in FIG. 2 , the engine is off so this circuit is not pressurized. Consequently, pin 88 pushes spool 90 to the left against plug 92 . Ports 64 and 70 are both connected to the regulator valve pressure relief circuit 36 which provides temperature control signal 46 . Heat transfer occurs between the fluid and wax motor 86 such that the temperature of the wax closely follows the temperature of the fluid. Since this circuit acts on both ends of spool 82 and the ends have nearly identical areas, the net force imposed is negligible. Port 66 is connected to auxiliary sump 34 via circuit 42 and port 68 is connected to the primary sump 24 via circuit 44 . In the position shown in FIG. 2 , the reduced diameter section of spool 82 is centered under land 78 providing a flow passage from port 66 to port 68 . Gravity forces fluid to flow from auxiliary sump 34 through oil control valve 40 to primary sump 24 .
[0020] FIG. 3 shows a cross section of oil control valve 40 when the engine is running and the transmission fluid is cold. When the engine is on, line pressure forces spool 90 to the right. Spool 90 forces spool 82 to the right compressing spring 84 . Movement to the right stops when spool 90 encounters shoulder 96 . In the position shown in FIG. 3 , fluid may still flow from port 66 to port 68 permitting auxiliary sump 34 to drain into primary sump 24 . Since the oil is still cold, this makes the entire volume of oil available ensuring adequate oil even if the oil drains back slowly from gearbox 18 .
[0021] FIGS. 4 and 5 show oil control valve 40 at an intermediate temperature when the engine is on and when the engine is off, respectively. At this temperature, flow is blocked when the engine is on as shown in FIG. 4 and flow is allowed when the engine is off as shown in FIG. 5 . This behavior is desired during final test of the transmission. After the transmission is assembled, it is placed on a test stand which performs a variety of test to ensure that all features are functioning properly. For example, the test stand would command various shifts to ensure that the speed ratio changed as commanded. To test that the oil control valve is functioning properly, the test much be of sufficient duration to heat the fluid enough to that the oil begins accumulating in the auxiliary sump. If the temperature at which that occurs is too high, then final test requires a long time. After the test, it is desirable to verify that the oil level is appropriate. Oil control valve 40 allows all of the oil to immediately drain to the primary sump following final test. If the oil control valve did not react to an engine running signal, it would be necessary to wait for the oil to cool down before verifying the oil level in the primary sump.
[0022] FIGS. 6 and 7 show oil control valve 40 at normal operating temperature when the engine is off and when the engine is on, respectively. At this temperature, flow is blocked independent of whether or not the engine is running. This behavior is desirable because some vehicle are programmed to reduce fuel consumption by stopping the engine while waiting at a traffic light and restarting the engine automatically when the driver releases the brake pedal. If the fluid drained from the auxiliary sump to the primary sump while the engine was off, then the transmission parasitic drag would be higher when the engine restarted.
[0023] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications. | A hydraulic control system includes a primary sump and an auxiliary sump. When the transmission fluid is warm, fluid remains in the auxiliary sump reducing the volume of oil in circulation throughout the transmission to reduce parasitic losses. An oil control valve is designed to block flow of oil from the auxiliary sump to the primary sump when the fluid is warm and to allow flow when the fluid is cold. The oil control valve also responds to transmission line pressure. At moderate temperatures, fluid is held in the auxiliary sump when the engine is running but drains back to the primary sump when the engine is off. | 5 |
The invention herein described was made in the course of or under contract with the Naval Research Laboratory, U.S. Department of the Navy, contract number N00014-87-C-2516, sub-contract number 200-14-14P94023.
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of contract No. N00014-87-C-2516.
FIELD OF THE INVENTION
This invention relates to the coating of fibers to make them more suitable for use in fiber-reinforced composites. More specifically, the invention concerns a process for coating reinforcing fibers, and apparatus for continuously coating such fibers.
BACKGROUND OF THE INVENTION
High-performance fibers are being increasingly used as the reinforcement of plastic, metal, ceramic, and carbon matrix composites. When the composite has a ceramic matrix, the main role of the fibers is to toughen the composite to prevent brittle failure. The degree of toughness attained is greatly affected by the bond strength between the fibers and matrix. If the bond strength is too high, cracks propagate through the fibers; if too low, the load is not transferred to them.
The most demanding of these applications are those involving high operating temperatures. In such environments, the matrix may chemically react with, or dissolve the fiber. Although chemical reaction may in some cases be beneficial, it usually leads to drastic reductions in strength and toughness. In many cases, these high-temperature problems can be solved by applying barrier coatings on the fibers by chemical vapor deposition (CVD). As the name implies, CVD involves the deposition of coatings onto substrates by chemical reaction from the vapor phase. The technique is widely known and a number of review articles exist on the subject. See, for example, Blocher, J. M., Jr., "Deposition Technologies for Films and Coatings", Noyes Publications, page 335-364 (1982). Blocher discusses the roles of thermodynamics in predicting the possibility of deposition with various reactants under given temperatures and reactant partial pressures, of kinetics on the rate of deposition, and of transport processes such as diffusion and heat transfer in CVD. This reference also describes the effects of these variables and their interactions on coating properties.
The application of a coating by CVD to a monofilament is a fairly simple procedure. See, for example, EPO Pat. Publ. No. 0,222,960 (Schachner) where a monofilament is drawn and coated by CVD in-line. When the monofilament is electrically conductive, it can be heated resistively during CVD, thereby activating the chemical deposition reaction primarily on the monofilament and not in the gas phase or on the unheated wall of the tube that confines the gaseous mixture. There is a considerable amount of art describing such "cold wall" deposition systems by which CVD coatings are applied to monofilaments by continuous processes. See, for example, U.S. Pat. Nos. 3,549,424 and 4,068,037.
When coating by CVD a fiber that has multiplicity of filaments, e.g., a tow, it is necessary no diffuse the reactant(s) between the filaments. A translation of French Patent No. 2,607,840 states that:
"This vapor phase deposition, designated by the American acronym CVD, does not allow one to obtain good protection for all of the individual filaments that constitute the tow of carbon. Actually it is very difficult, if not impossible, to avoid preferential deposition, particularly in the peripheral zones of the tow, and equally, to avoid the cementing together of the filaments. These drawbacks make the process unsuitable for industrial utilization. In other words, the CVD technique, even though very attractive in theory, does not allow the control of coating thickness and homogeneity of the carbide deposit specially when, as is the case in a tow, the gaseous reaction medium diffuses poorly into the center. It follows that the individual filaments of carbon are not coated homogeneously, regularly, and with controlled thickness."
To alleviate the difficulties mentioned in the French patent, it is common to coat multiple-filament fibers by CVD at low pressures (LPCVD). This increases the mean free path of the reactants, thereby decreasing homogeneous nucleation and the growth of soot particles in the gas phase. It also facilitates the diffusion of the gases between the filaments, thus reducing the variability in coating thickness. However, such a reduced pressure coating process requires building and maintaining of sophisticated, expensive equipment. See U.S. Pat. No. 4,343,836 (Newkirk et al.) In many cases, such equipment is limited to batch processes. See, for example, U.S. Pat. No. 3,212,926 (Morelock) and U.S. Pat. No. 4,214,037 (Galasso et al.), the latter of which suggests that similar coating results can be obtained in a continuous process.
Difficulties are encountered when LPCVD processes for coating a multi-filament fiber are made continuous. Deposits on the inner wall of the coating chamber gradually diminish its volume and eventually require it to be replaced. Fuzz (tangles of broken off filaments) and soot (homogeneously nucleated and grown particles) that form in the system during coating interfere with fiber movement. To prevent fiber breakage, the fuzz and soot must be periodically removed. When cleaning is required or when the fiber breaks during the coating process, the vacuum has to be broken, and after repair the system has to be pumped down. If the coating is performed at high temperatures, partial cool-down and subsequent reheating of the coating system is also required.
These difficulties demonstrate a need for a system by which a multi-filament fiber can be continuously coated by CVD at atmospheric pressure (APCVD), and such systems have been reported. See, for example, Honjo et al., Composite Interfaces, Proc. Int. Conf. 1st, pp. 101-107 [1986]; Aggour et al., Carbon, Vol. 12, pp. 358-362 [1974]; and Amateau, J. Compos. Mater., Vol. 10, pp. 279-296 [1976]). However, the apparatus illustrated in each of those publications would need to be disassembled to be cleaned and so would offer little advantage over a LPCVD system such as that shown in the Newkirk patent.
U.S. Pat. No. 4,373,006 (Galasso et al.) says that "even when upwards of 10,000 fibers are bundled together to form a strand of yarn the chemical vapor deposition of silicon carbide produces an essentially uniform coating of silicon carbide over the surface each fiber even on those fibers in the center of the yarn and even on those areas of fibers which are in close proximity to one another" (col. 2, lines 57-64). It also says that carbon fibers were coated with silicon carbide "by holding the fibers in a chamber . . . maintained at a temperature of between 1100° and 1200° C. by passing them through an R.F. heated graphite susceptor" (col. 3, lines 41-49). However, there is no disclosure of the nature of the fiber-handling apparatus and no drawing.
For a detailed discussion of the advantage of coating ceramic fibers with BN for use in composites, see U.S. Pat. No. 4,642,271 (Rice). However, coating conditions are not given. It is not even stated whether APCVD or LPCVD is used, and no apparatus is illustrated.
U.S. Pat. No. 4,731,298 (Shindo et al.) concerns coating carbon fibers first with a layer of carbon and then with a metal carbide. "The carbon fibers may be in the form of yarns, tows or webs of continuous filaments. The carbon fibers may be used in the form of yarn and webs of short fibers or the like" (col. 2, lines 65-68). However, no method is disclosed; neither is any apparatus disclosed.
SUMMARY OF THE INVENTION
The present invention provides what is believed to be the first apparatus by which barrier coatings can be continuously applied by CVD to a multiplicity of filaments or fibers such as a tow of filaments or a yarn or a strip of woven fabric. Such a multiplicity of filaments or fibers is sometimes hereinafter referred to as "the fibrous material."
Briefly, the novel coating apparatus includes a furnace,
a straight, elongated furnace tube extending through the furnace, which furnace tube is formed with
a uniform inside diameter of sufficiently large size to receive a tool for periodic cleaning while the apparatus is in use,
an unconstricted outlet,
an ambient atmosphere-excluding (preferably constricted) inlet through which said fibrous material enters, and
intake means for receiving a gaseous mixture comprising one or more reagents that can coat said fibrous material by CVD.
The apparatus permits a long length of inorganic fibrous material to be carried continuously through the gaseous mixture, the residue of which is freely exhausted through the unconstricted outlet. At the unconstricted outlet, back-diffusion of the air is kept at acceptable levels by the flux. The furnace tube can be fitted with liner that is easily replaced simply by pulling it through the outlet. This allows deposits of fuzz and soot to be periodically eliminated without interruption of the coating process and without disturbing either the inlet for the fibrous material or the intake means.
Preferably the novel coating apparatus is operated at atmospheric pressure, thus eliminating the need for the supply and takeup reels to be contiguous with the furnace tube and making it easier to remove a liner. The in-diffusion of air through the fiber inlet can be kept at acceptable levels by using a long small-diameter inlet tubing. When that inlet-tubing has a uniform, slot-like cross-sectional area, a plurality of tows, rovings or yarns can be carried side-by-side through the inlet tubing without crowding. A slot-like interior is also useful for coating strips of woven fabric.
The invention also provides a method of continuously applying CVD coatings onto a long moving length of inorganic fibrous material. The method comprises the steps of:
a. while excluding the atmosphere, continuously carrying the fibrous material lengthwise at atmospheric pressure through a heated gaseous mixture comprising one or more reagents that deposit CVD coatings,
b. freely exhausting the residue of the gaseous mixture along the path of the fibrous material in the direction of its movement,
c. maintaining the fibrous material within the gaseous mixture for a time to deposit a CVD coating onto the moving fibrous material, and
d. removing the coated fibrous material from the gaseous mixture.
To enhance the uniformity of the coating thickness distribution, one operates at low temperatures and low partial pressures of the reactants. These conditions favor surface reaction (heterogeneous growth) as opposed to reactions that involve ready nucleation and growth of particles in the gas phase (homogeneous reactions). Such conditions entail relatively low deposition rates and thus limit the speed at which the fibrous material may be pulled through the reactor while still attaining the desired coating thickness. There is thus a compromise between economics and coating thickness uniformity.
For identical deposition conditions, the coating thickness distribution is more uniform on tows than on fabrics, because the filaments are more constrained in the latter. Nevertheless, as will be demonstrated in Example 36, even in fabrics one can completely cover each filament with a CVD deposit.
When the CVD employs two reagents that react readily with each other and so should be separated until they are in position to be deposited on the fibrous material, there preferably is a separate intake for each of those reagents and an additional port between those two intakes for receiving inert gas. This keeps the reagents separated until they have been heated in the furnace tube to the deposition temperature.
For easy cleaning, the inner wall of the furnace tube preferably is cylindrical. To receive a cleaning tool without undue danger of damaging the fibrous material, the inside diameter of a cylindrical furnace tube or its liner preferably is not less than one cm, and more preferably its inside diameter is at least 2 cm. On the other hand, its inside diameter preferably does not exceed 5 cm, because substantially larger diameters may require a wasteful increase in flux. Instead of being cylindrical, tubes with different cross-sectional shapes, e.g., rectangular, may be used.
The length of the furnace tube preferably is from 25 to 50 cm. Substantially longer furnace tubes would make the removal of fuzz and soot difficult. In shorter furnace tubes, some CVD reactions may not yet have reached equilibrium at the outlet, and thus the maximum possible deposit may not yet have formed.
Fibrous materials that can be coated in the novel apparatus are inorganic and include ceramic, carbon, and other high-performance fibers. CVD barrier coatings that can be applied to fibrous materials in the novel apparatus include ceramics, carbon and metals.
Barrier-coated fibrous materials of the invention have utility in toughening inorganic and organic matrices derived from metals, ceramics, glasses, carbon, and polymers. The barrier coatings can improve wetting of the fibrous materials by the matrix, establish a favorable bond strength between the fibrous materials and matrix to further toughen the composite, prevent chemical reaction between fibrous materials and matrix, and prevent dissolution of the fibrous materials in the matrix.
A BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, each of which is schematic,
FIG. 1 is a side elevation of APCVD coating apparatus of the invention;
FIG. 2 is a perspective view of a cleaning tool that is useful in the apparatus of FIG. 1;
FIG. 3 is a perspective view of another useful cleaning tool;
FIG. 4 is a side elevation of equipment that can be substituted into the apparatus of FIG. 1;
FIG. 5 is a side elevation of another variation in the apparatus of FIG. 1;
FIG. 6 is a side elevation of equipment for either heat treating or applying a second APCVD coating in-line with the apparatus of FIGS. 1, 4 or 5;
FIG. 7a is a side elevation of additional equipment that can be substituted into the apparatus of FIG. 1;
FIG. 7b is a top view of the equipment of FIG. 7a;
FIG. 8 is a histogram of light transmission through mullite fibers that have received a SiC coating as described in Example 1;
FIG. 9 is a 100,000X TEM micrograph of a CVD coating produced according to Example 1;
FIG. 10 is a 390X SEM micrograph of CVD coatings after chemical removal of the filaments to which they had been applied; and
FIG. 11 shows the effect of undercoating with carbon and BN on bend strength of SiC-coated ceramic fibers.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a simple APCVD apparatus 10 that includes a cylindrical furnace 11 and a straight, elongated cylindrical quartz or mullite furnace tube 12 extending beyond the ends of the furnace. The furnace tube 12 has a uniform diameter throughout its length and is fitted with a cap 14 at its fiber-receiving inlet. Fitted into the cap is a long, cylindrical, small-diameter inlet tubing 16, and aligned with the inlet tubing is a supply roll 18 of a continuous tow 20. The inlet tubing 16 has a uniform inside diameter throughout its length and (except being flared outwardly at its entrance 22) is barely large enough to receive the tow. The furnace tube is unconstricted at its outlet 26. Upon exiting from the furnace tube, the tow 20 is drawn across a thread guide 23 and to a take-up roll 24.
The cap 14 is formed with a conduit 28 that serves as an intake for a gaseous mixture including a reagent. The cap also is formed with a second conduit 30 that serves as a port to feed a carrier gas such as argon into the furnace tube 12, which carrier gas may include additional reagent. The total flux, when subjected to the high temperature of the furnace 11, deposits a continuous coating by CVD onto the filaments of the moving tow 20. The flux exiting through the unconstricted outlet 26 should be sufficient to minimize the back diffusion of air such that non-oxide coatings can be attained with acceptable levels of oxygen contamination.
Deposition takes place not only on the tow 20 but also on the walls of the furnace tube 12. As the cross-sectional area of the furnace tube 12 gradually decreases, the tow rubs more-and-more against the deposit, causing breakage of ever increasing numbers of the filaments until finally the tow breaks entirely, necessitating replacement of the furnace tube. However, to maintain acceptable reproducibility in the properties of the coatings, reproducible gas flow characteristics must also be maintained. It is therefore desirable to change the furnace tube before it becomes clogged and the fibrous material breaks. To avoid having to reattach the inlets, a removable liner 58 may be used as shown in FIG. 4.
Depending on the fibrous material used and on the coating conditions (temperature, gas composition, contact with fuzz, and the deposit on the wall of the reactor), some filaments break off the tow and form a "fuzzball". Also accumulating in the furnace tube are soot particles that form by homogeneous nucleation and growth. Many of these soot particles are carried out by the flux, but others deposit on the wall of the furnace tube and on the fuzzball, densifying the latter. If left in the furnace tube, the fuzzball and soot deplete the gaseous reactants, become cemented together by CVD, and increasingly rub against the fibrous material. This causes breakage of additional filaments and eventually of the whole fibrous material. The elongated tools of FIGS. 2 and 3 are effective for removal of the fuzzballs and soot.
FIG. 2 shows an elongated tool 34 that can be used to clean the interior of the furnace tube 12. The cleaning tool 34 includes a long rod 35, to the end of which is fixed a semi-circular flange 36, the diameter of which is smaller than the inside diameter of the furnace tube. The flange 36 is semi-circular so that the tow 20 can continue to be drawn through the furnace tube while it is being cleaned. The cleaning tool 34 preferably is formed of fused silica.
Another useful cleaning tool 37, as shown in FIG. 3, is formed from a quartz rod to have a flag-shaped projection 38 which is advantageous to use when constriction of the cross-sectional area of the of the furnace tube (or its liner) precludes the use of the tool 34.
For more demanding reactions, the equipment shown in FIG. 4 is substituted into the apparatus of FIG. 1. Fitted over the furnace tube 12 is a cap 40 into which are fitted three coaxial sleeves 42, 43 and 44. The outer and inner sleeves 42 and 44 are formed with conduits 46 and 48, respectively, each for receiving a gaseous mixture of a reactant. The central sleeve 43 has a conduit 47 for receiving inert gas.
Fitted within the inner sleeve 44 is a long, small-diameter cylindrical inlet tubing 50 that is flared outwardly at its entrance 52. The inlet tubing 50 has a uniform inside diameter barely larger than the tow 20 which is being carried through the APCVD apparatus as modified in FIG. 4. Each of the cap 40 and the inlet tubing 50 is formed with a conduit 56 and 57, respectively, for receiving inert gas.
In a modified version of the apparatus shown in FIG. 4 that has been used experimentally, the sleeve 42 was omitted and the second reagent was added through the conduit 56.
The apparatus of FIG. 4 also differs from that of FIG. 1 by a liner 58 that is fitted into the furnace tube 12. The liner is easily replaced and deposits are thus eliminated.
As illustrated in FIG. 5, one may introduce a low-vapor-pressure liquid, by the use of a circulating pump, directly into the furnace tube 12 of FIG. 1 through an arm 60 of a tube 62 that is fitted into a cap 63. The addition of a carrier gas through an inlet 64 of the tube 62 prevents discontinuous, dropwise addition of the reactant. To prevent the buildup of a "puddle" below the exit 66 of a fiber-receiving tubing 68, it is advantageous to tilt the apparatus a few degrees as illustrated.
It is evident to those skilled in the art that a solid reagent may be introduced by an auger.
FIG. 6 shows heat-treating or APCVD coating apparatus 70 that include a furnace 71 containing a furnace tube 72 in-line with the furnace tube 12 and liner 58 of FIG. 4. When exposure of the fibrous material to the atmosphere between the two furnaces is undesirable, a long transfer tubing 75 is used, and it has gas inlet arms 78 and 79 that serve to establish the desired atmosphere. The uniform cross-sectional area of the transfer tubing is barely large enough to receive the tow 20 (the path of which is indicated by a phantom line). The length of the transfer tubing 75 is selected so that there is sufficient space to allow cleaning.
The gap between the liner 58 and the transfer tubing 75 is kept small to restrict exposure of the fibrous material to the atmosphere. To further minimize the exposure and to ensure against carrying gases and soot from the liner 58 into the transfer tubing, a conduit 80 directs a neutral gas into the gap. For the same reason, the arm 79 near the inlet 80 to the transfer tubing preferably directs its gas toward the inlet as shown.
The inlet of furnace tube 72 is fitted with cap 74, that is formed with gas inlet conduit 76, through which the desired heat treatment atmosphere is established. To use the second furnace for CVD, conduit 76 would be replaced with the type illustrated as 28 in FIG. 1, thus allowing the discharge of one of the reagents within the furnace 71. The cap 74 is also fitted with a second conduit 77 (corresponding to conduit 30 in FIG. 1).
FIGS. 7a and 7b show two views of equipment for modifying apparatus 10 of FIG. 1 for the coating of a continuous narrow strip of fabric or a plurality of side-by-side tows (not shown). Fitting through a stopper 81 in the inlet of the furnace tube 12 is a long inlet tubing 82 having a uniform slot-like cross-sectional area, except being flared outwardly at its entrance 83. The slot-like area is barely large enough to receive fibrous material to be coated. Also fitting through the stopper 81 are a pair of conduits 84 and 85, through each of which a gaseous mixture of one or more CVD reagents is fed. To keep out air, a stream of inert gas is passed through each of a pair of arms 87 and 88 formed in the inlet tubing 82.
FIGS. 8-11 are discussed in connection with the working examples below.
In most cases, fibrous material to be coated is sized. The sizing is easily removed by passing the fibrous material, prior to entering the CVD apparatus, through an open-tube furnace at a temperature sufficient to burn off the sizing. When it is desirable to size fibrous material after it has been coated by CVD, this can be done continuously between the coater and the takeup spool.
In some cases, the fibrous material to be coated should be protected from the CVD atmosphere. In case of NEXTEL® 480, this can be accomplished by depositing a carbon coating during the preparation of the fiber. Alternatively, sizing may be pyrolized in an inert atmosphere. If a thicker carbon subcoat is desired, a gaseous carbon source may be added to the inert gas stream. A carbon subcoat may also have the additional advantage of establishing a favorable bond strength between the fibrous material and the CVD coating. Subcoats other than carbon (e.g., BN) can provide the same advantages.
Penetration of the reagents between the filaments can be beneficially affected by pulsing the gas flow. This is accomplished by passing at least one of the gas streams through a valve that can be set, e.g., at one-second-on/one-second-off, such as valve No. 52C19T34-8 available from Valcor Engineering Corp., of Springfield, N.J.
It is evident to those skilled in the art that the properties of the coatings can be varied by changing the composition of the reactants, their partial pressures and flow rates, and the deposition temperature. Materials with narrow homogeneity regions, such as SiC, can be deposited with or without excess silicon or carbon by the suitable choice of temperature and of the Si/C/H ratio in the reactant gas stream. See, for example, H. J. Kim & R. F. Davis, J. Appl. Phys., Vol. 60, p. 2897 (1986). In the case of coatings with a wide homogeneity range, such as Ti x C 1-x , the value of x can be predetermined by the suitable choice of temperature and of the partial pressures of the reactants. See F. Teyssandier, et al., J. Electrochem. Soc., Vol. 165, p. 225 (1988).
The temperature range of the process can be lowered by using highly reactive gas(es) for example, SiH 4 or BH 3 as the sources for silicon and boron respectively.
The coatings deposited at low temperatures tend to be amorphous. If highly crystalline coatings are desired, higher temperatures should be employed. In the case of highly reactive gases, this leads to homogeneous nucleation and growth, i.e. to poor quality coatings and low yield. Hence it is advantageous to use less-reactive gases. For example, in the case of carbon, CH 4 may be used instead of unsaturated or higher molecular weight hydrocarbons. However, if too high a temperature is used, grain growth can take place in both the fiber and the coating, and this can adversely affect the mechanical properties. Also, other variables being constant, the number of filaments that break during the coating process increases with increasing temperature.
Using the process taught in this invention, coatings can be deposited on any fibrous material that is stable in the CVD gas stream at the deposition temperature. In the case of corrosive reactants, a thin precoat of a non-reactive material as a protective barrier allows the deposition of the desired coating.
As examples of the practice of the present invention, the following fibers were coated: aluminum borosilicate and mullite fibers, specifically the family of NEXTEL® fibers available from 3M Company, alumina fiber SV-01-lK available from Sumitomo; an alumina-zirconia fiber PRD166 available from E. I. duPont; and a carbon fiber AS4 G-12K available from Hercules.
Any suitable inert gas such as nitrogen, helium, argon, and neon can be used as the carrier gas.
Useful classes of refractory barrier coatings for the present invention include oxides, carbides, borides, nitrides, silicides, carbon and metals.
From the above discussion it can be seen by one skilled in the art that the properties of the barrier coatings (thickness, composition, crystallinity) can be varied at will, and that for a given set of coating properties, deposition conditions can be selected to minimize materials and process costs.
The techniques that were used for the evaluation of the barrier coatings are illustrated below:
Characterization Methods
To evaluate the usefulness of the present invention, it is necessary to determine the coating thickness distribution, the grain structures of the coatings, and the strengths of the coated fibers. The following characterization techniques were used:
Optical
Coating quality on transparent fiber was qualitatively determined by optical microscopy. The coated filaments were examined in cross-polarized light, preferably in the index oil corresponding to their refractive index. The coatings caused bright lines to appear at the two edges of the filaments. These lines were brightest at 45° orientations to the planes of polarization. The continuity and intensity of the lines is a qualitative indication of coating quality. Color of the lines, being due to interference between light reflected at the filament-coating interface and at the surface of the coating, allowed the qualitative calculation of the coating thickness.
A measure of coating thickness uniformity was obtained in the case of colored coatings on transparent fibers by measuring the light transmission through a number of filaments in an index oil matched to their refractive index. This approach assumes the absorption is proportional to the coating thickness. The measurements were made using the Zeiss PMl photometer with a circular aperture of 630 micrometers. The 100% transmission was set in a filament-free area. The percent transmission was plotted as a histogram. It shows the degree of coating thickness control obtainable by the present invention.
Mechanical Test Methods
The mechanical test results were determined using a Sintech Inc. (Stoughton, Mass.) computer-controlled load frame. A 1000-lb load cell, equipped with Instron Model No. 2712-003 pneumatic grips with rubber coated faces (Instron catalog #2702-015), was used for the tensile testing of the fibrous material. The gauge length for "Strand Strength" measurements was 15.24 cm. "Bend Strength" determinations were made using fiber samples which were 7.6 cm in length, bending them around a 1.27 mm diameter rod, and then applying tension.
Other Methods
SEM was used for the determination of the morphology of the coatings. Examination of fracture cross-sections allowed estimation of coating thickness. Observation of the degree of spalling, if any, adjacent to the fracture gave a qualitative indication of bond strength between fiber and coating.
TEM allowed the determination of crystal and grain structure.
Depth profiles obtained by Auger electron spectroscopy revealed the composition and, if any, the change in composition through the coating.
ESCA was used for the determination of composition and bonding in and near the surface. Due to the inability of the technique of focusing at a single filament, it cannot give depth profiles.
Elements in the coating that do not form part of the fiber were determined by standard techniques, e.g., by ICP or for carbon and nitrogen by the LECO method.
The electrical resistance was roughly determined by contacting the coated fibers with two probes.
Comparisons of results obtained on the same sample by various methods could in many cases be used for the estimation of their accuracy.
Various modifications and alterations cf this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. Therefore, it should be understood that this invention is not to be limited to the following examples in which parts are given by weight.
EXAMPLES
Example 1
In this example, the apparatus was like that of FIG. 1 having
length of furnace 11: 30 cm
inside diameter of furnace tube 12: 2.5 cm
inside diameter of inlet tubing 16: 0.4 cm
Hydrogen (190 cc/min) was bubbled through boiling (CH 3 ) 2 SiCl 2 to produce a gaseous mixture that was passed through a 20° C. reflux condenser and then through conduit 28 of FIG. 1 (called "Flux 1" in Table I). Argon (2100 cc/min) was passed through conduit 30 (called "Flux 2" in Table I). The apparatus was used to coat a 2000-denier, 760-filament tow (mullite with a 2% B 2 O 3 content available as NEXTEL® 480) that had a 0.2% carbon coating. This tow was pulled through the furnace tube (kept at 1050° C.) at 37 cm/min to provide a CVD coating about 100 nm in thickness as measured by electron microscopy and verified by calculations based on elemental analysis of carbon.
The resulting filaments of the tow had infinite electrical resistance. Their barrier coatings of SiC afforded a golden color to the filaments. Uniform orange-colored lines observed under cross-polarized light indicated a uniform coating thickness of about 130 nm. The coating thickness distribution, as shown by a histogram (FIG. 8) based on light absorption, was reasonably narrow. The composition of the CVD coating, as indicated by an Auger depth profile, was stoichiometric. A TEM micrograph (FIG. 9) showed most of the grains to be 1 to 3 nm in size.
Etching away the mullite cores with aqueous HF allowed the hulls to be observed (FIG. 10).
Examples 2-23
Lengths of the same carbon-coated tow used in Example 1 were provided with different CVD barrier coatings by the procedure of Example 1 except as indicated in Table I and except that Examples 10, 19 and 22 were coated using a concentric sleeve apparatus similar to that of FIG. 4; Examples 6 and 23 were coated using apparatus as shown in FIG. 5, with the xylene and Zr(BuO) 4 added as liquids. In Examples 14-16 and 31, TFAA denotes trifluoroacetic anhydride. About half of the filaments of Examples 3 and 4 that were coated with BN had white edges, thus indicating a thickness less than 170 nm. The other half had yellow edges, indicating a thickness exceeding 170 nm.
The last column in TABLE I gives the weight precent carbon that was deposited onto the fiber during its manufacture.
Examples 24-33
Most of the barrier coatings of Examples 1-23 caused deterioration in strength, especially in bend strength. However, undercoating with BN and/or with carbon counteracted the deterioration. Hence, lengths of the tow used in Example 1 were provided with CVD barrier coatings in the same manner as in Example 1 except that they were passed through the apparatus more than once. The deposition conditions of the multiple coatings are listed in Table II, with the outer coating listed first.
The effects of BN and carbon undercoats on the bend strengths of SiC-coated NEXTEL® 480 fibers were charted in FIG. 11 as curves 90 and 92, respectively. To generate the curve 90, the thickness of the BN layer was adjusted by changing the pulling speed between 0.73 and 3.54 m/min. It may be assumed that the coating thickness is an inverse function of the pulling speed. The pulling speed was likewise changed to provide fibers with varying weight percents of carbon as indicated by the curve 92.
Examples 34-35
Again proceeding as in Example 1, the simultaneous deposition of more than one phase yielded composite coatings as indicated in Table II. In Example 35 a 4000 denier NEXTEL® 480 was coated.
Heat-Treatment
When each of the tows of Examples 2, 24 and 34 was coated, it was carried in-line through a second furnace like that of FIG. 6 (80 cm long, 1150° C.) through which a stream of nitrogen was flowing. The resulting tows had improved resistance to hydrolysis as compared to tows that had been CVD coated in the same way except without heat-treatment. By performing heat treatments in oxidizing atmospheres, e.g., in air, oxynitrides were prepared. There was variation in the strength values of the various batches of fibers that were used as substrates.
Properties of the coated fibers of Examples 1-35 are listed in Table III. Most of the strength figures are averages of five measurements. An entry 0.0 indicates that the fiber was too weak to allow meaningful measurements to be made. The deviations in strand strength and bend strength refer to the change in strength relative to the uncoated tow, except in case of the multiple coatings where the values prior to the deposition of the outermost layer were the reference (in Examples 32 and 33, the changes from the uncoated tow are listed).
TABLE I__________________________________________________________________________ CARBON FLUX 1 FLUX 2 SUBCOATEXPL. COATING cm.sup.3 /min cm.sup.3 /min cm.sup.3 /min cm.sup.3 /min °C. cm/min %__________________________________________________________________________ 1 SiC (CH.sub.3).sub.2 SiCl.sub.2 30 H.sub.2 190 Ar 2100 1050 37 0.2 2 AlN AlCl.sub.3 40 H.sub.2 190 NH.sub.3 1060 N.sub.2 1900 700 91 0.2 3 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 73 None 4 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 354 None 5 B.sub.4 C BCl.sub.3 116 Ar 650 Et.sub.3 B 1212 H.sub.2 1350 1100 91 0.1 6 C xylene 60 N.sub.2 1100 N.sub.2 400 1000 107 None 7 Mo MoCl.sub. 5 24 Ar 590 H.sub.2 1000 Ar 280 700 30 0.2 8 MoSi.sub.2 MoCl.sub.5 20 Ar 500 SiCl.sub.4 200 Ar 810 1000 30 0.2 9 SiO.sub.2 Si(OEt).sub.4 23 N.sub.2 670 700 30 None10 Si.sub.3 N.sub.4 SiCl 83 N.sub.2 2200 NH.sub.3 760 1100 137 None11 SnO.sub.2 (CH.sub.3).sub.4 Sn 42 Ar 420 air 1670 500 61 None12 SnO.sub.2 (CH.sub.3).sub.4 Sn 42 Ar 420 air 1670 500 122 None13 SnO.sub.2 (CH.sub.3).sub.4 Sn 42 Ar 420 air 1670 500 30 0.514 SnO.sub.2 + F (CH.sub.3).sub.4 Sn 42 Ar 470 air 1670 TFAA 6 500 61 None15 SnO.sub.2 + F (CH.sub.3).sub.4 Sn 42 Ar 470 air 1670 TFAA 6 500 122 None16 SnO.sub.2 + F (CH.sub.3).sub.4 Sn 42 Ar 470 air 1670 TFAA 6 500 30 0.517 TaN.sub.2 TaCl.sub.5 7 N.sub.2 720 H.sub.2 1000 800 85 0.218 TiB.sub.2 TiCl.sub.4 40 H.sub.2 480 Et.sub.3 B 80 Ar 1350 900 91 0.119 TiB.sub.2 TiCl.sub.4 180 Ar 1600 BCl.sub.3 140 H.sub.2 1400 1000 354 0.520 TiN TiCl.sub.4 32 H.sub.2 3200 N.sub.2 1200 1000 183 0.221 TiN TiCl.sub.4 32 H.sub.2 3200 N.sub.2 1200 NH.sub.3 40 1000 183 0.222 ZrN ZrCl.sub.4 126 N.sub.2 740 NH.sub.3 490 N.sub.2 820 1000 91 0.123 ZrO.sub.2 Zr(BuO).sub.4 30 N.sub.2 1420 CO.sub.2 490 500 61 0.1__________________________________________________________________________
TABLE II__________________________________________________________________________ CARBON FLUX 1 FLUX 2 SUBCOATEXPL. cm.sup.3 /min cm.sup.3 /min cm.sup.3 /min cm.sup.3 /min °C. cm/min %__________________________________________________________________________MULTIPLE COATINGS24 AlN AlCl.sub.3 40 H.sub.2 190 NH.sub.3 1060 N.sub.2 1900 700 91 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 150 0.125 C xylene 60 N.sub.2 1100 1000 122 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 150 0.126 SiC (CH.sub.3).sub.2 SiCl.sub.2 30 H.sub.2 190 Ar 2100 1050 37 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 73 0.027 SiC (CH.sub.3).sub.2 SiCl.sub.2 30 H.sub.2 190 Ar 2100 1050 259 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 107 0.0 SiC (CH.sub.3).sub.2 SiCl.sub.2 30 H.sub.2 190 Ar 2100 1050 3728 SiC (CH.sub.3).sub.2 SiCl.sub.2 30 H.sub.2 190 Ar 2100 1050 37 0.2 C xylene 25 N.sub.2 1100 N.sub.2 380 1000 10729 Si.sub.3 N.sub.4 SiCl.sub.4 83 N.sub.2 2200 NH.sub.3 260 1000 137 BN NH.sub.3 490 BCl.sub.3 50 N.sub.2 1900 1000 150 None30 SnO.sub.2 (CH.sub.3).sub.4 Sn 42 Ar 420 air 1670 500 30 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 90 None31 SnO.sub.2 + F (CH.sub.3).sub.4 Sn 42 Ar 470 air 1670 TFAA 20 500 30 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 150 None32 TiB.sub.2 TiCl.sub.4 180 Ar 1600 BCl.sub.3 140 1000 354 C xylene 29 N.sub.2 1100 N.sub.2 380 1000 305 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 150 0.133 TiC TiCl.sub.4 36 H.sub.2 680 CH.sub.4 46 Ar 2270 1100 91 BN Et.sub.3 B 100 N.sub.2 1670 NH.sub.3 1650 N.sub.2 425 1050 90 0.1COMPOSITE COATINGS34 AlN--BN Et.sub.3 B 126 N.sub.2 2100 AlCl.sub.3 18 N.sub.2 420 800 61 0.1 NH.sub.3 106035 SiC--TiC CH.sub.3 SiCl.sub.3 30 N.sub.2 1700 TiCl.sub.4 50 CH.sub.4 40 1150 73 0.1__________________________________________________________________________
TABLE III__________________________________________________________________________ ELECTRICAL STRAND BEND RESISTANCE STRENGTH DEV. STRENGTH DEV.EXPL COLOR (k Ω/m) (kg) (%) (kg) (%)__________________________________________________________________________SINGLE COATING 1 SiC golden ∞ 2.4 -33 0.3 -92 2 AlN *grey 9000 3.9 -30 1.6 -48 3 BN straw ∞ 4.2 -4 3.2 -4 4 BN straw ∞ 3.2 -27 3.0 -12 5 B.sub.4 C black 3 × 10.sup.4 1.7 -64 1.0 -74 6 C black 76 4.2 -5 3.6 7 7 Mo black 2.4 4.7 -16 2.7 45 8 MoSi.sub.2 black 400 4.1 -28 1.9 2 9 SiO.sub.2 white ∞ 2.9 2.2 -3010 Si.sub.3 N.sub.4 white ∞ 1.2 1.211 SnO.sub.2 *golden 32 1.9 -56 0.012 SnO.sub.2 white 10 2.2 -48 0.5 -8613 SnO.sub.2 black 32 3.1 -36 0.5 -9114 SnO.sub.2 + F *olive 2.4 1.8 -57 0.015 SnO.sub.2 + F white 10 2.1 -51 0.5 -8116 SnO.sub.2 + F black 1.4 4.2 -15 0.5 -8617 Ta.sub.2 N black 5.6 5.9 0 1.7 -718 TiB.sub.2 black 8 5.9 28 2.8 -3019 TiB.sub.2 black 4 4.9 0 0.7 -7020 TiN black 170-6700 2.6 -52 1.0 -7521 TiN golden 1.1 0.0 0.022 ZrN olive ∞ 5.1 0 1.823 ZrO.sub.2 white ∞ 3.8 -20 3.2 10MULTIPLE COATINGS24 AlN/BN grey ∞ 4.5 -3 2.4 -3425 C/BN black 28 5.6 21 2.7 -3226 SiC/BN golden ∞ 4.2 0 1.3 -5927 SiC/BN/SiC golden ∞ 4.2 -21 2.4 -1128 SiC/C black 160 3.2 -27 0.8 -7529 Si.sub.3 N.sub.4 /BN white ∞ 1.2 1.230 SnO.sub.2 /BN *golden 36 2.0 -25 0.5 -8431 SnO.sub.2 + F/BN olive 1.4 2.3 -7 0.5 -8432 TiB.sub.2 /C/BN black 4 4.6 0 3.0 033 TiC/BN black 6 5.4 -10 4.4 76COMPOSITE COATINGS34 AlN--BN *grey ∞ 4.5 -12 3.1 3535 SiC--TiC grey 1 × 10.sup.4 7.6 -25 1.7 -68__________________________________________________________________________ *light color
Example 36
With the apparatus of FIG. 1 modified as in FIG. 7a and 7b, the procedure of Example 1 (with the changes noted) was used to coat a 2.5 cm wide woven borosilicate woven fabric (NEXTEL® 440) at a speed of 30 cm/min. Argon was passed through a solenoid value (one-second-on, one-second-off) and then through the conduit 84 at a rate of 2140 ml/min. Into the conduit 85 was fed a gaseous mixture of (CH 3 ) 2 SiCl 2 (120 ml/min) and hydrogen (720 ml/min). The temperature in the reaction zone was maintained at 1050° C. The tape inlet tubing 82 was purged with streams of argon to keep air out of the reactor.
The SiC-coated fabric was golden colored. In cross-polarized light, all filaments of the fabric showed orange lines. They were all completely coated. | Barrier coatings are deposited onto fibrous materials at atmospheric pressure by a continuous CVD process. A relatively short furnace tube with an unrestricted outlet is used. Thus, the supply and takeup reels do not need to be contiguous with the coating part of the apparatus. This allows the periodic removal of fuzz and soot without the interruption of the coating process. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an interface card with a control chip located on a side opposite to a side where a connector is located, and more particularly, to a display card with a graphics processing unit located on a side opposite to a side where a connector is located.
[0003] 2. Description of the Prior Art
[0004] In modern information society, computer systems are becoming necessities, such as desktops, notebook computers, servers, and so on. The operation speed of computers is getting faster and faster so that the computer is becoming powerful and is utilized in a wide variety of fields. Therefore, components of the computer generate more heat when processing operations than before. If the heat generated by the components of the computer cannot be dissipated effectively, the stability and operation speed of the computer will be reduced.
[0005] Please refer to FIG. 1 . FIG. 1 is a diagram of a display card 10 inserting into a motherboard 12 according to the prior art. The motherboard 12 includes a plurality of slots 14 which can conform to a standard of Peripheral Component Interface-Express (PCI-E), Peripheral Component Interface (PCI), and so on. A plurality of interface cards 16 is inserted into the slots 14 . The interface card 16 can be a sound card, a SCSI card, a network card, and so on. The motherboard 12 further includes a display slot 18 which can conform to a standard of Peripheral Component Interface-Express, Peripheral Component Interface, Accelerated Graphics Port interface, and so on, and the display card 10 is inserted into the display slot 18 for processing image signals.
[0006] Please refer to FIG. 1 , FIG. 2 , and FIG. 3 . FIG. 2 is a front view of the display card 10 shown in FIG. 1 according to the prior art. FIG. 3 is a back view of the display card 10 shown in FIG. 1 according to the prior art. The display card 10 includes a circuit board 20 which can be a printed circuit board, and a bracket 22 connected to the circuit board 20 for wedging in an opening of a casing (not shown in figures). The bracket 22 can be an L-shaped bracket. A plurality of connectors 24 is positioned on the bracket 22 for outputting or receiving image signals. The connectors 24 are positioned on the front side A 1 of the circuit board 20 of the display card 10 , wherein the front side A 1 is a front side of the circuit board 20 when the bracket 22 is on the left of the circuit board 20 , and a back side A 2 is a front side of the circuit board 20 when the bracket 22 is on the right of the circuit board 20 . The display card 10 further includes a graphics processing unit 26 installed on the front side A 1 of the circuit board 20 for controlling operation of the display card 10 , and golden fingers 28 for inserting in the display slot 18 of the motherboard 12 . The golden fingers 28 can conform to a standard of Peripheral Component Interface-Express (PCI-E), Peripheral Component Interface (PCI), Accelerated Graphics Port interface, and so on. The interface of the golden fingers 28 needs to match the interface of the display slot 18 . The golden fingers 28 include a front side 28 a and a back side 28 b defined according to the specification of the golden fingers 28 , such as PCI, PCI-E, AGP, and so on. The front side 28 a of the golden fingers 28 and the front side A 1 of the circuit board 20 are located on the same side, and the back side 28 b of the golden fingers 28 and the back side A 2 of the circuit board 20 are located on the same side. The display card 10 further includes a plurality of video memories 30 installed on the circuit board 20 . The video memories 30 can be installed on the front side A 1 or the back side A 2 of the circuit board 20 .
[0007] As shown in FIG. 1 , conventionally the graphics processing unit 26 is positioned on the front side A 1 of the circuit board 20 , that is, on the same side as the front side 28 a of the golden fingers 28 . Hence the graphics processing unit 26 is located between the circuit board 20 and a neighboring interface card 16 . Especially for a motherboard of ATX specification, the front side A 1 of the circuit board 20 of the display card 10 is close to the neighboring interface card 16 . When the graphics processing unit 26 processes complicated operations, such as 3D image processing, so as to generate lots of heat, the heat cannot be dissipated easily due to the narrow space between the display card 10 and the neighboring interface card 16 because of the short gap between the slot 14 of the motherboard 12 and the display slot 18 , so that the temperature of the display card 20 will increase and the stability of the computer and the service life of the display card 10 will be reduced.
[0008] For solving the heat-dissipating problem of the graphics processing unit 26 of the display card 10 , a fan can be installed on the display card 10 and a heat pipe can be applied to transmit heat generated by the graphics processing unit 26 to a heat sink (not shown in figures) positioned on the back side A 2 of the circuit board 20 . But the above-mentioned solutions can not solve the heat-dissipating problem effectively and the cost of the display card 10 will increase.
SUMMARY OF THE INVENTION
[0009] It is therefore a primary objective of the claimed invention to provide an interface card with a control chip located on a side opposite to a side where a connector is located for solving the above-mentioned problem.
[0010] According to claimed invention, an interface card includes a bracket, a circuit board including a first side and a second side, at least one connector connected to the bracket and the first side of the circuit board, and a control chip positioned on the second side of the circuit board.
[0011] According to claimed invention, an interface card includes a bracket, and a circuit board including a first side and a second side wherein the circuit board is fixed on the right of the bracket, golden fingers are positioned on the bottom of the circuit board, and the first side is a front side of the circuit board when the bracket is on the left of the circuit board. The interface card further includes a control chip positioned on the second side of the circuit board.
[0012] According to claimed invention, an electronic appliance includes a motherboard including a plurality of slots, and at least one interface card including a bracket, and a circuit board including a first side and a second side wherein the circuit board is fixed on the right of the bracket, golden fingers are positioned on the bottom of the circuit board, and the first side is a front side of the circuit board when the bracket is on the left of the circuit board. The interface card further includes a control chip positioned on the second side of the circuit board.
[0013] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagram of a display card inserting into a motherboard according to the prior art.
[0015] FIG. 2 is a front view of the display card shown in FIG. 1 according to the prior art.
[0016] FIG. 3 is a back view of the display card shown in FIG. 1 according to the prior art.
[0017] FIG. 4 is a diagram of a display card of an electronic appliance inserting into a motherboard according to the present invention.
[0018] FIG. 5 is a front view of the display card shown in FIG. 4 according to the present invention.
[0019] FIG. 6 is a back view of the display card shown in FIG. 4 according to the present invention.
DETAILED DESCRIPTION
[0020] Please refer to FIG. 4 . FIG. 4 is a diagram of a display card 50 of an electronic appliance 48 inserting into a motherboard 52 according to the present invention. The motherboard 52 includes a plurality of slots 54 which can conform to a standard of Peripheral Component Interface-Express (PCI-E), Peripheral Component Interface (PCI), and so on. A plurality of interface cards 56 is inserted into the slots 54 . The interface card 56 can be a sound card, a SCSI card, a network card, and so on. The motherboard 52 further includes a display slot 58 which can conform to a standard of Peripheral Component Interface-Express, Peripheral Component Interface, Accelerated Graphics Port interface, and so on, and the display card 50 inserts in the display slot 58 for processing image signals.
[0021] Please refer to FIG. 4 , FIG. 5 , and FIG. 6 . FIG. 5 is a front view of the display card 50 shown in FIG. 4 according to the present invention. FIG. 6 is a back view of the display card 50 shown in FIG. 4 according to the present invention. The display card 50 includes a circuit board 60 which can be a printed circuit board, and a bracket 62 connected to the circuit board 60 for wedging in an opening of a casing (not shown in figures). The bracket 62 can be an L-shaped bracket. A plurality of connectors 64 is positioned on the bracket 62 for outputting or receiving image signals. The connectors 64 are positioned on the front side A 1 of the circuit board 60 of the display card 50 wherein the front side A 1 is a front side of the circuit board 60 when the bracket 62 is on the left of the circuit board 60 , and a back side A 2 is a front side of the circuit board 60 when the bracket 62 is on the right of the circuit board 60 . The display card 50 further includes a graphics processing unit 66 installed on the back side A 2 of the circuit board 60 for controlling operation of the display card 50 , and golden fingers 68 for inserting in the display slot 58 of the motherboard 52 . The golden fingers 68 can conform to a standard of Peripheral Component Interface-Express (PCI-E), Peripheral Component Interface (PCI), Accelerated Graphics Port interface, and so on. The interface of the golden fingers 68 needs to match the interface of the display slot 58 . The golden fingers 68 includes a front side 68 a and a back side 68 b defined according to the specification of the golden fingers 68 , such as PCI, PCI-E, AGP, and so on. The front side 68 a of the golden fingers 68 and the front side A 1 of the circuit board 60 are located on the same side, and the back side 68 b of the golden fingers 68 and the back side A 2 of the circuit board 60 are located on the same side. The display card 50 further includes a plurality of video memories 70 installed on the circuit board 60 . The video memories 70 can be installed on the front side A 1 or the back side A 2 of the circuit board 60 .
[0022] The graphics processing unit 66 is positioned on the back side A 2 of the circuit board 60 , that is, on the same side as the back side 68 b of the golden fingers 68 instead of being located between the circuit board 60 and a neighboring interface card 60 . Especially for a motherboard of ATX specification, the front side A 1 of the circuit board 60 of the display card 50 is close to the neighboring interface card 56 and the back side A 2 of the circuit board 60 of the display card 50 is not close to any interface card so that there is enough space for dissipating heat. That is, because the graphics processing unit 66 is positioned on the back side A 2 of the circuit board 60 , the heat generated by the graphics processing unit 66 can be dissipated effectively instead of being blocked by other interface card 56 .
[0023] Besides the above-mentioned embodiment, the present invention discloses that a control chip can be installed on the back side of the interface card, such as a sound card, a SCSI card, a network card, and so on.
[0024] In contrast to the conventional display card, the graphics processing unit of the display card according to the present invention is installed on the back side of the display card so that there is enough space for dissipating heat generated by the graphics processing unit instead of being blocked by other interface card. Therefore, heat generated by components of the computer can be dissipated effectively so that the stability of the computer and the service life of the display card will increase. Additionally, the present invention does not need to utilize additional thermal modules for dissipating heat generated by the graphics processing unit so that the cost of the display card can be reduced.
[0025] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | An interface card includes a bracket, a circuit board including a first side and a second side, at least one connector connected to the bracket and the first side of the circuit board, and a control chip positioned on the second side of the circuit board. | 6 |
This invention was made with Government support under Contract Number DTFA01-88-C-00042 awarded by the Federal Aviation Administration. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention disclosed generally relates to multiple target tracking radar systems which determine the states of individual objects in a clutter environment.
2. Background Art
The present invention is intended for the real time tracking of moving objects in a clutter environment, such as for the purpose of traffic control of aircraft within an air space. The invention is a technique for multiple sensor tracking which distributes the track processing among multiple processing entities, but coordinates the track estimates such that the track states and covariances represent the equivalent of a centralized estimate. In the prior art three basic modes of tracking were available: centralized, single sensor distributed, and combined.
In centralized tracking shown in the prior art of FIG. 1, all sensor data is fed to a central processor. This method is particularly vulnerable to processor failure. However, it produces accurate results because all sensor measurements are used in a close to optimal fashion.
In a sensor level tracking system, the outputs shown in prior art FIG. 2a are available to the user. This method is not as vulnerable to processor failure as a centralized tracking design. This is because in the event of any one sensor or tracking system failure, tracking outputs may be derived from a different sensor with overlapping coverage. However, sensor level tracking does not provide tracking outputs which are as accurate as a centralized design.
In a combined tracking system shown in prior art FIG. 2b, each sensor processor forms a sensor level track. These tracks are then combined at a central processing entity. This method is less vulnerable to processor failure because of the redundancy in the sensor level processors (although the method is still vulnerable to central processor failure). The method also achieves the accuracy of a centralized design. However, the method is computationally expensive since both the sensor level and central processors must be supported, as well as the data communications between the sensor level and central level processors.
What is needed is a method of multiple sensor tracking which is entirely distributed, allowing for better overall tracking system reliability. If any one processing entity or sensor fails, the tracking process should be able to continue. The tracking system should take full advantage of all available sensor inputs for high accuracy. Finally, the communications and processing complexity should be at least as low as for that of sensor level tracking.
The present invention achieves these objectives. That is, the invention fully distributes track processing and produces results which are equivalent in accuracy to results derived from a centralized multiple sensor tracking system. The complexity of the design is low because the computations are entirely distributed.
Definitions
State: Represents the condition of a given system or object. Defined as a vector; In a Cartesian representation of a two dimensional Newtonian dynamic system, for example, the state, x, may have six components: x=[X Y X' Y' X" Y"]where X is the X position, Y is the Y position, X' is the X component of the velocity, Y' is the Y component of the velocity, X" is the X component of the acceleration, Y" is the Y component of the acceleration.
Covariance: Represents the uncertainty in the state estimate, and is defined as the second moment of the expected value of the state minus the expected value of the state:
R=E{(x-E[x])(x-E[x]).sup.t }
Where X is the state vector consisting of one or more components, R is the covariance matrix, and t represents the transpose operator.
Reference
Samuel S. Blackman, "Multiple Target Tracking with Radar Applications," ARTECH House, 1986, contains general background information on target tracking, the teachings of which are incorporated herein by reference.
OBJECTS OF THE INVENTION
An object of the invention is to establish and maintain a single system track for a single aircraft in a distributed processing environment. This object is achieved through the communication of track state and covariance information among processing entities. Each processing entity processes a single sensor's observations for a given track.
SUMMARY OF THE INVENTION
To achieve the foregoing objects in accordance with the purposes of the invention as embodied and broadly described herein, a method has been developed for multiple sensor tracking of objects which distributes the data association and track filtering functions among multiple processing entities but coordinates the track estimates such that the track states and covariances represent the equivalent of a centralized estimate. The invention establishes and maintains a single system track of a single object in a distributed processing environment. This is achieved via the communication of track information among processing entities which each process a single sensor's observations.
The multiple target tracking system receives a target report from a sensor to a processing node, associates the target report with a specific track, updates the track's state and covariance, and broadcasts the track's state and covariance to the other processor nodes. The other nodes receive the broadcast track state and covariance information and replace their present track state and covariance with the newly received broadcast information. The newly updated track state and covariance is then available at all nodes for the purposes of continued data association and multiple sensor track state and covariance updates.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and constitute a part of the specification, illustrate a preferred embodiment of the invention and together with a general description of the invention given and a detailed description of the preferred embodiment given below serve to explain the principle of the invention.
FIG. 1 is a prior art figure of a centralized level tracking system.
FIGS. 2a and 2b are prior art illustrations of sensor level and combined tracking systems.
FIG. 3 shows a steady state three sensor tracking system with overlapping coverage.
FIG. 4 shows the target corresponding to track 1 derived by the processing entity 1.
FIG. 5 shows the processing entity's update to track 1 broadcast to the remaining sensors.
FIG. 6 shows the target correlation to track 1, processing entity 2 and its re-broadcast.
FIG. 7 shows sensors 1 and 2 simultaneously initiating new tracks.
FIG. 8 shows how new tracks are communicated within the processing entities.
DETAILED DESCRIPTION OF THE INVENTION
The invention is implemented in multiple processing entities. The processing entities may be individual physical processors, parallel processors invoked in a single, physical processing unit, or time shared processes invoked in a single physical processor. The invention can be implemented in any one or a combination of the above manners.
The invention details can be best illustrated by example. Shown in FIG. 3 is a case of three overlapping sensors and three tracks. Each processor processes the data in the corresponding sensor's coverage area. Assume that in the overlapping area, there are three tracks identified as T1, T2 and T3. Also assume that an identical copy of the state and covariance estimates is contained in each processing unit. Suppose that the next target report received in the system is reported from sensor 1 as shown in FIG. 4. This target report is to be processed by processing entity (PE) 1. The target report is processed through the data association function and is associated to track 1 as illustrated in FIG. 5.
After data association, the target is filtered through a smoothing algorithm. For example, a Kalman filter could be used. The track state and covariance for track 1 is updated. Next, the track state and covariance are broadcast to the remaining sensors within the system. PE 2 and PE 3 receive the updated track state and covariance, and replace their old versions of these estimates with the received estimates. This process is illustrated in FIG. 6. At this point in the process, all three PEs have identical state and covariance estimates for track 1.
Now suppose PE 2 next receives a target report for track 1. PE 2 associates the report to track 1, updates the track state and covariance estimates, and broadcasts the results. PE 1 and PE 3 receive the new state and covariance estimates and replace their versions with the received versions. Again, all PEs have identical state and covariance estimates for the track. This step in the process is illustrated in FIG. 6.
The process continues indefinitely in a similar manner. The results are track state estimates which contain contributions from all sensors with which the tracks are observed.
An important issue arises with regard to timing. It is possible for two PEs to update a single track at approximately the same time. This can result in two state and covariance estimates entering the system at approximately the same time. If the timing of the communications are such that receipt of the updates occurs at different times for different PEs, it is possible for two different state and covariance estimates to exist in the system for a single track.
To eliminate this problem, each PE monitors the times at which it receives external updates for each track. If two updates occur within a specified parameter of time of each other, then a selection rule is applied. This rule could, for example, compare the sum of the squares of the velocity covariance of the two updates. The track update with the lower covariance could be retained, while the track update with the higher covariance is discarded.
Another potential confusing situation arises during track initiation. If a new object appears in an overlapping coverage area, it is possible for two or more PEs to simultaneously initiate a track on the aircraft. This would result in the existence of two tracks in the system for a single aircraft--precisely the situation which the logic is intended to prevent.
The problem and its resolution is again best illustrated by example. As in FIG. 3, assume that the three sensors numbered 1 through 3 are serviced by PEs numbered 1 through 3. Also assume that a new object is observed simultaneously by PE 1 and PE 2. PEs 1 and 2 initiate new tracks on the object identified as T0 and T4, respectively. This situation is illustrated in FIG. 7.
Both PE 1 and PE 2 proceed to broadcast the newly initiated tracks, resulting in the situation diagrammed in FIG. 8. At this point, there are two tracks in each PE for a single aircraft.
To resolve the problem, logic is needed which identifies the situation. This logic is called "track fusion." Track fusion recognizes that more than one track is from the same aircraft, and merges the information from the two tracks. The track fusion function is executed in a processing entity when it receives a track which is in its area of interest, but which is not currently in its track data base. When such a track is received, it is placed into a special class. The track enters the track fusion function, and is not allowed to enter the local target to track correlation process until the track fusion process is complete. This important rule keeps the new track from competing for target reports with a possibly already existing track. In addition, this rule allows a better comparison of the new track to existing tracks by keeping the track state estimates reasonably independent.
The function of the track fusion algorithm is to recognize the existence of duplicate tracks and to merge them. There are many different possible techniques which can be used to provide the track fusion function. These techniques can be based upon either a Bayesian or Dempster-Shafer (evidential reasoning) methods, for example (See Blackman, Chapter 13). A technique used in the Air Traffic Control environment is a sequential decision scheme based on a cumulative statistical distance of the two tracks. The decision to merge two tracks is based on a state comparison scheme using as the underlying metric the statistical distance between state vectors.
The track fusion logic is not the subject matter of this invention disclosure; however, its use in the context of the distributed track processing is novel. In the design of this invention, the track fusion function is not used continuously. Once two tracks are merged through the track fusion function, they become a single system track. This single system track is then used in the data association and track filtering functions. In the design there is no need to continue to maintain the fusion processing of tracks once they are fused. Thus, the resources which need be devoted to track fusion processing are smaller than those needed for the general track combination process (prior art FIG. 2).
Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific detailed examples described. Accordingly, departures may be made from such described details without departing from the spirit or scope of the general inventive concept disclosed and claimed herein. | A technique is disclosed for multiple sensor tracking which distributes data association and filtering processing among multiple processing entities but coordinates the track estimates such that track states and covariances represent the equivalent of a centralized estimate. The object of the invention is to establish and maintain a single system track for a single aircraft in a distributed processing environment. This is achieved through communication of track information among processing entities which process a single sensor's inputs. Continued updating and re-broadcasting of process data are performed between the multiple sensor's processing entities. | 6 |
FIELD OF THE INVENTION
The present invention relates to computer system backups and, more particularly, to a networked computer system environment in which efficient backup techniques may be used off-line.
BACKGROUND OF THE INVENTION
An incremental backup system can generally be described as a system in which initially, a full backup is performed, and subsequently only changes relative to the full backup are stored. The full backup can be periodically updated, generally by adding the incremental change files to the previous full backup. Some systems may even keep track of two or three full backups e.g., on a rolling or circular buffering basis.
For example, as shown in FIG. 1A , at t 1 , a full backup F 1 of a system, disk, volume, or other collection of objects is performed. Restoring the system to the data stored in F 1 reproduces the system conditions at t 1 . At t 2 , a full backup is unnecessary due to the likelihood that most of the data has not changed. Accordingly, an incremental or partial backup F 1 _I 1 is performed, whereby typically only ‘changed’ portions of the backup target are recorded, so that the addition of F 1 and F 1 _I 1 produces the information for a system backup to time t 2 . Similarly, at t 3 , another incremental backup F 1 _I 2 is performed that represents the change from t 2 to t 3 . Accordingly, the addition of F 1 , F 1 _I 1 and F 1 _I 2 produces the information for a system backup to t 3 , and the process of producing additional incremental backups may continue indefinitely.
As shown in FIG. 1B , another full backup F 2 can be performed, e.g., at t 4 , and subsequently incremental backups F 2 _I 1 , F 2 _I 2 , etc. for corresponding full backup F 2 may be produced. The incremental backups F 2 _I 1 , F 2 _I 2 , and so on represent change to the backup target since full backup F 2 . Thus, as compared to FIG. 1A , the computer system performing full backups F 1 and F 2 can restore to, e.g., t 5 , more easily. In FIG. 1A , the addition of F 1 , F 1 _I 1 , F 1 _I 2 , F 1 _I 3 and F 1 _I 4 produces the information for a system backup to t 5 , whereas for FIG. 1B , only F 2 and F 2 _I 1 need be processed.
Furthermore, as shown in FIG. 1C , multiple full backup/incremental processes can be run simultaneously. After full backups F 1 and F 2 , incremental backup files may be produced for both F 1 and F 2 separately, and F 1 and F 2 may have different files, volumes, etc. as the target for backup. Still further simplifying potential backup calculations and operations is the cumulative incremental calculation to a particular time. FIG. 1D illustrates a cumulative to time N (CTN) calculation in the context of FIG. 1A . For example, in FIG. 1A , to produce a snapshot of t 8 , an addition of F 1 _I 1 , F 1 _I 2 , F 1 _I 3 , F 1 _I 4 , F 1 _I 5 , F 1 _I 6 and F 1 _I 7 is performed for a system backup. Since eventually the number of incremental calculations and subsequent additions to produce a snapshot at time N may become inefficient or unmanageable, a cumulative backup may be computed to a time N.
In FIG. 1D , a cumulative backup for an entire system to time t 6 (denoted F 1 _CT 6 ) is calculated representing or embodying the change of incrementals F 1 _I 1 , F 1 _I 2 , F 1 _I 3 , F 1 _I 4 from F 1 and any change occurring from t 5 to t 6 as well. Thus, to compute a backup of the entire system to time t 6 , F 1 and F 1 _CT 6 are processed or added, eliminating the need to process the individual incrementals such as F 1 _I 1 , F 1 _I 2 , F 1 _I 3 , F 1 _I 4 and F 1 _I 5 . To produce such a cumulative backup to a time t 6 , e.g., prior art techniques have examined the change of the target backup object from the time of a recent full backup to the target time for the cumulative backup. This is a comparison of the state of the system at the time of the full backup to the state of the system at the time of the cumulative backup. Thus, to produce a cumulative backup file, prior art techniques in essence produce an additional or separate incremental file for a time interval, measured from the full backup, that is greater than the time interval for a typical incremental file.
However, with respect to these types of incremental backup systems, a problem exists whereby particular kinds of restore operations may not require a processing a full backup including each and every incremental backup file. In essence, processing a full backup including each and every incremental backup file is computer resource intensive, with corresponding burdensome time consumption i.e., it takes a long time to perform such a backup. For example, if only a word processing application crashes, files incidental to and dependent upon that application should be the subject of restoring. Furthermore, certain crashes may be recurring, and thus information about files incidental to these crashes is valuable and may be the source of efficient restore operations for these types of crashes. Additionally, there is redundancy of information from incremental file to incremental file that is not exploited when each incremental file is utilized in a restore process.
In response to these difficulties, a back end system with co-location keys was developed. A typical back end system administers a collection of tapes that sequentially store incremental backup files. By picking out a set of files unique to a particular restore operation from the collection of tapes, and co-locating them on a single tape, the files advantageously can be co-located on a single tape avoiding time and resource intensive searching, and allowing faster and more efficient restore operations. However, today's tape co-location techniques are implemented in conjunction with an on-line computer system in order to perform the operations incident to co-location tape generation, and significant advances in storage size and access have occurred since the development of current generations of backup systems. On-line resources are premium resources compared to off-line resources and storage solutions have proliferated since the days of tape backup storage. Consequently, computing resources are wasted to accommodate prior art techniques.
Thus, it would be desirable to provide a technique that provides off-line collection and management of backup file subsets for different types of restore operations. It would be further advantageous to input portion(s) of a system to which efficient backup techniques would be suited. It would be further advantageous to monitor and analyze aspects of system restore operations, so that inefficiencies resulting from existing system backup or restore operations may be detected and made more efficient through the use of cumulative backup techniques tailored to the inefficiency. It would also be beneficial to utilize information contained in incremental files to promote efficiency, such as through the retrospective analysis of such information to produce cumulative backup file(s).
SUMMARY OF THE INVENTION
This invention relates generally to computer systems that utilize an incremental backup system, wherein one full backup is followed by a sequence of successive incremental backups. The present invention provides a way to restore a target object such as a volume, directory or a pre-defined collection of files to a particular time by restoring the last full backup embodying the backup target, the last computed cumulative backup embodying the backup target and possibly the incremental backups after the last computed cumulative backup, if there are any that relate to change in the backup target. The invention may thus accommodate the restore operation in a bounded amount of time by effectively managing the generation of full, incremental and cumulative backup files. Advantageously, the technique may be performed off-line for the analysis, collection and management of backup file subsets for different types of restore operations. Aspects of system restore operations are monitored and analyzed so that in response, off-line management and selection of efficient sets of backup files can be performed to correct inefficiencies that may be detected and to efficiently tailor restore operations to the system characteristics and patterns. If an application has a condition of bounded restore time, the present invention may efficiently tailor a set of cumulative backups to meet the condition of bounded restore time.
Other features of the present invention are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
The system and method for providing efficient off-line backup support to a computer system is further described with reference to the accompanying drawings in which:
FIGS. 1A through 1D are temporal diagrams representing prior art on-line backup techniques.
FIG. 2 is a block diagram representing a general purpose computer in which aspects of the present invention may be incorporated.
FIG. 3 is a block diagram representing an exemplary network environment with clients, servers and storage components in connection with which the present invention may be implemented.
FIG. 4 is an illustration of the co-location of storage blocks of a target object to create a cumulative efficient backup object.
FIG. 5 illustrates an exemplary flow description illustrating aspects of the efficient restore techniques of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates generally to computer systems that utilize an incremental backup system, wherein one full backup is followed by a sequence of successive incremental backups. Since prior art techniques utilize on-line production and maintenance of backup files, these techniques consume valuable on-line time and resources and do not flexibly accommodate unique system characteristics. The present invention provides a way to restore a volume, directory or a pre-defined collection of files to a time T 1 in a bounded amount of time by restoring the last full backup, then the last computed cumulative backup and then the relatively small number of incremental backups after the last computed cumulative backup, if any. Further, a plurality of cumulative backups may be calculated to accommodate multiple subsets of backup files for different backup targets for different times.
In accordance with the present invention, advances in off-line processing power and storage are brought to the context of traditional backup or restore operations. A computed cumulative backup is obtained by combining, preferably off-line although the process can be conducted on-line if resources are available for doing so, the results of two or more consecutive incremental backups e.g., incremental backups occurring at times T 1 , T 2 , T 3 , T 4 , . . . TN, T(N+1). Then, a Cumulative backup to Time N (denoted CTN) is the result of combining all the modifications that were recorded from T 1 to TN. The last version of each storage block is the one that is utilized in connection with a CTN calculation. The allocation map that describes CTN is the one present in TN, and the value of each of the allocated storage blocks that have changed since the last full backup is the last change present in the range T 1 to TN. For instance, if an allocated storage block S 1 of a target object is present in incremental backups T 1 , T 5 and T 7 , where 7#N, then in the present example, the storage block information that will be utilized for CTN is the information from T 7 , because it is not necessary to predate T 7 . Thus, sessions are advantageously inspected from most recent to oldest to find the target set of files desired for the CTN. Hence, for a particular storage block, the CTN computation need only go as far backwards from time N as to capture the most recent version of the storage block as found in the most recent incremental backup containing that storage block.
While these computations may be performed while a computer system is on-line, in accordance with the present invention, beneficially these computed cumulative backups also can be achieved off-line.
Thus, in accordance with the present invention, if the last incremental backup is TN, and CTN has been produced, then the restore of the volume to time N is achieved by first restoring the full backup and then restoring the CTN backup. This eliminates the reproduction of multiple incremental backups that may contain redundant information. Any writes to the volume occurring after time N, if any, are captured in incremental backups T(N+1), T(N+2), etc. Thus, if called for, these incremental backups may be included after the CTN backup is added to the full backup or a new CTN calculation can be determined for any of CT(N+1), CT(N+2), etc. The CTN backup calculation and its addition to the full backup can also be made off-line to produce a complete image of the volume or target object at time N.
FIG. 2 and the following discussion are intended to provide a brief general description of a suitable computing environment in which the invention may be implemented. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a client workstation or a server. Generally, program modules include routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
As shown in FIG. 2 , an exemplary general purpose computing system includes a conventional personal computer 20 or the like, including a processing unit 21 , a system memory 22 , and a system bus 23 that couples various system components including the system memory to the processing unit 21 . The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read-only memory (ROM) 24 and random access memory (RAM) 25 . A basic input/output system 26 (BIOS), containing the basic routines that help to transfer information between elements within the personal computer 20 , such as during start-up, is stored in ROM 24 . The personal computer 20 may further include a hard disk drive 27 for reading from and writing to a hard disk (not shown), a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29 , and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a CD-ROM or other optical media. The hard disk drive 27 , magnetic disk drive 28 , and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32 , a magnetic disk drive interface 33 , and an optical drive interface 34 , respectively. The drives and their associated computer-readable media provide non-volatile storage of computer readable instructions, data structures, program modules and other data for the personal computer 20 . Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 29 , and a removable optical disk 31 , it should be appreciated by those skilled in the art that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read-only memories (ROMs) and the like may also be used in the exemplary operating environment.
A number of program modules may be stored on the hard disk, magnetic disk 29 , optical disk 31 , ROM 24 or RAM 25 , including an operating system 35 , one or more application programs 36 , other program modules 37 and program data 38 . A user may enter commands and information into the personal computer 20 through input devices such as a keyboard 40 and pointing device 42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite disk, scanner, or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port, or universal serial bus (USB). A monitor 47 or other type of display device is also connected to the system bus 23 via an interface, such as a video adapter 48 . In addition to the monitor 47 , personal computers typically include other peripheral output devices (not shown), such as speakers and printers.
The personal computer 20 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 49 . The remote computer 49 may be another personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the personal computer 20 , although only a memory storage device 50 has been illustrated in FIG. 2 . The logical connections depicted in FIG. 2 include a local area network (LAN) 51 and a wide area network (WAN) 52 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet.
When used in a LAN networking environment, the personal computer 20 is connected to the LAN 51 through a network interface or adapter 53 . When used in a WAN networking environment, the personal computer 20 typically includes a modem 54 or other means for establishing communications over the wide area network 52 , such as the Internet. The modem 54 , which may be internal or external, is connected to the system bus 23 via the serial port interface 46 . In a networked environment, program modules depicted relative to the personal computer 20 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
The computer described above can be deployed as part of a computer network connected to remote or local storage components, and the present invention pertains to any computer system having any number of memory or storage units, and any number of applications and processes occurring across any number of volumes. Thus, the present invention may apply to both server computers and client computers deployed in a network environment, having remote or local storage. FIG. 3 illustrates an exemplary network environment, with a server in communication with client computers via a network, in which the present invention may be employed. As shown, a number of servers 10 a , 10 b , etc., are interconnected via a communications network 14 (which may be a LAN, WAN, intranet or the Internet) with a number of client computers 20 a , 20 b , 20 c , etc. In a network environment in which the communications network 14 is the Internet, for example, the servers 10 can be Web servers with which the clients 20 communicate via any of a number of known protocols such as hypertext transfer protocol (HTTP). Storage components 12 may be located anywhere in the system and may be used for remote, local, on-line or off-line storage of full, incremental and cumulative backup files for a target object of the computer system.
For explanatory purposes, a storage volume is a software abstraction of the underlying storage devices and is the smallest self-contained unit of storage mounted by an operating system and administered by the file system. Storage volumes abstract the physical topology of their associated storage devices and may be a fraction of a disk, a whole disk or even multiple disks that are bound into a virtually contiguous range of logical blocks. In today's complex computer system environments, storage volumes can be a diverse set of elements for which efficient and effective management is desirable. Volumes are constructed from one or more extents that are contiguous storage address spaces presented by the underlying storage devices. An extent is typically characterized by the size of the address space and a starting offset for the address space from a base of the media.
As used herein, target object refers to a set of data objects for which backup data to particular time(s) is desirable. The target object may include an entire volume, multiple volumes, a portion of a volume, the entire system, portions located across multiple volumes, portions located across network(s). In essence, a target object in accordance with the present invention is any data stored anywhere for which a backup to an atomic point in time is desirable.
Thus, each client computer 20 and server computer 10 may be equipped with various application program modules 36 , other program modules 37 and program data 38 , and with connections or access to various types of storage elements or objects 12 . The present invention can be utilized in a computer network environment having client computers for accessing and interacting with the network and a server computer for interacting with client computers. As mentioned previously, in accordance with the present invention, a volume, directory or a pre-defined collection of files (a target object) is restored to a time T 1 in a bounded amount of time by restoring the last full backup, then the last computed cumulative backup and then the relatively small number of incremental backups after the last computed cumulative backup, if any. The target object may be defined by a user or determined according to rules or an intelligent analysis of system characteristics. Further, a plurality of cumulative backups may be calculated to accommodate multiple subsets of backup files for different backup target objects for different times.
FIG. 4 is an illustration of the co-location of storage blocks of a target object to create a cumulative efficient backup object. It should be noted that backup, incremental and cumulative files are stored in memory blocks of a storage component 12 wherever located in the network. Accordingly, since some changes during a time interval may be more sweeping than for other time intervals, more or less blocks B 1 , B 2 , B 3 , etc. will be implicated. Thus, in the example of FIG. 4 , a full backup file F 1 is stored across eight memory blocks F 1 _B 1 through F 1 _B 8 . The first incremental file F 1 _I 1 at t 2 is stored in one block F 1 _I 1 _B 1 , the second incremental file F 1 _I 2 at t 3 is stored across three blocks F 1 _I 2 _B 1 , F 1 _I 2 _B 2 and F 1 _I 2 _B 3 , and so on. In accordance with the present invention, for a given target object, a cumulative file at a particular time may be created so that resource intensive searching through incremental files for the data necessary to restore a target object can be avoided at the time of restore, thereby significantly reducing the overall time needed to restore a target object from the time of its failure or corruption.
For example, it may be desirable to restore a target object, such as a word processing application and all of its dependent applications or objects, to a time t 9 . In accordance with the present invention, off-line (or on-line) calculation may be made wherein a file CT 9 is created that represents the change of a target object from a full backup F 1 to time t 9 . Accordingly if the word processing application crashes or is corrupted, a restore operation may be made from CT 9 in connection with F 1 . Because CT 9 contains the storage block mapping information of the target object, only the storage blocks of the target object need be restored during the processing of F 1 and CT 9 , thereby eliminating any restoring other than the target object.
Thus, in the example of FIG. 4 , if a target object had N storage blocks for restore purposes, and if the Nth storage block SN changed at time t 3 , the first storage block S 1 changed at t 6 and the second storage block changed at t 8 , a cumulative backup file for time t 9 may be generated as follows. In an order from most recent to oldest (from t 9 to t 1 ), change of the target storage blocks S 1 , S 2 . . . SN is analyzed. When the last storage block for which change has occurred is discovered, the analysis is complete and the generation of CT 9 may be achieved.
In the example, first the most recent change in S 2 is discovered in F 1 _I 7 _B 1 and copied into the second target object portion TOP_ 2 . Then, the most recent change in S 1 is discovered in F 1 _I 5 _B 2 and copied into the first target object portion TOP_ 1 . And so on, until the most recent change of the last storage block, SN, is discovered in F 1 _I 2 _B 3 and copied into the last object portion TOP_N. No particular order of the storage blocks S 1 to SN of the target object is necessary as long as all of the change of the target object is captured in the cumulative target object backup file. Thus, once CT 9 has been generated, preferably off-line, and since CT 9 includes the storage block mappings and the most recent change for the target object relative to the full backup file F 1 , a target object restore operation to t 9 is simplified and streamlined having been tailored to the target object. Any incremental changes occurring subsequent to CT 9 , if any, would also be accommodated by a restore operation to a time subsequent to t 9 .
In a presently preferred embodiment, CTN files are stored in Microsoft tape format (MTF), although any format suited to the storage of a cumulative backup file may be used. In MTF, a collection of files backed up from a hard drive are stored on tape as a data set, and there may be multiple data sets per tape. Data sets may span one or more tapes. The term tape family refers to a collection of one or more data sets appended together and spanning one or more tapes. In MTF, there are three main components: a tape data block, otherwise known as the tape header, one or more data sets, and on tape catalog information. MTF tape contains a tape descriptor block. The tape descriptor block is the first object on the tape and serves to identify the tape. In order to accomplish this it contains the following: a unique tape Family ID, a tape sequence number indicating to which family the tape belongs, the date the tape was added to its family, and the tape name and description.
FIG. 5 illustrates an exemplary flow description of the present invention showing further advantage achieved by controlling backup and restore processes to correct system inefficiency or to meet a system condition such as a bounded restore time. Step 500 is included to illustrate that a user may specify a target object and/or other parameters such as frequency of or conditions for cumulative backup calculations. This is advantageous because a user may be in the best position to determine the importance of or characteristics for a target object backup. Multiple procedures according to different priorities may be specified. However, there may also be default parameters for the system backup processes to follow, which may also be altered. As step 510 illustrates, a system may also be configured to analyze itself for what may be efficient generation of backup files or a good candidate for a target object. For example, a particular application may repeatedly crash when X, Y and Z conditions occur, and if so, the system could generate a rule wherein cumulative backup operations are tied to the times when X, Y and/or Z occur. According to the parameters/rules, either system or user specified, for the generation of full and incremental backup files at various times and under various conditions, at 520 , the files are generated and stored preferably in off-line storage components 12 . Once stored off-line, efficient management of the data may be effected whereby the cumulative backup files for a target object in accordance with the present invention are created (See e.g., FIG. 4 ). As mentioned in connection with 500 and 510 , these target objects may be specified by a user or determined according to system analysis. In this fashion, efficient backup procedures for target objects are implemented.
As suggested above, the frequency of cumulative backup calculations is a policy that supports the notion of bounded restore time. If it is known that there is an upper limit for restore operations, the frequency of cumulative backups may be controlled accordingly to bound the total restore time. As a general rule, the more cumulative backups that exist in accordance with the present invention, the shorter the time it will take to perform restore operations because CTN calculations generally contain greater informational value than an incremental backup. It should also be noted that more than one cumulative backup may be computed as part of the same request i.e., incremental backups may be examined for applicability to multiple cumulative backups having different criteria associated therewith. Lastly, a user may be in the best position to judge restore characteristics that may be beneficial to a particular computer system. The present invention thus provides the user with the flexibility to define valuable restore operations for which cumulative backups would streamline the restore process.
The various techniques described herein may be implemented with hardware or software, where appropriate, or with a combination of both. Thus, the methods and apparatus of the present invention, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage 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. In the case of program code execution on programmable computers, the computer will generally include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. One or more programs are preferably implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.
The methods and apparatus of the present invention may also be embodied in the form of program code that is transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via any other form of transmission, wherein, when the program code is received and loaded into and executed by a machine, such as an EPROM, a gate array, a programmable logic device (PLD), a client computer, a video recorder or the like, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code combines with the processor to provide a unique apparatus that operates to perform the indexing functionality of the present invention. For example, the storage techniques of the present invention may invariably be a combination of hardware and software to be utilized in connection with storing system data.
While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. For example, while in a preferred embodiment, Microsoft tape format (MTF) is the format used in connection with the generation of backup files and performance of restore operations, any format may be accommodated. It should be understood that many different communications and network protocols may be suited to the delivery of backup information in accordance with the present invention. Furthermore, it should be emphasized that a variety of computer platforms, including handheld device operating systems and other application specific operating systems are contemplated for use in connection with the backup techniques of the present invention. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the appended claims. | A technique is provided to restore a target object such as a volume, directory or a pre-defined collection of files to a particular time by restoring the last full backup embodying the backup target, the last computed cumulative backup embodying the backup target and possibly the incremental backups after the last computed cumulative backup, if there are any that relate to change in the backup target. Restore operations in a bounded amount of time are accommodated by effectively managing the generation of full, incremental and cumulative backup files. Advantageously, the technique may be performed off-line for the analysis, collection and management of backup file subsets for different types of restore operations. Aspects of system restore operations are monitored and analyzed so that in response, off-line management and selection of efficient sets of backup files can be performed to correct inefficiencies that may be detected and to efficiently tailor restore operations to the system characteristics and patterns. If an application has a condition of bounded restore time, a set of cumulative backups may be efficiently tailored to meet the condition of bounded restore time. | 8 |
TECHNICAL FIELD OF THE INVENTION
The present invention pertains in general to automobile valves, and more particularly, to a method for standardizing a valve utilized in the rebuilding of automobile engines.
BACKGROUND OF THE INVENTION
When an automobile is initially assembled at the factory, all the parts have a predefined manufacturing tolerance and therefore the interface between various moving parts can be predicted. However, after an engine has been utilized for some time, these parts wear and go out of tolerance. This wear usually results in failure of the engine.
When remanufacturing an engine, it is necessary to replace worn parts. However, the replacement parts typically are dimensioned to accommodate the overall wear of the engine. For example, when a valve guide is worn, it becomes somewhat enlarged along the central axis thereof. If a valve stem having the original manufacturer's tolerance were installed into the remanufactured engine, the space between the exterior surface of the valve stem and the interior surface of the valve guide would exceed acceptable tolerances. Therefore, some accommodation must be made for the various wearing surfaces and the cooperating relationship therebetween in the remanufactured engine.
Valves in particular on the remanufactured engine present some unique problems in that failure to meet acceptable tolerances can result in poor heat transfer, excessive oil consumption, etc. There are three key items of consideration with respect to the valve in a remanufactured engine. First, it is essential to ensure that the valve in a remanufactured engine properly seats in the head and that the valve seat itself is ground to acceptable tolerances to provide a smooth mating surface for the valve. The valve head must have a smooth mating surface to provide proper seating. Second, the valve stem and the valve guide must interface such that there is approximately between a 0.0015 to 0.003 inch clearance between the exterior surface of the valve stem and the interior surface of the valve guide. Further, it is necessary that heat be transferred from the valve guide to the head. Third, the keeper groove at the upper end of the valve stem defines the securing position for compressing the valve spring. If the position of the keeper groove relative to the exterior of the head is altered from that of the original manufactured engine, this will result in the valve spring having too little compression or too much compression.
When regrinding a valve seat, it is important to remove a sufficient amount of the seating surface to provide a smooth polished surface. Depending upon the degradation of this surface, the seat may have to be lowered into the head too great a distance. Since this would result in the new or remanufactured valve sitting too far into the head and also result in removal of too much of the seat, the solution would be to remove a larger portion of the seat and replace it with a cast iron donut insert. This is a relatively expensive procedure.
When a valve guide wears, prior procedures have required boring out the valve guide and inserting a liner which has an inner diameter sized to provide the appropriate tolerances with the valve stem. Of course, the appropriate valve stem must be selected to be mated with the new liner. The problem with utilizing some types of liners or inserts is that the liner is typically pressed into the bored out valve guide. Although this press fit is relatively tight, heat transfer through the new liner is somewhat impeded. This is due to the fact that the interface between the exterior surface of the liner and the interior surface of the bored out valve guide is poor.
To accommodate variations in the height of the keeper groove at the end of the valve stem above the engine head, shims are typically utilized. One purpose for shims is to account for the "deterioration" or set of the valve spring and thus provide more spring tension. In addition, the shims also account for grinding of the valve seat wherein the head of the valve will recede into the valve seat. This directly translates to the keeper groove rising above the engine head.
One problem that exists at present with remanufacturing engines and especially with the valves is that generally there is no standardized value for rebuilding and only standard valves are available. Therefore, it is necessary to utilize the above rebuilding techniques with unique tooling for each engine in many cases to accommodate these various standardized valves.
SUMMARY OF THE INVENTION
The present invention disclosed and claimed herein comprises a method and apparatus for remanufacturing a valve assembly. The valve assembly includes a valve seat, a valve with a valve head and a valve stem, a valve guide through which the valve stem reciprocates, a valve spring and a retainer for the valve spring disposed in a keeper groove at the end of the valve stem and a valve stem seal. The replacement valve includes a valve head that has a diameter at the seating surface thereof that exceeds the corresponding diameter on the valve in the original valve assembly. The seating surface of the valve seat is resurfaced to increase the diameter of the seating surface at the upper end thereof. When the valve head having the larger diameter is disposed in the resurfaced valve seat, it rides higher in the resurfaced valve seat than would an original valve in the same remanufactured valve seat.
In another aspect of the present invention, the replacement valve includes a valve stem that has a diameter that exceeds that of an original valve stem. The valve guide is bored out to a predetermined dimension that exceeds the normal wear that would be expected on the valve guide in the original valve assembly. The valve stem on the replacement valve is dimensioned such that a clearance is formed between the bored out valve guide and the replacement valve stem, approximating the clearance in the original valve assembly.
In yet another aspect of the present invention, a modified keeper groove is provided on the end of the valve stem with the dimension between the modified keeper groove and the valve head being less than the corresponding dimension on the original valve. As such, a predetermined additional amount of compression is imparted to the valve spring when the replacement valve is assembled into the valve assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
FIG. 1 illustrates a cross-sectional view of a valve seated against the valve seat;
FIG. 2 illustrates a side view of the valve seat and the action of the valve thereagainst for a new valve and valve seat;
FIG. 3 illustrates the position of the valve after some wearing has taken place;
FIG. 4. illustrates a prior art method for remanufacturing the valve seat with a standard valve;
FIG. 5 illustrates the remanufactured valve seat utilizing the oversize valve of the present invention;
FIG. 5a illustrates a top view comparison between the remanufactured valve seat for the prior art and for the oversize valve;
FIG. 6 illustrates a prior art method for remanufacturing the valve guide;
FIGS. 7 a and b illustrates the method of the present invention for remanufacturing the valve guide; and
FIGS. 8 a and b illustrates the relationship of the keeper groove for both a prior art system and for the valve of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is illustrated a cross-sectional diagram of a typical valve in a cylinder head. A throat 10 is defined in the interior surface of a cylinder head 12. The throat 10 is circular shaped and has a valve seat 14 disposed on the peripheral edges thereof. A valve head 16 is attached to a valve stem 18, the valve head 16 having a seating surface 20 on the peripheral edge thereof. The seating surface 20 is operable to interface with the seat 14 to seal the throat 10. The throat 10 communicates with a port 22 to either expel exhaust gases or to receive an air fuel mixture.
The valve stem 18 is operable to reciprocate within a valve guide 24 that is disposed in the cylinder head 12. The valve guide 24 is typically made of cast iron and provides adequate heat transfer to the cylinder head 12. Typically, the valve stem 18 is dimensioned to provide a gap with a clearance of approximately 0.003 inches between the exterior surface of the valve stem 18 and the interior surface of the valve guide 24. This clearance allows the valve stem 18 to reciprocate freely within the valve guide 24 while prohibiting oil from flowing through the gap. If the gap were significantly larger, this would result in oil passing down from the exterior of the head 12 into the port 22. Alternatively, if the gap were too small, this would result in seizing of the valve stem 18 within the valve guide 24. The flow of oil through the gap could be the result of gravity for overhead valve engines or the cylinder vacuum on the intake valve, and by the vacuum created by exhaust pulses on the exhaust valve.
The valve stem 18 has an upper end 26 which is operable to interact with one end of a rocker arm (not shown). The rocker arm is operable to force the valve head away from the cylinder head 12, thus opening the throat 10. A valve spring 28 is provided on the end of the valve stem 18 protruding from the valve guide 24. During assembly, the valve spring 28 is compressed such that a retaining member 30 can be inserted into a "keeper" groove 31 in the upper end of the valve stem 18. The pressure of the valve spring 28 is important to proper operation of the valve mechanism.
Referring now to FIG. 2, there is illustrated a detailed cross-section of a valve head 32 that interfaces with a seat 34 in a newly manufactured engine. In this configuration, the valve seat 34 conventionally has three surfaces, a seating surface 36 that is disposed at an angle of 45° with the horizontal, an upper surface 38 that is disposed at an angle of 30° with the horizontal and a lower surface 40 that is disposed at an angle of approximately 60° with the horizontal, the seating surface 36 disposed between the upper surface 38 and the lower surface 40. The valve head 32 has a seating surface 42 which is operable to seat against the seating surface 36 and an upper rim 44. The seating surface 42 is disposed at an angle with respect to the horizontal that is substantially equal to the angle of the seating surface 36, such that they form a seal when mated together. The rim 44 is disposed at an angle that is much greater than that of the seating surface 42.
When the cylinder head is manufactured, the portion of the metal forming the exhaust valve seat 34 is treated such that it is "hardened". This is represented by a region 48 which is indicated by a phantom line. The region 48 is approximately 0.015 to 0.060 inches thick and provides a relatively "hard" surface. Since the surface of the valve seat 34 is subjected to high temperatures and high impact forces between the seating surface 36 and the seating surface 42, this region presents a much higher degree of resistance to wear as compared to other surfaces on the cylinder head 12.
Referring now to FIG. 3, there is illustrated a cross-sectional diagram of the valve 32 and the valve seat 34 after wear. As the two seating surfaces 36 and 42 wear, the upper surface of the valve head 32 recedes downward into the valve seat 34 and downward along the seating surface 36 toward the lower surface 40. This is the result of the wearing away of the actual material that the valve seat 32 is comprised of. The result of this is that the valve stem associated with the valve head 32 rises outward from the cylinder head, thus relieving tension in the valve spring, which can eventually result in a poor seating operation. Further, damage can occur to the valve seat 36 as a result of this wear.
Referring now to FIG. 4, there is illustrated a cross-sectional detailed diagram of the prior art method for remanufacturing a valve seat 34, utilizing the same valve head 32. It is assumed that the valve head 32 is either new with dimensions that correspond to a new valve head or the seating surface 42 has been remachined. For the conventional remanufactured valve seat, the seating surface 34 is ground down at the same angle to result in a new seating surface 52. The new seating surface now extends downward into the region 48 such that the region 48 proximate to the new seating surface 52 is thinner than in the original cylinder head. Typically, the technician performing the grinding operation removes sufficient material to result in a smooth and shiny surface absent scratches or pits. If the amount of grinding required to achieve this condition is more than the remaining thickness of region 48, it will then be necessary to remove the entire seat 34 and put an insert in place thereof. Further, if the surface 52 results in the valve head 32 falling too far into the seat 34, it will also be necessary to utilize an insert.
When the new surface 52 is formed, this will result in the valve head 32 being slightly lower in the valve seat 34 by a dimension 54. This dimension 54 will also correspond to the additional height that the keeper groove on the end of the valve stem is above the surface of the cylinder head, thus resulting in the necessity for additional shims to provide adequate compression of the valve spring.
Referring now to FIG. 5, there is illustrated the preferred embodiment of the present invention utilizing an oversize valve head 58. The valve head 58 has a seating surface 60 similar to seating surface 42 and a rim 62 similar to the rim 44. The diameter of the valve head 58 is larger than the normal valve. In the preferred embodiment, the diameter is increased by a value of 0.030 inches. This results in a dimensional increase of 0.015 inches on the peripheral edge, as indicated by a dimension 64. Since the peripheral edge of the valve head 58 extends outward in the valve seat 34 an additional distance, the portion of the valve seat 34 upon which the seating surface 60 rests, the valve head 58 is in a closed position, will be higher than that with respect to the remanufactured valve of FIG. 4. Therefore, the original valve seating surface 36 need only be ground a sufficient amount to provide a smooth surface at a point closer to the upper portion of the upper surface 38. This results in a new seating surface 66.
It is important to note that the seating surface 60 is adjacent to a portion of the seating surface 66 that has a sufficiently greater amount of the region 48 disposed thereunder. This is the result of two factors. First, the portion of the original surface 36 in the valve seat 34 that is damaged is lower in the valve seat than that on which the seating surface 60 in the oversize valve 58 rests after remanufacturing the valve seat 34. Second, the upper surface of the valve head 58 proximate to the interior of the cylinder head is substantially in the original position as compared to a new cylinder head, as produced in the originally manufactured part. The result of this is that the keeper groove at the upper end of the valve stem diametrically opposite to the valve head 58 would be in the original position. If the keeper groove were placed in the same position on the end of the valve stem, this would result in the valve spring being disposed at the same position as that in the originally manufactured engine.
It can be seen by comparing FIGS. 4 and 5 that when utilizing the standard valve, it is necessary that the valve seat 34 be ground such that the surface 52 in FIG. 4 moves both in the horizontal and in the vertical direction. In the preferred embodiment of FIG. 5, the surface 36 is ground in the preferred embodiment such that the seating surface 66 of valve seat 34 moves substantially in the horizontal direction. This is due to the fact that the seating surface 60 of the valve moves in a horizontal direction due to the oversized valve head 58. In addition to grinding the original seating surface 36 to form the seating surface 66 in the valve seat 34, the lower surface 40 is also ground at the angle of 60° with respect to the horizontal to form a new lower surface 70.
Referring now to FIG. 5a, there is illustrated a comparison between both the prior art seating surface 42 in the embodiment of FIG. 4 and the seating surface 60 on the oversize valve 58 in the preferred embodiment of FIG. 5. It can be seen that the seating surface 60 sits farther up in the valve seat 34 than the seating surface 42 of the prior art embodiment. This is due to the increase in the diameter of the oversize valve head 58, also considering the fact that the angle of the final seating surfaces 52 and 66 is the same.
Referring now to FIG. 6, there is illustrated the prior art method for remanufacturing the valve guide. Since the original valve guide wears, it is necessary to bore the valve guide out to provide a modified valve guide 72. The modified valve guide 72 has an interior diameter that is too large for a standard valve stem. Therefore, a liner 74 is utilized which is press fit into the bored out valve guide 72 to provide an inner diameter dimension that is within tolerance. As described above, the tolerance is such that a 0.003 inch gap is provided between the exterior surface of a standard valve stem 76 and the interior surface of the liner 74. Some of the problems that exist with the liner 74 are the difficulty in assembling the final valve guide and also heat transfer between the liner 74 and the bored out valve guide 72.
Referring now to FIG. 7, there is illustrated a preferred embodiment for providing a remanufactured valve guide. In the preferred embodiment of FIG. 7, the standard valve stem 18 and the standard valve guide 24 are illustrated in the upper portion of the Figure. In lower portion of FIG. 7, the bored out valve guide 78 and an oversize valve stem 80 are illustrated. In the method for remanufacturing the valve guide of the present invention, a single oversize valve stem is provided. In this manner, the original valve guide 24, is merely bored out to a dimension that will provide a concentric surface along the entire length of the remanufactured valve guide 78. The dimension of the interior diameter on the remanufactured valve guide 78 is defined by the reaming tool that is utilized. Therefore, this can be a very tight tolerance. The oversize valve stem 80 can then be standardized such that only one diameter valve stem is required. No insert or liner 74 is required and this dimension will be acceptable for all valve stems. The procedure therefore will be to ream the original valve guide 24 out to a predetermined dimension. In the preferred embodiment, this is approximately 0.015 inches over the standard inner diameter. Second, a standardized oversize valve stem is then provided on the replacement valve. As compared to the prior art method, this provides significantly fewer steps. Further, since the material of the original valve guide 24 is the same as that of the remanufactured valve guide 78, heat transfer is substantially identical to that in the original manufactured engine.
Referring now to FIG. 8, there is illustrated a detailed diagram of the placement of the keeper groove in the valve stem 80 as compared to the placement of the keeper groove 31 in the original valve stem 18. As described above, the upper end of the valve stem 80 when an oversize valve head 58 is associated therewith is at approximately the same position after regrinding the valve seat 34 as was the upper end of the original valve stem 18. As such, the same tension would be placed on the valve spring 28, were the valve spring 28 replaced with a new valve spring 28. However, if the old valve spring 28 is utilized, there will be some deterioration or set present as a result of use. Therefore, it is desirable to increase the compression at the valve spring. It has been determined empirically that the valve spring should be compressed approximately 0.030 inches. Therefore, a keeper groove 84 in the remanufactured valve spring is disposed lower by a factor of 0.030 inches to compensate for the set of the metal, as indicated by dimension 82. Therefore, the original retaining member 30 can be inserted into the keeper groove 84 in the remanufactured valve stem 80 that, when compared to the original keeper groove 31, is lower by a dimension of 0.030 inches in the preferred embodiment.
By utilizing the standard valve having the oversize valve head, the keeper groove 84 can be disposed at a predetermined position which will automatically provide a predetermined amount of tension on the valve spring 28. This is to be compared with the prior art system wherein shims would be required between the top of the spring 38 and the retaining member 30 to accomplish the same result. With the use of the oversize valve head, the location of the keeper groove 84 relative to the keeper groove 31 in the original valve stem 18 is known to within a predetermined tolerance.
In summary, there has been provided a method for simplifying the remanufacturing of a valve assembly. A single standardized valve is provided which has an oversize valve head with an increased diameter. This oversize valve head allows the seating surface on the valve head to ride higher in the remanufactured seat, thus requiring less removal of the valve seat in order to provide an adequate seating surface and also prevents the upper end of the valve stem from being disposed too high relative to the valve spring. The valve of the present invention also has an oversize valve stem which allows the original valve guide to be bored out to a predetermined dimension which will accept the oversize valve stem. This oversized valve stem exceeds all standard valve stems by a dimension that is slightly greater than normal wherein the valve guide can be bored out to a predetermined dimension. A keeper groove is disposed at a lower position on the upper end of the valve stem as compared to an original valve stem. This allows the old valve spring to be compressed by a predetermined amount without the requirement of shims.
Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | A method and apparatus for remanufacturing a valve seat includes providing a valve having an oversize valve head (52) and an oversize valve stem (80). The oversize valve head has a seating surface (60) which rides higher in the valve seat (34) after resurfacing thereof. The seating surface (60) on the valve head (58) therefore rides higher on the new seating surface (66) in the valve seat (34). The oversize valve stem (80) accommodates a bored out valve guide (78) to allow a single size valve stem to be utilized. A keeper grove (84) is disposed on the upper end of the oversize valve stem (80) and dimensioned such that it is disposed a predetermined distance below the original dimension of a standard valve. This allows a predetermined amount of compression to be placed onto the valve spring (28) to account for fatigue therein. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on, and claims priority to, Japanese Patent Application No. 2005-189689, filed on Jun. 29, 2005, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an integrated circuit (IC) for controlling a switching power supply.
[0004] 2. Description of the Background Art
[0005] One example of recent efforts to reduce the burden on the environment is reducing the standby power consumption of electronic products. Switching power supplies, which convert a commercial power supply to a direct current in order to supply power to electronic products, are also no exception. And because there are many products to which timers and remote controllers are added, reducing power consumption during standby is becoming particularly urgent.
[0006] In a switching power supply having a relatively low output power, standby power consumption can be reduced by lowering the switching frequency and reducing switching loss during standby. Further, in such a relatively low power output switching power supply, a power supply for a normal load and a power supply for standby (sub-power supply) can be provided, and standby power consumption can be reduced by switching between the power supplies and causing them to operate in response to the state of the load.
[0007] One way of reducing standby power consumption with a single switching power supply, without using a sub-power supply, is a method using a switching power supply control IC having two modes—a normal operating mode and a standby operating mode. With a dedicated terminal, it is possible to switch between these two modes with a control signal external to the IC. In some cases where the external switching control signal is generated with a power supply device, and in other cases a signal from a microcomputer or the like is utilized (e.g., see Japanese Patent No. 2,956,681).
[0008] FIG. 5 shows an example of a control IC circuit having a dedicated terminal to which an external switching control signal is inputted, and which can be used as a control circuit of the converter system disclosed in Japanese Patent Application Publication (JP-A) No. 2002-209381, which employs a switching method that is the same as that in the conventional example described in Japanese Patent No. 2,956,681.
[0009] In the control IC shown in FIG. 5 , continuous switching is implemented in the normal operating mode, and burst switching using a burst frequency and a burst ON period created inside the control IC is implemented in the standby operating mode. Further, burst switching is an operation that repeatedly starts and stops high-frequency switching at a burst frequency that is lower than the frequency of the high-frequency switching operation. This will be described with reference to FIG. 5 .
[0010] The double circles shown in FIG. 5 represent terminals of the control IC. FB, CB and STB at the left side of FIG. 5 are input terminals, and OUT at the right side of FIG. 5 is an output terminal that drives the gate of a power MOSFET. Ordinarily, a photodiode or a phototransistor is connected with respect to GND (ground), and a return signal corresponding to the output voltage of the power supply is inputted to the FB terminal. This signal and an oscillation waveform that is an internal oscillation circuit (OSC) output are inputted to a comparator represented by the PWM portion, whereby a pulse having a width corresponding to the splitting of each signal is generated. This pulse becomes an output pulse for conducting pulse width modulation (PWM) control where the pulse width changes due to the return signal corresponding to the output voltage of the power supply.
[0011] A capacitor for determining the burst oscillation frequency in the standby operating mode is connected to the CB terminal. A burst circuit BURSTOSC switches between a constant sink/source current in accordance with the terminal voltage and outputs this to the CB terminal. The sink/source current is outputted with respect to the capacitor connected to the CB terminal, whereby triangle wave oscillation is conducted. The comparator represented by the OnTB portion compares the FB terminal voltage and the CB terminal voltage in the same manner that the PWM control pulse is generated, and generates a pulse with a width corresponding to the splitting of both voltages. The frequency of this pulse becomes the burst frequency, and the pulse width becomes the burst ON period.
[0012] The STB terminal is an input terminal for switching the operating modes of the control IC with an external signal, and inputs one of a High and a Low voltage. When the STB terminal voltage is High, the output signal of the OnTB portion is not transmitted from the next stage on by the OR circuit to which the STB terminal voltage is inputted. Thus, a pulse that is the same as the PWM portion output is outputted to the OUT terminal. This condition is called the normal operating mode, and the switching frequency at this time (i.e., the oscillation frequency of the circuit OSC) is f_OSC.
[0013] When the STB terminal voltage is Low, the OR circuit causes the output signal of the OnTB portion to be transmitted from the next stage on. Thus, AND outputs of the PWM portion and the OnTB portion appear at the OUT terminal. Here, assuming that f_OSCB represents the oscillation frequency determined by the circuit BURSTOSC and the CB terminal capacitor, f_OSCB is the burst frequency and is set to be about 1/100 or less with respect to f_OSC. Performing the AND operation between the high frequency pulse and the low frequency pulse in this manner implements burst switching.
[0014] As shown in FIG. 6 , the circuit OSC comprises comparators CP 1 and CP 2 , a reset/set flip-flop RSFF, inverters I 1 and I 2 , two constant current circuits Ict, two switches SW, and a capacitor C. The circuit OSC uses the comparators CP 1 and CP 2 to compare the output voltage Vct with a predetermined set value, charge or discharge the capacitor C in accordance with the result, and output the triangle wave signal that is illustrated.
[0015] The circuit BURSTOSC is configured in exactly the same manner as the circuit OSC shown in FIG. 6 . However, because their circuit constants are mutually different (e.g., the switching frequency f_OSC is higher than the burst frequency f_OSCB), the OSC current Ict is made larger than the Ict of the BURSTOSC so that the external capacitor can be quickly charged/discharged. That which finally determines the frequency is the capacitance value of the external capacitor.
[0016] In the circuit shown in, FIG. 5 , it is necessary to provide a signal generating circuit inside the switching power supply to input a signal from outside of the control IC in order to switch between the normal operating mode and the standby operating mode. Even when the signal generating circuit is outside the switching power supply, it is necessary to provide a circuit for receiving the signal inside the control IC. Thus, there is the problem that the number of parts of the device itself is increased.
SUMMARY OF THE INVENTION
[0017] It is an object of the present invention to provide a control IC where a normal operating mode and a standby operating mode can be switched between without increasing the number of parts. It is also an object of the present invention to provide a control IC that is also provided with an automatic switching function while leaving the manual switching function with an external control signal that conventional ICs have.
[0018] In order to solve this problem, a first aspect of the invention provides an integrated circuit for controlling a switching power supply, the integrated circuit judging whether or not the load is light with a comparison signal that is compared with a triangle wave or a saw-tooth wave by a PWM comparator and switching between a standby operating mode and a normal operating mode. The comparison signal inputted to the PWM comparator is a signal that is fed back from an output voltage for PWM control, but it is also a signal relating to the size of the load. That is, when the load of the power supply is heavy, the on-duty of the PWM control signal becomes larger in order to supply more power, and this is because the comparison signal becomes higher. Conversely, when the load of the power supply is light, it suffices for a little power to be supplied. For this reason, the on-duty of the PWM control signal becomes smaller, and this is because the comparison signal becomes smaller.
[0019] In a second aspect of the invention, the integrated circuit may include: a first setting terminal that manually sets, without recourse to the comparison signal, switching between the standby operating mode and the normal operating mode; and a second setting terminal that sets the switching between the standby operating mode and the normal operating mode to be automatically conducted with the comparison signal or to be manually conducted without recourse to the comparison signal.
[0020] In a third aspect of the invention, the second setting terminal may include a function as a threshold voltage setting terminal when automatically moving from the normal operating mode to the standby operating mode and is configured such that the threshold voltage is adjustable from the outside.
[0021] In a fourth aspect of the invention, the threshold voltage may be generated by dividing a power supply voltage using resistors.
[0022] In a fifth aspect of the invention, the integrated circuit may include a terminal that can set a delay time until moving to an actual operating mode after detecting an operating mode switching signal.
[0023] In a sixth aspect of the invention, the delay time may be generated by a charge/discharge circuit comprising a constant current circuit, a switching element and a capacitor.
[0024] In a seventh aspect of the invention, the comparison signal may be a signal fed back from a secondary side of an insulated switching power supply to a primary side via a photocoupler.
[0025] In an eighth aspect of the invention, the comparison signal may be an error signal generated by an error amp from a reference voltage and a signal fed back from an output of a non-insulated switching power supply.
[0026] According to the present invention, because the mode switching signal does not have to be generated outside of the control integrated circuit, there is the advantage that switching between the normal operating mode and the standby operating mode can be realized with a configuration having a minimum number of parts, such as a MODE terminal voltage capacitor and a circuit that generates a voltage that is input to the ATSTB terminal.
[0027] Further, due to the ATSTB terminal, the integrated circuit pertaining to the invention can also accommodate conventional switching resulting from a switching control signal generated outside of the control IC.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is circuit configuration diagram showing a first embodiment of the invention.
[0029] FIG. 2 is a circuit configuration diagram showing a second embodiment of the invention.
[0030] FIG. 3 is a circuit configuration diagram showing a third embodiment of the invention.
[0031] FIG. 4 is a circuit configuration diagram showing a fourth embodiment of the invention.
[0032] FIG. 5 is a circuit configuration diagram showing a conventional example.
[0033] FIG. 6 is a circuit configuration diagram showing a specific example of the circuits OSC and BURSTOSC of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIG. 1 is a configuration diagram showing a first embodiment of the invention. In contrast to the conventional example shown in FIG. 5 , the control IC is configured by the addition of a signal input terminal ATSTB and a MODE terminal for selecting between manual switching and automatic switching, a SEL portion (comparator), an AUTOH (automatic switching circuit) and an AUTOL portion (automatic switching circuit), various gate circuits NOT 1 , NAND 1 , NAND 2 , OR 2 , NOR 1 , NOR 2 , and N channel MOSFET MN 1 .
[0035] A manual switching/automatic switching determining circuit is configured by the SEL portion comparator and a threshold voltage (set or threshold value voltage) VTH_SEL, and the comparator output signal is inputted to the NAND 1 and OR 2 . The outputs of the NAND 1 and OR 2 are inputted to the NAND 2 and become a signal that drives the gate of the N channel MOSFET MN 1 . In other words, when the ATSTB terminal voltage is higher than that of the VTH_SEL, a High or Low signal corresponding to the STB terminal appears in the output of the NAND 2 , and when the ATSTB terminal voltage is lower than that of the VTH_SEL, a signal where the outputs of the AUTOH and AUTOL to which the FB terminal voltage is inputted are synthesized in the NOR 1 appears in the output of the NAND 2 . The AUTOH and AUTOL are automatic switching circuits and comprise threshold voltages VTH_H and VTH_L and the gates NOR 1 and NOR 2 .
[0036] A circuit configured by a constant current supply and the MODE terminal connected to the drain terminals of internal power supplies VDD, MN 1 and MN 1 is an operation delay circuit, and a capacitor for setting a delay time is connected to the MODE terminal. The MODE terminal is fixed to a GND by the MN 1 when the output of the NAND 2 is High, and is in the normal operating mode. The NAND 2 output is inverted and MN 1 is switched OFF, whereby the delay time is generated where charging is not conducted by a constant current with respect to the capacitor connected to the terminal. When the MODE terminal voltage rises and becomes High, an OnTB portion signal setting a burst operation in the OR 1 output is inputted to AND 1 and synthesized with the PWM signal, which becomes the standby operating mode where burst switching is conducted.
[0037] Next, a case will be described where the ATSTB terminal voltage is set to VTH_SEL or less, that is, the operation in the automatic switching mode. When the FB terminal voltage is VTH_H or greater, AUTOH (output signal of the comparator of the AUTOH portion) becomes High and AUTOL (output signal of the comparator of the AUTOL portion) becomes Low (VTH_L<VTH_H), and the NAND 2 output becomes High. Thus, MN 1 is switched ON and the MODE terminal is fixed to GND, which is the normal operating mode. When the FB terminal voltage drops and becomes VTH_L or greater and VTH_H or less, the output of the comparator AUTOH is inverted and becomes Low, but the output of NOR 2 remains High. Thus, the inverted result is not transmitted to the next stage on, and MODE terminal remains at GND and in the normal operating mode.
[0038] Moreover, when the FB terminal voltage drops and becomes VTH_L or less, the NAND 2 output is inverted to Low and MN 1 is switched OFF as a result of the signal AUTOL being inverted to High. Thus, charging of the MODE terminal connected capacitor is begun, and when the MODE terminal voltage becomes High, this becomes the standby operating mode.
[0039] At this time, when the FB terminal voltage exceeds VTH_L until the MODE terminal voltage becomes High, the signal AUTOL is again inverted, charging of the MODE terminal connected capacitor is interrupted, and the MODE terminal becomes fixed to GND and maintains the normal operating mode. This delay operation is a function for corresponding to sudden changes in the load of the power supply and is configured such that the operating mode of the control IC is not switched when this state does not continue to be maintained for the delay time even when the FB terminal voltage becomes the threshold voltage VTH_L (the threshold to switch from the normal operating mode to the standby operating mode) or less.
[0040] The circuit of FIG. 1 has the inherent function of automatically conducting switching between the normal operating mode and the standby operating mode, but is configured to be switched by an external signal in order to have more versatility (to be able to accommodate conventional use). However, because the automatic switching function and the switching function resulting from an external signal will be at odds if left to this configuration, the circuit is configured to select, with the ATSTB terminal, which of the functions to select.
[0041] If configured such that a signal is supplied from the outside to the ATSTB terminal, the load of the external circuit increases and there is no longer any purpose in providing an automatic switching function. Thus, the input to the ATSTB terminal is pulled up or pulled down at the portion of the terminal and not connected to another circuit block.
[0042] In this case, the STB terminal inputs the signal from the outside only when it has set switching resulting from the external signal. When automatic switching has been set, this terminal is pulled up or pulled down. This is because in the case of automatic switching, the signal inputted from the STB terminal is blocked by NAND 1 and there is no longer any purpose, so the input terminal cannot be left open.
[0043] FIG. 2 shows a second embodiment of the invention. The second embodiment is characterized in that the threshold voltage VTH_L (for switching between the normal operating mode and the standby operating mode) is created by dividing the internal power supply VDD of the control IC with resistors and connected to the ATSTB terminal, and the rest is the same as FIG. 1 . By appropriately setting the voltage VTH_L, a further reduction in external parts becomes possible.
[0044] The following three states can be listed in regard to the input to the ATSTB terminal in this case.
(a) Open: reference voltage is imparted to SEL and the AUTOL portion. Automatic switching is automatically set by setting two resistance values that divide VDD such that the reference voltage is <VTH_SEL. (b) Input High: Switching resulting from external signal is set. (c) Connect a resistor to terminal outside and adjust reference voltage value.
[0048] FIG. 3 shows a third embodiment of the invention. The third embodiment is one configured such that the operation delay time can be set not only in the standby operating mode moving time but also at the normal operating mode moving time by disposed not just a constant current circuit for charging the MODE terminal connected capacitor but also a discharge-use constant current circuit and PchMOSFET (MP 1 ).
[0049] FIG. 4 shows a fourth embodiment of the invention. As is clear from FIG. 4 , the fourth embodiment is one to which the functions of both FIG. 2 and FIG. 3 have been given; in other words, the threshold voltage VTH_L (for switching between the normal operating mode and the standby operating mode) is created by dividing the internal power supply VDD of the control IC with resistors and connected to the ATSTB terminal, and not only the constant current circuit for charging the MODE terminal connected capacitor but also the discharge-use constant current circuit is disposed.
[0050] The above assumes the insulated power supply device disclosed in Japanese Patent No. 2,956,681 as the power supply device. Consequently, the signal inputted to the FB terminal is a signal fed back from the transformer secondary side to the primary side via a photocoupler.
[0051] However, the present invention is also applicable to a non-insulated power supply device. In this case, an error amp may be inserted after the FB terminal, and the output of the error amp may be connected to the later stage PWM portion, OnTB portion, AUTOH portion, and AUTOL portion. That is, the signal compared with a triangle wave or saw-tooth wave by the PWM comparator becomes an error signal generated by the error amp from the reference voltage and signal fed back from the output of the non-insulated switching power supply.
[0052] It will be appreciated by those skilled in the art that numerous variations and modifications are possible, and that the invention may be practiced otherwise than as specifically disclosed herein without departing from the scope thereof. | An integrated circuit for controlling a switching power supply includes a signal input terminal in addition to a switching input terminal that is also provided in a conventional integrated circuit and is a terminal to switch IC operation modes using an external control signal. The switching input terminal signal is made valid when the signal input terminal voltage is higher than a threshold voltage, such that mode switching using an external control signal is enabled. When the signal input terminal voltage is lower than the threshold voltage, mode switching is automatically conducted by switching a MOSFET ON or OFF using output signals of portions of a comparator connected to a feedback terminal to which an output voltage of a power supply device is applied. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a National Phase of International Serial No. PCT/EP02/14417, filed Dec. 17, 2002.
FIELD OF THE INVENTION
[0002] This invention relates to a security paper for producing security documents, such as bank notes, identity cards or the like, having a through opening, and to a method and apparatus for producing such a security paper. The invention further relates to a value document, such as a bank note, identity card or the like, having a through opening.
DESCRIPTION OF THE BACKGROUND ART
[0003] WO 95/10420 describes a value document having a through opening punched thereinto after production thereof, said opening then being sealed on one side with a cover foil protruding beyond the opening on all sides. The cover foil is transparent at least in a partial area, so that upon an attempt to copy the value document the background will be visible and rendered accordingly by the copy machine. This permits forgeries to be easily recognized.
[0004] However, said known value document has the disadvantage that the opening produced by punching can likewise be produced by a forger. The color copy of an authentic value document no longer has the transparent area, but said area can subsequently be punched out analogously to the authentic value document and sealed again with a suitable cover foil. Forgeries are therefore difficult to recognize.
SUMMARY OF THE INVENTION
[0005] The invention is based on the problem of proposing a security paper and a value document having increased forgery-proofness in comparison with the prior art.
[0006] The basic idea of the invention is that by production of a “window opening” during sheet formation, i.e. during papermaking, the edge area of the opening will have characteristic irregularities which are not producible subsequently on the finished paper. The irregularities are expressed by the lack of a sharply cut edge or irregular accumulation of fibers in the edge area, and by individual fibers protruding into the opening. A rough check of this characteristic edge structure is already possible with the naked eye, while an exact check can be done with a magnifying glass.
[0007] The inventive edge structure ensures that the opening cannot be produced by subsequently punching a paper sheet. An opening produced in such a way therefore has a similar security value to a watermark produced during papermaking or a security thread embedded during papermaking.
[0008] Security paper is normally produced in broad webs with several copies disposed side by side. After completion, the webs are cut into sheets with e.g. 6×9 copies present thereon. Said sheets are printed and then cut into single copies.
[0009] If each single copy is to have a through opening, a corresponding number of elements are to be provided on the screen of the paper machine which prevent sheet formation exactly in the surface areas where the opening is needed. If the security paper is to have watermarks in addition, production is done as a rule on so-called “cylinder paper machines” wherein the screen is mounted on a rotating drum. In this case, the opening can be located in the area of the watermark.
[0010] The security paper according to the invention has at least one through opening produced during papermaking. To permit this opening to be produced, the screen of the paper machine must be provided with at least one water-impermeable, preferably elastic or movably mounted sealing element per copy. The sealing element prevents sheet formation in this area. To prevent fibers from being deposited on the sealing element during sheet formation, it is preferably formed so high that it protrudes clearly beyond the paper surface. Upon removal of the paper web by the take-off roll covered with pickup felt, however, it must be ensured that the sealing element does not hinder the contact between the moist and still very unstable paper web and the take-off roll, since the paper web will otherwise break in this area. For this reason the sealing element consists according to the invention of a highly elastic material which can be compressed by the take-off roll approximately to the level of the paper surface. Alternatively, the sealing element consists of a movably mounted, preferably rigid plastic or metal element which is lowered approximately to the level of the paper surface or therebelow either by the action of pressure of the take-off roll itself or by electronic control upon contact with the take-off roll.
[0011] Further possibilities for producing the opening are sealing the screen surface with a plastic material, such as a lacquer, whereby the plastic material is likewise to be understood as a sealing element according to the invention. Alternatively, rigid sealing elements in the size of the opening to be produced can be applied (e.g. soldered) to the screen surface, said elements having a thickness considerably greater than the thickness of the paper web.
[0012] In some cases it may be helpful to provide further drainage-reducing structures in the edge area of the sealing elements for producing a kind of rated breaking point in the paper web. This is because the cotton fibers principally used for security papers have the tendency to settle over the sealing elements unchecked, thereby preventing hole formation or at least making it more difficult.
[0013] The freeness-inhibiting structures can be for example special embossings in the papermaking screen, additional screen elements, possibly with a different mesh width from the original papermaking screen, or plastic structures. In principle, any conceivable structures can be used that delay freeness and thus form a bright corona around the opening to be produced. In some cases it is already sufficient to use only the freeness-inhibiting structures. For example, an annular embossing can be so designed that the inventive hole is produced upon removal of the paper web from the screen.
[0014] The paper web lying on the pickup felt and having the openings formed due to the sealing elements is then further processed into a self-supporting paper web in further method steps, such as calendering, sizing and drying. To improve hole formation one can, in addition or as an alternative to the freeness-inhibiting structures additionally used during papermaking, remove fibers protruding into the desired opening after paper formation, e.g. by punching or cutting, the fibers being removed only to the extent that the hole edge produced by papermaking is not destroyed or actually removed completely. For example, if a circular hole is to be produced but a fine web of fibers settles irregularly over the hole, the disturbing fiber web can be removed with a circular punching mold whose diameter is smaller than the desired hole. Then a hole edge produced by papermaking is always recognizable, possibly only in a partial area of the hole edge. The inventive security paper therefore has at least one opening whose edges are at least partly irregular and show a character similar to hand-made paper, unlike the sharp edges of a punched or cut opening.
[0015] The fibrous, irregular edge of the openings is visually recognizable and therefore serves as an authenticity feature that is easy to check. If forgery-proofness is to be increased further, at least one watermark can be formed in addition in the surroundings of the opening, or the opening produced in a watermark area. Depending on the type of watermark to be produced, this requires different measures on the papermaking screen. For producing two-level watermarks with a strong light/dark effect, metal wires or metal moldings (so-called electrotypes) are soldered to the papermaking screen. For producing multi-level watermarks, however, a three-dimensional relief is embossed into the papermaking screen. Combinations of screen embossing and other measures preventing sheet formation, such as electrotypes or the application of sealing compound, are also used in watermark production. The thereby obtained light/dark modulation in the security paper in the direct surroundings of the opening confronts the forger with hardly solvable problems.
[0016] The form of the watermark can be selected here so that it is meaningfully related to the outline contour of the opening, or the opening and the surrounding watermark form a connected motif.
[0017] The papermaking screen is preferably a cylinder. Since the sealing element is either elastic or at least movably mounted, however, the invention can also be readily used in fourdrinier paper machines.
[0018] The inventive goal of preventing or greatly hindering forgeries of value documents with an opening can also be obtained by producing a relatively large, thin area in the security paper by corresponding screen embossing and/or freeness hindrance with electrotypes and providing the inventive opening in said area, whereby the thin paper area protrudes beyond the opening at least on one side, preferably on all sides, so that upon transmissive viewing of the security paper the thin paper area stands out in contrast from the rest of the surrounding paper web. The opening can in this case be produced during papermaking, as described above. Subsequent punching or cutting, in particular laser cutting, of the security paper is likewise possible, however, since a forgery can be recognized by the lack of a thinner paper area in the immediate surroundings of the opening.
[0019] The thinner area in the security paper can have a uniform thickness or else be formed as a multi-level watermark. If the security paper consists of two-ply paper, it is also possible to provide one layer, preferably the thicker one, with a hole which is then covered by the second paper layer. In said second paper layer the inventive opening is finally incorporated subsequently, its dimensions being smaller than those of the hole produced in the first paper layer.
[0020] In the case of two-ply paper consisting of a thinner and a thicker layer, the inventive hole can of course also be located in the thinner layer.
[0021] The inventive opening can be composed of several partial openings separated from each other by paper bars. The partial openings can have any desired outline contours and are preferably used as an additional design element. For producing the particular partial openings all the above-mentioned methods for producing the inventive opening can be used analogously.
[0022] In accordance with a preferred embodiment of the invention, the opening is provided with a security element protruding beyond the opening at least on one surface of the security paper after production thereof. Said security element can consist of a simple transparent plastic film or else be executed as a multilayer security element having one or more visually and/or machine testable security features.
[0023] Said security feature can involve diffraction structures, such as reflection or transmission holograms, reflectively observable grating structures or volume holograms, thin-film elements or filter elements, such as polarizing filters or interference filters. Filter elements have in particular the advantage that they can be used for checking further security features provided on or in the security paper by making the opening congruent with said further security feature by folding the security paper. However, the security element disposed in the area of the opening can also carry a simple print or a moiré pattern as a security feature. The inks used for said print can have a substance with optically variable, luminescent, electrically conductive or magnetic properties. The optically variable substances can be in particular interference layer pigments or liquid crystal pigments.
[0024] The security feature can further consist of a metallization, whereby several different-colored metals can also be used. Rasterization of the metal layers or reflecting layers of diffraction structures is also possible. Any desired semitransparent layers can of course also be used. The security feature can furthermore consist of a perforation or a lens structure.
[0025] A sufficiently large area of the security element is preferably kept completely transparent to permit easy recognition of forgeries produced by a color copier. A copy does not have said transparent area.
[0026] The security element can be formed for example as a self-supporting label or embossed foil element protruding beyond the opening by a certain measure on all sides. With this solution it is advantageous if the security paper has a depression in the area of the bearing surface of the security element, so that the security paper has a continuous surface in said area. In extreme cases the security element can cover the security paper or value document all over. This solution can also be provided on both sides of the security paper or value document.
[0027] The depression can be produced by compressing the security paper in this area before application of the security element. However, it is particularly simple to already produce the depression during papermaking by hindering sheet formation in the direct surroundings of the opening and thus forming a thinner place in the paper.
[0028] In accordance with a further embodiment, the security element can also be formed in a strip shape and extend over the total length or width of the security paper. This variant makes sense particularly when the security element is applied to the as yet uncut security paper in endless form. In this case the security element can be laminated on the security paper by a hot stamping technique in a continuous process.
[0029] The outline contour of the security element can be chosen at will. It can for example match the contour of the opening or be meaningfully related to a watermark surrounding the opening. Security element and watermark can also form a connected motif. Thus, the security element or opening and the watermark can together convey the impression of a stylized sun if the security element or opening is of circular form and the watermark areas are disposed radially around the opening.
[0030] The same applies analogously to the security feature applied in the area of the security element. For example, the security element can carry a print repeated in form of the watermark as a security feature.
[0031] The opening and/or the security element can be circular, oval, rectangular, trapeziform or also star-shaped. Any other outline contour is of course also possible.
[0032] If both sides of the opening are provided with a security element, the same, or the same type of, security element can be applied to both sides, or else different ones. The following combinations are preferred:
Side 1 Side 2 Self-supporting plastic film, possibly with Self-supporting plastic film, possibly with one or more security features; in label or one or more security features; in label or strip form or all over strip form or all over Self-supporting plastic film, possibly with Embossed foil element; in label or strip one or more security features; in label or form or all-over strip form or all-over Self-supporting plastic film, possibly with Coating or print consisting of a resin or a one or more security features in label or printing ink containing visually and/or strip form or all over machine testable substances (e.g. liquid crystal or interference layer pigments, luminescent substances); in label or strip form or all over
[0033] The inventive security paper can be further processed into any value documents, such as bank notes, shares, identity cards, credit cards, security labels, coupons, etc. It can also be used in the area of product protection for protecting any goods from forgery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Further advantages and embodiments will be explained with reference to the figures, in which:
[0035] FIG. 1 shows an inventive value document in a plan view,
[0036] FIG. 2 shows a section through said value document along A-A,
[0037] FIG. 3 shows an inventive apparatus for producing the inventive security paper,
[0038] FIG. 4 shows an inventive sealing element in accordance with detail B in FIG. 3 ,
[0039] FIG. 5 shows an alternative embodiment of the sealing element,
[0040] FIG. 6 shows detail B in accordance with FIG. 3 with additional screen embossing in the surroundings of the sealing element,
[0041] FIG. 7 shows a cross section through a security paper produced by the papermaking screen shown in FIG. 6 ,
[0042] FIG. 8 shows a plan view of the security paper section shown in FIG. 7 ,
[0043] FIG. 9 shows a further embodiment of the inventive security element in cross section along line A-A in FIG. 1 ,
[0044] FIG. 10 shows a further embodiment of the inventive security paper in cross section,
[0045] FIG. 11 shows a further embodiment of the inventive security paper in cross section,
[0046] FIG. 12 shows a further embodiment of the inventive value document.
DETAILED DESCRIPTION OF THE INVENTION
[0047] FIG. 1 shows an inventive value document in a plan view. The shown example involves a bank note 1 . Said bank note 1 has a through opening 2 . Said opening was produced during production of the security paper used for the bank note 1 and therefore has a fibrous, irregular edge 14 . Said edge 14 arises during sheet formation of the paper used for the bank note and cannot be produced by subsequently punching or cutting the paper.
[0048] FIG. 2 shows the bank note 1 in cross section along line A-A. This makes it clear that the opening 2 is a through opening.
[0049] FIG. 3 shows the schematic representation of a cylinder paper machine 3 as is preferably used for producing the inventive security paper 10 . The apparatus 3 consists essentially of the papermaking screen 4 and the take-off roll 5 on which the pickup felt 6 is mounted.
[0050] The papermaking screen 4 has sealing elements 7 which prevent sheet formation when the papermaking screen is dipped into the paper pulp 8 and thus produce the inventive openings 2 . The sealing elements 7 are so formed that they do not hinder removal of the paper web 10 in the area of the take-off roll 5 . Since at this time the paper web 10 is still very unstable and has low strength, a contact without tension must be ensured between the paper web 10 and the pickup felt 6 .
[0051] FIG. 4 shows detail B of FIG. 3 in an enlarged form. The sealing element 7 shown here is fastened to the surface of the screen 4 . It consists of a pot-shaped element with a further pot-shaped element embedded therein. The two elements are urged apart by a spring 9 so that they abut with their edge areas.
[0052] FIG. 5 again shows the sealing element 7 in the depressed state. The sealing element 7 is urged against the pressure of the spring 9 under the level of the papermaking screen surface 4 . The pressure is preferably produced by the take-off roll 5 . That is, the sealing element 7 is urged downward upon contact with the take-off roll 5 , thus in no way hindering the distortion-free removal of the paper web 10 by the pickup felt 6 .
[0053] FIG. 6 shows a further embodiment of the inventive papermaking screen 4 with reference to an enlargement of detail B of FIG. 3 . In this case the papermaking screen 4 additionally has a watermark embossing 11 in the surroundings of the sealing element 7 . In the shown example the watermark embossing 11 is disposed symmetrically around the sealing element 7 . However, any other embodiment of the watermark embossing 11 is also possible. The watermark embossing 11 causes the deposit of paper fibers in different thicknesses during sheet formation, so that the finished paper web is modulated in this area and shows the reflected/transmitted light effect typical of watermarks.
[0054] FIG. 7 shows a paper web 10 produced with the help of the papermaking screen 4 shown in FIG. 6 . Said paper web 10 has an opening 2 produced by the sealing element 7 . The modulated paper areas 12 , however, were produced by the watermark embossing 11 . Said paper areas hereinafter designated “the watermark 12 ” can be directly related meaningfully to the opening 2 , or the opening 2 and the watermark 12 can together form a motif, as shown for example in a plan view in FIG. 8 . The opening 2 has a circular outline form and is surrounded by a radial watermark 12 , resulting in the motif of a sun.
[0055] FIG. 9 shows a further embodiment of the value document 1 shown in FIG. 1 in cross section along line A-A. In this case the opening 2 is sealed by a security element 13 on one side. Said security element 13 is preferably disposed in a depression 15 surrounding the opening. Said depression 15 can be produced by subsequent calendering of the paper web 10 , i.e. by compression of the paper fibers.
[0056] Alternatively, the depression 15 can also be produced by an actual reduction of the paper thickness in this area. This is most simply done directly during production of the paper web 10 by performing sheet formation thinner in said area through a corresponding formation of the screen. This can be done by corresponding embossings 16 in the papermaking screen 4 .
[0057] The sealing element 7 shown in FIGS. 4 and 5 can be realized in a great variety of ways. It is thus likewise conceivable to realize it by a foamlike plug which is compressed by the take-off roll 5 . This element is glued to the papermaking screen 4 and likewise prevents sheet formation in this area. However, it can also be realized by a pot-shaped, elastic element which is compressed by pressure and then returns to the original form.
[0058] The security element 13 can be of single- or multilayer form and has at least one paper or plastic layer. The security element 13 preferably has in the area of the opening 2 a relatively large transparent area which serves as copy protection, on the one hand, and makes the opening edge recognizable from both sides, on the other hand. Furthermore, the security element 13 can be provided with any desired security features.
[0059] FIG. 10 shows a further embodiment of the inventive security paper in cross section. The paper web 10 has an area 16 with a smaller paper thickness in comparison with the rest of the paper web. However, paper thickness is almost uniform throughout the area 16 . This thin area 16 can be produced by corresponding screen embossing or freeness hindrance during production of the paper web 10 . In said thinner area 16 the inventive opening 2 is subsequently provided. The edge contours 17 of the opening 2 are indicated by dashed lines in FIG. 10 . The opening 2 is preferably produced in this embodiment by subsequent punching or cutting of the paper web in the area 16 . It must at the same time be ensured that the area 16 protrudes beyond the opening 2 at least in a partial area to permit a corresponding check of the authenticity of the paper web 10 to be performed upon transmissive viewing.
[0060] FIG. 11 shows a further embodiment of the inventive security paper, whereby the security paper in this case consists of two paper layers 18 , 19 . The two paper layers 18 , 19 are produced on separate cylinders and combined directly after removal from the papermaking screen and then further processed jointly. In the first paper web 18 a hole 20 is produced with the above-explained aids during sheet formation on the cylinder. When the two paper webs 18 , 19 are combined, said hole 20 is sealed again on one side. After completion of the security paper the inventive opening 2 is provided in the second paper web 19 . The edges 17 of the opening 2 are also shown by dashed lines in this figure. The opening is produced here by cutting or punching, whereby it must be ensured analogously to the embodiment shown in FIG. 10 that the edges 17 or cut edges of the opening 2 are located in the area of the hole 20 .
[0061] FIG. 12 shows a further embodiment of the inventive value document 1 in a plan view. The opening 2 is composed in this example of several partial openings 21 , 22 , 23 separated from each other by paper bars 24 . Said partial openings 21 , 22 , 23 can be produced analogously to the above-described variants for the opening 2 . | A security paper for producing security documents, such as bank notes, identity cards or the like, having at least one opening, whereby the opening is produced during papermaking and does not have a sharp limiting edge in the edge area. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to the field of telemetric, biomedical devices, and, in particular, to telemetric systems for the tranmission of electrocardiographic (ECG) signals from a remotely located patient to a central receiving station.
DESCRIPTION OF PRIOR ART
Care of the critically ill patient has substantially improved over the last few years due largely to an increased ability to continuously monitor the patient's condition and to take immediate corrective action in order to anticipate distress or trauma and take a proactive action. Moreover, the continuous monitoring of a critical patient discloses symptoms which can be detected only through a period of prolonged and careful observation or by observation of short periods of dysfunction which unpredictably occur. In any case, the quality of care for the critical patient has become increasingly dependent upon a continuous ability to monitor such patients.
In order to effectuate critical care, wards have been set up within hospitals with personnel and equipment trained and adapted to monitor the vital signs of patients and to take appropriate responsive action. In the case of critical cardiac patients, such critical care includes the continuous monitoring of the ECG signals from each patient as well as the performance of an implanted pacemaker within the patient. The continuous monitoring of multiple patients at a central nursing station has thus become necessary and equipment has been devised in the prior art for providing a telemetric link between each patient in the ward and the central station. However, the nature of the pacemaker signal and the ECG signals is substantially different from each other. Typically, a pacer signal ranges in amplitude from a few millivolts to several hundred millivolts and may be of 50 microseconds to 2 milliseconds in duration. In contrast, the QRS complex of the human heart ranges in amplitude from 0.5 millivolts to 5 millivolts as detected at the patient's skin electrodes. Inherent bandwidth restrictions in the telemetry circuitry in the prior art have caused the transmission of the pacer pulse to become unacceptably distorted, mainly due to pulse stretching. It has become increasingly important in critical care patients to be able to accurately compare the actual pacer pulse to the heart performance as defined by the ECG signal. When the telemetry distorts the pacer pulse, it becomes virtually impossible at the receiving station to perform the necessary analysis to correlate the pacer's performance with the patient's heart.
In order to overcome this defect, prior art cardiac telemetric units have increased the bandwidth of the entire telemetry link in order to accommodate the pacer pulse. However, the results obtained by this solution have been unsatisfactory since an increase in bandwidth causes a severe degradation in the system's signal-to-noise ratio. Moreover, the greater the increase in bandwidth, the fewer the number of channels that can be accommodated on the assigned frequency band. Therefore, the number of patients who can be monitored by such a system has decreased in the face of increasing demand by physicians to make such critical care available to more and more patients within a hospital. Finally, increasing the bandwidth of the telemetry link substantially increases the cost of such a system, again in the face of mounting pressures to provide sophisticated in state-of-the-art medical care at the lowest possible cost.
Data provided into the telemetry link is ultimately derived through skin contacts placed on the patient which pick up both the pacer pulse and the ECG complexes. The quality of the signal, which in circumstances can be transmitted, is thus initially dependent upon and assumes a satisfactory skin contact with the patient. Quite commonly, and particularly over the course of time, one or more of the skin contact electrodes may loosen or its signal pick-up may otherwise degrade. This is generally denoted as a "loose lead" condition. In order to detect this loose lead condition, the prior art has devised circuitry whereby a high frequency signal, much higher than the ECG signals, is placed across the leads. As long as the lead contact is adequate, the high frequency signal is generally shunted through the patient and very little, if any, high frequency voltage would appear across the leads. However, upon the occurrence of a loose lead condition, the impedance between the leads increases and therefore the high frequency voltarge differential between the leads increases and becomes observable.
While this prior art method for detecting a loose lead condition is suitable in the case where the high frequency signal used for detecting the loose lead condition is several times higher than the frequency of the ECG complex, the prior art method becomes unacceptable and inadequate when it is also desired to monitor the pacer pulse. The frequency components of the pacer pulse are substantially greater than ECG signal and thus tend to interfere with the higher frequency loose lead signals. Thus, under the prior art methods, it has become impossible to both monitor a loose lead condition and to monitor the pacer pulses.
What is needed then is a cardiac telemetric system which is capable of transmitting the ECG wave forms and pacer pulses from a plurality of patients to a central station in such a manner that the loose lead condition can continue to be monitored without interference of either the detection of the pacer pulses or the ECG wave forms. What is described below is a system capable of providing this performance and capable of overcoming each of the above discussed deficiencies of the prior art systems.
BRIEF SUMMARY OF THE INVENTION
The present invention is a circuit for transmission of a physiological signal characterized by a first component signal within a first frequency band such as an ECG signal, and further characterized by a second signal within a second higher frequency band such as a pacer pulse. The circuit comprises electrode leads for receiving the physiological signal including the first and second component signals. A pulse limiter is coupled to the electrode leads. The pulse limiter generates a frequency modulated output signal indicative of the first component signal of the physiological signal. The pulse limiter is characterized by a limited slew rate wherein the second component signal and the physiological signal is substantially deleted from the output signal of the pulse limiter.
The invention also comprises a circuit for generating a signal indicative of faulty electrode contacts on a patient. The circuit comprises electrodes coupled to the patient which electrodes receive a physiological signal from the patient. Leads are coupled to the electrodes and communicate the physiological signals from the electrodes. A fixed frequency generator, typically operating at approximately 60 Hz generates a loose lead signal with a fixed frequency which is within the frequency spectrum of the physiological signal. The fixed frequency generator is coupled to the leads so that the loose lead signal generated by the fixed frequency generator is substantially shorted across the electrodes through the patient when the electrodes make suitable contact with the patient and when the loose lead signal tends to be open circuited across the leads when the electrodes fail to make suitable contact with the patient. The circuit of the invention then includes a subcircuit for detecting when the loose lead signal has achieved a predetermined magnitude across the leads which is indicative of inefficient electrode contact with the patient. The subcircuit discriminates the loose lead signal from the physiological signal and thus detects the loose lead condition without interference from reception in the subcircuit of the physiological signal from the patient. The circuit for detecting the loose lead signal comprises a transmitter and a receiver. The transmitter includes a pacer pulse limiter circuit which passes the loose lead signal and physiological signal. The physiological signal is characterized by a first component signal lying in the first frequency band and characterized by a second component signal within a second higher frequency band. The loose lead signal also lies within the first frequency band. The pacer pulse limiter circuit separates the second signal from the first signal and loose lead signal.
The invention also includes a method for monitoring and communicating a physiological signal which signal is characterized by a first portion within a first frequency bandwidth, such as an ECG signal, and is characterized by a second portion within a second higher frequency bandwidth, such as a pacer pulse. The method comprises the steps of receiving the physiological signal from the patient and separating the first and second portions of the physiological signal within the pacer pulse limiter, which generates a slew limited proportional pulse width output. The first and second portions of the physiological signal are then communicated as noninterfering components of an output signal. By reason of this combination of steps, a second portion of the physiological signal which is within the higher frequency bandwidth is received and communicated independently of the first portion of the physiological signal which is within the first frequency bandwidth. Thereby, independent signal handling and processing is both possible and practical. The step of separating is particularly characterized by slew limiting a proportional pulse width output generated in response to the physiological signal whereby the second portion within the second higher frequency bandwidth is effectively separated or removed from the output signal.
These and other embodiments of the present invention can be better understood by now turning to the following Figures wherein like elements are referenced by like numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is diagrammatic block diagram of a transmitter according to the invention.
FIG. 2 is a diagrammatic block diagram of a receiver devised according to the invention.
FIG. 3 is a more detailed schematic of a portion of the transmitter shown in FIG. 1.
FIG. 4 is a block diagram of the remaining portion of the transmitter shown in FIG. 1.
FIG. 5 is a somewhat more detailed schematic of an alarm oscillator included as part of the transmitter illustrated in FIG. 1.
FIG. 6 is a somewhat more detailed block diagram and schematic of a portion of the receiver of the invention illustrated in FIG. 2.
FIG. 7 is a block diagram of the remaining portion of the receiver illustrated in FIG. 2.
To better understand the invention and its illustrated embodiment in connection with the above schematics, turn now to the following detailed description.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is a cardiac telemetric system capable of transmitting pacer pulses and ECG wave forms from a plurality of critical care patients to a central receiving station while maintaining and testing for a loose lead condition on each patient. The invention allows such a system to be devised while maintaining an adequate signal-to-noise ratio, without reducing the number of available transmitting channels within an assigned frequency bandwidth and without substantially increasing the cost of manufacture of such a system.
Before turning to the detailed description as illustrated in the figures described above, consider first a general description of the invention's functions and attributes. The invention utilizes a novel method of transmitting both the pacer pulses and ECG wave forms by combining an FM-FM and direct FM signal on a single radio frequency carrier. The composite signal from the patient, which contains both the ECG wave form and the pacer pulse, is first amplified by a low gain differential amplifier. The slew rate limiting of the pacer pulse is proportional to its pulse width and then results in the deletion of most of the pacer pulse from the composite signal. Just enough of the pacer signal remains in the composite signal to indicate the polarity of the pacer pulse. The composite signal is then AC coupled and amplified through a high gain, narrow bandwidth amplifier. The ECG wave form is used to modulate a subcarrier oscillator. The subcarrier oscillator then frequency modulates the output of a radio frequency oscillator resulting in an FM-FM modulation which carries ECG information. A second output from the differential amplifier, upstream from the slew rate limiter of the pacer is provided for the pacer pulse channel. A filter is used to eliminate the ECG complex, and a detector and pulse shaper constructs a pulse flag of fixed amplitude, duration and polarity. The pulse flag is used to directly frequency modulate the radio frequency oscillator in the transmitter. Modulation of the radio frequency by the ECG complex and the pulse flag thus becomes mixed.
The direct FM and FM-FM signal is then transmitted to a receiving unit. The composite transmitted signal is separated at the receiver FM detector output. The pacer flag is recognized by the use of a peaked low pass filter followed by a peak detector, comparator and one shot multivibrator. The ECG component is demodulated using a phase-lock-loop demodulator which detects only the signal frequency modulating the subcarrier.
The loose lead condition is detected by the invention by using a low frequency AC voltage or current generator capacitively coupled to the patient's skin electrodes. An AC frequency detector is used after a low pass filter in the receiver to determine when a predetermined level of low frequency AC signal appears at the ECG leads. The level of this low frequency signal is proportional to the ECG patient lead resistance. The AC frequency is coupled to the electrodes through a resistance many orders of magnitude greater than the normal ECG lead resistance of the patient. Therefore, as long as good contact is maintained, no significant distortion of the ECG signal occurs. However when a loose lead contact begins to develop, the AC frequency will appear at the electrode and be detected at a preselected level.
The invention now having been generally described, turn now to the block diagram of FIG. 1 wherein a transmitter is diagrammatically depicted and to the block diagram of FIG. 2 wherein a patient receiver is diagrammatically depicted.
In FIG. 1, the transmitter, generally denoted by reference numeral 10, is comprised of a differential amplifier 12 having its inputs coupled to electrodes 14 and 16. Electrodes 14 and 16 are the ECG patient electrode, skin contacts which pick up the composite signal including the ECG wave form and the pacer pulse. The composite signal is generated as an output from differential amplifier 12 and coupled through a first path as an input to a pacer pulse limiter 18. Pulse limiter 18 attenuates the pulse, the pulse output amplitude which is proportional to the input signal width. By limiting, the slew rate of pacer pulse limiter 18, the high frequency components, corresponding to the pacer pulse within the composite signal provided at the input of limiter 18, are substantially attenuated and eliminated from the composite signal. Therefore, most of the information provided in the output of limiter 18 represents the ECG waveform and only enough of the low frequency contents of the pacer pulse is present in the output of limiter 18 to indicate the polarity of the pacer pulse. The output of limiter 18 is provided as an input to a subcarrier oscillator 20. In the illustrated embodiment, subcarrier oscillator 20 operates at a frequency of approximately 3180 Hz and generates an output which is frequency modulated by the output of limiter 18. The frequency modulated output of subcarrier oscillator 20 is then amplified through a high gain, narrow band amplifier 22 and summed at node 24. Node 24 is coupled to the input to a voltage controlled oscillator 26.
Meanwhile, the composite signal from the output of differential amplifier 12 is also provided as an input to a pacer detector 28. Thus, the composite signal is provided along a second path, the first path being provided as an input to limiter 18 and the second path provided as an input to pacer detector 28. The gain of amplifier 12 is set low enough to accommodate the full range of signal amplitude expected for the pacer pulse. Pacer detector 28, includes a 1 kilohertz bandpass filter which removes substantially all of the ECG waveform from the composite signal. The output of the bandpass filter included within detector 28 is amplified and provided as an input to a one-shot multivibrator 30. The output of multivibrator 30 is a pacer flag of a predefined amplitude, duration and polarity which is generated whenever a signal of sufficient amplitude, indicative of a pacer pulse is provided at its input. The output of multivibrator 30, the pacer flag, is then summed at node 24 with the frequency modulated subcarrier signal, both of which are simultaneously provided as inputs to voltage controlled oscillator (VCO) 26. Voltage oscillator 26 is a conventional VCO with a crystal controlled output of approximately 50 megahertz. The output of VCO 26 is quadrupled by multiplier 32 to approximately 200 megahertz. The output of multiplier 32 is coupled through a conventional band pass filter 34 and then capacitively coupled to a radio frequency antenna 36.
Return now to FIG. 1. The system's battery voltage, generated by a conventional battery 38, is monitored by a battery detection circuitry 40. Battery detection circuitry 40 will generate a 300 hertz signal whenever the voltage battery 38 falls below a preselected magnitude. A remote switch 42, accessible to the patient, is used to generate a 240 hertz signal which can be used either as an event marker by the patient, a nurse call button, and a calibration signal. Finally, the low frequency loose lead signal is capacitively coupled to electrodes 14 and 16 through proximity capacitor 48 presenting a very high impedance to provide a low frequency AC signal indicative of a loose lead connection. Wire 44 is coupled to lead 14, for example, through a low capacitence AC coupling 48, which may in fact be the simple juxtaposition of wire 44 disposed and maintained in the proximity of electrode wire to electrode 14. These three signals, the 300 hertz low battery signal from detector 40, the 240 hertz remotely activated signal coupled through switch 42 are each provided as outputs from an alarm oscillator 50. The alarm oscillator 50 is coupled to the input of band pass filter 22. Thus, a low battery detector signal, and the remote activation signal are additionally provided to node 24 and are used to directly frequency modulate the transmitted RF signal. It should be noted that each of these signals are near the frequency bandwidth of the ECG wave form and are superimposed low frequency signal modulation, whereas ECG wave forms are carried on the 3,180 hertz subcarrier frequency which is used to FM-FM modulate the radio signal. Therefore, the interference in the transmitted signal between these alarm signals and the ECG wave form is insignificant.
Before discussing other features of the transmitter 10 in FIG. 1, turn momentarily to the schematic diagram of FIG. 2 wherein a receiver of the invention is illustrated. The transmitted radio frequency signal from transmitter 10 in FIG. 1 is received by an antenna generally denoted by the reference numeral 52 in FIG. 2. The radio signal is amplified by a conventional radio frequency amplifier 56 and then provided as an input to a conventional mixer 58. A local crystal controlled oscillator 60 is provided as the other input to mixer 58 to hetrodyne the RF signal down to approximately 10.7 MHZ. The output of mixer 50 is then provided to a conventional crystal filter 6 which in turn passes the intermediate frequency of approximately 10.7 Mhz. The intermediate radio frequency is amplified by IF amplifier 64 whose output in turn is coupled to an input of a conventional crystal controlled discriminator 66 operating at the intermediate frequency of 10.7 Mhz. The output of crystal discriminator 66 thus includes the pacer pulse, the ECG waveform, and various alarm signals discussed below, including the loose lead alarm signal. At this point, at the output of crystal discriminator 66, the alarm signals are demodulated while the loose lead alarm signal and ECG waveform continue as FM modulation of the 3180 hertz subcarrier. The alarm signals are split from the subcarrier by circuitry described in greater detail below in connection with FIG. 7, which is symbolically included within crystal discriminator 66 in schematic FIG. 2, while the subcarrier signal is coupled to a second subcarrier demodulator 68 which performs a second FM demodulation to strip off the ECG waveform and loose lead signal from the subcarrier. These two signals in turn are separated by circuitry included in ECG discriminator 68 and described below in greater detail in connection with FIG. 7. These signals are later processed to detect the loose lead condition and to present the ECG signals available at the output of discriminator 68 as an analog signal. The pacer signal is reconstructed from output 70 of discriminator 66 in a pacer detector circuit 76.
Meanwhile, the fully demodulated alarm signals are generated at output 70 of discriminator 66 and provided and separated at the inputs of respective detector circuitry as depicted in FIG. 2, labelled generally as alarm logic section 71. The transmission and reception of the pacer pulse signal and ECG waveform have now been traced through the circuitry of FIGS. 1 and 2. However, as mentioned above, in addition to these signals, there are a plurality of alarm signals such as the loose lead signal, remote call, weak RF alarm and low battery alarm signals. First consider how each of these alarm signals are generated in the transmitter and then detected in the receiver.
Consider now the reception and detection of these alarm signals in FIG. 2. The low battery 300 hertz signaal and the remote call 240 hertz signal are separated in FIG. 2 from the other alarm signals by an alarm low pass filter described below in greater detail in FIG. 7 and separately detected in FIG. 2, in tone detector 72 in the case of the remote record 240 hertz signal, and tone decoder 74 in the case of the low battery 300 hertz signal. The pacer pulse is similarly separated by an appropriate low pass filter and detected by a pacer flag detector. The triggering of detector 76 causes then reconstruction of the pacer flag by a one-shot multivibrator, all of which is symbolically included and denoted as pacer detector 76. Finally, an output is taken directly from RF amplifier 64 simply to detect whether or not an RF signal, whether it be modulated or not, is being transmitted and received. In the event that an RF signal is not being received, a weak signal detector 78 coupled to RF amplifier 64 is activated to produce an appropriate alarm.
The above description in connection with FIGS. 1 and 2 has broadly described the transmitter and receiver and has assumed throughout the discussion that a single pair of leads from a single patient was monitored. It is clearly within the scope of the invention and is contemplated within the preferred embodiment that each patient's transmitter and receive channel will be arranged and configured to carry a plurality of lead pairs. Generally, two pairings of three electrodes is used in cardiac monitoring. In that case, in FIG. 1 the ECG amplifier broadly comprising differential amplifier 12, limiter 18, subcarrier oscillator and band pass filter 22 is duplicated for the second pair of leads. The remaining portions of the circuitry as illustrated in FIG. 1 are shared in common between the two electrode pairs. In addition, it is only necessary for pacer detector 28 to pick up the pacer pulse from only one of the pair of electrodes. Therefore, the transmitter in FIG. 1 can be easily expanded to include two or more additional electrode pairs by providing a differential ampliifier, limiter, subcarrier oscillator and bandpass filter in parallel to those illustrated, which circuits would then operate at a distinguishable subcarrier frequency. Each of the channels are summed at node 24 and transmitted in common modulation through the remaining stages of the FM transmitter. Similarly, in the receiver, a second ECG discriminator similar to discriminator 68 is provided for the second pair of electrodes, the information from which is transmitted at the second subcarrier frequency. FIG. 2 is thus modified by simply providing a second ECG discriminator in parallel to discriminator 68.
Turn now to FIG. 3 wherein a more detailed schematic of the transmitter is illustrated. Patient leads 14 and 16 are shown as resistively coupled to inputs of a differential amplifier 12. The 60 hertz loose lead signal, generated by means described below, is coup1ed to input 14 through a loose capacitive coupling 48. The ECG signal, loose lead 60 hertz signal, and pacer signal are thus provided across the inputs of differential amplifier 12. The signal from electrode 14 is filtered by passive RC filter, generally denoted by reference numeral 80, and as will be discussed below, is provided to the input of a pacer detection circuitry 28.
Meanwhile, the output of differential amplifier 12 is coupled to one of the inputs of a slew limiter 82. The output of slew limiter 82 is a signal having a pulse amplitude proportional to the pulse width of differential output 12. The slew rate of amplifier 82 is such that it is unable to respond to the higher frequency components which are generally indicative of the pacer pulse, but is able to respond to the 60 hertz loose lead signal and the low frequency ECG signals. The output of amplifier 82 is capacitively coupled through capacitor 86 to a buffer 88. In addition to signal conditioning, buffer 88 is an active half-hertz filter which removes any very low frequency drift. A calibration remote call signal is also coupled from a 6 volt supply through push button switch 42 and a passive resistive network generally denoted by reference numeral 92, which is coupled to one of the inputs of buffer 88 to cause a calibration signal to be coupled to its output. The output of isolator 88 is coupled through a resistive network, generally denoted by reference numeral 94, to the input of a subcarrier oscillator deviation circuit 96. In the preferred embodiment, circuit 96 generates an oscillatory output proportional to the voltage at its input 98 of approximately 60 hertz per millivolt. The output of oscillator 96 is coupled to a subcarrier oscillator chip 98, such as type MC-14046 PCB, which generates a frequency modulated subcarrier oscillator of approximately 3180 hertz. Therefore, the loose lead signal and ECG signals deviate at the output 100 of chip 98 at the subcarrier oscillator frequency of 3180 hertz. The high frequency pacer pulse signal is separated by a slew limitation of slew limiter/amplifier 82. Thus, the circuitry comprised of circuits 82 and 88 and associated components of FIG. 3 generally correspond to pacer pulse limiter 18 of FIG. 1, while subcarrier oscillator 20 of FIG. 1 corresponds to circuitry 96 and 98 of FIG. 3.
Turn now to FIG. 4 wherein the FM signal from output 100 of chip 98 is coupled through a summation filter generally denoted by reference numeral 102 and 104. These circuits serve to filter out any signals extraneous to the 3180 hertz modulated subcarrier.
Meanwhile, the pacer pulse from the output of filter 80 in FIG. 3 is coupled to a one kilohertz high pass filter generally denoted by reference numeral 106 in FIG. 4. The lower frequencies associated with the ECG signals and loose lead signals are thus attenuated by high pass filter 106, which generates a pulse indicative of the pacer pulse. The output of high pass filter 106 in turn is amplified by amplifier 108 and the signal generally conditioned to be provided as an input to a one-shot multivibrator, generally denoted by reference numeral 30. The output of one-shot multivibrator 30 is a 40 millisecond square wave pulse which is generated whenever a signal of sufficient magnitude is coupled to its input 110. The output of one-shot 30 is capacitively coupled to one input to a gate 112. Gate 112 simply provides for signal buffering and conditioning. The output of gate 112 is thus a 1 millisecond square wave corresponding to the 40 millisecond square wave of the output of one-shot 30. The output of gate 112 is thus coupled through a diode 114 to node 24. As described in connection with FIG. 1, node 24 is also coupled to the output of band pass filter 22. The signal at the output of band pass filter 22 is the filtered FM modulated ECG and loose lead signal ultimately originating from differential amplifier 12. The signal at node 24, consisting of the algebraic addition of the pacer pulse signal coupled through diode 114 and the filtered FM modulated 3180 hertz signal from bandpass filter 22, is then coupled through a conventional voltage controlled oscillator 26, multiplier 32, bandpass filter 34 and RF antenna 36 as described and depicted in connection with FIG. 1. The transmission in the preferred embodiment is approximately 200 Mhz and frequency modulates signal corresponding to the pacer pulse and an FM-FM signal corresponding to the loose lead and ECG signal.
Turn to FIG. 5 which shows the loose lead, low battery remote activation subcarrier oscillator. The alarm oscillator 50 generally shown in FIG. 5 is comprised of a two stage oscillator including first stage 116 and second stage 118. Together circuits 116 and 118 including associated passive circuitry as shown in FIG. 5 constitute a selectively controlled alarm oscillator. Normally, the output of second stage 118 is a 60 hertz signal. This is the loose lead signal which is coupled through a passive 60 hertz lowpass filter generally denoted by reference numeral 120, and then loosely capacitively coupled through a juxtapositioned wire symbolically denoted as capacitor 48 in FIGS. 1 and 3. The 60 hertz output from second stage 118 is typically set through a variable resistor 122 in the feedback loop between first and second stages 116 and 118. However, by varying the voltage applied to node 124 in the feedback loop of first stage 116, the output of the alarm oscillator 50 and in particular, second stage 118 can be varied depending on the voltage applied. For example, a 6 volt signal coupled through push button 42 as shown in FIG. 3 is coupled through diode 126 and resistor 128 to node 124 to inject a voltage which will cause alarm oscillator 50 to generate a 240 hertz output signal. The signal frequency chosen is arbitrary and many other equivalent frequencies could have been equivalently substituted. However, 240 hertz is the frequency selected in the preferred embodiment.
Similarly, the battery which powers the patient unit is coupled to a conventional voltage regulator diagrammatically depicted by reference numeral 130 in FIG. 5, whose output in turn, is coupled to a low battery detection circuit generally denoted rby reference numeral 132. When the output of regulator 130, following the output of the battery, reaches a predetermined voltage, detection circuit 132 is turned on and coupled through gate 134. The output of gate 134 in turn is coupled to a protection diode 136 and resistor 138 to node 124 in feedback loop of first stage 116. Due to the resistive values and voltages chosen, a second distinguishable voltage will be impressed upon node 124 in alarm oscillator 50, and in particular, the output of second stage 118 will be caused to generate a 300 hertz signal. Thus, the 300 hertz signal in the preferred embodiment is indicative of a low battery condition. Neither one of these signals are able to pass through lowpass filter 120, but both of them are coupled from the output of first stage 116 to one input of a driver circuit 146. Driver circuit 146, in turn is activated by the voltage from push button 42 or gate 134 through diode 142 and 140, respectively, and a resistive network, generally denoted by reference numeral 144, which is coupled to the other input of driver 146. Driver 146 thus being enabled then buffers and amplifies the 240 or 300 hertz signal from the alarm oscillator and provides that signal and its output to the input of bandpass filter 102. From the input of bandpass filter 102, the 240 hertz remote call signal or the 300 hertz battery signal is treated in an identical manner to the FM modulated signal from output 100 of chip 98. Thus, when either of these signals is active they ultimately are FM modulated along with the pacer pulse in the 200 Mhz signal broadcast through antenna 36.
The transmission circuitry now having been described, turn now to the detailed schematics of the receiver which has previously been generally described in connection with the block diagram of FIG. 2. Turn to FIG. 6. The RF signal, generated by the circuitry described above, is received by antenna 52 shown in FIG. 2 and is coupled to a conventional RF amplifier 56. The receive signal in the preferred embodiment is in the range of 174 to 216 megahertz. The output of RF amplifier 56 in turn is coupled to a conventional mixer 58 where it is mixed with the output signal of a crystal controlled local oscillator 60. The output of mixer 58 is coupled through a conventional 8 pole 20 kilohertz bandpass filter 62 tuned to 10.684 megahertz. The intermediate frequency of 8 pole filter 62 in turn is coupled to the input of a conventional intermediate frequency discriminator 67, such as type CA 3l89E. Discriminator 67 is a modular chip, which includes an intermediate frequency amplifier shown as amplifier 64 in FIG. 2, which in turn is coupled to a level detector and tuning meter circuit all included in circuit 67. The output of the tuning meter circuit within the modular circuit 67 is indicative of the strength of the RF signal being received. This voltage is compared against an arbitrarily adjusted reference voltage from resistive network 150 within a detector amplifier 152. The output of amplifier 152 is then coupled to an RF detector described in greater detail below.
Discriminator circuit 67 demodulates the intermediate frequency thereby producing at its output the FM modulated 3180 kilohertz subcarrier frequency, the pacer pulse signal, low battery and remote call signal. The loose lead and ECG signal remain FM modulated on a 3180 kilohertz subcarrier. The output of discriminator 67 is thus coupled through a passive filter network, generally denoted by reference numeral 154, to the input conventional buffer amplifier 156. The output of buffer amplifier 156, in turn, is coupled through the input of a conventional 5 kilohertz low pass filter, generally denoted by reference numeral 158 in FIG. 7. The high frequency pacer pulse is thus effectively removed by low pass filter 158. The output of low pass filter 158 is coupled to the input of a conventional active high pass 1.3 kilohertz filter 160. Filter 160 thus serves to separate the 300 and 240 hertz alarm signals, but still allows the 3180 kilohertz signal to easily pass through. Filters 158 and 160 thus form a frequency window through which only the frequency modulated 3180 kilohertz signal, bearing the ECG and loose lead information can pass. The output of high pass filter 160 is then coupled to a conventional subcarrier phase-lock-loop demodulator, such as type XR2211, denoted by reference numeral 162. The output of demodulator 162 is thus a signal representative of the ECG and loose lead signals. Superhetrodyned harmonics or high frequency signals are then removed by coupling the output of demodulator 162 to a conventional low pass filter 164. The output of low pass filter 164 in turn is then filtered again by a conventional active low pass filter 166 which will remove signal at or above 110 Hz. The output of low pass filter 166 is coupled to a conventional output buffer 168 which conditions the ECG signal and presents it as an analog output suitable for CRT or chart display.
Meanwhile, the output of low pass filter 164 is also coupled to a conventional 55 hertz bandpass filter 170 which filters out the ECG component and passes the loose lead signal. The output of bandpass filter 170 in turn is coupled to a conventional voltage level detector 172, which measures the transmitted 60 hertz signal indicative of a loose and compares it against a reference voltage, arbitrarily selected from resistive network generally denoted by reference numeral 174. If a sufficient magnitude loose lead signal is detected, loose lead detector 172 generates a 60 hertz output which is coupled to the input of a conventional tone detector generally denoted by reference numeral 176. Tone detector 176 is a modular circuit, such as type LM 567N which generate an active low signal in response to detecting a 60 hertz signal. Tone detector 176 in the preferred embodiment includes a pair of parallel tone detectors, one set for 58 hertz and the other set for 60 hertz in order to reliably detect the loose lead signal whose frequency as received may vary by a few percent. The output of tone detector 176 may be used as an alarm disable signal as well as an active low, lead-off signal to disable the active low low-battery, remote activate, and pacer flag outputs as well.
Consider the output of buffer amplifier 156, in addition to being coupled to a low pass filter 158 to ultimately generate the ECG analog signal, is also coupled to an alarm low pass filter 178 in FIG. 7 which separates out the higher frequency components corresponding to the pacer pulse. The 300 hertz signal and 240 hertz remote activation signal are passed by a conventional active low pass filter 178 which has its output capacitively coupled to a modular, low battery tone detector 180 and a modular remote activate tone detector 182. Each of these circuits are modular circuits for detecting a specified tone frequency, such as modular types LM 567N, and are respectively tuned to 300 hertz and 240 hertz. The active low output signal which is generated is coupled to provide the low battery and remote activate output signals.
The output of buffer amplifier 156 is also coupled to a conventional low pass filter 184 in FIG. 7. Low pass filter 184 is set to pass the frequency components of the pacer pulse or lower and to filter out all higher harmonics and frequencies. Filter 184 has its output and turn coupled to a pacer tag detector which monitors the output of filter 184 for a level of a predetermined magnitude. Once a signal with a magnitude of the pacer pulse is detected, detector 186 generates an active low output which in turn is coupled to a conventional one shot generator 188. Generator 188 generates an active low, 10 millisecond, square wave pulse thereby reconstructing the pacer pulse. This pulse is subsequently made available as an output signal.
However before turning to the available output signals, redirect your attention again to the RF detection signal as shown and described in connection with circuitry 148 of FIG. 6. The output of detector 152 is coupled through a diode 190 to a node 192 which in turn is coupled through resistor 194 to ground. Node 192 is also coupled through a diode 196 in FIG. 7 to a RF/NIB detect circuitry, generally denoted by reference numeral 198. Detection circuitry 198 generates as its output an RF/NIB fail active low signal which is provided as a system output signal to indicate either a weak RF signal or failure to remain in the band of phase lock loop demodulation. A pull-up resistor 198 maintains node 200 at or near the supply potential. Node 200 is coupled to a level detector 202 whose other input is maintained at a reference by a passive resistive network 204. The output of level detector 202 is active low and thus is generally in a low state, thereby maintaining the potential at node 206 low. Node 206 is coupled to one input of a level detector 208 whose other input is similarly coupled to the reference voltage from voltage divider 204. As a result, the output of detector 208, which is also active low remains high, that is the RF/NIB fall signal, remains inactive high.
However, when an insufficient RF signal is received, diode 190 (FIG. 6) will be reversed biased and caused to not conduct. Node 192 will thus be pulled low to a point determined by the relative ratios of resistor 194 (FIG. 6) and 198 (FIG. 7). In the preferred embodiment, resistor 194 is 470 ohms while resistor 198 is 10 Megohms, thus the potential at node 200 is near ground. This causes detector 202 to cease conducting thereby allowing the voltage supply to pull node 206 high through resistor 210. This, in turn, causes detector 208 to conduct and its output to thus be driven active low.
Node 200 is also coupled to subcarrier phase lock loop demodulator 162. More specifically, node 212 is coupled through diode 214 to the lock detection output of modular circuit 162. Normally, diode 214 is reversed biased through the voltage supply through resistor 216. However, when the lock detection circuit goes active low diode 214 becomes forward biased through the voltage supply through resistor 198. This causes node 212 to go toward ground. Again, as the normally high state at node 200 is driven to ground, the output of detector 208 goes active low. This then indicates either a failure to receive the RF signal or to modulate it in the first stage, or a failure to make an adequate second demodulation in circuit 162.
Many modifications and alterations may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. For example, although the detailed schematic has been described in terms of a single electrode pair, it is entirely within the scope of the invention that multiple electrode pairs can be accommodated by duplicating the appropriate portions of the circuitry,. More specifically in the receiving unit, subcarrier phase-lock-loop demodulator 162, low pass filter 164, band pass filter 170 and level detector 172 rwould be duplicated for the second pair of leads and would operate at a distinguishable subcarrier frequency. Similarly, low pass filter 166 and output buffer 168 would be duplicated for the ECG output of the second pair of leads. In addition thereto, what has been decribed above, is a transmitter and receiver for a single patient. Clearly, multiple patients can be multiplexed by extending the teachings of the above description in a manner well known to the art.
Therefore, the illustrated embodiment, which has been described, has been set forth only for the purposes of example and clarity and should not be taken as limiting the invention as rdefined by the following claims. | The invention is a telemetric biomedical system for simultaneously transmitting a pacer pulse together with lower frequency ECG wave forms and a loose lead signal. The loose lead signal is a low frequency signal applied across the skin electrodes which are attached to a patient subject to cardiac monitoring. In the event that such electrodes should become detached or poorly coupled to the patient, the loose lead signal tends to become open circuited across the leads and can be detected. The loose lead signal and ECG wave form since from the patient, is transmitted in an FM/FM modulated signal, while the pacer pulse is separated from the ECG wave form prior to amplification and is simultaneously transmitted as an FM modulated signal. In addition thereto, various alarm signals are transmitted as FM modulated signals with the pacer pulse. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/033,164, filed on Mar. 3, 2008. The disclosure of the above application is incorporated herein by reference.
FIELD
The present disclosure relates to limiting wheel slip of a vehicle, and more particularly to controlling the engine to limit wheel slip.
BACKGROUND
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1 , a functional block diagram of an engine 102 and exhaust system 106 for a vehicle is presented. The engine 102 combusts a mixture of air and diesel fuel to produce torque. The resulting exhaust gas is expelled from the engine 102 into the exhaust system 106 . The exhaust system 106 includes an exhaust manifold 108 , a diesel oxidation catalyst (DOC) 110 , a reductant injector 112 , a mixer 114 , and a diesel particulate filter (DPF) assembly 116 .
The exhaust gas flows from the engine 102 through the exhaust manifold 108 to the DOC 110 . The DOC 110 oxidizes particulate unburned hydrocarbon in the exhaust gas as the exhaust gas flows through the DOC 110 . The reductant injector 112 may inject a reductant, such as ammonia or urea, into the exhaust system 106 . The mixer 114 , which may be implemented as a baffle, agitates the exhaust gas and the injected reductant.
The DPF assembly 116 filters particulate from the exhaust gas passing through it. This particulate may accumulate within the DPF assembly 116 and may restrict the flow of exhaust gas through the DPF assembly 116 . The particulate may be removed from the DPF assembly 116 by a process called regeneration. A heater assembly 118 may be used to initiate the regeneration process.
SUMMARY
An engine control system comprises an engine speed control module and an idle limiting module. The engine speed control module selectively controls an engine based on an idle speed request. The idle limiting module selectively reduces the idle speed request by an amount that is based on a wheel slip value.
A method comprises selectively controlling an engine based on an idle speed request and selectively reducing the idle speed request by an amount that is based on a wheel slip value.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a functional block diagram of an engine and exhaust system for a vehicle according to the prior art;
FIG. 2 is a functional block diagram of an engine, an exhaust system, and a control system according to the principles of the present disclosure;
FIG. 3 is a functional block diagram of an exemplary implementation of the engine control module according to the principles of the present disclosure; and
FIG. 4 is a flowchart depicting exemplary operation of the engine control module according to the principles of the present disclosure.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
On surfaces having a low coefficient of friction, drive wheels of a vehicle may slip, even when the engine is idling and the accelerator pedal is not being pressed. Wheel slip is more likely to occur when idle speeds are high. For example only, diesel engines may naturally have a higher idle speed. Further, various operating modes, such as diesel particulate filter (DPF) regeneration, may increase idle speed.
In addition, torque converters that more suddenly transmit torque to the drivetrain may increase the likelihood of wheel slip. For example, diesel engines may use tight torque converters that allow less slip. Therefore, when the brake pedal is released, engine torque may be suddenly transmitted to the drivetrain, possibly causing wheel slip. According to the principles of the present disclosure, a control system may reduce the commanded idle speed in order to reduce the amount of wheel slip.
Referring now to FIG. 2 , a functional block diagram of an engine 102 , an exhaust system 106 , and a control system 202 is presented. While the engine 102 will be described herein as a diesel engine, the present disclosure also applies to other engine systems, such as spark ignition engine systems. The control system 202 includes a DPF control module 204 , an engine control module 206 , a transmission control module 208 , and a stability control module 210 . The DPF control module 204 may control the regeneration process in the DPF assembly 116 . The DPF control module 204 may receive a reading of an outlet temperature of the DPF assembly 116 . The DPF control module 204 communicates with the engine control module 206 .
The engine control module 206 outputs actuator values to the engine 102 to achieve a desired engine torque or engine speed. For example, the engine control module 206 may control the amount of turbocharger boost, the positions of intake and exhaust cam phasers, the amount of exhaust gas recirculation (EGR), the amount of airflow, and/or the amount of fuel injected into cylinders of the engine 102 . The engine control module 206 receives information about the currently-selected gear from the transmission control module 208 .
In addition, the engine control module 206 receives information about wheel slip from the stability control module 210 . For example only, the wheel slip information may be communicated over a vehicle network, such as a controller area network (CAN). The engine control module 206 may also receive an engine coolant temperature (ECT) signal from an ECT sensor 212 .
Referring now to FIG. 3 , a functional block diagram of an exemplary implementation of the engine control module 206 according to the principles of the present disclosure is presented. The engine control module 206 includes an idle control module 302 that generates a desired idle RPM.
A multiplexer 304 receives the desired idle RPM from the idle control module 302 and a limited idle RPM from a subtraction module 306 . The multiplexer 304 outputs either the idle RPM or the limited idle RPM to an actuator control module 310 . The actuator control module 310 generates actuator values for the engine 102 to achieve the selected idle RPM.
The selected output of the multiplexer 304 is determined by an enable signal from an enable module 320 . For example only, when the enable module 320 outputs an enable signal, the multiplexer 304 may select the limited idle RPM from the subtraction module 306 . Otherwise, the multiplexer 304 may select the idle RPM from the idle control module 302 .
The enable module 320 may generate the enable signal based on wheel slip and other conditions. For example, the enable module 320 may generate the enable signal when the amount of wheel slip is greater than a threshold. In various implementations, hysteresis may be used. For example, the enable module 320 may begin generating the enable signal when the wheel slip increases above a first threshold, and may stop generating the enable signal once the wheel slip falls below a second threshold that is less than the first threshold.
The enable module 320 may communicate with a timer 322 , which may limit the amount of time the enable signal will be generated. For example, once the wheel slip increases past the first threshold, the timer 322 may be reset, and the enable module 320 may stop producing the enable signal once the timer 322 reaches a predetermined value. The predetermined value may be based upon operating conditions and/or may be calibrated. For example, the predetermined period may be 15 seconds. Once the timer is exceeded, the enable module 320 may wait to generate the enable signal until the wheel slip falls below the second threshold.
The enable module 320 may limit generation of the enable signal to times when the selected gear is either first gear or reverse. In addition, the enable module 320 may limit generation of the enable signal to when the engine coolant temperature is above a threshold. The engine coolant temperature threshold may be established to avoid engine smoking at low engine temperatures. In various implementations, hysteresis may be used and two engine coolant temperature thresholds defined.
The enable module 320 may also limit generation of the enable signal to times when the DPF is not undergoing regeneration. However, if the DPF is undergoing regeneration and a temperature, such as the outlet temperature, of the DPF is high enough, the enable module 320 may still generate the enable signal. Hysteresis may also be used with the DPF outlet temperature. The enable module 320 may also limit generation of the enable signal to when the driver is applying little or no pressure to the accelerator pedal.
The enable signal may be sent to the PI module 308 . When the enable signal is first received, the PI module 308 may be initialized. For example, the PI module 308 may be initialized to the values in use when the enable signal was last generated. The PI module 308 may generate an offset that is subtracted from the idle RPM from the idle control module 302 by the subtraction module 306 .
The offset is based on a term that is proportional to an error value and a term that is based on an integration of the error value. The error value may be determined by subtracting acceptable wheel slip from the measured wheel slip. The acceptable wheel slip may be a calibratable value, such as two percent or three percent. The proportional term may be equal to a proportional constant times the error value, while the integral value may be equal to an integral over time of the error value multiplied by an integral constant. Upon initialization, the integral may be set to zero.
A maximum reduction and/or a minimum idle RPM may be defined. For example, the PI module 308 may be prevented from reducing the idle RPM by more than a predetermined value, such as 200 RPM. Alternatively, the subtraction module 306 may be prevented from producing a limited idle RPM less than a predetermined value, such as 600 RPM.
Referring now to FIG. 4 , a flowchart depicts exemplary operation of the engine control module 206 . Control begins in step 402 , where thresholds are initialized and a timer is reset. For example, a wheel slip threshold, an engine coolant temperature threshold, and a DPF outlet temperature threshold may be defined.
For each of these thresholds, a first and second value may be defined. Having two values allows for hysteresis. For example, idle RPM limiting may be enabled when the wheel slip increases past a first threshold and may be disabled when the wheel slip decreases below a second threshold, where the second threshold is less than the first threshold.
In step 402 , slip, ECT, and outlet threshold variables are set to first (upper) values. Control continues in step 404 , where limiting of the idle RPM is disabled. Control continues in step 406 , where control determines whether the measured wheel slip is greater than the slip threshold. If so, control transfers to step 408 ; otherwise, control transfers to step 410 . In step 410 , the slip threshold variable is set to the upper value. Control continues in step 412 , where the timer is reset and control returns to step 404 .
In step 408 , the slip threshold variable is set to a second (lower) value. Control continues in step 414 , where control determines whether the timer is greater than a predetermined threshold. If so, control transfers to step 415 ; otherwise, control transfers to step 416 . In step 415 , control disables limiting of the idle RPM and continues in step 417 . In step 417 , control determines whether the wheel slip is less than the slip threshold. If so, control transfers to step 410 ; otherwise, control remains in step 417 .
In step 416 , control determines whether pressure on the accelerator pedal is less than a predetermined threshold. If so, control transfers to step 418 ; otherwise, control returns to step 404 . In various implementations, control may transfer to step 418 when the driver is applying no pressure to the accelerator pedal.
In step 418 , control determines whether the engine coolant temperature is greater than the ECT threshold variable. If so, control transfers to step 419 ; otherwise, control transfers to step 420 . In step 420 , the ECT threshold variable is set to the upper value. Control then returns to step 404 .
In step 419 , the ECT threshold variable is set to a second (lower) value. Control continues in step 422 , where control determines whether the transmission is in either first gear or reverse. If so, control transfers to step 424 ; otherwise, control returns to step 404 . In step 424 , control determines whether DPF regeneration is off. If so, control transfers to step 426 ; otherwise, control transfers to step 428 . In step 428 , control determines whether the DPF outlet temperature is greater than the outlet threshold variable. If so, control transfers to step 430 ; otherwise, control transfers to step 432 .
In step 432 , the outlet threshold variable is set equal to the upper value and control returns to step 404 . In step 430 , the outlet threshold variable is set equal to a second (lower) value and control continues is step 426 . In step 426 , idle RPM limiting is enabled, and control returns to step 406 . The idle RPM may be limited based on the amount of measured wheel slip.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims. | An engine control system comprises an engine speed control module and an idle limiting module. The engine speed control module selectively controls an engine based on an idle speed request. The idle limiting module selectively reduces the idle speed request by an amount that is based on a wheel slip value. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority of European pat. app. no. 12179378.0 filed on Aug. 6, 2012, which is hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to a Hf-comprising material for use in the insulator of a RRAM device.
BACKGROUND ART
[0003] Resistive random-access memory (RRAM) is a non-volatile memory type under development. RRAM has recently gained much interest as a potential replacement for FLASH memory.
[0004] The basic idea is that a dielectric, which is normally insulating, can be made to conduct through a filament or conduction path formed after application of a sufficiently high voltage. The conduction path formation can arise from different mechanisms, including defects, metal migration, etc. Once the filament is formed, it may be reset (broken, resulting in high resistance) or set (re-formed, resulting in lower resistance) by an appropriately applied voltage.
[0005] At the basis of RRAM is a metal-insulator-metal (MIM) stack. HfO 2 has been of great interest as the insulator in the MIM stack. However, a better performance has been demonstrated by not only using HfO 2 as the insulator but by using a bi-layer of a stoichiometric HfO 2 layer and a non-stoichiometric O-deficient HfOx (x<2) layer. For HfO 2 , the commonly accepted mechanism of filament creation and destruction occurs by the diffusion of oxygen vacancies. Oxygen vacancies lead to defect states in the HfO 2 dielectric; if a large number of oxygen vacancies are present (locally), the HfO 2 dielectric becomes conductive. In such a bilayer stack, the non-stoichiometric O-deficient HfOx (x<2) layer can act as a sink for oxygen. So far, this O-deficient HfOx layer has always been deposited by PVD but for integration, it would be of great interest to deposit the layer by ALD, which is more manufacturing friendly and which is the method typically used for HfO 2 deposition. A general description of ALD is disclosed in [0004] to [0009] of US2005/0227003. So far, an ALD process for HfOx with x<2 has been elusive since no stable phase other than HfO 2 exists in the Hf-O phase diagram and the deposition of suboxides by ALD is generally difficult. There is therefore a need in the art for an alternative material which can be deposited by ALD.
SUMMARY OF THE DISCLOSURE
[0006] In certain aspects, the present disclosure provides an alternative to the PVD deposited O-deficient HfOx material, which can be deposited by ALD. This aspect can be achieved according to the disclosure with the materials as described herein.
[0007] In other aspects, the present disclosure provides a method for forming said material on a substrate. This aspect can be achieved according to the disclosure with the methods as described herein.
[0008] Herein is disclosed an ALD method leading to the fabrication of materials and in particular oxygen-deficient materials that can be used in combination with a HfO 2 layer to form the insulator of a MIM stack, advantageous for use in RRAM applications.
[0009] In a first aspect, the present disclosure relates to a method for the manufacture of a layer of material over a substrate, said method comprising
[0010] a) providing a substrate, and
[0011] b) depositing a layer of material on said substrate via ALD at a temperature of from 250 to 500° C., said depositing step comprising:
at least one HfX 4 pulse, and at least one trimethyl-aluminum (TMA) pulse,
[0014] wherein X is a halogen selected from Cl, Br, I and F and is preferably Cl.
[0015] In an embodiment, said HfX 4 pulse may be performed before said TMA pulse.
[0016] In an embodiment, the method may further comprise at least one oxidizer (Ox) pulse.
[0017] In an embodiment, said oxidizer pulse may be selected from H 2 O and O 3 pulses.
[0018] In an embodiment, said depositing step may comprise any one of the following sequence of pulses:
HfX 4 /TMA/optionally repeated one or more times, or HfX 4 /TMA/Ox/optionally repeated one or more times, or HfX 4 /Ox/TMA/optionally repeated one or more times.
[0022] In an embodiment, said depositing step may comprise any one of the following sequence of pulses or a combination thereof:
(HfX 4 /TMA/) n1 (HfX 4 /Ox/) m1 , or (HfX 4 /TMA/Ox/) n2 (HfX 4 /Ox/) m2 , or (HfX 4 /Ox/TMA/) n3 (HfX 4 )Ox/) m3 .
Wherein n1 is from 1 to 300, preferably from 1 to 50 and more preferably from 1 to 15,
Wherein n2 is from 1 to 500, preferably from 1 to 50 and more preferably from 1 to 15,
Wherein n3 is from 1 to 500, preferably from 1 to 50 and more preferably from 1 to 15,
Wherein m1, m2 and m3 are from 0 to 100, preferably from 0 to 30.
[0026] In embodiments where the deposition step comprises a combination of two or more of the above sequences, the sum of all n1, n2, n3, m1, m2, and m3 is preferably not more than 1000. As an example, for the following sequence {[(HfX 4 /TMA/) 10 (HfX 4 /Ox/) 5 ] 2 (HfX 4 /Ox/TMA/) 3 } 5 , said sum would amount to ((10+5)*2+3)*5=165 which is not more than 1000.
[0027] The notation A/B/ is shorthand for A pulse-purge-B pulse-purge.
[0028] Purging may involve a variety of techniques including, but not limited to, contacting the substrate and/or monolayer with an inert gas and/or lowering pressure to below the deposition pressure to reduce the concentration of a species contacting the substrate and/or chemisorbed species. Examples of inert gases include N 2 , Ar, He, Ne, Kr, Xe, etc. Purging may instead include contacting the substrate and/or monolayer with any substance that allows chemisorption by-products to desorb and reduces the concentration of a species preparatory to introducing another species. A suitable amount of purging can be determined experimentally as known to those skilled in the art. Purging time may be successively reduced to a purge time that yields an increase in film growth rate. The increase in film growth rate might be an indication of a change to a non-ALD process regime and may be used to establish a purge time limit.
[0029] Preferably, N 2 is used for purging.
[0030] In embodiments, the method may further comprise the step of providing a HfO 2 layer directly above or below said layer of material.
[0031] In embodiments, said HfO 2 layer may be provided by a sequence of p cycles of the sequence HfX 4 /Ox/.
[0032] In an embodiment, said depositing step may comprise any one of the following sequence of pulses or a combination thereof:
(HfX 4 /TMA/) n1 (HfX 4 /Ox/) m1 , or (HfX 4 /TMA/Ox/) n2 (HfX 4 /Ox/) m2 , or (HfX 4 /Ox/TMA/) n3 (HfX 4 /Ox/) m3 .
[0036] followed (or preceded) by the provision of a HfO 2 layer via the following sequence of pulses (HfX 4 /Ox/) p ,
[0037] wherein p is from 1 to 100 and preferably from 1 to 30.
[0038] In embodiments, X may be Cl.
[0039] In embodiments, said temperature may be from 300 to 400° C., preferably from 340 to 380° C., more preferably from 340 to 370° C. This is advantageous because higher temperature introduces a disadvantageous CVD component in the TMA ALD process and because lower temperature provide inexistent or negligible layer formation. In an embodiment, said temperature is the temperature of the substrate.
[0040] In an embodiment, the thickness of said layer of material may be from 0.3 to 100 nm.
[0041] In a second aspect, the present disclosure relates to a material comprising the elements Hf, Al and optionally C and/or O and/or X, wherein said material comprises at least the element C or O, wherein X is selected from Cl, Br, I and F (preferably Cl), wherein said elements makes up at least 90% of the at % (i.e., atomic percent) composition of the material as determined by XPS (and therefore ignoring the hydrogen content), wherein Hf represents from 17 to 40 at % of said elements (i.e. Hf, Al, C, O and X), Al represents from 5 to 23 at % of said elements, C represents from 0 to 45 at % of said elements, O represents from 0 to 62% of said elements, X represents from 0 to 10 at % of said elements, the sum of said elements amounting to 100 at %. In an embodiment, said elements Hf, Al and optionally C and/or O and/or X may make up at least 93%, preferably at least 96% and most preferably at least 99% of the at % composition of the material as determined by XPS.
[0042] These proportions in Hf, Al, C, O and X can be tuned by varying the proportion of sequences comprising an oxidative pulse. A higher proportion of sequences comprising an oxidative pulse leads to a lower Hf content, a lower C content, a higher Al content, a higher O content, and a lower X content.
[0043] It is worth noting that XPS analysis does not determine the hydrogen content of a sample. Of course, other elements than Hf, Al, C, O and X can be present in the composition as determined by XPS as long as they are not present in such an amount as to diminish the proportion represented by Hf, Al, C, O and X below 90%, preferably below 93%, more preferably below 96% and most preferably below 99% of the at % composition of the material as determined by XPS.
[0044] In embodiments, said material comprising the elements Hf, Al and optionally C and/or O and/or X, wherein said material comprises at least the element C or O, may further comprise from 0 to 20 at % of hydrogen as determined by Time-of-Flight Elastic Recoil detection analysis (TOF-ERDA). This value can be tuned by varying the proportion of sequences comprising an oxidative pulse. A higher proportion of sequences comprising an oxidative pulse leads to a lower hydrogen content.
[0045] In embodiments of the second aspect, the band gap of the material may be anywhere from 0 to about 6.5 eV. This value can be tuned by varying the proportion of sequences comprising an oxidative pulse. A higher proportion of sequences comprising an oxidative pulse leads to a larger band gap.
[0046] The material of the second aspect may be produced by the method of the first aspect.
[0047] In a first embodiment of the second aspect,
Hf may represent from 29 to 40 at% of said elements Hf, Al, C, O and X as measured by XPS, Al may represent from 5 to 15 at % of said elements Hf, Al, C, O and X as measured by XPS; C may represent from 31 to 45 at % of said elements Hf, Al, C, O and X as measured by XPS; O may represent from 0 to 14 at % of said elements Hf, Al, C, O and X as measured by XPS; X may represent from 0 to 10 at % of said elements Hf, Al, C, O and X as measured by XPS, the sum of said elements amounting to 100 at %,
[0054] In this first embodiment, said material may further comprise from 5 to 20 at % of hydrogen as determined by Time-of-Flight Elastic Recoil detection analysis (TOF-ERDA).
[0055] For instance, the first embodiment of the second aspect of the present disclosure may relate to a material comprising the elements Hf, C, Al, O and X, wherein said elements make up at least 90% (preferably at least 94, more preferably at least 96 and most preferably at least 99%) of the at % composition of the material as determined by XPS, wherein Hf represents from 34 to 40 at % of said elements (i.e. of Hf, C, Al, O and X), C represents from 36 to 45 at % and preferably 40 to 45 at % of said elements, Al represents from 9 to 14 at % of said elements, O represents from 0 to 9 at % and preferably from 0 to 6 at % of said elements and X represents 2 to 9 at % and preferably from 2 to 6 at % of said elements, the sum of said at % of said elements amounting to 100 at %, wherein X is a halogen selected from Cl, Br, I and F and is preferably Cl.
[0056] In the first embodiment of the second aspect, said material may be electrically conductive (i.e. behaving as a metal).
[0057] The material of the first embodiment of the second aspect may be produced by the method of the first aspect wherein no oxidizer pulse is used, i.e. wherein the sequence of pulse is (HfX 4 /TMA) n1 .
[0058] In a second embodiment of the second aspect,
Hf may represent from 17 to 23 at % of said elements Hf, Al, C, O and X as measured by XPS; Al may represent from 16 to 23 at % of said elements Hf, Al, C, O and X as measured by XPS; O may represent 57 to 62 at % of said elements Hf, Al, C, O and X as measured by XPS; C may represent from 0 to 3 at % of said elements Hf, Al, C, O and X as measured by XPS; X may represent from 0 to 1% of said elements Hf, Al, C, O and X as measured by XPS; the sum of said at % of said elements amounting to 100 at %.
[0065] The material of the second embodiment of the second aspect may be produced by the method of the first aspect wherein an oxidizer pulse is used in each sequence, e.g. wherein the sequence of pulse is (HfX 4 /TMA/Ox)n 2 or (HfX 4 /Ox/TMA)n 3 .
[0066] In embodiments, said material of the second embodiment of the second aspect may further comprise from 0 to 5 at % of hydrogen as determined by Time-of-Flight Elastic Recoil detection analysis (TOF-ERDA).
[0067] In a third aspect, the present disclosure relates to a material obtainable by the method according to any one embodiment of the first aspect.
[0068] In a fourth aspect, the present disclosure relates to a device comprising a metal-insulator-metal stack, said stack comprising:
A first metal layer, A layer of material according to any embodiment of the second or third aspect, A HfO 2 layer, and A second metal layer.
[0073] In a further aspect, the present disclosure relates to a memory device comprising a metal-insulator-metal stack of layers, wherein said insulator comprises a layer of material according to any one of the second, third or fourth aspect.
[0074] In an embodiment, said memory device may be a resistive RAM
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] The disclosure will be further elucidated by means of the following description and the appended figures.
[0076] FIG. 1 is a graph showing the mass gain of the substrate (a 300 mm wafer) after 100 full HfCl 4 /TMA cycles for a 4 s TMA pulse in function of the HfCl 4 pulse length according to an embodiment of the present disclosure.
[0077] FIG. 2 is a graph showing the mass gain of the substrate (a 300 mm wafer) after 100 full HfCl 4 /TMA cycles for a 3 s HfCl4 pulse in function of the TMA pulse length according to an embodiment of the present disclosure.
[0078] FIG. 3 is a graph showing the evolution of the sheet resistance after 100 full HfCl 4 /TMA cycles for a 3 sec TMA pulse length in function of the HfCl 4 pulse length according to an embodiment of the present disclosure.
[0079] FIG. 4 is a graph showing the evolution of the sheet resistance uniformity after 100 full HfCl 4 /TMA cycles for a 3 sec TMA pulse length in function of the HfCl 4 pulse length according to an embodiment of the present disclosure.
[0080] FIG. 5 shows the temperature dependency of the growth per cycle HfCl 4 (4 s)-purge-TMA (3 s)-purge according to an embodiment of the present disclosure.
[0081] FIG. 6 shows the temperature dependency of the film density according to an embodiment of the present disclosure wherein a pulse sequence HfCl 4 (4 s)-purge-TMA (3 s)-purge is repeated until saturation.
[0082] FIG. 7 shows the temperature dependency of the growth per cycle HfCl 4 (5 s)-purge-TMA (4 s)-purge-H 2 O (1 s) according to an embodiment of the present disclosure.
[0083] FIG. 8 shows the temperature dependency of the film density according to an embodiment of the present disclosure wherein a pulse sequence HfCl 4 (5 s)-purge-TMA (4 s)-purge-H 2 O (1 s) is followed.
[0084] FIG. 9 a shows the optical properties of a film produced according to an embodiment of the present disclosure wherein a pulse sequence HfCl 4 (5 s)-purge-TMA (4 s)-purge-H 2 O (1 s) is followed.
[0085] FIG. 9 b shows the optical properties of a film produced according to an embodiment of the present disclosure wherein a pulse sequence HfCl 4 (5 s)-purge-TMA (4 s)-purge-HfCl 4 (5 s)-purge-H 2 O (1 s) is followed.
[0086] FIG. 10 shows the composition as determined by XPS for a material according to the first embodiment of the second aspect of the present disclosure for a deposition temperature of 370° C.
[0087] FIG. 11 shows the composition as determined by XPS for a material according to the second embodiment of the second aspect of the present disclosure for a deposition temperature of 370° C.
[0088] FIG. 12 shows the composition as determined by XPS for a material according to the first embodiment of the second aspect of the present disclosure for a deposition temperature of 340° C.
[0089] FIG. 13 shows the composition as determined by XPS for a material according to the first embodiment of the second aspect of the present disclosure for a deposition temperature of 370° C.
[0090] FIG. 14 is a schematic representation of a device according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0091] The present disclosure will be described with respect to particular embodiments and with reference to certain drawings but the disclosure is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the disclosure.
[0092] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the disclosure can operate in other sequences than described or illustrated herein.
[0093] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the disclosure described herein can operate in other orientations than described or illustrated herein.
[0094] Furthermore, the various embodiments, although referred to as “preferred” are to be construed as exemplary manners in which the disclosure may be implemented rather than as limiting the scope of the disclosure.
[0095] The term “comprising”, used in the claims, should not be interpreted as being restricted to the elements or steps listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising A and B” should not be limited to devices consisting only of components A and B, rather with respect to the present disclosure, the only enumerated components of the device are A and B, and further the claim should be interpreted as including equivalents of those components.
EXAMPLES
[0096] All depositing steps have been performed in an ASM Pulsar® 3000 connected to a Polygon 8300.
[0097] The substrates were 300 mm Si (100) wafers having a 10 nm SiO2 top layer grown by rapid thermal oxidation.
[0098] The precursor HfCl 3 was purchased from ATMI and used as such.
Example 1
HfC Process
[0099] Adequate pulse length will vary in function of the used experimental set up, the optimal pulse length for the present experimental set up was therefore determined experimentally.
[0100] First, mass gain (mg) on the substrate at 370° C. was measured in function of HfCl 4 pulse length (ms) ( FIG. 1 ). It was observed that mass gain saturates at 11 mg for pulse lengths of 3 s or above.
[0101] Second, mass gain (mg) on the substrate at 370° C. was measured in function of TMA pulse length (ms) ( FIG. 2 ). It was observed that mass gain increases slowly with TMA pulse length. This was indicative of a small CVD component. Such CVD components get more dominant at higher temperature and are not favourable for ALD. This indicates that it is less advantageous to operate with a substrate above 370° C.
[0102] It is advantageous for the HFC material to be a bad dielectric or a metal. Sheet resistance and sheet resistance uniformity has therefore been measured for various HfCl 4 pulse lengths while keeping the TMA pulse at 3 seconds. The following pulse sequence was therefore performed on a substrate at 370° C.: HfCl 4 (2-5 s)/N 2 purge/TMA (3 s)/N 2 purge. A shorthand description of this same sequence is HfCl 4 (2-5 s)/TMA (3 s).
[0103] The corresponding graphs are shown in FIGS. 3 and 4 where RS stands for sheet resistance, RS U. stands for sheet resistance uniformity, and p.l. stands for pulse length. From these graphs it was observed that the lowest sheet resistance and the best uniformity was obtained for the following pulse sequence: HfCl 4 (4 s)/TMA (3 s). The resistivity of the obtained layer was about 20 mOhm.cm.
[0104] The sequence HfCl 4 (4 s)/TMA (3 s) was repeated until saturation at different temperatures in order to determine the temperature dependence of the growth per cycle (G. p. c.) (see FIG. 5 ).
[0105] The thickness was measured by x-ray reflectivity. From FIG. 5 , it is clear that the growth per cycle strongly increases above 300° C. and is best around 370° C. This indicates a usable temperature window of from 250° C. to 500° C. However, we know from FIG. 2 that it is less advantageous to operate with a substrate above 370° C., due to TMA decomposition (CVD component). No reaction and therefore no material layer deposition were observed below 250° C.
[0106] The temperature dependency of the material layer density was measured by x-ray reflectivity (see FIG. 6 ) on the same samples used for establishing FIG. 5 . It can be seen in FIG. 6 that a higher density is obtained at higher temperatures. The density remains however relatively low (4-5 g/cm 3 when compared to the bulk density (12.2 g/cm 3 ) of full crystalline HfC according to the literature.
[0107] The composition of the HfC material layer at various depths was determined by alternating etching (via Ar sputtering) and XPS analysis. This has been performed at a deposition temperature of 300 ( FIG. 13 ), 340 ( FIGS. 12 ), and 370° C. ( FIG. 10 ). Peaks characteristics of Hf, C, Al, Cl and O were found. At the deposition temperature of 370° C., the bulk concentration of C was from 41 to 44 at % as measured by XPS. The bulk concentration of Hf was from 35 to 38 at % as measured by XPS. The bulk concentration of Al was from 10 to 13 at % as measured by XPS. The bulk concentration of O was from 4 to 5 at % as measured by XPS. The bulk concentration of Cl was from 3 to 4 at % as measured by XPS. At the deposition temperature of 340° C., the bulk concentration of C was from 40 to 43 at % as measured by XPS. The bulk concentration of Hf was from 33 to 37 at % as measured by XPS. The bulk concentration of Al was from 9 to 12 at % as measured by XPS. The bulk concentration of O was from 6 to 9 at % as measured by XPS. The bulk concentration of Cl was from 5 to 7 at % as measured by XPS. At the deposition temperature of 300° C., the bulk concentration of C was from 32 to 38 at % as measured by XPS. The bulk concentration of Hf was from 30 to 37 at % as measured by XPS. The bulk concentration of Al was from 6 to 10 at % as measured by XPS. The bulk concentration of O was from 7 to 14 at % as measured by XPS. The bulk concentration of CI was from 3 to 9 at % as measured by XPS.
[0108] At each of these temperatures, the presence of the oxygen is believed to be due to the time the sample spent in the presence of air (30 min) before the XPS measurements. It can therefore in principle be reduced to zero.
Example 2
HfCO Process
[0109] The following pulse sequence was performed on a substrate at 370° C.: HfCl 4 (5 s)-N 2 purge-TMA (5 s)-N 2 purge-H 2 O (1 s)-N 2 purge.
[0110] The sequence HfCl 4 (5 s)/TMA (5 s)/H 2 O (1 s)/was repeated at different temperatures in order to determine the temperature dependence of the growth per cycle (G. p. c.) (see FIG. 7 ).
[0111] The thickness was measured by x-ray reflectivity. From FIG. 7 , it is clear that the growth per cycle is best around 370° C. This suggests a usable temperature window of from 250° C. to 500° C. However, we know from FIG. 2 that it is less advantageous to operate with a substrate above 370° C., due to TMA decomposition (CVD component). No reaction and therefore no material layer deposition were observed below 250° C.
[0112] The temperature dependency of the material layer density was measured by x-ray reflectivity (see FIG. 8 ). It can be seen in this figure that a the density decreases slowly between 300 and 370° C. The density remains however close to the expected bulk density. The expected bulk density is determined by an interpolation between bulk Al 2 O 3 and HfO 2 .
[0113] The composition of the HfCO material layer at various depths was determined by alternating etching (via Ar sputtering) and XPS analysis. Peaks characteristics of Hf, C, Al, and O were found. The bulk concentration of C was not determined because it was too close to the detection limit. The bulk concentration of Hf was from 18 to 23 at %. The bulk concentration of Al was from 16 to 21 at %. The bulk concentration of O was from 57 to 61 at %.
[0114] FIG. 9 a shows the optical properties ((absorption*photon energy) 2 vs. photon energy) of the material obtained via a pulse sequence HfCl 4 (5 s)-purge-TMA (4 s)-purge-H 2 O (1 s)-purge.
[0115] The band gap can be calculated from the optical properties by a linear interpolation of the square of the absorption coefficient to zero. These properties show that the obtained material is a dielectric material having a band gap of 6.3 eV.
[0116] FIG. 9 b shows the optical properties (absorption*photon energy) 2 vs. photon energy) of a material obtained via a pulse sequence HfCl 4 (5 s)-purge-TMA (4 s)-purge-HfCl 4 (5 s)-purge-H2O (1 s)-purge.
[0117] The band gap can be calculated from the optical properties by a linear interpolation of the square of the absorption coefficient to zero. These properties show that the obtained material is a dielectric material having a band gap similar of 6.1 eV.
[0118] FIG. 14 shows a device according to the fourth aspect of the present disclosure. It shows a substrate (1) on which a metal-insulator-metal stack is deposited, said stack comprising:
A first metal layer (2), A layer of material according to any embodiment of the second or third aspect (3), A HfO 2 layer (4), and A second metal layer (5). | The present disclosure relates generally to Hf-comprising materials for use in, for example, the insulator of a RRAM device, and to methods for making such materials. In one aspect, the disclosure provides a method for the manufacture of a layer of material over a substrate, said method including
a) providing a substrate, and b) depositing a layer of material on said substrate via ALD at a temperature of from 250 to 500° C., said depositing step comprising:
at least one HfX 4 pulse, and at least one trimethyl-aluminum (TMA) pulse,
wherein X is a halogen selected from Cl, Br, I and F and is preferably Cl. | 2 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application is a continuation application, and claims the benefit of U.S. patent application Ser. No. 11/963,912, filed Dec. 24, 2007, entitled “COMPOSITIONS AND METHODS FOR TREATING DISEASES ASSOCIATED WITH ANGIOGENESIS AND INFLAMMATION,” the disclosure of which is hereby incorporated herein by reference in its entirety, which is a continuation-in-part application, and claims benefit of U.S. patent application Ser. No. 11/208,288, filed Aug. 18, 2005, entitled “USE OF SOLUBLE CD26 AS INHIBITOR OF ANGIOGENESIS AND INFLAMMATION,” by Chiwen Chang, the disclosure of which is hereby incorporated herein by reference in its entirety. The application Ser. No. 11/208,288 claims the benefit, pursuant to 35 U.S.C. §119(e), of U.S. provisional patent application Ser. No. 60/605,013 filed Aug. 26, 2004, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to inhibitors of angiogenesis and inflammatory cytokines, and more specifically to pharmaceutical compositions for treating diseases or disorders associated with angiogenesis and inflammation.
BACKGROUND OF THE INVENTION
Angiogenesis is the formation of new blood vessels by sprouting from pre-existing ones. (Weinstate-Saslow, The FASEB Journal 8: 402-407, 1994; Folkman et al., Science 235: 442-447, 1987). The generation of new blood vessels involves a multistep process, which includes the migration of vascular endothelial cells into tissue, followed by the condensation of such endothelial cells into vessels. Angiogenesis may be induced by an angiogenic agent or be the result of a natural condition. The process is essential to a variety of normal body activities, such as embryo implantation; embryogenesis and development; and wound healing. The process involves a complex interplay of molecules that stimulate and molecules that inhibit the growth and migration of endothelial cells, the primary cells of the capillary blood vessels. (Folkman and Shing, J. Biol. Chem., 267 (16): 10931-34, 1989; Folkman and Klagsbrun, Science, 235, 442-47, 1987).
Several angiogenic agents have been identified. (Hanahan and Folkman, Cell, 86 (3): 353-364, 1996). For example, a number of growth factors have been identified which promote/activate endothelial cells to undergo angiogenesis. These include, by example and not by way of limitation; vascular endothelial growth factor (VEGF); transforming growth factor (TGFβ); acidic and basic fibroblast growth factor (aFGF and bFGF): and platelet derived growth factor (PDGF) (Ferrara and Davis-Smyth, Endocr Rev. 18 (1): 4-25, 1997). VEGF is believed to be a central mediator of angiogenesis. Antibodies directed against VEGF have been shown to suppress tumor growth in vivo and decrease the density of blood vessels in experimental tumors (Kim et al., Nature 362: 841-844, 1993), indicating that VEGF antagonists could have therapeutic applications as inhibitors of tumor-induced angiogenesis.
Normal angiogenic activity is low in healthy adults and limited to certain organs such as the uterus during pregnancy or intensely exercising skeletal muscle. However, its activity increases during injury and in diseases such as cancer, retinopathy, or arthritis, where it contributes to pathological changes. Therefore, angiogenesis can have both the beneficial effects such as facilitating wound healing, and detrimental effects by causing inflammatory diseases such as, for example, rheumatoid arthritis, macular degeneration, psoriasis, and diabetic retinopathy.
Furthermore, it has been shown that angiogenesis is essential for the growth of solid tumors and for tumor metastasis (Bouck et al., Adv Cancer Res.; 69: 135-74, 1996; Yancopoulos et al., Nature 407 (6801): 242-8, 2000). Tumor-induced angiogenesis is initiated by growth factors and cytokines that are released from the tumor or from inflammatory cell infiltrates (Brown et al., Am. J. Path. 143: 1255, 1993; Brown et al., Human Path. 26: 86, 1995; Leek et al., J. Leukocyte Biol. 56: 423, 1994; Hatva et al., Am. J. Pathol. 146: 368, 1995; and Plate et al., Nature 359: 845, 1992). Growth factors and cytokines which are expressed by tumor cells stimulate angiogenesis in a number of animal models including the chick chorioallantoic membrane model, the corneal pocket angiogenesis model, and models involving spontaneous and xenotransplanted tumor growth (Brooks et al., Cell 79: 1157, 1994; Brooks et al., Science 264: 569, 1994; Brooks et al., J. Clin. Invest. 96: 1815, 1995; and Friedlander et al., Science 27: 1500, 1995). Accordingly, tumor-associated angiogenesis is a potential target for therapies that inhibit tumor proliferation, invasion, and metastasis since angiogenesis has been implicated not only in the growth of tumors but also in their metastasis (Liotta et al., 1991, Cell 64: 327; Weinstat-Saslow et al., FASEB J 8: 401, 1994; Blood et al., Biochim. Biophys. Acta 1032: 89, 1990; Folkman, Semin. Cancer Biol. 3: 65, 1992; and Weidner et al., N. Engl. J. Med. 324: 1, 1991).
It has been well recognized that angiogenesis is involved in a variety of diseases or disorders and that such diseases or conditions can be treated by administration of angiogenesis inhibitors. Examples of pathological conditions involving angiogenesis include, but are not limited to, macular degeneration, ocular neovascular glaucoma, diabetic retinopathy, corneal graft rejection, vitamin A deficiency, Sjorgen's disease, acne rosacea, mycobacterium infections, bacterial and fungal ulcers, Herpes simplex infections, systemic lupus, rheumatoid arthritis, osteoarthritis, psoriasis, chronic inflammatory diseases (e.g., ulcerative colitis, Crohn's disease), hereditary diseases such as Osler-Weber Rendu disease and haemorrhagic teleangiectasia.
In an attempt to treat these diseases or conditions, many angiogenesis inhibitors have been discovered. Examples include endostatin (O'Reilly et al., 1997, Cell 88: 277), angiostatin (O'Reilly et al., 1994, Cell 79: 315), peptide CNGRCVSGCAGRC (SEQ ID NO: 3) (Arap et al., 1998, Science 279: 377), cyclic peptide RGDfV (Friedlander et al., 1995, Science 270: 1500), and monoclonal antibodies LM609 and P1F6 (Friedlander et al., 1995, Science 270: 1500). These drugs appear to target only on the angiogenesis aspect of the diseases without treating other additional, underlying mechanisms that are associated with or involved in the pathogenesis of the aforementioned diseases.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies, especially in connection with the method of identifying drug candidates for treating cancer, inflammatory diseases, and/or angiogenesis-associated diseases.
SUMMARY OF THE INVENTION
One aspect of the invention relates to a pharmaceutical composition that contains a therapeutically effective amount of sCD26 and/or a biologically active derivative thereof, and a pharmaceutically acceptable carrier. The pharmaceutical composition may further contain a therapeutically effective amount of sFlt-1 and/or a biologically active derivative thereof.
Another aspect of the invention relates to a method of treating a disease which is associated with and/or progresses by a biological activity of an inflammatory cytokine. The method includes the step of administering to a mammalian subject, who would benefit therefrom, a pharmaceutical composition containing a therapeutically effective amount of sCD26 as described above.
In one embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is administered to a mammalian subject having a disease associated with an increased interleukin activity, such as an increased IL-2 activity.
In another embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is administered to a mammalian subject having a disease such as a tumor and/or an inflammatory disease. The inflammatory disease includes rheumatoid arthritis, macular degeneration, psoriasis, and diabetic retinopathy.
Yet in another embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is administered to a mammalian subject having a disease such as a solid tumor, a tumor progression, tumor metastasis, and a latent tumor in a prevascular phase.
Another aspect of the invention relates to a method of treating a disease which is associated with and/or progresses by VEGF-associated angiogenesis and inflammatory cytokine-associated inflammation. The method includes the step of administering to a mammalian subject, who would benefit therefrom, a pharmaceutical composition containing therapeutically effective amounts of sCD26 and sFlt-1, and a pharmaceutically acceptable carrier.
In one embodiment of the invention, a pharmaceutical composition containing therapeutically effective amounts of sCD26 and sFlt-1 is administered to a mammalian subject having a disease such as a tumor and an inflammatory disease. Examples of an inflammatory disease include rheumatoid arthritis, macular degeneration, psoriasis, and diabetic retinopathy.
In another embodiment of the invention, a pharmaceutical composition containing therapeutically effective amounts of sCD26 and sFlt-1 is administered to a mammalian subject having a disease such as a solid tumor, tumor progression, tumor metastasis, and latent tumor in a prevascular phase.
Another aspect of the invention relates to a method of treating a disease in which the morbid state progresses by a biological activity of an inflammatory cytokine. The method includes the step of administering to a mammalian subject, who would benefit therefrom, a pharmaceutical composition containing a therapeutically effective amount of sCD26.
In one embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is administered to a mammalian subject having a disease such as a tumor and an inflammatory disease. The inflammatory disease includes rheumatoid arthritis, macular degeneration, psoriasis, and diabetic retinopathy. The tumor may be a solid tumor, tumor progression, tumor metastasis, and latent tumor in a prevascular phase.
In another embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is administered to a mammalian subject having a disease associated with an increased interleukin activity, such as an increased IL-2 activity.
Another aspect of the invention relates to a method of treating a disease in which the morbid state progresses by VEGF-associated angiogenesis and an inflammatory cytokine-associated inflammation. The method includes the step of administering to a mammalian subject, who would benefit therefrom, a pharmaceutical composition containing a therapeutically effective amount of sCD26 and sFlt-1, and a pharmaceutically acceptable carrier.
In one embodiment of the invention, a pharmaceutical composition containing therapeutically effective amounts of sCD26 and sFlt-1 is administered to a mammalian subject having a disease such as a tumor and an inflammatory disease. Examples of the inflammatory disease include rheumatoid arthritis, macular degeneration, psoriasis, and diabetic retinopathy.
In one embodiment of the invention, a pharmaceutical composition containing therapeutically effective amounts of sCD26 and sFlt-1 is administered to a mammalian subject having a disease such as a solid tumor, a tumor progression, tumor metastasis, and a latent tumor in a prevascular phase.
Yet another aspect of the invention relates to a method of inhibiting a biological activity of an inflammatory cytokine on a cell. The method includes the step of providing the cell with a pharmaceutical composition containing a therapeutically effective amount of sCD26, and a pharmaceutically acceptable carrier. The cytokine contains a motif XP, in which X is an amino acid and P is proline.
In one embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is provided to a cell for inhibiting a biological activity of IL-2 on the cell.
In another embodiment of the invention, a pharmaceutical composition containing a therapeutically effective amount of sCD26 is provided to a cell present in a mammalian subject, who would benefit from an inhibition of a biological activity of an inflammatory cytokine on the cell. The subject is suffering from a disease associated with and/or progresses by a biological activity of an inflammatory cytokine. Examples of such diseases include a tumor and an inflammatory disease. The inflammatory disease includes rheumatoid arthritis, macular degeneration, psoriasis, and diabetic retinopathy. The disease tumor includes a solid tumor, tumor progression, tumor metastasis, and latent tumor in a prevascular phase.
Further another aspect of the invention relates to a method of inhibiting VEGF-associated angiogenesis and an inflammatory cytokine-associated inflammation. The method includes the step of administering to a mammalian subject, who would benefit therefrom, a pharmaceutical composition containing therapeutically effective amounts of sCD26 and sFlt-1.
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. 1 illustrates the effect of trophoblast co-culture, or trophoblast culture supernatant, on the detection of VEGF produced by decidual leukocytes. Lane 1: leukocytes alone; Lane 2: leukocytes+trophoblasts; lane 3: leukocytes+JEG; lane 4: Leukocytes+trophoblasts supernatant.
FIG. 2A illustrates the result of the Western blot analysis of the supernatant of trophoblast culture as detected by an antibody specific against sFlt-1. Lane 1: supernatant of trophoblast culture; lane 2: 1 ng sFlt-1; lane 3: 10 ng sFlt-1.
FIG. 2B illustrates the result of the ELISA detections of sFlt-1 in the supernatant of the trophoblast cell culture. Lane 1: supernatant of trophoblast culture; lane 2: culture medium only.
FIG. 3A illustrates the detected concentrations of VEGF after incubation with various amounts of sFlt-1 in the VEGF ELISA assay. The amount of sFlt-1 used for incubation with VEGF was 10, 3, 1, 0.3, 0.1, and 0 ng in lanes 1˜6, respectively.
FIG. 3B illustrates VEGF-dependent proliferation of HUVECs was abolished by pre-treatment of VEGF with sFlt-1. HUVECs were cultured in basal medium alone (lane 1), medium containing VEGF (lane 2), medium containing sFlt-1 treated VEGF (lane 3), or medium containing anti-VEGF antibody-treated VEGF (control, lane 4).
FIG. 4 illustrates the steps for identifying the presence of placental sCD26 in the supernatant of trophoblast culture.
FIG. 5A is a schematic representation illustrating membrane bound CD26 and soluble CD26, and the recognition of the XP motif by soluble CD26.
FIG. 5B illustrates IL-2 contains the motif XP.
FIG. 6 illustrates IL-2 activity in stimulating CTLL-2 cell proliferation was abolished by pre-treatment with sCD26. The cell line CTLL-2 was cultured in a medium containing IL-2 (lane 1), without IL-2 (lane 2), or containing sCD26-pre-treated IL-2 (lane 3).
FIG. 7 illustrates neutralization of VEGF by sera from pregnant women in ELISA.
FIG. 8A illustrates the average amount of sFlt-1 from serum samples of 5 subjects in each test group: pregnant women (lane 1), non-pregnant women (lane 2) and men (lane 3).
FIG. 8B illustrates the level of sFlt-1 in the serum from a pregnant woman at 20 weeks of pregnancy (lane 1), 30 weeks of pregnancy (lane 2) and 10 weeks after giving birth (lane 3).
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, “VEGFR1,” “sVEGFR1,” or “sFlt-1” refers to protein, peptide, or polypeptide receptor, an alternatively spliced form, or a biologically active derivative thereof, having vascular endothelial growth factor receptor type 1 (Flt) activity, for example, having the ability to bind a vascular endothelial growth factor. The biological activity of a sFlt-1 polypeptide may be assayed using any standard method, for example, by assaying sFlt-1 binding to VEGF. Soluble Flt-1 lacks the transmembrane domain and the cytoplasmic tyrosine kinase domain of the Flt-1 receptor. Soluble Flt-1 can bind to VEGF and P1GF with high affinity, but it cannot induce proliferation or angiogenesis and is therefore functionally different from the Flt-1 and KDR receptors. As used herein, sFlt-1 includes any sFlt-1 family member or isoform. Soluble Flt-1 can also mean degradation products or fragments that result from enzymatic cleavage of the Flt-1 receptor and that maintain sFlt-1 biological activity. Soluble Flt-1 can be used to antagonize VEGF function.
As used herein, the term “biologically active derivative of sFlt-1” refers to a biological active protein or peptide fragment that comprises an amino acid sequence modified from the human sFlt-1.
As used herein, the term “human sFlt-1” refers to a biological active protein or peptide fragment that comprises an amino acid sequence of sFlt-1 of a human origin.
As used herein, the term “soluble CD26,” or “sCD26” refers to a protein, peptide, an alternatively spliced form, or a biologically active derivative thereof, that has DPPIV enzymatic activity. A soluble form of CD26 is capable of cleaving N-terminal dipeptides from polypeptides with either proline or alanine residues in the penultimate position. The enzymatic activity of sCD26 is usually assayed by digestion of a commercially available chemically synthesized substrate Gly-Pro-p-nitroanilide (Sigma, CAT NO G2901).
As used herein, the term “biologically active derivative of sCD26” refers to a biological active protein or peptide fragment that comprises an amino acid sequence modified from the human sCD26.
As used herein, the term “human sCD26” refers to a biological active protein or peptide fragment that comprises an amino acid sequence of sCD26 of a human origin.
As used herein, the term “neutralization of VEGF” refers to the blocking of VEGF from binding to its receptor and result in a loss of VEGF activity such as VEGF-dependent cell proliferation.
As used herein, the term “a mammalian subject” includes a mammalian animal and a human being.
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 light 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.
Material and Methods
Tissue samples were obtained from elective termination of first trimester pregnancies from Addenbrookes Hospital, Cambridge, UK.
Isolation of Decidual Leukocytes
Preparation of maternal decidual leukocytes was carried out as described by King et al. (Hum. Immunol., 24 (3); 195-205 (1989)) with minor modifications. Samples of decidual tissues were sorted by macroscopical examination and washed in cold RPMI 1640 (Invitrogen, USA, Catalog No. 21875-034) for 10-20 minutes before being minced into small pieces with a surgical blade. Approximately 10 grams of minced tissue were digested in 25 ml of RPMI 1640 containing 10% fetal calf serum (FCS) (Harlan Sera-Lab, UK, Catalog No. S-0001A), 2 ml of Collagenase (10 μg/ml, Sigma, U.S., Catalog No. C5138), and 0.5 ml DNase I (3 μg/ml, Sigma D5025) at 37° C. on a roller incubator for 30 minutes. The sample tube was centrifuged briefly to pellet pieces of tissue and the cell-containing supernatant was filtered through a 100 μm filter (Becton Dickinson, USA, Catalog No. 352360). The flow-through was centrifuged at 650×g for 5 minutes to pellet cells. The supernatant was added back to the tissue which had been passed through a 10 ml pipette a few times to further break up the tissue. The mixture was incubated for another 10 minutes at 37° C. The sample tube was then centrifuged briefly to pellet tissues and supernatant was filtered through 100 μm filter. Filtered supernatant was centrifuged at 650×g for 5 minutes to pellet the cells. The cell pellet was resuspended in 15 ml of PBS (Current Protocols in Molecular Biology, Wiley Press, page 4.2.3, 1996) containing 2% FCS and 0.1% azide before being overlaid onto 15 ml of LYMPHOPREP™, a ready-made, sterile and endotoxin-tested solution suitable for the purification of human mononuclear cells (Axis-Shield Diagnostics, Norway, Catalog No. 1114545). The tube was centrifuged at 710×g for 20 minutes without brake and the cells at the interface were collected and washed once in RPMI 1640 (10% FCS). Decidual leukocytes prepared in this method consisted of approximately 60% NK cells (CD56 + CD16 − ), 15-20% macrophages (CD14 + ), 10% T cells and other stromal cells.
Isolation of Fetal Trophoblast Cells
Fragments of placental tissue were identified macroscopically and washed in RPMI 1640 medium for a few minutes. The tissue was scraped with a scalpel blade and then digested in 20 ml of prewarmed (37° C.) 0.25% trypsin (Becton Dickinson, USA, Catalog No. 215240) solution containing 0.02% EDTA for 8-9 minutes on a hotplate with stirring. Twenty milliliters of HAMS F12 (LIFE Technologies, USA, Catalog No. 074-90587) (20% NCS (Invitrogen, USA, Catalog No. 16010-167)) were added to the solution to stop trypsinization. The solution was then filtered through gauze and centrifuged in 50 ml tubes at 450×g to pellet the cells. The cell pellet was resuspended in 10 ml of HAMS F12 and the cell solution was overlaid onto 10 ml of LYMPHOPREP™, a ready-made, sterile and endotoxin tested solution suitable for the purification of human mononuclear cells (Axis-Shield Diagnostics, Norway, Catalog No. 1114545), and centrifuged at 710×g for 20 minutes. Cells at the interface were recovered and washed once with 10 ml of HAMS medium. To deplete placental macrophages, the cell pellet was resuspended in 3 ml of HAMS and seeded onto a petri dish and incubated for 20 minutes at 37° C. Fetal trophoblast cells in the supernatant were recovered by centrifugation at 600×g for 5 minutes.
Concentration of Fetal Trophoblast Cell Culture Supernatant
Fetal trophoblast cells isolated as described above were cultured in RPMI-1640 medium plus 10% fetal calf serum (FCS) at 1×10 6 cells/nil at 37° C. overnight. The supernatant was collected and centrifuged at 1,000×g for 5 minutes to pellet the cell debris before being loaded onto a centrifugal filter device CENTRICON® (Millipore, YM-10) and centrifuged at 2,000 RPM for around 1 hour. The volume was usually reduced to 1:10 of the original volume to obtain a 10×-concentrated supernatant.
EXAMPLE 1
Placental Trophoblast Co-Culture Inhibited the Detection of VEGF Secreted by Decidual Leukocytes
Decidual Leukocytes Co-Cultured with Placental Trophoblasts
Decidual leukocytes and placental trophoblasts were isolated as described above. A trophoblast tumor cell line JEG cultured in RPMI-1640 medium (10% FCS) was used as a negative control. One hundred μl of leukocytes (3×10 6 cells/ml) were seeded onto each well of a 96-well U-bottom plate with or without 100 μl of the isolated trophoblasts, or with negative control cells JEG (1×10 6 cells/ml). After overnight incubation, the culture supernatants were harvested and stored at −70° C. for later ELISA assay. One hundred μl of each stored supernatant was thawed and used in a VEGF ELISA assay (R&D, USA, Catalog No. DY293) according to the manufacturer's instruction manual.
FIG. 1 shows the results of the assay: Lane 1 shows the concentration of VEGF produced by decidual leukocytes and detected in the culture supernatant by the VEGF ELISA assay. Lane 2 shows the disappearance of the VEGF in the culture supernatant when the decidual leukocytes were co-cultured with isolated trophoblasts un the same dish. As a negative control, lane 3 illustrates the presence of VEGF when decidual leukocytes were co-cultured with the cell line JEG. The data indicates that the inhibition of VEGF detection was not an artifact induced by co-culture per se because JEG co-culture did not produce the same effect. Instead, it was specifically due to the co-culture with the isolated trophoblasts. This effect of trophoblasts on the detection of VEGF could also be repeated by adding the culture supernatant from trophoblast-only cell culture. The assay results indicated that it was possible that some kind of soluble factor(s) was secreted into the culture supernatant by trophoblasts and caused abolishment of VEGF detection in the ELISA assay.
EXAMPLE 2
Detection of Placental Soluble Fins-Like Tyrosine Kinase 1 (sFlt1) in Supernatant of Trophoblast Cell Culture
It has been know that sFlt-1, which was initially purified from human umbilical endothelial cells, is produced by trophoblast cells in vivo. In one example, specific metalloproteinases released from the placenta may cleave the extracellular domain of Flt-1 receptor to release the N-terminal portion of Flt-1 into circulation. A soluble form of Flt-1 (i.e., sFlt-1) can be detected in peripheral blood and is a ligand with a high affinity to VEGF. To investigate whether sFlt-1 was a factor secreted into the culture supernatant by trophoblast co-culture and caused abolishment of VEGF detection in FIG. 1 , the following experiments were performed.
Western Blot Analysis
Twenty microliters of trophoblast supernatant or pure sFlt-1 (R&D Systems CAT NO 321-FL) were mixed with 4 μl of 6×SDS gel loading dye, and boiled for 5 minutes before being loaded onto a 10% SDS polyacrylamide gel (Bio-Rad CAT NO 161-1101). The gel was run at 100 volts for 1.5 hours and blotted onto a PVDF membrane at 100 volts for 1 hour. The blot was incubated in a 10% milk/TBST buffer containing 0.1 μg/ml polyclonal goat anti-sFlt-1 antibody (R&D Systems CAT NO AF321) for 2 hours at room temperature. After washing 3 times in the TBST buffer, a secondary antibody rabbit anti-goat HRP-conjugated antibody (DakoCytomation CAT NO P0449) was used in the blot at dilution 1:2000 in 10% milk/TBST for 1 hour. After washing 3 times, the band was detected using an ECL kit (GE Healthcare CAT NO RPN2106) according to the manufacturer's instruction manual.
FIG. 2A is a Western blot that shows using an anti-sFlt-1 antibody, a protein band of around 110 Kd was detected in the trophoblast supernatant (Lane 1). The same molecular weight band was detected in the positive control as well (lanes 2 and 3, loaded with different amount of pure sFlt-1 protein, respectively). The result indicates soluble Flt-1 was present in the trophoblast supernatant.
Soluble Flt-1 ELISA Assay
One hundred microliters of the supernatant from the trophoblast cell culture were used for assay of soluble Flt-1 present in the trophoblast culture by using sFlt-1 ELISA kit (R&D Systems, CAT NO DVR100B) according to the manufacturer's instruction manual. FIG. 2 B shows the result of the ELISA detections of sFlt-1 in the supernatant of the trophoblast cell culture. Lane 1: supernatant of trophoblast culture; lane 2: culture medium only. The result indicated that a large amount of soluble Flt-1 was detected in the supernatant of trophoblast culture by ELISA.
EXAMPLE 3
Neutralization of VEGF by sFlt-1
VEGF ELISA Assay
Pure sFlt-1 (1 μg/ml) was serially diluted (dilution 1:3) in PBS buffer. Ten microliteres of each diluted sFlt-1 were mixed with 90 μl of VEGF (1.1 ng/ml; R&D Systems, MN, USA) and incubated for 1 hour at 37° C. After the incubation, the 100 μl mixture was used for VEGF ELISA. FIG. 3A shows the detected concentrations of VEGF after incubation with various amounts of sFlt-1 in the VEGF ELISA assay. The amount of sFlt-1 used for incubation with VEGF was 10, 3, 1, 0.3, 0.1, and 0 ng in lanes 1-6, respectively. Since soluble Flt-1 was serially diluted from 10 ng down to 0.1 ng before incubation with 1 ng of VEGF, the result indicates that sFlt-1, in a sufficient concentration, binds to all the VEGF and prevents VEGF from being detected in ELISA assay. The neutralization of VEGF by sFlt-1 was dose-dependent. When 3 ng of sFlt-1 was used, almost all of 1 ng of VEGF in the solution was neutralized (lane 2).
EXAMPLE 4
Soluble Flt-1 Abolished VEGF-Dependent HUVECs Proliferation
Isolation of Human Umbilical Vein Endothelial Cells (HUVECs)
HUVECs were isolated as described by Jaffe, E. A. et al. (J. Clin. Invest. 52 (11): 2745-2756, 1973) with minor modifications. Briefly, human umbilical cord was collected into 150 ml of PBS buffer containing 1 μg/ml fungizone (Gibco, USA, Cat No. 15295-017). The cord was washed with sterile PBS and the damaged ends were cut off with a surgical blade. The vein was located and cannulated with a sterile Kwill filling tube (Avon Medicals, UK, Cat No. E910) at both ends of the cord. The umbilical cord was tied up at the cannulated region with a sterile thread. The cord blood was then flushed out with 100 ml PBS, and 20 ml of PBS was gently flushed back and forth between two 20 ml syringes (Becton Dickinson, USA, Catalog No. 300613). After flushing the cord thoroughly, the excess PBS was removed. Ten milliliters of collagenase solution (10 μg/ml) were added at (Sigma, USA, Catalog No. C-9891) and the ends of cannulas were plugged. The cord was then placed in a pre-warmed beaker containing PBS for 10 minutes. The collagenase solution in the cord was gently flushed back and forth between two syringes and the flow-through was collected in a 50 ml centrifuge tube. The cord was then washed with 10 ml of Medium-199 medium (Sigma, USA, Catalog No. M-7528) into the same tube. The tube was centrifuged at 200×g for 5 minutes to collect the HUVECs. The cells were re-suspended in 10 ml of endothelial cell growth medium (PromoCell, USA, Catalog No. C22010) and cultured in an incubator at 37° C. for further experiments.
Effect of sFlt-1 on VEGF-Dependent HUVEC Proliferation
HUVECs isolated as described above were re-suspended in Medium-199 (Sigma, USA, Catalog No. M-7528) at 2×10 5 cells/ml, and plated 50 μl per well in a 96-well flat bottom plate (Becton Dickinson, USA, Catalog No. 353072). VEGF was diluted in Medium-199 medium to give 1 μg/ml. Neutralization of VEGF by sFlt-1 was accomplished by incubating VEGF (1 μg/ml) with equal volume of sFlt-1 (5 μg/ml; R&D Systems, MN, USA) at 37° C. for one hour. After the neutralization, the VEGF in the solution was diluted to 20 ng/ml with an assay medium (M-199 plus 10% FCS and 10 mM HEPES). The sFlt-1 pre-treated and diluted VEGF was added into the HUVEC culture at 50 μl per well. As control, VEGF (1 μg/ml) was incubated with anti-VEGF antibody (R&D MAB293, 10 μg/ml) at room temperature for one hour. After addition of control VEGF or sFlt-1 pre-treated VEGF into the HUVECs culture, the plate was incubated at 37° C. for three days before measuring cell proliferation by using a tetrazolium based assay kit (Promega CAT No G3580).
The proliferation of HUVECs reflects a response to the stimulation by VEGF. Without the supply of VEGF, HUVEC culture will stop growing and gradually die off. Since HUVEC proliferation in response to VEGF stimulation is essential in angiogenesis in vivo, a test compound or composition that results in an inhibition of VEGF activity in the present assay may be considered to have anti-angiogenesis properties.
As shown in FIG. 3B , HUVECs cultured in a medium containing VEGF (lane 2) exhibited an increase in cell growth as compared to those cultured in a basic medium without VEGF (lane 1). The result indicated that VEGF present in the culture medium stimulated proliferation of HUVECs. HUVECs cultured in a medium containing sFlt-1 pre-treated VEGF (i.e., neutralized VEGF), however, did not exhibit an increase in cell growth. This indicated VEGF had lost activity in stimulating HUVECs proliferation due to neutralization by pre-treatment with sFlt-1 before being added into the HUVECs culture. Since HUVEC proliferation in response to VEGF stimulation is essential in angiogenesis, sFlt-1, by inhibiting or abolishing VEGF activity in stimulating HUVECs proliferation, has proved to possess anti-angiogenesis property.
EXAMPLE 5
Placental sCD26 Identified in the Supernatant of Trophoblast Culture
FIG. 4 illustrates the steps of generating monoclonal antibody CH15 and using the generated CH15 in the immunoprecipitation experiments.
Generation of Hybridoma Cell lines Producing Monoclonal Antibodies Against Proteins in the Supernatant from Trophoblasts Culture
Ten times concentrated supernatant from trophoblast culture prepared as described above was used to immunize a Balb/c mouse. The spleen cells from the immunized mouse were fused with SP2/0 cells according to the manufacturer's procedure for generation of hybridoma (StemCell Technologies, CLONACELL™-HY, Catalog No. 03800). A hybridoma cell clone producing IgG antibody CH15 was identified.
Purification of Monoclonal Antibody CH15 from Hybridoma Supernatant
The monoclonal antibody CH15 in the hybridoma cells culture supernatant was purified by protein-A column. Briefly, 0.5 g protein-A sepharose powder (Sigma, USA, Catalog No. P3391) was hydrated in 1 ml PBS buffer (pH 7.4) and loaded into a plastic column (Bio-Rad, USA, Catalog No. 732-1010). The column was washed with 10 ml PBS buffer (pH 8). The hybridoma supernatant was then passed through the protein-A column slowly allowing the antibody to bind to the protein-A column. Afterwards, the protein-A column was washed a few times with the buffer solution and antibody eluted from the column with 100 mM glycine (pH 3) (Antibodies, Harlow, E. and Lane, D., Cold Springs Harbor Lab Press, 1988, p. 310).
Immobilization of CH15 onto Agarose Gel
The purified monoclonal antibody CH 15 (200 μg) as aforementioned was immobilized onto an agarose gel for immunoprecipitation according the manufacturer's instruction manual (SEIZE™ primary immunoprecipitation kit, Pierce Catalog No. 45335). FIG. 4 illustrates Monoclonal antibody CH15 (Mab CH15, next to the column) was immobilized onto the column.
Immunoprecipitation of CH15-Specific Protein in Trophoblast Culture Supernatant
As shown in FIG. 4 , ten times concentrated trophoblast supernatant (abbreviated as Troph sup in FIG. 4 ) was loaded into the column and incubated with the CH15 antibody-conjugated agarose gel described above for overnight at 4° C. to allow the CH15 antibody to bind the CH15-specific factor in the supernatant. The agarose gel was then washed a few times with a buffer solution and the proteins were eluted from the antibody-conjugated agarose gel with an elution buffer.
Visualization of CH15-Immunoprecipitated Protein on a Polyacrylamide Gel
The aforementioned, eluted sample (20 μl) was mixed with a gel loading dye (5 μl) and boiled for 5 minutes. The sample was then loaded into a 10% SDS polyacrylamide (SDS-PAGE) gel and electrophoresis was run at 100 volts for 1.5 hours in Tris-Glycine buffer (Current Protocols in Molecular Biology, Wiley Press, page A.2.5, 1996) with 2 mM mercaptoacetic acid (Sigma, USA, Catalog No. T-6750). After the gel electrophoresis, the proteins in the gel were blotted to a PVDF membrane (Bio-Rad, USA, Catalog No. 162-0185) in CAPS buffer (19 mM CAPS (Sigma, USA, Catalog No. C-4142), 5 mM DTT (Sigma, USA, Cat No. D9163), 10% Methanol, (pH 11) at 50 volts for one hour. After blotting, the membrane was stained with Coomassie Blue R-250 (Bio-Rad, USA, Catalog No. 161-0435) or stained by silver staining (Bio-Rad, USA, Catalog No. 161-0449) according to the manufacturer's instructions to visualize the proteins immunoprecipitated by CH15.
FIG. 4 illustrates the protein bands visualized by silver staining. Lanes 1˜3 are eluted fractions from the antibody-conjugated agarose gel. Lanes 4˜6 are eluted fractions from a negative control. After staining, a protein band of approximately 110 kDa (lanes 1-3, located slightly above the 97 Kd marker band) was cut out and sequenced. The results of amino acid sequencing of the ˜110 Kd immunoprecipitated band (NKGTDDATADSR . . . ) (SEQ ID NO: 1) matched the sequence of sCD26.
Identification of Placental sCD26 Present in Trophoblast Culture Supernatant
The amino acid sequencing data indicates that the immunoprecipitated protein was a soluble form of placental CD26. The results indicated that placental sCD26 was present in the supernatant of cultured trophoblast cells and immunoprecipitated by CH15 on the SDS PAGE gel.
The above disclosures illustrate how to obtain and identify one form of sCD26 from the human placenta trophoblast cells. Different forms of soluble CD26 have also been reported. For example, sCD26 that is found in the normal human blood has an amino acid sequence that is ten residues shorter than its placenta counterpart. Soluble CD26 in a recombinant protein form may be obtained from commercial sources such as R&D Systems (Minneapolis, U.S.A.).
Human blood CD26 is a 240 kDa homodimeric type II membrane glycoprotein comprised of two 120 kDa subunits. (Mentlein, R., International Review of Cytology, 235: 165-213, 2004). It is also known as a dipeptidyl peptidase IV (DPPIV). As a membrane-bound glycoprotein, it possess various functional properties including modulating the activity of various biologically important peptides (Dang et al., Histol. Histopathol., 17: 1213-1226, 2002). CD26 has been found expressed on a variety of cell types, particularly melanocytes, epithelial cells, endothelial cells and lymphocytes.
Human blood sCD26, which lacks the first 38 residues as compared to its counterpart membrane bound CD26, has been postulated as a cleaved product from the membrane CD26. (Iwaki-Egawa et al., J. Biochem. (Tokyo) 124; 428-433 (1998)).
Human placental sCD26, a cleaved product from the placental membrane CD26 as well, lacks the first 28 residues as compared to the placenta membrane bound CD26. Therefore, a human placental sCD26 has an additional 10 amino acid residues at its N-terminus as compared to human blood sCD26. FIG. 5A illustrates a placental membrane CD26 as a homodimeric, membrane-bound protein, which may be cleaved (indicated by two arrows) and result in a homodimeric, placental sCD26.
A survey of literature led to the finding that sCD26 has been reported to cleave a NH 2 -terminal dipeptide in a polypeptide having either L-proline or L-alanine at the penultimate position (Fleischer, Immunol Today 15; 180-184 (1994)). Many biologically active polypeptides have this sequence. For example, a proline residue is present at the penultimate position in many cytokines, such as IL-1β, IL-2, IL-6, and G-CSF. (Ansorge et al., Biomed Biochim Acta 50; 799-807 (1991)). FIG. 5A illustrates sCD26 cleaves an amino-terminal dipeptide in a polypeptide that has a L-proline at the penultimate position.
Studies have shown that sCD26 has many physiological roles, including a role in immune regulation as a structure capable of transmitting T cell activation signals and a role as a regulator of biological processes through its cleavage of biological factors. Activation of a T cell is a complex process involving various secreted interleukins, which acts as local chemical mediators. Activation is thought to begin when the T cell, by unknown means, is stimulated by the antigen-presenting cell to secrete one or more interleukins. Interleukin 2 (IL-2) is a protein produced by T-lymphocytes that have been activated by an antigen. IL-2 stimulates other lymphocytes to activate and differentiate. IL-2 is a central cytokine required for the activation of T, B and natural-killer (NK) cells. (Tenbrock et al., Int Rev Immunol., 23 (3-4); 333-345, 2004).
Human IL-2 is a protein of 133 amino acids (15.4 kDa) with a slightly basic pI that does not display sequence homology to any other factors. Murine and human IL-2 display a homology of approximately 65%. IL-2 is synthesized as a precursor protein of 153 amino acids with the first 20 amino-terminal amino acids functioning as a hydrophobic secretory signal sequence. The protein contains a single disulfide bond at positions Cys58 and Cys105, which is essential for biological activity.
It is well known in the art that IL-2 is a pro-inflammation cytokine in the human immune system. There are numerous examples of the pathological role IL-2 plays in the inflammatory and immune diseases. For example, the level of IL-2 production is altered in patients suffering from the multiple sclerosis and reduced in patients suffering from systemic lupus erythematosus. (Dejica D., Rorum Arch Microbiol Immunol., 60 (3): 183-201, 2001; Herndon et al., Clin. Immunol., 103 (2), 145-53, 2002; Tenbrock et al., Int Rev Immunol., 23 (3-4): 333-45, 2004). Development of a molecule that is able to alter the IL-2 activity would be useful in the treatment of autoimmune and inflammatory disorders. Since many cytokines contains a proline residue at the penultimate position, the effects of placental sCD26 on IL-2 were further investigated and experiments were illustrated as follows.
EXAMPLE 6
sCD26 Abolished IL-2 Activity in Stimulating CTLL-2 Cell Proliferation
Purification of Placenta Soluble CD26
For every gram of PBS-washed placenta tissue, four milliliters of RPMI-1640 (w/o FCS) were added and the tissue was incubated at 37° C. incubator for 3-4 days before supernatant was harvested. Supernatant was centrifuged at 700×g for 5 minutes to remove debris. The soluble CD26 in the solution was purified through ADA (Sigma CAT NO A6648) column according to the published method (de Meester et al J Immunol Methods. 1996 Jan. 16; 189 (1): 99-105). The purified sCD26 was eluted from the column with 30 ml of 2 mM Tris (pH8) and concentrated down to 3 ml using Centricon Plus-70 device (Amicon CAT NO UFC 701008) and aliquots stored at 4° C. for later use. The purified and concentrated sCD26 was used later for the following experiment.
Production of Human IL-2 with Native N-Terminus
Most of commercially available IL-2 is produced from bacteria and thus the N-terminus of the protein is modified with an extra amino acid Methionine (M) on it. The methionin-N-terminal IL-2 is not an ideal substrate for studying the function of soluble CD26 because sCD26 recognizes only the exact N-terminal amino acid sequences of a protein. We therefore cloned the human IL-2 gene into a plasmid vector with a Flag-tag at the C-terminus for later purification purposes, and transfected the recombinant vector into a Eucaryotic cell line BaF3. A stable clone that produced IL-2 was identified and grown to a large volume. The IL-2 was produced and concentrated in the supernatant, which was then used in the following experiment.
CTLL-2 Cell Proliferation Assay
The CTLL-2 (ATCC, TIB214) cell line constitutively expresses IL-2 receptors and depends entirely on the presence of exogenous IL-2 for cell growth. The CTLL-2 cells were used to assay the effect of sCD26 on the activity of IL-2 in stimulating CTLL-2 cell growth. The activity of IL-2 in stimulating CTLL-2 cell growth was assayed by using a cell proliferation kit for measuring the absorbance at OD 490 . Before the experiment, CTLL-2 cells (0.1×10 6 cells/ml) were washed twice with RPMI-1640 and plated 50 μl per well in 96-well plates. The IL-2, which was produced as described above, was pre-treated with the sCD26, which was purified from placenta cell culture supernatant as mentioned above, by mixing 1 μl of concentrated IL-2 supernatant with 20 μl of purified, concentrated sCD26 for 1 hour at 37° C. After treatment, IL-2 was adjusted to 50 μl and mixed with CTLL-2 cells, 0.1×10 6 /ml at 50 μl per well. The cell culture was incubated at 37° C. for 3 days before measuring cell proliferation at OD 490 (Promega, CAT No G3580).
FIG. 5A illustrates soluble CD26 can recognize a polypeptide that contains a motif XP and cleave the peptide bond thereafter. FIG. 5B illustrates IL-2 contains an amino acid sequence APTSSSTKK . . . (SEQ ID NO: 2) with the motif AP (alanine-proline) that can be recognized by sCD26.
FIG. 6 illustrates the growth of cell line CTLL-2 was dependent on IL-2 in the growth medium. Without the supply of exogenous IL-2, the CTLL-2 cell line stopped growth and died off quickly (lane 2) as compared to that in the medium containing IL-2 (lane 1). Pre-treatment of IL-2 with aforementioned purified and concentrated sCD26 rendered the IL-2 inactive as it lost the activity in stimulating CTLL-2 cell proliferation ( FIG. 6 , lane 3). Since IL-2 is a pro-inflammation cytokine in human immune system, soluble CD26 may be useful as an inflammation inhibitor through its inhibition on IL-2 activity.
EXAMPLE 7
Neutralization of VEGF by Sera from Pregnant Females
Sera from 7 pregnant women were collected as described previously. One hundred microliters of serum were incubated with 1 ng of VEGF at 37° C. for 2 hours before performing the VEGF ELISA assay ( FIG. 7 , group 3). Sera from 7 men and 5 non-pregnant women were also collected and used as controls in the same experiment ( FIG. 7 , groups 1 and 2, respectively). As shown in FIG. 7 , only pregnant woman's serum prevented the detection of VEGF due to the presence of a soluble factor (i.e. sFlt-1).
EXAMPLE 8
Blood sFlt-1 Level Increases During Pregnancy
Measurement of Serum sFlt-1 Level
Ten milliliters of blood were taken from each volunteer blood donor. Blood was overlaid on 3 ml of Lymphoprep™ (Axis-Shield UK, CAT NO 1114545) and centrifuged for 20 minutes at 700×g. The top layer serum was harvested and aliquots were stored at −70° C. for the later ELISA assay. The amount of soluble Flt-1 in the serum was measured using sFlt-1 ELISA kit (R&D Systems CAT NO DVR100B) according to the manufacturer's instruction manual.
FIG. 8A illustrates the average amount of sFlt-1 from serum samples of 5 subjects. Lane 1: pregnant women; lane 2: non-pregnant women; lane 3: men. The results indicate that only significant amount of soluble Flt-1 could be detected in the serum of pregnant women (lane 1) as compared to that of non-pregnant women and men (lane 2 and 3).
FIG. 8B illustrates the level of sFlt-1 in the serum from a pregnant woman at 20 weeks of pregnancy (lane 1), 30 weeks of pregnancy (lane 2) and 10 weeks after giving birth (lane 3). The result indicates that the levels of soluble Flt-1 in the serum increased during the course of the pregnancy, but disappeared about 3 months after giving birth.
Angiogenesis has been implicated in progression of inflammatory arthritis, psoriasis, atherosclerosis as well as tumor growth and metastasis. Pathological angiogenesis is a hallmark of cancer and various ischaemic and inflammatory diseases. Angiogenesis is crucial for tumor growth and metastasis (Keith Dredge et al. Current Opinion in Investigational Drugs. 4 (6): 667-674, (2003)). New blood vessel development is an important process in tumor progression. It favors the transition from hyperplasia to neoplasia, i.e., the passage from a state of cellular multiplication to a state of uncontrolled proliferation characteristic of tumor cells. Neovascularization also influences the dissemination of cancer cells throughout the entire body eventually leading to metastasis formation. Ninety percent of all cancers are solid tumors and thus depend on angiogenesis to support their growth. It has also been shown that the resection of a primary tumor is often accompanied by metastases caused by a systemic disturbance of the angiogenic balance of the body. All these standard therapies could profit from a concomitant treatment that would restrict latent tumors in a prevascular phase.
It has been suggested inhibiting new blood vessel formation as a way to fight cancer. The malignant tissue would be deprived of its oxygen and nutrient supply, as well as be unable to eliminate metabolic wastes. This in turn would inhibit tumor progression and metastatic progression that accompanies most advanced cancers. There are five main steps of the angiogenic process that can be interrupted: (1) Inhibiting endogenous angiogenic factors, such as bFGF (basic Fibroblast Growth Factor) and VEGF (Vascular Endothelial Growth Factor); (2) Inhibiting degradative enzymes (Matrix Metalloproteinases) responsible for the degradation of the basement membrane of blood vessels; (3) Inhibiting endothelial cell proliferation; (4) Inhibiting endothelial cell migration; and (5) Inhibiting the activation and differentiation of endothelial cells.
Neutralization of VEGF has been used as a strategy for the treatment of cancer. For example, a new drug AVASTIN™, which is a monoclonal antibody, works by binding to and inhibiting the action of vascular endothelial growth factor (VEGF). VEGF is a substance that binds to its receptor on certain cells to stimulate new blood vessel formation. When VEGF is bound by AVASTIN™, it cannot stimulate the formation and growth of new blood vessels (angiogenesis). AVASTIN™ enhances the effects of chemotherapy, but does not appear to be very effective when given alone in patients with colorectal cancer.
The present invention discloses, among others, that soluble Flt-1 is capable of neutralizing VEGF. Since anti-VEGF or anti-angiogenesis has been proved to be useful in treating angiogenesis-dependent cancer, sFlt-1 by its VEGF-neutralizing activity may be useful for treating cancer or tumor of which the growth is dependent on angiogenesis.
Inflammation has also been implicated in Cancer. Chronic inflammation is associated with cancer development. Early and persistent inflammatory responses observed in or around developing neoplasms regulate many aspects of tumor development. (Leon C. L. et al. “Inflammation, proteases and cancer.” European Journal of Cancer, Vol. 42, Issue 6, pages 728-734) Inflammation functions at all three stages of tumor development: initiation, progression and metastasis. Inflammation contributes to initiation by inducing the release of a variety of cytokines and chemokines that alert the vasculature to release inflammatory cells and factors into the tissue milieu, thereby causing oxidative damage, DNA mutations, and other changes in the microenvironment, making it more conducive to cell transformation, increased survival and proliferation. Moreover, there is a strong association between chronic inflammation and cancer. An appreciation of the importance of inflammation has already led to clinical trials of anti-inflammatory drugs (e.g., COX-2 inhibitors) for cancer prophylaxis and treatment. (National Cancer Institute, Division of Cancer Biology, “Executive Summary of Inflammation and Cancer Think Tank.” [retrieved on 2007-11-17]. Retrieved from the Internet:<URL: http://dcb.nci.nagov/thinktank/Executive_Summary_of_Inflammation_and_Cancer_Thi nk_Tank.cfm>)
Angiogenesis is also associated with inflammation or inflammatory disorders. Vascular endothelial growth factor (VEGF) has been shown to a have a central involvement in the angiogenic process in rheumatoid arthritis (RA). The additional activity of VEGF as a vascular permeability factor may also increase oedema and hence joint swelling in RA. Several studies have shown that targeting angiogenesis in animal models of arthritis ameliorates disease. (Paleolog E M. Arthritis Res. 2002; 4 Suppl 3:S81-90.) Since sFlt-1 has anti-angiogenesis/anti-VEGF activity, it may also be useful for reducing the degree of angiogenesis in inflammatory diseases including rheumatoid arthritis as well as in chronic inflammation which is associated with cancer.
It has been reported that pregnancy induces immunological alterations. A variety of hormonal and immunological alterations are induced by pregnancy in order to protect semi-allogenic fetus from rejection. Systemic effects of altered immunoregulation induced by pregnancy influence the activity of rheumatoid arthritis (RA) and other autoimmune disease. Pregnancy induces improvement or even remission of disease activity in 75% of RA patients. The increase of circulating inhibitors of proinflammatory cytokines occurring in pregnancy could act as a potent anti-inflammatory agent in joint inflammation. It is likely that neutralization of proinflammatory cytokines may be the key to remission. (Ostensn M, Villiger P M, “Immunology of Pregnancy-pregnancy as a remission inducing agent in rheumatoid arthritis.” Transpl Immunol. 2002 May; 9(2-4): 155-60.)
The present invention describes, among others, soluble Flt-1 was detected in large amount only in pregnancy. Since VEGF is implicated in RA and sFlt-1 is capable of neutralizing VEGF, an increase in the levels of serum sFlt-1 in pregnancy is likely to be one of the factors that contribute a remission of RA during pregnancy. Moreover, sCD26 is produced by trophoblast cells, which may in turn neutralize inflammatory cytokines such as interleukins, thereby further contributing a remission of RA during pregnancy.
Soluble CD26/DPPIV has an essential role in immune regulation as a T cell activation molecule and a regulator of chemokine function. It has been suggested that sCD26 may exert its enhancing effect on T cell response to recall antigen via its effect on antigen-presenting cells. Studies have shown that sCD26 is transported into monocytes and upregulates the expression of CD86 on monocytes through its DPPIV activity, both at the protein and mRNA levels. It has been therefore suggested that sCD26, particularly its DPPIV enzymatic activity, enhance T cell immune response to recall antigens through its direct effect on antigen-presenting cells (Dang and Morimato, Histol Histopathol. 17: 1213-1226 (2002)). Clinical studies have shown that plasma levels of DPPIV/CD26 from rheumatoid arthritis patients were significantly decreased when compared to those from osteoarthritis patients (Nathalie Busso et al., American Journal of Pathology, Vol. 166, No. 2, 433-442 (2005)).
The present invention discloses, among others, that sCD26 is produced by trophoblast cells. Moreover, the invention discloses sCD26 is capable of inhibiting Interleukins, such as IL-2. Therefore, sCD26 may be useful for anti-inflammation in diseases including cancer, rheumatoid arthritis, and other inflammatory disorders, in addition its T-cell activation activities as aforementioned.
All of the references cited herein are incorporated by reference in their entirety.
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. | Pharmaceutical compositions and methods for treating diseases associated with angiogenesis and inflammation. The invention relates to a pharmaceutical composition that includes a therapeutically effective amount of sCD26 and/or a biologically active derivative thereof and a pharmaceutically acceptable carrier. The composition may further include a therapeutically effective amount of sFlt-1 and/or a biologically active derivative thereof. Additionally, the invention relates to methods for treating a disease associated with and/or progresses by an inflammatory cytokine-associated inflammation and/or VEGF-associated angiogenesis. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. §119(a) of German Patent Application No. 10 2012 001 703.0 filed Jan. 31, 2012, the disclosure which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention relate to a gear wheel and in particular a gear wheel which includes several components. The gear wheel according to embodiments of the invention can be used particularly advantageously in connection with stepper motors on satellites. However, use of the gear wheel is not limited to this field of application, but can be used advantageously in any arrangement or assembly in which the influence of vibrations, in particular micro-vibrations, should or has to be reduced or minimized.
[0004] 2. Discussion of Background Information
[0005] With the use of stepper motors in arrangements or assemblies, micro-vibrations (micro jitter) are caused by the cogging torque of the rotor. These micro-vibrations are transmitted to the structural parts of the arrangement or the assembly. This leads for example to disturbances in the arrangement or assembly in particular in the instruments thereof or to directing errors. The micro-vibrations are produced for example by permanent magnets in the rotating part of the motor and transmitted as accelerations via the gear wheel to the arrangement or assembly.
SUMMARY OF THE EMBODIMENTS
[0006] Embodiments of the invention provide a gear wheel structured so that the effects of vibrations, in particular of micro-vibrations, are reduced.
[0007] According to embodiments, the gear wheel includes an inner part, which is connected to a cause of vibrations, a connection element and a ring gear. The connection element is embodied or formed so that the vibrations caused are reduced.
[0008] The gear wheel according to embodiments includes an inner part, which is connected to a causer or source of vibrations, in particular micro-vibrations, e.g., a drive shaft of a motor, in particular a stepper motor on a satellite, a connection element and a ring gear. The connection element is embodied or formed so that the vibrations, in particular micro-vibrations, caused are reduced. To this end in particular, the connection element can be connected to the inner part of the gear wheel and the ring gear in a non-positive manner. The invention advantageously reduces vibrations, in particular micro-vibrations, which act on the ring gear.
[0009] According to embodiments, the connection element of the gear wheel can be embodied or formed as a spring sheet. It is particularly advantageous when the spring sheet is produced from aluminum, titanium or spring steel. It is furthermore particularly advantageous when the spring sheet has a thickness of at least 0.1 mm.
[0010] According to further embodiments, the connection element of the gear wheel can be embodied or formed as a cast plastic ring. It is particularly advantageous when the plastic ring is produced from an elastic synthetic material, e.g., RTV plastic, silicone or a resin system. It is furthermore particularly advantageous if the plastic ring has a thickness of at least 1/10 mm to several millimeters.
[0011] Embodiments of the invention are directed to a gear wheel that includes an inner part, which is connectable to a cause of vibration, a connection element and a ring gear. The connection element is structured and arranged to reduce vibrations.
[0012] According to embodiments of the invention, the connection element can be coupled to the inner part and to the ring gear in a non-positive manner.
[0013] In accordance with embodiments, the connection element can be structured and arranged as a spring sheet. The spring sheet may include at least one of aluminum, titanium and spring steel. Further, the spring sheet can have a thickness of at least 0.1 mm.
[0014] Moreover, the connection element may include a cast plastic ring. The plastic ring can include elastic synthetic material. The elastic synthetic material may include at least one of RTV plastic, silicone and a resin system. Further, the plastic ring can have a thickness of at least 1/10 mm.
[0015] In embodiments, the inner part can be connectable to a motor via a drive shaft. The motor can be a stepper motor on a satellite.
[0016] According to other embodiments, the vibrations can be micro-vibrations and the cause of the vibrations can be a motor of a satellite.
[0017] Embodiments of the invention are directed to a gear wheel for connection to a vibrating shaft of a motor. The gear wheel includes an inner part coupleable to the vibrating shaft, a ring gear surrounding the inner part and a connection element structured and arranged to couple the inner part to the ring gear so as to reduce an amplitude of vibrations in the vibrating shaft transmitted to the ring gear.
[0018] According to embodiments, the vibrations in the vibrating shaft may be micro-vibrations.
[0019] In accordance with other embodiments, the motor can be structured for use in a satellite.
[0020] According to still other embodiments, the motor may include a stepper motor in a satellite.
[0021] In further embodiments, the connection element can have a radial thickness of about 0.1 mm and may include one of spring sheet and a cast plastic ring. Moreover, when the connection element is spring sheet, the spring sheet can include at least one of aluminum, titanium and spring steel. When the connection element is a cast plastic ring, the cast plastic ring can include at least one of RTV plastic, silicone and a resin system.
[0022] Embodiments of the invention are directed to a method for reducing vibrations transmitted by a rotating shaft. The method includes connecting a gear wheel to the rotating shaft, the gear wheel having a vibration damping element coupling an inner part for connection to the rotating shaft to a ring gear separated from the inner part.
[0023] In accordance with still yet other embodiments of the present invention, the vibrations transmitted by the rotating shaft can be micro-vibrations in a satellite.
[0024] Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
[0026] FIG. 1 illustrates an embodiment of the gear wheel including a plastic ring; and
[0027] FIG. 2 illustrates an embodiment of the gear wheel including spring sheet.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied or formed in practice.
[0029] FIG. 1 shows an embodiment of the gear wheel. According to the embodiment, the gear wheel can include three parts, i.e., an inner part ( 1 ) of the gear wheel, a connection element ( 2 ) of the gear wheel and a ring gear ( 3 ) of the gear wheel.
[0030] The inner part ( 1 ) of the gear wheel can be embodied or formed so that it can be connected, e.g., to a motor via a drive shaft. The motor and/or the drive shaft identified are merely exemplary possible devices or elements causing or acting as sources for vibrations, and more particularly for micro-vibrations. However, it is understood that any number of devices causing or acting as sources for vibrations and/or micro-vibrations are known and can be associated with the exemplary gear wheel without departing from the spirit and scope of the embodiments. Thus, it is understood that the embodiments of the invention can likewise be applied and used in combination with such other causes or sources of vibrations, in particular micro-vibrations.
[0031] The connection element ( 2 ) is embodied or formed such that the vibrations, in particular micro-vibrations, which are caused, e.g., by the drive shaft of the motor and act on the ring gear ( 3 ), are reduced by the reduced stiffness (inertia of the system). To this end, the connection element ( 2 ) according to the invention is connected to the inner part ( 1 ) and the ring gear ( 3 ) in a non-positive manner. The reduction factor achieved thereby depends on the thickness and the stiffness of the connection element ( 2 ).
[0032] According to the embodiments, the stiffness of the connection element ( 2 ), which can be embodied or formed, e.g., as individual sheets or ring, can be of particular significance.
[0033] According to the embodiment in FIG. 1 , the connection element ( 2 ) of the gear wheel is embodied or formed as a cast plastic ring. The plastic ring serves as a force transmission element. According to the invention, it is particularly advantageous if the plastic ring is produced from an elastic synthetic material, e.g., RTV plastic (RTV-S=961) silicone or resin systems. For advantageous reduction properties, the thickness of the plastic ring should be between 1/10 mm up to several millimeters.
[0034] It is a technical advantage of this embodiment that the amplitude of the vibrations, in particular micro-vibrations, is reduced to a lower level. By way of example, ten times lower amplitudes are achieved as compared to the case without the plastic ring. In this way, the effect of the vibrations, in particular micro-vibrations, of the motor on instruments of a device, e.g., of a satellite, and on the device can thus be minimized.
[0035] According to the embodiment in FIG. 2 , the connection element of the gear wheel ( 2 ) is embodied or formed as a spring sheet. The spring sheet serves as a force-transmitting element. By way of example, connection element ( 2 ) can be milled out of the gear wheel or inserted into grooves. According to the embodiments, it is particularly advantageous if the spring sheet is produced from aluminum, titanium or spring steel. For advantageous oscillation properties, the thickness of the spring sheet should be at least 0.1 mm.
[0036] A technical advantage of this embodiment is that the amplitude of vibrations, in particular micro-vibrations, is reduced to a lower level. For example, ten times lower amplitudes are achieved as compared to the case without spring sheet. The effect of the vibrations, in particular micro-vibrations, of the motor on instruments of a device, e.g., a satellite and on the device can thus be minimized.
[0037] It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. | Gear wheel and method for reducing vibrations transmitted by a rotating shaft. The gear wheel includes an inner part, which is connectable to a cause of vibration, a connection element and a ring gear. The connection element is structured and arranged to reduce vibrations. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a method for producing a control panel fascia, particularly for heating the cockpit of a vehicle, intended to have at least one rotary knob, comprising a mounting plate which defines a front face of the fascia and, for each knob, a tubular wall extending backwards from the mounting plate and meeting the latter along the edge of an approximately circular opening formed therein, the tubular wall having, in succession, in the axial direction, a first region adjacent to the opening and having approximately the same radius thereof, housing a head of the knob over at least part of the axial length thereof, and a second region of smaller radius than the head, meeting the first region at a shoulder, housing and guiding the rotation of a guide stalk of the knob, the head and the front face, near the opening, carrying marks and/or symbols which can be brought to face each other depending on the position into which the knob is turned, and which may be illuminated, through the material of the knob and the fascia, from a light source placed behind this fascia.
The term "radius" here denotes a distance with respect to an axis, which can vary in the circumferential direction when the element in question is not strictly circular. In this case, the inequalities mentioned for the radii of various elements need to be verified all around the axis.
The expression "front face" denotes that face of the mounting plate which faces towards the user of the control panel, and the terms "front" and "rear" refer to this convention. Note that in the case of a vehicle heating control panel, the front face generally faces the rear of the vehicle.
Forming the front face of the mounting plate with a film of transparent thermoplastic material which is inked by silkscreen printing to form colored marks and/or symbols and to make the rest of the surface opaque is known. The shoulder of the tubular wall, which is behind the head of the knob, must allow light from the light source through to illuminate at least one mark present on the head and intended to come to face various symbols depending on the position into which the knob is turned. By contrast, light must not pass around the head of the knob, between this head and the first region of the tubular wall.
To achieve this, it has been proposed that the tubular wall be made of transparent material, and that the silkscreen printed film be dished in such a way that it also covers part of the internal face of the tubular wall, as far as up behind the annular gap between the first region of this wall and the head. However, this has led to a deformation of the symbols and marks during the dishing operation, and to tearing and cracking of the film, leading to a high reject rate.
SUMMARY OF THE INVENTION
The object of the invention is to overcome the aforementioned drawbacks.
The invention aims particularly at a method of the kind defined in the introduction, and envisages that the fascia be obtained using the following steps:
a) a monolayer flat film of a first thermoplastic material, which has at least one opening slightly smaller than the opening to be formed in the mounting plate and carrying, near this opening, the marks or symbols to be obtained on the front face, is placed in a mold, the film being pressed onto a plate formed by a first element of the mold and being pushed tightly, along the edge of its opening, around a boss of the first element which projects from the plate;
b) an opaque second thermoplastic material is injected into an annular cavity of the mold surrounding the boss and containing an annular zone of the film adjacent to the opening, which zone is pressed by the injected material against the plate and against the boss, the film being trapped in the mold so that it is impervious to the material injected, around the annular zone, and the mold being sized in such a way that the film defines the front face of the mounting plate and that the second material injected defines part of the tubular wall, limited to a fraction of its thickness, adjacent to its internal face, and ending at the rear in an axial opening of radius slightly smaller than that of the head;
c) a light-conducting third thermoplastic material is injected onto the part-finished item obtained in step b) in order to complete the thickness of the mounting plate and the tubular wall, the chemical nature and the temperature of injection of each of the second and third thermoplastic materials being chosen such that this material binds securely, when it is injected, to the previous one or to the previous ones without deforming it (or them).
Optional additional or alternative features of the invention are listed below:
d) an opaque fourth thermoplastic material is injected onto the part-finished item obtained in step c) in order to form a peripheral rim of the fascia extending backwards from the mounting plate, the chemical nature and the temperature of injection of the fourth thermoplastic material being chosen such that this material binds securely, when it is injected, to the first and third thermoplastic materials, without deforming them.
The rear face of the film remains uncovered by the third material during step c), and is covered by the fourth material during step d), over a peripheral region so as to strengthen the bond between the film and the fourth material.
The first material is based on polycarbonate, the second material is based on a blend of polycarbonate and ABS, the third material is based on at least one polymer chosen from polymethyl methacrylate and polycarbonate, and the fourth material, if there is one, is based on ABS.
The temperatures at which the successive materials are injected are about 280° C. for step b), 240° C. for step c), and, as appropriate, 230° C. for step d).
The first material is more or less transparent and colored marks and/or symbols and/or opaque areas are formed by silkscreen printing on the front face of the film prior to step a).
The film is cut from a flat sheet and defines, for the mounting plate, a front face which is flat or derives from a flat surface by bending without stretching or contraction along the surface.
DESCRIPTION OF THE DRAWINGS
The features and advantages of the invention will be explained in greater detail in the description which follows, with reference to the appended drawings, in which:
FIG. 1 is a cross-section, on I--I of FIG. 2, of the fascia of a control panel according to the invention, on which a knob is mounted;
FIG. 2 is a front view of the assembly of FIG. 1;
FIG. 3 is a front view of a cut and silkscreen printed film intended to form the front face of the fascia;
FIGS. 4, 5, 7 and 9 are cross-sectional views showing successive steps in the manufacture of the fascia;
FIGS. 4A and 5A are enlarged details of FIGS. 4 and 5 respectively; and
FIGS. 6, 8 and 10 are cross-sectional views showing the part-finished items and the finished fascia obtained on completion of the steps of FIGS. 5, 7 and 9 respectively.
DETAILED DESCRIPTION OF THE INVENTION
The fascia 1 depicted in FIGS. 1 and 2 comprises a flat mounting plate 2 with three circular openings of the same radius 3, 4 and 5 aligned with each other. The mounting plate 2 has an elongate shape in the direction in which the openings are aligned, this plate being delimited by straight upper and lower longitudinal edges 6, 7 and two convex semicircular ends 8 and 9. Along the edge of each of the openings 3, 4 and 5, the mounting plate meets a tubular wall 10 extending backwards, comprising a first region 11 which is slightly frustoconical, narrowing from the mounting plate, then a flat radial shoulder 12 coming in towards the axis 13 of the opening and of the tubular wall from the region 11, and finally a region 14 once more extending away from the plane of the mounting plate from the shoulder 12, the region 14 having a cylindrical internal face and an external face which is slightly frustoconical to make demolding easier. The region 14 guides the rotation of the cylindrical stalk 15 of a knob 16, the latter also comprising a head 17 formed of a flat flange 18 of circular outline, housed radially inside the region 11 of the tubular wall 10 and of a diametral rib 19 projecting forward from the opening 3. To simplify the drawing, just one knob 16 is shown, associated with the opening 3. However, the complete control panel has a similar knob corresponding to each opening 4 and 5.
The fascia 1 also has a peripheral rim 22 extending backwards from the perimeter of the mounting plate 2.
As can be seen in FIG. 2, symbols 23 appear on 20 the front face of the mounting plate 2, around each of the openings 3, 4 and 5. Furthermore, the rib 19 of the knob 16 at one of its diametral ends has a mark 24 in the shape of an arrowhead. This knob, and identical knobs associated with the openings 4 and 5, can be placed in different angular positions about axes 13 so that the marks 24 come to face various symbols 23. The symbols and marks are illuminated, through the fascia and the knobs, from one or more light sources, not depicted, placed behind the mounting plate 2. Because of the position of the marks 24, the light which reaches them has to pass through the shoulders 12 of the tubular walls. By contrast, no light must emerge through the annular gap 25 between the flange 18 of this knob and the region 11 of the corresponding tubular wall. Likewise, light must not pass through the rim 22 and form a luminous halo around the fascia 2.
To produce the fascia 1, the starting point is the part-finished item illustrated in FIG. 3, cut from a flat monolayer film of transparent polycarbonate 0.3 mm thick, available commercially, so as to have the contour of the mounting plate 2 as described above, and three circular openings 3a, 4a and 5a laid out like the openings 3, 4 and 5 and of a diameter very slightly smaller than that of these openings. The front face of the part-finished item 30 is inked by silkscreen printing to form the symbols 23 and to color the rest of the surface in black and make it opaque. The inked front face of the part-finished item 30 is pressed onto a metal plate 31 from which there project three axisymmetric bosses 32 which forcibly penetrate the openings 3a, 4a and 5a, deforming and parting from the plate 31 an annular zone 33 of the part-finished item surrounding each of these openings, as shown in FIGS. 4 and 4A. Next, as shown in FIGS. 5 and 5A, the male mold part consisting of the plate 31 equipped with the bosses 32 is associated with a female part 34 to define, around each boss, an annular cavity 35 containing the annular zone 33. An opaque blend of polycarbonate and of acrylonitrile-butadiene-styrene copolymer (ABS) is injected into this cavity. The injected material presses the annular zone 33 against the plate 31 and the base of the boss 32, and wets the rear face of this zone. The presence of polycarbonate in the blend makes it possible to ensure good adhesion between the injected-material and the film of polycarbonate. The presence of ABS allows injection to be performed at a temperature, 280° C., which is low enough to avoid deforming the film. This material is also able to withstand the testing, especially the climatic testing (90° C. and 95% humidity) laid down in motor-vehicle manufacturer technical specifications. Around the zone 33, the part-finished item 30 is trapped between the two mold parts so as to limit the flow of the injected material.
FIG. 6 shows the annular element 36 molded in polycarbonate/ABS around the opening 3 and, in part, the element molded around the opening 4.
The part-finished item 37 thus obtained is transferred to a second mold (FIG. 7) made up of a male part 40 in the form of a plate with three bosses 41 and of a female part 42, which parts between them delimit a cavity 43. The part-finished item 37 is housed in this cavity, pressed against the male part 40 and 41. The geometric shape of the cavity corresponds to that of the fascia 1 to be produced, except in regard to the periphery of this fascia, as will be seen in detail later.
Transparent polymethyl methacrylate at a temperature of 240° C., at which no degradation and no deformation of the part-finished item 37 occur, is injected into that part of the cavity 43 which is not occupied by the part-finished item 37. This material is also able to withstand the testing imposed by motor-vehicle manufacturer technical specifications.
The part-finished item 50 thus obtained, illustrated in FIG. 8, is then placed in the cavity 51, which it almost completely fills, of a third mold (FIG. 9) made up of a male part 52 and of a female part 53. The geometric shape of the cavity 51 exactly corresponds to that of the fascia 1 to be produced. The part-finished item 50 leaves free only a peripheral annular region of L-shaped profile, one leg 54 of which L corresponds to the rim 22 of the fascia and the other leg 55 of which extends along the rear face of the film 30, between the leg 54 and the peripheral edge 56 of the element 57 formed by injection into the mold of FIG. 7, the edge 56 being, as can be seen in FIG. 8, set back slightly from the peripheral edge of the film 30. Black ABS at a temperature of 230° C., at which temperature no damage to the part-finished item 50 occurs, is injected into the remaining cavity 54 and 55.
FIG. 10 shows how the various constituent materials of the fascia are arranged geometrically, thanks to appropriate sizing of the molds used.
The film 30 covers all of the front face of the mounting plate 2, and the rounded region which connects this face to the internal face of the tubular wall 10, to the edge of each of the openings 3, 4 and 5. Each polycarbonate/ABS annular element 36 defines the internal face of the corresponding tubular wall, as a continuation of the film 30, over the entire axial length of the region 11, over the rounded region connecting the latter to the shoulder 12, and over the peripheral part of this shoulder, beyond the radius of the axial opening 38 of the element 36. The polymethacrylate element 57 forms the rest of the tubular walls 10, that is to say the rest of the thickness of these beyond the opening 38, and all of its thickness up to these openings, as well as the rest of the thickness of the mounting plate 2, as far as the edge 56 placed a small distance from the peripheral edge of the mounting plate. Finally, the annular ABS element 58, with an L-shaped profile, forms the rest of the thickness of the mounting plate beyond the edge 56 and the rim 22.
The transparent element 57, which constitutes all of the thickness of the shoulder 12 of the tubular wall 10, inside the axial opening 38 of the element 36, allows light to pass to illuminate the marks 24 on the knobs. By contrast, the opaque element 36 prevents light from reaching the annular gap 25 between the flange 18 of the knob and the region 11 of the tubular wall. The element 58, which is also opaque, prevents light from passing around the periphery of the fascia.
Depending on the control panel surroundings, the presence of the opaque rim 22 may prove unnecessary. In this case, the element 57 is extended as far as in line with the peripheral edge of the film 30 and step d) is omitted. Instead of being carried out separately as described, this step d) may also be carried out at the same time as step b), using the same material, if the component design allows this.
Furthermore, instead of being flat, the front face of the mounting plate 2 may have a convex or concave curvature, about one or two axes, obtained and stabilized by the successive overmoldings. | The fascia of a vehicle heating control panel is obtained by overmolding onto a monolayer flat film made of polycarbonate, elements made of different thermoplastic materials so as to allow marks and/or symbols formed by silkscreen printing on the film and present on a rotary knob to be illuminated by a transparency, while at the same time preventing the leaking of light. | 1 |
PRIORITY
The present invention claims priority under 35 USC section 119 based on provisional application 60/772,367 on Feb. 10, 2006.
CROSS REFERENCE TO RELATED APPLICATIONS
This utility application is the Continuation-In-Part application of the nonprovisional utility U.S. patent application Ser. No. 11/052,542 filed Feb. 7, 2005 which claims benefit of patent application Ser. No. 10/764,793 filed on Jan. 26, 2004, (now U.S. Pat. No. 6,857,422) which claims benefit from the U.S. Provisional Application Nos. 60/477,591 filed on Jun. 12, 2003 and 60/517,069 filed on Nov. 5, 2003, and 60/772,367 filed Feb. 10, 2006 each of which are herein incorporated by reference in their entirety.
BACKGROUND OF INVENTION
This invention relates to an improvement to pneumatic guns, air rifles, pellet rifles, paintball guns and the like. Such pneumatic guns are typically driven by either hand or electrically cocked springs, compressed gas, or hand operated pumps and suffer from a number of disadvantages outlined in more detail below.
Air rifles have been around for many years and have seen numerous evolutionary changes over the years. The most common methods for propelling the projectile use the energy from compressed gas or from a spring. There are four major techniques shown in the prior art for launching the projectile with many variations based upon such teachings. These techniques include: (i) the use of stored compressed gas in the form of carbon dioxide cylinders or other high pressure storage tanks; (ii) using a powerful spring to push a piston which compresses air which then pushes the projectile; (iii) using a hand pump to pressurize the air for subsequent release; and (iv) using a direct acting means such as a solenoid plunger or centrifugal force to push the projectile out of the barrel. All of these methods have distinct disadvantages when compared to the present invention.
The first technique requires a source of compressed air, such as a tank or canister. Filling, transporting and using such a canister represents an inconvenience and potential safety hazard for the user. Often, additional equipment such as regulators, evaporation chambers, and other controls are required to reduce the pressure in the cylinder to a level suitable for launching the projectile. This peripheral equipment increases the cost and complexity of such an air gun. Additionally, for carbon dioxide driven air or paintball guns, the velocity of the projectile can vary significantly depending on the canister temperature. Furthermore, these tanks store a large amount of energy which, can be suddenly released through a tank fault, creating a potential safety issue. Additional teachings such as those contained in U.S. Pat. Nos. 6,516,791, 6,474,326, 5,727,538 and 6,532,949 teach of various ways of porting and controlling high pressure air supplies to improve the reliability of air guns (specifically paintball guns and the like) by differentiating between the air stream which is delivered to the bolt which facilitates chambering the projectile and the air stream which pushes the projectile out of the barrel. All of these patents still suffer from the major inconvenience and potential safety hazard of storing a large volume of highly compressed gas within the air gun. Additionally, as they combine electronic control with the propulsion method of stored compressed gas, the inherent complexity of the mechanism increases, thus, increasing cost and reliability issues. An additional teaching in this area in U.S. Pat. No. 6,142,137 shows an electrical means to assist in the trigger control of a compressed air gun. In this patent, an electromotive device is used in conjunction with electronics to define various modes of fire control such as single shot, burst or automatic modes. This addresses the ability of multiple modes of fire, but does not solve the fundamental propulsion issues of safety and inconvenience associated with gas cylinders.
A second technique which has been used for quite a few years in many different types of pellet, “bb” or air rifles has a basic principle of storing energy in a spring which is subsequently released to rapidly compress air. The highly compressed air created by a spring acting on a piston pushes the projectile out of the barrel at high velocity. Problems with this method include the need to “cock” the spring between shots thus limiting its use to single shot devices and low rates of fire. Furthermore, the unwinding of the spring results in a double recoil effect. The first recoil is from the initial forward movement of the spring, but a second recoil occurs when the spring slams the piston into the end of the cylinder (i.e. forward recoil). Additionally, spring air rifles require a significant amount of maintenance and, if dry-fired, the mechanism is easily damaged. Finally, the effort required for such “cocking” is often substantial and can be difficult for many individuals. References to these style air guns can be found in U.S. Pat. Nos. 3,128,753, 3,212,490, 3,523,538, and 1,830,763. Additional variations on the above technique have been attempted through the years including using an electric motor to cock the spring that drives a piston. This variation is detailed in U.S. Pat. Nos. 4,899,717 and 5,129,383. While this innovation solves the problem of cocking effort, the resulting air rifle still suffers from a complicated mechanism, double recoil and maintenance issues associated with the spring piston system. Another mechanism which uses a motor to wind a spring is shown in U.S. Pat. Nos. 5,261,384 and 6,564,788. Herein, a motor is used to compress a spring which is connected to a piston. The spring is subsequently quickly released allowing it to drive a piston compressing air which pushes a projectile out the barrel. This implementation still suffers from similar limitations inherent in the spring piston systems. Hu teaches of using a motor to wind a spring in these patents. Because there is no compression valve, the spring must quickly compress the air against the projectile to force it out the barrel at good velocity. This requires a strong spring to rapidly compress the air when the mechanism releases. Springs in such systems are highly stressed mechanical elements that are prone to breakage and which increase the weight of the air gun. A further disadvantage of Hu's teaching is that the spring is released from the rack pinion under full load causing the tips of the gear teeth to undergo severe tip loading. This causes high stress and wear on the mechanism especially the gear teeth. This is the major complaint for those guns in the commercial market and is a major reliability issue with this style mechanism. A further disadvantage of this type of mechanism is that upon scale up to accept larger projectiles or projectile with more energy, there occurs much increased wear and a forward recoil which is the result of the piston impacting the front end of the cylinder. In a dry fire (no projectile), the mechanism can be damaged as the piston slams against the face of the cylinder. Hu teaches use of a breech shutoff, that is common in virtually all toy guns since the air must be directed down the barrel and the flow into the projectile inlet port must be minimized. Hu specifically does not incorporate an air compression valve in his patents which is a restrictive valve against which the piston compresses the air for subsequent release. Thus, forward recoil, high wear and low power are drawbacks in these types of mechanisms. A similar reference can be seen in U.S. Pat. No. 1,447,458 which shows a spring winding and then delivery to a piston to compress air and propel a projectile. In this case, the device is for non-portable operation.
The third technique, using a hand pump to pressurize the air, is often used on low end devices and suffers from the need to pump the air gun between 2 to 10 times to build up enough air supply for sufficient projectile velocity. This again limits the air rifle or paintball gun to slow rates of fire. Additionally, because of the delay between when the air is compressed and when the compressed air is released to the projectile, variations in the projectile velocity are quite common in these style air guns. Further taught in U.S. Pat. Nos. 2,568,432 and 2,834,332 is a method to use a solenoid to directly move a piston which compresses air and forces the projectile out of the air rifle. While this solves the obvious problem of manually pumping a chamber up in order to fire a gun, these devices suffer from the inability to store sufficient energy in the air stream. Solenoids are inefficient devices and can only convert very limited amounts of energy due to their operation. Furthermore, since the air stream is coupled directly to the projectile in this technique as it is in spring piston designs, the projectile begins to move as the air is being compressed. This limits the ability of the solenoid to store energy in the air stream to a very short time period and further relegates its use to low energy air rifles. In order to improve the design, the piston must actuate in an extremely fast time frame in order to prevent significant projectile movement during the compression stroke. This results in a very energetic piston mass similar to that shown in spring piston designs and further results in the undesirable double recoil effect as the piston mass must come to a halt. Additionally, this technique suffers from dry-fire in that the air is compressed between the piston and the projectile. A missing projectile allows the air to communicate to the atmosphere through the barrel and can damage the mechanism in a dry-fire scenario. Another variant of this approach is disclosed in U.S. Pat. No. 1,375,653, which uses an internal combustion engine instead of a solenoid to act against the piston. Although this solves the issue of sufficient power, it is no longer considered an air rifle as it becomes a combustion driven gun. Moreover, it suffers from the aforementioned disadvantages including complexity and difficulty in controlling the firing sequence. Further taught in U.S. Pat. Nos. 4,137,893 and 2,398,813 to Swisher is the use of an air compressor coupled to a storage tank which is then coupled to the air gun. Although this solves the issue of double recoil, it is not suitable to a portable system due to inefficiencies of compressing air and the large tank volume required. This type of system is quite similar to existing paintball guns in that the air is supplied via a tank and not compressed on demand. Using air in this fashion is inefficient and not suitable for portable operation since much of the air compression energy is lost to the environment thru the air tank via cooling. Forty percent or more (depending on the compression ratio) of the compressed air energy is stored as heat and is lost to do work when the air is allowed to cool. Furthermore, additional complexity and expense is required to regulate the air pressure from the tank so that the projectile velocity is repeatably controlled. A variation of the above is to use a direct air compressor as shown in U.S. Pat. No. 1,743,576. Again, due to the large volume of air between the compression means and the projectile, much of the heat of compression is lost leading to inefficient operation. Additionally, this patent teaches of a continuously operating device which suffers from a significant lock time (time between trigger pull and projectile leaving the barrel) as well as the inability to run in a semiautomatic or single shot mode. Further disadvantages of this device include the pulsating characteristics of the air stream which are caused by the release and reseating of the check valve during normal operation.
The fourth technique is to use direct mechanical action on the projectile itself. The teachings in U.S. Pat. Nos. 1,343,127 and 2,550,887 represent such mechanisms. Limitations of this approach include difficulty in achieving high projectile velocity since the transfer of energy must be done extremely rapidly between the impacting hammer and the projectile. Further limitations include the need to absorb a significant impact as the solenoid plunger must stop and return for the next projectile. This causes a double-recoil or forward recoil. Since the solenoid plunger represents a significant fraction of the moving mass (i.e. it often exceeds the projectile weight), this type of system is very inefficient and limited to low velocity, low energy air guns as may be found in toys and the like. Variations of this method include those disclosed in U.S. Pat. No. 4,694,815 in which a hammer driven by a spring contacts the projectile. The spring is “cocked” via an electric motor, but again, this does not overcome the prior mentioned limitations.
All of the currently available devices suffer from one or more of the following disadvantages:
1. Manual operation by cocking a spring or pumping up an air chamber. 2. Difficult to selectively perform single fire, semiautomatic, burst or automatic modes. 3. Inconvenience, safety and consistency issues associated with refilling, transport and use of high-pressure gas or carbon dioxide cylinders. 4. Non-portability and low efficiency. Carnival air rifles and the like are tethered to a compressed air supply powered by a compressor which loses a significant portion of the energy of compression to heat loss from the air tank thus making battery operation impractical. 5. Forward recoil effects, high wear, and dry fire damage associated with spring piston and electrically actuated spring piston designs. 6. Complicated mechanisms associated with electrically winding and releasing a spring piston design resulting in expensive mechanisms with reliability issues. 7. Inefficient use and/or coupling of the compressed air to the projectile resulting in low energy projectiles and large energy input requirements.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a piston is driven by a rack and pinion mechanism to compress air within a cylinder against a mechanical compression valve. During the forward stroke of the piston, the bolt is moved forward enough to chamber the projectile and close off the projectile inlet port. At predetermined release position, the mechanical valve opens releasing high-pressure air thru the air passageways behind the projectile forcefully launching the projectile out the barrel. The piston and rack assembly then disconnects from the rack pinion and is reset to its initial position via a return spring. The return spring plays little or no part in the compression of the air for propelling the projectile and can be of small size. During the return of the piston to its initial position, a check valve replenishes the air to the air cylinder. An electric motor, which derives its power from a rechargeable battery pack, is coupled, to the rack thru a reduction mechanism and rack pinion. The rack and piston assembly is coupled to a bolt such that the bolt moves in cooperation with the movement of the piston. This coupling preferably includes springs and sliding members to reduce the travel of the bolt to a fractional percentage of the overall piston movement and to limit the force that the bolt can exert in shutting off the projectile inlet port. Shutting off the projectile feed port is a near separate and independent function and is not to be confused with the function performed by the compression valve.
Accordingly, besides the objects and advantages of the portable electric air gun as described, several objects and advantages of the present invention are:
1. To provide an electric motor driven gun with increased safety as the energy is stored electrically and available on demand and not stored in high pressure cylinders. 2. To provide an apparatus in which the operation is portable eliminating any tethering of hoses or cords. 3. To provide an electric motor driven air gun in which the piston is prevented from impacting the cylinder end thus eliminating double recoil. 4. To provide an apparatus in which the control of the projectile is enabled by electronic apparatus thus increasing the safety profile and speed control. 5. To provide an electric motor driven gun in which the source of energy is a rechargeable power supply eliminating the use of disposable or refillable gas pressure cylinders thus increasing convenience, safety and reducing operating cost. 6. To provide an electric motor driven gun which does not use a spring to compress the air thus decreasing mechanism size, mechanism wear, mechanism weight. 7. To provide an electric motor driven gun in which the chambering of the projectiles is controlled by the electric motor thereby simplifying the design and increasing efficiency. 8. To provide an electric motor driven gun which uses the heat of compression by reducing the delay between compression and firing, thus, increasing overall efficiency. 9. To provide an electric motor driven gun in which the energy to return the piston uses a spring which is energized on the compression stroke of the piston thus improving efficiency. 10 To provide an electric motor driven gun in which the gear and rack tips are not loaded by the full energy of compression thus significantly reducing gear tip wear.
To provide an electric motor driven gun in which the compressed air release is controlled mechanically thereby simplifying operation, reducing cost and improving reliability.
Further objects and advantages will become more apparent from a consideration of the ensuing detailed description and drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Reference numbers for the drawings are shown below.
FIG. 1 is a side view of the electric powered projectile launcher;
FIG. 2 is a side view showing the rack pinion ready to engage the rack;
FIG. 3 is a side view showing the piston contacting the mechanical valve spool;
FIG. 4 is a side view showing the valve spool in the fully open position;
FIG. 5 is a side view of the rack at the disengagement point to the rack pinion;
FIG. 6 is a side view showing the rack and piston during the return stroke;
FIG. 7 is a top view of the valve in the closed position;
FIG. 8 is a top view of the valve in the open position;
FIG. 9 is a top view of the valve at the tipping point;
FIG. 10 is a side view of the piston with check valve closed;
FIG. 11 is a side view of the piston with ball check valve opened;
FIG. 12 is a control circuit schematic;
FIG. 13 shows the valve operation in relation to the compression piston;
FIG. 14 shows a second embodiment employing a harmonic drive in the start position;
FIG. 15 shows the second embodiment employing a harmonic drive in the middle of the compression stroke;
FIG. 16 shows the second embodiment employing a harmonic drive in the return stroke.
REFERENCE NUMBERS IN DRAWINGS
1 Motor
2 Power Source
3 Control Circuit
4 Rack
5 Piston
6 Bolt
7 Compression Valve
8 Barrel
9 Projectile
10 Start Switch
11 Magnet
12 Sensor
13 Compressed Air Passageway
14 Cylinder
15 Bolt Link
16 Projectile Inlet Port
17 Bumper
19 Bolt Rod
20 Bolt Return Spring
21 Forward Air Chamber
22 Projectile Feeder
23 Lost motion coupling
24 Valve Spool
25 Valve Body
26 Valve Retainer
27 Valve Return Spring
28 Valve Spool Stem
29 Cylinder end cap
30 Bolt Limit Spring
31 Drive Train
32 Piston Return Spring
33 Grip
34 Support Bearing
35 Rack Pinion
36 Crank Link
37 Check Valve
38 Check valve Ball
41 Linear Motion Converter
702 Main Body of Valve Spool
704 Reduced diameter Body of Valve Spool
DETAILED DESCRIPTION OF THE INVENTION
Although the following relates substantially to one embodiment of the design, it will be understood by those familiar with the art that changes to materials, part descriptions and geometries can be made without departing from the spirit of the invention. Additional designs can be created by combining various described elements. These may have particular advantages depending on the design requirements of the particular electric air gun.
In this embodiment, the front end of the piston ( 5 ), the cylinder ( 14 ) and the cylinder end cap ( 29 ) which in the preferred embodiment is a surface of the compression valve ( 7 ) define the volume of the forward air chamber ( 21 ) as shown in FIG. 1 . At its initial state before the cycle starts, the forward air chamber ( 21 ) has a volume that is proportional to the size and weight of the projectile which includes the paintball. For paintball, we typically use a volume in the approximate range of 6 to 9 in 3 at standard temperature and pressure conditions. Although the initial pressure of this starting air can be varied, atmospheric pressure is normally chosen. The piston ( 5 ) moves linearly forward compressing the air in the forward air chamber ( 21 ) while also energizing the piston return spring ( 32 ). The piston return spring ( 32 ) biases the piston ( 5 ) to an initial position and is energized by the motor ( 1 ) during the compression cycle and is not used in compressing the air.
Referring to FIG. 1 , the cycle is initiated by the user pressing a start switch ( 10 ) or trigger that causes power to be directed from the power source ( 2 ) to the motor ( 1 ) through the control circuit ( 3 ). The control circuit ( 3 ) may be any apparatus for connecting and disconnecting power to the motor ( 1 ) to allow a linear air compressor to pressurize air against a valve, cause the valve to open allowing air to flow thru the compressed air passageway ( 13 ) as shown in FIG. 3 past the projectile inlet port ( 16 ) and forcefully ejecting the projectile out of the barrel. The rack ( 4 ) and piston ( 5 ) assembly (referred to as a linear air compressor) is returned to substantially the same start position by the piston return spring ( 32 ). Directing power to the motor ( 1 ) causes it to turn, transferring energy through the rotating elements of the system and into the rack pinion ( 35 ) as shown in FIG. 3 . The rack pinion ( 35 ) rotates as shown in FIG. 3 where the rack pinion ( 35 ) meshes with the teeth in the rack ( 4 ). The rack ( 4 ) preferably has one or more teeth substantially removed behind the initial engagement tooth.
An advantage found was that by removing or cutting down one or more teeth past the initial engagement tooth, the alignment tolerance for engagement between the rack ( 4 ) and the rack pinion ( 35 ) at the start of the cycle is substantially improved. This significantly improves the wear characteristics of the mechanism since it increases the engagement tolerance of the rack pinion to the rack by more then 50% making it far less likely that the initial teeth mesh in an interfering fashion. The motor ( 1 ) continues to rotate transferring energy through the drive train ( 31 ) which is a series of gears forming a reduction apparatus. This in turn rotates the rack pinion ( 35 ). This moves the rack ( 4 ) and the piston ( 5 ) towards the compression valve ( 7 ) compressing the air in the forward air chamber ( 21 ). The air in the forward air chamber is compressed in such a way that the compression exponent is greater then 1. Compression exponents greater then 1 yield higher air pressures then would be expected for a given compression ratio thus making a more efficient design. The simplified formula for compression can be written as: PV n =K. Where P is pressure, V is volume, n is the compression exponent and K is a constant. For air in isothermal compression the exponent is 1, for adiabatic compression it is about 1.4. In an efficient design, the compression cycle is sufficiently short as to yield a compression exponent of approximately at least 1.10. The air in the forward air chamber ( 21 ) is held between the piston ( 5 ) and the cylinder end cap ( 29 ) until the compression valve ( 7 ) opens. By trapping the air in the forward air chamber ( 21 ), the compressed air in the forward air chamber ( 21 ) can be released while the rack pinion still has good engagement to the rack ( 4 ) as clearly shown in FIGS. 3 and 4 . This gives the advantage of allowing a higher contact ratio between the invention's rack pinion ( 35 ) and rack ( 4 ) than has heretofore been seen on an intermittent gear and rack mechanism. Previously, the contact ratio has gone to zero at the point at which the rack ( 4 ) releases from the rack pinion ( 35 ) leading to severe gear tip wear and short life in those commercial mechanisms. Contact ratio as commonly defined in gear technology is the ratio of the length of path of contact of a gear mesh to the base pitch. This higher contact ratio provides the advantage of substantially reducing the wear on the rack ( 4 ) and rack pinion ( 35 ) over other designs and allows the launching of larger more energetic projectiles such as those used in paintball. Once the rack and rack pinion are initially fully engaged, the rack ( 4 ) and rack pinion ( 35 ) maintain a contact ratio of approximately greater then 0.1 until the compression valve ( 7 ) is released.
Further attached to the rack ( 4 ) is a bolt link ( 15 ) which can slide along the bolt rod ( 19 ). As the rack ( 4 ) moves forward it contacts the lost motion coupling ( 23 ) which slides along the bolt rod ( 19 ). As the rack ( 4 ) and piston ( 5 ) continue forward, the bolt link ( 15 ) pushes on the lost motion coupling ( 23 ) to cause it to engage the bolt limit spring ( 30 ). The lost motion coupling ( 23 ) allows the motion of the bolt ( 6 ) to be limited to a fraction of the movement of the piston ( 5 ) thus increasing the efficiency of the design. The movement of the bolt is limited to less then approximately 80% of the movement of the piston.
The bolt limit spring ( 30 ) compresses against the bolt rod ( 19 ) moving the bolt ( 6 ) forward chambering the projectile ( 9 ) and further shutting off the projectile inlet port ( 16 ) as shown in FIG. 4 . The shutoff of the projectile inlet port ( 16 ) by the movement of the bolt ( 6 ) functions to direct the air out the barrel rather then allowing a portion to flow thru the projectile inlet port. This action is sometimes referred to as a valve but is substantially different from the compression valve ( 7 ) which performs another function in the present invention. Additionally, the bolt limit spring ( 30 ) limits the maximum bolt closure force which reduces chance of injury at the pinch point between the bolt ( 6 ) and the projectile inlet port. ( 16 ) Once the projectile has been chambered and the projectile inlet port ( 16 ) has been shut off, the compression valve ( 7 ) is opened.
Two parameters play importantly in the design of the valve ( 7 ): the pressure drop through the compression valve ( 7 ), and the valve opening time. It was originally thought that standard valve designs used in air guns would be suitable for the present design, but upon testing, it was found that they were structurally inefficient and not suitable for an electric air gun. The compression valve ( 7 ) in the preferred embodiment is referred to as a mechanical snap acting valve in which the valve has an opening speed of less then 20 milliseconds from initial cracking to greater then substantially 70% of full flow. One way to meet this requirement is that the actuation or opening force is approximately a minimum of 1.5 times the maintaining force for the valve. The preferred embodiment of the compression valve ( 7 ) is shown in FIGS. 7 , 8 , 9 , 10 and 13 . In FIG. 7 , the compression valve sealing member alternately referred to henceforth as the valve spool ( 24 ) is shown seating up against the valve body ( 25 ). The valve spool ( 24 ) articulates in a direction parallel to the piston and rack. The valve spool ( 24 ) is held in position by two valve retainers ( 26 ) which are positioned in an opposed relationship, and a valve return spring ( 27 ). The composition of the valve retainers ( 26 ) in this embodiment are two cups and two balls but they could be any apparatus which retains the valve spool ( 24 ) or sealing member in the initial sealed state until a threshold pressure or force is applied. The valve spool ( 24 ) includes a main body ( 702 ) and a reduced diameter body ( 704 ). The valve spool ( 24 ) is such that the valve retainers ( 26 ) act on a detent or an inclined portion between the main body ( 702 ) and the reduced diameter body ( 704 ) of the valve spool ( 24 ) in such a fashion that once the valve retainer ( 26 ) moves relative to the surface of the valve spool ( 24 ) past the incline ramp on the valve spool ( 24 ) and is adjacent to the main body ( 702 ) and moves away from the reduced diameter body ( 704 ) ( FIG. 9 ) the maintaining force of the valve spool ( 24 ) is reduced by more then substantially 50%. The restoration force of the valve spool ( 24 ) is provided by the valve return spring ( 27 ). These design features causes the valve spool ( 24 ) to have a tipping point which when exceeded causes the valve spool ( 24 ) to quickly snap open thereby communicating the compressed gas in the air chamber thru the compressed air passageway ( 13 ) and to the projectile causing the projectile ( 9 ) to exit the barrel ( 8 ). The result of such a design is that a standard 68 caliber paintball can be launched at approximately 300 fps when the air in the forward air chamber ( 21 ) is compressed to approximately 160 psi with a volume of approximately 1.2 in 3 . Using other valves which do not open as quickly or as fully caused a drop in velocity of over 70 fps. Since energy is the square term of velocity, those valves required more then 2× the input energy for the same energy output in the projectile. The present design for illustration uses a valve spool ( 24 ) weighing approximately 1 oz, a valve return spring ( 27 ) compressed to approximately 3 lbs and valve retainers ( 26 ) resulting in an opening force of approximately 24 lbs. The face diameter of the valve spool ( 24 ) is approximately 0.437 in. The internal pressure in the forward air chamber reaches approximately 160 psi resulting in a force on the face diameter of the valve of 24 lbs. This moves the valve spool ( 24 ) past the tipping point (a displacement of approximately 0.06 inches) at which the maintaining force drops to 3 lbs. The tipping point is clearly shown in FIG. 9 in which the oring on the valve spool ( 24 ) has not moved past the compressed air passageway ( 13 ) thus leaving the air under compression in the forward air chamber ( 21 ). The oring is an elastomenc element which functions as a sealing member to allow clearance between the valve spool and the valve body. The opening force on the valve spool ( 24 ) is approximately 21 lbs. The additional stroke of the valve spool ( 24 ) to the fully open position shown in FIG. 8 is 0.5 inches. This distance is traversed in less then approximately 5 milliseconds resulting in nearly instantaneous communication of the compressed air in the forward air chamber ( 21 ) thru the compressed air passageway ( 13 ) by the projectile inlet port ( 16 ) and forcing the projectile out the barrel. The above weights, distances and forces are merely for illustrative purposes and not meant to limit the scope of the invention. An advantage of the Cv characteristics and snap action feature of this valve is that the compression energy can be reduced significantly and by more then approximately 30% over standard valves used in bb or paintball guns. The term Cv refers to the flow coefficient of a valve and relates the pressure drop across a valve to the flow thru the valve. A high Cv valve gives a larger flow of thru a valve at a given pressure drop then a low Cv valve. An advantage of our valve design is the combination of high Cv with a very fast opening speed resulting in a very efficient conversion of air energy to projectile energy. A second feature of the valve spool ( 24 ) in the preferred embodiment is a valve stem ( 28 ). Opening of the valve spool ( 24 ) can occur when the pressure in the forward air chamber exceeds the maintaining pressure of the valve retainers ( 26 ) and valve return spring ( 27 ) or preferably when the piston ( 5 ) pushes the valve stem ( 28 ) moving the valve spool ( 24 ) past the tipping point. The contact of the piston ( 5 ) to the valve spool stem ( 28 ) can be seen in FIG. 3 . The valve spool ( 24 ) is shown in the full open position in FIG. 5 at which point the air in the forward air chamber ( 21 ) is in communication with the projectile ( 9 ) and can propel it out the barrel ( 8 ). A further illustration of this is shown in FIG. 13 . The valve stem ( 28 ) allows the piston ( 5 ) to hold the valve open even when the pressure in the forward air chamber drops. This further improves the efficiency of the valve since the valve is held open even as the pressure in the forward air chamber ( 21 ) drops below the pressure required to hold the valve spool ( 24 ) open under the action of the valve return spring ( 27 ). A further advantage of the invention is that the valve spool ( 24 ) can no longer stick in the closed position. If the valve spool ( 24 ) were to stick in the closed position during a cycle and the rack pinion ( 35 ) were to release the rack ( 4 ), the rack and piston assembly would be thrown violently towards the rear of the apparatus potentially causing damage. The piston ( 5 ) and rack ( 4 ) continue to move in the forward direction until the cutaway teeth on the rack pinion ( 35 ) are opposite the rack ( 4 ). The rack and pinion are now returned to the initial position via a mechanical storage element such as the piston return spring ( 32 ). The piston return spring ( 32 ) does not play a direct part in the compression of the air and is sized such that its total energy is less then approximately 25% of the energy required to propel the projectile. In this particular design, the total return energy in the spring is approximately 1.5 ft lbs. In the return process, makeup air should be allowed to rapidly enter the forward air chamber. Although any valve could be used for this purpose, it is preferred to use a mechanical check valve ( 37 ) contained within the piston ( 5 ) as shown in FIG. 11 . On return of the piston ( 5 ) and rack ( 4 ), air pushes the check valve ball ( 38 ) away from the sealed position and flows thru the check valve ( 37 ) replenishing the forward air chamber ( 21 ). The piston return spring ( 32 ) is preferentially a constant force spring located external to the air cylinder. Constant force springs are particularly suited to this invention because of the characteristics of long stroke, light weight and constant force. The constant force in the fully retracted position provides more stability and better position control of the rack ( 4 ) in its initial starting position. Although constant force springs are advantageous, the piston return spring ( 32 ) could be any elastic element which is energized during the compression stroke of the piston. The excess energy from the return of the piston ( 5 ) and rack ( 4 ) are absorbed by the bumper ( 17 ). The bumper ( 17 ) only need absorbs the small amount of kinetic energy caused by the return of the rack ( 4 ) and piston ( 5 ) assembly and is preferably made from an elastomer. The valve spool ( 24 ) is now free to return to the closed position via the valve return spring ( 27 ). Solenoid valves can be used as alternatives to the mechanical valve. The release of the rack pinion ( 35 ) from the rack ( 4 ) is preferably detected using a sensor ( 12 ) which causes the control circuit ( 3 ) as shown in FIG. 12 to turn off the motor power and brake the system. The return of the rack ( 4 ) to its initial position is preferably detected using an additional sensor ( 12 ) and marks the completion of a cycle. An additional feature of this embodiment is to limit the number of teeth in the rack ( 4 ) behind the initial engagement point. This makes it impossible for the piston to bottom out against the cylinder end cap ( 29 ) in the compression and firing cycle. This embodiment therefore has an advantage by eliminating the double recoil limitation of existing designs.
The interrupted rack pinion ( 35 ) and rack ( 4 ) together form a linear motion converter which converts the rotational motion of the motor to the linear motion of the rack. Alternative embodiments to the rack ( 4 ) and rack pinion ( 35 ) include a slider crank, eccentric or cam drive which power the piston ( 5 ) in a lineal direction to compress air in the forward air chamber ( 21 ) against the cylinder end cap ( 29 ) and compression valve ( 7 ). These alternative embodiments have useful advantages including the elimination of engagement and disengagement as well as elimination of the piston return spring ( 32 ). This embodiment would provide for a positive return of the piston ( 7 ) to an initial position thus potentially simplifying the apparatus and improving its reliability. FIG. 14 shows one possible implementation of such an embodiment. In this figure, the piston ( 5 ) is shown at a starting position of approximately +/−60 degrees around bottom dead center. The linear motion converter ( 41 ) in this case is a slider crank and rotates in cooperation with the motor and gear reduction apparatus to push the piston ( 5 ) and compressing the air in the forward air chamber ( 21 ) against compression valve ( 7 ) as shown in FIG. 15 . The operation of the valve is similar as which has been heretofore described and releases the compressed air to launch the projectile. The return of the piston ( 5 ) and replenishment of air in forward air chamber ( 21 ) is shown in FIG. 16 . The control circuit and appropriately placed sensors could easily allow for a consistent start and stop cycle. Although the reduction apparatus in these embodiments is shown as a spur and worm gear drive, other reduction apparatus such as pulleys, belts, chains and planetary drives, could be used without departing from the spirit of the invention.
Circuit Operation:
A schematic of the preferred control circuit ( 3 ) is shown in FIG. 12 . In the preferred embodiment, the control circuit ( 3 ) includes a microprocessor, high power switching elements and three control circuit inputs. An interface can display faults. The control circuit ( 3 ) can input signals from timers and/or sensors. Looking additionally to FIG. 1 , this embodiment uses a start switch ( 10 ) and either a sensor or another suitable apparatus to inhibit the start switch to ensure that the compression piston ( 5 ) is in the initial position. This embodiment employs a hall sensor ( 12 ) and a magnet which moves cooperatively with the rack ( 4 ) and piston ( 5 ) assembly. Additionally, a method and apparatus of determining motor speed using FETs or relays to control the power to the motor ( 1 ) are advantageous. Motor speed sensing is useful in determining and responding to a fault condition. Speed sensing means could include voltage or current sensing on the motor or a rotational sensor located within the drive train ( 31 ). In order to maintain responsiveness of an electric air gun, it is desirable that the overall resistance from the power source ( 2 ) to the motor ( 1 ) be kept very low. A second sensor ( 12 ) is used to determine the decoupling of the rack ( 4 ) from the rack pinion ( 35 ). In this embodiment, a magnet is attached to the rack pinion ( 35 ) and a hall sensor is used to determine when the rack pinion ( 35 ) disengages from the rack. Once the rack pinion ( 35 ) has disconnected from the rack ( 4 ), power can be removed from the motor and the motor can be braked dynamically. This brings it to a quick stop and prevents over rotation of the rack pinion ( 35 ) where it could possibly jamb into the returning rack ( 4 ) before it has fully returned to its initial position.
An additional advantage of the present embodiment over prior designs is afforded by the use of the sensors ( 12 ). Using these sensors, it is possible to maximize the firing rate of the device by monitoring the start switch ( 10 ) after a cycle is initiated. One such technique is to monitor and store an additional actuation of the start switch ( 10 ) while the apparatus is in operation. The stored actuation is used in cooperation with a timer which begins a countdown when the additional start switch ( 10 ) actuation is recorded. The timer is set to correspond to a delay of less then 200 milliseconds and preferably 100 milliseconds. The stored actuation can automatically initiate a followup cycle if the sensor ( 12 ) detects that the rack ( 4 ) is back in the initial position before the timer setpoint is exceeded. This permits a more seamless operation of the apparatus and increases the firing rate since the initiation of a cycle does not have to be timed to the completion of the prior cycle. We call this feature shot storage.
Although the aforementioned elements are used in the preferred design, it is understood by those familiar with the art that considerable simplification is possible without departing from the spirit of the invention. It is further understood by those skilled in the art that the sensors can be used in conjunction with other circuit elements to allow location at different places and that sensors can be of many forms including but not limited to limit switches, hall effect sensors, photosensors, reed switches and current or voltage sensors without departing from the spirit of the invention.
Further preferred circuit embodiments include: low battery indicators, pulse control of motor power, communication ports, status or error displays, lock out on fault conditions, password or keyswitch requirements for operation. Additionally, the circuit could allow for various firing modes such as burst mode for example.
Thus, although there have been described particular embodiments of the present invention of a new and useful PORTABLE ELECTRIC-DRIVEN COMPRESSED AIR PROJECTILE LAUNCHER, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims. | A portable motor driven air gun powered by a power source includes a motor that is coupled to a linear motion converter which drives a piston. The piston compresses air in a chamber against a forward air compression valve producing high-pressure air. When sufficient energy is stored within the air stream by the piston, the compression valve opens which releases the compressed air to push a projectile through a barrel. The engagement and disengagement of the linear motion converter and the connected piston to the motor can be controlled using sensors. The linear motion converter further is coupled to a bolt thru a lost motion device to facilitate positioning of the projectile for firing. The direction speed and operative modes of the gun may be controlled with an electric circuit. The power source is preferably rechargeable, allowing the air gun to be operated independent from either a wall outlet or a compressed air supply. | 5 |
FIELD OF THE INVENTION
[0001] The present invention is generally directed to novel crystalline forms of the acetate salt of (1S,3S,4R)-4-((3aS,4R,5S,7aS)-4-(aminomethyl)-7a-methyl-1-methyleneoctahydro-1H-inden-5-yl)-3-(hydroxymethyl)-4-methylcyclohexanol, processes for their preparation, and pharmaceutical compositions containing them.
BACKGROUND OF THE INVENTION
[0002] Dysregulated activation of the PI3K pathway contributes to inflammatory/immune disorders and cancer. Efforts have been made to develop modulators of PI3K as well as downstream kinases (Workman et al., Nat. Biotechnol 24, 794-796, 2006; Simon, Cell 125, 647-649, 2006; Hennessy et al., Nat Rev Drug Discov 4, 988-1004, 2005; Knight et al., Cell 125, 733-747, 2006; Ong et al., Blood (2007), Vol. 110, No. 6, pp 1942-1949). A number of promising new PI3K isoform specific inhibitors with minimal toxicities have recently been developed and used in mouse models of inflammatory disease (Camps et al., Nat Med 11, 936-943, 2005; Barber et al., Nat Med 11, 933-935, 2005) and glioma (Fan et al., Cancer Cell 9, 341-349, 2006). However, because of the dynamic interplay between phosphatases and kinases in regulating biological processes, inositol phosphatase activators represent a complementary, alternative approach to reduce PIP 3 levels. Of the phosphoinositol phosphatases that degrade PIP 3 , SHIP1 is a particularly ideal target for development of therapeutics for treating immune and hemopoietic disorders because of its hematopietic-restricted expression (Hazen et al., Blood 113, 2924-2933, 2009; Rohrschneider et al., Genes Dev. 14, 505-520, 2000).
[0003] Small molecule SHIP1 modulators have been disclosed, including sesquiterpene compounds such as pelorol. Pelorol is a natural product isolated from the tropical marine sponge Dactylospongia elegans (Kwak et al., J Nat Prod 63, 1153-1156, 2000; Goclik et al., J Nat Prod 63, 1150-1152, 2000). Other reported SHIP1 modulators include the compounds set forth in PCT Published Patent Applications Nos. WO 2003/033517, WO 2004/035601, WO 2004/092100, WO 2007/147251, WO 2007/147252, WO 2011/069118, WO 2014/143561 and WO 2014/158654 and in U.S. Pat. Nos. 7,601,874 and 7,999,010.
[0004] While significant strides have been made in this field, there remains a need for effective small molecule SHIP1 modulators.
[0005] One such molecule is the acetate salt of (1 S,3S,4R)-4-((3aS,4R,5S,7aS)-4-(aminomethyl)-7a-methyl-1-methyleneoctahydro-1H-inden-5-yl)-3-(hydroxymethyl)-4-methylcyclohexanol (referred to herein as Compound 1). Compound 1 is a compound with anti-inflammatory activity and is described in U.S. Pat. Nos. 7,601,874 and 7,999,010, the relevant disclosures of which are incorporated in full by reference in their entirety, particularly with respect to the preparation of Compound 1, pharmaceutical compositions comprising Compound 1 and methods of using Compound 1.
[0006] Compound 1 has the molecular formula, C 20 H 36 NO 2 + .C 2 H 3 O 2 − , a molecular weight of 381.5 g/mole and has the following structural formula:
[0000]
[0007] Compound 1 is useful in treating disorders and conditions that benefit from SHIP1 modulation, such as cancers, inflammatory disorders and conditions and immune disorders and conditions. Compound 1 is also useful in the preparation of a medicament for the treatment of such disorders and conditions.
SUMMARY OF THE INVENTION
[0008] The present invention is generally directed to novel crystalline forms of Compound 1, processes for their preparation, pharmaceutical compositions containing them and methods of using the novel crystalline forms and their compositions.
[0009] Accordingly, in one aspect, this invention is directed to a first novel crystalline form of Compound 1, referred to herein as Compound 1 Form A.
[0010] In another aspect, this invention is directed to a second novel crystalline form of Compound 1, referred to herein as Compound 1 Form B.
[0011] In another aspect, this invention is directed to compositions comprising a pharmaceutically acceptable excipient, carrier and/or diluent and Compound 1 Form A.
[0012] In another aspect, this invention is directed to compositions comprising a pharmaceutically acceptable excipient, carrier and/or diluent and Compound 1 Form B.
[0013] In another aspect, this invention is directed to a method for modulating SHIP1 activity in a mammal comprising administering an effective amount of Compound 1 Form A or an effective amount of a composition comprising Compound 1 Form A to the mammal in need thereof.
[0014] In another aspect, this invention is directed to a method for modulating SHIP1 activity in a mammal comprising administering an effective amount of Compound 1 Form B or an effective amount of a composition comprising Compound 1 Form B to the mammal in need thereof.
[0015] In another aspect, this invention is directed to a method for treating a disease, disorder or condition associated with SHIP1 activity in a mammal comprising administering an effective amount of Compound 1 Form A or an effective amount of a composition comprising Compound 1 Form A to the mammal in need thereof.
[0016] In another aspect, this invention is directed to a method for treating a disease, disorder or condition associated with SHIP1 activity in a mammal comprising administering an effective amount of Compound 1 Form B or an effective amount of a composition comprising Compound 1 Form B to the mammal in need thereof.
[0017] In another aspect, this invention is directed to methods for the preparation of Compound 1 Form A.
[0018] In another aspect, this invention is directed to methods for the preparation of Compound 1 Form B.
[0019] These aspects, and embodiments thereof, are described in more detail below. To this end, various references are set forth herein which describe in more detail certain background information, procedures, compounds and/or compositions, and are each hereby incorporated by reference in their entirety.
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 illustrates the X-Ray Powder Diffraction pattern of amorphous Compound 1.
[0021] FIG. 2 illustrates the X-Ray Powder Diffraction pattern of Compound 1 Form A.
[0022] FIG. 3 illustrates the DSC thermogram of Compound 1 Form A.
[0023] FIG. 4 illustrates the TGA thermogram of Compound 1 Form A.
[0024] FIG. 5 illustrates the molecular structure of Compound 1 Form A, as determined from single crystal data.
[0025] FIG. 6 illustrates the comparison between the simulated powder diffraction pattern and the experimentally derived powder diffraction pattern of Compound 1 Form A.
[0026] FIG. 7 illustrates the crystal packing and hydrogen bond scheme for of Compound 1 Form A.
[0027] FIG. 8A illustrates the full FT-IR spectrum of Compound 1 Form A, FIG. 8B illustrates the expansion of the full FT-IR spectrum of FIG. 8A , in the fingerprint region of 2000 to 750 cm −1 .
[0028] FIG. 9A illustrates the Raman spectrum of Compound 1 Form A, FIGS. 9B and 9C illustrate expansions of the full Raman spectrum of FIG. 9A , in the ranges of ˜3200 to ˜2450 and ˜1900 to ˜200 cm −1 respectively.
[0029] FIG. 10 illustrates the X-Ray Powder Diffraction pattern of Compound 1 Form B.
[0030] FIG. 11 illustrates the DSC thermogram of Compound 1 Form B.
[0031] FIG. 12 illustrates the TGA thermogram of Compound 1 Form B.
[0032] FIG. 13 illustrates the TGA/MS analysis of Compound 1 Form B.
DETAILED DESCRIPTION OF THE INVENTION
[0033] As mentioned above, the present invention is generally directed to novel crystalline forms of Compound 1, processes for their preparation, pharmaceutical compositions containing them and methods of using the novel crystalline forms.
[0034] In general, most pharmaceutical compounds, i.e., those compounds which are useful as pharmaceutical agents, are initially produced in amorphous forms which can be characterized by only short range ordering. These compounds may be challenging to develop, as the amorphous form is often unstable relative to a crystalline form and may convert under certain conditions to any crystalline form, not necessarily the most stable one. In an embodiment of the invention, molecules of Compound 1 in the crystalline form have both short and long range ordering and have different physical properties as compared to the amorphous form.
[0035] Solid state physical properties of a material affect the ease with which the material is handled during processing into a pharmaceutical product, such as a tablet or capsule formulation. The physical properties affect the types of excipients, for example, to be added to a formulation for a pharmaceutical compound. Furthermore, the solid state physical property of a pharmaceutical compound is important to its dissolution in aqueous and liquid milieus, including gastric juices, thereby having therapeutic consequences. The solid state form of a pharmaceutical compound may also affect its storage requirements. From a physicochemical perspective, the crystalline form of a pharmaceutical compound is the preferred form. Organization of the molecules in an ordered fashion to form a crystal lattice provides improved chemical stability, flowability, and other powder properties including reduced moisture sorption. All of these properties are of importance to the manufacturing, formulation, storage and overall manageability of a pharmaceutical drug product.
[0036] Thus, practical physical characteristics are influenced by the particular solid form of a substance. One solid form may give rise to different thermal behavior from that of the amorphous material or other solid forms. Thermal behavior is measured in the laboratory by such techniques as capillary melting point, thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC) and can be used to distinguish some polymorphic solid forms from others. A particular polymorphic solid form may also give rise to distinct physical properties that may be detectable by X-ray powder diffraction (XRPD), solid state 13 C-Nuclear Magnetic Resonance spectroscopy, and infrared or Raman spectrometry.
[0037] Compound 1 exists in an amorphous form, referred to herein as amorphous Compound 1. This invention is therefore directed to stable crystalline forms of Compound 1, i.e., Compound 1 Form A and Compound 1 Form B, whose properties can be influenced by controlling the conditions under which Compound 1 is obtained in solid form. The characteristics and properties of Compound 1 Form A and Compound 1 Form B are each described detail below.
ABBREVIATIONS
[0038] The following abbreviations may be used herein as needed:
[0000] DAD for diode array detector;
DSC for Differential scanning calorimetry;
FT-IR for Fourier transform Infrared Spectroscopy
FWHM for Full Width at Half Maximum;
HPLC for High Performance Liquid Chromatography;
[0039] m.p. for melting point;
PTFE for polytetrafluoroethylene;
rpm for revolutions per minute;
SDTA for Simultaneous differential thermal analysis;
TFA for trifluoroacetic acid;
TGA for Thermogravimetric analysis;
TGA/MS for Thermogravimetric analysis coupled with Mass Spectroscopy; and
XRPD for X-ray powder diffraction.
Compound 1 Form A
[0040] In one embodiment of the invention, Compound 1 Form A is provided, characterized by the selection of one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, twenty-one, twenty-two, twenty-three, twenty-four, twenty-five, twenty-six, or twenty-seven X-ray powder diffraction peaks selected from the group consisting of 6.0, 8.9, 10.7, 11.9, 13.3, 14.9, 15.8, 17.9, 18.4, 18.9, 19.9, 20.1, 20.3, 21.6, 23.6, 24.0, 24.5, 24.8, 25.3, 25.5, 25.8, 26.1, 26.9, 27.0, 27.2, 27.7, 27.9 degrees 2θ±0.3 degrees 2Θ, more preferably ±0.2 degrees 2Θ, even more preferably ±0.1 degrees 2Θ, most preferably ±0.05 degrees 2Θ.
[0041] In another embodiment, Compound 1 Form A is characterized by the following set of XRPD peaks and, optionally, by the associated intensities listed in Table 1:
[0000]
TABLE 1
XRPD PEAK TABLE FOR COMPOUND 1 FORM A
Embodiment
Preferred embodiment
Peak
Angle
d-
Angle
d-
ID
(2⊖)
Value
Intensity*
(2⊖)
Value
Intensity*
1
6.0
14.8
L
5.9719
14.7875
L
2
8.9
9.9
H
8.9297
9.8950
H
3
10.7
8.2
M
10.7454
8.2267
M
4
11.9
7.4
M
11.9490
7.4006
M
5
13.3
6.6
M
13.3350
6.6344
M
6
14.9
5.9
L
14.9310
5.9286
L
7
15.8
5.6
H
15.8040
5.6030
H
8
17.9
5.0
M
17.8991
4.9516
M
9
18.4
4.8
L
18.4005
4.8178
L
10
18.9
4.7
L
18.8893
4.6942
L
11
19.9
4.5
M
19.8539
4.4683
M
12
20.1
4.4
M
20.0844
4.4175
M
13
20.3
4.4
H
20.2699
4.3775
H
14
21.6
4.1
L
21.5792
4.1148
L
15
23.6
3.8
L
23.6037
3.7662
L
16
24.0
3.7
L
24.0130
3.7030
L
17
24.5
3.6
L
24.5354
3.6253
L
18
24.8
3.6
L
24.7525
3.5940
L
19
25.3
3.5
L
25.2688
3.5217
L
20
25.5
3.5
L
25.4612
3.4955
L
21
25.8
3.5
L
25.7788
3.4532
L
22
26.1
3.4
L
26.1404
3.4062
L
23
26.9
3.3
L
26.8526
3.3175
L
24
27.0
3.3
L
26.9880
3.3011
L
25
27.2
3.3
L
27.1630
3.2803
L
26
27.7
3.2
L
27.6680
3.2215
L
27
27.9
3.2
L
27.8793
3.1976
L
*For normalized intensity values: L = 3-25, M = 25-60, H = 60-100.
[0042] In another embodiment, Compound 1 Form A is characterized by an XRPD substantially according to FIG. 2 .
[0043] In a preferred embodiment, Compound 1 Form A is characterized by an XRPD containing at least one of the following peaks: 5.96, 8.92, 10.74, 13.33 and 15.80 degrees 2Θ±0.3 degrees 2Θ, more preferably ±0.2 degrees 2Θ, even more preferably ±0.1 degrees 2Θ, most preferably ±0.05 degrees 2Θ. In a more preferred embodiment, Compound 1 Form A is characterized by an XRPD containing at least two of the following peaks: 5.96, 8.92, 10.74, 13.33 and 15.80 degrees 2Θ±0.3 degrees 2Θ, more preferably ±0.2 degrees 2Θ, even more preferably ±0.1 degrees 2Θ, most preferably ±0.05 degrees 2Θ.
[0044] In another embodiment, Compound 1 Form A is characterized by a DSC thermogram substantially according to FIG. 3 .
[0045] In another embodiment, Compound 1 Form A is characterized by a TGA thermogram substantially according to FIG. 4 .
[0046] In another embodiment, Compound 1 Form A is characterized by a DSC thermogram with an endothermic event with an onset at 173.1° C.±0.3° C., more preferably ±0.2° C., most preferably ±0.1° C., and a characterizing endothermic peak at 188.2° C.±0.3° C., more preferably ±0.2° C., most preferably ±0.1° C., followed by a second endothermic event with an onset at 187.1° C.±0.3° C., more preferably ±0.2° C., most preferably ±0.1° C., and a characterizing peak at 192.5° C.±0.3° C., more preferably ±0.2° C., most preferably ±0.1° C. From the analysis of the DSC thermogram, it was concluded that Compound 1 Form A is anhydrous.
[0047] In another embodiment, Compound 1 Form A is anhydrous and is stable as indicated by the DSC thermogram in FIG. 3 , which shows the acetate is closely associated with Compound 1 and only decomposes at or near the melting point. Compound 1 Form A crystallizes in a chiral monoclinic C2 space group with one anion-cation pair in the asymmetric unit, as seen in FIG. 7 . The crystal is held together by a network of intermolecular hydrogen bonds and a Zig-Zag chain is formed, which likely provides the unexpected high stability/melting point of Compound 1.
[0048] In another embodiment of the invention, Compound 1 Form A is provided, characterized by the selection of one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, twenty-one, twenty-two, twenty-three, twenty-four, twenty-five, twenty-six, twenty-seven, twenty-eight, twenty-nine, thirty, thirty-one, thirty-two, thirty-three, thirty-four or thirty-five FT-IR transmission peaks selected from the group consisting of 655.0, 668.5, 675.2, 685.4, 774.2, 805.4, 814.4, 824.2, 880.2, 910.3, 937.4, 963.3, 1006.4, 1044.1, 1077.9, 1101.4, 1169.3, 1195.3, 1222.4, 1299.7, 1332.8, 1386.5, 1397.7, 1436.3, 1446.9, 1477.1, 1494.8, 1520.2, 1557.0, 1612.9, 1653.4, 2853.6, 2931.3, 2964.8, 3335.2±3 cm −1 , more preferably ±2 cm −1 , and most preferably ±1 cm −1 .
[0049] In another embodiment, Compound 1 Form A is characterized by the following set of FT-IR transmission peaks listed in Table 1:
[0000]
TABLE 2
FT-IR TRANSMISSION PEAK TABLE
FOR COMPOUND 1 FORM A
Peak ID
FT-IR transmission (cm −1 )
1
655.0
2
668.5
3
675.2
4
685.4
5
774.2
6
805.4
7
814.4
8
824.2
9
880.2
10
910.3
11
937.4
12
963.3
13
1006.4
14
1044.1
15
1077.9
16
1101.4
17
1169.3
18
1195.3
19
1222.4
20
1299.7
21
1332.8
22
1386.5
23
1397.7
24
1436.3
25
1446.9
26
1477.1
27
1494.8
28
1520.2
29
1557.0
30
1612.9
31
1653.4
32
2853.6
33
2931.3
34
2964.8
35
3335.2
[0050] In another embodiment, Compound 1 Form A is characterized by an FT-IR transmission spectrum substantially according to FIG. 8 .
[0051] In a preferred embodiment, Compound 1 Form A is characterized by an FT-IR transmission spectrum containing at least one of the following peaks: 910, 1006, 1169 and 1398 cm −1 ±3 cm −1 , more preferably ±2 cm −1 , and most preferably ±1 cm −1 . In a more preferred embodiment, Compound 1 Form A is characterized by an FT-IR transmission spectrum containing at least two of the following peaks: 910, 1006, 1169 and 1398 cm −1 ±3 cm −1 , more preferably ±2 cm −1 , and most preferably ±1 cm −1 .
[0052] In another embodiment of the invention, Compound 1 Form A is provided, characterized by the selection of one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, or eighteen Raman shift peaks selected from the group consisting of 2991.2, 2977.3, 2935.3, 2925.8, 2903.7, 2858.3, 1654.3, 1477.9, 1447.7, 1307.9, 1009.8, 945.8, 919.2, 881.7, 743.7, 721.8, 614.8, 423.6±3 cm −1 , more preferably ±2 cm −1 , and most preferably ±1 cm −1 .
[0053] In another embodiment, Compound 1 Form A is characterized by the following set of Raman shift peaks listed in Table 1:
[0000]
TABLE 3
RAMAN SHIFT PEAK TABLE FOR COMPOUND 1 FORM A
Peak ID
Raman Shift (cm −1 )
1
2991.2
2
2977.3
3
2935.3
4
2925.8
5
2903.7
6
2858.3
7
1654.3
8
1477.9
9
1447.7
10
1307.9
11
1009.8
12
945.8
13
919.2
14
881.7
15
743.7
16
721.8
17
614.8
18
423.6
[0054] In another embodiment, Compound 1 Form A is characterized by a Raman shift spectrum substantially according to FIG. 9 .
[0055] In a preferred embodiment, Compound 1 Form A is characterized by a Raman shift spectrum containing at least one of the following peaks: 1654, 1478, 919, 744, 722, and 615 cm −1 ±3 cm −1 , more preferably ±2 cm −1 , and most preferably ±1 cm −1 . In a more preferred embodiment, Compound 1 Form A is characterized by a Raman shift spectrum containing at least two of the following peaks: 1654, 1478, 919, 744, 722, and 615 cm −1 ±3 cm −1 , more preferably ±2 cm −1 , and most preferably ±1 cm −1 .
[0056] In another embodiment, Compound 1 Form A, which is anhydrous, is stable and resistant to hydrate formation, to significant amounts of exposure to water as it can be handled in the presence of water (see Example 8 below; 40% water) and exposed to high humidity (75% relative humidity) for 2 days (see General Method J below) without converting to another form, as evidenced by XRPD data (see Example 3 below).
[0057] In another embodiment, Compound 1 Form A is in a substantially pure form, and preferably substantially free from other amorphous, crystalline and/or polymorphic forms. In this respect, “substantially pure” means at least about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the pure compound. In this respect, “substantially free from other amorphous, crystalline and/or polymorphic forms” means that no more than about 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1% of these other amorphous, crystalline and/or polymorphic forms are present.
[0058] In embodiments of the invention, a method for the preparation of Compound 1 Form A is provided, including the steps of preparing a suspension of amorphous Compound 1 in a solvent selected from the group consisting of water, methanol, ethanol, isopropanol, acetone, 2-butanone, ethyl acetate, 1,4-dioxane, tert-butyl methyl ether, tetrahydrofuran, acetonitrile, chloroform, cyclohexane, heptane, toluene, p-xylene, cumene, isopropyl acetate, isopropyl ether, dichloromethane, 2-methoxyethanol, ethyl formate, anisole, 1,2-dimethoxyethane, 2-methyltetrahydrofuran, N,N-dimethylacetamide, 1-butanol, 2-ethoxyethanol, butyl acetate, methyl formate, n-pentane, N,N-dimethylformamide, hexane, 2,2,4-trimethylpentane, diethyl ether, cyclopentane, decane or a mixture thereof, and crystallizing Compound 1 Form A by methods known to those skilled in the art, such as, but not limited to, cooling crystallization, evaporative crystallization by anti-solvent addition, vapor diffusion into liquid crystallization, vapor diffusion onto a solid crystallization, and crystallization by wet milling. In a preferred embodiment, the solvent is selected from the group of water, acetonitrile, methanol, 2-butanone, ethanol, isopropanol, acetone, ethyl acetate, tert-butyl methyl ether, heptane, isopropyl acetate, isopropyl ether, ethyl formate, anisole, 2-methyltetrahydrofuran, 1-butanol, butyl acetate, methyl formate, n-pentane, 2,2,4-trimethylpentane, diethyl ether, decane, or a mixture thereof. In a more preferred embodiment, the solvent is selected from the group of water, acetonitrile, methanol, 2-butanone, ethanol, isopropanol, acetone, ethyl acetate, tert-butyl methyl ether, heptane, isopropyl acetate, ethyl formate, anisole, 1-butanol, butyl acetate, n-pentane, diethyl ether, isopropyl ether, 2-methyltetrahydrofuran, methyl formate, 2,2,4-trimethylpentane, cyclopentane, decane or a mixture thereof.
[0059] In certain embodiments, a second solvent (co-solvent or anti-solvent) is used in an amount between 5% and 75% (v/v) with an amount of first solvent between 95% and 25% (v/v), preferably between 10% and 35% (v/v) with an amount of first solvent between 90% and 65% (v/v), more preferably between 15% and 30% (v/v) with an amount of first solvent between 85% and 70% (v/v), and most preferably between 20% and 25% (v/v), with an amount of first solvent between 80% and 75% (v/v). In a preferred embodiment, acetonitrile, heptane, toluene, p-xylene, methylcyclohexane, chloroform, anisole, isopropyl acetate, cyclohexane, or n-pentane is used as a second solvent.
[0060] The crystal of Compound 1 Form A of the invention has also been characterized in one aspect relating to the single-crystal structure of Compound 1 Form A as depicted in FIG. 5 and/or FIG. 7 and/or in Table 4:
[0000]
TABLE 4
CRYSTAL DATA AND STRUCTURE
REFINEMENT FOR 1 FORM A.
Empirical formula
C 20 H 36 NO 2 + •C 2 H 3 O 2 −
Formula weight
381.54
Temperature (K)
200(2)
Wavelength (Å)
0.71073
Crystal system
Monoclinic
Space group
C2
Unit cell dimensions (Å)
a [Å]
19.8179(7)
b [Å]
7.2587(3)
c [Å]
17.8349(6)
β [°]
123.813(3)
Volume (Å 3 )
2131.64(14)
Z
4
Density (calculated, g/cm 3 )
1.189
μ (mm −1 )
0.080
F(000)
840
Crystal size (mm)
1 × 0.5 × 0.5
Θ range for data collection (°)
2.5 → 25
Reflections collected
7037
Independent reflections
3493 [R int = 0.0493]
Completeness to Θ max (%)
99.2
Absorption correction
semi-empirical from equivalents
Max. and min. transmission
0.9611 and 0.4938
Data/restraints/parameters
3493/1/265
Goodness-of-fit on F 2
1.034
Final R indices [I > 2sigma(I)]
R1 = 0.0484, wR2 = 0.1202
R indices (all data)
R1 = 0.0598, wR2 = 0.1291
Largest diff. peak and hole (e/Å 3)
0.243 and −0.202
Compound 1 Form B
[0061] In another embodiment of the invention, there is disclosed crystalline Compound 1 Form B, characterized by the selection of one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, twenty-one, twenty-two, twenty-three, twenty-four, twenty-five, twenty-six, twenty-seven, twenty-eight, twenty-nine, thirty, or thirty-one X-ray powder diffraction peaks selected from the group consisting of 5.5, 9.0, 9.4, 10.5, 12.2, 12.9, 13.2, 14.0, 14.3, 15.4, 16.1, 16.6, 17.0, 18.0, 18.3, 19.0, 20.0, 21.3, 22.8, 24.4, 25.0, 25.8, 26.8, 27.3, 28.1, 28.9, 31.1, 32.5, 33.6, 34.3, 36.2 degrees 2Θ±0.3 degrees 2Θ, more preferably ±0.2 degrees 2Θ, even more preferably ±0.1 degrees 2Θ, most preferably ±0.05 degrees 2Θ.
[0062] In another embodiment, Compound 1 Form B can be characterized by the following set of XRPD peaks and, optionally, by the associated intensities listed in Table 5:
[0000]
TABLE 5
XRPD PEAK TABLE FOR COMPOUND 1 FORM B
Embodiment
Preferred embodiment
Peak
Angle
d-
Angle
d-
ID
(2⊖)
Value
Intensity*
(2⊖)
Value
Intensity*
1
5.5
16.0
M
5.5056
16.0389
M
2
9.0
9.8
M
8.9784
9.8414
M
3
9.4
9.4
L
9.3738
9.4272
L
4
10.5
8.4
L
10.4954
8.4221
L
5
12.2
7.2
M
12.2283
7.2322
M
6
12.9
6.8
H
12.9263
6.8432
H
7
13.2
6.7
H
13.1691
6.7176
H
8
14.0
6.3
L
14.0469
6.2997
L
9
14.3
6.2
L
14.2556
6.2079
L
10
15.4
5.8
M
15.3571
5.7651
M
11
16.1
5.5
L
16.1173
5.4948
L
12
16.6
5.3
L
16.5638
5.3477
L
13
17.0
5.2
L
17.0462
5.1974
L
14
18.0
4.9
H
18.0374
4.9140
H
15
18.3
4.8
M
18.3289
4.8365
M
16
19.0
4.7
H
18.9616
4.6765
H
17
20.0
4.4
H
19.9729
4.4419
H
18
21.3
4.2
M
21.2924
4.1696
M
19
22.8
3.9
L
22.8307
3.8920
L
20
24.4
3.7
L
24.3507
3.6524
L
21
25.0
3.6
L
24.9971
3.5594
L
22
25.8
3.4
L
25.8342
3.4459
L
23
26.8
3.3
L
26.7691
3.3276
L
24
27.3
3.3
L
27.2716
3.2675
L
25
28.1
3.2
L
28.0939
3.1737
L
26
28.9
3.1
L
28.8820
3.0888
L
27
31.1
2.9
L
31.0503
2.8779
L
28
32.5
2.8
L
32.4944
2.7532
L
29
33.6
2.7
L
33.5513
2.6689
L
30
34.3
2.6
L
34.2825
2.6136
L
31
36.2
2.5
L
36.2378
2.4756
L
*For normalized intensity values: L = 3-25, M = 25-60, H = 60-100.
[0063] In another embodiment, Compound 1 Form B is characterized by an XRPD substantially according to FIG. 10 .
[0064] In a preferred embodiment, Compound 1 Form B is characterized by an XRPD pattern containing at least one of the following peaks: 5.5056, 9.3738 and 12.2283 degrees 2Θ±0.3 degrees 2Θ, more preferably ±0.2 degrees 2Θ, even more preferably ±0.1 degrees 2Θ, most preferably ±0.05 degrees 2Θ. In a more preferred embodiment, Compound 1 Form B is characterized by an XRPD containing at least two of the following peaks: 5.5056, 9.3738 and 12.2283 degrees 2Θ±0.3 degrees 2Θ, more preferably ±0.2 degrees 2Θ, even more preferably ±0.1 degrees 2Θ, most preferably ±0.05 degrees 2Θ.
[0065] In another embodiment, Compound 1 Form B is characterized by a DSC substantially according to FIG. 11 .
[0066] In another embodiment, Compound 1 Form B is characterized by a TGA substantially according to FIG. 12 .
[0067] In another embodiment, Compound 1 Form B of the present invention is characterized by DSC with an endothermic event with an onset at 170.4° C.±0.3° C., more preferably ±0.2° C., most preferably ±0.1° C. and a characterizing endothermic peak at 186.6° C.±0.3° C., more preferably ±0.2° C., most preferably ±0.1° C. From thermal analysis, it is concluded that solid Compound 1 Form B is a hydrate.
[0068] In another embodiment, Compound 1 Form B is a hydrate.
[0069] In another embodiment, Compound 1 Form B is in a substantially pure form, preferably substantially free from other amorphous, crystalline and/or polymorphic forms. In this respect, “substantially pure” relates to at least about 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% of the pure compound. In this respect, “substantially free from other amorphous, crystalline and/or polymorphic forms” means that no more than about 20% 15%, 10%, 5%, 4%, 3%, 2%, 1% of these other amorphous, crystalline and/or polymorphic forms are present in the form according to the invention.
[0070] The present invention in one aspect relates to a method for the preparation of the crystalline Compound 1 Form B comprising the steps of preparing a suspension of Compound 1 in a solvent selected from the group consisting of water or tetrahydrofuran or mixtures thereof and crystallizing Compound 1 Form B by cooling crystallization, evaporative crystallization by anti-solvent addition, vapor diffusion into liquid crystallization, vapor diffusion onto a solid crystallization, or crystallization by wet milling.
[0071] In certain embodiments, a second solvent (co-solvent or anti-solvent) is used in an amount between 5% and 95% (v/v) with an amount of first solvent between 95% and 5% (v/v), preferably between 15% and 85% (v/v) with an amount of first solvent between 85% and 15% (v/v), more preferably between 25% and 75% (v/v) with an amount of first solvent between 75% and 25% (v/v), and most preferably between 35% and 65% (v/v), with an amount of first solvent between 65% and 35% (v/v).
[0072] In a preferred embodiment, the solvent is a mixture of water and tetrahydrofuran. In a more preferred embodiment, the solvent is a 1:1 (v/v) mixture of water and tetrahydrofuran.
Pharmaceutical Compositions
[0073] Compound 1 Form A and Compound 1 Form B may be formulated as a pharmaceutical composition in a manner similar to the pharmaceutical compositions disclosed in U.S. Pat. Nos. 7,601,874 and 7,999,010. Such pharmaceutical compositions comprise Compound 1 Form A or Compound 1 Form B and one or more pharmaceutically acceptable carriers, wherein the Compound 1 Form A or Compound 1 Form B is present in the composition in an amount that is effective to treat the condition of interest. Typically, the pharmaceutical compositions of the present invention include Compound 1 Form A or Compound 1 Form B in an amount ranging from 0.1 mg to 250 mg per dosage depending upon the route of administration, and more typically from 1 mg to 60 mg. Appropriate concentrations and dosages can be readily determined by one skilled in the art.
[0074] Pharmaceutically acceptable carriers are familiar to those skilled in the art. For compositions formulated as liquid solutions, acceptable carriers include saline and sterile water, and may optionally include antioxidants, buffers, bacteriostats and other common additives. The compositions can also be formulated as pills, capsules, granules, or tablets which contain—in addition to Compound 1 Form A or Compound 1 Form B—diluents, dispersing and surface-active agents, binders, lubricants, and/or delayed releases agents. One skilled in this art may further formulate Compound 1 Form A or Compound 1 Form B in an appropriate manner, and in accordance with accepted practices, such as those disclosed in Remington's Pharmaceutical Sciences, Gennaro, Ed., Mack Publishing Co., Easton, Pa. (current edition, the relevant sections of which are incorporated herein by reference in their entirety).
Utility and Methods of Administration
[0075] Compound 1 and its novel crystalline forms, i.e., Compound 1 Form A and Compound 1 Form B, have activity as SHIP1 modulators and therefore may be used to treat any of a variety of diseases, disorders or conditions in a mammal, preferably a human, that would benefit from SHIP1 modulation. Such diseases, disorders or conditions are disclosed in PCT Published Patent Application Nos. WO 2014/143561 and WO 2014/158654.
[0076] Accordingly, an embodiment of the invention is a method modulating SHIP1 activity in a mammal comprising administering an effective amount of Compound 1 Form A or Compound 1 Form B or an effective amount of a composition comprising Compound 1 Form B or Compound 1 Form A to the mammal in need thereof.
[0077] Another embodiment is a method for treating a disease, disorder or condition associated with SHIP1 activity in a mammal comprising administering an effective amount of Compound 1 Form A or Compound 1 Form B or an effective amount of a composition comprising Compound 1 Form A or Compound 1 Form B to the mammal in need thereof.
[0078] Such methods include administering to a mammal, preferably a human, Compound 1 Form A or Compound 1 Form B in an amount sufficient to treat the disease, disorder or condition. In this context, “treat” includes prophylactic administration. Such methods include systemic administration of Compound 1 Form A or Compound 1 Form B, preferably in the form of a pharmaceutical composition as discussed above. As used herein, systemic administration includes oral and parenteral methods of administration. For oral administration, suitable pharmaceutical compositions include powders, granules, pills, tablets, and capsules as well as liquids, syrups, suspensions, and emulsions. These compositions may also include flavorants, preservatives, suspending, thickening and emulsifying agents, and other pharmaceutically acceptable additives. For parenteral administration, the compounds of the present invention can be prepared in aqueous injection solutions which may contain buffers, antioxidants, bacteriostats, and other additives commonly employed in such solutions.
Methods of Preparation
[0079] Representative crystalline forms of Compound 1 of the invention were prepared according to Methods A to J, as described below and subsequently analyzed. Representative crystalline forms of Compound 1 were aged by Method J and subsequently analyzed. It will be appreciated that in the following general methods, solvents used, relative amounts of solvents, and other parameters such as cooling rates, temperatures, times, etc. can be altered to suit needs, up or down by up to 50% without significant change in expected results.
Method A: Crystallization by Slurry Conversion and Evaporative Crystallization
[0080] A 26.4 mg aliquot of amorphous solid was solid dosed in a 1.8 mL glass vial. Ethanol was added in defined aliquots (ex. 100 μL) until about 50% of the solid had dissolved (200 μL final volume). The vial was incubated at elevated temperature for a period of time followed by cooling to ambient temperature. After prolonged incubation, the solid was separated from the liquid by centrifugation. The solid was dried under ambient conditions and analyzed by XRPD. The solvent was further evaporated under ambient conditions and the remaining solids analyzed by XRPD.
[0081] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvents methanol, acetone, isopropanol, ethyl acetate, 2-butanone, tert-butyl methyl ether, 1,4-dioxane, acetonitrile, tetrahydrofuran, cyclohexane, chloroform, toluene, heptane, cumene, p-xylene, anisole, isopropyl acetate, and 1,2-dimethoxyethane.
Method B: Crystallization by Evaporative Crystallization
[0082] A 20.4 mg aliquot of amorphous solid was dissolved in a mixture of methanol and toluene (50:50, (vv)), in a vial. The vial was heated to elevated temperature and the solution filtered through a 0.45 μm PTFE filter, as needed, to obtain a clear solution. Subsequently, the solvents were removed by evaporation at 500 mbar vacuum until completely dry (50 hr). Solid was collected from the vials and analyzed by XRPD.
[0083] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvent pairs tetrahydrofuran/ethanol, water/acetonitrile, 1-butanol/isopropyl ether, isopropanol/dichloromethane, tert-butyl methyl ether/2-methoxyethanol, cumene/1,2-dimethoxyethane, heptane/ethanol, chloroform/ethyl formate and water/1,4-dioxane.
Method C: Crystallization by Anti-Solvent Addition
[0084] A 39.7 mg aliquot of amorphous solid was dissolved in a water (100 μL). Acetonitrile (400 μL), as anti-solvent, was added to the vial of the clear solution. Precipitated solid was collected by centrifugation, dried under ambient conditions and analyzed by XRPD.
[0085] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvent/anti-solvent pairs ethanol/heptane, dichloromethane/toluene, tetrahydrofuran/p-xylene, isopropanol/methylcyclohexane, methanol/chloroform, ethanol/anisole, 2-methyltetrahydrofuran/isopropyl acetate, and 1,4-dioxane/cyclohexane, N,N-dimethylacetamide/n-pentane.
Method D: Crystallization by Cooling
[0086] A solution of amorphous solid (121 mg/mL) was prepared in a solvent mixture of methanol and acetonitrile (400 μL, 50/50 (v/v)), using 40.7 mg of amorphous solid. The slurry mixture was heated, with stirring, to elevated temperature and passed through a preheated 0.45 μm PTFE filter to provide a clear solution. The solution was subjected to a cooling profile, for example, cooling to 5° C. with a cooling rate of 1° C./minute. The sample was kept cold for an extended period before the precipitated solid was separated from the liquid. The solid was dried under ambient conditions and analyzed by XRPD.
[0087] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvent mixtures ethyl formate/1-butanol, 2-methyltetrahydrofuran/cumene, isopropanol/chloroform, isopropyl acetate/ethanol, 1,4-dioxane/tert-butyl methyl ether, p-xylene/dichloromethane, 2-methoxyethanol/1,2-dimethoxyethane, and cyclohexane/ethanol.
Method E: Crystallization by Thermocycling
[0088] A 27.7 mg aliquot of amorphous solid was solid dosed in a 1.8 mL vial and isopropanol (200 μL) was added at ambient temperature. The vial was subjected to a temperature profile of heating and cooling between high (ex. 50° C.) and low (5° C.) temperatures, for three distinct cycles, for example, each heating cycle was at 10° C./hr while the cooling cycles were at −20° C./hr, −10° C./hr and −5° C./hr, for each cycle respectively, finishing at ambient temperature. Upon completion of the thermo-profile, the resulting solid was separated from the liquid by centrifugation and dried under ambient conditions before being analyzed by XRPD.
[0089] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvents 1,2-dimethoxyethane, acetonitrile, ethyl formate, 2-ethoxyethanol, tetrahydrofuran, p-xylene, isopropanol, butyl acetate, tert-butyl methyl ether, 1,4-dioxane, methanol/water (60 to 80/40 to 20 (v/v)), acetonitrile/water (80 to 98/20 to 2 (v/v)), and isopropanol/water (80 to 90/20 to 10 (v/v)).
Method F: Crystallization by Vapor-Diffusion-onto-Solid
[0090] A 1.8 mL vial was charged with 20.0 mg of amorphous solid. The vial was left open and placed in a larger container with a small amount (2 mL) of 1,4-dioaxne as the anti-solvent. After an extended period of exposure to the solvent vapors at room temperature, the resulting solid was collected and analyzed by XRPD.
[0091] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the anti-solvents 1,2-dimethoxyethane, methyl formate, isopropyl ether, n-pentane, dichloromethane, isopropanol, acetonitrile, chloroform and toluene.
Method G: Crystallization by Vapor-Diffusion-into-Solution
[0092] A saturated solution was generated by dissolving 46.1 mg aliquot of amorphous solid, in a vial, in water (100 μL). The vial was left open and was placed in a larger closed container with a small amount (2 mL) of acetonitrile, as the anti-solvent. After an extended period of incubation, the resulting precipitated solid was separated from the liquid by centrifugation, dried under ambient conditions and analyzed by XRPD.
[0093] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvent/anti-solvent pairs methanol/heptane, tetrahydrofuran/hexane, ethanol/chloroform, isopropanol, 2,2,4-trimethylpentane, dichloromethane/diethyl ether, 1,4-dioxane/tert-butyl methyl ether, N,N-dimethylformamide/toluene, tetrahydrofuran/cyclopentane, and dichloromethane/n-pentane.
Method H: Crystallization by Single-Solvent Drop Grinding
[0094] A stainless steel RETSCH® grinding container was charged with a 19.2 mg aliquot of amorphous solid and ethyl acetate (10 μL) was added. The vial was mounted in a RETSCH® MM301 ball mill and ground at a defined frequency (ex. 30 Hz). After grinding for a defined time (ex. one hour), the resulting solid was collected and analyzed by XRPD.
[0095] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing the solvent isopropanol, chloroform, decane, cumene, anisole, acetonitrile, cyclohexane, p-xylene, and 1,2-dimethoxyethane
Method I: Quantitative Solubility Assessment and Crystallization
[0096] The solubility of 1 in a solvent or solvent mixture was determined at room temperature. A 20 mg aliquot of 1 (amorphous) was weighed in a standard 1.8 mL HPLC vial. Subsequently, isopropanol (200 μL) was added and the vial was left to equilibrate at room temperature with continuous stirring. After 24 hours, the solid was separated from the liquid by centrifugation and analyzed by XRPD. Subsequently the remaining liquid phase was further filtered through a 0.45 μm PTFE filter to remove any particulate matter. The concentration of the 1 in solution was determined by HPLC-DAD analysis using a calibration curve made from two independent stock solutions of the 1 prepared in 0.1% TFA in water/acetonitrile (50:50).
[0097] By similar techniques, a person skilled in the art would be able to obtain similar results utilizing a variety of solvents.
Method J: Accelerated Aging Analysis by XRPD
[0098] Samples collected from the crystallization conditions were subjected, as is, to accelerated aging conditions of 40° C. and 75% relative humidity for 48 hours, via standard methods and analyzed by XRPD.
[0099] The following Examples are provided for purposes of illustration, not limitation. In summary, the following Examples disclose the preparation, analysis and characterization of Compound 1 Form A and Compound 1 Form B of the invention. One of ordinary skill in the art understands that experimental differences may arise due to differences in instrumentation, sample preparation, or other factors.
Example 1
Preparation of Compound 1 Form A for XRPD, DSC and TGA Analysis
[0100] Compound 1 Form A was generated through a modified Method B procedure. Amorphous Compound 1 (100 mg) was suspended in a 5:1 (v/v) mixture of methanol (250 μL) and of isopropyl acetate (50 μL). The mixture was heated up to 75° C. and kept at this temperature for about 30 minutes until all remaining material was dissolved. Heating was subsequently removed and the mixture left to slowly cool to room temperature. After several hours, white material started to precipitate. After 24 hours, white solid was filtered, washed using cold isopropyl acetate and air-dried for about 24 hours. Dry solid was manually ground, by mortar and pestle, yielding a fine white powder, i.e., Compound 1 Form A, in the mortar, which was analyzed by XRPD, DSC and TGA.
Example 2
Preparation of Compound 1 Form B for XRPD, DSC, and TGA Analysis
[0101] Compound 1 Form B was generated through a modified Method B procedure. Amorphous Compound 1 (20.4 mg) was suspended in water (104 μL) containing trifluoroethanol (0.01% (v/v)). The mixture was kept at 21° C. and stirred using a stirring bar for 115 hours. The solvent was slowly evaporated under ambient conditions and remaining solid was left for drying. The dry material was manually ground, by mortar and pestle, yielding a fine white powder in the mortar, i.e., Compound 1 Form B, which was analyzed by XRPD, DSC and TGA.
Example 3
X-Ray Diffraction Spectrometry Experimental Conditions
[0102] Dry solid samples from Examples 1 and 2, were transferred into a boron-glass capillary with 0.3 mm outer diameter. The capillary was mounted on the goniometer head and placed in the D8 Advance Bruker-AXS Diffractometer equipped with solid state LynxEye detector. The capillary was spinning during data recording, at 15 rpm. The XRPD platform was calibrated using Silver Behenate for the long d-spacings and Corundum for the short d spacings.
[0103] Data collection for Compound 1 Form A and Compound 1 Form B, were carried out, in transmission mode, at ambient conditions (˜23° C. and ˜100 kPa) using monochromatic CuK α1 radiation (1.54056 Å) in the 2Θ region between 4° and 45°, with an exposure time of 90 s for each frame and 0.016° increments. No additional corrections were made during data collection.
[0104] Peak selection was performed using DIFFRACP plus EVA software package (Bruker-AXS, 2007), using a second derivative method working on data prepared by Savitzky-Golay (Savitzky, A. & Golay, M. J. E. (1964) Anal. Chem. 36, 1627) smoothing filter with the following criteria:
1. Peak width: The algorithm uses 5 to 57 data points centered on the point of interest, and a peak is selected from the second derivate if the peak width lays within the range FWHM<Peak width<4×FWHM. Peak widths for 1 Form A and 1 Form B were 0.2 and 0.3°, respectively. 2. Threshold: Based on the comparison of the computed maximum of the peak with the middle of the chord joining 2 inflection points of both sides of maximum. According to Equation 1, a peak was accepted if I P was greater than the intensity at chord center (I M ) plus a factor comprising a threshold value of 1.0 multiplied by the square root of I M , as described in the software manual (DIFFRAC PLUS EVA Manual (2007) Bruker-AXS, Karlsruhe):
[0000] I P >I M +T ×√{square root over ( I M )} (Equation 1)
Where: I P =peak intensity; I M =intensity at chord center; T=threshold.
[0108] The XRPD diffractogram from Example 3 are shown in FIG. 2 for Compound 1 Form A and FIG. 10 for Compound 1 Form B, and are indicative of diffractograms generated from material for Compound 1 Form A and Compound 1 Form B performed by alternative crystallization methods.
[0109] In addition, crystalline material of Compound 1 Form A was subjected to Method J and analyzed by XRPD and found to yield diffractograms that were equivalent to FIG. 2 .
[0110] The diffractogram presented in FIG. 1 was recorded on D8 Discover Bruker-AXS diffractometer using Cu K α radiation (1.54178 Å) equipped with 2D GADDS detector in transmission mode. The sample of amorphous Compound 1 was placed in the flat transmission sandwich-like 4.5 mm diameter sample holder protected by X-Ray transparent mylar foil. During the measurement sample was oscillated in x,y direction (perpendicular to the primary beam) with 1.75 mm radius. Data collection was carried out in two frames 1.5<2θ<21.5° and 19.5<2θ<41.5° and separately integrated with step size 0.04°. The final powder pattern was obtained by merging both frames using area between 19.5<2θ<21.5° as common share. Peaks were analyzed as described above.
Example 4
Single-Crystal X-Ray Diffraction Experimental Conditions
[0111] A 1-dram vial was charged with Compound 1 (30 mg) and diluted with methanol (0.3 mL). To the resulting solution was added methyl tert-butyl ether (0.4 mL) and the vial sealed and allowed to stand at room temperature for 2 weeks. These conditions afforded colorless crystals approximately 0.5 cm in length as overlapping, layered plates, approximately 1 mm in thickness. The remaining solvent was removed by decanting and the crystals were allowed to dry at room temperature overnight
[0112] Suitable single crystal was selected and mounted on a Mitegen Micromount with a UV curable adhesive, which was then mounted on an X-ray diffraction goniometer (Bruker SMART X2S crystallographic system, Delft, The Netherlands). X-ray diffraction data were collected for these crystals at −73° C., using monochromatized (Doubly Curved Silicon Crystal) MoK α radiation (0.71073 Å), from a sealed MicroFocus tube. Generator settings were 50 kV, 1 mA.
[0113] Data were acquired using three sets of Omega scans at different Phi settings and the frame width was 0.5° with an exposure time of 5.0 s. The detailed data collection strategy was as follows:
[0000]
Detector distance: 40 mm; Detector swing
angle (fixed 2 Theta): −20°
Run
Omega (start)
Omega (end)
Phi
Frames
1
−20.0
160.0
0
360
2
−20.0
100.0
120.0
240
3
−20.0
40.0
240.0
120
[0114] Of the 7287 reflections that were collected, 3603 were unique (R int =0.047); equivalent reflections (excluding Friedel pairs) were merged. Data were integrated using the Bruker SAINT software package (Version 7.68A. Bruker AXS Inc., Madison, Wis., USA (1997-2010)). The linear absorption coefficient, μ, for Mo-Kα radiation is 0.80 cm −1 . Data were corrected for absorption effects using the multi-scan technique (SADABS), with minimum and maximum transmission coefficients of 0.534 and 0.961, respectively (SADABS. Bruker Nonius area detector scaling and absorption correction—V2008/1, Bruker AXS Inc., Madison, Wis., USA (2008)). The data were corrected for Lorentz and polarization effects.
[0115] The structure was solved by direct methods (SIR97—Altomare A., Burla M. C., Camalli M., Cascarano G. L., Giacovazzo C., Guagliardi A., Moliterni A. G. G., Polidori G., Spagna R. (1999) J. Appl. Cryst. 32, 115-119). All non-hydrogen atoms were refined anisotropically. All O—H and N—H hydrogen atoms were located in difference maps and refined isotropically. All other hydrogen atoms were placed in calculated positions. No attempt was made to ascertain the correct absolute configuration of the molecule, due to the weak anomalous signal from the sample. The final cycle of full-matrix least-squares refinement (function minimized was Σw (Fo 2 −Fc 2 ) 2 ) on F 2 was based on 3603 reflections and 268 variable parameters and converged (largest parameter shift was 0.00 times its esd) with unweighted and weighted agreement factors of:
[0000] R 1=Σ∥ F o |−|F c ∥/Σ|F o |=0.047, I> 2σ( I )
[0000] wR 2=[Σ( w ( F o 2 −F c 2 ) 2 )/Σ w ( F o 2 ) 2 ] 1/2 =0.135, all data
[0116] The standard deviation of an observation of unit weight ([Σw(F o 2 −F c 2 ) 2 /(N o −N v )] 1/2 , where N o =number of observations and N v =number of variables) was 1.07. The weighting scheme was based on counting statistics. The maximum and minimum peaks on the final difference Fourier map corresponded to 0.25 and −0.18 e − /Å 3 , respectively. Neutral atom scattering factors were taken from Cromer and Waber (Cromer, D. T. & Waber, J. T.; “International Tables for X-ray Crystallography”, Vol. IV, The Kynoch Press, Birmingham, England, Table 2.2A (1974)). Anomalous dispersion effects were included in Fcalc (Ibers, J. A. & Hamilton, W. C.; Acta Crystallogr., 17, 781 (1964)); the values for Δf′ and Δf″ were those of Creagh and McAuley (Creagh, D. C. & McAuley, W. J.; “International Tables for Crystallography”, Vol C, (A. J. C. Wilson, ed.), Kluwer Academic Publishers, Boston, Table 4.2.6.8, pages 219-222 (1992)). The values for the mass attenuation coefficients are those of Creagh and Hubbell (Creagh, D. C. & Hubbell, J. H.; “International Tables for Crystallography”, Vol C, (A. J. C. Wilson, ed.), Kluwer Academic Publishers, Boston, Table 4.2.4.3, pages 200-206 (1992)). All refinements were performed using the SHELXL-9710 via the WinGX11 interface (Sheldrick, G. M. 2008. Acta Cryst. A64, 112-122, WinGX—V1.70—Farrugia, L. J.; J. Appl. Cryst., 32, 837 (1999)).
[0117] Data was visualized using Mercury CSD 2.0 (Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466). A representation of the crystal structure from this Example is shown in FIGS. 5 and 7 . The details of this crystal structure were used in Example 5.
Example 5
Comparison of Compound 1 Form a Experimental XRPD and Single-Crystal-Derived Simulated XRPD Diffractograms
[0118] The simulated powder data from the single crystal of Compound 1 Form A, described in Example 4, was performed using Mercury Package, version 3.5.1 (Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466). The peak positions were calculated based on the crystal symmetry and unit cell parameters, while the peak intensities were calculated from electron density based on the atom positions within the asymmetric unit. The following restraints were applied. The radiation used was CuK α1 (1.54056 Å). The Lorentz-polarization correction typical for a laboratory X-ray source with the fixed slit widths. Neither absorption nor background correction was included. All non-hydrogen atoms were assumed to have isotropic atomic displacement parameters (U iso ) of 0.05 Å 2 . Hydrogen atoms for which 3D coordinates are taken into account and assigned U iso values of 0.06 Å 2 . The powder pattern simulator was allowed to take site occupation factors into account to correct the patterns generated for disordered structures read from CIF and SHELX Res files. All reflections have a symmetric pseudo-Voight peak shape with a full width half maximum of 0.1 degree 20, corresponding to D8 Advance Resolution.
[0119] For comparison of the simulated powder pattern for the single crystal data with the experimental one, both patterns were converted in (x,y) ASCII files and overlaid. No other additional action was taken. FIG. 6 depicts the comparison of Compound 1 Form A experimental XRPD and single-crystal-derived simulated XRPD diffractograms.
Example 6
Thermal Analysis Experimental Conditions
[0120] Compound 1 Form A and Compound 1 Form B material from Examples 1 and 2, respectively, were used for thermal analysis.
[0121] DSC Analysis: Melting properties were obtained from DSC thermograms, recorded with a heat flux DSC822e instrument (Mettler-Toledo GmbH, Switzerland). The DSC822e was calibrated for temperature and enthalpy with a small piece of indium (m.p.=156.6° C.; ΔH f =28.45 J/g). Samples were sealed in standard 40 microliter aluminum pans and heated in the DSC from 25° C. to 300° C., at a heating rate of 10° C./min. Dry N 2 gas, at a flow rate of 50 ml/min, was used to purge the DSC equipment during measurement. Representative DSC data from Example 3 can be found in FIG. 3 for Compound 1 Form A and FIG. 11 for Compound 1 Form B and are indicative of DSC data generated from material for Compound 1 Form A and Compound 1 Form B performed by alternative crystallization methods.
[0122] TGA/MS Analysis: Mass loss due to solvent or water loss from the crystals, from Examples 1 and 2, were determined by TGA/SDTA analysis. Monitoring of the sample weight, during heating in a TGA/SDTA851e instrument (Mettler-Toledo GmbH, Switzerland), resulted in a weight vs. temperature curve for each sample. The TGA/SDTA curves for Compound 1 Form A and Compound 1 Form B are in FIGS. 4 and 12 , respectively and are indicative of TGA/SDTA data generated from material for Compound 1 Form A and Compound 1 Form B performed by alternative crystallization methods. The TGA/SDTA851e was calibrated for temperature with indium and aluminum. Samples, from Examples 1 and 2, were weighed into 100 μL aluminum crucibles and sealed. The seals were pin-holed and the crucibles heated in the TGA from 25° C. to 300° C. at a heating rate of 10° C./min. Dry N 2 gas was used for purging. TGA/MS data for Compound 1 Form B is in FIG. 13 and is indicative of TGA/MS data generated from material for Compound 1 Form B performed by alternative crystallization methods.
Example 7
Crystallization of Compound 1 Form A by Method D
[0123] A solution of about 100 mg/mL of Compound 1 was prepared using 39.4 mg of amorphous Compound 1 and 400 μL of an isopropyl acetate/ethanol (50/50 (v/v)) solvent mixture at ambient temperature in a 1.8 mL vial. The solution was heated to 60° C., with a heating rate of 10° C./min, and stirred at 30 rpm, using a Teflon®-coated magnetic stirring bar with dimensions 7 mm in length and 2 mm in width, and subsequently passed through a preheated 0.45 μm PTFE filter to provide a clear solution. The solution was kept at 60° C. for one hour and then cooled to 5° C. with a rate of 1° C./hour. The solution was constantly stirred, as above. The solution was kept at 5° C. for 48 hours and then precipitated solid was collected by centrifugation (3000 rpm for 10 minutes) followed by solvent removal by Pasteur pipette. Solids were dried under ambient conditions and analyzed by XRPD.
Example 8
Crystallization of Compound 1 Form A by Method E
[0124] 20.0 mg of amorphous Compound 1 was solid dosed in a 1.8 mL vial and 100 μL of a methanol/water mixture (60/40 (v/v)) was added at ambient temperature. The solution was subjected to a temperature profile of heating and cooling between 50° C. and 5° C. for three cycles, each heating cycle was at 10° C./hr while the cooling cycles were at −20° C./hr, −10° C./hr and −5° C./hr, for each cycle, respectively, finishing at ambient temperature. During the entire experiment the mixture was stirred at 30 rpm using a magnetic stirrer and a TEFLON®-coated magnetic stirring bar with dimensions 7 mm in length and 2 mm in width.
[0125] Upon completion of the thermo-profile, the solid was collected by centrifugation (3000 rpm for 10 minutes) followed by solvent mixture removal by Pasteur pipette and dried under ambient conditions for one hour, before being analyzed by XRPD.
Example 9
Crystallization of Compound 1 Form A by Method G
[0126] 41.2 mg of amorphous Compound 1 was solid dosed into a 1.8 mL vial and dissolved in isopropanol (600 μL). The vial was left open and placed in a larger closed container with 2 mL of 2,2,4-trimethylpentane, antisolvent, which was sealed and left for 14 days. The precipitated solid was collected by centrifugation (3000 rpm for 10 minutes) followed by solvent mixture removal by Pasteur pipette and dried under ambient conditions for one hour, before being analyzed by XRPD.
Example 10
Crystallization of Compound 1 Form A by Method H
[0127] 20.5 mg of amorphous Compound 1 was added to a 2.5 mL stainless steel RETSCH® grinding container. Subsequently, 10 μL of isopropanol was added, along with 2 stainless steel balls (2 mm diameter). The container was sealed and mounted in a RETSCH® MM301 ball mill and the material was ground at a frequency of 30 Hz at close to ambient conditions (temperature of 23° C. and pressure ˜100,000 Pa), for one hour. The steel balls were removed and material collected and analyzed by XRPD.
Example 11
Crystallization of Compound 1 Form B by Method I
[0128] Amorphous Compound 1 (19.7 mg) was suspended in 100 μL water in 1.8 mL vial. The obtained slurry was stirred at ambient conditions (temperature of 23° C. and pressure ˜100,000 Pa) for 14 days. During the entire experiment, the solution was stirred at 30 rpm, using magnetic stirrer, and a TEFLON®-coated magnetic stirring bar with dimensions 7 mm in length and 2 mm in width. Upon completion, the mixture was centrifuged (speed: 3000 rpm, time: 10 min) and the liquid was removed using Pasteur pipette. The remaining wet solids were dried under air, at ambient conditions, for one hour before being analyzed by XRPD.
Example 12
Crystallization of Compound 1 Form B by Method D
[0129] A solution of about 100 mg/mL of Compound 1 was prepared using 40.4 mg of amorphous Compound 1 (amorphous) and 200 μL of a water/tetrahydrofuran (50/50 (v/v)) solvent mixture, at ambient temperature, in a 1.8 mL vial. The solution was heated to 60° C., with a heating rate of 10° C./min, and stirred at 30 rpm, using a TEFLON®-coated magnetic stirring bar with dimensions 7 mm in length and 2 mm in width, and subsequently passed through a preheated 0.45 μm PTFE filter to provide a clear solution. The solution was kept at 60° C. for one hour and then subjected to a cooling profile of cooling to 5° C. with a cooling rate of 1° C./hour. Solution was constantly stirred, as above. Solution was kept at 5° C. for 48 hours and then precipitated solid was collected by centrifugation (3000 rpm for 10 minutes) followed by solvent removal by Pasteur pipette. Solids were dried under ambient conditions and analyzed by XRPD.
Example 13
Preparation of Compound 1 Form A for FT-IR and Raman Spectroscopy
[0130] Compound 1 Form A was generated through a modified Method C procedure, followed by a modified Method D procedure. To a solution of methanol (45.7 g; 58.1 mL; 1:0.79 w/w) and Compound 1 (57.9 g; 0.15 mmol; 1:1 w/w) in a round bottom flask at 25-30° C. was added tert-butyl methyl ether (171.2 g; 231.0 mL; 1:2.96 w/w) drop-wise over a period of 45 minutes at 25-30° C. The reaction mass was slowly cooled to 8±2° C. and stirred at the same temperature for 45 minutes. After 45 minutes, the reaction mass was filtered and the cake washed with chilled tert-butyl methyl ether (85.6 g; 115.5 mL; 1:1.48 w/w). The product was dried under vacuum at 25±5° C. to afford 55.0 g of the purified Compound 1 Form A material (HPLC purity of 99.8 area %) which was used for FT-IR and Raman shift spectroscopy.
Example 14
FT-IR Spectroscopy Experimental Conditions
[0131] Compound 1 Form A material from Example 13 was used for FT-IR analysis.
[0132] FT-IR analysis was performed using a Thermo Nicolet Avatar 370 FT-IR instrument and FT-IR spectra were presented using GRAMS/AI spectroscopy software version 8.00. Instrument parameters were as follows: Number of scans=16, Number of background scans=16, Resolution=2.000, Sample gain=8.0, Mirror velocity=0.6329 and Aperture=100.00. Air background spectra were collected before the sample analysis. Representative FT-IR spectroscopy data for Compound 1 Form A, from Example 14 can be found in FIG. 8 and are indicative of FT-IR spectroscopy data generated from material for Compound 1 Form A performed by alternative crystallization methods.
Example 15
Raman Shift Spectroscopy Experimental Conditions
[0133] Compound 1 Form A material from Example 13 was used for Raman shift analysis.
[0134] Raman spectroscopy analysis was performed using a Raman station Avalon Instruments, software version 5.4.3.4 with cyclohexane used as a standard solvent for calibration and as reference spectrum for peak picking. The sample of powder was placed on a clean glass slide and placed directly below the laser pathway. Spectral data was collected using an exposure of 5 s×5 exposures to ensure powder was homogeneous and the collected spectra represented the bulk material. Representative raman shift spectroscopy data for Compound 1 Form A, from Example 15 can be found in FIG. 9 and are indicative of raman shift spectroscopy data generated from material for Compound 1 Form A performed by alternative crystallization methods.
[0135] All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications, including U.S. provisional patent application Ser. No. 62/185,416, filed Jun. 26, 2015, referred to in this specification are incorporated herein by reference in their entireties.
[0136] Although the foregoing invention has been described in some detail to facilitate understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the described embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims. | The present invention is generally directed to novel crystalline forms of the acetate salt of (1S,3S,4R)-4-((3aS,4R,5S,7aS)-4-(aminomethyl)-7a-methyl-1-methyleneoctahydro-1H-inden-5-yl)-3-(hydroxymethyl)-4-methylcyclohexanol and processes for their preparation. | 2 |
INTRODUCTION
[0001] The present invention relates to a magnetic field detector for detection of motion or standstill. More specifically, the invention relates to a method and an apparatus for detection of a specific sequence of motions that initiates activation of an event.
PRIOR ART
[0002] Motion detection in oil and gas wells has proven to be difficult. When running different tools into the well, it is important to receive feedback as to whether the tool responds to various activation signals that are sent to the tool. As a consequence of large well depths, it may be difficult to know whether a tool is doing what it is supposed to do. It may take a long time before motion or standstill of a tool can be determined at the surface. Traditionally, it has simply been established whether a tool is moving by observing the motion of a string, such as a drill string, coiled tubing or the like at the surface. This works nicely if the well is not too deep, and also provided that a string is in fact used, such as a drill string, coiled tubing or the like. As deeper wells have been drilled, it has been desirable to use to a greater extent, tools which do not hang down from said string, such as a drill string, coiled tubing or the like because the long connections involve greater costs, are more subject to failure in the form of cable breaks etc., and take a long time to run up and down in the well. At great depths, the traditional way of detecting motion or standstill is thus inadequate. The string, drill string, coiled tubing or the like can be moved relatively far on the surface without it being possible to determine unequivocally whether the tool is actually moving in the well, because the connection between the tool and the surface may expand or be compressed quite substantially without the tool far down in the well moving. This is shown in FIGS. 2 a - d . The broken line indicates the drill string under tension. The difference between the broken line and the solid line indicates slack that must be drawn out before motion on the drill floor is detected downhole. FIG. 2 a shows slack in a drill string, FIG. 2 b shows vertical tension; no slack apart from stretch in the string, FIG. 2 c shows angle; delayed motion downhole as motion on the surface helps to draw in slack, FIG. 2 d shows horizontal tension; delayed motion downhole as the motion on the surface helps to draw in slack.
[0003] The instruments used for motion detection may be arranged on the tool that is run down into the well without their comprising any means of communication, or possibly only comprising means for one-way communication. Such instruments may, for example, be used to prevent other equipment from being activated when a tool is in motion, for one-way communication from the surface to a tool etc.
[0004] Measuring motion by using one or more accelerometers is a well-known, tried and tested method. An accelerometer measures acceleration, not motion, but as all motion starts and stops with an acceleration, the accelerometer can be used for motion detection. However, the use of accelerometers to detect motion is associated with a number of drawbacks. The accelerometer is inaccurate and requires relatively large and powerful motions in order to provide readings. At great depths, as mentioned, large motions at the surface can be dampened substantially in that the connection expands or is compressed, and the resultant motion of the tool downhole may be so weak and slow that the accelerometer does not give a clear reading. In addition, an accelerometer will not distinguish between a steady motion and standstill, as both these situations are characterised by the absence of acceleration. FIG. 1 b shows measurements from an accelerometer. The figure shows no values, but is intended to illustrate how an accelerometer merely registers change of speed, positive or negative, not constant speed.
[0005] Measuring motion by using pressure sensors has also been used to determine whether a tool is in motion or is at a standstill. As a tool moves up or down in a well, the fluid column above the tool and the resulting pressure to which the tool is subjected will change. These changes in pressure can be used to determine whether the tool has moved further up or down in the well. This method requires the tool to move a long way in the vertical direction in order to establish clearly what motion has taken place. Motions over smaller distances will not give clear readings on a pressure sensor. In addition, the method is not suitable for detection of motion or standstill in a horizontal direction or rotational motion.
[0006] Various forms of wave signal analysis have also been used to detect motion or standstill. A wave signal analysis system as a rule transmits a wave signal, either in the form of light, sound or radio waves, and listens to an echo or a reflection. By measuring the delay, it is possible to determine distance to the object that reflects the wave signal. If this distance changes, it may be concluded that a motion has taken place. By in addition looking at the change in frequency, it is possible to determine the speed of the reflecting object. If the speed is greater than zero, motion has been detected. Wave analysis can be very difficult to implement in environments where there is no homogeneous medium in which the wave signals can travel. In an oil or gas well, the wave signals will have to travel in many different types of media, for example, oil, natural gas, water, oil-based mud, water-based mud, metal, air, etc. Each of these materials will distort and/or reflect the wave signals differently. Although widely used for motion detection in oil and gas wells, wave signal analysis has many and clear limitations. It is costly, complex, time-consuming and gives unreliable measurements.
[0007] Different types of magnetic field measurements have been in use for many years and are, in some applications, a well-known, tried and tested technology. The most common application of these measurements is direction finding. In such an application, the earth's magnetic field is used to determine direction. Magnetic field measurements can also be used to detect joints (ref. Patent GB-2422622A), or irregularities (ref. U.S. Pat. No. 6,768,299B2) in, for example, steel pipes. These are common areas of application in the oil and processing industries. Systems have also been developed which are so advanced that they can, for example, determine thread type in joints (ref. U.S. Pat. No. 709,522B2). Detection of joints can also be used to determine position in a well. If a certain number of joints have been detected and the distance between the joints is known, the distance the measuring point has covered can be found.
[0008] What is considered to be novel and advantageous about the present invention is the use of magnetic field sensors which measure a surrounding magnetic field to detect motion or standstill of an object over time, and the use this information to activate an event when a predetermined sequence of motions is registered. By “surrounding magnetic field” is meant a magnetic field set up by the surroundings. Stable fields such as the earth's magnetic field, the magnetic field of a casing pipe, the magnetic field of motionless magnetic materials or the magnetic field of ground rock are regarded as stable surrounding fields. The inventive apparatus is composed of an independent unit that can move in any direction in relation to the surroundings, the apparatus being connected to the object whose motion it is desired to detect. The apparatus may also remain stationary to detect motions of the surroundings in relation to the apparatus.
[0009] U.S. Pat. No. 7,245,299B2 (PathFinder) is regarded as describing the closest prior art. The document describes a method for communicating with a downhole device in order to be able to send control signals to, for example, a directional drilling tool.
[0010] The said document describes a method involving the use of different speeds of rotation or duration of rotation of a drill string. From this a code can be derived that can be interpreted in order to then control, for example, a drilling tool.
[0011] The activation of an event based on an interpretable code has features in common with the present invention, but the way in which the code is generated is very different. The use of a magnetic sensor to measure rotational speed is mentioned as one way of determining rotational speed. Another way is, as mentioned, the use of an optical sensor. The essential aspect of the Pathfinder patent is not the sensor itself, but that the rotational motion per se is used to derive control signals. The magnetic fields that are measured are further set up by permanent magnets mounted on a drill string and with a sensor mounted on a sleeve, where the drill string rotates and the sleeve remains stationary. The measurement of rotational speed is therefore dependent on two mechanical parts which move relative to one another, ref. FIG. 2 a and the explanation thereof.
[0012] This is different from the present invention where magnetic fields for the most part set up by the surroundings are registered, and where the motion detector is composed of just one part that measures motion in relation to the surroundings without any mechanical moving parts. Thus, the detector according to the invention can be used in different ways and not least in different environments.
[0013] The PathFinder solution for the detection of rotational speed makes no major demands on the electronics since it is not necessary to detect differences between each rotation, but only over time. Without fixed points for each rotation, i.e., each registered change in magnetic field, as is the case in the present solution, greater demands will be made on the analysis logic that is to process data from a sensor, since larger amounts of data will have to be compared in order, with certainty, to determine a rotational speed and any change thereof.
[0014] The use of rotational motion as a signal means will impose a limitation of having to perform the method described in PathFinder during a typical drilling operation in which the drill string rotates. The speed and duration of rotation will then be controlled by operators on the surface.
[0015] The present invention is more flexible since it is not limited to rotational motion only, but some form of motion which also includes rotational motion. By distinguishing between motion and non motion, a code can be derived that can be used to activate an event such as controlling a tool. The apparatus that constitutes the invention can thus be used under conditions where a rotational motion cannot be made.
[0016] The present invention describes a method and an apparatus that can be used also in operations other than drilling, such as well completion, maintenance and inspection.
[0017] If the sleeve with magnet-sensitive elements and the mandrel equipped with magnets become interlocked, it will not be possible to communicate with the tool. The invention is implemented in just one part without any moving components, which will ensure that communication is always possible. There is also no need for contact with casing pipes or rock wall to create friction and thus motion between sleeve and mandrel.
[0018] The PathFinder solution requires feedback from the tool downhole up to the surface in order to work in a setting such as drilling, carried out, for example, with mud pulsing. The intelligence controlling the tool is located on the surface, whilst the intelligence in the present solution is located downhole. When an event takes place, the tool will thus know what is to be done.
[0019] The apparatus according to the present invention is an independent unit which detects standstill and all types of motion based on registered changes in magnetic fields. The apparatus can thus be used as an activation apparatus when a predetermined sequence of motion is detected. The apparatus further has means for optimising measured magnetic fields. Optimisation may include self-adjusting filters that are adjusted according to the surroundings in which the apparatus operates so as to thereby obtain clearer measurements.
SUMMARY OF THE INVENTION
[0020] The object of the present invention is to provide a method and an apparatus to activate an event by detecting motion or standstill in a simpler, less costly and more accurate manner than the prior art apparatus and methods.
[0021] Although the exemplary embodiments are for the most part based on problem complexes related to the detection of motion or standstill in oil and gas wells, it should be understood that the invention is not limited to such areas of use and that the invention can be used in all situations where detection of motion is of interest.
[0022] The object of the present invention is achieved with a method that is characterised by the features disclosed in independent claim 1 , and by further advantageous embodiments and features as disclosed in the dependent claims.
[0023] The invention also comprises an apparatus for carrying out said method.
[0024] A detailed description of a number of exemplary embodiments of the present invention is given below with reference to the attached drawings, wherein:
[0025] FIG. 1 shows accelerometer versus magnetic field measurements. Difference between measurements from magnetic field sensor and accelerometer. The figure does not show any values, but is intended to illustrate how an accelerometer only registers a change in speed, positive or negative, not constant speed. By “magnetic field measurements” is meant the difference between current and previous measurements.
[0026] FIG. 1 a shows an example of a sequence of motions of a arbitrary object;
[0027] FIG. 1 b shows an example of what type of measurement signals an accelerometer will give in the case of the sequence of motions indicated in FIG. 1 a ; and
[0028] FIG. 1 c shows an example of what type of measurement signals a magnetic field sensor will give in the case of the sequence of motions indicated in FIG. 1 a.
[0029] FIG. 2 shows an example of how tension in a drill string will result in a different sequence of motions for a tool that is located far downhole than for the part of the drill string that is on the surface. The broken line indicates the drill string under tension. The difference between the broken line and the solid line indicates slack that must be drawn out before motion on the drill floor is registered downhole.
[0030] FIG. 2 a shows slack in a drill string;
[0031] FIG. 2 b shows vertical tension, no slack apart from stretch in the string;
[0032] FIG. 2 c shows angle, delayed motion downhole as motion on the surface helps to take in slack; and
[0033] FIG. 2 d shows horizontal tension, delayed motion downhole as the motion on the surface helps to take in slack.
[0034] FIG. 3 shows examples of typical 1D-measurements from a magnetic field sensor and the readings that may be obtained after the measurements have been processed. An examination of the values from the magnetic field sensor will not give any indication of whether there is motion. It is not until a comparison with previous values is made that motion will be detected. Clear readings are then obtained when there is motion.
[0035] FIG. 3 a shows typical values for the signal going into the sensor;
[0036] FIG. 3 b shows typical values of the absolute value of the difference; and
[0037] FIG. 3 c shows typical values on detection of motion.
[0038] FIG. 4 shows the consequence of motion in a 2-dimensional magnetic field, where the difference in the X direction is given by X 1 -X 2 and the difference in the Y direction is given by Y 1 -Y 2 .
[0039] FIG. 5 is a block diagram showing how the whole system may typically be constructed.
DETAILED DESCRIPTION
[0040] According to the present invention, a magnetic field sensor is used to detect motion or standstill by measuring a variation in magnetic field strength and direction. Motion and standstill can also be measured relative to other magnetic fields, where the system including the sensor remains stationary and magnetic fields in the surroundings move. According to the present invention, measurements of a magnetic field are analysed and compared with one or more previous measurements taken at a given time in advance. If there is a configurable difference between current and previous measurements, the system has detected a motion. This is shown in FIGS. 3 a - c . By placing a filter on the signal from the measurement, the system can be given a sensitivity and function intended for different surroundings and conditions.
[0041] By employing and configuring different filters, the application of the magnetic field detector according to the present invention can be adapted to many different areas of use. To adapt the measurements to the conditions in an oil or gas well, it may be necessary to have filters which, for example, are sensitivity-reducing, comprise buffer solutions and comprise self-calibration.
[0042] One or more sensitivity-reducing filters can, according to the invention, be used to remove noise from the surroundings which otherwise would cause erroneous detection. To compensate for lost sensitivity when using sensitivity-reducing filters, a plurality of magnetic field sensors can be used, and the sampling rate can be increased so that an algorithm used to determine whether there is motion or standstill has a several measurements to compare. By “noise” is meant, for example, unstable magnetic fields from the surroundings, remote or close by.
[0043] According to the present invention, the magnetic field detector may comprise one or more buffer elements adapted so that errors due to sudden magnetic field changes can be eliminated. By using a previous measurement or several previous measurements, it will be possible to reduce the error rate. A buffer element will also reduce the response time from the system. This can be solved by reducing the interval between each measurement. A buffer solution can also be used to eliminate so-called inert changes in magnetic fields that are due to changes in the surroundings. In such an embodiment, a buffer will be able to handle average values over given time intervals where there is either constant motion or standstill. The values are stored and compared with later or earlier values, changes over time being shown as a difference.
[0044] According to one embodiment of the present invention, one or more self-calibration elements can be used in, for example, oil and gas wells which have magnetic fields that vary strongly. The self-calibration elements use the measurements from the magnetic field sensors to set up a magnetic field that is as strong as, but oppositely directed to, the magnetic field set up by the surroundings. By measuring the energy required to set up this field, the strength of the field from the surroundings is measured.
[0045] The magnetic field detector according to the present invention provides a compact, robust, reliable and inexpensive system for detecting motion or standstill. The actual magnetic field sensor is per se known and considered a commercially available product. Suitable magnetic field sensors can be selected on the basis of prevailing needs, and optionally adapted to special applications. The combination of one or more magnetic field sensors with one or more sensitivity-reducing filters, a buffer element and one or more self-calibration elements, will result in a magnetic field detector which can easily be arranged on existing equipment and which can easily be configured and optionally reconfigured to suit different applications. The system can, for example, also be combined with memory means that can be used to register the magnetic field and motion profile of the tool, and thus provide a history log for the tool. A log of this kind may also be configured for self-learning, so that the log data together with real time measurements can be used to configure the filters. This could save the operator a great deal of time and work.
[0046] The magnetic field detector according to the present invention can also be combined with other methods for detecting motion, standstill, acceleration, pressure etc. so as thereby to increase the degree of information. It should be understood that the magnetic field detector according to the present invention can be provided by combining suitable commercially available elements, and that the magnetic field detector could also comprise other elements, such as power supply, communication means such as transmitter and receiver elements, memory means, electromechanics, pneumatics, hydraulics etc.
[0047] According to one embodiment of the present invention, the magnetic field detector comprises a battery and optionally wireless communication means. Such an embodiment will no longer be dependent on the tool on which it is located comprising some form of physical connection with the surface. The magnetic field detector according to this embodiment will be able to operate independent of signals and/or power from the surface, as the optional wireless communication means can allow various forms of signal transmission to or from the surface, for example, transmission of signals to the surface which indicate that the tool is in motion or not, activation signals from the surface, and/or configuration or reconfiguration of the magnetic field detector from the surface.
[0048] According to another embodiment of the present invention, the magnetic field detector communicates with the surface through suitable and per se known cable elements, the power supply either being provided by a battery or being supplied through the cable elements.
[0049] It should be understood that the magnetic field detector according to the present invention either can constitute a compact, small, integrated circuit, or the different elements can be arranged at different points, for example, so that the motion of a tool downhole can be monitored from the surface and so that a configuration and optional reconfiguration of the magnetic field detector can be effected on the surface. Parts of the magnetic field detector may, for example, consist of a computer on the surface, where an indication of the tool's motion is shown on a screen or by means of suitable display instruments, and where parameters which are relevant for a configuration or optional reconfiguration of the magnetic field detector can be adjusted via a suitable user interface.
[0050] As stated, the magnetic field detector according to the present invention may comprise one or more magnetic field sensors. Most magnetic field sensors are 1-dimensional (1D), i.e., that they essentially measure a magnetic field in one direction. If more than one sensor are used, they may be arranged so that they increase the measuring accuracy of the magnetic field detector, i.e., that they are arranged so as to measure a magnetic field in the same direction. Alternatively, the magnetic field sensors can be arranged perpendicular to one another, so as to obtain 2D- or 3D-measurements. According to one preferred embodiment, at least two magnetic field sensors are used that are oriented perpendicular to each other, at least one in an axial direction, and at least one transverse to the axial direction. The magnetic field sensor(s) which is/are oriented in the axial direction will then be able to indicate motion of the tool axially through, for example, a well, the magnetic field sensor(s) oriented transverse to the axial direction then being able to indicate any rotational motion of the tool. It should be understood that other magnetic field sensor configurations are also possible, the application determining what configurations are expedient.
[0051] The magnetic field detector according to the present invention can also be used as an operating control per se. Because the magnetic field detector recognises a predetermined sequence of motion, the magnetic field detector will be able to activate an event or an operation downhole in an oil or gas well. The present invention thus provides an alternative to dropping balls down into the well to start or terminate certain operations. Because the magnetic field detector can both recognise sequences of motions and unequivocally determine that the tool on which it is located has been subjected to a sequence of motions and the motions that are required to perform one or more certain events or operations, the magnetic field detector helps to ensure that the performance of the one or more certain events or operations can immediately be verified from the surface. This helps to save valuable time and prevents unnecessary waiting on the surface. If used as an activator, the magnetic field detector according to the present invention will be able to prevent or start activation on motion or standstill. In connection with such application, there may be a wish to use the magnetic field detector together with other instruments, such as pressure sensors, temperature sensors, skirt detectors, electromechanics, memory, etc.
[0052] The magnetic field detector according to the present invention can be adapted to other areas of use and conditions by changing previously mentioned filters or using other filters that are adapted to the conditions in which the magnetic field detector is located. The adaptation of the magnetic field detector to the intended area of use can easily be obtained by reconfiguring the sensitivity-reducing filters, the buffer elements and/or the self-calibration elements, the reconfiguration largely being performable on the software level. | A method and an apparatus for activating an event if an object has undergone a pattern of motion with alternating motion and standstill which corresponds to a predetermined sequence of motions, in which all forms of motion are included. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to ribbon bows and more particularly to a novel construction of decorative bows and methods of making same.
In the normal manufacture of bows, a strip of ribbon material is folded to produce a number of petals which are held in position by one or more bands. In such construction it is possible to obtain a limited variety in the display of the bands.
The variety and style of ribbon bows made according to conventional techniques as described above are limited and quite often require a series of complicated steps in their manufacture.
Typical bow constructions and methods of making same are shown in U.S. Pat. Nos. 2,105,436 (Flatto), 2,587,502 (McMahon), 2,845,736 (Crawford), 3,283,339 (Heifetz), and 4,339,059 (Kenyon). The preceding patents are representative of the state of the art and none discloses or suggests the present invention.
SUMMARY OF THE PRESENT INVENTION
In the present invention, ribbon bows are made from strips of suitable material such as woven metallic acetate polyester fibers having inherent stresses which cause the strips to curl orthogonally to the lengths of the strips.
In accordance with a preferred embodiment of the invention, a strip of such material is cut into suitable lengths and superimposed on each other in one or more of a variety of ways to obtain a desired effect, and then the nested ribbon strips are folded to obtain a ribbon bow configuration.
The method of preparing the ribbon bows in accordance with this invention is simple, efficient, and economical and produces bows which are suitable for a variety of applications as will be apparent from the description below of preferred embodiments of the invention.
It is thus a principal object of this invention to provide an improved method of producing ribbon bows which is novel in construction and appearance.
Other objects and advantages of this invention will hereinafter become obvious from the following detailed description of preferred embodiments of this invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a roll of material to be used to carry out the principles of this invention.
FIG. 2 is a perspective view of a strip of ribbon material taken from the roll shown in FIG. 1 to be employed in making a bow in accordance with the principles of this invention.
FIG. 3 is a similar view of the opposite side of a strip to be nested in with the strip shown in FIG. 2.
FIG. 4 is a perspective view of the strips of FIGS. 2 and 3 nested together with the convex side of the inner strip facing outwardly.
FIG. 5 is a perspective view of the strips of FIG. 4 being folded.
FIG. 6 is a view similar to that of FIG. 5 with a tie to be employed to form the bow.
FIG. 7 is a front perspective view of the bow being formed with the tie in place.
FIG. 8 is a back perspective view of the bow of FIG. 7 with the tie being tucked ready to be attached.
FIG. 9 is a view of the bow of FIG. 8 with the tie being tacked into place.
FIG. 10 is a perspective view of the bow formed in FIGS. 1-8 in the process of being fanned out.
FIG. 11 is a perspective view of the completed bow with the locations shown where tacking stitches are applied to maintain the fanning out.
FIGS. 12-14 show three strips ready for assembling another embodiment of this invention.
FIG. 15 shows the three strips of FIGS. 12-14 nested with the interior strips having their concave portions extending outwardly.
FIG. 16 is a perspective view of a head band on which a bow made in accordance with this invention is mounted.
FIG. 17 shows such a bow mounted on a comb.
FIG. 18 shows such a bow mounted on a barrette.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The material required for use in making this invention is one in which the material incorporates inherent stresses so that each strip employed in forming the bow tends to form a curl which is parallel to the length of the strip, that is, a curl which is perpendicular to the orthogonal axis of the strip.
Any material having the characteristics described above would be suitable for the present invention. However, the material actually employed for making these bows is commercially available woven acetate polyester fibers containing metallic threads coming off rolls and prior to being heat treated to remove the stresses which come about as a result of the manufacturing process. Normally, such material is heat treated in order to relieve the internal stresses present as the result of the weaving process so that the sheets will remain flat. But, in the present invention, the material is employed prior to the heat treatment so that the stresses remain in order to permit this invention to be practiced as will hereinafter described. One of the advantages of the metal threads employed in the material is that it glitters and enhances the utility of the bow.
Referring to FIG. 1, coming off roll 10 is a sheet of woven metallic acetate polyester material 12 which has just been manufactured but not yet treated to relieve stresses which have been built up during the weaving process, as is understood in the art. This material is commercially available. The strips of material to be used in the making of the bows are cut from the material along the broken lines designated by the numeral 14. While the width and length of the strips cut would depend on the size of the bows to be made as well as which embodiment is to be produced, typically the strips would be 11/2 to 3 inches wide and in the range of about six to 12 inches in length.
As seen in FIG. 2, foundation strip 16 displays its natural or inherent curl along each of the long edges with both curls along opposite edges facing in the same direction. In FIG. 3, a second or nesting strip 18 is shown facing in the opposite direction, that is, the back or convex side of strip 16 being seen. By front of strip herein is meant the concave side of the strip in which the curls are exposed and visible.
To prepare a bow in accordance with a preferred embodiment of this invention, strip 18 is placed inside of strip 16 with the curls of strip 18 facing strip 16, as seen in FIG. 4. Due to the flexible nature of the material involved, the curls are either spread apart (as in the case of strip 16) or pushed together (as in the case of strip 18) or a combination of both to form the assembly shown. As will be seen below in connection with another embodiment of this invention, nesting strip 18 can be reversed, that is, with its front or concave side facing outwardly, that is, in the same direction as strip 16.
As seen in FIG. 5, the assembly shown in FIG. 4 is then folded over toward the flat or rear surface of strip 16, while as seen in FIGS. 6 and 7 a third strip 22 similar to strips 16 and 18 is folded over to crimp the center and tacked together in the back as illustrated in FIGS. 8 and 9, forming the basic configuration of bow 24. In order to complete bow 24, the wing or ends of bow 24 are grasped and spread apart as shown by the double headed arrows in FIG. 10 and tacked at locations 26 to maintain the fanning which is accomplished by the spreading action just described.
In another embodiment of this invention, shown in FIGS. 12 to 15, three strips of material can be employed, using a foundation strip 32 and a pair of nesting strips 34 and 36. In this embodiment, nesting strips 34 and 36 are reversed so that their backs are facing the back of strip 32 so that all the curls will be exposed on the visible side of the bow producing a unique effect. Of course, if desired, nesting strip 36 could be facing toward the back of strip 32.
To complete construction of the bow from the strips shown in FIG. 15, the assembly would be folded back as in the case shown for the embodiment of FIGS. 2-11, and and subsequent steps followed in the manner previously described.
The ribbon bows hereinabove described may be used in a variety of ways. As seen in FIG. 16, bow 24 or any of its other embodiments may be mounted on a headband 38, or as seen in FIG. 17, bow 24 may be mounted on a comb 42, or, as seen in FIG. 18, mounted on a barrette 44.
It is thus seen that there has been provided a unique bow construction and a method for making such a bow. While only certain preferred embodiments of the invention have been described, it is understood that many variations are possible without departing from the principles of this invention as defined in the claims which follow. | A ribbon bow made from nested strips of material having natural curls along the edges thereof folded back and crimped using another strip to form the bow. The method is to nest one or more such strips and then fold them followed by crimping to form the bow. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional application No. 61/168,030, filed Apr. 9, 2009, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to systems and methods for automatically tracking and analyzing educational games and interactive teaching tools.
[0004] 2. Prior Art
[0005] At present, methods for recording and describing the use of educational games, animations and interactive teaching tools make poor use of the technology they depend on: typically, instructors or graduate research assistants make subjective assessments, or record the subjective assessments of users themselves, and then spend long hours verifying and logging the “data”. These practices, being labor-intensive and requiring the presence of a qualified instructor or evaluator at every workstation for every minute of data generation, and subsequent hand entry of data, constrain the capacity of game developers to derive useful information from users, and thereby inform the ongoing game development process. At the same time, instructors are hampered as much as they are helped by computers in the classroom, due to the poor articulation of materials with curricula and the lack of a concomitant system for recording and evaluating the work of students, or measuring their progress.
[0006] While the attraction of computer games for school-age children and young adults is well-recognized, and the hope that this attraction can be leveraged to motivate students to greater participation and achievement (particularly, for example, in science and technology fields) is reasonable, the systems for assessment/evaluation data collection and representation are lagging.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention provides for an integrated system of recording, collection, storage, and representation of individual and aggregate use patterns of a fully-developed matrix of interactive course materials supporting K-16 (Kindergarten through undergraduate) curricula in STEM (Science, Technology, Engineering, and Mathematics) subjects.
[0008] The first level of recording is the “journaling” of individual gameplay sessions on the computer being used by a student in class or at home. This function provides the ability for a teacher to replay the session at a variety of speeds, to assist the teacher in assessing the student's level of engagement, learning style, and specific areas of proficiency or need in relation to the subject matter. The second level of recording is statistical. The computer tabulates statistics about the student's use of the games/teaching modules: number of sessions, length of sessions, number of right and wrong answers sorted by subject area. Each computer may comprise a programmable logic unit, an output device, one or more input devices, and volatile and persistent storage devices.
[0009] In the classroom, data is typically aggregated through the school data network in real time. In the home, data is stored by the student's computer for subsequent downloading to the school's server when the student logs in to the system. Alternatively, an internet accessible secure account can be created to transmit the data to the school computer system either continuously or at the end of the game.
[0010] The system automatically compiles all the desired metrics in a form suitable for use by the teacher in grading and advising individual students, including the provision of information graphics to help assess individual achievement and progress over the course of a semester or a school year.
[0011] At the curriculum and learning level, the system will assist instructors in identifying the strong and weak areas in each student's knowledge even across various courses taken in different years. The knowledge deficiencies can be backtracked to their origin and resources can be committed in a specific and targeted manner.
[0012] At the school level, the system provides data to assess student achievement and progress over the course of a student career, and across subjects. This provides, at negligible cost of time or extra overhead, a richly detailed and reliable set of evaluation and assessment tools for students and teachers.
[0013] At the school board level, the system provides valuable, reliable, and complete metrics for the performance of individual schools in STEM subjects over time, to help assess, evaluate, and improve practices where needed, or to help identify particularly successful schools, whose implementation can be studied more closely as a model for their peers.
[0014] At the curriculum development level, the system assists subject matter experts and educational game designers in developing and improving the teaching tools, and the curriculum itself. The integration of STEM subjects across educational levels makes it possible to greatly improve the articulation between middle and high school, and between high school and college, two transitions which have been difficult to design for up to this point.
[0015] At the level of general issues in computing for the classroom, the system provides a valuable non-invasive resource for research and development in the academic, public education, and private sectors.
[0016] Other features, aspects, and advantages of the invention will become apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 a is a flow diagram of the evaluation, assessment, and development cycle in one embodiment of the invention.
[0018] FIG. 1 b is a curriculum matrix in one embodiment of the invention.
[0019] FIG. 2 is a flow diagram of an in-class student session in one embodiment of the invention.
[0020] FIG. 3 is a flow diagram of a homework or informal student session in one embodiment of the invention.
[0021] FIG. 4 a is a diagram of a system in one embodiment of the invention which includes a student classroom.
[0022] FIG. 4 b is a diagram of a system in one embodiment of the invention which includes a student's home.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] FIG. 1 a is a flow diagram of the evaluation, assessment, and development cycle, showing the method in one embodiment of the invention. Item 1 a . 1 details the lesson for a particular subject and level. A lesson will contain a game 1 a . 1 . 1 , media 1 a . 1 . 2 , and text 1 a . 1 . 3 . FIG. 1 b shows a curriculum matrix with lessons distributed across a plurality of subjects, with each subject having multiple difficulty levels.
[0024] At step 1 a . 2 , an instructor gives an in-class lecture or demonstration to the students. Such a lecture or demonstration may incorporate the game 1 a . 1 . 1 , media 1 a . 1 . 2 , and text 1 a . 1 . 3 of the lesson 1 a . 1 .
[0025] After completion of the lecture or demonstration, the student may participate in an in-class student session (step 1 a . 3 ). FIG. 2 shows a detailed flow diagram of an in-class student session 1 a . 3 .
[0026] At step 2 . 1 ( FIG. 2 ), the student may repeat the demonstration on the individual classroom computer 4 . 3 . 1 , 4 . 3 . 3 ( FIG. 4 a ). This will help if the student did not understand something during the first lecture or demonstration (step 1 a . 2 ).
[0027] At step 2 . 2 , the student begins playing the educational game. The game is designed to teach the lesson to the student and test the student's knowledge. After completing a game, the student may move horizontally across the curriculum matrix ( FIG. 1 b ) from one subject to another at the same level of difficulty (step 2 . 3 ). This provides comparative data for analysis of how the student performed in a different subject at the same level of difficulty.
[0028] Alternatively, the student may move vertically up and down the curriculum matrix ( FIG. 1 b ) from one level to another in the same subject (step 2 . 4 ). This provides comparative data for analysis of how the student performed in the same subject at a different level of difficulty. In addition, this scheme can be used to test the student's ability to apply a given concept in two different fields.
[0029] After playing the games (step 2 . 2 ), the student may finish the gameplay session (step 2 . 5 ) and review the results in a game replay session (step 2 . 6 ). The game replay session (step 2 . 6 ) will allow the student to review the gameplay session that was just completed and review the performance statistics of the gameplay session. Such a review of the gameplay session allows the student to determine the strengths and weaknesses in the subject matter studied.
[0030] After reviewing the gameplay session in step 2 . 6 , the gameplay session and gameplay session statistics are stored on the local cache 4 . 3 . 5 of the student's computer 4 . 3 . 1 , 4 . 3 . 3 ( FIG. 4 a ) in step 2 . 7 . This will permit the student to review the gameplay sessions in the future.
[0031] The gameplay session and gameplay session statistics are also uploaded to the school's database 4 . 2 . 1 ( FIG. 4 a ) and the BLM master database 4 . 1 . 1 ( FIG. 4 a ). After completing the in-class gameplay session (step 2 . 5 ), the student may also play the game at home or in an informal student session ( FIG. 3 ).
[0032] Returning to FIG. 1 a , the student may proceed to a homework or informal student session (step 1 a . 4 ) following the in-class lecture (step 1 a . 2 ). Alternatively, the student may proceed to a homework session (step 1 a . 4 ) following the in-class student session (step 1 a . 3 ).
[0033] FIG. 3 shows a detailed flow diagram of a homework or informal student session (step 1 a . 4 ). At step 3 . 1 , the student may play the game for the chosen lesson. The student may move horizontally across the curriculum matrix ( FIG. 1 b ) in different subjects at step 3 . 2 . Alternatively, the student may move vertically up and down the curriculum matrix ( FIG. 1 b ) to different levels of the same subject in step 3 . 3 .
[0034] After completing the gameplay session at step 3 . 4 , the gameplay session and statistics are stored in the local cache 4 . 3 . 5 ( FIG. 4 b ) of the student's computer(s) 4 . 3 . 1 , 4 . 3 . 4 ( FIG. 4 b ). At step 3 . 5 , the student can review the gameplay session that was just completed and review the performance statistics of the gameplay session.
[0035] Alternatively, after completing the home gameplay session (step 3 . 4 ), the system will store the gameplay session and statistics. If the student has a network connection, then the gameplay session and statistics will be immediately uploaded to the school's master database 4 . 2 . 1 ( FIG. 4 b ) and the BLM master database 4 . 1 . 1 ( FIG. 4 b ). If the student has no network connection, then the gameplay session and statistics will, at step 3 . 6 , be saved in the local cache 4 . 3 . 5 ( FIG. 4 b ) for later uploading to the school's master database 4 . 2 . 1 ( FIG. 4 b ) and the BLM master database 4 . 1 . 1 ( FIG. 4 b ).
[0036] Returning to FIG. 1 a , the results of the gameplay sessions of the in-class student session (step 1 a . 3 ) or the homework session (step 1 a . 4 ) will be stored as raw session records 1 a . 5 that can be stored in a data warehouse 1 a . 10 . Such a data warehouse 1 a . 10 can be the school database 4 . 2 . 1 ( FIGS. 4 a and 4 b ) or the BLM master database 4 . 1 . 1 ( FIGS. 4 a and 4 b ), for example.
[0037] From the raw session records 1 a . 5 , the system can generate usage and scoring data 1 a . 6 . Such usage and scoring data 1 a . 6 can be tailored for use by teachers 1 a . 7 , the school 1 a . 8 , and the school board 1 a . 9 , among others. Teachers, schools, administrators, statisticians, and others can utilize the session records stored in data warehouse 1 a . 10 to conduct data analysis (step 1 a . 11 ) to determine the effectiveness of the curriculum and assess how students are learning across multiple subjects and levels of the curriculum.
[0038] At step 1 a . 12 , curriculum designers, teachers, administrators, and others can evaluate the effectiveness of the curriculum and decide what improvements need to be made to the curriculum in order to facilitate learning by the students. Such improvements can involve improving the design of the game itself at step 1 a . 13 so that students are better able to learn by using the game. The improvements can also involve improving the curriculum design (such as the text 1 a . 1 . 3 and media 1 a . 1 . 2 ) of the lessons at step 1 a . 14 .
[0039] Accordingly, while the invention has been described with reference to the structures and processes disclosed, it is not confined to the details set forth, but is intended to cover such modifications or changes as may fall within the scope of the following claims. | An integrated system and method for the recording, collection, storage, and representation of individual and aggregate use patterns of a fully-developed matrix of interactive course materials supporting K-16 curricula in STEM (Science, Technology, Engineering, and Mathematics) subjects. Students may utilize interactive educational games to assess their performance across multiple subjects and difficulty levels of a curriculum, and obtain feedback and statistics regarding their progress in attaining educational goals. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle wheel attachment dynamically operable to compensate for wheel imbalance.
2. Description of the Prior Art
Various forces acting upon a tire tend to cause wheel imbalance, particularly generally upwardly directed forces produced by road imperfections and bumps. The resulting tire bounce reduces the traction or "footprint" of the tire, causing rider discomfort, increased tire wear, less efficient transfer of propulsive torque from the tire to the road, and changes in wheel angular velocity. There is a consequent loss of fuel economy, impaired vehicle stability, and reduced braking efficiency. Other harmful effects of tire bounce are a reduced ability of the wheel to steer or track in a straight line, poorer traction in snow and ice, a greater tendency to hydroplane in rainy weather, and accelerated deterioration in vehicle front end alignment.
Road hazards typically also produce a lateral force vector which acts against the tire side and tends to prevent proper wheel tracking.
Even in instances in which a road is relatively smooth, forces are inherent in the rolling of a tire which produce wheel imbalance. In this regard, usual balancing of a wheel is done either by taking it off the vehicle and arranging it upon or spinning it in a balancing device, or by hoisting the vehicle and spinning the wheel in place. Small weights are placed on the wheel according to the imbalances detected.
However, when a vehicle is on the road each tire is characteristically slightly flattened or deformed by the weight of the vehicle and the center of gyration of the wheel is no longer coincident with the axis of wheel rotation. This off-center relation introduces a vibration or wheel bounce characterized by the same undesirable consequences as the wheel bounce caused by road irregularities.
Certain wheel covers of the prior art, such as those described in U.S. Pat. No. 3,312,505, issued Apr. 4, 1967 for "Wheel Cover," and in U.S. Pat. No. 4,178,041, issued to me on Dec. 11, 1979 for "Wheel Attached Balancing Device," are made relatively heavy to increase the angular momentum of the wheels to which they are mounted. This has the desirable effect of providing greater resistance to forces tending to change the angular momentum. There is a smaller angular deviation of the wheel axis for any applied force. This has a desirable gyroscopic effect in reducing the adverse consequences of side loads on the tire. However, there is an insufficient compensation for certain other types of wheel imbalance.
In this regard, the wheel covers of the aforementioned patents include a central hub structure and radially extending spokes or sectors arranged to project axially in a shallow conical configuration. This conical configuration tends to flatten into a vertical plane when the associated wheel is rotating at relatively high speeds. as the flattening occurs the sectors pass outwardly against a trim ring mounted to the vehicle wheel. The cover is designed so that movement of the hub structure is directly translated into radial forces upon the sectors. This was intended to aid in holding the trim ring in place upon the wheel, and also was intended to load certain portions of the rim differentially, depending upon the stress being experienced by the associated sectors. This was supposed to reduce vibratory motion occurring from an unbalanced condition of the wheel. Neither of these objectives was satisfactorily accomplished.
SUMMARY OF THE INVENTION
According to the present invention, an imbalance compensating vehicle wheel attachment, preferably in the form of a decorative wheel cover, is provided which is deliberately designed to enable relatively free radial movement of a hub structure relative to a plurality of spokes or sectors extending radially from the hub structure. The radially outward extremities of the sectors are resiliently coupled to a surrounding rim structure which is attachable to the vehicle wheel, the resilience of the coupling tending to bias the sectors radially inwardly in opposition to forces, including centrifugal forces, which tend to move the sectors radially outwardly.
With this arrangement, the centers of mass or gravity of the hub structure and each of the sectors is adapted to change dynamically in response to road shocks and tire rolling action, and furthermore, to change in a manner which it has been found establishes an instantaneous radius of gyration which tends to compensate for dynamically occurring wheel imbalances.
In a preferred embodmient, the radially inwardly located extremities of the sectors are provided with enlarged openings through which project studs carried by the hub structure. Nuts snugly tightened upon the studs hold the sectors in position, but the nuts are not tight enough to prevent relatively easy relative movement between the hub structure and the individual sectors.
Use of the present vehicle wheel attachment has been found to compensate for wheel imbalance. In addition, it has been found that such compensation is accompanied by a surprising improvement in fuel economy. The reduced tire bounce, better traction and increased vehicle stability appear to be very closely related to the surprising increase in vehicle miles traveled per gallon of fuel.
Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view of the present vehicle wheel attachment;
FIG. 2 is an enlarged view taken along the lines 2--2 of FIG. 1;
FIG. 3 is an enlarged view taken along the line 3--3 of FIG. 1;
FIG. 4 is an exploded perspective view of portions of adjacent sectors and the trim ring, particularly illustrating a gripper element;
FIG. 5 is an enlarged view taken along the line 5--5 of FIG. 1;
FIG. 6 is a partially diagrammatic view of certain of the wheel attachment components in their static condition, the upper third of the figure showing a cross section of the inner extremity of a sector and the interconnecting fastener; the middle third of the figure showing the inner extremity of the sector in elevation, with the fastener shown in cross-section; and the lower third of the figure showing a cross-section of portions of the trim ring and outer extremity of the sector;
FIG. 7 is a showing similar to that of FIG. 6, but with the components in their dynamic state, as they would appear when the vehicle is in motion; and
FIG. 8 is a showing similar to that of FIG. 7, but illustrating the components upon engagement of a road obstacle by the tire.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and particularly to FIGS. 1 through 5, there is illustrated a wheel attachment device or cover 10 according to the present invention and comprising, generally, a rim structure or trim ring 12 adapted for mounting to the tire rim 14 of a vehicle wheel 15; a hub structure 16 located centrally of the trim ring 12 and adapted for axial alignment of its center of gravity with the center of gravity and axis of rotation of the wheel 15; a plurality of generally triangularly shaped spokes or sectors 18 uniformly circumferentially arranged about and radiating outwardly from the hub structure 16, the radially outwardly located extremities of the sectors 18 being resiliently coupled, as will be seen, to the trim ring 12; and a plurality of mounting means, each comprising a nut 20 and a bolt 22, coupling the radially inwardly located extremities of the sectors 18 to the hub structure 16.
The vehicle wheel 15 is typical of vehicle wheels having a plurality of openings to receive threaded bolts 24 by which the wheel 15 is attachable by lug nuts 26 in position adjacent the vehicle axle hub.
The tire rim 14 of wheel 15 includes a circumferential main flange 28 having an outer face for seating a usual and conventional tubeless tire 30.
The outer extremity of the main flange 28 is extended radially outward to form a bead flange 32 for constraining the tire 30 against lateral separation from the wheel, as illustrated in FIG. 2. The radially outward extremity of the bead flange 32 is curved axially outwardly to form a short flange or lip 34 which tends to follow the contour of the tire. The lip 34 is typically utilized as an attachment flange for the usual fastening clips of small balancing weights (not shown) used in conventional tire balancing systems. However, it is used for a different purpose in the present device, as will be seen.
The trim ring 12 is preferably made of steel and comprises an annular band having a circumferential main flange 36 whose diameter is less than the diameter of the inner surface of the tire main flange 28 to define an annular space 29 therebetween.
The outer extremity of the trim ring main flange 36 is radially outwardly formed to provide a bead flange 38 which rests against the wheel bead flange 32. A plurality of generally U-shaped fasteners or clips, one of which is illustrated at 40 in FIG. 2, are utilized to insure that the trim ring bead flange 38 is held in position against the wheel bead flange 32. The clips are made of spring material such that engagement of the opposed legs of each clip on the respective bead flanges 32 and 38 securely holds the trim ring 12 in position upon the wheel. The plurality of clips 40 are generally equally circumferentially spaced about the periphery of the trim ring bead flange 38.
As best seen in FIGS. 3 through 5, in the area adjacent the radial joint between each pair of sectors 18, the trim ring main flange 38 is characterized by a pair of circumferentially spaced apart openings 42, one on each side of the joint defined between the adjacent side extremities of each pair of sectors 18.
A gripper member 44 of U-shape is located adjacent each pair of openings 42 for engagement with the tire rim main flange 28 through the openings 42. Each gripper member 44 is made of relatively heavy gauge, high grade spring steel and its base 46 is attached by a pair of rivets, one of which is shown at 50 in FIG. 3, to the inner surface of the trim ring bead flange 38. The opposite legs 48 of the gripper member extend through the openings 40 and are characterized by sharp points directed radially and outwardly. The clearance between the trim ring flange 36 and the tire rim flange 52, and the resilient bowing of the gripper base 46, enables the trim ring to be pressed axially inwardly to mount it to the wheel 15 as illustrated. When this is done, the sides of the points of the gripper legs 48 scrape across the flange 28, but opposite or axially outward movement of the trim ring 12 is prevented because the points dig into the metal of the flange 28. As will be seen, the sectors 18 are urged outwardly by centrifugal and other forces and exert extraordinary forces on the gripper points to maintain the wheel cover 10 in mounted position. The use of the clips 40 is an extra or backup arrangement to make certain that the cover 10 cannot come off in normal operation.
As best seen in FIGS. 4 and 5, the radially outwardly located extremities of each sector 18 are axially inwardly formed to define a resilient bias flange 52 characterized by a pair of inwardly directed, circumferentially spaced-apart recesses or seats 54 whose concave undersides closely receive complemental recesses or seats 56 formed in the trim ring 36. Although it is contemplated that this arrangement will provide sufficient integrity of connection between the sectors 18 and the trim ring 12 to hold the sectors in position during operation of the wheel cover 10, the seats 54 and 56 are preferably spot-welded together.
The radially inwardly located extremity of each sector 18 includes an enlarged circular opening 58, as best seen in FIGS. 6 through 8. The considerably smaller diameter threaded bolt or stud 22 projects through the opening 58. The studs 22 for the various sectors 18 are circumferentially arranged upon and rigidly attached by welding or the like to a generally vertically oriented annular backplate 62 which forms a part of the hub structure 16.
A resilient fibrous washer 64 is mounted on each stud 22 between the plate 62 and the sector 18, and a similar washer 66 is mounted on the stud between the sector 18 and the nut 20. The nuts 20 are tightened upon the studs 22 snugly but not tightly to secure the sectors 18 to the backplate 62. In one satisfactory embodiment, each nut 20 is tightened upon its associated stud 22 at approximately 50 pounds of torque. A separable dome 70 is integral with each nut 22, and is preferably dimensioned to separate or pop off the remainder of the nut 22 if the tightening torque exceeds the preferred 50 pounds. If the torque exceeds this value, the associated stud 22 engages and forces the dome 70 off the nut 20.
Each sector 18 includes a ventilating opening 72 in its vertical face to provide adequate cooling of the adjacent vehicle brakes. In addition, the openings 72 allow access to the usual tire inflation valve (not shown) in five different circumferential positions of the cover 10 relative to the vehicle wheel 15.
The bias flange 52 and trim ring main flange 36 include cutouts 74, as seen in FIG. 5, through which the tire valve can project. In addition, as seen in FIG. 4, the corners of the adjacent bias flanges 52 of each pair of sectors 18 are cut away to provide a rectangular opening 76 in alignment with the midportion or base 46 of the associated gripper member 44. This provides clearance between the base 46 of each gripper and the associated pair of sectors 18. However, the outer corners of the pair of sector 18 defining the opposite ends of each opening 76 rest upon the gripper member 44 above the legs 48. With this arrangement the sectors 18 exert a relatively great force upon the legs 48, as previously mentioned, when the sectors 18 move radially outwardly under the influence of centrifugal and other forces.
The sectors 18 are preferably made of relatively heavy gauge steel, in the order of 0.048 inches in wall thickness. The hub structure 16 is also made of heavy gauge steel, preferably twice the wall thickness of sector 18, such that the sectors 18 and the hub structure 16 weigh approximately three and two pounds, respectively, for a 13 inch diameter vehicle wheel.
The hub structure 16 is characterized by an axially outwardly projecting dome or hub 78 which may be decorated or otherwise ornamentally configured for aesthetic purposes.
The wheel cover 10 is mounted to the wheel 15 by forcibly pressing the cover axially inwardly until the trim ring bead flange 38 bears up against the wheel bead flange 32, as seen in FIG. 2. The clips 40 are then placed in position to ensure that the cover 10 will remain in position at all speeds and despite heavy road shocks.
As will be apparent from FIG. 2, the hub structure 16 is located centrally of the wheel 15 for static axial alignment of its center of gravity with the center of gravity and axis of rotation of the wheel and tire combination.
In the mounted position of the cover 10, the points of the gripper legs 48 engage the wheel main flange 28 to aid in maintaining the cover 10 in mounted position.
The general vertical orientation of the cover 10 provides optimum angular momentum to the wheel 15, as will be apparent.
As will be seen, it is important for the studs 22 to be relatively freely movable relative to the margins defining the openings 58. In this regard, it is theorized that, as seen in FIG. 6, with the vehicle at rest the studs 22 are located in the radially outward portions of the openings 58. This is for the reason that the sectors 18, in a static condition, are biased radially inwardly by the flanges 52, which are cantilever mounted at the seats 54.
When the vehicle is moving at a significant speed, such as at least 10 or 15 miles per hour, the centrifugal force imparted to the sectors 18 causes each sector 18 to move radially outwardly under the influence of centrifugal force so that its flange 52 is biased radially outwardly, and the stud 22 is then located in approximately the radially inward portion of the opening 58, as seen in FIG. 7.
On encountering a road bump, for example, the sector or sectors 18 closest to the bump are relatively forcibly urged radially outwardly against the bias of their flanges 52, as seen in FIG. 8. There is a corresponding radially outward movement of the studs 22 of those sectors until they are located adjacent the radially outward portion of the opening 60, as seen in FIG. 8. It is theorized that the stud 22 of the sector 18 closest to the bump experiences the greatest relative movement, and that the studs 22 of the sectors 18 on either side also experience this relative movement, but to a lesser extent.
The relative movement between the sectors 18 and the studs 22 of the hub structure 16 is permitted by virtue of the lack of complete tightening of the nuts 20, as previously described, and by virtue of the presence of the fibrous washers 64 and 66, which are characterized by a lower coefficient of friction than metal. The described movement of each particular sector 18 is substantially independent of the other sectors 18. However, it should be understood that the other sectors 18 are also undergoing relative movement, the extent and direction of such movement depending upon their positions relative to the point of engagement between the tire and the road surface, and relative to the location of any other unbalancing forces upon the wheel and tire combination.
Although the foregoing description of the condition of the components in FIG. 8 has been made in conjunction with impact of the tire against a road bump, the same phenomenon is believed to occur as each sector rotates into adjacency with the road surface.
It is believed that as a tire rotates into contact with the road surface, the resistance of that road surface to the tire tends to change the angular momentum of the tire and develops a deformation or outward bulge in the tire, something like the bow wave which develops at the bow of a ship passing through the water. This outward bulge is also like a road bump over which the tire must roll, and the same action of the wheel cover to compensate for imbalances generated by a road bump takes place to compensate for the tire deformation or bulge. That is, the radially extended sectors 18 adjacent the tire bulge, and the radially adjusted position of the hub structure 16, develop an instantaneous change in the center of gyration of the total mass that tends to thrust in the general direction of the deformation or bulge, helping to flatten or flex the tire as its rotation continues, and thereby reducing rolling resistance.
The exact theory of operation is unknown and applicant offers the foregoing for possible assistance to those skilled in the art. Whether or not a device comes within the scope of applicant's invention is to be determined by the scope of the appended claims, and not by whether or not such devices operate according to the foregoing theory or theories. What is known is that the described structure of the wheel cover 10 provides a surprising improvement in fuel economy.
Similary, FIGS. 6 through 8 are intended to illustrate how the cover components are adapted to move continuously, and how such dynamic movement is believed to establish instantaneous adjustments or changes in the radius of gyration to compensate for changes in the locations of the centers of gravity of the masses of the cover components, and to compensate for changes in the magnitude and character of the forces which develop against the tire and wheel as the tire encounters road bumps, and as it continually bulges adjacent the road surface, flexes and then flattens.
From the foregoing, it is seen that a wheel cover has been provided which is operative to establish a radius of gyration to compensate for the changed location of the center of gravity and center of gyration of the tire/wheel combination attendant flexing of a tire over a road surface, and to a greater extent, to compensate for tire bounce from road bumps. As previously indicated, the center of gyration is adjusted downwardly toward the road surface to provide an additional force or better "footprint" of the tire against the road surface, and to reduce upward acceleration of the tire. The consequent more continuous and firmer tire traction is apparently responsible for much of the increase in vehicle fuel economy.
Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention. | An imbalance compensating vehicle wheel attachment having a rim structure for mounting to a vehicle wheel, and further having a plurality of spokes or sectors coupled to the rim structure and extending radially inwardly to a hub structure. A mounting arrangement is provided to couple the inward extremities of the sectors to the hub structure to enable radial slidable movement of the sectors relative to the hub structure whereby the masses of the hub structure and sectors are dynamically movable to establish a radius of gyration tending to compensate for any wheel imbalance. | 6 |
FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for ground working and, in particular, for use in grooming ditches.
BACKGROUND OF THE INVENTION
Canadian patent 1,201,287 discloses an apparatus for ,grooming roadside ditches entitled “Ditcher Head Assembly for Cleaning Ditches”. The ditcher head assembly is a rotating head that can be mounted on a tractor to throw debris from a ditch onto a shoulder of a road.
Canadian patent 1,080,257 discloses an apparatus for grooming ditches entitled “Automated Machinery to Clean Debris from Roadside Ditches, Collect it, and then Transport the Debris to a Major Collection Area for Disposal”. This automated machinery includes a self-dumping truck or trailer in which the debris is collected.
SUMMARY OF THE INVENTION
What is required is an alternate method and apparatus for ground working.
According to one aspect of the present invention there is provided an apparatus for ground working, which includes a chassis and at least three telescopically extendible wheel supports secured to the chassis. At least one support wheel is rotatably mounted to a remote end of each of the telescopically extendible wheel supports. The telescopically extendible wheel supports providing a means whereby the height and angular orientation of the chassis is adjustable to suit a contour of a ditch. A rotatably mounted drum is secured to and underlies the chassis.
The apparatus, as described above, is capable of moving along a road with either one wheel up on the road and two wheels in the ditch or two wheels up on the road and one wheel in the ditch. The telescopic wheel supports permit the height and angular of the chassis to be adjusted to provide sufficient clearance for the drum to operate. A three wheel vehicle is preferred, as there is more space between the wheels to broadcast gravel, as will hereinafter further described.
Although beneficial results may be obtained through the use of the apparatus, as described above, a chassis with a wide enough stance to be stable in a ditch will be too wide to drive down a highway or transport by flat bed trailer. Even more beneficial results may, therefore, be obtained when the chassis includes telescopically adjustable members extending between the at least three wheel supports. This permits the distance between the support wheels to be adjusted to provide for a transport mode.
Although beneficial results may be obtained through the use of the apparatus, as described above, it is difficult to configure a drive or steering system for such a vehicle. Even more beneficial results may, therefore, be obtained when the support wheel on each of the wheel supports has an individual drive motor, and preferably, independent steering.
Although beneficial results may be obtained through the use of the apparatus, as described above, in order to broadcast gravel in a desired direction onto the road, it is preferred that the drum is angularly adjustable. The preferred form of drum having radially projecting teeth.
According to another aspect of the present invention there is provided a method for ground working. A first step involves providing an apparatus for ground working, as described above, with telescopically extendible wheel supports which permit the height and angular orientation of the chassis to be adjusted to suit a contour of a ditch. A second step involves positioning the apparatus with at least one support wheel in a ditch. A third step involves driving along the ditch broadcasting gravel from the ditch onto the road with the drum.
On a gravel road, traffic tends, over time, to move gravel to the shoulders of the road. This gravel is eventually pushed over the shoulders and into the ditch. Over time, a considerable amount of gravel accumulates in the ditch. Instead of hauling in replacement gravel from a remote site, the teaching of the present invention is to reclaim gravel from the ditch and broadcast the gravel back onto the road.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, wherein:
FIG. 1 is an end elevation view, in section, of a freshly gravel road.
FIG. 2 is an end elevation view, in section of the gravel road illustrated in FIG. 1, after prolonged use by vehicular traffic.
FIG. 3 is a top plan view of an apparatus for ground working constructed in accordance with the teachings of the present invention in an operative mode.
FIG. 4 is a front elevation view of the ground working apparatus illustrated in FIG. 3 .
FIG. 5 is a front elevation view of the ground working apparatus illustrated in FIG. 4, being used to groom a ditch in a first angular orientation.
FIG. 6 is a front elevation view of the ground working apparatus illustrated in FIG. 4, being used to groom a ditch in a second angular orientation.
FIG. 7 is a top plan view of the ground working apparatus illustrated in FIG. 3, in a transport mode.
FIG. 8 is a front elevation view, in section, of one of the support wheels from the ground working apparatus illustrated in FIG. 3 .
FIG. 9 is a front elevation view, in section, of another of the support wheels from the ground working apparatus illustrated in FIG. 3 .
FIG. 10 is a top plan view of one of the support wheels from the ground working apparatus illustrated in FIG. 3, showing a steering control assembly.
FIG. 11 is a front elevation view of the ground working apparatus illustrated in FIGS. 4 and 5, with cab elevated.
FIG. 12 is a top plan view of the ground working apparatus illustrated in FIG. 3, with alternative means for adjusting the length of the second telescopic member.
FIG. 13 is a front elevation view, in section, of one of the support wheels from the ground. working apparatus illustrated in FIG. 3 .
FIG. 14 is a top plan view of a steering control assembly for the support wheels of the ground working apparatus, which provides a first alternative to the steering control assembly illustrated in FIG. 10 .
FIG. 15 is a top plan view of a steering control assembly for the support wheels of the ground working apparatus, which provides a second alternative to the steering control assembly illustrated in FIG. 10 .
FIG. 16 is a side elevation view of a working assembly for the ground working apparatus illustrated in FIG. 3 .
FIG. 17 is a detailed side elevation view of a drum orientation mechanism for the working assembly of the ground working apparatus illustrated in FIG. 16 .
FIG. 18 is a detailed side elevation view of a cap elevation mechanism for the working assembly of the ground working apparatus illustrated in FIG. 16 .
FIG. 19 is a detailed end elevation view of underlying support wheels for the working assembly of the ground working apparatus illustrated in FIG. 16 .
FIG. 20 is a perspective view of the underlying support wheel for the working assembly of the ground working apparatus illustrated in FIG. 16 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, an apparatus for ground working generally identified by reference numeral 10 , will now be described with reference to FIGS. 1 through 20.
Referring to FIG. 3, apparatus 10 has a chassis 12 which is substantially triangular shape. Chassis 12 includes a main body 90 , a first telescopically adjustable member 16 and a second telescopically adjustable member 116 . Main body 90 has a first end 13 , a second end 15 . Chassis 12 has a base 17 defined by main body 90 and a movable apex 19 . Moving of movable apex 19 permits apparatus to assume an operating position illustrated in FIG. 3 or a transport position illustrated in FIG. 7 . Main body of chassis 12 has wheel supports 14 secured at first end 13 and second end 15 . A further wheel support 114 is positioned at and forms part of movable apex 19 . As can been seen by referring to FIGS. 4 and 5, and will be hereinafter further described, wheel supports 14 and 114 are telescopically extendible. A support wheel 18 is rotatably mounted to a remote end 20 of each of telescopically extendible wheel supports 14 and 114 . First telescopically adjustable member 16 has a first end 88 and a second end 89 . When apparatus 10 is in the operating position illustrated in FIG. 3, first end 88 of first telescopically adjustable member 16 is pivotally secured to first end 13 of main body 90 and second end 89 is detachably pivotally secured to wheel support 114 at movable apex 19 of chassis 12 . When apparatus is in the transport position illustrated in FIG. 7, second end 89 of first telescopically adjustable member 16 is detached from wheel support 114 and is swung against main body 90 . Referring to FIG. 3, second telescopically adjustable member 116 has a first end 82 and a second end 83 . First end 82 of second telescopically adjustable member 116 is pivotally secured to second end 15 of main body 90 and second end 83 is pivotally secured to wheel support 114 at movable apex 19 of chassis 12 .
Referring to FIG. 3, a length of each of first telescopically adjustable member 16 is controlled to assume a variety of operative position spacings. Movement of first telescopically adjustable member 16 serves to alter the distance between wheel support 14 at first end 13 of main body 90 and wheel support 114 at movable apex 19 of chassis 12 . There are two ways telescopically adjustable member 16 may be extended. The manner illustrated is by a hydraulic piston 92 . When each support wheel 18 at movable apex 19 has a drive motor and a steering motor 24 , as will hereinafter be further described, the same result can be obtained by driving wheel support 114 at apex 19 ahead while steering support wheel 18 until wheel support 114 assumes the desired configuration. Bolts can then be inserted to maintain first telescopic member 16 in the desired telescopic position.
A length of second telescopically adjustable member 116 is maintained constant when in the operating position, but is extended to assume the transport position, as will hereinafter be further described in relation to FIG. 7 . Movement of second telescopically adjustable member 116 serves to alter the distance between wheel support 14 at second end 15 of main body 90 and wheel support 114 at movable apex 19 of chassis 12 .
Referring to FIG. 8, there is illustrated wheel support 14 and a pivotal connection 81 between first end 88 of first telescopically adjustable member 16 and first end 13 of main body 90 . Pivotal connection 81 includes a pivot pin 86 which extends through an aperture 80 at first end 88 of first telescopically adjustable member 16 and then into a pivot pin receptacle 84 . The pivotal connection between first end 82 of second telescopically adjustable-member 116 and second end of main body 15 could be made identical to that illustrated in FIG. 8, and it was originally intended that this be the case. During the course of construction of the proto-type unit, it was determined that having the pivot point too close to main body 90 restricted the ability to pivot to the transport position. Addressing this need resulted in some differences. Referring to FIG. 13, there is illustrated wheel support 14 and a pivotal connection 85 between first end 82 of second telescopically adjustable member 116 and second end 15 of main body 90 . Pivotal connection 85 includes a pivot pin 86 which extends through an aperture 80 at first end 82 of second telescopically adjustable member and then into a pivot pin receptacle 84 . This configuration differs from that illustrated in FIG. 8, as a horizontal extension 187 was added to move pivotal connection 85 away from main body 90 . It was determined that this difference lead to better performance when pivoting into the transport position. It also provided for more clearance space for hydraulic components mounted in the area.
Referring to FIG. 9, there is illustrated movable apex 19 which includes wheel support 114 . Second end 89 of first telescopically adjustable member 16 and second end 83 of second telescopically adjustable member 116 are both secured to wheel support 114 . A pivotal connection 87 between second end 89 of first telescopically adjustable member 16 is illustrated. Pivotal connection 87 includes a pivot pin 86 which extends through an aperture 80 at second end 89 of first telescopically adjustable member 16 and then into a pivot pin receptacle 84 . A pivotal connection between second end 83 of second telescopically adjustable member 116 and wheel support 114 is not illustrated, but is identical to that illustrated in FIG. 9 .
Referring to FIG. 3, first and second telescopically adjustable members 16 , 116 provide several operative positions with wheel support 114 on movable apex 19 spaced in different relationships to main body 90 and wheel supports 14 . Referring to FIG. 7, first and second telescopically adjustable members 16 , 116 provide a transport position in which wheel support 114 on movable apex 19 of chassis 12 is more closely spaced to main body 90 . To adjust apparatus 10 into the transport position, pivot pin 86 is removed to release second end 89 of first telescopically adjustable member 16 . First telescopically adjustable member 16 is then be pivoted to a position parallel to main body 90 . Second telescopically adjustable member 116 is then extended by moving main body forward while applying the brakes to wheel 18 that is mounted on wheel support 114 of movable apex 19 . As main body 90 moves forward, second telescopically adjustable member 116 pivots at first end 82 about pivotal connection 85 to move apex 19 closer to main body 90 .
Referring to FIG. 10, each support wheel 18 has a drive motor 22 to rotate support wheel 18 in either a forward or reverse direction. Each support wheel 18 also has a steering motor 24 that powers a rack and pinion system 25 in either of a forward or a reverse direction to independently steer said support wheel 18 . Each support wheel 18 is rotatable about a longitudinal axis of the corresponding wheel support 14 or 114 , as illustrated by a first position indicated by solid lines 27 and a second position indicated by dashed lines 29 . During the course of developing the proto-type, two alternative steering systems were developed, as illustrated in FIGS. 14 and 15. Referring to FIG. 14, a pair of hydraulic cylinders 124 and 125 were substituted for steering motor 24 and rack and pinion system 25 . Hydraulic cylinders 124 and 125 were attached to opposed sides of a wheel support column 126 . Upon hydraulic cylinder 124 being expanded and hydraulic cylinder 125 being contracted wheel support column 126 rotates to turn wheel 18 in a first direction. Conversely, upon hydraulic cylinder 125 being expanded and hydraulic cylinder 124 being contracted, wheel support column 126 rotates to turn wheel 18 in a second direction. This steering system was found to be effective, although the steering radius was necessarily limited by the stroke of hydraulic cylinders 124 and 125 . It was determined that hydraulic cylinders 124 and 125 provided a 60 degree range of rotation; 30 degrees of rotation in either of the first direction or the second direction. This range of motion was found to be satisfactory for support wheels 18 at first end 13 and second end 15 of main body 90 , but insufficient for support wheel 18 at apex 19 . Referring to FIG. 15, a second alternative was developed-for use on support wheel 18 at apex. This alternative used a steering motor 222 with a steering gear 225 mounted on wheel. support column 226 . The steering motor 222 was linked to steering gear 225 by a chain linkage 224 . This alternative provided a 160 degree range of rotation; 80 degrees of rotation in either of the first direction or the second direction.
Referring to FIG. 3, chassis 12 supports a working assembly, generally indicated by reference numeral 200 . Working assembly 200 includes a cab 21 and a rotatably mounted drum 30 . Working assembly 200 includes a support platform 52 which is suspended in a substantially horizontal orientation from second telescopically adjustable member 116 of chassis 12 by hydraulic cylinder 34 . Hydraulic cylinder 34 can be used to raise and lower support platform 52 . Working assembly 200 is illustrated in more detail in FIG. 16 . Referring to FIGS. 19 and 20, it was determined during construction of the proto-type that having working assembly 200 suspended solely from hydraulic cylinder 34 put undue stress on pivotal connection 56 where hydraulic cylinder 34 connects to chassis 12 . For that reason, underlying support wheels 202 have been provided for support platform 52 . The positioning of support wheels 202 can be altered by hydraulic cylinders 204 which enable support wheels 202 to be steered. Referring to FIG. 16, An operator operates all powered components of apparatus 10 from a cab 21 . Cab 21 is capable of several movements. Cab 21 can be titled to place the operator at an orientation that corresponds to the angle of the groundsurface. This feature is desirable as apparatus 10 was primarily developed for use in uneven terrain, such as drainage ditches. Cab 21 can also be raised and lowered as illustrated in FIGS. 4 and 11. The reason for raising cab 21 is to raise the operator above any dust cloud that may be produced in order to increase visibility during operation. In addition, cab 21 may need to be raised in order to provide clearance. Cab 21 will have to be lowered for better operator access to enter and exit from cab 21 . Referring to FIG. 16, cab 21 is attached to a lift assembly 206 similar to that found on a fork lift. Lift assembly 206 is pivotally mounted to support platform 52 by a pivotal connection 208 . This enables lift assembly 206 to pivot about pivotal connection 208 to alter the angular orientation of cab 21 . Pivotal movement of lift assembly 206 about pivotal connection 208 is performed by hydraulic cylinder 210 . Referring to FIG. 18, lift assembly 206 has a pair of cab engaging supports 212 which move along tracks 214 . Supports 212 are used to secure cab 21 to lift assembly 206 . Hydraulic cylinders 216 are used to move supports 212 along tracks 214 in order to raise or lower cab 21 . Referring to FIG. 17, when the proto-type was built it was determined that there was a need have greater control over drum 30 , than the use of a single hydraulic cylinder 50 would provide. A support 218 was mounted on support platform. 52 to support a pivot linkage 220 that pivoted about a pivotal connection 222 . Pivot linkage 220 has two opposed connection points 224 and 226 . One end 228 of hydraulic cylinder 50 was secured to support platform 52 , the other end 230 of hydraulic cylinder 50 was secured to connection point 224 of pivot linkage 220 . Drum 30 was attached by a pivotal connection 232 to support platform 52 . A connecting member 234 was extended from drum 30 to connection point 226 of pivot linkage 220 . As hydraulic cylinder 50 is extended pivot linkage 220 pivots about pivotal connection 222 . This causes connection point 226 to which connecting member 234 is attached to exert a force upon drum 30 which pivots drum 30 about pivotal connection 232 to an angular orientation.
Referring to FIG. 12, a drive screw 154 was mounted along second telescopically adjustable member 116 . A trolley fixture 155 was provided which travelled along drive screw 154 . Pivotal connection 56 for hydraulic cylinder 34 from which working assembly 200 is supported was attached to trolley fixture 155 . This allows the positioning of working assembly 200 along second telescopically adjustable member 116 to be adjusted. When drive screw 154 rotates in a first rotational direction trolley fixture 155 travels in a first direction along second telescopically adjustable member 116 . When drive screw 154 is rotated in a second rotational direction trolley fixture travels in a second direction along second telescopically adjustable member 116 . An actuating drive motor 153 was provided for rotating drive screw 154 in either the first rotational direction or the second rotational direction, as desired.
Referring to FIGS. 5 and 6, telescopically extendible wheel supports 14 provide a means whereby the height and angular orientation of chassis 12 is adjustable to suit a contour 26 of a ditch 28 . This ensures sufficient clearance can be provided for working assembly 200 .
Referring to FIG. 3, rotation of drum 30 about an axle 33 is powered by a motor 31 . Drum 30 has a first end 36 and a second end 38 . Referring to FIGS. 5 and 6, when drum 30 rotates about axle 33 in the direction indicated by curved arrow 35 , radially projecting teeth 32 broadcast gravel 58 from ditch 28 . Referring to FIG. 3, a shield 40 overlies drum 30 . Shield 40 has a first end 42 , a second end 44 and an upper side 46 . An angular orientation of shield 40 relative to drum 30 is adjustable by means of telescopic cylinders 48 . Referring to FIG. 6, a distance that gravel 58 and debris is broadcast from ditch 28 toward road surface 60 by drum 30 is controlled by angular orientation of shield 40 .
The use and operation of apparatus 10 will now be described in relation to the preferred method and with reference to FIGS. 1 through 20. Referring to FIG. 1 there is illustrated a road 60 that is covered with gravel 58 . Referring to FIG. 2, over time gravel 58 is moved toward ditch 28 and accumulates as deposits 62 altering contour 26 of ditch 28 . Apparatus 10 is transported to a selected site requiring removal of gravel from a ditch, as illustrated in FIG. 2 . Apparatus 10 is transported in the transport position illustrated in FIG. 7 . Apparatus 10 is adjusted to the operating position illustrated in FIG. 3 . The length of second telescopically adjustable member 116 is shortened by applying brakes on wheel 18 of wheel mounting 114 of movable apex 19 and backing up main body 90 . Second telescopically adjustable member 116 is then locked in a selected telescopic position. Second end 89 of first telescopically adjustable member 16 is connected to wheel mounting 114 of movable apex 19 . A length of first telescopically adjustable member 16 can then be expanded in one of two ways. One way is by expanding hydraulic piston 92 to assume an operative position. Another way is by driving and steering support wheel 18 mounted to apex 19 . Referring to FIGS. 5 and 6, apparatus 10 is positioned with at least one support wheel 18 in ditch 28 and the other support wheels on road surface 60 . In order to assume such a position wheel supports 14 and 114 must be telescopically adjusted to accommodate the contours of the ditch and provide clearance for working assembly 200 . Apparatus 10 is then driven slowly along ditch 28 broadcasting gravel 58 from ditch 28 onto road surface 60 with drum 30 , to restore contours 26 of road surface 60 from the state illustrated in FIG. 2 to that illustrated in FIG. 1 . Referring to FIG. 12, the positioning of working assembly 200 along second telescopically adjustable member 116 is adjusted, as required, by activating drive motor 153 to rotate drive screw 154 . This moves trolley fixture 155 to from which working assembly 200 is suspended along second telescopically adjustable member 116 . Referring to FIGS. 19 and 20, as working assembly 200 moves along the ditch, a portion of the weight of working assembly 200 is borne by underlying support wheels 189 to avoid potential strain upon pivotal connection 56 . Referring to FIG. 17, drum 30 is angularly adjusted by activating hydraulic cylinder 50 to alter the position of pivot linkage 220 . This causes pivot linkage 220 to pivot about pivotal connection 222 and causes connecting member 234 to exert a force changing the angular orientation of drum 30 . Cab 21 can be raised to the position illustrated in FIG. 11 when required to enable the operator to look over top of any clouds of dust. Referring to FIGS. 16 and 18, cab 21 is raised by activating hydraulic cylinders 216 to move cab supports 212 along tracks 214 of lift assembly 206 . in order to raise or lower cab 21 . Referring to FIG. 16, the orientation of cab 21 altered to match the ground surface over which apparatus 10 is travelling by activating hydraulic cylinder 210 to pivot lift assembly 206 about pivotal connection 208 . The distance that gravel 58 is broadcast from ditch 28 toward road surface 60 by drum 30 is controlled by telescopic cylinders 48 which adjust the angular orientation of shield 40 to alter the trajectory of gravel 58 .
Although apparatus 10 was developed to groom ditches, it is capable of serving other contouring functions along with a plurality of other ground working functions. These other ground working functions include, but are not limited to, soil aeration, soil mixing, and top soil removal. The proto-type machine had the ability to remove topsoil at a controlled and variable depth. This served to save farmland when excavations were necessary for the installation of pipelines. The topsoil was not only separated from the subsoil, but the topsoil was pulverized in the process. This made it easier to replace the topsoil immediately upon burial of the pipe. Pipeline contractors found this beneficial, as the land was left in a finished condition available for the farmer to enter upon the land. Previously, the topsoil was left in lumps. A further step was needed in the spring to break up the lumps and level the land. This follow up step was not necessary with the proto-type machine.
It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the Claims. | A method and apparatus for ground working. A first step involves providing an apparatus for ground working with telescopically extendible wheel supports which permit the height and angular orientation of the chassis to be adjusted to suit a contour of a ditch. A second step involves positioning the apparatus with at least one support wheel in the ditch and at least one support wheel on the road. A third step involves driving along the ditch broadcasting gravel from the ditch onto the road with the drum. Instead of hauling in replacement gravel from a remote site, gravel is reclaimed from the ditch and broadcast back onto the road. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to data communication equipment or modems.
Data communication equipment (DCEs), or modems, are devices used to transmit and receive binary data over a communication channel. One category of DCEs, sometimes referred to as full-duplex modems, is capable of performing the functions of transmitting and receiving simultaneously. When the modem is transmitting and receiving simultaneously over a two-wire communication link (e.g., transmission over the switched telephone network), an echo of the transmitted signal is commonly present in the signal received from the remote modem. If the transmitted and received signals occupy the same frequency band, it is necessary to remove the echo signal, in order to reliably detect the data sent by the remote modem.
The echo signal typically has a near echo and a far echo component The near echo is generated by the imperfect hybrid couplers in the local modem and the near-end telephone central office. The far echo, on the other hand, is mainly generated by the hybrid couplers in the remote central office and the remote modem. The far echo is delayed in time relative to the near echo. When this delay can be substantial, the echo canceller is often broken into a near-echo and a far-echo canceller component which are also separated by a delay.
High-speed modems typically use bandwidth-efficient modulation schemes such as quadrature modulation. In such systems, the binary data is first mapped into a sequence of complex signal points (symbols) chosen from a constellation with a finite number of points. The real-valued transmitted signal carries information about this complex sequence.
Two-wire, full-duplex, high-speed modems, such as the standard V.32 voiceband modem specified by the CCITT, come equipped with adaptive echo cancellers which are capable of nearly eliminating the echoes of the transmitted signal. An echo canceller is typically implemented as a transversal filter which consists of a tapped-delay line, and a series of variable complex-valued tap coefficients. The inputs to the tapped-delay line are the aforementioned complex signal points. These are appropriately weighted by the tap coefficients to generate as output the real part of the weighted running sum. This represents an approximation of the received real-valued echo signal. The echoes are cancelled by subtracting this estimated echo signal from the real received signal.
Echo cancellers which are implemented as a transversal filter with a complex-input and a real output are often referred to as Nyquist echo cancellers. Nyquist echo cancellers often consist of a near canceller and a far echo canceller. One realization of Nyquist echo cancellers is described by S. Weinstein in the U.S. Pat. No. 4,131,767 (reissue Re31,253).
An echo canceller is typically trained in the absence of the remote signal, during an initialization or training period which occurs prior to data transmission. In many echo cancellers, the transversal filter is trained using the least mean-square (LMS) algorithm. In an LMS algorithm the tap coefficients are continually adjusted to remove any correlation between the complex input symbols and the residual received signal which remains after echo cancellation. However, the time required to accurately train an echo canceller in this manner can be very long, particularly in modems which employ echo cancellers with long transversal filters 10. In the past, fast training methods have been discussed for echo cancellers whose input and output are either both real- or both complex-valued. One method using an ordinary periodic chirp sequence was disclosed by T. Kamitake in IEEE Proc. of ICC'84 (pp. 360-364, May 1984, Amsterdam, Holland) in a paper entitled "Fast Start-up of an Echo Canceller in a 2-wire Full-duplex Modem". A similar method using a pseudo-random shift-register sequence was later described by V. Kanchan and E. Gibson in IEEE Trans. on ASSP (Vol. ASSP-86, No. 7, pp. 1008-1010, Jul. 1988) in a paper entitled "Measurement of Echo Path Response". These methods are not applicable to Nyquist echo cancellers with a complex input and a real output.
In IEEE Proc. of GLOBECOM'87 (pp. 1950-1954, Nov. 1987, Tokyo, Japan), J. M. Cioffi proposed a method for fast simultaneous training of both the near and the far echo cancellers of a Nyquist echo canceller in a paper entitled "A Fast Echo Canceller Initialization Method for the CCITT V.32 Modem." This method is based on the discrete Fourier transform (DFT) and uses a real periodic pseudo-noise sequence, however, it assumes a perfect Hilbert filter (transformer) in the transmitter which is generally not realizable.
When the echo path can be substantially modeled as a linear filter, a transversal filter can effectively reconstruct and substantially cancel the echo signal. However, in certain instances, the far echo may also contain a small amount of frequency offset, also referred to as phase roll, which complicates echo cancellation. Some more sophisticated echo cancellers also include phase-roll compensation circuitry which can track the phase variations in the far echo and thereby remove its detrimental effect. Typically, the phase-roll compensation circuitry includes a phase-locked loop (PLL) to acquire the phase-roll frequency and phase during the training period.
SUMMARY OF THE INVENTION
In general, in one aspect, the invention features a modem for communicating with a remote device in both directions over a channel. The modem includes a transmitter for transmitting information over a channel, a receiver for receiving a signal on the channel possibly including a real echo signal; an echo canceller for estimating the real echo signal, the echo canceller module having variable coefficients; and a trainer module for applying a complex training signal sequence to the transmitter and for computing the variable coefficients based upon correlations between the complex training signal sequence and the corresponding real echo signal.
Preferred embodiments include the following features. The complex training sequence is periodic and has the properties that the real and imaginary parts of the sequence are orthogonal to each other; the autocorrelation of the real part is a first impulse train and the autocorrelation of the imaginary part is a second impulse train. Also, the complex training sequence, the first impulse train, and the second impulse train are all periodic with periods equal to integer multiples of an integer variable L.
In general, in another aspect, the invention is a modem of the type wherein the echo signal includes a near echo having a span of about N 1 and a far echo having a span of about N 2 , the near echo and the far echo being separated by a delay, B, and wherein the training sequence is a periodic sequence having a period equal to an integer multiple of a variable L and the modem further includes a computational element for determining the value of the variable L by: selecting an integer k which is no larger than (B-N 1 )/(N 1 +N 2 ); and setting L equal to an integer existing in an interval R which is substantially defined as follows: [(B+N 2 )/(k+1)]≦R≦[(B-N 1 )/k].
In general, in yet another aspect, the invention is a modem of the type wherein the far echo may have a phase roll, the operation of the echo canceller module is controlled by specifying an estimate of the phase roll frequency and the computed correlations are used to determine a set of echo canceller coefficients and the modem further includes a computational element for (1) computing the difference in phase between a first set and a second set of echo canceller coefficients, both sets having been generated by the trainer module, the first set of echo canceller coefficients corresponding to a time T 1 and the second set of echo canceller coefficients corresponding to a later time T 2 ; and (2) dividing the computed phase difference by the time difference, T 2 -T 1 , to arrive at the estimate of the phase roll frequency.
Preferred embodiments include the feature that the computed phase difference is a weighted average of the phase differences between corresponding elements of the first and second sets of echo canceller coefficients
The invention directly estimates echo canceller coefficients without having to use a few thousand bauds of training time to iteratively approach the optimum values. Furthermore, the method for computing the echo canceller coefficients is accurate and computationally efficient as compared to other methods of computing such coefficients. In addition, the period of time during which echo response data must be gathered for the computations can generally be reduced to a period which is significantly less than the total echo delay of the channel. Consequently, the invention yields very fast echo canceller training, significantly faster than is achievable in previous modems.
The invention offers the additional advantage of producing echo canceller coefficients which are very close to their optimal values and which may result in a residual echo which is within 2 db of its optimal value. Thus, further training using alternative methods such as a least-mean-squares (LMS) algorithm may not be necessary.
The invention can be used for estimating the complex transfer function of a linear system when only the real output of the system is available.
Other advantages and features will become apparent from the following description of the preferred embodiment, and from the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
We first briefly describe the drawings.
FIG. 1 is a block diagram of an echo cancellation modem;
FIG. 2 depicts the autocorrelation properties of a complex periodic training sequence which is used to train the echo canceller shown in FIG. 1;
FIG. 3 depicts the power spectrum of the complex periodic sequence which has the autocorrelation properties shown in FIG. 2;
FIG. 4 is a flow chart of an algorithm for determining the period of the complex periodic training sequence;
FIGS. 5a-c depict the echo response of a representative channel over which the modem shown in FIG. 1 communicates;
FIG. 6 is a flow chart of another algorithm for determining the period of the complex periodic training sequence;
FIG. 7 is a block diagram of a portion of the echo cancellation modem, depicted in FIG. 1, depicting details of the trainer;
FIG. 8 is a flow chart of an algorithm for determining the phase roll frequency and the power of the far echo; and
FIG. 9 is a high level block diagram of a modem which embodies the invention.
STRUCTURE AND OPERATION
Referring to FIG. 1, in an echo cancellation modem 2, which may be of a Nyquist echo canceller type, a scrambler/encoder 6 receives a data bit stream over an input line 4. The scrambler/encoder 6 randomizes the data bits to ensure that any bit pattern is as likely to occur as any other bit pattern and it encodes the bits according to the coding system being used to generate a first sequence of complex symbols. A modulator 8, using a carrier signal 10 of frequency f c , modulates the output of the scrambler/encoder 6 to generate a digital transmit signal 12 consisting of a second sequence of complex symbols. Next, a transmitter filter 14, a digital-to-analog converter 16 and a low pass filter 18 convert the digital transmit signal to an analog signal 20 which is ready for transmission over a channel 22 to a remote device, not shown. A hybrid coupler 24 couples the analog signal 20 to the channel 22.
The hybrid coupler 24 also accepts signals sent over the channel 22 to the modem 2 by the remote device and sends them to a receiver portion of the modem 2 as a received signal 26. During full-duplex communication over the channel 22, the received signal 26 includes both a near echo and a far echo, which may have an associated phase roll. A band pass filter 28 processes the received signal 26 and an analog-to-digital converter 30 converts it to a real digital received signal 32. The analog-to-digital converter 30 produces samples at times kT/M, where T is the baud interval of the local modem's transmitter, M is an integer chosen such that no aliasing will occur in the received signal after sampling, and k is a sampling interval index. (In the embodiment described herein, M is chosen
to be equal to 3. A combiner 34 combines the samples of the real digital received signal 32 with corresponding samples of an estimated echo signal 36 to generate an echo-cancelled signal 38. Finally, a receiver 40 processes the echo-cancelled signal 38 to produce a received data bit stream 42 corresponding to the bit stream sent by the remote device.
An echo canceller module 44 within the modem 2 generates the estimated echo signal 36. In the echo canceller module 44, a delay line 46 receives the complex transmit signal 12 and produces two groups of signals 48a-b which are separated in time from each other by a bulk delay. The group 48a corresponds to the near echo signal and includes a plurality of complex symbols each of which are delayed in time relative to each other so that they span the near echo signal; whereas the group 48b corresponds to the far echo signal and includes a plurality of other complex symbols each of which are delayed in time relative to each other so that they span the far echo signal. The group of delayed complex symbols 48a, corresponding to shorter periods of delay, are processed by a near echo canceller 50 and the group of delayed complex symbols 48b, corresponding to longer periods of delay, are processed by a far echo canceller 52. Both the near echo canceller 50 and the far echo canceller 52 include variable coefficients which are trained so that the echo cancellers 50 and 52 produce outputs which are accurate estimates of the near echo and the far echo, respectively. A summer 54 combines the outputs of the near echo canceller 50 and the far echo canceller 52 to generate the estimated echo signal 36.
The echo canceller module 44 also includes a phase roll compensator (PRC) 56 which controls the far echo canceller 52. After being trained, the PRC 56 introduces a phase roll into the output of the far echo canceller 52 which approximates the phase roll of the far echo in the received signal 26.
Training of the variable coefficients of the echo canceller module 44 is controlled by a training signal generator 58 and a trainer 60. During training, which may occur prior to data communication or during a period interrupting data communication, the training signal generator 58 generates a special echo training sequence that is sent to the remote device and the trainer 60 monitors the resulting real digital received signal 32. The remote device remains silent during this period of echo training, thus, the resulting real digital received signal 32 basically consists only of near and far echoes. Based upon the monitored echo signal, the trainer 60 computes echo canceller coefficients which set the variable coefficients in the near echo canceller 50, the far echo canceller 52 and the PRC 56 so that the echo canceller 44 generates an estimated echo signal 36 closely approximating the monitored echo. The echo canceller module 44 uses the echo-cancelled signal 38 as an error signal indicating how accurately the echo canceller module 44 has estimated the echo using the coefficients estimated by the trainer 60. Further fine adjustment of the echo canceller coefficients may be incorporated using the echo-cancelled signal 38 and the well known least-mean-square (LMS) adaptive algorithm.
The training generator 58 generates a complex periodic sequence, p(n)=p r (n)+jp i (n), having a period of 2L and the following autocorrelation properties: ##EQU1##
As indicated the real and imaginary parts of the training sequence are orthogonal, i.e., the cross-correlation of length 2L between p r (n) and p i (n) is zero for all n. The properties of the autocorrelation of the real and imaginary parts of p(n) are illustrated in FIG. 2. And the corresponding power spectrum of such a training sequence has the form illustrated in FIG. 3. Note that the power spectrum of p r (n) and p i (n) are the 2L-point discrete Fourier transforms of the correlations given by Eqs. (1) and (2), above.
Using a training sequence having the above characteristics, the trainer 60 calculates the echo canceller coefficients for the near echo and the far echo cancellers 50 and 52 by computing correlations between a period of the complex training sequence 12 and the real digital received signal 32. To appreciate that the computed correlations yield the desired values for the echo canceller coefficients, it is useful to review the mathematics describing the operation of the system.
The echo channel can be considered as a linear system with a complex impulse response c(t). If the transmitted data symbols are denoted as d(nT), where T is the baud time interval and n is the baud interval index, then the output of the system sampled at every T, y(nT), is related to the input, d(nT) as follows:
y(nT)=Re[c(nT) ○ d(nT)] (4)
where ○ denotes the linear convolution operation. In this example, y(nT) represents the real sampled digital received signal 32. Actually, if the received signal 26 is sampled at a rate 3/T, as it is in the above-described embodiment, then the output signal y(t) may be written as y(nT+mT/3), where m=0,1,2. This can be more simply denoted as y m (n). Using the same convention, c(nT+mT/3) can be rewritten as c m (n) which is the impulse response of the echo channel sampled at nT+mT/3 and equation (4) becomes
Y.sub.m (n)=Re[c.sub.m (n) ○ d(n)] (5)
Substituting the complex training sequence p(n) for d(n) results in the following:
Y.sub.m (n)=Re[c.sub.m (n) ○ p(n)] (6)
After the channel is fully excited by the training sequence p(n), the real echo y m (n) is also periodic with a period of 2L, if the channel is time-invariant, and then the correlation between the real echo and the sequence is:
Y.sub.m (n) ○ .sub.2L p(n)=Re[c.sub.m (n) ○ p(n)] ○ .sub.2L p(n) (7)
Separating c m (n) and p(n) into their real and imaginary parts yields:
Y.sub.m (n) ○ .sub.2L p(n)= [c.sub.mr (n) ○ p.sub.r (n)-c.sub.mi (n) ○ .sub.2L [p.sub.r (n)+jp.sub.i (n)](8)
where c mr (n) and c mi (n) are the real and imaginary parts of c m (n), respectively, and j is ≧-1. Since the real and imaginary parts of the chosen p(n) are orthogonal under the circular correlation of length 2L, the above equation reduces to:
Y.sub.m (n) ○ .sub.2L p(n)=c.sub.mr (n) ○ [p.sub.r (n) ○ .sub.2L p.sub.r (n)]-jc.sub.mi (n) ○ [p.sub.i (n) ○ .sub.2L p.sub.i (n)] (9)
y.sub.m (n) ○ .sub.2L p(n)=c.sub.mr ((n).sub.MOD 2L)+c.sub.mr ((n-L).sub.MOD 2L)-jc.sub.mi ((n).sub.MOD 2L)+jc.sub.mi ((n-L).sub.MOD 2L) (10)
y.sub.m (n) ○ .sub.2L p(n)=c*.sub.m ((n).sub.MOD 2L)+c.sub.m ((n-L).sub.MOD 2L) (11)
where * denotes the complex conjugate operation. Because of the periodicity, only the correlation for 0≦n≦2L-1 need be considered. From Eq. (11) it is apparent that the correlation results for 0≦n≦2L-1 contain two duplicated (the first of which is complex conjugated) versions of c m (n), which have a span no greater than L. Hence, one of the versions provides enough information.
In general terms, the properties of the training sequence, as shown in FIGS. 2 and 3 and as specified in Eqs. 1-3, have the following significance. Note that the objective is to determine the impulse response of the echo channel which, of course, theoretically can be directly determined by stimulating the echo channel with an impulse. There is at least one problem, however, with using an impulse. Its energy is too concentrated in time and the impulse peak may drive the signal into nonlinear regions of the channel where the data signal does not normally operate during normal communications. By distributing the power evenly over time, as is implied by FIG. 3, one can transmit more energy with the training sequence and thus can more fully excite the channel without driving the transmitted signal into its nonlinear regions of operation. Moreover, by using a training sequence whose autocorrelation function is an impulse train, as shown in FIG. 2, one can still readily and directly determine the impulse response of the echo channel by simply correlating the training sequence with the echo response corresponding to the training sequence. That is, the resulting function, namely, y m (n) ○ 2L p(n), corresponds to the echo channel response that one would obtain by stimulating the channel with the impulse train represented by the autocorrelation of p(n). The orthogonality property of the real and imaginary parts of the training sequence simply guarantees that the real and imaginary parts do not interfere with each other, when the real and imaginary parts of the coefficients are estimated.
According to the correlation properties given by Eqs. (1) and (2), every half period of the correlation in Eq. (9) yields an estimate of the sampled echo channel response c m (n), if the total span of the echo is less than the half period L. Thus, it is verified that by using the periodic sequence characterized by Eqs. (1), (2) and (3), the real and imaginary parts of c m (n) can be obtained by simply performing circular correlation between a 2L-long segment of the samples of the real digital received signal 32 and the real and imaginary parts of one period of the periodic sequence p(n). There will be a sign difference between the imaginary parts of the estimated and the actual responses, if the correlation from the first half period is used. Since the real digital received signal is periodic, an alternative way to estimate the echo canceller coefficients c m (n) is to perform a linear correlation of length 2L between the real and imaginary parts of one period of the periodic sequence p(n) and a 3L-long segment of the real received signal 32.
For a Nyquist echo canceller with three subcancellers, the correlation processing is repeated for each incoming T/3 sample. Namely, Eq. (9) is repeated for m=0,1,2. Thus, there are three incoming samples per baud and three subcanceller coefficients are obtained per baud interval.
A number of periodic sequences have the properties described in Eqs. (1) through (3). However, it is desirable that the sequence have a small peak-to-RMS (root-mean-square) ratio so that there is a lower risk of driving the transmitted signal into regions of nonlinear operation. A periodic sequence which has this desirable property is one for which the phase of its discrete fourier transform obeys a square law of frequency. Such a sequence is defined as follows
(1) For 0≦n≦L, and if
(a) L is even, then ##EQU2## (b) L is odd, then ##EQU3## (2) For L≦n≦2L, then the second half of the sequence is the complex conjugate of the first half of the sequence, namely:
p.sub.r (n)=p.sub.r (n-L), and (16)
p.sub.i (n)=-p.sub.i (n-L) (17)
Another sequence which has a slightly higher peak-to-RMS ratio but is easier to compute in real time since fewer cosine values are required is:
(1) For 0≦n≦L, ##EQU4## (2) For L≦n≦2L,
p.sub.r (n)=p.sub.r (n-L), and (20)
p.sub.i (n)=-p.sub.i (n-L) (21)
where INT[(L-1)/2] is the largest integer which is less than or equal to [(L-1)/2].
Modem 2 implements the algorithm illustrated in FIG. 4 to determine the value of L. The algorithm determines the period which must be used in constructing the periodic sequence so that the training sequence produces interleaved, non-overlapping near and far echoes when the channel is fully excited. What this means can be more clearly understood with the aid of FIGS. 5a-c.
FIG. 5a shows the echo response of the channel to a single impulse at t=0. The near echo occurs first, followed by the far echo delayed in time by B. Note that the span of the near echo and span of the far echo is less than or equal to N 1 and N 2 , respectively. When the channel is excited by the impulse train shown in FIG. 5b, the echo response is as shown in FIG. 5c. Until the far echo appears, the echo response consists of a train of near echoes, one occurring every L baud. After B bauds have elapsed, the channel becomes fully excited and the far echoes begin to appear, also separated by a period of L. To utilize the near and far echoes thus generated for computing the echo canceller coefficients, it is desirable that the near and far echoes are non-overlapping as shown in FIG. 5c. In addition, it is desirable that the total time period, L, over which the two echoes occur should be as short as possible so that the computations involve the minimum number of bauds. The algorithm shown in FIG. 4 selects the L which satisfies these two criteria.
During the period of echo canceller training but prior to transmitting the special echo training sequence, the modem measures the far echo round trip delay, B, introduced by the channel 22 (step 100, FIG. 4). The delay, B, is equal to the length of time required for the far echo to come back after the training signal is transmitted One such method for determining the far echo delay is described in the CCITT V.32 standard.
Note that N 1 and N 2 are usually determined at the time of designing the modem. Generally, they are empirically determined by studying the typical characteristics of channels. It is preferable to select N 1 and N 2 so that they are upper bounds on the duration of the corresponding echoes which one expects to receive.
After modem 2 has measured the far echo delay, B, it computes a variable, k, which is defined as follows:
k=INT[(B-N.sub.1)/(N.sub.1 +N.sub.2)] (step 110)
where INT[x] means the largest integer that is less than or equal to x.
Next, modem 2 tests k to determine whether it is greater than zero (step 115). If k is greater than zero, the modem computes two additional variables, p 1 and p 2 , defined as follows:
p.sub.1 =(B+N.sub.2)/(k+1) (step 120)
p.sub.2 =(B-N.sub.1)/k (step 130)
Then, in step 140, modem 2 determines whether an integer exists in the range R defined as follows:
p.sub.1 ≦R≦p.sub.2
If there is an integer within the range R, modem 2 sets L equal to the smallest integer within the range (step 150). That is, if p 1 is an integer, then L=p 1 ; otherwise, L=INT[p 1 +1]. The modem then branches to step 160 where it computes f, defined as follows:
f=B-kL
The variable f indicates the location of the far echo within the period L. The far echo is located between f and f+N 2 -1. Using this information, modem 2 assigns the correlation calculations for each baud in the interval of length L to the corresponding component of the echo.
In step 140, if there is no integer within the range R, then modem 2 branches to step 170 where it decrements k by one and then returns to step 120. Steps 120 through 140 are repeated until the range R includes an integer.
If in step 115 k is not greater than zero, then modem 2 tests if k equals zero (step 116). If k equals zero, modem 2 sets L equal to B+N 2 and then branches to step 160 to compute f. However, if k is less than zero, then modem 2 sets L equal to N 1 +N 2 , sets f equal to N 1 (step 118) and then exits the algorithm (step 119).
The algorithm yields an L which lies within the following interval:
N.sub.1 +N.sub.2 ≦L≦2(N.sub.1 +N.sub.2)-1,
for any practical values of N 1 , N 2 , and B.
For finite precision implementations of the algorithm, the selected value for L may be incorrect or non-optimal. If L is incorrect, the near and far echoed may overlap. Whereas, if L is non-optimal, the obtained period is not the smallest possible period. These errors are due to round-off error effects. The critical stages of the algorithm are in step 140, where the range R is tested for the presence of integers, and in step 110, where the initial value of k is computed. To avoid the problems associated with round-off errors, the algorithm may be modified as shown in FIG. 6.
Steps 200 and 215 correspond to steps 100 and 115, respectively, of FIG. 4. Step 210 is slightly different from step 110, namely, k=INT[(B-N 1 )/(N 1 +N 2 )+δ 0 ] where δ 0 is a small positive correction number. In step 215 if k is greater than zero, modem 2 computes p 1 (step 220) and p 2 (step 230) which are defined differently from what was described above. Namely,
p.sub.1 =(B+N.sub.2)/(k+1)+δ.sub.1 (step 220)
p.sub.2 =(B-N.sub.1)/k+δ.sub.1 (step 230)
where δ 1 is a small correction number.
Then, in step 240, modem 2 determines whether an integer exists in the range R as previously defined, i.e.:
p.sub.1 ≦R≦p.sub.2
For this test, however, p 1 is treated as an integer if its fractional part is less than a threshold δ 2 .
As before, if there is an integer within the range R, modem 2 sets L equal to the smallest integer within the range (step 250). That is, if p 1 is an integer, then L=p 1 ; otherwise, L=INT[p 1 ]+1. The modem then branches to step 260 where it computes f, as previously defined, i.e.:
f=B-kL
Finally, modem 2 determines if N 1 ≦f<L-N 2 (step 280). If it is, the algorithm stops (step 219).
If an integer does not exist within the range (step 240) or if f does not lie within the defined interval (step 280), modem 2 branches to step 270 where it decrements k by one. Then, it branches back to step 215 to repeat the steps until an L which satisfies the conditions of the algorithm is found.
In step 215, if k is not greater than zero, modem 2 branches to step 216 which corresponds to step 116 of the algorithm shown in FIG. 4. Indeed, the sequence followed after branching to step 216 is the same as that described for FIG. 4. That is, modem 2 implements steps 217 and 218 which are the same as steps 117 and 118, respectively, in FIG. 4.
The correction numbers, δ 0 and δ 1 , and the threshold, δ 2 , depend upon the word length and the rounding scheme used in the computations. It is preferable that the word length used in computation should be long enough For example, when 16 bit fixed-point arithmetic is used, double precision computations are preferable. In this case, experiments have determined that when δ 0 =2 -15 , δ 1 =2 -14 and α 2 =2 -12 , then the algorithm computes a correct L and step 280 may not be necessary.
The initial values of the coefficients of the near and far echo cancellers are computed as follows. The required half-period L of the special training sequence is computed based on the value of B as described above. The trainer 60 then computes, in real time, the required periodic complex training sequence according to the value of L. The computed training complex sequence is then transmitted by the transmitter for at least k'+4 half-periods, or (k'+4)L bauds, where k'=k if k>0 or k'=0 otherwise, and k is obtained during the determination of L. After at least k'+1 half-periods, or (k'+1)L bauds, of the training sequence have been transmitted, the trainer 60 stores the real received digital signal samples 32 in 3 buffers 70, 72 and 74, shown in FIG. 7, which are T-spaced delay lines that are each at least 2L samples long. Another 2L bauds later, after each buffer has received 2L samples, and while the transmitter continues sending the periodic sequence, trainer 60, using correlators 76a-f, starts to perform correlations of the input samples with the real and imaginary parts of one period of the periodic training sequence The correlations can either be circular correlations if the same samples in the 2L long buffers 70, 72 and 74 are being used, or they can be linear correlations if first-in-first-out (FIFO) buffers that receive 3 new samples per baud are employed instead. The real coefficients are directly obtained from the correlation results, while the imaginary part of the coefficients are equal to the correlation results multiplied by (-1) k' . Assuming three complex coefficients, one for each subcanceller, are computed per baud, a time period of N 1 bauds will be used to compute all the coefficients of the near echo canceller 50 (see FIG. 1). The coefficients of the far echo canceller 52 are computed in the same way as computing the near canceller coefficients. The coefficients of the far canceller 52 can be computed in N 2 bauds.
The modem uses the calculated far echo canceller coefficients to set the variable coefficients of PRC 56. PRC 56 may employ digital phase-locked loop (PLL) technology such as that described in U.S. Pat. No. 4,813,073 entitled "Echo Cancellation", issued on Mar. 14, 1989, and incorporated herein by reference. To train the PLL in PRC 56, it is necessary to accurately estimate the phase-roll frequency and to measure the far echo power. Modem 2 implements the algorithm illustrated in FIG. 8 to compute both of these characteristics.
Assuming that the frequency of the far echo phase-roll is ω p radians/s, the far echo is modulated by exp[jω p t]. The far echo received at time T 1 will have a phase-rotation ω p T 1 radians relative to the far echo without phase-roll. If the frequency ω p is relatively low, such that in a 2L long segment, all the received signal samples have approximately the same phase rotation, the correlation property between the training sequence and the received signal described above will approximately still hold. An estimated far canceller coefficient using the received signal at the time T 1 will be equal to the coefficient estimated without phase-roll multiplied by exp[jω p T 1 ]. Similarly, the same far echo canceller coefficient estimated at a later time T 2 is multiplied by exp[jω p T 2 ]. Thus, the phase-roll frequency ω p can be estimated by dividing the angle difference, Φ=(T 2 -T 1 )ω p , between these two far echo canceller coefficients by the time difference T 2 -T 1 . The estimation procedure is described below.
First, modem 2 computes at least two sets of far echo canceller coefficients using the correlation technique described above (step 300). A first set of coefficients is computed corresponding to time T 1 and a second set of coefficients is computed corresponding to time T 2 , which occurs D baud after time T 1 . In practice, it is convenient to choose D=L, although D can be another positive integer value. Then, in step 310, modem 2 computes the estimated phase difference between the two sets of calculated far echo canceller coefficients.
One way of determining the estimated phase difference is by computing the sine of the phase difference, φ m ,n, between each of the corresponding coefficients in the two sets of calculated far echo canceller coefficients.
Sin φ m ,n is related to the calculated coefficients in the following way: ##EQU5## This is approximated as follows: ##EQU6## where c m ,r (n) and c m ,i (n) are the real and imaginary parts of c m (n), m=0,1,2, respectively, |c m (n)| is the magnitude of c m (n) and it is assumed that the magnitudes of the two calculated coefficients are equal.
If the absolute value of the angle φ m ,n is small, e.g. less than 20 degrees, then
φ.sub.m,n ≈sin φ.sub.m,n.
Theoretically, the angle between any pair of far echo coefficients should be the same. However, noise and other interferences may undercut the validity of this relationship. Therefore, to reduce the effect of any noise or interference and improve the accuracy of the estimate of the phase roll frequency, the estimated angle may be averaged over all of the pairs of far echo coefficients. That is, in step 310 modem 2 may compute the following:
AVG(φ)=Σ.sub.n,m a.sub.m,n φ.sub.m,n
where Σ n ,m a m ,n =1, in order to assure that AVG(φ) is an unbiased estimate of the angle.
To obtain an optimal weight a m ,n, it is preferable to set a m ,n equal to c m ,i 2 (n)+c m ,r 2 (n)/Σ m ,n [c m ,r 2 (n)+c m ,r 2 (n)]. When this is done, note that AVG(ω) equals: ##EQU7##
It may be preferably to estimate the average angle by computing the just-cited equation rather than by computing the angle for each coefficient and then averaging all of the computed angles. The reason is that the former approach involves only one division; whereas the later approach involves many divisions. Since division is a time consuming and inefficient process when using commercially available digital signal processors, it is desirable to minimize the number of divisions.
After the estimated phase difference is computed, modem 2 computes an estimate of the average phase roll frequency by dividing AVG(φ) by DT=T 2 -T 1 (step 320).
Finally, in the step 330 modem 2 determines the power of the far echo by computing the following relationship: ##EQU8## where the overbar denotes the ensemble average operation and d(n) is the data symbol which is transmitted. The value of P f is then used for optimal scaling of the PLL coefficients in PRC 56.
The modem may be implemented by a multiple processor architecture, as shown in FIG. 9. That is, it has a general host processor 62, which performs overall control and data movement functions; a signal processing element 64, which performs the functions of the transmitter and echo canceller, including the implementation of the algorithms described above; and another signal processing element 66, which performs the functions of the receiver 40. A modem generally of this type is described in U.S. patent application Ser. No. 586,681 entitled Processor Interface Circuitry, to Qureshi et al. filed Mar. 6, 1984, incorporated herein by reference.
Other embodiments are within the following claims. | An echo cancellation modem having a fast training echo canceller in which the echo cancellation coefficients are computed by taking correlations between a complex, periodic training signal sequence and a real component of the corresponding echo signal. The modem includes a receiver circuit for detecting a signal on a channel possibly including an echo; an echo canceller for estimating the real component of the echo signal; training circuitry for applying the complex training sequence to the channel and for taking correlations between the training sequence and the real component of the corresponding echo signal. The modem also includes a computational element for computing the period of the periodic sequence, generating the complex periodic train sequence in real time and for computing a phase roll frequency based upon the computed echo cancellation coefficients. | 7 |
[0001] This invention was developed with support from the United States Air Force Research Laboratory under contract F0 860-001-0012. The United States government has certain rights to this invention.
BACKGROUND OF THE INVENTION
[0002] The invention generally relates to holography, and particularly relates to the readout of holograms with improved diffraction efficiency by using a resonant system in the path of the reference beam of the hologram.
[0003] Holograms are typically recorded as a result of interference between two mutually coherent light beams, the signal beam and the reference beam. The signal beam carries the information, typically in the form of amplitude modulation imprinted on the wavefront. The reference beam interferes with the signal beam creating an interference pattern that is then recorded in photosensitive material. In the simplest case, the reference is a plane wave. On reproducing the reference beam originally used to record the hologram, one is able to reproduce the signal beam as a result of diffraction from the previously recorded interference pattern.
[0004] It is known that multiple holograms may be superimposed or multiplexed in volume media. Individual holograms may be accessed selectively in a way similar to the individual detection of multiple periodicities in crystal lattices using Bragg diffraction. The Bragg selectivity property of volume holograms forms the basis of most of the current applications of volume holograms. These include volume holographic memories, in which several holograms are multiplexed so as to yield high storage capacities, opto-electronic interconnections for telecommunications and artificial neural networks, and four dimensional (spatial and spectral) imaging.
[0005] The light efficiency of a hologram is measured by a unitless quantity called the diffraction efficiency η, defined as the ratio of the diffraction power divided by the incident power. If the diffraction efficiency is low, then the aforementioned applications are limited by various factors including signal to noise ratio considerations. For example, although photorefractive crystals are rewritable, they typically yield low diffraction efficiencies before non-linear effects set in to affect the recording process. The maximum achievable η depends on the holographic materials, but conventional holographic materials having high diffraction efficiency are not typically suitable for certain applications. For example, photopolymers afford high diffraction efficiencies, but are difficult to maintain and control, and may exhibit material shrinkage. Photorefractive polymers afford high diffractive efficiencies, but are inconvenient to use since they require voltages in the order of MV/cm during the recording process. This requirement limits the useful hologram thickness (and thereby the information capacity) in practical applications. These holograms also violate the Born approximation and their behavior is qualitatively different from that of weak holograms. For example, they typically exhibit increased crosstalk between Bragg-multiplexed holograms due to re-diffraction among multiple Born orders.
[0006] A principle constraint in the practical realization of most applications of volume holograms, therefore, is that the diffraction efficiency yielded by currently available holographic recording media suitable for volume holography is very low. The diffracted beams obtained from these volume holograms are relatively weak thus rendering them unsuitable for many applications.
[0007] There is a need, therefore, for a system and method of improving the diffraction efficiency of holograms, and in particular volume holograms.
SUMMARY OF THE INVENTION
[0008] The invention provides a resonator system for use in illuminating the input to a diffractive element. The system includes a source of an electromagnetic field having a wavelength of λ, and first and second optical elements, each of which is at least partially reflecting. The first and second optical elements are separated from one another such that the optical path between the optical elements has a distance
( 2 m + 1 ) λ 4 ,
[0009] , wherein m is an arbitrary integer. In certain embodiments, the diffractive element is a hologram, and the first and second optical elements are mirrors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following description may be further understood when with reference to the accompanying drawings in which:
[0011] [0011]FIG. 1 shows a diagrammatic schematic illustration of a system in accordance with an embodiment of the invention;
[0012] [0012]FIG. 2 shows a diagrammatic schematic illustration of a system in accordance with another embodiment of the invention;
[0013] [0013]FIG. 3 shows a graphical illustration of variations in the optical path of a resonator verses the diffracted power in a system in accordance with an embodiment of the invention;
[0014] [0014]FIG. 4 shows a graphical illustration the optical path of a resonator verses the diffracted power in a system in accordance with an embodiment of the invention; and
[0015] [0015]FIGS. 5 and 6 show diagrammatic schematic illustrations of another system in accordance with a further embodiment of the invention an illustrative view of.
[0016] The drawings are shown for illustrative purposes and are not to scale.
DETAILED DESCRIPTION OF THE INVENTION
[0017] As shown in FIG. 1, a system in accordance with an embodiment of the invention includes a resonant structure in which a conventional weakly diffracting volume hologram 10 may be positioned. The resonator consists of a partially reflecting mirror 12 and a perfectly reflecting mirror 14 . The resonator ensures that all incident light undergoes multiple passes through the volume hologram with a certain amount of light being diffracted out at each pass. By adjusting the length of the resonator, the light that is diffracted out at each pass may be ensured to be in phase. Simultaneously, the backward-propagating (or reflected) fields add destructively, ensuring that all incident power is channeled in the direction of the diffracted beam.
[0018] In particular, incident light into the resonator enters from as indicated at 16 at an angle that is oblique with respect to the front surface 18 of the mirror 12 . The incident light is directed through the volume hologram 10 producing a diffracted field having an amplitude of C, as shown in FIG. 1. The forward propagating field (having an amplitude of A 1 ) that travels through the resonator in the forward direction is fully reflected by the mirror 14 , and the return propagating field (having an amplitude of D 1 ), is partially reflected by the mirror 12 . The field that is refracted through the mirror 12 has amplitude of B 1 , and the amplitude of the field that is again reflected in the forward direction is A 2 . The hologram is formed by the summation of all of the diffracted fields C 1 +C 2 +C 3 etc.
[0019] The conditions for resonance may be derived by first identifying certain variables and relationships. The optical path within the resonator may be denoted as l, and the natural diffraction efficiency of the hologram (when not in a resonator) may be denoted as η. The amplitude reflection coefficient of the mirror 12 in the forward direction may be denoted as r, and the amplitude reflection coefficient of the mirror 12 in the backward direction may be denoted as r′. The corresponding amplitude transmission coefficients of mirror 12 in the forward and backward directions are denoted as t and t′. It is known that r 2 +tt′=1 and r=−r′.
[0020] The amplitude of the beam incident of the front face of mirror 12 as indicated at 16 may be set to 1 without compromising the generality of the following analysis. The values A j , B j , C j , and D j, denote the amplitude of the j th order forward propagating, refracted, diffracted and return propagating fields respectively, where j=1, 2, 3 . . . . The value B 1 =r, and the values A j , B j+1 , C j , and D j are calculated as follows:
A j =t ( r ′{square root}{square root over ((1−η)))} j−1 e 2i(j−1)kl
B j+1 =tt ′{square root}{square root over ((1−η))}( r ′{square root}{square root over ((1−η)))} j−1 e 2ijkl
C j ={square root}{square root over (ηt)}( r ′{square root}{square root over ((1−η)))} j−1 e ik(2(j−1)l+d)
D j =t {square root}{square root over ((1−η))}( r ′{square root}{square root over ((1−η)))} j−1 e 2ijkl
[0021] The total amplitude of the refracted field B may be expressed as:
B = r + t t ′ ( 1 - η ) 2 i k l ∑ j = 1 ∞ ( r ′ ( 1 - η ) 2 i k l ) j - 1
[0022] which may be simplified to:
B = r + ( 1 - η ) i2 k l 1 + r ( 1 - η ) i2 k l
[0023] The intensity (I B ) of the reflected field, therefore, may be expressed as:
I B = B B * = r 2 + ( ( 1 - η ) ) 2 + 2 r ( 1 - η ) cos ( 2 k l ) 1 + ( r ( 1 - η ) ) 2 + 2 r ( 1 - η ) cos ( 2 k l )
[0024] Resonance may be obtained by setting the reflected intensity I B to zero. The intensity of the reflected forward propagating fields as well as the diffracted fields are thereby maximized.
[0025] The conditions for resonance and 100% diffraction efficiency for oblique incidence as shown at 16 in FIG. 1 are given by r={square root}{square root over (1−η)} and
k l = ( 2 m + 1 ) π 2
[0026] where m is an arbitrary integer. Systems involving oblique incidence, therefore, are somewhat limited in that the surface area of the mirrors 12 and 14 may not be infinitely large to accommodate the drift distance between each forward propagating field and its associated return propagating field.
[0027] As shown in FIG. 2, a system in accordance with another embodiment of the invention involves the use of incident light as indicated at 26 that is directed through a partially reflecting mirror 22 at an angle that is normal to the front surface 28 of the mirror 22 . The forward propagating light field travels through a volume hologram 20 producing a diffracted field, and a backward propagating field is reflected by a perfectly reflecting mirror 24 and directed back toward the mirror 22 as discussed above with reference to FIG. 1. The conditions for resonance for the system of FIG. 2 are r=1−η and
k l = ( 2 m + 1 ) π 2
[0028] where m is an arbitrary integer. Because the return propagating field in FIG. 2 is at normal incidence with respect to the return surface of the volume hologram 20 , a second phase conjugated diffracted field may be produced as indicated at 29 having an amplitude of C′.
[0029] When absorption by the resonator system (including the hologram) is considered, the resonance condition is satisfied by |r|=1−η−b and the value cos(2kl)=1 if r<0, and cos(2kl)=−1 if r>0, where r is the amplitude reflection coefficient of the front partially reflecting mirror, η is the diffraction efficiency of the hologram, b is the absorption of the resonator system, and K= 2π /HD λ
[0030] This applies if η is fixed and r is varying.
[0031] If η is varying and r is fixed, then
| r | = 1 - η - b = 2 | r | - 2 | r | b - b 2 + | r | b T h u s ,
η = ( 2 - b ) ( 1 - | r | + | r | b ) ( 2 + | r | b )
[0032] and the value cos(2kl)=−1 if r>0, and cos(2kl)=1 if r<0.
[0033] The use of volume holograms in a resonator of the invention may be more Bragg-selective than volume holograms that are used without a resonator of the invention. Because an incident light field undergoes multiple passes within the resonator, the effective length and Bragg selectivity in resonant architectures are enhanced. If the quality factor of the resonator is denoted by Q, then the improvement in Bragg selectivity may be observed from the following approximation:
Δθ resonantor = Δθ hologram Q
[0034] Qualitatively, this approximation is derived from the fact that each photon completes on average Q round trips inside the resonator before exiting. The improved selectivity, together with improved diffraction efficiency, provides numerous potential benefits, including improved capacity for holographic memories, improved resolution for holographic imaging, and improved channel separation for holographic communication and interconnection applications.
[0035] A specific example of a system as shown in FIG. 2 was constructed with a 90% partially reflecting mirror (intensity reflectivity), and a hologram having an efficiency of 10%. As shown at 50 in FIG. 3, power of the diffracted field is harmonically related to the length l of the optical path in the resonator. The distance between the mirrors, therefore, should be precisely calibrated. As shown at 54 in FIG. 4, the diffracted power may be optimized dependent on the diffraction efficiency of the hologram and the reflectivity of the partially reflecting mirror.
[0036] As shown in FIG. 5, a system in accordance with a further embodiment of the invention includes a partially reflecting mirror 60 and a perfectly reflecting mirror 62 , each of which has a focal distance of f, and the optical path within the resonator is defined as 2f. Similar to the embodiment discussed above with reference to FIG. 2, incident light from a planar light field (as indicated at 64 ) enters the resonator, passes through the hologram 66 , and is reflected by the perfectly reflecting mirror 62 . The hologram may be formed in any direction as dictated by the physical arrangement of the reference and object fields when the hologram was originally recorded. The hologram 66 may comprise a multiplexed holographic recording, permitting many different reconstructions to be produced from the same holographic material by moving the hologram in a direction that is transverse to the length of the resonator as shown at 68 in FIG. 6. In this fashion, a large number of separate images may be recorded in a single multiplexed recording, and viewed independent of one another by adjusting the position of the hologram with respect to the resonator.
[0037] The invention provides a system and method of improving the diffraction efficiencies of holograms to a theoretical maximum of up to 100% without violating either the Born or paraxial approximations. Holographic resonators in accordance with certain embodiments of the invention may be particularly suitable for applications in optical science, including optical networking, optical storage, and optical imaging. In further embodiments, any diffractive element may be used instead of a hologram. In still further embodiments, a perfectly reflecting mirror in any of the illustrated embodiments may be replaced with a partially reflecting mirror to provide additional output ports, and/or may further include additional mirrors to provide a plurality of resonant cavities.
[0038] Those skilled in the art will appreciate that numerous modifications and variations may be made to the above disclosed embodiments without departing from the spirit and scope of the invention. | A resonator system is disclosed for use in illuminating an input to a diffractive element. The system includes a source of an electromagnetic field having a wavelength of λ, and first and second optical elements, each of which is at least partially reflecting. The first and second optical elements are separated from one another such that the optical path between the optical elements has a distance
( 2 m + 1 ) λ 4 ,
, wherein m is an integer. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical field of the Invention
[0002] The present invention relates to a process for producing a sulfonylimide compound represented by the formula:
MN(SO 2 R f 1 )(SO 2 R f 2 )
[0003] 2. Description of Prior Art
[0004] Sulfonylimide compounds are safe as a solute of a battery electrolyte and battery electrolyte that uses the sulfonylimide compound as a solute has a high energy density and exhibits high conductivity. Hence, the sulfonylimide compounds are regarded as a promising solute of a battery electrolyte. Also, the sulfonylimide compounds are useful as a Lewis acid catalyst and an ionic conduction agent.
[0005] The sulfonylimide compounds represented by the formula (I) MN(SO 2 R f 1 )(SO 2 R f 2 ) may be synthesized by the process proposed by D. D. Desmarteau et al. in INORGANIC CHEMISTORY VOL. 23, No. 23, P3720-3723 (1984).
[0006] In this synthetic method, as shown by the following formula, trifluoromethylsulfonyl fluoride is reacted with ammonium, the resulting product is treated using hydrochloric acid to produce trifluoromethylsulfonylamide, which is then reacted with sodium methylate and then with hexamethyldisilazane, and the resulting product is reacted with trifluoromethylsulfonyl fluoride, thus obtaining an imide sodium salt.
[0007] However, this process involves multi-reaction steps and hence takes longer. Also, expensive hexamethyldisilazane must be used to obtain an intermediate, and the yield is as low as about 50%.
[0008] In the above-described formula (I), M represents any one of Li, Na, K and Cs among alkali metals of group Ia in the periodic table. R f 1 and R f 2 , which may be the same or different, respectively represent any one of a straight chain or branched compound of a fluoroalkyl, perfluoroalkyl, fluoroallyl and fluoroalkenyl group having 1 to 12 carbon atoms (the same hereafter).
[0009] In the Japanese Patent Application National Publication No. Hei3-501860, a method is disclosed in which a silazane metal compound is reacted with a perfluorosulfonyl halide compound to obtain an imide compound. In the Japanese Patent Application National Publication No. Hei4-501118, a method is disclosed in which an ionic nitride is reacted with a halogenated sulfonic acid to obtain in imide compound.
[0010] However, the silazane metal compound and the ionic nitride used in each of the above prior art are expensive, and hence the above methods are not an economical production method.
[0011] Also, in the Japanese Patent Application Laid-Open(Kokai) No. Hei8-81436, a method is disclosed in which anhydrous ammonia or a sulfonylamide and a sulfonyl fluoride are reacted with a tertiary amine or a heterocyclic amine, and the reaction product is further reacted with, for instance, a hydroxide containing an alkali metal and an alkali earth metal to produce imide salts.
[0012] In this method, because the product in the first stage is generated as an amine salt, it must be further reacted with an inorganic salt. Also, since a tertiary amine or a heterocyclic amine is used in the reaction, problems concerning work environment caused by the odor and disposal of the amine occur. Moreover, because the anhydrous ammonia is always used, an autoclave as the reactor and a low temperature cooling unit are required. This method is, therefore, unsuitable for mass-production.
[0013] As outlined above, the prior art involves a long reaction step and uses expensive raw materials, and it is hence hard to say that these methods in prior art are industrially acceptable methods.
[0014] In the Japanese Patent Application Laid-Open (Kokai) No. Hei8-81436, anhydrous ammonia, a perfluoroalkylsulfonyl fluoride and a tertiary amine are reacted with each other. To obtain an imide salt, at least two steps are required; and in the reaction, a tertiary amine or a heterocyclic amine is used, causing possibility of pollution of work environment derived from the odor and the like. Further, the product must be reacted with an alkali metal or the like in an aqueous solution in the second step, and at this time, it is necessary to dispose the amine which is freed and distilled together with water, causing increased production costs.
SUMMARY OF THE INVENTION
[0015] It is an object of the present invention to solve these various problems and to produce a sulfonylimide compound industrially easily at a low cost in an efficient manner.
[0016] The inventors of the present application have made earnest studies to accomplish the above object and as a result found that a sulfonylimide compound (represented by the formula (I) MN(SO 2 R f 1 ) (SO 2 R f 2 )) which is free from the foregoing problems can be produced industrially easily at a low cost in an efficient manner.
[0017] More specifically, the present invention comprises a reaction of at least one of the sulfonyl halogenides represented by the formula (II) R f SO 2 X with anhydrous ammonium or an ammonium salt in the presence of fluorine compounds represented by the formula (III) MF.
[0018] In the above-described formulas (I) and (II), M represents any one of Li, Na, K and Cs among alkali metals of group Ia in the periodic table, and X represents either F or Cl among halogen elements of VIIb group in the periodic table. Also, R f in the above-described formula (II) represents the same or identical group as R f 1 or R f 2 in the formula (I).
[0019] The inventors have also found that sulfonylimide compound represented by the formula (I) MN(SO 2 R f 1 ) (SO 2 R f 2 ) can be produced in the mild conditions that anhydrous ammonium is not always used and in only one-step reaction by reacting a sulfonylamide represented by the formula (IV) R f SO 2 NH 2 , at least one of the sulfonyl halogenides represented by the formula (II) R f SO 2 X, and fluorine compound represented by the formula (III)MF with each other.
[0020] Li, Na, K, Rb, Cs and Fr exist as the alkali metals of Ia group in the periodic table. Among these metals, especially any one of Li, Na, K and Cs is selected and used. Therefore, in the case of these metals, the fluorine compounds that are used are LiF, NaF, KF (as KF, any one of calcine-dried KF (cd KF) and spray-dried KF (sd KF) produced by a spray drying method may be used) and CsF
[0021] The reason why Li, Na, K, and Cs are preferred among alkali metals of group Ia in the periodic table is that they are relatively cheap and suitable to produce sulfonylimide compounds industrially easily, at a low cost and in an efficient manner. Especially, K is prominent for the above property among Li, Na, K, and Cs.
[0022] In the present invention, on the other hand, the sulfonylimide compound can be produced by using an ammonium salt. As the ammonium salt in this case, it is desirable to use ammonium fluoride or ammonium hydrogendifluoride. These of either one of these compounds has the advantage that a specific reactor (autoclave) is not required.
[0023] CF 3 SO 2 Cl among sulfonyl halogenides represented by the formula (II) R f SO 2 X, which is sold on the market as a reagent, can be usually handled as liquid because its boiling point is 30° C., relatively high among these kinds of compounds.
[0024] Although “sulfonylimide” and “sulfonylamide” in the present specification should be expressed formally as “sulfonimide” and “sulfonamide”, respectively, both are handled as the same significance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The embodiment of the present invention will be hereinafter explained in detail.
[0026] The object compounds which has been produced in multi-steps in the prior art can be produced in one step by introducing a fluorine compound represented by the formula (III) MF, at least one of the sulfonyl halogenides represented by the formula (II) R f SO 2 X, and anhydrous ammonia or an ammonium salt into an inert solvent and reacting the mixture as shown by the following formula 2, 3, 4, and 5.
[0027] This is due to the basicity of the fluorine compound represented by the formula (III) MF.
[0028] (1) In the case where R f 1 and R f 2 in the formula (I) MN(SO 2 R f 1 ) (SO 2 R f 2 ) are the same or equal to each other:
NH 3 +2R f SO 2 X+6MF→MN(SO 2 R f ) 2 +3MFHF+2MX Reaction Formula 2
[0029] One mol of anhydrous ammonium, 2 mol of at least one of the sulfonyl halogenides represented by the formula (II) R f SO 2 X and 6 mol of a fluorine compound represented by the formula (III) MF are introduced into a reactor and the mixture is reacted in a solvent.
[0030] After completion of the reaction, 2 mol of the by-produced MX and 3 moles of hydrogendifluoride salt MFHF are removed by filtration, and the filtrate is concentrated. The sulfonylimide compound represented by the formula (I) MN(SO 2 R f ) 2 can be thereby produced.
[0031] (2) In the case where R f 1 and R f 2 in the formula (I) MN(SO 2 R f 1 )(SO 2 R f 2 ) are different from each other:
[0032] A sulfonylamide containing the R f 1 group which is produced by a known process shown below is reacted with at least one of the sulfonyl halogenides having a desired R f 2 group. A sulfonylimide compound with the R f 1 group and the R f 2 group are respectively constituted of an objective group can be thereby produced.
[0033] (3) In the case of using an ammonium salt:
(R f 1 SO 2 X)(R f 2 SO 2 X)+7MF+NH 4 F→MN(SO 2 R f 1 )(SO 2 R f 2 )+4MFHF+2MX Reaction Formula 5
[0034] wherein R f 1 and R f 2 are the same or different.
[0035] One mol of an ammonium salt, 2 mol of at least one of the sulfonyl halogenides represented by the formula (II) R f SO 2 X and 7 mol of a fluorine compound represented by the formula (III) MF are introduced into a reactor, and the mixture is reacted in a solvent.
[0036] After completion of the reaction, 2 mol of the by-produced MX and 4 mol of the by-produced hydrogendifluoride MFHF are removed by filtration, and then the filtrate is concentrated. The sulfonylimide compound represented by the formula (I) MN(SO 2 R f 1 ) (SO 2 R f 2 ) can be thereby produced.
[0037] These reactions can occur in a temperature range between about −30° C. and 200° C. At a temperature less than this range, the reaction rate is very low whereas at the temperature exceeding the above range, decomposition of the compounds, solvent and product to be used arises. A more preferable temperature range for the reactions is between 0° C. and 100° C.
[0038] As to the solvent, any solvent can be used without particular limitations as far as it is inert to the reaction materials. For example, ethers such as diethyl ether and tetrahydrofuran, halogenated hydrocarbons such as dichloromethane and dichloroethane, hydrocarbons such as benzene, heptane and hexane and nitrites such as acetonitrile can be used.
[0039] In order to produce various sulfonylimide compounds other than those described above, a sulfonylimide compound obtained by these production methods is made into an acid by using concentrated sulfuric acid and the acid is distilled to thereby synthesize a sulfonylimidic acid [HN(SO 2 R f 1 )(SO 2 R f 2 )]. This acid can be further reacted with a compound selected from hydroxides, oxides, carbonates and acetates of metals corresponding to this acid.
[0040] In this case, fluorine compounds represented by the formula (III) MF to be used in the synthesis of a sulfonylimide compound can be compounded and used.
EXAMPLES
[0041] The present invention will be described in more detail by way of examples, which, of course, do not limit the present invention.
Example 1
[0042] A flask with four necks was charged with 150 ml of acetonitrile, 23.4 g of potassium fluoride and 20 g of trifluoromethylsulfonylamide CF 3 SO 2 NH 2 . The reactor was soaked in a 40° C. hot water bath, and 25.1 g of trifluoromethylsulfonyl fluoride CF 3 SO 2 F was introduced with sufficient stirring. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain potassium bistrifluoromethylsulfonylimide KN(SO 2 CF 3 ) 2 in an amount of 42.7 g. The yield was 99%.
[0043] Next, 42.7 g of this potassium bistrifluoromethylsulfonylimide was added in a flask that was charged with 60 ml of concentrated sulfuric acid, and the mixture was dissolved under heat. Under reduced pressure, 34.6 g of bistrifluoromethylsulfonylimidic acid HN(SO 2 CF 3 ) 2 was distilled by distillation. The yield was 92%.
[0044] Then, 34.6 g of the resulting bistrifluoromethylsulfonylimidic acid was dissolved in pure water and reacted with 4.5 g of lithium carbonate. Excess lithium carbonate was removed by filtration, and the filtrate was concentrated to obtain 34.6 g of lithium bistrifluoromethylsulfonylimide LiN(SO 2 CF 3 ) 2 . The yield was 98%.
Example 2
[0045] An autoclave made of stainless was charged with 200 ml of acetonitrile and 68.3 g of potassium fluoride. The reactor was cooled to −60° C. in a dry ice/methanol bath, and 5 g of anhydrous ammonia was introduced.
[0046] In succession, 90.0 g of trifluoromethylsulfonyl fluoride CF 3 SO 2 F was introduced, and the temperature of the mixture was returned to ambient temperature with sufficient stirring. After that, the reactor was soaked in a 40° C. hot water bath, and the reaction was completed while stirring sufficiently. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain 88.2 g of potassium bistrifluoromethylsulfonylimide KN(SO 2 CF 3 ) 2 . The yield was 95%.
Example 3
[0047] A flask with four necks was charged with 1 liter of methylene chloride, 10 g of ammonium fluoride and 78.4 g of potassium fluoride. The reactor was soaked in a 40° C. hot water bath, and 82.1 g of trifluoromethylsulfonyl fluoride CF 3 SO 2 F was introduced while stirring sufficiently. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain 81.5 g of potassium bistrifluoromethylsulfonylimide KN(SO 2 CF 3 ) 2 . The yield was 95%.
Example 4
[0048] A flask was charged with 300 ml of DMF (dimethylformamide), 30 g of perfluorobutylsulfonyl fluoride C 4 F 9 SO 2 F, 15.1 g of trifluoromethylsulfonylamide CF 3 SO 2 NH 2 and 13 g of sodium fluoride, and the mixure was heated to 100° C. and sufficiently stirred to react. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain 35.1 g of sodium perfluorobutylsulfonyl-trifluoromethylsulfonylimide NaN(SO 2 C 4 F 9 )(SO 2 CF 3 ). The yield was 78.0%.
Example 5
[0049] A flask with four necks was charged with 200 ml of acetonitrile, 12 g of perfluorobuthylsulfonyl fluoride C 4 F 9 SO 2 F, 15.0 g of cesium fluoride, and 0.73 g of ammonium fluoride, and the mixture was heated 50° C. and sufficiently stirred to react. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain 12.5 g of cesium bisperfluorobuthylsulfonylimide CsN(SO 2 C 4 F 9 ) 2 . The yield was 89.3%.
Example 6
[0050] An autoclave made of stainless was charged with 100 ml of dichloromethane, 100 ml of DMF (dimethylformamide) and 30.5 g of lithium fluoride. The reactor was cooled to −60° C. in a dry ice/ methanol bath, and 5 g of anhydrous ammonia was introduced.
[0051] In succession, 100.0 g of trifluoromethylsulfonyl floride CF 3 SO 2 F was introduced, and the temperature of the mixture was returned to ambient temperature with sufficient stirring. After that, the reactor was soaked in a 50° C. hot water bath, and the reaction was run while stirring sufficiently.
[0052] The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure, but only 1.7 g of lithium bistrifluoromethylsulfonylimide LiN(SO 2 CF 3 ) 2 was obtained (the yield was 2.0%).
[0053] Although the amount and percentage yield of the product compound in this case were lower than in the case of other examples, this case is expected to be improved by further studies. Such an improved case should be indeed in the scope of the present invention.
Example 7
[0054] A flask with four necks was charged with 150 ml of acetonitrile, 31.2 g of potassium fluoride, and 10 g of trifluoromethylsulfonylamide CF 3 SO 2 NH 2 were added. The reactor was soaked in a 40° C. water bath, and 11.3 g of trifluoromethylsulfonyl chloride CF 3 SO 2 Cl was introduced while stirring sufficiently. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain 21.4 g of potassium bistrifluoromethylsulfonylimide KN(SO 2 CF 3 ) 2 . The yield was 96%.
[0055] In succession, 21.4 g of potassium bistrifluoromethylsulfonylimide was added in a flask that was charged with 30 ml of concentrated sulfuric acid, and the mixture was dissolved under heat. And then, 15.6 g of bistrifluoromethylsulfonylimidic acid HN(SO 2 CF 3 ) 2 was distilled by distillation under reduced pressure. The yield was 83%.
[0056] The resulting 15.6 g of bistrifluoromethylsulfonylimidic acid was dissolved in the pure water and reacted with 2.1 g of lithium carbonate. Excess lithium carbonate was subjected to filtration, and the filtrate was concentrated to obtain 15.4 g of lithium bistrifluoromethylsulfonylimide LiN(SO 2 CF 3 ) 2 . The yield was 97%.
Example 8
[0057] A flask with four necks was charged with 200 ml of methylene chloride, 10 g of ammonium fluoride, and 110 g of potassium fluoride. The reactor was soaked in a 40° C. water bath, and 91.0 g of trifluoromethylsulfonyl chloride CF 3 SO 2 Cl was introduced while stirring sufficiently. The reaction solution was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain 81.0 g of potassium bistrifluoromethylsulfonylimide KN(SO 2 CF 3 ) 2 . The yield was 94%.
Example 9
[0058] A flask with four necks was charged with 5 g of ammonium fluoride, 143.6 g of cesium fluoride, and 200 ml of tetrahydrofuran. With sufficiently stirring the reactor, 22.8 g of trifluoromethylsulfonyl chloride CF 3 SO 2 Cl was introduced, and then 27.3 g of pentafluoroethylsulfonyl fluoride C 2 F 5 SO 2 F was added. The reaction solution was treated in the same way as Example 2 to obtain 62 g of cesium perfluoroethylsulfonyl trifluoromethylsulfonylimide CsN(SO 2 C 2 F 5 ) (SO 2 CF 3 ). The yield was 99.2%.
Example 10
[0059] In a SUS (stainless)-made autoclave, 200 ml of methylene chloride, 300 ml of DMF (dimethylformamide), 45.6 g of lithium fluoride, and 99.0 g of trifluoromethylsulfonyl chloride CF 3 SO 2 Cl were added. The reactor was cooled to −60° C. in a methanol/dry ice bath, and 5 g of anhydrous ammonia was introduced.
[0060] The reaction mixture was returned to the room temperature while stirring sufficiently, and then the reactor was soaked in a 80° C. water bath, and the reaction was run while stirring sufficiently. Consequently, the reaction solution was treated in the same way as Example 2, but only 0.8 g of lithium bistrifluoromethylsulfonylimide LiN(SO 2 CF 3 ) 2 was obtained (the yield was 0.9%). The amount and yield of the product were considerably lower than the cases of other Examples, however, further improvement may be expected by the future investigations. This invention naturally includes such a case.
Example 11
[0061] In a SUS (stainless)-made autoclave, 200 ml of methylene chloride, 300 ml of DMF (dimethylformamide), 74.1 g of sodium fluoride, and 49.5 g of trifluoromethylsulfonyl chloride CF 3 SO 2 Cl were added. The reactor was cooled to −60° C. in a methanol/dry ice bath, and 5 g of anhydrous ammonia was introduced.
[0062] Consequently, 88.8 g of perfluorobuthylsulfonyl fluoride C 4 F 9 SO 2 F was added, and the reaction mixture was returned to the room temperature with stirring sufficiently. And then, the reactor was soaked in a 80° C. water bath, and the reaction was run while stirring sufficiently. Consequently, the reaction solution was treated in the same way as Example 2, to obtain 18 g of sodium perfluorobuthylsulfonyl trifluoromethylsulfonylimide NaN(SO 2 C 4 F 9 ) (SO 2 CF 3 ). The yield was 13.5%.
[0063] It should be noted that the sulfonylimide compounds obtained in the above examples were respectively confirmed by identifying them using an infrared absorption spectrum.
[0064] As seen from the above description, the production process of the present invention has such an effect that sulfonylimide compounds useful as lithium battery electrolytes and organic synthetic catalysts are produced industrially easily at a low cost in an efficient manner.
[0065] Furthermore, the production process according to the present invention has such an effect that by reacting a sulfonylamide, a sulfonyl fluoride and a fluorine compound with each other, a sulfonylimide compound useful as lithium battery electrolytes and organic synthtic catalysts is produced under a mild condition that anhydrous ammonia is not always used, and in one stage. Also, a specific reactor (autoclave) is not required unlike the case that uses anhydrous ammonia. | A process for producing sulfonylimide compound is represented by the formula (I) MN(SO 2 R f 1 ) (SO 2 R f 2 ) industrially easily at a low cost in an efficient manner comprising reactions of at least one sulfonyl halogenides represented by the formula (II) R f SO 2 X with anhydrous ammonia or an ammonium salt in the presence of a fluorine compound represented by the formula (III) MF, in which X represents either F or Cl among halogen elements of VIIb group in the periodic table, and M represents any one of Li, Na, K and Cs among alkali metals of group Ia in the periodic table, R f 1 and R f 2 , which may be the same or different, respectively represent any one of a straight chain or branched compound of a fluoroalkyl, perfluoroalkyl, fluoroallyl or fluoroalkenyl group having 1 to 12 carbon atoms, and R f in the formula (II) represents the same group as R f 1 or R f 2 in the formula (I). | 2 |
RELATED APPLICATIONS
[0001] This application makes reference to, claims priority to, and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/530,088, entitled “Information Filtering And Processing In A Vehicular Travel Data Exchange Network” (Attorney Docket No. 15236US01), filed Dec. 15, 2003, the complete subject matter of which is hereby incorporated herein by reference, in its entirety.
INCORPORATION BY REFERENCE
[0002] In addition, the applicant hereby incorporates the complete subject matter herein by reference, in its entirety, of U.S. patent application Ser. No. 10/736,819, entitled “Roadway Travel Data Exchange Network” (Attorney Docket No. 15235US01), filed Dec. 15, 2003.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] [Not Applicable]
MICROFICHE/COPYRIGHT REFERENCE
[0004] [Not Applicable]
BACKGROUND OF THE INVENTION
[0005] The amount of travel data that is available for collection and processing at any given moment is substantial. There may be hundreds of thousands of vehicles that may contribute travel related data, such as speed and location, for further processing. However, the efficiency and speed of the information processing may be significantly reduced if travel data from each and every vehicle is continuously considered and further processed. In addition, travel data may be contributed from vehicles, which are actually not actively involved in the traffic flow (for example, parked vehicles and vehicles driving very slowly).
[0006] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0007] Aspects of the present invention may be found in, for example, systems and methods for information filtering in a roadway travel data exchange network. In one embodiment, a travel data processing system may comprise, for example, a communication network. A mobile device may be communicatively coupled to the communication network. A collection system may collect first travel data, where the first travel data may comprise second travel data that is relevant to the mobile device. A filter system may analyze the first travel data to control the flow of at least a portion of the second travel data. A filter device may be communicatively coupled to the communication network and the filter device may comprise at least a portion of the filter system. The mobile device may comprise at least a portion of the filter system. The filter device may comprise a first portion of the filter system and the mobile device may comprise a second portion of the filter system. The filter system may use known roadway information and/or pedestrian velocity estimates.
[0008] In another aspect of the invention, a travel data processing system may comprise a communication network, a mobile traffic participant communicatively coupled to the communication network, the mobile traffic participant associated with travel data, and a filter communicatively coupled to the communication network. The filter may operate on the travel data. The travel data processing system may be associated with a vehicle, where at least one mobile traffic participant may comprise a device installed in the vehicle. The mobile traffic participant may provide the travel data. The filter may use known roadway information and/or pedestrian velocity estimates to perform filtering. The mobile traffic participant may collect and/or transmit at least a portion of the travel data. The mobile traffic participant may receive commands generated in response to the filter. The mobile traffic participant may receive and/or display at least a portion of the travel data. The mobile traffic participant may comprise at least a portion of the filter. The travel data may comprise location information and/or velocity information.
[0009] In yet another aspect of the invention, a method for processing travel data for use with a plurality of mobile travel participants may comprise receiving, from the plurality of mobile travel participants, travel data via a communication network. The travel data may be filtered to obtain filtered travel data. The filtered travel data may represent relevant traffic information. The filtered travel data may be transmitted to at least a portion of the plurality of mobile travel participants. The filtering may comprise selectively eliminating at least one portion of the travel data received, if the at least one portion is determined to be irrelevant based on at least one predetermined criteria.
[0010] These and other features and advantages of the present invention may be appreciated from a review of the following detailed description of the present invention, along with the accompanying figures in which like reference numerals refer to like parts throughout.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0011] FIG. 1 is a diagram illustrating a general embodiment of information filtering in a roadway travel data exchange network, in accordance with various aspects of the present invention.
[0012] FIG. 2A is a diagram of a road intersection illustrating types of information filtering depending on the traffic participant in a roadway travel data exchange network, in accordance with various aspects of the present invention.
[0013] FIG. 2B is a flowchart illustrating a general embodiment of a method for filtering of travel data on a roadway travel data exchange network, in accordance with various aspects of the present invention.
[0014] FIG. 2C is a flowchart illustrating a data collection loop for travel data collection and delayed reporting in a roadway travel data exchange network, in accordance with various aspects of the present invention.
[0015] FIG. 2D is a flowchart illustrating a general embodiment of a method for extrapolating travel data on a roadway travel data exchange network, in accordance with various aspects of the present invention.
[0016] FIG. 3 is a diagram illustrating an embodiment of a roadway travel data exchange network supporting collection, processing and delivery of travel data, in accordance with various aspects of the present invention.
[0017] FIG. 4 is a diagram illustrating a plurality of client systems on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention.
[0018] FIG. 5 is a diagram illustrating a more specific embodiment of a client system on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention.
[0019] FIG. 6 is a diagram illustrating an embodiment of a vehicle interface on the plurality of client systems of FIG. 4 , for example, in accordance with various aspects of the present invention.
[0020] FIG. 7 is a diagram illustrating an embodiment of post-processing information delivery systems on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention.
[0021] FIG. 8 is a diagram illustrating an embodiment of a storage and processing system on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention.
[0022] FIG. 9 is a flowchart illustrating a general embodiment of a method for collection, filtering and delivery of travel data on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Certain embodiments of the present invention relate to filtering of information that is exchanged in a roadway travel data exchange network. In particular, certain embodiments of the present invention enable collection, processing, filtration and delivery of travel data. The travel data may be collected and filtered automatically by a plurality of vehicles that are traveling at a given time. Travel data may also be filtered according to a user-defined criteria upon its communication to a specific vehicle on the roadway travel data exchange network.
[0024] FIG. 1 is a diagram illustrating a general embodiment of information filtering 100 in a roadway travel data exchange network, in accordance with various aspects of the present invention. Travel data 101 may be collected in a roadway travel data exchange network. Due to the substantial volume of traffic-related data that may be collected at a given moment in time, in order to increase efficiency and accuracy in the exchange of information, a filter 103 may be used in order to filter the travel data according to different criteria and methods, and obtain filtered travel data.
[0025] Filtering the travel data may comprise completely removing specific portions of the travel data, or it may involve assigning different weights to travel data received from different vehicles on the roadway travel data exchange network. Rather than completely discarding travel data, a storage and processing system may assign a lower or a higher weight for purposes of making further determinations during the processing of the travel data. In one embodiment, such weighting may be used to adjust for known imprecision in the equipment measuring the travel data. For example, a GPS device may have an accuracy of plus or minus ten feet, and may determine that a first vehicle's location is within five feet of a sidewalk and a second vehicle is in the center of a roadway more than twenty feet from either sidewalk. The storage and processing system may then assign a lower weight to the data reported by the first vehicle, as it is possible that the vehicle is parked near the sidewalk or otherwise not actively participating in the traffic flow. The storage and processing system may assign a higher weight to the data reported by the second vehicle, because it is within the boundaries of the roadway even taking into account the imprecision of the measuring equipment.
[0026] The filter 103 may be software, hardware, firmware, or any combination thereof. For example, in one embodiment of the present invention, the filter 103 may be a software module designed to function according to a specific filtering algorithm.
[0027] FIG. 2A is a diagram of road intersection illustrating types of information filtering depending on the traffic participant in a roadway travel data exchange network, in accordance with various aspects of the present invention. The overhead view of the road intersection 200 illustrates several types of information filtering depending on the type of traffic participant. As discussed more completely below, travel data may be reported from a plurality of traffic participants at any given moment. But not all reported information may be useful. For example, vehicles 201 are parked and not actively involved in the traffic flow at intersection 200 . Travel data from vehicles 201 , therefore, may be filtered and not reported in a roadway travel data exchange network. Vehicle 203 , on the other hand, is actively involved and traveling at the allowed speed limit on intersection 200 . Travel data collected from vehicle 203 may be fully utilized and not filtered. Another vehicle 205 may also be traveling on the intersection 200 close to a sidewalk. Travel data relating to the location of vehicle 205 may be given lower weight. Travel data related to the vehicles 201 may be assigned even lower weight as these vehicles are parked off of the roadway entirely. However, in the event that the airbag of vehicle 205 deployed, travel data relating to such airbag status may be automatically transmitted and utilized in the roadway travel data exchange network as it may indicate a potential accident on that road. A different example of travel data that may be filtered out is traffic-related information received from a pedestrian 207 , who is walking on a sidewalk 209 .
[0028] In order to increase the efficiency in processing the travel data, the storage and processing system on the roadway travel data exchange network may utilize methods to determine whether it has sufficient travel data from a particular location. If so, the storage and processing system can disregard the travel data received for the particular location. If the storage and processing system has insufficient information on the location, then the received travel data may be further processed. In order to achieve this initial filtering test, the storage and processing system may, for example, be configured so that it considers travel data from a first location for a particular given time. If the storage and processing system already has travel data from the first location or a second location that is within a predetermined distance from the first location, and this travel data is relatively recent, then the storage and processing system may use the travel data it already has on the second location and reject any data from the first location. Travel data does not necessarily have to be real-time travel data and from the exact location in order to be relevant. A storage and processing system administrator may determine whether information is relevant or not, i.e. determine the criteria for keeping the travel data. The relevant travel data may be saved at a traffic database at the storage and processing system. After travel data is determined to be no longer relevant, the travel data may be discarded or moved from the traffic database to a historical database at the storage and processing system.
[0029] Referring now to FIG. 2B , there is illustrated a flowchart of a general embodiment of a method for filtering 210 of travel data on a roadway travel data exchange network, in accordance with various aspects of the present invention. The method 210 may be utilized, for example, to filter out travel data based on two filtering criteria—velocity and location. At 211 , the storage and processing system makes the initial determination, as discussed above, of whether it needs travel data from the reporting client and its location. If the storage and processing system has sufficient travel data for such client or location, then no further information is collected. At 212 , the storage and processing system receives travel data, such as location and speed, from a client. In 213 it is determined whether the client system has transmitted velocity and direction. If not, then in 215 velocity and direction is calculated using a prior client system location and the current client system location. The storage and processing system compares, in 217 , the vehicle's velocity to a hypothetical maximum pedestrian speed. If the velocity is greater than the pedestrian speed, then there is high probability that the client is in an active vehicle and its travel data is stored in the traffic database, at 225 . Assuming the client is moving at a speed less than the pedestrian speed, the storage and processing system obtains road information for the current client location, in 219 . In 221 it is determined whether the client is located on a known roadway. If it is not, then in 223 the client travel data is discarded. If client is located within a known road, then the travel data is saved in the traffic database, in 225 .
[0030] The initial filtering step 211 , as well as the filtering steps 217 and 221 , may be performed by both or either of the storage and processing system and the client system. For example, the initial filtering of 211 may be performed by the storage and processing system, and the subsequent filtering at 217 and 221 may be performed by the client system, i.e. the client may measure location and velocity and may not transmit any data to the storage and processing system if the speed is less than the pedestrian speed and the location is not within a known roadway. The client system may, independently or with assistance of the storage and processing system, determine whether it is on a road and/or is moving at a speed greater than a maximum pedestrian speed, and only report travel data to the storage and processing system if indeed it is traveling on a road. In this way, the amount of communication overhead needed to report relevant travel data is substantially reduced. The determination of whether filtering is performed by the storage and processing system and/or by the client system depends on considerations such as power management, available storage resources and bandwidth, and costs.
[0031] In a different embodiment of the present invention, a travel data filtering method may comprise only several of the filtering criteria utilized in method 210 . For example, a client system may only determine its geographic location and transmits that information to a storage and processing system. Filtering of the client's travel data may then be accomplished by utilizing only steps 219 and 221 , by comparing the geographic location information received from the client system with a database with location information for roadways. If the client system is located in an area identified by the database as a roadway, then the storage and processing system may keep the information. If the identified area is not recognized as a roadway, then the received travel data may be discarded. Since the client is not on a known road, its reported travel data will be filtered out.
[0032] The methods for filtering travel data by location may also take into account the accuracy of both the location information and the roadway information. For example, if the location information is obtained by a given vehicle with an accuracy of +/−10 feet, and the roadway database provides location information for roadways with accuracy of +/−20 feet, then the storage and processing system may discard travel data from vehicles located 30, or more, feet from a known roadway. It may assign lesser weight to vehicles located within 30 feet of the sides of a roadway, and greater weight to vehicles located inside a roadway greater than 30 feet away from either side of the roadway.
[0033] FIG. 2C is a flowchart illustrating a data collection loop 230 for travel data collection and delayed reporting in a roadway travel data exchange network, in accordance with various aspects of the present invention. The storage and processing system may be continuously updated with travel data. However, in order to reduce the transmission and processing overhead on the storage and processing system and all involved client systems, it may be more efficient if each client does not continuously update the storage and processing system. A client system may collect travel data, buffer it and transmit the buffered travel data to the storage and processing system only at a predetermined reporting interval. A data collection loop 230 may be implemented on the client system. Travel data is collected by the client system at 231 and is then buffered by the client system at 233 . At query 235 , it is determined whether the reporting interval has occurred. If it has occurred, then the buffered travel data is communicated to the storage and processing system. If it has not occurred, then collection of travel data resumes at 231 .
[0034] In an embodiment of the present invention, the client system may report only changes in the travel data within a predetermined range. For example, a client system may report its speed at a given moment. However, if the speed is being maintained constant for a certain period of time, the client system may not initiate any reporting to the storage and processing system. However, if the speed changes within a predetermined range (e.g., speed increases with 5 mph), then the client system will report that change to the storage and processing system. Similar filtering criteria may be applied with regard to other types of travel data.
[0035] FIG. 2D is a flowchart illustrating a general embodiment of a method 240 for extrapolating travel data on a roadway travel data exchange network, in accordance with various aspects of the present invention. Method 240 may be used when the storage and processing system does not have enough travel data for a certain location of interest, location B, but the storage and processing system has sufficiently reliable travel data for surrounding locations A and C. At 241 , the storage and processing system may receive travel data associated with locations A and C. At 243 , the storage and processing system receives a request for travel data for location B, situated between A and C. At 245 , travel data for locations A and C is extrapolated in order to receive extrapolated travel data for location B. At 247 , the extrapolated travel data for location B is reported.
[0036] FIG. 3 is a diagram illustrating a roadway travel data exchange network 300 supporting collection, processing and exchange of travel data, in accordance with various aspects of the present invention. The roadway travel data exchange network 300 comprises a communication infrastructure 315 , pluralities of client systems 303 and 319 , supporting collection systems 305 , and a storage and processing system 317 . The plurality of client systems 303 comprise collection systems 311 and retrieval/post-processing systems 313 . However, the plurality of client systems 319 comprise retrieval/post-processing systems 313 and no collection systems 311 .
[0037] The plurality of client systems 303 collect travel data and deliver the collected data to the storage and processing system 317 via the communication infrastructure 315 . The storage and processing system 317 also receives collected travel data from the supporting collection systems 305 . These collection processes occur both periodically and in real time.
[0038] To support the pluralities of client systems 303 and 319 , the storage and processing system 317 correlates, combines and otherwise processes the collected travel data to generate processed data and instructions. The processed data and instructions are delivered to the pluralities of client systems 303 and 319 via the communication infrastructure 315 for post-processing. Post-processing by the pluralities of client systems 303 and 319 may include, for example, communicating the processed data to the user, further computation, control and storage.
[0039] Some of the pluralities of client systems 303 and 319 are installed in roadway vehicles. Others of the pluralities of client systems 303 and 319 are portable devices that may be carried inside roadway vehicles. Yet other of the pluralities of client systems 303 and 319 are neither installed nor carried inside roadway vehicles. The plurality of client systems 303 , installed or associated with roadway vehicles: (1) collect travel data via the collection systems 311 ; (2) exchange collected travel data with the storage and processing system 317 , the client systems 319 , others of the client systems 303 , and the supporting collection systems 305 ; and (3) post-process travel data retrieved from the storage and processing system 317 , the client systems 319 , others of the client systems 303 , and the supporting collection systems 305 . Although the plurality of client systems 319 do not perform collection, they also post-process such retrieved and received travel data via the communication infrastructure from the systems 317 , 303 , 305 , and other client systems 319 .
[0040] The pluralities of client systems 303 and 319 may be categorized as multi-purpose or dedicated client systems. The characteristic feature of a multi-purpose client system is that it may perform various functions related to the travel data as well as additional functions that are not related to travel data. A dedicated client system can only perform functions related to the travel data.
[0041] Collection of travel data by the plurality of client systems 303 is accomplished in several ways. Some of the plurality of client systems 303 receive instructions from the systems 317 , 319 and 305 and from others of the client systems 303 to deliver, or collect and deliver, certain travel data. Any of the plurality of client systems 303 may be pre-configured or instructed to regularly collect and deliver such travel data without awaiting specific requests. Such “pre-arranged” collection and delivery can occur continuously or as travel data becomes available. The collection and delivery process performed by each of the plurality of client systems 303 may be activated or deactivated via the communication infrastructure or through direct interaction with the client systems 303 . The retrieval and post-processing of the plurality of client systems 303 may be similarly activated or deactivated.
[0042] Another way for collecting information is for the plurality of client systems 303 to automatically initiate collection (and subsequent delivery) of travel data. For example, upon sensing motion, periodic collection and delivery might be automatically initiated by the client systems 303 . Such client system 303 might also periodically collect and deliver the moving vehicle's geographic location, its speed, direction and other travel data. Alternatively, the plurality of client systems 303 may be triggered manually to initiate collection and/or delivery of travel data.
[0043] After processing travel data delivered by one of the plurality of client systems 303 , the storage and processing system 317 may return processed travel data and/or instructions to the delivering one of the plurality of client systems 303 . In addition, the storage and processing system 317 delivers the processed travel data and related instructions to others of the pluralities of client systems 303 and 319 . For example, processed travel data may be delivered to one of the client systems 303 in response to travel data collected from another of the client systems. Any of the pluralities of client systems 303 and 319 that receive the processed travel data or related instructions may forward same or post-process and forward post-processed data or instructions to yet others of the pluralities of client systems 303 and 319 .
[0044] The roadway travel data exchange network 300 is enhanced with capability of receiving additional information that may relate to travel. Such additional travel-related information may be collected by supporting collection systems 305 . For example, various governmental agencies or news organizations will have the capability to contribute travel-related data. Governmental agencies that may contribute travel-related data to the roadway travel data exchange network include, for example, a local city police department, a state police department, a sheriff's department, a highway patrol, and a meteorological agency. The travel-related data may be collected by using a client system 303 , in a similar manner as discussed above. The travel-related data may comprise, for example, information about the number of vehicles that pass through a certain part of a road, vehicle speed, and direction of travel. If the travel-related data is collected by the governmental agency representative using a device similar to a client system 303 , the device may automatically collect and transmit the travel-related data to the storage and processing system 317 for further processing. The governmental agency representative may also collect travel-related data by observation and then enter it into the roadway travel data exchange network by transmitting it directly to the storage and processing system 317 . For example, a police officer may be monitoring a busy road intersection and may observe a traffic accident. As a result of the accident, all lanes of the road may become blocked and traffic flow may quickly deteriorate. The police officer may then transmit to the storage and processing system 317 his exact location and the fact that the specific road has been blocked in both directions due to a traffic accident.
[0045] The supporting collection systems 305 may comprise, for example, weather-related data collection systems. The weather-related data may be automatically collected by weather sensors placed at key intersections, highways, or roads. The weather-related data may include, for example, outside temperature, precipitation amount and emergency weather data (such as information for an approaching tornado). Certain weather-related data may be entered into the roadway travel data exchange network and transmitted to the storage and processing system 317 via a client system 303 . The supporting collection systems 305 may also comprise a meteorological data collection system that delivers travel data in the form of weather information to the storage and processing system 317 .
[0046] The supporting collection systems 305 also deliver travel data directly to the client systems 303 and 319 for post-processing via the communication infrastructure 315 . Instructions may also be delivered by the supporting collection systems 105 to the storage and processing system 317 or the client systems 303 and 319 via the communication infrastructure 315 .
[0047] The pluralities of client systems 303 and 319 have display capabilities so that collected and processed travel data may be displayed for a user as part of the post-processing functionality of the retrieval/post-processing systems 313 . For example, some of the plurality of client systems 303 transmit geographic location (corresponding to either the location of the client system or any other selected location) to the storage and processing system 317 , requesting related weather and speed information. In response to such request, the storage and processing system 317 uses the geographic location to access stored travel data to produce the related weather and speed information for delivery to the requesting client system.
[0048] The communication infrastructure 315 may comprise a single communication network or a plurality of communication networks. Such networks may comprise wired and wireless portions. More specifically, collection of information and transmission of the collected information via the communication infrastructure 315 may be accomplished by using wireless transmission methods, such as General Packet Radio Service (GPRS) or Wideband Code Division Multiple Access (WCDMA). Collection and transmission on the communication infrastructure 315 may also be accomplished using radio, 802.11 network, ultrawideband communication, or any other means that allow sufficient freedom of movement. Delivery of information on the communication infrastructure 315 can be accomplished by using the same wireless transmission methods that are used for transmission of the collected information. In addition, delivery via the communication infrastructure 315 may be accomplished by using a cable infrastructure, a satellite network infrastructure, a digital subscriber line (DSL) infrastructure, an Internet infrastructure, an intranet infrastructure, a wired infrastructure, a closed communication infrastructure, and a local area network. Complimentary technology exists on the roadway travel data exchange network 300 , including the storage and processing system 317 , and the client systems 303 and 319 in order to use the communication infrastructure and process travel data on the roadway travel data exchange network.
[0049] In an embodiment of the present invention, the roadway travel data exchange network may comprise a plurality of storage and processing systems. For example, in order to increase efficiency in the exchange of information, a storage and processing system may be placed near several major roads or intersections so that travel data may be reported to the storage and processing system which is closest to the reporting vehicle. The plurality of storage and processing systems may be connected together, or to a main storage and processing system, via the communication infrastructure 315 . The plurality of processing systems may each be deployed to provide different services or portions of an overall service offering. In such cases, the client systems may employ post-processing that correlates or otherwise combines the services or service information delivered by the plurality of processing systems.
[0050] In another embodiment of the present invention, a plurality of client systems 303 may be utilized, as well as a plurality of client systems 319 . Travel data that is collected by one or more of the collection systems 311 on the client systems 303 may be transmitted to, and processed by, a storage and processing system. Subsequent results may be utilized by the same client systems 303 which collected the travel data, or by other client systems 303 . The same results, however, may also be utilized by one or more of the retrieval/post-processing systems 313 on the plurality of client systems 319 .
[0051] FIG. 4 is a diagram illustrating a plurality of client systems on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention. The plurality of client systems 401 may comprise one or more of the multipurpose client systems 403 and/or one or more of the dedicated client systems 405 . More specifically, the multipurpose client system 403 may be, for example, one or more of a personal digital assistant (PDA) 407 , a cellular phone 409 , a laptop computer 411 , and a global positioning system (GPS) device 413 . The multipurpose client system 403 is enabled to collect, transmit, receive and deliver travel data. However, the multipurpose client system 403 may perform additional functions as well. For example, the PDA 407 may store and recall personal information. The dedicated client system 405 may only perform functions related to the travel data. The dedicated client system 405 may comprise a client system 415 physically embedded (“hardwired”) in the vehicle. A dedicated client system 405 may also be designed as a portable dedicated unit 417 .
[0052] Referring now to FIG. 5 , there is illustrated a more specific embodiment of one of the client systems 401 in the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention. In order to accomplish efficient exchange of travel data, the client system 401 comprises a user interface 503 , a processor 511 and a communication interface 513 .
[0053] The client system 401 is adapted to collect, transmit, receive and deliver travel data. Where the client system 401 is “dedicated” or embedded in a vehicle, a vehicle interface 515 supports the collection of travel data related to the vehicle in which it is embedded. Such travel data may comprise, for example, information on the vehicle speed, tire pressure, airbag deployment, etc.
[0054] In the present embodiment, geographic location information of a vehicle is determined through location circuitry. If the location circuitry is present in the vehicle in which the client system is located, then the location circuitry will deliver the geographic location information to the client system 401 via the vehicle interface 515 . However, if the vehicle lacks location circuitry, the client system 401 may comprise location circuitry within a location interface 516 . For example, in one embodiment, the location interface 516 comprises GPS (Global Positioning System) circuitry. In other embodiments, geographic location may be determined by any sufficiently reliable mechanisms for determining location, such as mechanisms employing triangulation techniques. The GPS circuitry may also assist in determining speed and direction of a vehicle if such travel data may not be collected directly via the vehicle interface 515 .
[0055] The user interface 503 comprises a keyboard 507 , which may be used to enter travel data manually or otherwise interact with the client system 401 . For example, the keyboard might be used to request travel data from the storage and processing system 317 of FIG. 3 . Of course, any other user input devices such as a touchscreen, mouse, buttons, dials or switches might also, or alternatively, be used.
[0056] Travel data which is delivered to the client system 401 is displayed on a display 505 . The client system 401 may also provide for audible notification of the received travel data via speakers 509 . Information which is entered or received via the client system 401 is processed by the processor 511 . A communication interface 513 communicatively couples the client system 401 with the communication infrastructure so as to provide access to the storage and processing system 317 , for example. Through the communication interface 513 , processed, post-processed and collected travel data is exchanged. For example, the storage and processing system 317 delivers processed travel data to the client system 401 for display and audible output on the display 505 and speakers 509 respectively.
[0057] The processor 511 may perform filtering of the travel data by utilizing the filter 512 . The filter 512 may be software, hardware, firmware, or any combination thereof. In addition, the filter 512 may be embedded in the client system 401 , or it may be communicatively coupled to the client system 401 .
[0058] Referring now to FIG. 6 , there is illustrated a diagram of an embodiment of a vehicle interface on the plurality of client systems of FIG. 4 , for example, in accordance with various aspects of the present invention. The vehicle interface 515 provides functionality for collecting travel data that is related to the vehicle in which it is embedded. Travel data that may be collected by a client system may include, for example, a geographic location, a speed, a direction, an airbag status, an engine status, an outside temperature, a deployment status of vehicle brakes, a road precipitation status, a rollover status, a tire pressure status, a deployment status of an acceleration pedal, and a fuel level.
[0059] Geographic location information of a vehicle may be determined, for example, through a GPS, such as the GPS 413 of FIG. 4 . GPS may also assist in determining speed and direction of a vehicle if the client system is not embedded and such traffic data may not be collected directly via the vehicle interface 515 . Speed and direction of a vehicle may be determined by measuring the vehicle's location with a GPS several times over a specific time interval. The traveled distance and time may then be calculated and may be used to determine speed and direction.
[0060] Referring now to FIG. 7 , there is illustrated an embodiment of post-processing information delivery systems on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention. Various post-processing information delivery systems 700 may be utilized in the retrieval/post-processing systems 313 of FIG. 3 . Travel data communicated from the storage and processing system 317 may, for example, be delivered to a telephone 701 , a computer 703 , a television 705 , a radio 707 , a satellite 709 , or a road sign display 711 .
[0061] The telephone 701 may, for example, be a dedicated telephone line. Users of the roadway travel data exchange network may dial this dedicated phone line and hear a recorded message with specific travel data. The contents of the recorded message may be periodically updated with new travel data. Several post-processing information delivery systems may be utilized at the same time. For example, information about an accident may be displayed on a road sign display 711 , while at the same time a radio 707 may broadcast information on alternate routes that may be utilized around the accident site.
[0062] Referring now to FIG. 8 , there is illustrated an embodiment of a storage and processing system on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention. The storage and processing system 317 comprises a communication interface 805 for communicating with the roadway travel data exchange network via the communication infrastructure 315 of FIG. 3 . Travel data received by the storage and processing system 317 via the communication interface 805 is processed by a processor 803 , and is subsequently stored in storage 807 . The storage 807 comprises several databases, which are associated with the type of travel data they contain. For example, the storage 807 comprises a traffic database 809 , a roadways database 811 , and a weather database 813 . The traffic database 809 stores all roadway travel data related to traffic. The roadways database 811 stores information about the specific geographic location of a roadway network and specific roadway characteristics, such as type of road, length, maximum allowed speed, number of lanes, etc. The weather database stores the weather-related data that is received, for example, from supporting collection systems 305 of FIG. 3 . The storage and processing system 317 may also comprise a user interface 801 , which may allow an authorized user to directly input into the storage and processing system traffic-related, roadway-related, or weather-related information, or to edit existing information.
[0063] In addition, the processor 803 may perform filtering of the travel data by utilizing the filter 804 . The filter 804 may be software, hardware, firmware or any combination thereof. In addition, the filter 804 may be embedded in the storage and processing system 317 , or it may be communicatively coupled to the storage and processing system 317 .
[0064] In an embodiment of the present invention, the roadway travel data exchange network may comprise a plurality of storage and processing systems. For example, in order to increase efficiency in the exchange of information, a storage and processing system may be placed near several major roads or intersections so that travel data may be reported to the storage and processing system which is closest to the reporting vehicle. The plurality of storage and processing systems may be connected together, or to a main storage and processing system, via the communication network infrastructure 315 .
[0065] In another embodiment of the present invention, information filtering on the roadway travel data exchange network 300 may be accomplished by a plurality of filters, functioning in accordance with various aspects of the present invention. A filter 512 in a client system 401 in FIG. 5 , for example, may utilize user-defined criteria for filtering of travel data transmitted or received by the client system 401 . The filter 512 on the client system 401 may, for example, be programmed to deliver only certain type of travel data (e.g., the location of gas stations within a 5 mile radius of the current location of the client system). The filter 512 may also be programmed to filter out all travel data if the client system is not on a known roadway, or if the client system is not in a moving vehicle. Another filter 804 in FIG. 8 may, at the same time, be located on the storage and processing system 317 and may additionally filter travel data according to other filtering criteria.
[0066] The terms “filter” and “filtering” as utilized herein do not refer to filtering of noise from a received signal, for example. The present invention may not be limited by any such definitions. In one aspect of the invention, filtering may comprise screening all, or selected portions of, travel information. Travel information screening may be initiated prior to transmission of travel information or after transmission of travel information. Accordingly, travel information screening may be initiated at the transmitting side and/or at the receiving side, respectively. In this manner, screening/filtering of travel information may alter amount and/or content of future travel information transmissions, or prevent future travel information transmissions altogether.
[0067] In one aspect of the invention, filtering of travel information may be programmable. For example, a travel data processing system in accordance with the present invention may be adapted to communicate and/or receive one or more travel information filtering instructions indicating one or more filtering preferences. The filtering preferences may comprise time of filtering, duration of filtering, type of travel information to be filtered, and/or travel participants affected, for example. Accordingly, aspects of the travel data processing systems may be altered and/or programmed automatically, or via a user intervention.
[0068] Referring now to FIG. 9 , there is illustrated a general embodiment of a method 900 for collection, filtering and delivery of travel data on the roadway travel data exchange network of FIG. 3 , for example, in accordance with various aspects of the present invention. At 901 , travel data is requested by a storage and processing system from a client system on a roadway travel data exchange network. At 903 , a multipurpose client system or a dedicated client system collects the requested travel data. The travel data is then filtered, at 911 , by a filter, such as a filter embedded in the client system, prior to the client system transmitting it to the storage and processing system. The client system then transmits, at 905 , the collected travel data to the storage and processing system via a communication network infrastructure. At 907 , the travel data is processed by a processor at the storage and processing system. After the travel data is processed by the processor it may be stored in a storage provided at the storage and processing system. As an alternative to the filtering at 911 by the embedded filter the travel data may be filtered, at 913 , by the storage and processing system (for example, a filter such as filter 804 of FIG. 8 may be used). At 909 , the filtered travel data is delivered from the storage and processing system to the same client system or to another client system for post-processing.
[0069] While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims. | A traffic monitoring system includes one or more processors operable to collect location data from a third-party network having a mobile user, weight at least one element of the location data based on reliability, and generate traffic speed data at a roadway location based on the weighted data. The third-party network is one of a mobile communication network, a computer network, a television network, a radio network, and a road sign display network. The one or more processors are operable to deliver the traffic speed data at the roadway location to an alternate third-party network. The alternate third-party network is one of a mobile communication network, a computer network, a television network, a radio network, and a road sign display network. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a sensor, and in particular to a force sensor. Force sensors are more important than other types of sensor, as they may be readily adapted to measure other physical properties.
In a known force sensor described in British Patent Application No. GB 2146120A, a light source produces light pulses which are used to induce resonance in a body by means of the photo-acoustic effect in which each of the incident light pulses causes alternate heating and cooling of the body at the frequency of the pulsed light source. The resonance frequency at which the body vibrates depends on a force applied to it. An advantage of this kind of force sensor is that no electrical connection between the vibrating body and the power source is required. The absence of electricity in sensors employing optically driven vibrating bodies is particularly advantageous when the sensors are used in environments where the presence of electricity is hazardous.
A disadvantage of this known type of force sensor is that it is very difficult to lock the optical pulse frequency on to the vibrational resonance frequency when that frequency is continually varying due to changes in the applied force. A separate technique is necessary to monitor the amplitude of vibration of the body or the phase of its vibrational displacement relative to the optical pulses, to provide feedback between the optical pulse frequency and the vibrational resonance frequency. The optical pulse frequency can then be automatically adjusted to follow any change in the resonance frequency, and hence keep the two locked together.
SUMMARY OF THE INVENTION
The present invention seeks to provide an improved sensor in which this difficulty is reduced.
According to a first aspect of this invention a sensor includes: a body having a resonance frequency which is dependent on the nature of the applied force; a light source arranged to continuously illuminate the said body; a modulating means which causes the amount of light absorbing by the body to be dependent on its vibrational displacement causing it to oscillate at a resonance frequency; and means for determining the resulting resonance frequency.
According to a second aspect of this invention a sensor includes: a body having a resonance frequency which is dependent upon the nature of an applied force; a light source arranged to continuously illuminate the body to cause it to vibrate at a resonance frequency due to a photothermal effect in which a portion of the body alternately expands and contracts resulting from a variation in the intensity of light illuminating the said body as the body expands and contracts; and means for determining the resulting resonance frequency.
The term `light` when used in this specification is to be interpreted as including the range of electromagnetic radiation from infra-red to ultra-violet inclusive. Thus the body goes into self-oscillation when the light falls upon the body.
In one embodiment of the invention, a Fabry-Perot interferometer, whose light transmissive properties depend on the distance between two partially reflective surfaces, is interposed between the light source and the body such that the distance varies as the body expands and contracts, thereby causing the intensity of light illuminating the body to vary as the body expands and contracts.
In another embodiment of the invention the surface of the body which is illuminated by the light source is selectively masked such that part of it is reflective, and part of it is absorptive, and as the body expands and contracts, the proportion of the absorptive part exposed to illumination varies, thus varying the intensity of light illuminating the body.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further described by way of example, with reference to the accompanying drawings, in which:
FIG. 1 illustrates schematically a vibratable beam which may be used in a sensor according to this invention,
FIG. 2 shows in graphical form the relation between optical transmission of the Fabry-Perot interferometer and the mirror separation;
FIG. 3 illustrates a photothermal oscillator sensor in which a Fabry-Perot interferometer is used to vary the intensity of the incident light;
FIG. 4 illustrates schematically an alternative embodiment of a photothermal oscillator sensor in which selective masking is used to vary the intensity of the incident light;
FIG. 5 illustrates in more detail the principle of selective masking feedback technique used in the embodiment illustrated in FIG. 4, and
FIG. 6 illustrates another embodiment of the invention, also using the selective masking technique.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a rectangular beam 1 made from a rigid material such as aluminium or glass or a crystalline material such as quartz is supported on two comparatively massive supports 2 and 3 such that it can vibrate freely in a flexural mode in the plane of the paper. One surface 4 of the beam 1 is optically polished to produce a surface which is partially optically reflective and partially absorbing. A mirror 5 is placed in close proximity to the surface 4 comprises an optically polished flat glass plate 6 with a surface 7 having a partially transparent reflective coating or the side closest to the beam 1. The mirror is positioned so that its reflective surface is accurately parallel to the surface 4 and separated from it by a few wavelengths of the light with which it is intended to be used. The combination of the two surfaces 4 and 7 constitutes an optical interferometer of the Fabry-Perot type.
A Fabry-Perot interferometer is a device in which monochromatic light passing through a pair of plane-parallel, partially reflective surfaces, is strongly transmitted when the distance between the surfaces is exactly equal, or close, to an integral multiple of an optical half wavelength, and is strongly reflected when the distance between the reflective surfaces is substantially different from an integral multiple of an optical half wavelength.
Referring to FIG. 2, curve 40 shows graphically how the optical transmission of the Fabry-Perot interferometer varies periodically as a function of the distance between the reflective surfaces. When the beam 1 (FIG. 1) is stationary, the distance between the surfaces is represented by point 41, and results in an optical transmission represented by point 42. When the beam 1 (FIG. 1) is caused to vibrate, the distance between the surfaces will vary sinusoidally with time, as indicated by curve 43, the optical transmission will vary substantially sinusoidially as indicated by curve 44. This variation indicated by curve 44 is in phase with the periodic variation of optical transmission represented by curve 40.
Referring again to FIG. 1, when mirror surface 7 is illuminated by a monochromatic beam of light 8, in a direction perpendicular to the mirror surface 7, the interferometer formed by surfaces 4 and 7 transmits the light if the mirror separation is initially close to an integral multiple of an optical half wavelength. Mirror surface 4 is composed of a partially reflective material such as a vacuum evaporated aluminium layer sufficiently thick to ensure that any light not reflected from the surface 4 is totally absorbed within the layer. The intensity of light beam 8 is sufficiently great to cause appreciable heating within the aluminium layer, which is immediately transferred by thermal conduction to the surface of the beam 1. The resulting thermal expansion of the surface layer of beam 1 causes the beam 1 to bend outwards in a direction which reduces the gap between mirror surfaces 4 and 7. The change in the separation distance of the mirror surfaces 4 and 7 causes a reduction in the amount of transmitted light because the separation has changed. This results in the heating of aluminium layer 4 and therefore of the surface of beam 1 being substantially reduced so that the surface of the beam cools and the corresponding thermal contraction causes the beam to return towards its original position. Having returned, the heating of the surface by the transmitted light increases again and the cycle repeats itself. The thermal capacity and thermal conductivity of beam 1 are such that the time required for the beam temperature to reach equilibrium when it is heated and cooled is much larger than the periods of the vibrational cycle, so that the surface temperature of beam 1 is approximately proportional to the time-integral of the optical power transmitted through the interferometer. When the beam is vibrating sinusoidally in a flexural mode, the transmitted power is modulated sinusoidally in phase with the beam displacement. The resulting modulation of the surface temperature of beam 1 also varies sinusoidally but it lags in phase behind the beam displacement by approximately 90 degrees because it is proportional to the time-integral of the transmitted power.
The mechanical bending force driving the vibration is proportional to the sinusoidal component of the temperature rise in the surface, and therefore this force is 90 degrees out of phase with the beam displacement. It is well known that when a mechanically resonant structure is driven by a sinusoidally modulated force, the force and displacement are 90 degrees out of phase when the driving frequency is equal to the mechanical resonance frequency, so in this case the relative phase of driving force and displacement are correct for maintaining oscillation at the resonance frequency. Provided that the mechanical energy gained by the beam during the heating part of the vibrational cycle is greater than the energy lost during the vibrational cycle as a whole due to internal mechanical friction in beam 1 and acoustic radiation to its surroundings, the amplitude of vibration will increase on successive cycles causing beam 1 to oscillate in a self-sustaining manner. The amplitude of vibration will continue to increase until the non-linear displacement versus transmission characteristic of the interferometer shown in FIG. 2 causes the sinusoidal component of drive power to be limited. The vibration amplitude will then stabilise at a value for which the power gained from the light source and the power lost from the beam vibration are in equilibrium.
For oscillation to be self-starting and self-sustaining, two conditions need to be met:
(a) the separation of mirror surfaces 4 and 7 should initially be such that absorption of heat by beam 1 causes it to move in a direction which causes a reduction in optical power transmitted by the interferometer, and
(b) the light power illuminating beam 1 should be sufficient to ensure that the mechanical energy gained by the beam during each cycle from the illumination is greater than the energy lost per cycle. The minimum energy required to achieve this is referred to as the threshold power for the oscillation.
The light reflected from the interferometer mirror surfaces when the beam 1 is self-oscillating is amplitude modulated at the vibration frequency. The beam vibration frequency may therefore be conveniently measured by directing the reflected light onto a photodetector (not shown in FIG. 1) and measuring the frequency of the resulting electrical signal. The device may be used as a force sensor by applying a force to beam 1 along its axis through the mountings 2 and 3 and measuring the resulting change in oscillation frequency measured by the photodetector.
In order that the threshold power is comparable with the power available from commonly used light sources such as light-emitting semi-conductor diodes and laser diodes, the dimensions of the beam 1 must be small. Typically, the beam 1 is approximately 3 mm long, 0.05 mm wide and 0.02 mm thick. A beam of these dimensions will have a resonance frequency of about 20 kHz.
Small structures of this type can readily be fabricated by micro-mechanical techniques.
FIG. 3 shows a photothermal oscillator sensor employing a vibratable beam fabricated by micro-mechanical techniques. A vibratable beam 1 of approximately rectangular cross-section is fabricated by chemical etching from a plate of silicon 9 which may be 0.5 mm thick overall. The beam, which has dimensions comparable with those mentioned above, is attached to the body of the plate at each end but is otherwise free to vibrate in a direction perpendicular to the plate surface 38. A middle portion 10 of the of beam 1 which is coplanar with the surface of plate 9, is optically polished, although alternatively an optically flat metallic film such as a thin aluminium layer may be deposited on the middle portion 10 of the beam 1 to enhance its reflectivity. An optical fibre 11 is positioned close to the surface of beam 1 near to is middle portion 10. The fibre 11 has an optically polished end 12 which is flat and perpendicular to the fibre axis and is coated with a partially reflective metal coating such as a thin aluminium layer or a partially reflective multi-layer dielectric coating. The end of the fibre is positioned so that it is parallel to the surface of the beam 1, and opposite the middle portion of the beam surface 4, and is separated from it by a few optical wavelengths to constitute the Fabry-Perot interferometer. This can be achieved by mounting the end of the fibre in an accurately machined hole in a separate silicon block 13 which is bonded onto the surface of silicon plate 9. Silicon block 13 has a recess machined or etched into the bonded surface to ensure that the vibrating beam 1 does not touch the surface of block 13 during the course of its oscillation. It is advantageous to make block 13 from the same material as plate 9 and beam 1 and with the same crystallographic orientation so that differential thermal expansion between the components does not occur when the temperature changes, causing deformation of the structure. The exact separation between the end of reflective fibre 12 and the reflective surface of the beam 1, is adjusted to be close to an integral number of a half wavelength of the light illuminating the optical fibre. This allows light energy passing from the fibre into the interferometer space between the reflective surfaces of the middle portion 10 and the end 12 to be greatly absorbed by the surface of beam 1.
Optical fibre 11 may be of a multi-mode type, that is to say having a sufficiently large core diameter (such as 50 micrometers) to allow light to propagate along it in a zig-zag fashion with a direction of propagation at an angle to the fibre axis, but is preferably of a single-mode type with a core diameter of typically 3-6 micrometers which allows light to propagate in a direction parallel to the axis only and suppresses zig-zag modes. The use of single-mode fibre ensures that light emerging from the fibre end propagates in a direction perpendicular to the reflective surfaces of the middle portion 10 and the end 12 and so is reflected from the surfaces in a perpendicular direction. The avoidance of off-axis modes which may be introduced by the use of multi-mode fibre, ensures that the intensity modulation of light absorbed in the reflective surface of middle portion 10 is a maximum.
Light is generated by a continuous light source 14 which is preferably a light-emitting semiconductor diode or a laser diode emitting over a narrow range of wavelengths so as to constitute a substatially monochromatic source of light. The light source is powered by a continuous current source 15. Light from source 14 is focussed into an approximately parallel beam by lens 16. The approximately parallel beam then passes through a semi-reflecting plane mirror 17 and is refocussed by lens 18 onto the end of optical fibre 11. The light power emitting into fibre 11 is greater than the threshold power for oscillation defined previously, which may be of the order of 1 milliwatt for a structure of the dimensions defined above. The beam 1 then oscillates spontaneously in its fundamental flexural mode provided that the light power is not sufficiently great to exceed the oscillation threshold for higher order flexural modes.
Provided that beam 1 is illuminated symmetrically about its mid-point, only symmetrical flexural modes will be excited. It can be shown theoretically that the threshold power for exciting the next highest symmetrical flexural mode above the fundamental is approximately 30 times greater than that needed to excite the fundamental mode itself. In practice, therefore, the photothermal oscillator can be easily constrained to oscillate in the fundamental mode only, by adjustment of the input power.
When beam 1 is oscillating, the reflected light returned to the optical fibre 11 by the interferometer will be modulated in intensity at the oscillation frequency. The return light passing through the fibre is reflected by semi-reflecting plane mirror 17 onto lens 19 which focusses it onto photodetector 20 which may be a silicon photovoltaic cell. Photodetector 20 produces an output voltage modulated at the oscillation frequency which is measured by a frequency counter 21.
The photothermal oscillator as described may operate as a force sensor by applying stress to plate 9 in a direction parallel to the axis of beam 1 as shown by arrows 22. The resulting stress in beam 1 causes a change in its flexural resonance frequency and hence a change in oscillation frequency. Measurement of the oscillation frequency by frequency counter 21 provides a measure of the force applied to plate 9. Alternatively, the force may be applied to plate 9 by bending it into an arc of a circle causing stress in beam 1 and hence a change in its resonance frequency.
The described embodiment may be adapted to be a pressure sensor by using a pressure sensitive diaphragm in place of plate 9. A capsule covering one surface of the diaphragm allows a differential pressure to be exerted across it when gas is admitted to the capsule under pressure. As the differential pressure across the diaphragm changes, the stress in beam 1 changes and hence the beam oscillation frequency changes. The oscillation frequency may be measured by the method already described, and its value provides a measure of the applied pressure.
The force sensor may also be readily adapted to be a temperature sensor. In addition to the structure described previously and illustrated in FIG. 3, a plate of metal or other suitable material is attached to the back of silicon plate 9. The additional plate, being made of a material such as aluminium, has a significantly different coefficient of thermal expansion to the silicon plate. The resulting difference in thermal expansion causes stress to be set up in plate 9, having a magnitude dependent upon the temperature. The stress in beam 1 and hence its oscillation frequency will therefore be temperature dependent, a measurement of the oscillation frequency providing an indication of temperature.
The embodiment of the invention as described, is a self-oscillating optical device in which a vibratable body is driven by a light source using the photo-thermal effect. The intensity of incoming light is modulated by the displacement of the body by means of a Fabry-Perot interferometer, to provide positive feedback between the driving force and the motion of the beam.
In an alternative embodiment of the invention, the intensity of incoming light is modulated by the displacement of the body by means of a selective masking technique which provides a positive feedback between the driving force and the motion of the beam.
Referring to FIG. 4, a thin rectangular beam 23 is made from a rigid material such as a metal, or a crystalline material such as silicon or quartz and is attached at each end to a comparatively massive mounting assembly 24 in such a way that it can freely vibrate in a flexural mode in a plane roughly perpendicular to the plane of the paper. A beam of light 25, preferably from a continuous unmodulated laser source, is focussed by lens 26 into a small spot which is incident on the outer surface of beam 23 at a point roughly midway between the mountings at each end.
The position of the focussed spot is explained in more detail with reference to FIG. 5, which shows a cross-sectional view of beam 23. denoted by 23' with the light beam 25' focussed by lens 26' into a focussed spot 27. The centre of the light spot 27 is displaced by a certain distance x from the neutral axis 28 of vibrating beam 23 so that the thermal expansion of the beam resulting from absorption of power from the light spot produces a bending moment about the neutral axis 28. An optically reflecting metal layer 29 is attached to the surface of beam 23' in such a position that it intercepts approximately half the area of the focussed spot 27 on the side closest to the neutral axis 28. The remainder of the beam surface illuminated by spot 27 is covered by a layer of an optically absorbing material 30 which absorbs the greater part of the light incident upon it.
When the light beam is initially switched on and the beam 23' is at rest, the absorption of light by material 30 causes heating of this layer which is rapidly transferred by thermal conduction to the beam material underneath. The localised thermal expansion of the beam caused by the heating produces a bending moment in beam 23' which tends to move it approximately in the direction shown by arrow 31. As a result of this movement, a smaller area of absorbing material 30 is exposed to light spot 27 and the heating becomes less. As the heating is reduced, beam 23' cools and moves back to its original position where the cycle begins again. During each cycle, beam 23' gains a small amount of vibrational energy from the heat supplied by the light beam and loses a small amount of energy as a result of various forms of vibrational damping such as internal frictional losses in the beam material and acoustic radiation to its surroundings. If the energy gain per cycle is greater than the energy loss, the vibrational amplitude increases after each cycle and builds up to a steady maximum amplitude where the oscillation becomes self-sustaining.
In an alternative embodiment, instead of using a rectangular vibratable beam as described previously, a photo-thermal oscillator may also be constructed using a vibratable wire as shown in FIG. 6. A round wire 32 shown here in cross-section, is suspended between two comparatively massive and rigid supports (not shown) in such a way that it can vibrate freely in a flexural mode. The wire is made from a metal such as aluminium which has a highly reflecting surface, or is made from a non-reflecting material such as a glass fibre with a highly reflecting coating such as aluminium, deposited upon it. A semi-cylindrical section of the wire is coated with a thin opaque absorbing layer 33, such as black matt paint, over a short length, midway between the supports. A laser beam 34 is focussed by a lens 35 into a focussed spot 36 which is incident on the wire surface at the midpoint between the supports. The focussed spot 36, which should ideally be somewhat smaller than the wire diameter, is positioned such that half the spot covers the opaque layer 33 and half the reflective surface of the wire. The device operates as a photothermal oscillator in substantially the same way as the rectangular beam device described with reference to FIGS. 1 and 3. The angle which the plane of vibration, defined by the arrows 37 and 37', makes with the direction of the light beam is some angle intermediate between 0 and 90° which causes the bending moment about the neutral axis of the wire and the thermal modulation per unit vibrational displacement of the wire to be simultaneously maximised. In practice, the angle is in the region of 45° to the light beam axis.
An approximate calculation has been done to find the minimum power needed to cause self-oscillation. For an aluminium wire 25 micrometers in diameter and 6 mm long vibrating in the fundamental flexural mode at a frequency of approximately 3 kHz with a Q-factor of 1000 (the Q-factor is used to indicate the amount of energy locked in the vibrating structure relative to the amount of energy that must be fed in to maintain the vibrations), and illuminated by a focussed spot 5 micrometers in diameter, the minimum power needed for self-oscillation is approximately 25 microwatts. This is well within the power available from continuous semiconductor lasers using a single mode or multi-mode optical fibre to conduct the light from the laser to the photo-thermal oscillator.
For both types of oscillator described above, a proportion of the input light is reflected back from the vibrating surface in a direction parallel to the incoming light and will therefore be returned along an optical fibre connection between the laser source and the oscillator. The return light is modulated at the beam vibration frequency and may therefore be used to measure this frequency. | A sensor comprises a beam, e.g. of silicon, which resonates at a frequency dependent on the force imposed on the beam. Light on a line induces resonance of the beam by means of the photothermal effect. The light reflected from the beam is amplitude modulated at the resonance frequency, and returns along the line. It is reflected by a semi-reflecting plane mirror onto a lens which focusses it onto a photodetector. The photodetector produces an output voltage modulated at the oscillation frequency, and is thus representative of the force imposed on beam 1. | 6 |
BACKGROUND OF THE INVENTION
The present invention is related to providing a clothes washing machine having means for circulating water from the bottom of a basket to the top thereof under the action of an oscillating agitator.
A conventional clothes washing machine is configured, as shown in FIG. 6, to provide a water tank 2 which is provided in the inside of a body 1 and containing a predetermined volume of water needed for a washing cycle. A hydrating spinning basket 3 is housed in the tank 2 and has a pulsator 4. A power generating member 5 is provided beneath the tank 2 for transmitting the power to the dehydrating basket 3 or the pulsator 4.
The power generating member 5 comprises a motor 5a provided beneath the water tank 2, and a power transmitting element 5b for operating the basket 3 and the pulsator 4 by the power of the motor 5a.
Further, at a predetermined area of the inner wall of the basket 3 there is formed a water guide duct 3a for guiding the water upwardly from the pulsator 4. The water guide duct 3a comprises an inlet 3b provided at the lower end and receiving the water from the pulsator during the washing and the rinsing cycle, an outlet 3c provided at upper end for discharging water, and a filter 3d detachedly provided at the front of the outlet 3c for collecting lint contained in the discharged water through outlet 3c.
The typical conventional art is described in Japanese Patent Laid Open Publication No. 80- 24066 (1980.2.20).
In the washing machine having the above structure, the pulsator 4 is oscillated by the power transmitted from the motor 5a, and thus the washing and the rinsing cycle are achieved.
As the rotating pulsator 4 acts as an impeller, part of the washing water is forcefully induced to the inlet 3b of the water guide duct 3a, and the water through the inlet 3b is discharged from the outlet 3c of the water guide duct 3a, which is circulated during the washing cycle.
While the process can be repeated during the predetermined programmed period, the washing step and the rinsing step are accomplished. The lint accompanying the water is discharged through the outlet 3c, and is collected by the filter 3d. While the washing machine has a fairly effective washing cycle, it has the following problems.
In both the washing and rinsing cycles, the oscillating pulsator 4 is causes the water to turn into a stream. Since the water tends to be directed to the inlet 3b of the water guide duct 3a which is formed as a single opening in the inner wall of the basket 3, a swirling effect of the water occurs particularly adjacent to the inlet 3b. The swirling of the water causes the clothes to become extremely twisted. Additionally, since the stream of water is concentrated adjacent to the single inlet, no effective circulation of the water can be achieved and not enough detergent can be dissolved which decreases the cleaning efficiency of the washer. Further, the undissolved detergent is drained with the drain water which results in a waste of detergent and water pollution.
Furthermore, above-described swirling generated by the rotation of the pulsator raises the clothes toward the upper central surface of the water, so the clothes are exposed above the water surface. When this occurs, the washing efficiency decreases.
In order to resolve these problems, one of the main objectives of the present invention is to provide a clothes washing machine having a plurality of passages from which most of the water pours down to the central portion of the dehydrating basket, forming a waterfall, so the clothes which rise above the water surface by the rotation of the pulsator are forced downward until fully immersed, thereby increasing the washing efficiency.
Another objective of the present invention is to provide each passage with a vortex chamber, in which the lint contained in the water is easily separated.
Still another objective of the present invention is to provide each passage with vertically spaced water outlets generating different water heads, in which the clothes in the lower water head as well as the higher water head can be immersed, and the turbulence of the water can easy be developed.
SUMMARY OF THE INVENTION
In order to accomplish these objects, the present invention relates to a clothes washing machine which comprises an upwardly open water container having water therein; a dehydrating basket disposed in the water container; a power transmitting means for transmitting the power of a motor to the dehydrating basket; an oscillatory pulsator disposed in the bottom of the dehydrating basket for being operated by the turning direction of the power transmitting means; an impeller having a plurality of vanes extending radially on the bottom surface of the pulsator; channels attached to the inner wall of the dehydrating basket for guiding the water discharged from the impeller to be run upwardly. Further, the channel has a water inlet at the lower end, a first water outlet at the upper end, and a second water outlet below to the first water outlet, the second water outlet having a lint filter.
Furthermore, at the upper end of the channel there is provided a vortex chamber which curves toward the first water outlet.
Furthermore, a third water outlet is provided below the second water outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be explained in detail with reference to the attached drawings, in which:
FIG. 1 is a vertical cross-sectional view showing a clothes washing machine provided with a plurality of channels according to the present invention;
FIG. 2 is a perspective view of a channel of FIG. 1;
FIG. 3 is a vertical cross-sectional view of an upper end of the channel of FIG. 2;
FIG. 4 is a vertical cross-sectional view taken along line IV--IV of FIG. 2;
FIG. 5 is a view similar to FIG. 2 of another embodiment of a channel; and
FIG. 6 is a vertical cross-sectional view showing a prior art clothes washing machine provided with a channel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 represents a clothes washing machine according to the present invention, which includes a body 10. The body 10 is provided with a water container 20 which retains washing-water therein and a washing tank or dehydrating basket 30 which receives clothing. The dehydrating basket 30 includes a horizontal bottom wall and a cylindrical vertical wall. A balance ring 50 extends around the upper edge of the vertical wall of the basket 30 for preventing the vibration of the basket 30 during the operation. The dehydrating basket 30 further has a pulsator 40 positioned above the bottom of the basket 30, which is connected to a power transmitting means 60 mounted beneath the water container 20.
Further, the pulsator 40 has a plurality of vanes or impeller blades 43 projecting downwardly from the bottom surface of the pulsator 40. Each vane 43 extends in a radial straight direction. The height of the vane 43 is varied to the peripheral from the center of the pulsator 40. That is, the highest wall is in the center of the pulsator 40, while the lowest wall is at the circumference of the pulsator 40. This causes the water in the bottom central portion of the water container 20 to be drawn-in, and the drawn-in water is discharged along the vane in a radial outward direction.
Furthermore, a plurality of channels 70 are formed longitudinally, or from the bottom to the upper opening of the basket 30, on the inner wall of the dehydrating basket 30. In FIG. 2, the channel 70 comprises a body 71 having a planar plate 71P extending parallel to and spaced inwardly from the vertical wall of the basket 30, and a pair of side plates 71S which abut the vertical wall of the basket so that there is formed a passage 76 which is bordered by the planar plate 71P, the side plates 71S, and the vertical wall of the basket 30, which passage 76 is utilized for conducting water.
The channel 70 further comprises horizontally inwardly facing inlet 72 which is formed at the lower end of the body 71 for receiving the water discharged from the ends of vanes 43, a first outlet 81 formed between the upper end of the body 71 and a lower portion of spring 50 for discharging the water running upwardly through the passage 76, and a second outlet 82 formed below the first outlet 81. The second outlet 82 has a filter net 83 which is used for collecting the lint from the water. Further, the first outlet 81 is formed for directing the water from the passage 76 of the body 71 inwardly toward the central portion of the basket 30. The channel 70 furthermore comprises a third outlet 73 formed at the middle of the planar plate 71P of the body 71. At the upper edge of the third outlet 73 is provided a vane 75 extending into the passage 76 for diverting part of the water running upwardly through the passage 76 into the basket 30. Also, the third outlet 73 is formed for directing water toward the peripheral portion of the swirling water in the basket 30. Alternatively, the third outlet 73 might be formed of a plurality of apertures 74 as shown in FIG. 5.
The upper end of the passage 76 70 is provided with an enlargement defining a vortex chamber 84 with the first outlet 81 and the second outlet 82 disposed at the inward surface of the vortex chamber 84 as shown in FIG. 3. The transverse cross-section of the vortex chamber 84 is wider than that of the passage 76 of the body 71 (see FIG. 3). Thus, the upwardly running water through the passage 76 of the body 71 flows into the vortex chamber 84 to be changed into a vortex flow. The vortex chamber 84 further has a smoothly curved overhead wall formed by a bottom portion of the balance ring 50. The rising water through the passage 76 of the body 71 can be smoothly discharged.
The operation of the above structural washing machine will now be explained with reference to the attached drawings.
Clothes are put into the basket 30 having a predetermined volume of water. Firstly, the pulsator 40 is oscillated by the power transmitting means 60. Part of the water over the pulsator flows down the under surface of the pulsator 40 through a plurality of openings (not shown) formed in the pulsator 40. The plurality of vanes 43 formed on the lower surface of the pulsator 40 simultaneously move with the pulsator 40. The plurality of vanes 43 are utilized as an impeller. Since each vane 43 is configurated in a straight line, the water between the under surface of the pulsator 40 and the upper surface of the bottom of the water container 20 is radially spread regardless of the direction of rotation of the pulsator 40. The water contained on each vane 43 is forcefully directed to each inlet 72 of the channels 70. The water from each inlet 72 is forced up along the passage 76 of the respective body 71 by the rotation of the impeller. Part of the rising water is discharged through the third outlet 73, and is poured forth as the peripheral portion of the swirling water in the dehydrating basket 30.
Most of the rising water flows into the vortex chamber 84. Due to the vortex effect in the chamber 84, the lint and the water are easy separated. The lint water-laden is relatively heavier, while the water lighter. Thus, the water is guided toward the first outlet 81, and the lint is directed to the second outlet 82 to be collected by the filter 83. The water passing through each first outlet 81 is discharged toward the central area of the water surface in the basket 30. Since a plurality of first outlets 81 are disposed around the upper edge of the basket 30, the falling water can powerfully force the water in the basket downwardly.
At the initial washing operation, part of the dry clothes are above the water surface, but the water falling down through a plurality of first outlets 81 can soon immerse all the clothes. Next, as the pulsator 40 is oscillated during the main washing cycle, the clothes at the bottom of the basket 30 rise toward the upper central portion of the water. The falling water from each first outlet 81 forces the rising clothes to be immersed again, pushing the clothes under the surface of the water. Additionally, the falling water pushes against the rising clothes in the basket 30.
Further, the efflux of the water from the third outlet 73 causes the water in the basket 30 to be more turbulent. The water from the third outlet 73 also forces the clothes toward the middle portion of the basket 30.
Thus, the efflux dropping radially down from the first (highest) outlet 81 obstructs the clothes attempting to rise above the surface of the water. The efflux strikes the clothes under the water surface, thereby increasing the washing efficiency. Besides, relatively lint-free water is discharged through the first outlet 81, thereby avoiding resistance as could otherwise be created by the presence of the water. More, the efflux from the third (lowest) outlet supports the turbulence of the water and at the same time strikes the clothes. Thus, this leads to an increase of the washing efficiency. | A clothes washing machine includes a water container, a spin-drying basket disposed in the container, and an oscillatory agitator disposed at the bottom of the basket. A plurality of upright water passages are formed in a vertical wall of the basket for conducting an upward flow of water generated by the agitator. Each passage includes vertically spaced first and second water outlets disposed above a water level in the basket. The second outlet is disposed below the upper outlet and has a lint filter. A third water outlet is formed in each passage and is disposed below the water level. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional patent application, Serial No. 60/175,457, filed Jan. 11, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to rotary drilling of subterranean formations and, more specifically, to a rotary drill bit exhibiting particularly beneficial lateral stabilization characteristics, as well as a method of drilling subterranean formations with such a rotary drill bit.
2. State of the Art
Equipment used in subterranean drilling operations is well known in the art and generally comprises a rotary drill bit attached to a drill string, including drill pipe and drill collars. A rotary table or other device such as a top drive is used to rotate the drill string from a drilling rig, resulting in a corresponding rotation of the drill bit at the free end of the string. Fluid-driven downhole motors are also commonly employed, generally in combination with a rotatable drill string, but in some instances as the sole source of rotation for the bit. The drill string typically has an internal bore extending from and in fluid communication between the drilling rig at the surface and the exterior of the drill bit. The string has an outer diameter smaller than the diameter of the well bore being drilled, defining an annulus between the drill string and the wall of the well bore for return of drilling fluid and entrained formation cuttings to the surface.
An exemplary rotary drill bit includes a bit body secured to a steel shank having a threaded pin connection for attaching the bit body to the drill string, and a body or crown comprising that part of the bit fitted on its exterior with cutting structures for cutting into an earth formation. Generally, if the bit is a fixed-cutter or so-called “drag” bit, the cutting structure includes a plurality of cutting elements including cutting surfaces formed of a superabrasive material such as polycrystalline diamond and oriented on the bit face generally in the direction of bit rotation. A drag bit body is generally formed of machined steel or a matrix casting of hard particulate material such as tungsten carbide in a (usually) copper-based alloy binder.
In the case of steel body bits, the bit body is usually machined, typically using a computer-controlled, five-axis machine tool, from round stock to the desired shape, including internal watercourses and passages for delivery of drilling fluid to the bit face, as well as cutting element pockets or sockets and ridges, lands, nozzle displacements, junk slots and other external topographic features. Hardfacing is applied to the bit face and to other critical areas of the bit exterior, and cutting elements are secured to the bit face, generally by inserting the proximal ends of studs on which the cutting elements are mounted into apertures (sockets) bored into the bit face or, if cylindrical cutting elements are employed, by inserting the substrates into pockets bored into the bit face. The end of the bit body opposite the bit face is then threaded, made up and welded to the bit shank.
The body of a matrix-type drag bit is cast in a mold interiorly configured to define many of the topographic features on the bit exterior, with additional preforms placed in the mold defining the remainder of such features as well as internal features such as watercourses and passages. Tungsten carbide powder and sometimes other metals to enhance toughness and impact resistance are placed in the mold under a liquefiable binder in pellet form. The mold assembly, including a steel bit blank having one end inserted into the tungsten carbide powder, is placed in a furnace to liquify the binder and form the body matrix with the steel bit blank integrally secured to the body. The blank is subsequently affixed to the bit shank by welding. Superabrasive cutting elements, also termed “cutters” herein, may be secured to the bit face during the furnacing operation if the elements are of the so-called “thermally stable” type, or may be brazed by their supporting (usually cemented WC) substrates to the bit face, or to WC preforms furnaced into the bit face during infiltration. Such superabrasive cutting elements include polycrystalline diamond compacts (PDCs), thermally stable polycrystalline diamond compacts (generally termed “TSPs” for thermally stable products), natural diamonds and, to a lesser extent, cubic boron nitride compacts.
Rotary drill bits, and more specifically drag bits, may be designed as so-called “anti-whirl” bits. Such bits use an intentionally unbalanced and oriented lateral or radial force vector, usually generated by the bit's cutters, to cause one side of the bit configured as an enlarged, cutter-devoid bearing area comprising one or more gage pads to ride continuously against the side wall of the well bore to prevent the inception of bit “whirl”, a well-recognized phenomenon wherein the bit precesses around the well bore and against the side wall in a direction counter to the direction in which the bit is being rotated. Whirl can result at the least in an over-gage and out-of-round well bore and, at its worst, in damage to the cutters and bit itself. Anti-whirl bits have been designed, built and run commercially, with some success. However, the necessity to calculate, and usually redirect, the lateral imbalance forces generated by engagement of a formation by a bit under rotation and weight on bit (WOB) so that the resultant lateral force vector intersects the bearing area results in additional expense in the first instance of completing a given bit design. Further, if the size, shape, type, orientation or location of any cutting element is desired or required to be changed, the magnitude and direction of the resultant lateral force vector must be recalculated, and possibly further design modifications effected to the bit to ensure proper direction and magnitude of the resultant lateral force vector.
Another disadvantage of anti-whirl bits is related to the absence of cutting elements on the shoulder as well as the gage in the bearing area, often in conjunction with longitudinally extending the gage pad or pads. While bits of such designs exhibit a high side force directed to the relatively low-friction gage pad or pads in the bearing area, resulting in reduced vibration and a smooth-running bit, the absence of the gage and shoulder cutting elements in the bearing area significantly reduces the life of the bit through premature wear.
Thus, it would be beneficial to the drill bit design to achieve a smooth-running, low-vibration drill bit which does not require the intricacies of anti-whirl bit design and re-design and which, at the same time, provides a useful life on the order of that obtainable by a conventional, nonanti-whirl drill bit.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a fixed cutter, or rotary drag, bit exhibiting enhanced lateral stability and reduced vibrational tendencies comparable to an anti-whirl bit, while at the same time providing a greater useful life in terms of resistance to wear.
The rotary drag bit of the present invention includes a bit body having a face over which may extend a plurality of generally radially extending blades, each bearing a plurality of superabrasive cutting elements. The bit body also includes a plurality of gage pads, which may comprise longitudinal extensions of the blades, or be discontinuous therewith. At least one gage pad of the plurality exhibits a longitudinal elongation toward, or even longitudinally below, the face of the bit which moves the shoulder region comprising a transition between the gage and the face profiles downwardly, as the bit is normally oriented for drilling. At least one cutting element is placed in the area of gage pad elongation, the at least one cutting element exhibiting an exposure less than the exposure of cutting elements on the bit face. Desirably, at least another reduced-exposure cutting element is placed in the shoulder region forming the transition between the gage pad and its associated blade.
The rotary drag bit of the present invention may be configured as a conventional or anti-whirl bit in terms of the degree and magnitude of the resultant lateral force vector causing lateral imbalance of the bit. However, a bit in accordance with the present invention may also employ all of the gage pads in the above-described longitudinally elongated configuration, each of the gage pads bearing at least one cutting element of lesser exposure than the bit face cutting elements and at least another cutting element of lesser exposure on the shoulder region. By using such an approach, the direction of lateral bit imbalance is of little or no concern to the bit designer, who need only determine that the magnitude of such imbalance is within certain broad parameters. Further, the magnitude of the lateral bit imbalance may be increased beyond that deemed wise conventionally, so as to more firmly stabilize the rotating bit against the side wall of the borehole, the extended gage region and reduced-exposure cutting elements providing sufficient durability and wear resistance to accommodate the increased lateral loading.
Thus, a bit in accordance with the present invention may be of conventional design and exhibit a wide variation in lateral imbalance, from a very low magnitude to a magnitude in excess of what have hitherto been deemed to be acceptable levels, or may be of an anti-whirl design. In addition, the term “rotary drill bit” or “bit” as employed herein encompasses core bits, bi-center bits, eccentric bits, reaming-while-drilling (RWD) tools, as well as other rotary drilling structures which may benefit from the improvements and advantages afforded by the present invention.
The present invention also encompasses a method of drilling subterranean formations.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 of the drawings comprises a view of superimposed partial bit blade profiles in the shoulder region, one of conventional configuration and the other configured according to the invention, the latter showing cutter placements;
FIGS. 2A and 2B comprise enlarged perspective views of a conventional gage pad and shoulder design for a low-friction gage pad as employed in the bearing area of an anti-whirl drill bit;
FIGS. 3A, 3 B and 3 C comprise enlarged perspective views of elongated gage pads and longitudinally displaced shoulder regions according to the present invention;
FIGS. 4A and 4B comprise side profiles of bits bearing the same cutting structure, wherein FIG. 4A depicts a bit exhibiting a conventional profile and FIG. 4B depicts a bit exhibiting a profile according to the present invention; and
FIGS. 5A, 5 B and 5 C respectively comprise a face view, a side profile and a side sectional elevation of an exemplary drill bit according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 of the drawings, two superimposed partial bit blade profiles 10 (solid line) and 100 (broken line) are shown. Profile 10 exemplifies a blade 12 extending radially outwardly and longitudinally upwardly at a relaxed, relatively small angle α to the bit axis L to and through a shoulder region 14 to a gage pad 16 , such a configuration being currently employed in anti-whirl bit designs. In such designs, shoulder region 14 and gage pad 16 in the bearing area are each completely devoid of cutting elements. Profile 100 exemplifies a blade 112 extending radially outwardly and longitudinally upwardly at a relatively larger angle β to the bit axis L to and through a shoulder region 114 to a gage pad 116 including extended gage region 118 longitudinally elongated in a direction toward, or even in advance of, the bit face according to the invention. As shown on the profiles 10 and 100 , a plurality of cutting elements 20 and a plurality of flat-edged gage cutting elements 22 which are, in fact, distributed over the bit face and at different circumferential locations around the gage have been rotationally superimposed into a single plane for clarity It can be readily appreciated that at least one, and preferably several, of the gage cutting elements 22 which would be missing from profile 10 (and thus carried on other gage pads circumferentially outside the bearing area of the anti-whirl bit) are carried on extended gage region 118 . As shown, cutting elements 20 on shoulder region 114 and gage cutting elements 22 on extended gage region 118 of profile 100 are of lesser exposure, or height, above (e.g., outwardly from) the profile in comparison to cutting elements 20 carried on blade 112 over the bit face. Thus, while not cutting aggressively, as do cutting elements 20 on the blade 112 over the bit face, the shoulder region cutting elements 20 and extended gage region cutting elements 22 provide enhanced durability and wear resistance to the bit body in those areas. It should also be noted that gage cutting elements 22 and shoulder region cutting elements 20 exhibit, on those blades 12 carrying same on conventional profile 10 , much greater exposure than on extended gage region 118 and shoulder region 114 on profile 100 . Thus, these cutting elements take a greater depth of cut and perform much more aggressively on profile 10 than on profile 100 , consequently being more likely to excite vibration.
While it has been asserted by those skilled in the art that a cutter-devoid, low-friction gage pad in the context of an anti-whirl bit is the only means by which bit vibration, and specifically whirl, may be attenuated, the inventor herein has determined that such is not the case. Rather, by longitudinally extending all of the gage pads toward the bit face and placing reduced-exposure cutting elements on the extended gage regions, an anti-whirl bit design is rendered unnecessary, as any lateral imbalance force exhibited by the bit under rotation and WOB is sufficiently accommodated by the present invention anywhere about the circumference of the bit. Furthermore, if it is desired to employ a lateral force vector, such vector does not have to be aimed at any particular circumferential location or region, but again is sufficiently accommodated by the present invention regardless of direction. In addition, the present invention provides the opportunity to even increase the lateral force pushing a bit against the borehole wall to stabilize the bit, while the reduced-exposure cutting elements in the shoulder region and extended gage region provide durability without inciting whirl or other vibratory tendencies.
FIGS. 2A and 2B of the drawings depict, in an enlarged, inverted, perspective view, a blade 12 of a bit having a conventional anti-whirl profile 10 , cutting elements 20 being carried on blade 12 while shoulder region 14 and gage pad 16 therebelow are completely devoid of cutting elements. As may readily be appreciated from FIGS. 2A and 2B, the shoulder region 14 and gage pad 16 are substantially unprotected from wear and damage resulting from the bit being pushed against the side wall of the borehole under a resultant lateral force vector used to stabilize the bit.
FIGS. 3A, 3 B and 3 C comprise enlarged, inverted perspective views of blades 112 (FIGS. 3A and 3B depicting one blade 112 and FIG. 3C depicting another blade 112 ) with associated shoulder regions 114 and extended gage regions 118 of gage pads 116 . Reduced exposure gage cutting elements 22 are shown on extended gage regions 118 , and reduced exposure cutting elements 20 on shoulder regions 114 . By way of comparison with cutting elements 20 carried on blades 112 , if such cutting elements 20 are exposed (as is conventional) to a height above the profile of about one-half of the diameter of the cutting faces 21 thereof, the exposure of cutting elements 20 on shoulder regions 114 may be desirably less than the exposure of cutting elements 20 on blades 112 , or perceptibly less than one-half of the cutting faces 21 . The exposure of gage cutting elements 22 is preferably less than the exposure of cutting elements 20 on shoulder regions 114 , and the outer extents of cutting elements 22 may be flush with matrix material of the bit body, the gage cutting elements 22 being exposed as the bit is run due to matrix wear. However, it is currently preferred that gage cutting elements 22 be exposed about 0.025 inch (about 0.6 mm). Thus it will be understood, and is especially well illustrated with reference to FIG. 1, that the exposure of gage cutting elements 22 may be very slight, as no significant cutting action is required and, indeed, the opposite is true. In other words, such cutting elements 22 in combination with cutting elements 20 in shoulder regions 114 are intended only to substantially preserve the integrity of the shoulder regions 114 and gage pads 116 , the extended gage region 118 of the latter preventing gage cutting elements 22 from biting into the wall laterally, but not affecting the axial aggressiveness of the bit as the cutting elements 20 cut the borehole.
FIGS. 4A and 4B further illustrate the physical differences between a bit having a conventional profile (FIG. 4A ) and a profile according to the present invention (FIG. 4 B). Reference numerals previously employed herein are used in FIGS. 4A and 4B to identify the same features.
FIGS. 5A, 5 B and 5 C depict an exemplary 8½ inch, six-bladed rotary drag bit in accordance with the present invention. Reference numerals previously employed herein are used in FIGS. 5A, 5 B and 5 C to identify the same features. In addition, FIG. 5A depicts the fluid courses 122 on bit face 120 , and nozzles 124 proximate the radially inner extents of fluid courses 122 , each nozzle substantially providing drilling fluid to two fluid courses 122 . It will be noted that the bit includes three relatively longer primary blades 112 which each carry a noticeably larger number of cutting elements 20 than the three relatively shorter secondary blades interspersed therebetween. FIG. 5B depicts the blade profile of the bit according to the present invention, and its relationship to bit face 120 whereon fluid courses 122 are located, leading to junk slots 126 defined between gage pads 116 . Radial locations and orientations of passages 130 leading to nozzle locations 132 (nozzles 124 not shown) adjacent fluid courses 122 from plenum 134 inside bit body 136 are also shown. FIG. 5C is a side sectional elevation of the exemplary bit, further including shank 138 which is threaded at 140 to effect a connection to a drill string or a drive shaft of a downhole motor, as known in the art.
It should be noted that superabrasive cutting elements, and specifically PDCs, are the currently preferred structures for cutting elements 20 and 22 . The manner in which the exposure of gage cutting elements 22 and cutting elements 20 in the shoulder region of bits according to the invention may be reduced may vary. For example, smaller diameter cutting elements may be employed than those employed on the blades over the bit face, the cutting elements may be physically more closely inset toward the profile, the rake angle may be increased more negatively, the cutting edges may be trimmed as by electrodischarge machining (EDM) to reduce exposure, or a combination of such approaches may be employed. However, the invention is not limited to implementation with PDC cutting elements, and other superabrasive cutting structures, including without limitation TSPs, natural diamonds, diamond films and cubic boron nitride, may be employed.
The present invention, by employing enhanced gage pad bearing surfaces in combination with reduced-exposure cutting elements on the extended gage regions, as well as on the adjacent shoulder regions, greatly enhances lateral stability and attenuates vibrational tendencies associated with lateral bit movement without sacrificing longevity and durability as in prior art anti-whirl bits with their cutter-devoid, low-friction gage pads and adjacent shoulder regions in the bearing area. Moreover, bits configured according to the present invention may be designed in a more straightforward manner than such prior art anti-whirl bits with their requirements for alteration of cutting element numbers, positions and orientations to achieve a directed resultant lateral force vector within a certain magnitude range. Further, since bits according to the present invention will operate effectively regardless of the direction and magnitude of any resultant lateral force vector, cutting elements may be placed on such bits to optimize cutting action and to increase hydraulic efficiency, facilitating increases in rate of penetration (ROP) absent many constraints imposed by prior art anti-whirl bit designs. Thus, the present invention includes a method of drilling demonstrating enhanced lateral stability while, at the same time, facilitating increased flexibility in bit design to achieve superior performance.
While the present invention has been described in the context of certain preferred embodiments, those of ordinary skill in the art will understand and appreciate that the invention is not so limited. Specifically, additions and modifications to, and deletions from, the embodiments described and illustrated herein may be made without departing from the scope of the invention as hereinafter claimed. | A fixed cutter, or rotary drag, bit exhibiting enhanced lateral stability for drilling subterranean formations and a method of drilling. The bit includes one or more gage pads longitudinally extended in the direction of the leading end of the bit and preferably forwardly of the bit face, the gage pads and preferably the adjacent shoulder regions each bearing at least one cutting element thereon exhibiting a reduced exposure in comparison to cutting elements carried on the face of the bit. The increased gage pad area may be employed as a bearing area to accommodate a large resultant lateral force vector and the extended, reduced-exposure cutting element-carrying gage pads and adjacent shoulder regions may be deployed about the entire circumference of the bit so the direction of any resultant force vector is substantially immaterial to the bit design. | 4 |
FIELD OF INVENTION
[0001] This invention relates method and system for training a hearing aid using a self-organising map (SOM) neural network for performing automatic program selection.
BACKGROUND OF INVENTION
[0002] U.S. Pat. No. 6,044,163 discloses a hearing aid comprising an input transducer, an amplifier and transmission circuit, an output transducer and a calculating unit working according to the principle of a neural structure. The calculating unit performs a classification in order to modify the transmission characteristics in dependence on the auditory situation. The training is distinguished between, firstly, a non-supervised training, which occurs according to a predetermined matrix only upon evaluation of an event signal generated by the calculating unit, and, secondly, a supervised training where a matching module evaluates a desired target reply in addition to the event signal. The US patent provides an approach using a neural structure, which may be trained during the operating mode. However, since the disclosed neural structure comprises a multi-layer neural network an intensive calculation in order to update the neuron weights is required.
[0003] International patent application WO 2004/056154 discloses a hearing device having an input transducer, an output transducer, and signal processing means for influencing a signal in the hearing device in accordance with a processing parameter set (PPS). A PPS memory accessible by the signal processor means stores a number of different PPS's for use by the signal processing means. The system further has means for monitoring the acoustic environment in a learning mode, where the user selects a PPS. Later in an automatic mode the hearing device selects a PPS based on a comparison between the current acoustic environment and the monitored environment in the learning phase. This hearing device discloses a classification system where the most representative characterizing acoustic values are calculated for each PPS. However, the performance may decrease, if a PPS has to be used for different characterizing acoustic values. That is, according to this hearing device a characterizing acoustic value matches a similar PPS.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to provide an improved method and system for training a hearing aid using neural network to perform an automatic program selection based on a plurality of characterizing acoustic values.
[0005] In particular, the object of the present invention is to enable plurality of sets of characterizing acoustic values result in selection of one program.
[0006] A particular advantage of the present invention is the provision of a system which does not require large computing capabilities.
[0007] A particular feature of the present invention is the provision of enabling the end-user to train the hearing aid during the operation of the hearing aid in real-life situations.
[0008] The above objects, advantage and feature together with numerous other objects, advantages and features, which will become evident from below detailed description, are obtained according to a first aspect of the present invention by a system for selecting a signal processing program to be executed by a signal processor in a hearing aid and comprising a single layer of neurons each having one or more neighbours and being arranged in a memory device, and each neuron comprising a neuron vector referring to a specific acoustic situation and a neuron label referring to signal processing program associated with said specific acoustic situation, and comprising a sensor adapted to detect an external acoustic situation and to define a sensor vector associated with said external acoustic situation, wherein said processor is adapted to calculate a vector difference between said sensor vector and each of said neuron vectors, to identify that neuron providing the smallest vector difference, and to select a signal processing program referred to by a neuron label of that neuron.
[0009] The system according to the first aspect of the present invention provides an automatic selection of signal processing program based on the trained grid of neurons. The selection ensures that the most probable acoustic situation is identified and appropriately dealt with.
[0010] The system according to the first aspect of the present invention may be operable in one or more training phases and an operating phase. The operating phase is to be construed as a classification phase wherein the hearing aid is in operation, and the training phases are to be construed as phases during which the value of the neuron labels are selected and adapted and during which associated acoustic situations stored.
[0011] The sensor according to the first aspect of the present invention may comprise a first detector for detecting signal level in one or more frequency bands and providing a first parameter for the sensor vector, a second detector for detecting modulation index in one or more frequency bands and providing a second parameter for the sensor vector, a third detector for detecting speech and providing a third parameter for the sensor vector, and fourth detector for detecting a speech to noise ratio and providing a fourth parameter for the sensor vector. A wide variety of detectors may be implemented in the system, in order to accomplish any desired response of the signal processor. The detectors, however, should allow for distinguishing between different external acoustic situations.
[0012] The single layer of neurons according to the first aspect of the present invention may further be arranged in a ring-shaped, quadratic, rectangular, hexagonal configuration or any combination thereof. That is, each neuron may be arranged with 2, 4, 6 or 8 neighbouring neurons. The configuration of the single layer of neurons is particular important during the training phases. Hence the single layer of neurons may generally be connected in any networking shape such as ring or torus.
[0013] The single layer of neurons according to the first aspect of the present invention may be arranged as a self-organizing map (SOM). When the single layer of neurons is configured in a quadratic, rectangular, or hexagonal configuration, the single layer of neurons may comprise a grid length larger than 2 neurons and a grid width larger than 2 neurons. The grid of neurons may thus be arranged as a 5 neurons by 5 neurons grid. The grid size is chosen so as to provide a required number of specific acoustic situations. The grid size is, however, restraint by the size of the memory device.
[0014] The vector difference according to the first aspect of the present invention may be calculated as Euclidian distance:
dist = ∑ i = 1 d M ( i ) a ( i ) - b ( i ) 2 , Equation 1
where ‘i’ comprises an index number, ‘M’ comprises a weighting variable enabling weighting of each parameter in the sensor vector, ‘d’ comprises dimension of neurons, ‘a’ comprises a neuron vector, and ‘b’ comprises a sensor vector.
[0015] The memory device according to the first aspect of the present invention may further be adapted to store training data, which comprises an end-user's signal processing program preferences. The end-user's preferences comprising operation parameters and signal processing program choices may be stored during the training phases of the system.
[0016] During the training phases of the system the end-user may adjust operation parameters of the system or change between signal processing programs and thereby provide generation of a control setting to the training data for a particular acoustic situation. For example, by adjusting operating parameters of the signal processing program or by selecting a different signal processing program for a particular external acoustic situation the end-user may cause the system to generate a control setting to be input to the training data. The control setting may comprise the actual adjustments performed by the end-user or may comprise a differentiation of the actual adjustments performed by the end-user. Hence a particular advantageous system is obtained since if the end-user, for example, increases the gain by 6 dB the gain of the hearing aid is increased by 6 dB, but the control setting input to the training data may be a gain increase of 2 dB.
[0017] The signal processor according to the first aspect of the present invention may further be adapted to generate the neuron label based on the training data. The end-user's responses to the system's selection of a signal processing program are used in a training phase to determine a value of the neuron label for a specific acoustic situation. The neuron label refers to an associated signal processing program. Hence the system learns during the training phase which signal processing programs the end-user prefers to be used during a specific acoustic situation. This is a great advantage since the hearing aid thereby achieves a simple customization.
[0018] The system according to the first aspect of the present invention may further comprise a first counter adapted to record a number of counts for use of each signal processing program in a specific acoustic situation. During the training phase the end-user's selection of signal processing programs in a specific acoustic situation is counted and the signal processor utilises this information to provide a value for the neuron label. The signal processing program selection with most ‘hits’ during a specific acoustic situation determines the value of the neuron label.
[0019] The signal processor according to the first aspect of the present invention may further be adapted to identify a signal processing program having the highest number of counts in the first counter and a signal processing program having the second to highest number of counts in the first counter, and to compare a first difference between the highest number of counts in the first counter and the second to highest number of counts in the first counter with a first threshold. In case the first difference is lower than the first threshold the signal processor may set the value of the neuron label to zero or null. Thus during operation of the system in situations where the acoustic situation results in a selection of a neuron having a neuron label with a zero value, the signal processor may select a signal processing program used prior to change of acoustic situation.
[0020] When the first difference is little the confidence level is low and therefore the system advantageously preserves the running signal processing program rather than changing to a new signal processing program having a low confidence level.
[0021] Alternatively, the signal processor may disable each neuron having neuron label with a zero value. Hence the low confidence level for selecting a signal processing program is eliminated.
[0022] The system according to the first aspect of the present invention may further comprise a second counter adapted to record a number of counts for overall use of each signal processing program, and wherein the signal processor may be adapted to execute that signal processing program with the highest number of counts in said second counter. Hence the selected signal processing program is not necessarily executed until it has been counted the highest number of times. This is, in effect, a means for advantageously delaying program changes thereby prevented abrupt program changes.
[0023] Thus the signal processor may be adapted to compare a second difference between highest number of counts in the second counter and number of counts for a presently running signal processing program in the second counter with a second threshold, and in case the second difference is lower than the second threshold the presently running signal processing program is executed. Hence fluctuation in program selection is smoothed.
[0024] The above objects, advantages and features together with numerous other objects, advantages and features, which will become evident from below detailed description, are obtained according to a second aspect of the present invention by a method for selecting a signal processing program to be executed by a signal processor in a hearing aid comprising a single layer of neurons each having one or more neighbours and being arranged in a memory device, and each neuron comprising a neuron vector referring to a specific acoustic situation and a neuron label referring to signal processing program associated with the specific acoustic situation, and said method comprising detecting an external acoustic situation and to define a sensor vector associated with said external acoustic situation by means of a sensor, calculating a vector difference between said sensor vector and each of said neuron vectors by means of a signal processor, identifying that neuron providing the smallest vector difference by means of said signal processor, and selecting a signal processing program referred to by a neuron label of that neuron by means of said signal processor.
[0025] The method according to the second aspect of the present invention provides excellent means for a hearing aid end-user to perceive a optimum sound in a wide variety of acoustic situations.
[0026] The method according to the second aspect of the present invention may further comprise generating the neuron label based on training data. The neuron label as described above with reference to the system according to the first aspect of the present invention provides a pointer means for a specific signal processing program.
[0027] The method according to the second aspect of the present invention may further comprise recording a number of counts for use of each signal processing program in a specific acoustic situation by means of a first counter. The first counter advantageously keeps track of the number of times a particular signal processing program has been selected for a particular acoustic situation.
[0028] The method according to the second aspect of the present invention may further comprise identifying a signal processing program having the highest number of counts and a signal processing program having the second to highest number of counts in the counter, and comparing a first difference between the highest number of counts and the second to highest number of counts with a first threshold by means of the signal processor. The method may comprise setting the value of the neuron label to zero or null in case the first difference is lower than the first threshold by means of the signal processor. Alternatively, the method may comprise disabling each neuron having neuron label with a zero value by means of the signal processor.
[0029] The method according to the second aspect of the present invention may further comprise recording a number of counts for overall use of each signal processing program by means of a second counter, and executing that signal processing program with the highest number of counts by means of the signal processor.
[0030] The method according to the second aspect may further comprise comparing a second difference between highest number of counts for overall use and number of counts for a presently running signal processing program with a second threshold, and in case the second difference is lower than the second threshold executing the presently running signal processing program by means of the signal processor. The second counter advantageously keeps track of the selection of all signal processing programs in order to ensure that no abrupt program changes are achieved.
[0031] The method according to the second aspect of the present invention may incorporate any features of the system according to the first aspect of the present invention.
[0032] The above objects, advantage and feature together with numerous other objects, advantages and features, which will become evident from below detailed description, are obtained according to a third aspect of the present invention by a computer program to be run by on the system according to the first aspect of the present invention and comprising operations as defined in the method according to the second aspect of the present invention.
[0033] The above objects, advantage and feature together with numerous other objects, advantages and features, which will become evident from below detailed description, are obtained according to a fourth aspect of the present invention by a hearing aid comprising a system according to the first aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawing, wherein:
[0035] FIG. 1 , shows a neural networking system according to a first embodiment of the present invention;
[0036] FIG. 2 , shows a schematically view of a two-dimensional grid of neurons in the system according to the first embodiment of the present invention;
[0037] FIG. 3 , shows a flow chart of a rough training phase for the system according to the first embodiment of the present invention;
[0038] FIG. 4 , shows a flow chart of a fine tuning phase for the system according to the first embodiment of the present invention;;
[0039] FIG. 5 , shows a flow chart of a labelling phase for the system according to the first embodiment of the present invention; and
[0040] FIG. 6 , shows a flow chart for the system according to the first embodiment in an operation phase.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0041] In the following description of the various embodiments, reference is made to the accompanying figures, which show by way of illustration how the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention.
[0042] FIG. 1 shows a neural networking system according to a first embodiment of the present invention and designated in entirety by reference numeral 100 . The system 100 comprises a map controller 102 receiving information from a one or more environment sensors, which information is indicated by arrow 104 . The information 104 from the environment sensors defines a vector to which the system 100 must find a most probable corresponding acoustic situation. The map controller 102 compares the vector of the information 104 with sets of acoustic situations stored in map data memory 106 through communication channels 108 .
[0043] The system 100 is operated in one or more training phases and an operating phase, which generally is referred to as the classification phase. The operation of the system 100 in its training phases is described below with reference to FIGS. 3 to 5 , and firstly the system 100 is described in its operating/classification phase.
[0044] The environment sensors may according to the first embodiment of the present invention detect environmental signal properties, which should allow for distinguishing different acoustic situations. The environment sensors may for example comprise detectors for detecting environmental signal level in one or more frequency bands, a detector for detecting modulation index in one or more frequency bands, a speech detector, and a speech to noise ratio detector. That is, the acoustic situation is defined by the detected environmental signal properties having acoustic parameters detected by the environmental sensors.
[0045] The map data memory 106 comprises a two-dimensional grid of neurons 200 as shown in FIG. 2 , in which grid the neurons 202 are typically nested like hexagons. That is, nested with six neighbouring neurons. However, as is obvious to the person skilled in the art the neurons may be nested in any appropriate way. The grid 200 is a self-organising map (SOM) with a preferred size of five by five neurons. Each neuron 202 is a vector comprising ‘n’ values, where ‘n’ is the number of acoustic parameters defining the acoustic situation.
[0046] During the operating phase of the system 100 , shown in FIG. 1 , the map controller 102 computes the difference between the vector defined by the environmental sensors and the vector defined in each neuron i.e. the neuron-vector. The difference is typically calculated by equation 1, as Euclidian distance, where ‘M’ is a weighting variable enabling weighting of the individual environmental parameters so as to weight the parameters according to their relevance to environmental classification. The term “environmental classification” is in this context to by construed as the determination of the most probable acoustic situation.
[0047] When the most probable acoustic situation has been determined by the map controller 102 by selecting that neuron 202 having a neuron-vector showing the smallest difference with the vector defined by the environmental sensors, the map controller 102 communicates the coordinates of said neuron 202 the to a training data controller 110 through channel 112 . Based on the coordinates of said neuron 202 communicated to the training data controller 110 , the training data controller 110 decides which acoustic program is most likely to mirror the preferences of the end-user.
[0048] The decision of the training data controller 110 is based on training data stored in a training data memory 114 , which training data comprises end-user preferences stored during a training phase of the system 100 . The training data controller 110 communicates with the training data memory 114 through channels 116 .
[0049] The training data memory 114 comprises cyclic buffers storing the program preferences. Each neuron 202 of the grid 200 in the map data 106 corresponds to a cyclic buffer in the training data memory 114 having ‘p’ entries, where ‘p’ is the number of acoustic programs. The term ‘cyclic buffer’ is in this context to be construed as a buffer comprising a number of single cyclic buffers, where a single cyclic buffer is a way to log the number of hits a specific acoustic program receives.
[0050] When an acoustic program is selected by the training data controller 110 the associated single cyclic buffer is set to “1”, while the other single cyclic buffers are set to “0”. As will be obvious to a person skilled in the art the associated single cyclic buffer may alternatively be set to “0”, while the other single cyclic buffers are set to “1”, however, this will cause some dependent changes to be made when evaluating the count-values. A plurality of counters in the training data controller 110 continuously counts the value of each single cyclic buffer between each acoustic program selection. Hence the acoustic program corresponding to the counter with the highest value is selected as the best matching acoustic program.
[0051] The winning acoustic program provides a new label value to that neuron 202 comprising the neuron-vector closest to the vector describing the acoustic situation.
[0052] When the difference between the highest counter value and the other counter values is low, the information of the most probable program is less confident. Therefore a condition may be applied to the selection of the winning acoustic program. If the difference between the highest counter value and the second highest value is below a given margin, the associated label is set to zero. During the classification process, when the label of the best matching neuron is zero, the label of the previous best matching neuron is selected and communicated to the post-processing unit.
[0053] In an alternative embodiment the neurons labelled with zeroes are disabled. The best-matching neuron is then searched among the enabled neurons.
[0054] The training data controller 110 communicates which acoustic program is most likely to mirror the preferences of the end-user to a post-processing unit 118 through channel 120 . The post-processing unit 118 reduces environmental classification errors by smoothing fluctuations in acoustic program selection. Similar to the training data memory 114 the post-processing unit 118 comprises a cyclic buffer having a number of entries corresponding to the number of acoustic programs. When a selected acoustic program is communicated from the training data controller 110 to the post-processing unit 118 , the entry corresponding to the selected acoustic program is set to ‘1’ while the other entries are set to ‘0’. As before a counter tracks the number of ‘1’s of each entry. The acoustic program corresponding to the counter with the highest value is the selected acoustic program, which is communicated, for example by means of a pointer i.e. memory address, to an execution processor illustrated by arrow 122 . If the acoustic program, which has the highest counter value, changes, it must overstep the counter value corresponding to the presently or currently active acoustic program by a predefined margin in order to become a new best matching acoustic program. That is, a hysteresis function is applied to the counter values.
[0055] The map data in the map data memory 106 comprises N=9, 16 or preferably 25 vectors of dimension ‘n’, where ‘N’ is the number of neurons and ‘n’ is number of acoustic parameters defining the acoustic situation. Each vector may have a 2-bit resolution or higher, which is given by environmental sensors. In the first embodiment of the present invention the rough training phase is performed off-line on for example a personal computer. Therefore the map topology does not need to be stored in the hearing aid.
[0056] The training data in the training data memory 114 comprises ‘N’ cyclic buffers with ‘p’ entries, where ‘p’ is the number of acoustic programs. The cyclic buffers may have a size between 64 and 128 and the associated counters may be implemented as a counter of respectively 6 or 7 bits.
[0057] The post-processing unit 118 comprises a cyclic buffer with ‘p’ entries having a length of 8, 16, 32, or 64 bits.
[0058] The system 100 is described with reference to a classification phase, however, before the system 100 is ready for performing classification, the system 100 must be trained.
[0059] The training phase comprises adapting data in the map data memory 106 and in the training data memory 114 . The adaptation is performed in three training processes: a rough training phase, shown in FIG. 3 ; a fine tuning phase, shown in FIG. 4 ; and a labelling phase, shown in FIG. 5 .
[0060] The rough training phase designated in entirety by reference numeral 300 comprises unsupervised training, i.e. the training is performed without training data concerning acoustic program affiliation of the environmental acoustic parameters detected by the environmental sensors.
[0061] The object of the rough training phase 300 is to adapt neuron-values in the grid 200 so as to map the distribution of environmental acoustic parameter values. During a first step 302 , the neuron-vectors 202 are initialised with random values. During a second step 304 environmental acoustic parameters input to the system 100 are used to define an environmental vector.
[0062] Subsequently, during a third step 306 the environmental vector is compared to all neuron-vectors 202 , and during a fourth step 308 the best matching neuron-vector, exemplified in FIG. 2 by reference numeral 204 , is modified so that the difference between the environmental vector and the neuron-vector 204 is decreased. Further in the step 308 the neighbouring neurons 206 within a predetermined radius are also updated in accordance with a weighting function relative to the best matching neuron.
[0063] The neurons 204 and 206 are changed in accordance with equation 2.
m i ( t+ 1)= m i ( t )+α( t )* N c ( t )*[ m c ( t )− m i ( t )], Equation 2
where m i and m c ε ″. The index ‘c’ indicates the best matching neuron 204 . The function α defines the learning rate, which is decrease over time, and α is given by equation 3.
α ( t ) = α 0 * A A + t , Equation 3
where A is a constant.
[0064] The neuron 204 represents the best matching neuron and the neurons designated by reference numeral 206 represent those neurons, which are affected by an update in accordance with equation 2, the definition for N c (t) satisfying N c (t)=0 for radius (t) larger than one. A more complex definition of N c (t), which can be used for off-line simulations, is given by equation 4:
N c ( t ) = ⅇ - 0.5 * ( r radius ( t ) ) 2 , Equation 4
where radius(t) decreases linearly from the initial radius down to one. The total weight (α*Nc) can be then scaled with α 0 and A of equation 3. The steepness of the radius function is set so that the decreasing time corresponds to the assumed training time.
[0065] During a fifth step 310 the function N c (t) defining the neighbourhood or the radius and decreasing over time is updated. At this step the new N c and α are computed for the next loop.
[0066] During a sixth step 312 the function α defining the learning rate and decreasing over time is updated. In an alternative embodiment of the present invention the fifth and sixth steps 310 and 312 are removed and a third prime and third double prime steps are inserted before the fourth step 308 . The third prime step computes a new neighbour radius and the third double prime step computes a new learning factor.
[0067] Finally, in a seventh step 314 according to the first embodiment of the present invention the rough training period has concluded a first iteration. Further iterations may be initiated or the rough training phase 300 may be terminated.
[0068] FIG. 4 shows the fine tuning phase designated in entirety by reference numeral 400 . The fine tuning phase 400 is contrary to the rough training phase 300 a supervised process. The object of the fine tuning phase 400 is to group any of the neurons 202 together according to probable acoustic program.
[0069] During a first step 402 the neurons 202 are extended and the extensions are initialised with random numbers. The term “extension” is in this context to be construed as adding further parameter to each of the neuron. The further parameter refers to an acoustic program.
[0070] During a second step 404 the radius and the learning rate is modified. That is, the radius is decreased and the learning rate is maintained. However, principally the neighbour weight and the learning factor may get new values, which can differ from the initial rough training values.
[0071] During a third step 406 , in addition to the environmental sensors, the environmental vector is extended with a program extension and input to the map controller 102 . Subsequently, the map controller 102 searches for the best match between the extended neurons and the extended environmental vector.
[0072] During a fourth step 408 , a fifth step 410 , a sixth step 412 , and seventh step 414 , steps 306 , 308 , 310 and 312 as described with reference to FIG. 3 are performed in the fine tuning phase 400 .
[0073] In an eighth step 416 the fine tuning phase 400 has concluded a first iteration. Further iterations may be initiated or the fine training phase 400 may be terminated by performing a ninth step 418 , during which the extensions on the neurons are removed.
[0074] When the fine tuning is completed the map topology in the map data memory 106 is no longer required, only the value of the neuron-vectors 204 is relevant.
[0075] FIG. 5 shows the labelling phase designated in entirety by reference numeral 500 . The object of the labelling phase 500 is to match each neuron 202 with an acoustic program. The matching is performed on the basis of end-user input, step 504 . That is, every time the end-user changes an acoustic program or maintains an acoustic program for a certain time the training data corresponding to an acoustic program in the training data memory 114 is updated, step 506 .
[0076] A described above with reference to FIG. 1 the training data memory 114 comprises a cyclic buffer with ‘p’ entries for each program, and the cyclic buffer entry corresponding to the identified acoustic situation is fed by ‘1’, and the other entries are fed by ‘0’. More than one value may be fed into the cyclic buffer entries simultaneously depending on the desired training speed. In addition, if fluctuation of the acoustical situation is high all entries corresponding to acoustic situations occurring a time period following the end-user input may advantageously be implemented.
[0077] The winning acoustic program is thus computed for each cyclic buffer entry. As mentioned above with reference to FIG. 1 the index of the cyclic buffer entry which has the highest counter value gives the winning acoustic program. The cyclic buffer entry is then labelled with the computed acoustic program number. If the difference between a highest counter value and a second to highest counter value is below a predetermined threshold the cyclic buffer entry is labelled zero. Every time a cyclic buffer is updated with a new training end-user input the labels are updated, step 508 .
[0078] As soon as the system training is completed the cyclic buffers of the training data may be removed as long as the label for each cyclic buffer is maintained.
[0079] The most probable training scenario is to perform the rough training phase 300 and the fine-tuning phase 400 off-line on a personal computer and the labelling phase 500 during the operating of the hearing aid, since the labelling phase 500 does not need much computing resources. An initial default training set for the labelling phase 500 may however be advantageous. For an off-line fine-tuning phase 400 , the end-user input may be replaced by an objective group assignment. Instead of assigning the environment sensor signals to the acoustic program chosen by the end-user, the environment acoustic situations would be objectively assigned to a signal category (e.g. speech, speech in noise, music, machine noise). Note that the fine-tuning phase 400 optimises the map organisation and is therefore an optional training phase.
[0080] FIG. 6 shows the system 100 in the operation phase 600 comprising a first step 602 during which the environmental vector is recorded, a second step 604 during which the environmental vector is compared with the neuron-vectors 202 and a best match is identified, a third step 606 during which a label is identified for the best match, and finally a fourth step 608 during which the label is communicated to the post-processing unit 118 . | This invention relates to a system ( 100 ) and method for selecting a signal processing program to be executed by a signal processor in a hearing aid. The system ( 100 ) comprises a single layer of neurons ( 200 ) each having one or more neighbours and being arranged in a memory device ( 106 ), wherein each neuron comprises a neuron vector referring to a specific acoustic situation and a neuron label referring to signal processing program associated with said specific acoustic situation. The system ( 100 ) further comprises a sensor adapted to detect an external acoustic situation and to define a sensor vector associated with said external acoustic situation, and wherein a processor ( 102 ) calculates a vector difference between said sensor vector and each of the neuron vectors, identifies that neuron providing the smallest vector difference, and selects a signal processing program referred to by a neuron label of that neuron. | 7 |
FIELD OF THE INVENTION
This invention relates to magnetic bubble memories and more particularly to such memories in which paths for bubble movement are defined by a pattern of ion-implanted regions.
BACKGROUND OF THE INVENTION
Ion-implanted magnetic bubble memories are disclosed in U.S. Pat. No. 3,792,452 of M. Dixon et al., issued Feb. 12, 1974 and U.S. Pat. No. 3,828,329 of R. F. Fischer et al., issued Aug. 6, 1974. In such memories, propagation paths for bubbles are defined by unimplanted regions in the otherwise implanted host layer. Bubbles reside in the implanted region and propagate along the boundary between implanted and unimplanted regions in response to the rotation of an in-plane magnetic drive field. Typically, the unimplanted regions have a contiguous disc geometry, forming a propagation path of interlaced bulges and cusps.
The first of the above-mentioned patents shows the familiar major-minor bubble memory organization. This organization is characterized by a plurality of closed loop propagation paths termed "minor loops" and at least one "major" path. A bubble generator and detector are associated with the major path and data (magnetic bubbles) move between the ends of the minor loops and the major path typically at transfer gates.
Transfer gates generally are defined by an electrical conductor which, when pulsed, causes bubbles to move to one end of the minor loops from associated positions on the major path. There are disadvantages associated with the conventional conductor controlled transfer gates. Long conductor lines, necessary in large chips, are not desirable because of yield loss due to conductor defects, and the need for high voltage pulse generators. Also, there may be stress related conductor crossing problems and the conductor must be precisely aligned with specific portions of the implant pattern to achieve transfer.
BRIEF DESCRIPTION OF THE INVENTION
This invention is directed at a transfer gate arrangement for ion-implanted magnetic bubble memories which is controlled by reversal of the direction of rotation of the in-plane drive field. The transfer gate is formed as part of the ion-implantation pattern that forms the propagation paths and requires no conductor overlay.
The invention utilizes the observation that a narrow gap between unimplanted discs or ends of an ion-implanted contiguous disc propagation track can have the property of allowing magnetic bubbles approaching from one direction to pass through freely, while appearing as a cusp to bubbles approaching from the opposite direction. This anisotropy between directions of approach is due to the threefold anisotropy of the (111) oriented magnetic garnet layer.
This observation has already been exploited to achieve a merging of two paths, as disclosed in copending application Ser. No. 99,556 for T. J. Nelson and R. Wolfe, now U.S. Pat. No. 4,276,614. The present invention makes use of this property in a bubble transfer controlled by a brief reversal of the direction of rotation of the in-plane field.
In one embodiment, a single unimplanted "idler" disc is offset from a gap separating two paths. The gaps between the idler disc and the two paths are aligned with preferred magnetization directions of the implanted area and form a bidirectional transfer gate. A bubble in a first path passes through the gap between the first path and the idler disc. The direction of rotation of the in-plane field is then reversed and the bubble approaches the same gap from the other side. This time the gap appears as a cusp and the bubble transfers to the idler disc. Further reverse rotation of the in-plane field propagates the bubble around the disc through the gap between the disc and the second path. At this point, the direction of the in-plane field is once again reversed. The bubble approaches the second gap, propagates across the gap as across a cusp, and completes the transfer to the second path.
Another embodiment comprises a major-minor organization with separate unidirectional transfer gates at the ends of the minor loops. Here the idler is no longer a simple disc but it performs the transfer function.
A "hybrid" transfer gate employing both conductor and reverse rotation control is also shown. Here, the major path is formed by a series of multistage unimplanted islands separated by gaps. Transfer-in is accomplished by pulsing the conductor to drive the bubbles through the gaps and onto the minor loop. Transfer-out is accomplished by a reverse rotation transfer without conductor assistance. This transfer-in gate has the advantage that there is no net position gain or loss in the transfer-in/transfer-out sequence, (that is bubble position with respect to associated vacancies) so that with appropriate numbers of major and minor loop stages, a block of data may be transferred out of the minor loops and propagate around the major loop an arbitrary number of times before being transferred back to its proper place on the minor loops. Consequently any power failure recovery scheme need not be constrained to advance a block of data only to the first arrival at the transfer-in gates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a bubble memory in accordance with this invention;
FIG. 2 shows a prior art configuration for a merge port;
FIG. 3 shows a top view of a hypothetical ion-implanted pattern defining three merge gap orientations;
FIGS. 4 and 5 are enlarged top views of portions of the memory of the type shown in FIG. 1 demonstrating various embodiments of this invention; and
FIG. 6 is an enlarged top view of an alternative memory.
DETAILED DESCRIPTION
FIG. 1 shows a magnetic bubble memory 10 similar in type to one shown in the above-mentioned application of T. J. Nelson and R. Wolfe including a host layer 11 of a material in which magnetic bubbles can be moved. Bubbles are moved in layer 11 in closed loops l 1 , l 2 . . . and l k , the minor loops, and in a single loop ML, the major loop.
Permanent storage of data is provided by the minor loops. The major loop, on the other hand, provides for access to the minor loops of substitute data from a bubble generator and for read out of addressed data at a detector. In this connection, the generator comprises an electrical conductor 12 connected between a generate pulse source 14 and ground operative under the control of control circuit 15 to provide a pulse selectively during each cycle of a rotating in-plane propagation drive source represented by block 17. The detector similarly comprises, for example, a conductor 18 shown connected between utilization circuit 19 and ground.
Bubbles are maintained at a nominal diameter by a bias field supplied by source 20.
We will adopt the convention that data, generated at 12, moves counterclockwise about loop ML to transfer gates (G) at locations at the top ends of minor loops l i (as viewed) in response to successive rotations of the in-plane field (propagation cycles). Bubbles are transferred in and out of the minor loops in a manner to be described below.
The control of the transfer function as well as the generator, propagation and detector operation is derived from a master clock in accordance with well understood principles. Such circuitry along with an address register is considered to be included within control circuit 15.
The general organization of the memory of FIG. 1 thus can be seen to involve the generation of a bubble pattern at 12 for later storage in the minor loops by transfer at the transfer locations. Also involved is the transfer-out of addressed data from the minor loops by a similar transfer-out operation. The data advances to detector 18 for applying signals representative of the bubble pattern to utilization circuit 19. The selected data moves counterclockwise along loop ML until a later transfer-in operation occurs. This later transfer operation moves the data back into vacancies at the top of the minor loops as viewed.
In this connection, it is helpful to recall that bubbles usually are moving synchronously in all the loops of the memory. When a transfer-out operation occurs, vacancies are left in the addressed bit locations in the minor loops. Those vacancies move about the minor loops as the transferred data move to detector 18 and thereafter move in loop ML. The number of stages in the minor loops and the number in the major loop are chosen so that data transferred out or data generated at 12 arrive at the top end of the minor loops synchronously with those vacancies.
We are concerned herein primarily with a conductorless strategy for implementing the transfer-in and the transfer-out operation. In the embodiment of FIG. 1 both transfer operations occur at the top of the minor loops at transfer locations (or gates) designated G in the figure. The implementation requires an arrangement of ion-implanted regions at each gate. Transfer is responsive to variations in the normal cycle of the propagation drive field supplied by source 17 under the control of control circuit 15. The variation is initiated by the selection of an address for reading out a stored word or by a write operation for storing a substitute word at a selected address. In either case, transfer timing circuit TTC alters the normal propagation sequence in a manner to be described. At this juncture in the description it should be apparent that we are directing attention to ion-implanted magnetic bubble memories of the major-minor type wherein transfer gates between the major path and the minor loops also are defined by ion-implantation and are responsive to controlled deviations (viz: reversals) in a normal cycle of the propagation drive field.
FIG. 2 shows a prior art arrangement which demonstrates the principle upon which this invention is based. The figure shows a merge between two paths P 1 and P 2 defined at the periphery of contiguous discs of unimplanted material in an otherwise implanted layer. Paths P 1 and P 2 are separated by a gap which has an axis which aligns with one of the axes of symmetry of the magnetic garnet layer in which the discs are formed. This merge is shown in the above-mentioned patent of Nelson and Wolfe and for an 8μ period circuit, the gap is 2μ wide. The arrows show the direction of propagation for a bubble in the vicinity of a gap for a counterclockwise rotating in-plane field. Bubbles on the upper side of path P 2 pass freely through the gap and simply propagate around path P 2 . Bubbles approaching the gap from path P 1 , on the other hand, enter the gap from below, proceed as if a cusp were present and continue on a horizontal path to path P 2 . Bubbles that transfer onto path P 2 in this way are then trapped on that path and will propagate around path P 2 . If the direction of rotation of the in-plane field is reversed, bubbles will propagate in the opposite direction, but bubbles approaching the gap from above will still pass through freely and those approaching from below will proceed as if a cusp were present. In this way, bubbles are "trapped" on path P 1 . In FIG. 2, the bottom side of the path is referred to as the strong side and the top side of the path is referred to as the weak side.
Because the (111) magnetic garnet layer has a threefold anisotropy, symmetry considerations indicate that gaps with orientations differing from that in FIG. 1 by ±120 degrees will display analogous behavior. FIG. 3 shows these three merge gap directions, for a downward orientation of the (211) axis consistent with the arrangement of propagation loops shown in FIG. 1. Imaginary discs 21, 22, 23, and 24 are separated by gaps 26, 27, and 28 which are oriented at 120 degrees to each other. The arrows indicate the directions in which bubbles pass freely through gaps. This figure can be used as a reference for FIGS. 4-6 to determine the behavior of a bubble at a gap. As an example of bubble motion with respect to gaps in this type of configuration, consider a bubble at point x of disc 21. If the drive field rotates counterclockwise, the bubble moves counterclockwise along the periphery of disc 21 and approaches gap 26. As indicated by the arrow, it passes through the gap. Thus, in a field rotating counterclockwise, a bubble originating at point x simply propagates continually around disc 21. Consider, however, a bubble at point x in a clockwise rotating field. This bubble approaches gap 26 from the right, but rather than passing through, it proceeds as if the gap were a cusp and transfers to disc 24. The bubble next encounters gap 27. We see that it passes through this gap, and then propagates clockwise around disc 24. Suppose, however, that when the bubble after having passed through gap 27, is at point y on disc 24, the direction of rotation of the drive field is reversed. The field now rotates counterclockwise and the bubble "backs up" and approaches gap 27 again. This time, however, it approaches from the "strong" side and proceeds as if the gap were a cusp, transfers across the gap to disc 23, where it remains as long as the field rotates counterclockwise.
FIG. 4 shows enlarged a top view of a portion of the transfer gate region 29 of the memory of FIG. 1. A pattern of unimplanted contiguous discs is arranged to define major path ML and minor loops l 1 , l 2 , and l 3 as shown. FIG. 4 also shows a circular arrow 30 directed in a counterclockwise direction and representing the drive field vector as it sweeps through the 0, 90, 180, and 270 reference directions as marked. It will be demonstrated now that the pattern of ion-implanted regions of FIG. 4 is operative to transfer a pattern of bubbles between major path ML and the minor loops.
Bubbles move counterclockwise in the various paths in response to a counterclockwise drive field. Bubbles in loop ML simply propagate around the loop, passing freely through gaps 35. Similarly, bubbles in the minor loops remain in those loops and pass freely through gaps 36. Transfer from the major loop to the minor loops requires a properly timed reversal of the direction of rotation of the drive field. The reverse rotation for achieving transfer into the minor loops is initiated when the drive field is in the 270-degree orientation shown in FIG. 4, bubbles in the major loop having just passed through gap 35. The bubbles in the major loop, in response, move clockwise about associated discs 38 to associated gaps 36. The bubbles pass through associated gaps 36 and, after one and one half clockwise rotations of the in-plane field, come to rest at the 90-degree positions on associated discs 38. Now the field reverses again to resume counterclockwise rotation. The bubbles, encountering gaps 36 now from the "merge" side, cross the gaps and transfer to the minor loops for continuing counterclockwise movement thereabout.
Transfer from the minor loops to the major loop is similar, with reverse rotation starting at a 90 degree orientation and ending at at a 270 degree orientation. In this transfer-out operation, a bubble in a minor loop passes through gap 36. When it reaches the 90-degree orientation on disc 41, circuit TTC of FIG. 1, under the control of control circuit 15, reverses the field and the bubble, now moving clockwise, transfers to the associated disc 38. When the bubble has passed through gap 35, circuit TTC resumes counterclockwise rotation of the drive field and transfer to the major loop is completed.
In this reverse rotation transfer process, the neighbors of the transferred bubbles on both the upper and the lower loops suffer no net disturbance, simply moving back and forth synchronously with the field rotation changes. It should be clear at this juncture that a controlled reverse rotation excursion of the bubble drive field causes movement of a bubble pattern from the major loop to the minor loops and vice versa depending on the direction of the drive field when the excursion commences. Consequently, a pattern of bubbles generated by pulses in conductor 12 of FIG. 1 can be moved into vacancies in the minor loops and bubbles in the minor loops can be moved into the major loop for detection by conductor 18 for applying signals to circuit 19 all under the control of control circuits 15 as has been stated hereinbefore.
A "major-minor" bubble memory with transfer-in and transfer-out functions being carried out at the same end of the minor loops is implemented with what is commonly called a "bilateral" transfer. Often, the separate transfer functions are implemented at opposite ends of the minor loops. In cases like these, the major loop encompasses the minor loops at both ends forming a G-shaped path or a double U-shaped path as is now well known.
FIG. 5 shows a top view of an ion-implanted pattern which defines a minor loop field with separate transfer-in and transfer-out functions at opposite ends of the minor loops. The transfer implementation in each instance is designed either for transfer-in or for transfer-out but not both. They are not bilateral transfer implementations as shown in FIG. 4. The figure includes minor loops l 1 -l 6 with major loop ML encompassing the minor loop field both on the transfer-out side and on the transfer-in side. Unimplanted islands (double discs) 81 to 86 and 91 to 96 define transfer-out and transfer-in locations, respectively. We will first consider the motion of a bubble being transferred out of minor loop l 2 and the synchronous motion of a bubble at the lower end of loop l 1 . We will assume our two bubbles 99 and 100, start in positions 101 and 102. The field rotates counterclockwise until it points in the 270 degrees direction as shown in FIG. 4. Bubble 99 has passed through gap 110 and occupies position 112. Bubble 100 occupies position 115 after having passed through gap 116. The direction of rotation of the in-plane field now reverses for one and one half cycles. During this time, bubble 99 crosses gap 110, moving along island 92 and passing through gap 118 to occupy position 119 while bubble 100 crosses gap 116 and comes to rest on cusp 120. The bubble (100) does not pass through gap 121. Counterclockwise rotation of the field is resumed and after one and one half rotations, bubble 99 has transferred to loop 12 across gap 118 and occupies position 122 while bubble 100 has moved back across gap 116 to loop l 2 . We see that even with a bubble at the end of the minor loop, no improper transfer-out occurs during the transfer-in process. However, since the illustrative transfer-out process requires two and one half reverse rotations, it is necessary to arrange that the write line is empty during transfer-out so that unwanted simultaneous transfer-in will not occur.
Transfer-out occurs as follows: A bubble, originally occupying position 130 on minor loop l 4 passes through gap 116 to position 115. The field reverses and after two and one half reverse rotations from 270 degrees to 90 degrees, brings the bubble through gap 121 to position 131. Normal, counterclockwise rotation resumes and the bubble crosses gap 121 to island 142 which is part of the major loop. The bubble propagates counterclockwise along the periphery of this island, freely passing through gap 153 and then propagating along the lower sides of island 142 moving to the right as viewed along the adjacent like-shaped islands.
FIG. 6 shows a "hybrid" transfer gate which employs both conductor and reverse rotation-controlled transfer-in. The figure shows the lower ends of minor loops l 1 -l 4 as well as a major path ML formed by unimplanted islands 180-183 separated by gaps 185-187. Also shown is transfer conductor 190. Normal bubble propagation is from left to right along major path ML formed by the lower edges of islands 180-183. Bubbles encountering gaps 185-187 treat them as cusps because, as we see from FIG. 2, the direction of free passage is from top to bottom through these gaps. Transfer-in is accomplished by pulsing transfer conductor 190, connected to a transfer pulse source (not shown) to drive bubbles through gaps 185-187. No reverse rotation is needed, because bubbles, once moved above the gaps, thereafter simply move along the tops of islands 180-183, treat gaps 195-198 like cusps, and thereby transfer to minor loops l 1 -l 4 . Transfer-out is accomplished by three cycles of reverse rotation. Reversal of the in-plane field causes a bubble at position 200, for example, to cross gap 195 as if it were a cusp, propagate around island 180 and pass through gap 185 and come to rest in cusp 201. When counterclockwise field rotation is resumed, the bubble then propagates along major path ML from left to right.
This hybrid transfer gate has the advantage that, contrary to what happens in the other reverse rotation gates, there is no net gain or loss in the transfer-in/transfer-out combination, so that with appropriately adjusted major and minor loop counts, a block of data may be transferred-out of the minor loops and propagate around the major loop an arbitrary number of times before being transferred back to its proper place in the minor loops. A power failure recovery scheme is therefore not constrained to advance the block only to the first arrival at the transfer gates. | Transfer between paths in ion-implanted magnetic bubble memories has been achieved without the use of transfer conductors. The transfer mechanism takes advantage of the three-fold anisotropy of the implanted drive layer which makes it possible for bubbles to pass freely through gaps in one direction while being obstructed from passing through in the other direction. Transfer is controlled by a brief reversal of the direction of rotation of the in-plane field. In one embodiment, a bidirectional transfer gate is employed. Configurations using unidirectional gates and hybrid gates using conductor and reverse-rotation controlled transfer are also shown. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for evening (levelling) the fiber lap fed to a textile fiber processing machine such as a card, a roller card unit or the like, having a licker-in, a feed roller arranged upstream of the licker-in as viewed in the direction of material feed and a feed table cooperating with the feed roller. The levelling apparatus includes a measuring member for sensing the thickness of the fiber material drawn into the fiber processing machine and a control device which receives signals from the measuring member and which is connected with the drive motor for the feed roller for regulating the rpm of the latter as a function of the sensed thicknesses.
In an apparatus of the above-outlined type, as disclosed, for example, in French Pat. No. 2,322,942, underneath the stationarily supported feed roller there is provided a stationary support on which a plurality of sensor levers (feed table) are movably held. One end of each sensor lever is in the immediate vicinity of the licker-in and is spring-biased against the feed roller. The other end of each sensor lever is coupled to a measuring device which senses and integrates the displacements of the sensor levers as they move dependent upon the thickness of the fiber material which passes through.
It is a disadvantage of the above-outlined arrangement that as the fiber material is being taken over from the feed roller by the licker-in, the working forces (tearing forces) of the licker-in have an effect on each sensor lever and consequently, the measuring results may be distorted. It is a further disadvantage of such a prior art arrangement that the location of measurement in the nipping zone (clamping zone) between the feed roller and the sensor lever extends over a relatively long region (from the beginning of the nipping zone to the end of the sensor lever) in which the feed roller is essentially facing the sensor lever and, as a result, the measuring location is not unequivocally determined. In this arrangement the feed table is formed of a great number of spring-biased sensor levers which are coupled to a "piano key" system which is structurally very complex.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus of the above-outlined type with which the discussed disadvantages are eliminated and which, with particularly simple means prevents undesired forces from being applied to the measuring member and by means of which the measuring location can be unequivocally determined.
These objects and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for levelling the thickness of a running fiber lap fed to a textile fiber processing machine, includes a feed roller having a generally horizontal longitudinal axis and a feed table cooperating with the feed roller by defining therewith a nip through which the fiber lap passes. The fiber processing machine further includes a motor connected with the feed roller for rotating the feed roller, a lap thickness measuring device including a sensor element cooperating with the feed roller and undergoing excursions in response to thickness variations of the fiber lap running between the feed roller and the sensor element and a control device connected to the measuring device for receiving signals representing the excursions. The control device is connected to the motor for applying rpm control signals thereto as a function of the thickness variations. The sensor element is separate from, and is movable relative to, the feed table, and the feed table has an aperture, and the sensor element cooperates with the feed roller through the aperture.
By virtue of the fact that the feed table is arranged between the sensor element of the measuring member and the licker-in, a distance is provided between the measuring location and the licker-in.
It is an advantage of this arrangement that while the licker-in may exert a force on the fiber material supported by the feed table, there will be no adverse effect on the fiber material lying on the sensor element, particularly at the measuring location. It is a further advantage of the invention that the measuring location extends in the clamping (nipping) zone between the sensor element of the measuring member and the feed roller over a very short region or only over a line extending parallel to the axis of the feed roller or even only over a dot-like area. In this manner, in contradistinction to prior art arrangements, the position of the measuring location may be positively determined whereby a constant path between the measuring location and the transfer location of the fiber material to the licker-in (working location) is ensured.
Dependent upon whether, as a result of the rpm regulation more or less fiber material reaches the working location, the licker-in takes over a greater or lesser amount of fiber material. By virtue of the fact that the sensor element is independent from the feed table, the structure of the apparatus is significantly simplified.
According to a further feature of the invention, the aperture is constituted by a cutout which is provided in the feed table and which may be closed on each side or may be open at one side (that is, at one of the short outer edges). Preferably, the cutout is rectangular wherein the long edges of the cutout extend parallel to the width of the feed table (that is, parallel to the feed roller axis). According to a further feature of the invention the measuring member comprises a rectangular sensor element whose long edges extend parallel to the width of the feed table while its short edges are oriented perpendicularly to the direction of material feed (working direction). By virtue of such a design measurements at several measuring locations may be performed in a structurally simple manner simultaneously over the width of the fiber material with a simultaneous summation (integration) of the measuring values.
According to a preferred embodiment of the invention, two to four sensor elements are provided which is a structurally simple solution and which permits the integration of several measuring values over wide sensor elements.
According to advantageous further features of the invention,
the outer end of the sensor element extends approximately as far as the vertical axial plane of the feed roller as viewed in the direction of the licker-in;
the sensor element is supported on a stationary rotary bearing;
the rotary bearing cooperates with a force-exerting element, such as a counterweight or a spring;
the sensor element is vertically displaceably supported;
the sensor element is resiliently supported at its two opposite outer ends;
the sensor element is supported on a holding member;
the sensor element is supported for rotation about a horizontal axis;
the sensor element or the support member has at least one plunger core (armature) with a plunger coil; and
the measuring element of the measuring member is an analog, no-contact distance sensor.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view of a carding machine incorporating the invention.
FIG. 2a is a schematic side elevational view of a preferred embodiment of the invention.
FIG. 2b is a sectional view taken along line IIb--IIb of FIG. 2a.
FIG. 2c is a top plan view taken along plane IIc--IIc of FIG. 2a.
FIG. 3 is a perspective view of further details of the preferred embodiment.
FIG. 3a is a schematic side elevational view of the structure shown in FIG. 3, illustrating further details.
FIG. 3b is a schematic front elevational view of FIG. 3a.
FIG. 4 is a schematic front elevational view of another preferred embodiment of the invention.
FIG. 5 is a schematic front elevational view of still another preferred embodiment of the invention.
FIG. 6 is a schematic perspective view of yet another preferred embodiment of the invention.
FIG. 7 is a perspective view of still another preferred embodiment of the invention.
FIGS. 7a and 7b are sectional details of the construction illustrated in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, there is illustrated therein a carding machine which may be, for example, an "EXACTACARD DK 715" model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany. The carding machine has a feed roller 1, a feed table 2 formed by parts 2a, 2b, a licker-in 3, a main carding cylinder 4, a doffer 5, stripping rollers 6, crushing rollers 7 and 8, a web guide element 9, a sliver trumpet 10, calender rollers 11 and 12 as well as travelling flats 13.
The various cylinders and rollers of the illustrated carding machine normally rotate in the direction of the curved arrows drawn into the respective component. While the invention is shown and described in connection with a carding machine, it is to be understood that the invention may find application in other types of textile processing machines, such as roller card units, beaters, cleaners or the like.
Th feed roller 1 is stationarily supported for rotation. The feed table 2 is a one-piece component formed of a rearward portion 2a and a frontal portion 2b. Between the portions 2a and 2b there is provided a cutout 19. The terminal edge of the feed table portion 2b oriented towards the feed table portion 2a reaches slightly beyond the vertical axial plane 1a of the feed roller 1 in the direction of the feed plate portion 2a. The other, opposite end of the feed table portion 2b extends into a gap defined between the feed roller 1 and the licker-in 3. That end of the feed table portion 2a which is oriented towards the feed table portion 2b terminates at a short distance in front of the vertical axial plane 1a of the feed roller 1 as viewed in a direction towards the licker-in 3.
Below the feed roller 1 there is provided a sensor element 20 which is biased in the direction of the feed roller 1 by a compression spring 14 which is in engagement with the underside of the sensor element 20 and with a fixed countersupport 14b.
The sensor element 20 is movably supported--in a manner described later--for executing excursions as a function of the thickness of the fiber material 15 which passes through the space bounded by the sensor element 20 and the periphery of the feed roller 1. With the sensor element 20 there is associated a measuring member 16 which measures the displacements of the sensor element 20 and which applies its signals to a control device 17 which, in turn, is connected to a drive motor 18 of the feed roller 1. As the thickness of the running fiber lap varies, the sensor element 20, being in contact with the fiber lap surface, deflects accordingly. The magnitude of such deflection is registered by the measuring member 16 and a representative signal is applied to the control device 17 which, accordingly, causes the drive motor 18 for the feed roller 1 to rotate faster or slower.
Turning to FIG. 2a, in the fiber lap feeding device formed of the feed roller 1 and the feed table 2 cooperating therewith, there is provided the feed table portion 2a over which the fiber material is guided towards the feed roller 1. The feed table 2, as well seen in FIG. 2c, is a one-piece construction and has two apertures formed as rectangular cutouts 19a and 19b. The long edges u', u" and v', v" of the cutouts 19a and 19b, respectively, are oriented parallel to the width of the feed table 2, that is, parallel to the axis 1b of the feed roller 1. The short edges x', x" and y', y" of the cutouts 19a and 19b, respectively, extend in the working direction, that is, parallel to the feed direction of the fiber lap 15. A sensor element 20a and 20b is accommodated in the area of the cutouts 19a and 19b, respectively. The sensor elements 20a and 20b have a rectangular configuration wherein, similarly to the edges of the cutouts 19a and 19b, the long sensor element edges extend parallel to the width dimension and the short sensor element edges are oriented in the working direction, that is, parallel to the direction of feed of the fiber material.
The frontal edge of each sensor element 20a and 20b extends approximately to the vertical axial plane 1a of the feed roller 1 as viewed in the direction towards the licker-in 3.
Turning to FIG. 2b, the sensor elements 20a and 20b are illustrated in section and during sensing operation in the respective cutouts. The feed table 2 has narrow lateral bounding portions 2' and 2". The sensor element 20a projects through the cutout 19a while defining bilateral gaps 19a' and 19a" therewith. The sensor element 20b projects through the cutout 19b while defining bilateral gaps 19b' and 19b" therewith. The fiber lap 15 is supported on the feed table 2 and is in a contacting relationship with the respective upper faces of the sensor elements 20a, 20b.
The sensor elements 20a and 20b are of identical construction, and in FIGS. 3, 3a, 3b, 4, 5 and 6 a single sensor element designated with the reference numeral 20 will be described in more detail.
Turning to FIG. 3, the sensor element 20 is supported in a holding bar 21 by means of a pin-like extension 22 situated at one end thereof. The long narrow side of the sensor element 20 oriented towards the holding bar 21 is provided with a blind bore which receives a ball bearing 23 into which extends the end portion of the pin 22 of the holding bar 21. By virtue of this arrangement the sensor element 20 is pivotally supported for swinging motions about the generally horizontal axis of the support pin 22 as indicated by the double-headed curved arrow A.
The holding bar 21, in turn, is pivotally supported in a stationarily held bearing 23' providing for a pivotal motion of the holding bar 21 as indicated by the curved double-headed arrow B about a generally horizontal axis oriented perpendicularly to the axis of the pivot pin 22. By virtue of the swinging motion of the holding bar 21, the sensor element 20 is movable in a vertical plane as indicated by the double-headed arrow C.
Turning to FIG. 3a, the holding bar 21 is, at its end remote from the pin 22, engaged at its top by a compression spring 24 which is supported stationarily and which urges the assembly formed of the sensor element 20 and the holding bar 21 clockwise about the horizontal axis of the bearing 23'. With the holding bar 21 there is associated a measuring element 16 which is formed of a stationary plunger coil 16" and a plunger core (armature) 16' affixed to the holding bar 21 and is thus movable within and with respect to the plunger coil 16". The measuring element 16 thus constitutes an inductive, no-contact path sensor/distance measuring device. A stationary abutment 21' is provided above the holding bar 21 to limit the pivotal motion of the assembly 20, 21 in a clockwise direction to thus prevent the sensor element 20 to contact the periphery of the feed roller 1.
Further, as shown in FIG. 3b, at the two longitudinal opposite ends of the sensor element 20 further measuring elements 16a and 16b are arranged which may structured identically to the measuring element 16.
Turning to the embodiment illustrated in FIG. 4, the sensor element 20 is supported on the underside at its opposite longitudinal ends by compression springs 25a, 25b and the feed table 2 is rigidly held at 25c. Further, the feed roller 1 has bearing which is resiliently supported at the machine frame by means of a spring 26 whereby the feed roller 1 may execute vertical excursions.
In the embodiment illustrated in FIG. 5, the feed roller 1 is radially immovably supported while the feed table 2 is, at opposite sides, mounted resiliently by means of springs 27 (only one shown) to thus permit the feed table 2 to execute vertical excursions towards and away from the feed roller 1. The sensor element 20 is supported by springs 25a and 25b similarly to the embodiment shown in FIG. 4. Thus, while the feed table 2 and the sensor element 20 are caused to perform excursions by the same source of force (namely, the radially oriented force transmitted by the fiber material passing between the feed roller 1 on the one hand and the feed table 2 and the sensor element 20, on the other hand), the feed table 2 and the sensor element 20 are arranged to be movable independently from one another.
Turning to the embodiment illustrated in FIG. 6, the sensor element 20 shown therein has in the mid portion of its underside a support post 28a whose free outer end remote from the sensor element 20 has an arcuate, convex configuration. A carrier bar 28, supported at its underside on springs 31a, 31b, has an upper concave, cradle-like supporting surface which receives the complementally configured convex face of the support post 28a of the sensor element 20 and is supported thereon for arcuate sliding motions indicated by the double-headed curved arrow D. The support bar 28, guided by vertical guides 29 on both ends of the support bar 28 (only one guide 29 is shown for clarity) is adapted to reciprocate vertically as indicated by the double-headed arrow E.
Turning now to FIG. 7, the structural embodiment shown therein illustrates the feed roller 1 rotatably supported in two bearings 33a, 33b mounted on machine stand walls 32a, 32b, respectively. The feed table 2 is supported by two bearings 34a, 34b with the intermediary of two two-part connecting pieces 2c, 2e and 2d, 2f, respectively. As shown in FIG. 7a, the feed table 2, by virtue of its support in bearings 34a, 34b is swingable in a vertical plane about a horizontal axis oriented parallel to the axis 1b of the feed roller 1 as indicated by the curved arrow F in FIG. 7a. The bearings 34a and 34b are connected to one another by a rigid, stationary shaft 36.
The shaft 36 is spacedly and coaxially surrounded at its opposite end portions by sleeves 37a, 37b which are rotatable about and with respect to the shaft 36 as indicated by the arrow G. The sleeves 37a, 37b are connected with respective holding blocks 38a, 38b which support respective lever arms 39a and 39b whose outer end holds respective counter weights 40a 40b. To the holding blocks 38a, 38b, at their side oriented away from the lever arms 39 a, 39b there are attached holding bars 21a, 21b which pass through a rear side aperture 2g, 2h of the feed table 2. At the ends of the holding bars 21a, 21b, the respective sensor elements 20a, 20b are rotatably mounted to be swingable about a horizontal axis as illustrated in FIG. 3 and indicated with the arrow A. At the outside face of the sleeves 37a, 37b there is attached a respective measuring arm 41a, 41b connected with an armature 42a, 42b of a measuring member 16a, 16b, respectively. Each armature 42a, 42b cooperates with an associated plunger coil 43a, 43b. On the upper sides of the bearing connecting members 2e, 2f there is secured a respective hollow support element 44a 44b, which, as illustrated in FIG. 7b, accommodates respective disc spring stacks 45 and guide pins 46. This arrangement provides that the feed table 2 is resiliently supported by the support elements 44a, 44b on the top face of the housing block of the bearing members 34a, 34b.
Thus, according to the embodiment illustrated in FIG. 7, similarly to the embodiment schematically shown in FIG. 5, the feed table is movable. The purpose of such mobility is to achieve a possibly uniform pressing of the running fiber material against the feed roller 1 even in case of thickness fluctuations thereof. The pressing force is high and is necessary for a positive material feed and for clamping the fiber material advanced to the edge of the work zone, that is, to the transfer location between the feed roller 1 and the licker-in 3. Such a clamping prevents the licker-in 3 from tearing out large chunks of fiber material from the advanced fiber lap portion. The clamping determines the magnitude of the pressing force; the advancing of the material in response to such a force is of secondary significance. From the point of view of advancing the fiber material such pressing force could be of lesser value. The pressing arrangement between the feed table 2 and the feed roller 1 does not serve for the thickness determination. In the FIG. 7 embodiment the feed roller 1 is stationarily supported, that is, it is prevented from executing radial excursions. The sensor elements 20a, 20b are, for performing their sensing function, pressed against the feed roller 1 only with a very small force. Such force does not serve for advancing the fiber material; on the contrary, it tends to counteract such transporting force. It is for this reason that the pressing force is as weak as possible and is just sufficient to ensure an unequivocal thickness sensing.
The arrangement of FIG. 7 thus ensures a structural separation between clamping and feeding the fiber material, on the one hand and sensing its thickness, on the other hand, to achieve an optimal dimensioning of forces for the two different purposes which, as explained above, require considerations inconsistent with one another. In this manner the individual tasks (particularly the clamping of the fiber material at the edge of the working zone and the sensing of the thickness of the material) may be separately handled and the necessary tasks performed in a more efficient manner. As a result, a highly sensitive determination of the thickness variation of the running fiber material may be achieved which is not feasible in case the function of material advancing and sensing are combined.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | An apparatus for levelling the thickness of a running fiber lap fed to a textile fiber processing machine, includes a feed roller having a generally horizontal longitudinal axis and a feed table cooperating with the feed roller by defining therewith a nip through which the fiber lap passes. The fiber processing machine further includes a motor connected with the feed roller for rotating the feed roller, a lap thickness measuring device including a sensor element cooperating with the feed roller and undergoing excursions in response to thickness variations of the fiber lap runing between the feed roller and the sensor element and a control device connected to the measuring device for receiving signals representing the excursions. The control device is connected to the motor for applying rpm control signals thereto as a function of the thickness variations. The sensor element is separate from, and is movable relative to, the feed table, and the feed table has an aperture, and the sensor element cooperates with the feed roller through the aperture. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation application of U.S. Ser. No. 11/865,253, filed Oct. 1, 2007, now U.S. Pat. No. 7,381,063 B2, which is a divisional application of U.S. Ser. No. 11/365,366, filed Mar. 1, 2006, now U.S. Pat. No. 7,331,796, which claims benefit of U.S. Ser. No. 60/715,261, filed Sep. 8, 2005.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with United States Government support under Contract No. NBCH3039004, DARPA, awarded by the Defense, Advanced Research Projects Agency, whereby the United States Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the provision of novel and unique Land Grid Array (LGA) interposers, which incorporate the structure of metal-on-elastomer hemi-torus and other geometrically configured electric contacts to facilitate an array of interconnections between diverse electrical components. The invention is further concerned with a method of producing the inventive LGA interposers.
Land Grid Array (LGA) interposers, by way of example, provide an array of interconnections between a printed wiring board (PWB) and a chip module, such as a Multi-Chip Module (MCM), among other kinds of electrical or electronic devices. LGA interposers allow connections to be made in a way which is reversible and do not require soldering as, for instance, in ball grid arrays and column grid arrays. Ball grid arrays are deemed to be somewhat unreliable on larger areas because the lateral thermal coefficients of expansion driven stresses that develop exceed the ball grid array strength. Column grid arrays hold together despite the stresses but are soldered solutions and, thus, do not allow for field replaceability, which is important because it saves the customer or user significant costs in the maintenance and upgrading of high-end computers for which LGAs are typically used.
2. Discussion of the Prior Art
The basic concept of utilizing LGA interposers to provide an array of electrical connections is well known in the technology. In this connection, reference may be made in particular to Hougham, et al., U.S. Patent Publication No. 2005/0106902 A1, which is commonly assigned to the assignee of this application, and the disclosure of which is incorporated herein by reference in its entirety. This publication describes LGA interposers which define structure consisting of metal-on-elastomer type electrical contacts, wherein a compliant contact consists of an elastomeric material structural element partially coated with an electrically conductive material, preferably such as a metal, so as to form the intended electrical contact. However, there is no disclosure nor suggestion of a compliant contact of an LGA interposer type providing multiple points of electrical contact for each gridpoint in a configuration, such as is uniquely provided by the present invention.
Johnescu, et al., U.S. Patent Publication No. 2005/0124189 A1 discloses an LGA-BGA (Land Grid Array-Ball Grid Array) connector housing and electrical contacts which, however, do not in any manner disclose the novel and inventive LGA interposer metal-on-elastomer structure as provided for herein.
Similarly, DelPrete, et al., U.S. Pat. Nos. 6,790,057 B2 and 6,796,810 B2; and Goodwin, et al., U.S. Pat. No. 6,293,810 B2, describe various types of elastomeric electrical contact systems and devices which, however, do not at all disclose the features and concept of the present inventive metal-on-elastomer LGA interposers and arrays pursuant to the present invention.
SUMMARY OF THE INVENTION
Metal-on-elastomer type LGA contacts, as described hereinabove, have been previously described in Hougham, et al. in which a compliant contact consists of a structural element of a non-conductive elastomer that is coated on a part of its surface with electrically conductive material, which resultingly forms the electrical connection. However, a compliant contact with multiple points of electrical contact for each gridpoint is only disclosed by the present invention, wherein several specific geometries and variants are also described. Among these, a hemi-torus shaped element, such as being similar in shape to one-half of a sliced donut in transverse cross-section) may be oriented concentrically with respect to a via (or proximate thereto), the latter of which passes through an insulating carrier plane to the other side thereof. Metal is deposited onto the external portions of the hemi-toroidal elastomer element in order to form a multiplicity of electrically conductive contacts.
There are two general instances of LGA interconnects made with hemi-toroidally shaped, or other kinds of structural contact elements constituted of elastomeric materials. In the first instance, holes or vias in an insulating carrier plane would first be filled with metal to form solid electrically conducting vias with a surrounding pad or dogbone pad. Onto these pads would be molded both top and bottom elastomeric LGA bodies possessing various shapes, for example, hemi-toroidal. Then in a final step, metal strips would be deposited from the via pad on each side up and over the apex or uppermost ridge of the elastomeric hemi-torus. As illustrated in the drawings, this would then form a continuous electrical path from the highest point on the top hemi-torus shape to the lowest point on the bottom hemi-torus shape at several points for an individual I/O.
In the second instance, the insulating carrier is initially unmetallized with open holes on the desired grid pitch. Then, the top and bottom elastomeric bodies, for instance, hemi-toruses are molded and metallization follows to form the electrically conducting path, as illustrated hereinbelow. In case that during molding, the open hole in the insulator were inadvertently (or purposely) filled with elastomer, (e.g. siloxane), this can be removed in a controlled fashion by a coring or punch step to open a continuous pathway from the top surface to the bottom surface. Metallization can then be deposited on the exposed surface, which is produced thereby in a desired pattern so as to form the electrically conductive pathway.
In addition to the standard two-sided LGA interposer, i.e., on both sides of an insulating carrier phone, a one-sided compliant contact is also generally known in the art, and referred to as a “hybrid” LGA in which the contacts are soldered (ball-grid-array or BGA) to the circuit board but form a compression connection with the module, as in Johnescu, et al., this frequently being referred to as a “hybrid BGA/LGA” or a “hybrid LGA/BGA” interposer.
There are several types of hybrid BGA/LGA's commercially available; however, the present invention describes a new type of hybrid BGA/LGA combining a metal-on-elastomer hemi-toroidally shaped top or upper contact with a solderable (BGA) bottom or lower contact. This provides significant advantages over existing technologies, and examples thereof are presented hereinbelow.
In one preferred embodiment, an insulating carrier plane with regularly spaced through-holes is treated to create a metal pad on top to fill the holes with electrically conducting metal for a through via, and a bottom surface, for example, by electroplating followed by photolithography. This produces a bottom surface with a pad for a BGA connecting to a circuit board. Then molded onto the top surface is a hemi-toroidal shape of an elastomeric material, such as siloxane rubber. The hemi-torus is located concentric to the metal via pad and surrounds it either fully or partly so that the elastomeric inside edge of the hemi-torus either touches the metal via and pad or lies outside the boundary of the via and pad. Then, metal is deposited to form a path of a continuous electrical connection leading from the top of the elastomer hemi-torus to the pad, which connects to the electrically conducting via to the bottom side of the insulating carrier plane creating a continuous conductive pathway from top to bottom. The metal on the elastomer may be distributed over the entire surface, or fabricated to consist of one or more strips connecting the top of the hemi-torus to the via pad. In a preferred embodiment there can be employed three strips, separated by 60 degrees from one another, although other quantities and spacing are shown herein. All of the strips start at the top of the torus, or slightly on the outside edge, and terminate on the pad in the center, this then providing multiple contact points, which is deemed electrically desirable.
Entrapment of air in the center of the hemi-torus is of concern as it could interfere with reliable seating of the electrical contact in compression. This potential concern can be mitigated by forming an opening or venting slit in the side of the torus during or after molding. Alternatively, any concern about entrapped air can be overcome by making the metal strips which extend over the top of the hemi-torus thick enough to extend over the elastomer surface, so that the gap produced between the uncoated area of the hemi-torus and the module bottom when the metal is in contact with the module bottom provides sufficient venting to allow a facile escape of air from the center of the hemi-torus upon actuation.
Another advantage to having multiple discontinuities in the hemi-torus shape resides in that each segment with its metal strip contact can move independently and better accommodate or compensate for non-uniformities in the mating surfaces.
The hemi-toroidal shape of the interposer can be molded from a compliant (rubbery) material onto each I/O position in an array, and metal strips are fabricated on the top surface of this shape so that they will provide multiple electrical pathways from a single chip module pad to a single printed circuit board pad. When this compliant hemi-torus is thus metalized, and preferably provided with discontinuities in the donut wall so that air would not be trapped preventing good contact, and provided that the compliant button stays well adhered to the insulating substrate or plane by virtue of anchoring holes, surface roughening, or surface treatments or coatings, then a uniquely functioning LGA is readily produced.
A structure pursuant to the invention possesses another advantage. For modules or PCBs that have solder balls or other protruding conductive structures, the LGA interposer array can be actuated into the module/PCB sandwich without the need for any separate alignment step or alignment structures. The ball will nest in the hemi-torus structure and center and stabilize itself with respect to any lateral motion in the x-y directions.
This provides another advantage which may sometimes be invoked, in that a module, which has had solder balls attached thereto, it in preparation for an ordinary BGA solder reflow step could instead be redirected on the assembly line for utilization in an LGA socket. Thus, a single product number part (balled module) could be used in two separate applications: 1) BGA soldering and 2) LGA socketing.
Such torus structures could be made by molding where the molds are made by drilling or machining with a router-like bit. Alternatively, it could be made by chemically or photoetching of the mold material utilizing a mask in the shape of a torus structure. The mask could be made by photolithography directly on the mold die or could consist of a premade physical mask (such as from molybdenum sheet metal) that was separately formed by photolithography and then applied to the mold die.
Another embodiment of this invention utilizes a hemi-torus that has been divided into three or four sections, each of which have been metalized to provide separate electrical paths, and whereby each section can respond mechanically independently when contacted with a pad or solder ball and can thus more reliably form a joint. Moreover, preferably a small space between these sections is created to allow gas to escape freely.
Pursuant to yet another embodiment, a number of the divided sections of a single hemi-torus can be made taller to provide a lateral stop for the case when a balled module is loaded preferably from one side thereof.
According to another embodiment, a wall shape of the sectionally-divided hemi-torus curves back in and under to form a nest so that when a solder ball is brought into contact therewith, it can be pressed down into the nest and snapped into place, or the shape could be curved simply to best nest a solder ball held in place there against.
As described in another embodiment, the I/O consists of multiple hemi-toroidal conic sections or domes that are fabricated into a group to service a single I/O. Each of these domes is metalized separately so that when contact is made with a module pad, redundant electrical paths are formed. The different contacts can also act independently mechanically thus being better able to accommodate local non-uniformities. A further modification would be to make a portion of the hemi-toroidal domes in such a group higher in the z-direction, thus providing a mechanical stop for cases where a balled module is loaded in part from one side, and thus able to constitute an alignment feature.
In the above embodiments, the structures and methods described can be applied to either single sided compliant LGAs (aka hybrid LGA), i.e., on one side of the carrier plane only, or to double sided LGAs. Further, they can be applied to hybrid cases where the corresponding metal pad is either directly in line with the center axis of the upper contact or may be offset therefrom.
As shown in another embodiment, the compliant structures are in a linear form rather than based on a torus or groups of domes. From a linear compliant bar, or alternatively a sectioned bar, multiple contact strips can be formed for each I/O. Further, the multiple metal contact strips could be located on different linear bars for a given I/O. Various arrangements could include multiple metal strips on the same linear section of compliant material, or on different adjacent linear bars in a line, or on different linear bars on either side of the central I/O via.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be made to the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings; in which:
FIG. 1 illustrates generally diagrammatically, a metal-on-elastomer LGA interposer array, shown in a transverse sectional view, pursuant to a first embodiment of the invention;
FIG. 2A illustrates a modified embodiment of the metal-on-elastomer LGA interposers, shown in a transverse enlarged sectional view;
FIG. 2B illustrates a perspective view of the LGA interposer array of FIG. 2A ;
FIG. 3 illustrates a perspective view of metal-on-elastomer LGA interposers;
FIG. 4 illustrates a transverse enlarged cross-sectional view of the LGA interposers of FIG. 3 ;
FIG. 5 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 6 illustrates a transverse enlarged cross-sectional view of the interposer array of FIG. 5 ;
FIG. 7 illustrates a perspective view of a further embodiment of a metal-on-elastomer LGA interposer array;
FIG. 8 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 7 ;
FIG. 9 illustrates a perspective view of a still further embodiment of a metal-on-elastomer LGA interposer array;
FIG. 10 illustrates a perspective view of a further embodiment of an LGA interposer array, which is similar to that illustrated in FIG. 7 ;
FIG. 11 illustrates a further embodiment in a perspective view of an LGA interposer array showing a modification relative to that shown in FIG. 10 ;
FIG. 12 illustrates a perspective representation of a further LGA interposer array, which is somewhat similar to that of FIG. 10 ;
FIG. 13 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 12 ;
FIG. 14 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 15 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer array of FIG. 14 ;
FIG. 16 illustrates a transverse enlarged cross-sectional view of an embodiment which is somewhat similar to that of FIG. 14 ;
FIG. 17 illustrates a perspective view of a further embodiment of an LGA interposer array;
FIG. 18 illustrates a transverse enlarged cross-sectional view of the LGA interposer array of FIG. 17 ;
FIG. 19 illustrates a perspective view of a modified embodiment of the LGA interposer array, relative to that shown in FIG. 17 ;
FIG. 20 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer array of FIG. 19 ;
FIG. 21 illustrates a modified arrangement consisting of linear bars of metal-on-elastomer contacts shown in a perspective representation;
FIG. 22 illustrates a transverse enlarged cross-sectional view of a portion of the LGA interposer arrangement of FIG. 21 ; and
FIGS. 23-25 illustrate, respectively, alternative-processing concepts for providing the LGA interposer arrays in accordance with various of the embodiments described hereinabove.
DETAILED DESCRIPTION OF THE INVENTION
In the detailed description of the various embodiments, elements or components, which are substantially similar or identical, are designated with the same reference numerals.
Referring to the embodiment of the metal-on-elastomer LGA interposer array 10 , as illustrated in FIG. 1 of the drawings, there are shown a plurality of the interposers 12 in the form of hemi-toroidally shaped elements or so called buttons (generally simulating the shape of a transversely sliced donut). Each of the LGA interposer buttons 12 includes a plurality of circumferentially spaced flexible strip-like metal elements 14 forming electrical contacts which reach from the topmost surface 16 of each respective LGA button 12 to the via 18 which extends through an insulating carrier pad 20 on which the LGA interposer buttons are mounted, and down through the center of the LGA buttons so as to connect to a conductive pad 22 which surrounds through the through via on both sides of the carrier 20 , and extends out along the insulating carrier surface beneath the LGA so as to make electrical contact at the other side or the lowermost end surface 24 of the inversely positioned lower LGA interposer buttons 26 . The electrically-conductive flexible metal elements are primarily strips 14 which extend from the uppermost end of the respective upper LGA interposer buttons 12 inwardly into an essentially cup shaped portion extending to the hole or via 18 formed in the pad 22 .
Consequently, by means of the pads 22 , which are constituted of electrically conductive material or metal and which surround each of the through vias 18 formed in the dielectric material insulating carrier plane 20 , these contact the ends of each of the metal strips 14 , which extend along the external elastomeric material surface of each respective LGA hemi-toroidally shaped interposer structure or button 12 . Accordingly, electrical contact is made from the uppermost or top end of each respective LGA interposer button to the lowermost end 24 of each of the opposite sided LGA interposer buttons 26 at the opposite or lower side of the insulating carrier plane 20 .
With regard to the embodiment illustrated in FIG. 2A of the drawings, wherein the electrical elements 30 consisting of the strips positioned on the top surface 16 of the respective LGA interposer buttons 12 extend towards the through via 18 , in this instance, there is no electrically conductive pad present as in FIG. 1 , but rather the metallic or electrically conductive strips 30 forming the flexible metal contacts extend from the uppermost end 16 of the upper LGA interposer buttons 12 down through the via 18 , the insulating carrier plane 20 to the lowermost ends or apices 24 of the lower inverted LGA buttons 26 on the opposite or bottom side of the structure 10 .
In essence, in both embodiments, in FIGS. 1 and 2A , both the upper and lower LGA interposer buttons 12 , 26 are mirror images and are symmetrical relative to each other on opposite sides of the insulating carrier plane 20 . With regard to FIG. 2B of the drawings, this illustrates primarily a perspective representation of the array of the upper LGA interposer buttons 12 positioned on the insulating carrier plane 20 .
Reverting to the embodiment of FIG. 3 of the drawings, in this instance, the flexible metal electrical contacts 34 , which are positioned so as to extend from the upper ends 16 of each of the respective LGA interposer buttons 12 through the via 18 in the insulating carrier plane 20 , as also represented in the cross-sectional view of FIG. 4 , are designed to have the electrical metal contacts forming a plurality of flexible strips 34 , which extend each unitarily from the upper ends 16 to the lower ends 24 of the hemi-torus shaped buttons 12 , 26 from above and below the insulating carrier plane 20 in a mirror-image arrangement. Hereby, the multiple, circumferentially spaced metal electrical contact strips 34 extend from the uppermost point on one side of the insulating plane to the lowermost point on the opposite side so as to form electrical through-connections at both upper and lower ends and, in effect, forming a reversible structure 10 .
As shown in FIG. 5 of the drawings, in that instance, each of the hemi-toroidally shaped interposer buttons 12 , 26 , which are essentially identical in construction with those shown in FIGS. 3 and 4 of the drawings, have the metal contacts 40 formed so that they extend in a common annular conductive sleeve structure 42 prior to continuing through the via 18 , which is formed in the insulating carrier plane 20 to the upper and lower ends 16 , 26 of the LGA interposer buttons 24 . In FIG. 6 of the drawings, these contacts 40 separate only into separated strip-like portions 42 at the extreme uppermost and lowermost ends of the LGA interposer buttons 12 , 26 and then join together into the essentially annular structure 44 extending through the via 18 formed in the insulating carrier plane 20 .
Referring to the embodiment of FIGS. 7 and 8 of the drawings, these illustrate essentially a structure 50 wherein LGA interposer buttons 12 are arranged only on the upper surface 52 of the insulating carrier plane 20 in a manner similar to FIG. 1 of the drawings, and wherein the conductive strips 14 contact metallic or electrically-conductive pads 54 extending respectively through each of the through vias 18 formed in the insulating carrier plane 20 . The lower surface of each metal pad 54 , in turn, may have a solder ball 56 attached thereto in preparation for a subsequent joining, as is known in the technology.
As shown in the perspective representation of FIG. 9 of the drawings, in that instance, the LGA interposer array structure 60 , which is mounted on the insulating carrier plane 20 , is similar to that shown in FIGS. 7 and 8 of the drawings; however, a slit 62 is formed in the elastomeric material of each LGA interposer button 12 , communicating with the interior 64 thereof, and with the through via 18 , which is formed in the insulating carrier plane 20 , so as to enable any gasses or pressure generated to vent from the interior thereof to the surroundings.
FIG. 10 of the drawings is also similar to the structure shown in FIG. 7 , however, in this instance, each elastomeric interposer button 12 has a plurality of slits 62 or discontinuities formed in the annular toroidally-shaped walls thereof, preferably intermediate respective flexible metal strips 14 , which are located on the upper and inward downwardly extending surface of each elastomer buttons, so as to enable each separate segment 68 to be able to resiliently or flexibly respond to changes or irregularities in the topography of elements contacting the LGA interposer buttons 12 . Also, each segment 68 between each of respective metal contact strips 14 may respond mechanically or independently, so as not to only accommodate differences in topography with a mating surface or differences in the shape of mating solder balls, but in cases where a solder ball will be pressed against the toroidal contacts to produce an electrical connection. In effect, this will enable a mechanical or physical compensation for encountered differences in contact surfaces.
With regard to the embodiment of FIG. 11 of the drawings, which is somewhat similar to FIG. 10 , in that instance, at least one or more of the segments 68 , which are separated by the intermediate slits extending through the LGA interposer buttons are different in height, so as to have some of the segments 70 higher than others in a z- or vertical direction relative to the plane of the insulating carrier plane 20 . In this instance, two segments 68 of the four independent segments of each respective LGA interposer button 12 are shown to be lower in height than the other segments 70 .
With regard to FIG. 12 of the drawings, in this instance, the array structure 74 of the hemi-toroidal LGA interposer buttons 76 , which are mounted on the insulating carrier plane 20 , the opposite or lower side 78 of which has solder balls 80 connected to electrically-conductive pads 82 extending through the vias 18 , has the centers 84 of the respective LGA interposer buttons 76 , which have electrical strip-like contacts 88 extending downwardly, as shown in FIG. 13 , have a contoured inner wall configuration 90 , which allows for nesting or a snap-fit with a solder ball (not shown), which may be brought into engagement therewith. In this instance, FIG. 13 showing the cross-sectional representation of FIG. 12 , illustrates the knob-shaped interior sidewall profile 90 of the compliant interposer button with the separate metal contact strips 88 extending upwardly along the interior of wall 90 to the topmost end 92 of each respective LGA interposer button 76 .
As illustrated in the embodiment of FIG. 14 of the drawings, in this instance, as also shown in cross-section in FIG. 15 ; multiple metal strip contacts 88 extend from the top surfaces of the compliant LGA button structure 100 , passing over the top surfaces 102 and extending down into the center part of the hole 104 provided in each interposer button 106 , and meeting with a common pad-shaped metal conductor 108 , which extends along the upper surface 110 of the insulating carrier plane 20 under the button in contact with strips 88 and outwardly until reaching a via 112 , which extends the metal pad downwardly through the insulating carrier plane 20 and along the lower surface 114 thereof, so as to contact solder balls 116 . This is illustrated in the cross-sectional representation of FIG. 15 of the drawings, which also shows a filled injection tube 120 extending through the insulating carrier plane 20 and a residue break off point 122 , where an elastomer portion was separated from an injection port on a mold forming the entire LGA button structure. This embodiment, showing the filled injection tube for the plastic material, is adapted for the method in which the injection molding of elastomeric material is implemented from the bottom side of the insulating carrier plane 20 .
As shown in FIG. 16 of the drawings, which is essentially similar to the embodiment of FIG. 15 , in that instance, this illustrates a filler injection tube, the mold (not shown) forming the LGA button structure is implemented by injection molding from the top side of the mold, and a residual mass of elastomer 132 can be ascertained extending from the side 134 of the elastic LGA button structure 100 from which it was separated at the injection port of a mold.
Also indicated in FIG. 16 are two types of anchoring holes in the insulating carrier plane 20 , wherein one hole 136 extends all the way through to the other side thereof, and wherein a blob 138 of residual excess molding material penetrates slightly beyond the bottom surface of the insulating carrier plane 20 . Another type of anchoring hole or cavity 140 does not extend fully through the insulating carrier plane 20 , but is formed as a depression in the top surface of the latter, so as to mechanically anchor the elastomeric material of each LGA interposer button to the structure or plane 20 .
Reverting to the embodiment of FIGS. 17 and 18 of the drawings, these show another aspect of providing an LGA interposer array 150 on an insulating carrier plane 20 , wherein a multiple of LGA interposer buttons 152 of essentially conical configurations and their electrical metallic strip contacts 154 , which extend over the topmost ends 156 thereof, service a common I/O electrical contact 158 in the form of a pad on the upper surface of plane 20 . In this instance, the structure incorporates an electrically conductive via 160 extending through the insulating carrier plane 20 , shown in a center of a group of four LGA interposer buttons 102 , as a common meeting point of the metal contact strips 154 on pad 158 , which extend from respectively one each of the top of each LGA button down the side thereof and into the via metallurgy of the structure, towards the bottom of plane 20 , as shown in cross-section in FIG. 18 of the drawings.
Reverting to the embodiment of FIGS. 19 and 20 of the drawings, which is quite similar to the embodiment of FIGS. 17 and 18 , in that instance, the primary distinction resides in that at least one or two of the LGA interposer buttons 152 of a respective group thereof has or have a height which differs from the remaining interposer buttons of that group. For example, two or more buttons 152 of each group may be taller than the remaining buttons 164 of that group (of four buttons) in order to essentially create a lateral stop mechanism for a side loading of a module, through such groupings of LGA interposer buttons in respective arrays. In essence, the different heights in the LGA interposer button groups enable a module with an associated solder ball to be brought into contact and aligned by means of lateral insertion, rather than only vertical insertion, wherein the higher LGA interposer buttons provide stops for the solder balls in order to register with the essentially hemi-toroidally shaped elastomeric contacts.
Reverting to the embodiment of FIGS. 21 and 22 of the drawings, in this instance, there is provided an LGA interposer array 170 arranged on an insulating carrier plane 20 , wherein multiple points of contact for each I/O are provided by means of linear bars of elastomeric LGA interposers 172 . This provides a compliant structure on which a plurality of spaced metallic electrical contact strip elements 174 may be positioned so as to extend from the top 176 of each respective interposer bar 172 both above and below the insulating carrier plane 20 , as shown in FIG. 22 , into electrically sleeve-like conductive vias 178 formed extending through the insulating carrier plane 20 in contact with respective metal strip contacts 180 above and below the insulating carrier plane 20 . In that instance, the metal contact strips 180 may be formed with different shapes, such as one typical contact joining from two separate ships 182 into a single common strip 184 near the top, as clearly illustrated in FIG. 21 , or joining further down near the via extending through the carrier plane to the other side. Furthermore, three or more contact points for each I/O may be provided and different types of contact elements may be utilized along the bar whereby some types may be more suitable for conduction of signals and others for high amperage power feeds.
As illustrated in FIGS. 23-25 , there are shown alternate process flows for a balled module, wherein a balled module zoo, as shown in FIG. 23 , can be directed either towards a solder reflow line for normal BGA connection to a PWB, as illustrated in FIG. 24 , or alternatively, to an LGA interposer assembly 210 where it is assembled by means of a hemi-toroidal LGA and PWB (wiring board) under pressure to make a field replaceable unit, as shown in FIG. 25 of the drawings.
With regard to the configurations of the LGA interposer buttons, these may be of elastic structural members, which are conical, dome-shaped conic sections or other positive release shapes, such as roughly cylindrical or hemispherical, hemi-toroids, and wherein the metal coating forming the electrically conductive contact members or strips terminate at the apices of each of the multiple buttons.
Moreover, the elastomeric material, which is utilized for each of the LGA interposer buttons or for the linear shaped elastic structural member (as shown in FIGS. 21 and 22 ) may be constituted of any suitable molded polymer from any rubber-like moldable composition, which, for example, among others, may consist of silicon rubber, also known as siloxane or PDMS, polyurethane, polybutadiene and its copolymers, polystyrene and its copolymers, acrylonitrile and its copolymers and epoxides and its copolymers.
The connectors of the inventive LGA structure may be injection molded or transfer molded onto an insulating carrier plane 20 , and may serve the purpose of mechanically anchoring the contact to the insulating carrier plane and in instances can provide a conduit for the electrical connections which pass from the top surface of the connector to the bottom surface thereof.
In addition to connecting chip modules to printed circuit boards, the arrays of the LGA interposer buttons or linear structure may be employed for chip-to-chip connection in chip stacking or for board to board connections, the contacts may be of any shape and produced by injecting the elastomer in the same side as where the elastomer contact will be anchored to the insulating carrier by a hole or holes or vias, which extend through the insulating carrier or by any cavity edge formed into the surface of the insulating carrier.
In essence, the molding of the elastomeric material component or components, such as the hemi-toroidal interposer or interposers may be implemented in that the elastomeric polymer material is ejected from the same side at which the interposer will be positioned on the insulating carrier plane, and will be anchored to the insulating carrier plane by means of a hole or holes, as illustrated in the drawings, which either extend completely through to the opposite side of the insulating carrier plane, or through the intermediary of a cavity which is etched or formed into the surface of the insulating carrier plane, which does not extend all the way through the thickness thereof, and wherein any cavity may have flared undercut sidewalls from maximum anchoring ability or by simple surface roughening of the insulating carrier plane. This is clearly illustrated in the embodiments represented in FIGS. 15 and 16 of the drawings.
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the scope and spirit of the present invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims. | A method of operatively combining a plurality of components to form a land grid array (LGA) interposer structure, including an electrically insulating carrier plane, and at least one interposer mounted on a first surface of said carrier plane. The interposer possesses a hemi-toroidal configuration in transverse cross-section and is constituted of a dielectric elastomeric material. A plurality of electrically-conductive elements are arranged about the surface of the at least one hemi-toroidal interposer and extend radically inwardly and downwardly from an uppermost end thereof into electrical contact with at least one component located on an opposite side of the electrically insulating carrier plane. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Provisional Application 60/878,951, filed Jan. 5, 2007
FIELD OF THE INVENTION
The present invention relates to archery hunting equipment. More particularly, the invention relates to a broadhead arrow point for an arrow, and a method of manufacturing the same.
BACKGROUND OF THE INVENTION
Typically, a broadhead arrow point, or simply broadhead, is an assembly of blades arranged around a central axial shaft or ferrule for attachment to an arrowshaft to form a complete arrow for use in target archery or hunting. The broadhead may be detachable for replacement in case it becomes dull or damaged.
The broadhead applies a large force to the target upon striking it and so must be as strong as possible within the constraints of mass and aerodynamic shape. Existing design broadheads frequently break upon impact with the target so there is a need for an improved stronger broadhead.
Detachable broadheads can become loose from the arrowshaft, or can become detached from the shaft entirely, leading to erratic flight performance or disintegration in flight, which would render the arrow ineffective or lead to something other than the targeted object being impacted, so there is a need for a more secure attachment between the broadhead and the arrowshaft. Additionally, broadheads comprising multiple parts that are inserted together and held by screws or clamps may become loose or fall in handling or in use and parts may be lost rendering the broadhead useless. Broadheads with moving parts, such as cams and swivels may not operate correctly in field conditions outside in weather and mud. Broadheads with separate removable ferrules, sometimes referred to as modular broadheads, may become loose in handling. So there is a need for a unitary broadhead with minimum or no moving parts.
Broadheads are costly to manufacture, and there is constant market pressure to produce an effective high performance broadhead with reduced manufacturing costs.
There have been many broadhead designs developed over the years, yet there are none previously known that optimally combine strength, reliability, and cost. Prior art designs have had detachable blades, multiple threaded ferrules with caps, two piece ferrules, slotted blades, or other features that added to the expense or detracted from the strength and reliability of the broadhead.
For example, Muller in US Published Patent Application 20050181898 Unitary Broadhead Blade Unit discloses an injection molded modular blade unit with separate ferrule which requires a pair of threaded connections; one between the ferrule and the arrowshaft and another between the blade unit and the ferrule. By requiring the blades to be molded, either as an assembly of blades or separably molded and then fused together, and then mated to the ferrule, the configuration results in a design that has several unnecessary potential points of weakness, since sintered metal typically sacrifices some strength compared to sheet or foil stock.
Similar disadvantages exist in U.S. Pat. No. 6,726,581, also to Muller, which also specifies a separate ferrule, and U.S. Pat. No. 6,290,903 to Grace, Jr et al which specifies a molded blade unit of sintered powder.
Thus there is a need for an improved broadhead. The object of the present invention is to overcome these shortcomings and present a strong, economical, and rugged broadhead.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the invention, a broadhead includes a threaded ferrule portion permanently attached to multiple blades. At the distal end of the broadhead, the blades are permanently attached directly together. At the proximal end of the blades, the blades are permanently attached to the ferrule portion. Between the proximal and distal ends, the blades are further permanently attached to the ferrule portion and to each other.
In the discussion to follow, “ferrule” will refer to the separate ferrule piece part before assembly into the broadhead, and “ferrule portion” will refer to the portion of the broadhead arrowpoint (after assembly) comprising the ferrule.
Preferably, the ferrule portion has a proximal end with a threaded portion to receive the mating portion of the arrowshaft for attachment to the shaft. Typically, an arrowshaft comprises an elongated shaft with fletches or vanes at the proximal end and a threaded distal end attachable to the broadhead. Distally of the threaded portion of the ferrule portion there may be one or more conical or spherical contacting portions to receive the blades for permanent attachment. The conical or spherical portions help transmit the axial load imposed by the blades upon the shaft at target impact. By using a conical or spherical portion, the load is transmitted partially by compression between the blades and ferrule portion resulting in a stronger unit than if the load were transmitted by only shear at the blade to ferrule weld attachment.
Typically, the ferrule portion diameter is selected to a predetermined value at various points along its length to achieve a predetermined design value for mass for the broadhead. Typically, the desired mass is about 100 grams, but other design values may be desirable for different applications.
Preferably in accordance with the invention, each blade is formed of stainless steel, preferably 400 Series stainless steel, which may be heat treated for hardness before or after attachment to the ferrule. Preferably the blades are stamped from 416 or 420 series stainless steel. The edges of the blades are beveled where they are attached together to reduce the gap which may be filled upon attachment. Preferably, the blades are individually heat treated to achieve the desired strength and hardness before attachment to the ferrule.
In the preferred embodiment, there are three blades attached symmetrically at intervals around a threaded ferrule portion. The blades are welded to the ferrule portion and to each other by laser welding techniques which are well known in the art. Preferably the welds would be applied at the distal end, where the three blades join together directly, at the blade proximal end where each blade contacts the ferrule portion, and in a middle zone where the blades contact each other and also contact the ferrule portion. In accordance with the invention, the welding laser energy is applied to both sides of a given blade. Preferably the welds may be done to both sides simultaneously. Preferably the laser welds are a series of spot welds which overlap to create a nearly continuous weld along each weld zone.
In accordance with the invention, the ferrule portion has a threaded proximal portion, a proximal shaft extension portion, a proximal conical or spherical portion, a distal shaft extension portion, and a distal conical or spherical portion. The threaded proximal portion may be male or female threads, but is preferably a male thread and the thread on the arrowshaft is preferably female. The threaded portion of the broadhead is threaded into the mating threaded portion of the arrowshaft with sufficient tightening torque to remain firmly attached in use. The proximal conical or spherical portion may have a planar or annular portion contacting the corresponding distal portion of the arrowshaft.
In an optional embodiment, the proximal conical or spherical portion may have a square or hexagonal feature, or opposed flats to enable engagement with a tool to aid in fixing the broadhead securely to an arrowshaft with reduced chance of injury to the person assembling the broadhead to the arrowshaft while simultaneously allowing increased tightening torque to be applied to the arrowshaft-to-broadhead connection.
In accordance with the method aspects of the invention, the method includes stamping the blades from 400 series stainless steel sheet, fixturing them on a rotatable mandrel with a ferrule, spot welding them with a laser of approximately 1200 nM wavelength with peak power of 3 KW with a pulse duration of 3.3 milliseconds on one side of each blade to form welds of approximately 0.030 inches diameter. Tack welds are applied initially to hold the blade assembly and ferrule together for subsequent handling during welding. The blade unit is rotated to bring the next desired weld area under the working range distance of the laser so that the blade assembly may be similarly tack welded on each blade. The blade unit is then welded with power settings and pulse duration as above with a series of spot welds overlapping by 60 to 70 percent. Then the assembly is rotated on the mandrel one third of a turn (in the case of a three bladed broadhead) and welded again in similar fashion. Then it is rotated a further one third of a turn and welded again. Then in further accordance with the invented method, the welded assembly is removed from the mandrel, heat treated for 1.5 hours at 1800 degrees Fahrenheit in an inert atmosphere comprising Argon to harden them to approximately Rc 56, and stress relieved for 15 minutes at 900 degrees Fahrenheit in an Argon comprising inert atmosphere. Optionally the heat treatment may be in an oxidizing atmosphere to achieve a black oxide finish which would be advantageous in an application requiring camouflaging the user. The blades are sharpened by grinding at an angle of 60 degrees, and then lapped by conventional means, and then the broadhead is cleaned and packaged.
Optionally in addition the distal point of the broadhead may be welded from both sides of each blade simultaneously. In the case of a three bladed broadhead all three blades are welded together at the tip with welds directed from one, two or three directions as will be explained in detail later.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of an arrow with arrowshaft and broadhead.
FIG. 2 is a ferrule used in the invented broadhead.
FIG. 3 is an optionally used ferrule in the invented broadhead.
FIG. 4 is a side view of a ferrule used in the invented broadhead
FIG. 5 is a blade of the invented broadhead.
FIG. 6 is a side view of the invented broadhead
FIG. 7 is a detail of the distal end of the invented broadhead.
FIG. 8A is a schematic representation of the invented welding method.
FIG. 8B shows details of the blade assembly configured prior to welding.
FIG. 8C shows a detail of the preferred blade bevel.
FIG. 9 is a schematic representation of an invented alternate welding method.
FIG. 10 is an end view illustrating the invented method.
FIG. 11 is an end view of the invented broadhead
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, in FIG. 1 the invented broadhead 1 is shown in relation to an arrowshaft 2 . Threads 6 , shown as preferably male in broadhead 1 engage with threads 19 shown as preferably female of arrowshaft 2 to form arrow 20 . Broadhead 1 comprises multiple blades 10 which form a blade assembly 33 which is attached to ferrule 3 . Broadhead 1 comprises cutting edges 36 . Arrowshaft 2 comprises fletches 34 . FIG. 2 more clearly shows ferrule 3 which is conventional and known in the art and is optionally used in the invented broadhead 1 .
FIG. 3 shows an optional ferrule 4 with tightening feature 5 which may optionally be used in the invented broadhead 1 . Tightening feature 5 may be a hexagonal nut feature (as shown) or a pair of opposed flats or similar features that allow a tool to be used to apply a tightening torque encouraging engagement of threads 6 to engage threads 19 in secure assembly of the broadhead 1 to arrowshaft 2 to form arrow 20 .
FIG. 4 shows a side view of optional ferrule 21 which features cone 7 which provides a site for attachments 15 . Threads 6 are shown at proximal end of ferrule 21 . Cone 7 may optionally be replaced by a hemisphere (not shown). Attachments 15 are preferably laser welds as described later. We have found optimized cone angle 20 of proximal cone or sphere 7 to be preferably 30 degrees to 60 degrees, and more preferably 40 degrees to 50 degrees for best strength and flight characteristics of the broadhead. Ferrule 21 also has a shaft distal portion 8 with portion length 22 and diameter 23 which may be adjusted during ferrule fabrication to achieve the target mass for the ferrule 21 . Distal cone or sphere 9 provides a site for welds 16 . Distal cone or sphere 9 may vary from cone or spherical shape. For example a bullet nose or ellipsoid shape may optionally be used.
Various alternative embodiments of the invention may use ferrules 3 , 4 , or 21 . Blade 10 is shown in detail in FIG. 5 . Blade 10 is preferably made of metal, preferably stainless steel, preferably 400 series stainless steel. In the most preferred embodiment, blade 10 is made of 420 Stainless Steel. Blade 10 includes proximal attachment zone 12 , which attached to proximal cone or sphere 7 in the broadhead 1 . Blade 10 also includes intermediate attachment zone 13 and distal attachment zone 14 . Both intermediate attachment zone 13 and distal attachment zone 14 are preferably beveled with bevel 24 to enhance the attachment to the corresponding zones of adjacent blades 10 when assembling multiple blades 10 with ferrule 21 or ferrule 3 to fabricate broadhead 1 . Bevel 24 is preferably formed by coining but can also be formed by machining and results in bevel angle 11 which is preferably about 45 degrees. Bevel 24 is coined with a coining punch (not shown) using techniques well known in the art. Any resulting flash may be trimmed off with a trimming die (not shown.) Blade edge 35 is initially formed dull and will be ground to cutting surface 36 after the blades 10 are welded to ferrule 3 , 4 , or 21 to form broadhead 1 .
As shown in FIG. 6 , blades 10 are attached to ferrule 3 , preferably by laser welding, at attachment zones 15 and 16 , and are attached to each other at attachment zone 17 . Optionally, ferrule 3 or ferrule 4 (not shown) may be used instead of the preferred ferrule 21 . At attachment zone 16 , the blades 10 are preferentially welded to each other as well as to ferrule 3 , ferrule 4 , or ferrule 21 at distal cone or sphere 9 .
FIG. 7 shows a detail of attachment zone 17 . The welds 18 may be spaced at intervals or preferably overlap to form a series of overlapping welds 19 that have minimum or no space between welds. Preferably, the overlap is 60 to 70 percent overlap between adjacent welds.
The same overlap is preferably applied at attachment zones 15 and 16 (detail not shown).
As shown in FIG. 8A , corresponding to the view A-A of FIG. 6 , bevel 24 allows optimal gap 27 between the blades. In the preferred embodiment, details of which are shown in FIG. 8B , gap 27 is about 0.012 inches and weld channel angle 38 is about 30 degrees. Weld channel angle 38 permits radiant energy 28 to be applied simultaneously to gap 27 and along bevel 24 to bevel contact point 39 enhancing the strength of welds 18 , or 19 . These preferred dimensions are achieved when blade 10 is coined with bevel 24 chosen to be about 45 degrees and remaining unbeveled stock depth 37 (shown in FIG. 8C ) is about 0.008 inches. Laser 25 applies radiant energy 28 through fiber optic lines 26 to apply radiant energy 28 to both sides of blades 10 at gap 27 to create a weld 18 (shown in FIG. 7 ) or series of overlapping welds 19 to blades 10 .
Optionally, as shown in FIG. 9 , one or more additional fiber optic lines 26 may be employed to simultaneously apply energy 28 to both sides of blade 10 at once. The simultaneous welding is achieved in a staggered manner to avoid excessive heat buildup. In the preferred embodiment, optional simultaneous welding of both sides of blade 10 would be done at attachment zones 15 , 16 , and 17 by welding attachment zone 15 on one side of blade 10 while the other side of blade 10 would be simultaneously welded at attachment zone 16 . Then while the first side of blade 10 is being welded at attachment zone 16 , the other side would be being welded at attachment zone 17 , and the first side of blade 10 is welded at attachment zone 17 while the opposite side is being welded at attachment zone 15 .
FIG. 10 shows details of the invented method of FIG. 8 whereby the assembly of blades 10 and ferrule 21 (not shown) is mounted on a mandrel (not shown) and then welded along one line of overlapping welds 19 ( FIG. 10 a ) rotated 120 degrees, welded again ( FIG. 10 b ), rotated 120 degrees, and welded ( FIG. 10 c ). An end view of the welded assembly is shown in FIG. 10 d.
FIG. 11 shows another end view of invented broadhead 1 with angle 28 preferably 120 degrees and bevel angle 29 being preferably 30 degrees so that bevel 30 of blade 10 is thereby coplanar with bevel 31 of adjacent blade 10 thus allowing broadhead 1 to be sharpened on a flat honing stone (not shown.)
Broadhead 1 is a modular assembly of blades and ferrule portion which is easier to handle in field (hunting) conditions than a prior art assembly of numerous small easily lost pieces. There are no moving parts to lose. It may be easily sharpened in the field while mounted to the arrowshaft because the three blades are permanently deployed in a 120 degree arrangement so that each blade edge is in a plane with its adjacent blade's edge leading to ease of sharpening with a flat stone. The blades are preferably welded to the ferrule portion on both sides as seen in FIG. 10 . The welded tips 17 provide mutual support resulting in a strengthened impact point 32 as well as cut on contact. Cut on contact is a design feature well known in the art and means ability to cut the target animal's flesh immediately upon impact. The impact strength is further increased by the unitary ferrule portion designed for maximum axial (impact) load support and then further being welded to the blades. The welded assembly is resistant to deformation which could result in asymmetrical flight or wobble. The ferrule portion may be selected from a different species of steel (preferably 416 SST) from that of the blades (preferably 416 or 420 SST) allowing optimum material selection choices for both.
In the method aspects of the invention, as shown in FIG. 10 , the blades 10 are welded by radiant energy 28 applied by laser 25 to create welds 18 or preferably overlapping welds 19 . Initially the welds are tack welds to hold the blades and ferrule in their correct alignment for further welding. FIG. 10 shows the view taken along sightline A-A in FIG. 6 . In the invented method, the welds are created by a series of overlapping spot welds along gap 27 . The fiber optic line 26 is passed along the length of the area to be welded, attachment zones 15 , 16 , and 17 in turn, applying an appropriate amount of laser energy to fuse the blades 10 together in attachment zone 17 or to fuse the blades 10 to the ferrule 3 , 4 , or 21 at attachment zone 15 , or to both blades 10 and ferrule 3 , 4 , or 21 at attachment zone 16 . Typically, a 1200 nM wavelength laser beam with a peak power of 3 KW with a pulse duration of 3.3 milliseconds and focused spot size of 0.025 inches is used to accomplish the laser welding. After all the welds along a series of welds are completed, the broadhead is rotated on the mandrel and the next series is welded as shown in FIG. 10 b and repeated as shown in FIG. 10 c . The resulting weld series results in both sides of each blade being welded to both an adjacent blade and the ferrule.
While various dimensions in the drawings have been specifically shown, it is not intended that these dimensions be limiting in any way since many other dimensions can be used as desired.
While these embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications will be made without departing from the invention in its broader aspects. The aim of the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A chisel-type broadhead comprises a threaded ferrule laser welded to multiple blades. The blades are welded from both sides. The blades are welded to each other and to the ferrule. The ferrule and blades are configured to provide maximum impact strength to the broadhead. An optional feature enabling the broadhead ferrule threads to be tightened to the arrowshaft is provided. An improved method of welding the blades to the ferrule is provided. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional patent application No. 60/843,317, filed Sep. 8, 2006, which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
The present invention relates generally to fluid sampling systems either employing an analyzer selectively coupled to a sample location of a fluid for extracting a fluid sample therefrom, or alternatively for collection of a sample for subsequent analysis by an analyzer at a remote location.
1. Technical Field
Most gas and liquid chemical composition and physical property analyzers need to extract fluid samples, either continuously or intermittently, from the location where the fluid to be tested resides (the “sample location”—Si in the Figures). This sample fluid is then transported to the inside of the analyzer detector to obtain a desired test result or to a storage vessel from which sampling later occurs using another extractive sampling system. For the purposes of this disclosure, either the detector or the storage vessel constitutes a “sample destination”.
2. Description of Prior Art
A variety of extractive sampling systems exist. The simplest consist of a fluid transport tube of varying diameters and lengths with or without an in-line sample pump that moves the fluid from the sample location to the sample destination. Simple fluid sampling systems are reliable and allow accurate fluid properties analysis only if the fluid is very clean, the fluid has physical and chemical properties that do not change during transport in the sampling system, the sampling is not continuous, and no valves or other flow control components are present in the flow path. Most useful sampling system applications require additional components or they will plug in a short time or damage the analyzer or flow control components.
If the fluid contains suspended solid matter, and the solid material either obstructs the flow of the fluid or interferes in some way with the pump, connecting valve, or the analyzer detector, a particle filter is often installed in or near the sample location end of the fluid transport tube. Typical sample fluid transport tube diameters on the sample location side (upstream) of the filter are 0.25 inches or greater and inside diameters are 0.18 inches or greater to increase the time before such particles obstruct the fluid transport tube and reduce sample flow. If the fluid transport tube is easily plugged by particles, a conventional remedy is to increase the cross sectional diameter of the fluid transport tube and the filter. This increase allows more solid matter to accumulate before the sampling system must be cleaned. However, the volume increase this causes slows the transit time of the sample. To compensate for this delay, a higher capacity pumping system is usually added.
Use of conventional diameter sample fluid transport tubing also constrains a sampling system in two other ways. First, if gases or liquids are sampled from furnaces or other hot sources, they must be cooled prior to entry into the analyzer. The more rapidly the fluid is cooled, the less time is involved for reactions to take place that could change the composition of the fluid. For example, when carbon monoxide gas is extracted from an ambient pressure furnace at temperatures higher than approximately 1300 Deg. F., and then is cooled in or by the sampling system to below approximately 700 Deg. F., some of the carbon monoxide reacts with itself to form carbon dioxide and carbon (as soot). The slower the cooling takes place, the greater is the conversion. Because the unit fluid transport tubing wall surface area to internal cross-sectional volume of small diameter is greater than larger diameter fluid transport tubing, fluids in small diameter fluid transport tubes cool more rapidly than those in larger diameter fluid transport tubes. The result is a more accurate chemical analysis of the sample being extracted. Also, quicker cooling deposits less of a material (like soot) that is forms in the fluid transport tube during cooling. Second, assuming a constant fluid sample velocity, smaller diameter fluid transport tubing allows less gas to be removed for analysis. In processes that use or generate small gas volumes (such as research bioprocess reactors or vacuum furnaces, this feature is important.
Regardless of sample fluid transport tube diameter, in cases where large solids or particulates can plug the sample line or the filter in an unacceptably short time, additional components are often added to the sampling system. Most often, these components periodically reverse sample flow or reverse flow (“blow back”) a non-reactive usually inert clean fluid different from the sampled fluid in an attempt to remove accumulated particles from the unfiltered portion of the sample fluid transport tube and the filter itself. When a sample system that uses periodically reversing flow also includes multiple sample locations supplying a single analyzer, a second pump (“purge pump”) is sometimes used to draw fresh sample into fluid transport tubing and filters prior to analysis. This pump adds to the total sample flow through each line and can accelerate sample line plugging.
In many cases, more even more complex sampling systems are employed. When some or all of the fluid can: 1, change phase (if a gas, change into a liquid and if a liquid change into a solid); 2, react in the fluid transport tube to become viscous or form a solid; or 3, if the entrained solid particles are the constituent to be analyzed, the fluid transport tubing can be heated to prevent reactions or condensation or a fluid diluent can be added at or near the sample location. While both these approaches can function with certain fluids, their addition to the sampling system adds considerable complexity and expense to the system cost and they are employed only when necessary.
None of these known fluid sample systems and enhancements can properly handle some types of fluids that are useful to measure. If the fluid contains complex mixtures of chemicals and particles that interact, change phase, are withdrawn from high temperature or high pressure sample location or if complex chemical interactions occur in the sampling system, extractive sampling systems are often unreliable and ineffective. Some examples of such complex mixtures include: combustion gases, especially those produced by burning coal; industrial gas mixtures used for metal refining, processing and treating; certain chemical manufacturing and petroleum refining processes; gases and liquids from bioprocess fermentation and cell culturing; and almost all unfiltered air and wastewater emissions. Useful analytical information that can significantly improve manufacturing processes, reduce energy use and improve environmental compliance is lost when complex fluids affect the sampling system.
As an example, the complex composition of coal combustion gas is known to require several existing extractive sampling system enhancement combinations. Even with the enhancements, they are considered unreliable and are rarely used for continuous analysis.
FIG. 1 presents a diagram of a chemical analyzer with a typical current practice sampling system for measuring the chemical composition of coal combustion products. A typical combination includes: 1, heated sample fluid transport tubing UT 1 -UT 8 , each having a respective length, LUi, or gas dilution (not shown); 2, corresponding sample particle filters FS 1 -FS 8 , associated with each of the inlet sample fluid transport tubing lines, UT 1 -UT 8 , respectively, placed near the sample location to keep the majority of the sample line free from such particles; and 3, periodic gas blow back using clean and dried air or nitrogen to dislodge accumulated sample particles including Fluid 1 Supply 101 , Filter FF 1 106 , and Purge Valves VP 1 . The outlet side of the sample particle filters FSi is coupled to the common gas analyzer 110 through a respective down stream fluid transport tubing DT 1 -DT 8 , each having a respective length, LDi, and a respective series of valves including the Purge Valves VPi, the Sample select valves VSi, and Sample Flow Regulation Valve VFS, 112
For process control, automatic and continuous analyzer operation using corresponding valves, VS 1 -VS 8 , to sequentially select several sample locations is typically desired (also shown in FIG. 1 ). For industrial applications such a system should operate at least six months without servicing or they are considered “unreliable”. However, using current practice sample system enhancements, sample system operation in a coal-fired power plant typically requires weekly service to prevent plugging. Attempts to improve sample system life by increasing the sample line cross-section and the sample flow rate may or may not extend sampling system operating time, however plugging still occurs in much less than 6 months and do to slower cooling, analysis samples from hot locations may become less accurate.
The reduced time before plugging in this and similar applications is caused by at least three properties of the sampled gas. First, the density of solid particles is very high and their size very small which allows them to be effectively entrained in the sample gas. These particles rapidly fill the portion of the sampling system fluid transport tubing LUi upstream of the filter and rapidly accumulate on the filter itself.
Second, coal combustion gas contains a significant portion of condensable chemicals that are in vapor phase in the combustion gas but partially condense even when sample systems are heated to high temperatures or dilution systems are used. The condensables tend to coat the inside diameter of the sample lines upstream of the filter (in combination with the particles present) and progressively decrease the remaining inside diameter reducing sample gas flow. Many of the condensables are very viscous and difficult to remove by blow back.
Third, the condensed liquids and the deposited particles inside the fluid transport tubes chemically react at the points of temperature transition and form a solid cement-like material that adheres to the inside sample fluid transport tube wall and filter. The combination of the condensables' viscosity and there reactions render gas blow back ineffective.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block flow diagram illustration of prior art;
FIG. 2 is a block flow diagram of extractive fluid sampling system in accordance with the present invention; and
FIG. 3 is another block flow diagram of another extractive fluid sampling system in accordance with the present invention embodying the principles of the present presented in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
The novel sampling system in accordance with the present invention provides a remedy for the plugging that occurs in most moderate and severely complex fluids containing a mixture of particles, condensable and complex chemical reactions in a non-obvious, useful and cost-effective manner. In addition, extracted fluid properties undergo less change and more accurately represent the fluid being sampled. When complexity and contamination of the sampled fluids is only moderately severe (such as mixtures of reducing gases, dusts and soot found in heat treating furnaces and headspace of bioprocess reactors), the following two improvements can suffice:
1. Placing the sample filters FS 1 -FS 8 far from the sampling location instead of in close proximity—the ratio of the fluid transport tube lengths LUi/LDi being much greater than 1 whereas in the prior art the ratio is much less than 1.0, and combined with use of specially selected filter media. This non-intuitive approach offers three distinct benefits:
a. An increased percentage of the particulates and condensables are removed by settling or coating the inside of the fluid transport tube before the filter is reached resulting in longer filter life. b. Smaller filter surface area as well as “absolute” filter media, that more effectively removes smaller diameter particles, can be used and still have acceptable filter capacity c. When the fluid contains a mixture of liquids and vapors (gases) of the same chemical compound, filter media can often be selected that minimizes the passage the liquid phase and maximizes of its vapor (if placed near the sampling location, this type of filter would allow vapor to pass through that as it cools further might partially condense downstream of the filter and render reverse flow cleaning methods inoperative)
2. Use of small diameter fluid transport tubing T 1 (0.125″ inside diameter or less) to reduce the likelihood of plugging and use of high flow rate blow back gas. This non-intuitive approach offers seven distinct benefits:
a. The sample transit time is rapid even at low flow rates b. Less mixing of the fluid sample occurs inside the fluid transport tube because smaller diameter flows are less likely to be turbulent and are more likely to approximate theoretical “plug flow” conditions (sharp transitions in fluid properties extracted from the sample location can thus be analyzed). c. Less mixing of fluids in the sample fluid transport tube also results in more effective removal of condensation and solid deposits during reverse flow of a fluid (either the sample fluid or a clean blow back fluid). d. Fluid sample temperature transitions are faster, better maintaining the sample integrity (especially when the fluid transport tubing is connected to a heat conducting fitting attached to an outside furnace or vessel wall or a line cooling system is also used). e. Faster fluid temperature transitions also result in less deposits of sample reaction or condensation products in the form of solids and liquids, and those that occur are nearer the sampling location and not as distributed along the sample fluid transport tube site. f. Chemical reactions and physical deposition that occurs in the sample fluid transport tube even in the absence of temperature effects are also located nearer the sampling location. g. Smaller fluid transport tubing is easier to install, lower cost and uses less fittings than larger diameter fluid transport tubing.
FIG. 2 of the drawings presents a diagram of a chemical analyzer with the improved sampling system of the invention for measuring the chemical composition of heat treating furnace gases, some bioprocesses and other similar moderately contaminated fluids. A preferred embodiment includes a typical sampling system with these improvements and can also include heated sample line fluid transport tubing or gas dilution (both not shown). Typically Fluid 1 consists of elevated pressure clean and dried air or nitrogen that successfully dislodges accumulated sample particles and most condensates in these applications.
When complexity and contamination of the sampled fluids is severe (such as high temperature untreated coal combustion gases and reducing gases found in high temperature powdered metal annealing operations), the additional improvement in combination with the those disclosed in FIG. 2 can suffice.
By referring to FIG. 3 of the drawings, an improvement can be seen by adding a specially designed second fluid supply and control system that dissolves or reacts with deposits in the sample fluid transport tube and on the surface of the filter media. This improvement would generally be activated less frequently than the non-reactive blow back fluid system and has a more complex configuration. Unlike the inert blow back fluid which is passes through the sample line filters in a reverse direction during operation, this second fluid does not pass through the filters. This fluid can flow only as far as the upstream side of the filter media (controlled by the media material itself when liquid or closed upstream valves when a gas or vapor) and preferably is controlled in such a way as to fully coat the upstream (sample location) side of the filter media. Either by supplied Fluid 2 pressure or activating Fluid 1 blow back following a Fluid 2 fill, Fluid 2 flows in a reverse direction from the point of entry through to the sample fluid transport tubing into the sample location. This non-intuitive additional system is composed of four to six components depending on configuration:
h. A fluid supply system that can safely store or supply gas or liquid even if hazardous (Fluid Supply 2 on FIG. 3 )—always included i. A control valve designed to handle either a pressurized supply (such as a supply of de-ionized water or a reactive gas from a pressurized pipe) or can allow a specialized supply pump to force or draw the fluid into the sampling system (VF 2 on FIG. 3 )—always included j. A manifold (or tubing with multiple “tees,” i.e., a 3-port connection) connected to the control valve that leads to each sampling line (identified by numeral 300 in FIG. 3 —one shown)—always included k. Individual check valves (VKi as shown in FIG. 3 ) or solenoid valves (not shown) that connect to the manifold located on individual sample line “tees” in close proximity to and on the sample location side of each sample line filter FSi designed to prevent the dissolving or reacting fluid from being drawn into the sample flow during analysis, minimize residual fluid 2 volume remaining in sample system after completion of it cleaning cycle and prevent Fluid 1 blow back from mixing with Fluid 2 —always included l. The connection “tee” or other junction into each sample line (shown in FIG. 3 but not labeled)—always included m. A specialized supply pump if used (PF 2 on FIG. 3 )—included when Fluid 2 supply pressure is too low n. A pressure or flow switch (SF 2 on FIG. 3 )—included when a means of determining when the proper amount of Fluid 2 has been introduced
The extractive fluid sampling system of the present invention may provide one or more of the following distinct benefits when removing complex sample line contamination:
a. In most cases, Fluid 2 consists of a higher viscosity and density fluid (most often a liquid) than Fluid 1 (most often a gas) can and these properties provide better entraining of particles lodged on the filter media and on the sample tubing walls b. Most condensables can be dissolved by proper selection of Fluid 2 and once dissolved are more easily transported out of the sample system in solution c. Most solids that form from combinations of particles and condensables can also be dissolved by Fluid 2 if properly chosen and also transported out of the sample system in solution or as entrained particles that have less tendency to stick to the tubing or filter media d. When sampling high temperature processes, a liquid can be selected that changes phase and/or suddenly cools the hottest portion of the sample tubing resulting in either an even more effective cleaning of the area where most of the reacted solids form and/or sufficient sudden change in fluid transport tubing temperature that can result in dislodging of non-dissolving or reacting solids because of differential contraction of the sample fluid transport tubing and the solid coating it (thermal shock) e. In those cases where dissolving a solid or a condensing material does not work well, a liquid or gas can be selected that reacts solids in such a way that a more easily removed solid, liquid or gas is formed
FIG. 3 presents a diagram of a chemical analyzer with the additionally improved sampling system for measuring the chemical composition of coal combustion gases, powdered metal annealing furnace gases, and other similar severely contaminated fluids. This system includes the second fluid that is used separately or in conjunction with the blow back fluid to enhance the removal of difficult to remove solids and liquids that form in the sampling fluid transport tubes and on the filter media and walls. While FIG. 3 discloses only one Fluid 2 system, use of additional fluids ( 3 , 4 , 5 , etc.) installed in parallel with the Fluid 2 system are easily added and are desirable in certain situations. A preferred embodiment includes a sampling system with the FIG. 2 and FIG. 3 improvements and can also include heated sample line fluid transport tubing or gas dilution (both not shown).
A preferred embodiment for coal combustion gases would use de-ionized water as Fluid 2 with the possible addition of a vaporizing base mixed in (an example is ammonium hydroxide). This fluid has been shown to dissolve most inorganic acids present in the combustion products as well as most solids that can form a plug the sample fluid transport tubing. This system has successfully operated in a commercial electric power plant for a period in excess of six months. A preferred embodiment for a powdered metal annealing and decarburizing may include de-ionized water as Fluid 2 combined with hydrogen gas periodically added as a Fluid 3 . In this case, addition of Fluid 3 can be in the same manner a Fluid 2 or simultaneously with or as an alternate to Fluid 1 .
It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention. While the present invention has been particularly shown and described with reference to the accompanying figures, it will be understood, however, that other modifications thereto are of course possible, all of which are intended to be within the true spirit and scope of the present invention. It should be appreciated that components of the invention aforedescribed may be substituted for other suitable components for achieving desired results, or that various accessories may be added thereto. | Disclosed is an extractive sampling system to secure representative fluid samples and transport to analyzers as a sample destination. The invention is directed to modification of sample acquisition components and the addition of elements to overcome sample obtainment issues that occur in a variety of fluids to be samples. | 6 |
FIELD OF THE INVENTION
The present teachings relate generally to managing information and, more particularly, to securely managing electronic protected health information (ePHI).
BACKGROUND OF THE INVENTION
A wide variety of medical imaging systems are used for performing diagnostic and surgical procedures in medical treatment rooms. Such systems have been developed to increase a surgeon's ability to perform surgery by providing intra-operative images of anatomical structures within a patient's body. During various types of minimally invasive surgeries like endoscopic, arthroscopic, and laparoscopic procedures, a surgeon is able to visually examine the interior of an organ or joint while conducting the surgery.
Medical imaging systems are known to incorporate various audiovisual devices to allow better monitoring of a medical procedure. These systems allow the surgeon, or other individuals assisting or observing, to utilize the imaging capabilities in different ways, simultaneously or at different times, for a variety of different objectives. One such system is disclosed in U.S. Pat. No. 8,069,420 to Plummer, the content of which is incorporated by reference in its entirety. As discussed therein, both still images and live video are acquired during the surgery and can be output to various different screens or recording devices.
Recent legislation has made the protection of such still images and live video, e.g., electronic protected health information (ePHI), a priority. For example, one piece of legislation is the Health Information Technology for Economic and Clinical Health Act (HITECH Act) of the American Recovery and Reinvestment Act of 2009. One requirement of that legislation is the privacy and security of electronic health information, including the requirement that HIPAA covered entities report certain data breaches. Accordingly, medical professionals are trying to comply with such legislation when using medical imaging systems to create, securely transmit and store ePHI.
In order to comply with privacy and security objectives, current medical imaging systems have implemented security features that prevent accessing any features of an imaging system before a user is authenticated. However, such security features often compromise current workflows and make medical imaging systems less user-friendly. Therefore, it would be beneficial to have a superior system and method for electronic protected health information security for digital medical treatment rooms.
SUMMARY OF THE INVENTION
The needs set forth herein as well as further and other needs and advantages are addressed by the present embodiments, which illustrate solutions and advantages described below.
The system of the present embodiment includes, but is not limited to, a computer in communication with a data store having stored medical imaging data. The computer has a graphical user interface receiving user data from a user, the user data including authentication credentials used to allow the user access to predetermined system resources, an authenticator alternately preventing or allowing the user access to the predetermined system resources by logging the user into the system using the authentication credentials, and a file accessor receiving received medical imaging data and storing the received medical imaging data in the data store, and retrieving the stored medical imaging data from the data store and providing it to the graphical user interface for display to the user. An endoscope provides the received medical imaging data and a touch screen displays the graphical user interface. The medical imaging system may be in an operating room and is adapted to receive and display imaging data from a medical procedure. Documentation data is received from the user through the graphical user interface and is stored in the data store without requiring the user to provide the authentication credentials or be logged into the system, the documentation data concerning information about the medical procedure. The user cannot access the stored medical imaging data before providing the authentication credentials and being logged into the system. The user is logged out of the system after a predetermined amount of time of system inactivity, the predetermined amount of time configurable by the user using the graphical user interface.
In another embodiment the system includes, but is not limited to, a computer in communication with a data store having stored medical imaging data. The computer has a graphical user interface receiving user data from a user, the user data including authentication credentials used to allow the user access to predetermined system resources, an authenticator alternately preventing or allowing the user access to the predetermined system resources by logging the user into the system using the authentication credentials, and a file accessor receiving received medical imaging data and storing the received medical imaging data in the data store, and retrieving the stored medical imaging data from the data store and providing it to the graphical user interface for display to the user. The medical imaging system may be in an operating room and is adapted to receive and display imaging data from a medical procedure. Documentation data may be received from the user through the graphical user interface and is stored in the data store without requiring the user to provide the authentication credentials or be logged into the system, the documentation data concerning information about the medical procedure. The user cannot access the stored medical imaging data before providing the authentication credentials and being logged into the system.
The method of the present embodiment includes the steps, but is not limited to, receiving documentation data from a user through a graphical user interface and storing the documentation data in a data store without requiring the user to provide authentication credentials or be logged into the system, the documentation data concerning information about the medical procedure, retrieving the stored medical imaging data and providing it to the graphical user interface for display to the user only after the user provides the authentication credentials and is logged into the system, and logging the user out of the system after a predetermined amount of time of system inactivity.
Other embodiments of the system and method are described in detail below and are also part of the present teachings.
For a better understanding of the present embodiments, together with other and further aspects thereof, reference is made to the accompanying drawings and detailed description, and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is one embodiment of a medical imaging system according to the present teachings.
FIG. 2 is one embodiment of a flow chart of steps for using the medical imaging system according to FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
The present teachings are described more fully hereinafter with reference to the accompanying drawings, in which the present embodiments are shown. The following description is presented for illustrative purposes only and the present teachings should not be limited to these embodiments. Any computer configuration and architecture satisfying the speed and interface requirements herein described may be suitable for implementing the system and method of the present embodiments.
The assignee of the present application is a provider of medical image capture solutions that manage ePHI (e.g., KARL STORZ®'s OR1 Fusion™, AIDA HD Connect™, AIDA Compact™, etc.). These imaging systems provide a number of benefits. For example, they have central image and data archiving systems that make documentation more convenient and comprehensive, as well as allow editing and marking of image and video files.
Medical imaging systems are used with compatible endoscopic and general surgery devices. For example, they are used in general laparoscopy, nasopharyngoscopy, ear endoscopy, sinuscopy, and plastic surgery wherever a laparoscope/endoscope/arthroscope is indicated for use, although not limited thereto. Users include general surgeons, nurses, and other medical professionals, among others.
Generally, a medical imaging system is a computer-based unit that records, manages, and archives digital images and videos of surgical procedures. It can simplify file management by recording surgical photos and videos to compact digital media, such as CDs, DVDs, Compact Flash Cards, USB Hard Drive, or USB storage devices, which may then be viewed from a personal computer, a DVD player, or from the system itself. The medical imaging system typically records images and videos on a built-in hard drive, where they can be easily accessed after the surgical procedure. The media stored on the hard drive can be tagged with patient-specific information and saved to digital media using a touch screen control panel. This media can also be sent at the push of a button to another computer (such as a server) for long-term storage and browser-based accessibility, although not limited thereto.
In order to comply with recent privacy and security legislation, providers of medical imaging systems have implemented certain security features. For example, known systems require that a user login to the system before performing any task on the system (or worse have no security). However, such features may adversely affect system usability. An imaging system may also log a user out of the system after a predetermined amount of time (e.g., a “timeout” feature). Because systems require a user to be logged into the system (e.g., authenticated) before using it, users of those systems will have to log back in after a timeout occurs.
In use, ePHI may be stored on the medical imaging system in an electronic “filing cabinet.” To access the filing cabinet a user selects the icon through the medical imaging system's graphical user interface (GUI) and a dialog box may ask for a username and password. Once the user enters a valid username and password they may have access to the stored ePHI. After an idle time, the system may automatically log the user out to protect the ePHI.
To address some of the shortcomings with known systems, it is preferable to make the timeout period configurable so the user can set the length of time, as well as whether to enable or disable the timeout feature. When the timeout feature is disabled, the system (and the ePHI) is accessible once a user is logged into the system. In addition, it is preferable that a user can start use of the system (e.g., patient documentation, recording imagery from a procedure, etc.) without first logging into the system. This simplifies a user's workflow by removing the requirement of logging in to begin adding information to the system. To access ePHI stored in the filing cabinet, however, the system may still require input of a username and password in order to comply with security and privacy policies. When nothing is occurring (e.g., no images/videos are being recorded and no one is interacting with the system), the system may log out the current user, thus providing additional protection of patient electronic health information.
As used herein, the term “documentation” generally refers to capturing information about a patient and/or a procedure, although not limited thereto. A patient “case” may first be documented (e.g., created) in the system so that it can be associated with any pictures or video captured during the procedure. The case may be created, accessed, modified, and saved to the system's hard disk or to external media, such as USB drives, CD/DVD, or network servers. Documentation may include providing the following information, although not limited thereto: patient name, patient ID, patient gender, patient birth date, surgeon, referrer, specialty, procedure, procedure date, notes, accession number, facility, station, department, etc. Images and video can then be captured and associated with the patient case
In further embodiments, other authentication features may be incorporated. For example, biometrics (e.g., fingerprint, iris, voice, etc.) and digital signatures may be used, although not limited thereto. However, use of the present teachings with a traditional username/password combination may present an easier, more efficient, and less costly system. The only change for a medical professional may be a process change to enforce log out policies.
Referring now to FIG. 1 , shown is one embodiment of a medical imaging system according to the present teachings. The medical imaging system 100 includes a computer executing software components stored on computer readable media. Imaging data 110 may be provided to the system from a plurality of sources, for example, endoscopes, room cameras, etc. Imaging data may be stored in an ePHI data store 102 accessible by the system.
The medical imaging system 100 also may include a graphical user interface (GUI) 106 that allows a user to interact and control the system with user input 112 , for example, using a touch screen. Users may store user profiles and preferences in a data store 104 . For example, the data store 104 may have username/password information that the authenticator 108 uses to authenticate a user and log them into the system before providing the user access to stored ePHI 102 . Users may also have preferences such as whether a timeout feature is enabled/disabled, and the timeout period after which a user is logged out the system, as determined by a timer 114 .
A file access component 116 (also referred to as “file accessor”) may control access (e.g., saving, retrieving, etc.) to ePHI 102 . Typically, image data for patient cases is automatically saved (e.g., archived) in the data store 102 of the medical imaging system 100 . These cases may be accessible through the GUI 106 by means of a filing cabinet icon or some other identifier. Users may also access various other network locations or removable media (e.g., USB, DVDs, etc.), although not limited thereto. A user may be presented with a list of cases, which may include patent information (e.g., ID, name, etc.) as well as procedure information (e.g., surgeon, procedure name, date/time, etc.). Once a user selects a patient case, the system may play the images/video for the selected case.
Sources of imaging data 110 provided to the system 100 may include any devices, systems, or networks that generate, acquire, store, monitor, or control still images or video. For example, the sources may include image acquisition devices such as endoscopic cameras, video endoscopes, room cameras, light cameras, and boom cameras. Likewise, the sources may include any recording, storage, and/or archival devices or systems, such as traditional video cassette recorders or digital video recording devices (such as a DVD recording device), image capture devices, a PACS (Picture Archiving and Communication System) computer, or a hospital information system. Sources may also include other devices from which medical imaging data may be received, such as a patient monitor or a central computer for controlling various devices, etc.
Once a source of medical imaging data has been selected, the user may then select a particular destination from among the plurality of available destinations to receive the medical imaging data from the presently selected source by pressing a destination icon. In this way, the user may select one, some, or all of the destinations to receive the medical imaging data being supplied from the presently selected source. As each destination icon is pressed, the medical imaging data being supplied by the presently selected source and producing the images presently being viewed in the display window is communicated to the corresponding destination. In addition to selecting and controlling various sources and destinations of medical imaging data, and routing, altering, recording, and viewing that data, the user can also control several other items from the touch screen, such as documentation (e.g., creating patient cases) and image manipulation.
The destinations for the imaging data 110 supplied by the sources may include any devices, systems, or networks that display medical images generated from the medical imaging data, or otherwise communicate the medical imaging data to viewers, or store the imaging data. For example, the destinations may include any of various displays, such as, for example, a flat panel display, a plasma screen, or a computer monitor. Additionally, the destinations may include a recording device or storage device. As described above, ePHI is typically stored in a secure data store 102 accessible by the imaging system 100 .
Referring now to FIG. 2 , shown is one embodiment of a flow chart of steps for using the medical imaging system according to FIG. 1 . As shown, the user may first start using the system 150 without being prompted for login information. This may include beginning documentation on a patient/procedure/etc., or beginning to capture imagery from an imaging source, although not limited thereto. At this point user authentication may not be necessary.
The documentation (or other data) may then be saved 152 in the medical imaging system (e.g., data store 102 shown in FIG. 1 ). When the user then tries to retrieve 154 that data (or other ePHI saved in the system), the system will determine if the user is logged in 156 . If not, the user will be authenticated 158 by getting their username/password combination or some other authentication (e.g., biometrics). Once the user is authenticated they may be provided with stored ePHI 160 . Authenticating the user before allowing the user to retrieve stored ePHI may satisfy security and privacy goals.
With current medical imaging systems, the workflow for using a medical imaging system is as follows:
1. Login 2. Enter patient information 3. Capture images/video 4. Archive (e.g., USB, DVD, network storage, etc.)
Once a user is logged in they can go into the filing cabinet and basically see everything. However, the user may be prevented from other system functionality without first logging in, including the documentation of a new patient/procedure/etc. or beginning to capture new image data, etc. It may be preferable to allow a user to access certain functionality of the system that does not jeopardize the security of stored ePHI.
In accordance with the present teachings, system usability may be increased without decreasing the security of ePHI. Without logging into the system the staff and surgeon can immediately start using the system. For general use of documentation of surgeries in the OR, it may be used by hospitals trying to better enforce greater protection of their patient's electronic health information. When and if they want to review ePHI that is stored in the filing cabinet they can enter a username and password.
Accordingly, with a medical imaging system according to the present teachings the workflow may be as follows:
1. Enter patient information 2. Capture images/video 3. Archive (e.g., USB, DVD, network storage, etc.)
No login may be required to start documentation (or certain other tasks). If a user wants to view procedures in the filing cabinet, however, they may have to login (e.g., login dialog box appears after selecting filing cabinet icon) to comply with security/privacy policies.
In another example, the workflow for a medical imaging system according to the present teachings may be as follows:
1. Enter patient information 2. Capture images/video 3. Archive (e.g., USB, DVD, network storage, etc.). 4. The user leaves the room and the system remains ON. 5. After a pre-determined period of time of inactivity, the system displays a message which reads “Are you finished documenting [Patient Information]? 6. If yes, the case is finalized. If no, the user is able to continue documentation.
In this way, the system keeps two consecutive patient surgeries from accidentally being recorded under the first patient's name.
While the present teachings have been described above in terms of specific embodiments, it is to be understood that they are not limited to these disclosed embodiments. Many modifications and other embodiments will come to mind to those skilled in the art to which this pertains, and which are intended to be and are covered by both this disclosure and the appended claims. It is intended that the scope of the present teachings should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings. | A medical imaging system includes a data store having stored medical imaging data and a computer. The system may be in a medical treatment room and is adapted to receive and display imaging data from a medical procedure. The computer has a graphical user interface that receives authentication credentials. An authenticator alternately prevents or allows a user access by logging the user into the system using the authentication credentials. A file accessor receives received medical imaging data and stores it in the data store, and retrieves the stored medical imaging data and provides it to the graphical user interface for display. Documentation data is received through the graphical user interface and is stored in the data store without requiring the user to provide the authentication credentials or be logged into the system. The user cannot access the stored medical imaging data before providing the authentication credentials and being logged into the system. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 60/191,531, filed Mar. 23, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improved methods and associated apparatus for conversion of agricultural waste to a liquid fuel and, more specifically, it relates to such conversion processes and associated apparatus which will facilitate economical on-site conversion.
2. Description of the Prior Art
Both energy needs and environmental considerations have resulted in many efforts over many decades to provide alternative sources of fuel which would satisfy both objectives. To date, in addition to the conventional fossil fuel sources and the use of nuclear energy, numerous approaches have been taken, including, for example, unique energy sources, such as the wind, or mechanical or thermal use of large bodies of water. Also, with respect to environmental considerations, focus on use of low sulfur coal and/or means for cleaning exhaust from such uses as utilities have been known.
The U.S. Department of Energy is faced with the immense task of balancing energy demand of our society with environmental consequences of generating that energy. The primary focus has been on the efficiency of conversion of fuel to a useful form of energy. Energy can simply be defined as the ability to do work. The energy value of a fuel normally is measured by temperature change and fundamentally fuels are valued by their ability to supply heat. In the traditional sense, some combustion process produces heat from the fuel. As fuel is oxidized, heat is released. The heat is converted through some mechanical means to a more useful form for application to society. The greater the efficiency of that conversion the more energy efficient we become and the less impact on the environment.
It has been suggested to convert agricultural and biological waste such as sawdust and various manures to liquid fuels and subsequently to energy (see Stiller et al., Fuel Processing Technology 49, 167, 1996 and Dadyburjor et al., Paper presented at 209 th National Meeting, American Chemical Society , Anaheim, Calif., April, 1995). The project investigated the effects of recycling “waste” materials by using them as co-liquefaction agents for the conversion of coal to liquid fuels has been considered. See, for example the used shredded tires (see Sharma et al., Energy and Fuels 12, 589, 1998), plastic materials, such as polyvinyl chloride, (see Zondlo, J. W., Paper presented at 214 th National Meeting, American Chemical Society , Las Vegas, Nev., September, 1997) and high density polyethylene, (see Dadyburjor, D. B., Paper presented at the Tri - State Catalysis Society Spring Symposium , Charleston, W.Va., April, 1998), as well as the ag- and bio-wastes.
In an effort to improve the coal liquefaction process, it was hypothesized that organics with conjugated double bonds that are plentiful in manures and other agricultural wastes would catalyze coal liquefaction reactions. In testing the hypothesis, it was found that the wastes did not improve the conversion of coal to liquid fuel, but the organic matter of the wastes were converted completely to fuel.
Coal is not a necessary prerequisite for fuel production from manures. Stiller et al., Co - processing of Agricultural and Biomass Waste With Coal, Fuel Processing Technology , In Press, 1996 indicates that one can produce fuel with good yields using the manure alone, along with an iron-based catalyst, and then the manure can be done almost independent of the manure source.
The present invention focuses on the use of agricultural waste, such as animal manure, for example, as a source of material from which to produce liquid fuel. (See, Stiller et al., Fuel Processing Technology 49, 167, 1996.)
SUMMARY OF THE INVENTION
The present invention provides a method of making a liquid fuel from an agricultural waste which may be animal manure or other materials. It involves mixing of the agricultural waste with a predetermined quantity of a source of hydrogen for hydrogenation and may be hydrogen gas, or water, or both. The mixture is heated to a preferred temperature of about 300° to 400° C. for about 15 to 90 minutes at a desired pressure followed by cooling and removing gas, followed by removing of the liquid fuel from the reactor. The water, if employed, is preferably mixed with the agricultural waste in an amount of at least 50 percent by weight supercritical water to the weight of the agricultural waste.
A catalyst may be employed to enhance the efficiency of the process. In a preferred form, the agricultural waste may be dry before introducing it into the reactor. The water preferably is at about supercritical temperature and serves as both a solvent and a hydrogen donor for the agricultural waste.
Ash, which may be employed as a fertilizer, may be a byproduct of the process.
The apparatus may include a hydrogenating gas source and/or a water source, an agricultural waste source and a pressurizer vessel for providing a pressurized environment for the mixture of agricultural waste and gas and/or water. A reactor containing the mixture is subjected to elevated pressure and heated to a desired temperature for a predetermined period of time after which a cooler serves to cool the mixture and the separator serves to separate it into gas and other components.
It is an object of the present invention to provide a method and associated apparatus for conversion of agricultural waste into a usable liquid fuel product.
It is a further object of the present invention to provide such a system which may employ animal manure as the agricultural waste.
It is another object of the present invention to provide such a system which may economically be performed on a farm thereby eliminating the need to transport the agricultural waste great distances to a processing facility.
It is a further object of the present invention to provide such a fuel while minimizing otherwise present environmental hazards and eliminating undesirable manure odors.
It is a further object of the present invention to provide a system for creating liquid fuel from animal manure which will greatly enhance the energy value of the original manure.
It is a further object of the present invention to provide such a system which will facilitate generation on a farm of fuel for use on the farm for purposes such as generation of electricity or, in the alternative, if desired, for the fuel to be transported to the central refinery unit for conversion into petroleum-like fuels.
It is yet another object of the invention to convert the biomass mixture of agricultural waste and hydrogen gas or water (preferably at about supercritical temperature or both) in such a fashion that the water contained in the biomass would serve as a hydrogen donor for hydrogenating the biomass carbon in order to dehydrate the fuel.
It is yet another object of the present invention to provide such a system which produces an ash byproduct which is suitable for use as a fertilizer.
These and other objects of the invention will be more fully understood from the following description of the invention with reference to the drawings appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the effect of temperature on yield and heating value of a liquid fuel product produced from a reaction performed at 100 psi.
FIGS. 2 and 3 are schematic illustrations of alternate forms of apparatus usable in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As employed herein, a reference to weight percent, unless otherwise expressly stated in a specific context, shall refer to weight percent of a particular constituent as a percentage of a dried or dehydrated agricultural waste material or animal manure material.
As employed herein, the term “animal manure” shall mean non-human fecal matter from animals of the type that may be raised on a farm or in a zoo and shall expressly include, but not be limited to, hog manure, cattle manure and poultry litter.
As employed herein, the term “agricultural waste” shall expressly include, but not be limited to, animal manure, sewage, sludge, human waste, crop residues, sawdust, corn stover, soybean stover, and straw.
As employed herein, the terms “supercritical water” or “water at about supercritical temperature” shall refer to water at or above supercritical temperature and water within several degrees of, but below supercritical temperature.
The present invention employs animal manure as a substrate for catalytic liquefaction, i.e., can be converted to fuel suitable for use in diesel engines with the use of a low-cost (disposable) catalyst. This conversion will eliminate objectionable manure odors, retain the original fertilizer value in a form that can be economically transported, if necessary, and provide adequate fuel to provide electricity for the farm.
Manure is a byproduct of hog production that is both an asset and a liability. The asset is its value as a fertilizer. The liabilities are the odor and the water pollution problems. Converting the manure into fuel will eliminate the problems. The fertilizer value will be retained in the residue and vapors of the conversion process. In concentrated production facilities, disposal will be eliminated. The surplus fuel and fertilizer produced can be marketed profitably.
It has been suggested to convert coal to liquid fuels, using a low-cost, iron-based catalyst (Dadyburjor et al., Use of an Aerosol Technique to Prepare Iron - Sulfide - Based Catalysts for Direct Coal Liquefaction, Chapter 19 in Advanced Catalysts and Nanostructured Materials: Modern Synthetic Methods , W. R. Moser, editor, Academic Press , New York, 1996), and also in the catalytic co-liquefaction of coal with waste materials (Liu et al., Coal/Tire Co - liquefaction Using an Iron - Sulfide Catalyst Impregnated In - situ in the Coal Energy and Fuels 9(4), 673, 1996). The catalyst is obtained by the controlled disproportionation of ferric sulfide to form a pyretic structure and a nonstoichiometric pyrrhotitic structure in intimate contact. Runs by an independent federal laboratory (Stohl et al., Evaluation of West Virginia University's Iron Catalyst Impregnated on Coal, Proc. Coal Liquefaction and Gas Conversion Contractors Review Conference, USDOEE , Pittsburgh, Pa., p.679, 1996) have verified that this catalyst is the most effective of the iron-based catalysts among those funded by the US Department of Energy. Preliminary studies (Stiller et al., Co - processing of Agricultural and Biomass Waste With Coal, Fuel Processing Technology , In Press, 1996) indicate that it is possible to co-liquefy biomass as well as various types of agricultural manures along with coal and this catalyst to form a fuel.
The poultry industry generates huge quantities of litter annually. Currently, some of the poultry litter is used as a fertilizer, and another portion is used as a constituent of feed provided to beef cows. However, there is not enough farm land area in the region to use all the litter as fertilizer. Alternative methods of disposal of agricultural wastes are needed. The present invention uses poultry litter and other agricultural wastes as feedstock for liquefaction. Historically, liquefaction is a process that has been used to convert coal to liquid fuels. Poultry producers would carefully harvest litter for the conversion process. Therefore, storage of litter and the associated loss of litter in runoff would be minimized. Further, legislation is likely to be introduced that could outlaw the use of poultry litter as a feed. Accordingly, improperly managed litter and excess litter could find itself in the waters. Improper management of the litter pollutes the waters with disease-causing bacteria and nutrients which could severely strain water-treatment facilities. Current strategy used to solve this problem is to spread the litter over a wider area. The net effect is that the problem is not solved, but only diluted.
The scope of the problem is well defined. It is imperative to both manage the poultry litter in a non-polluting fashion, and to manage all of the poultry litter. A paradigm shift will be necessary to achieve this. The present invention will not only meet these two requirements, but will also generate energy from the poultry litter. Depending on the relative economics of capital equipment purchases and transport costs for poultry litter, the energy could be generated either at a central station or decentralized to each poultry farm.
As poultry litter in its natural state is a slurry of variable water content, our sample poultry litter will be dried until no moisture is detectable, and then a fixed amount of water will be added. The relative amount of water will be the economically optimum content of water in the feedstock to the commercial reactor. The catalysts used will be relatively cheap materials, and environmentally benign, so that catalyst recovery is not an economic or environmental issue. A preferred catalyst is an iron-sulfide-based disproportionate catalyst. Typical loadings of catalysts are 1-2% by weight of the agricultural waste.
Although poultry litter has value as fertilizer, poultry producers do not own enough land to use all the litter as fertilizer in an environmentally safe manner. Disposal of all litter as fertilizer would require uniform and judicious application to all the land that is tilled and used for pastures in the region (National Agricultural Statistics Service, 1997). As a result, the total amount of poultry litter and wastes from other animals exceeds the amount that can be used as fertilizer.
While other manures can be used as substrates, hog manure is among the preferred for the present invention for the following reasons. Manure from the hog industry is, for the most part, harvestable. Being harvestable is critical for the conversion to fuel, but makes the manure a liability in spite of its value as fertilizer. Storing the manure at a central location and occasional spreading on fields generates odor problems that our society is not willing to tolerate. Thus the hog industry generates manure as a byproduct that desperately needs an alternative use. There are many hog production units, generating adequate quantities of manure to make it cost effective to convert the manure to fuel. Most of these production units also have a use for the fuel, produced, thereby eliminating the need to develop a new marketing system for the fuel to make the process work. For example, corn or soybean stover were also converted to fuel, then a grower-feeder could generate much more fuel than needed on the farm, and a fuel marketing system would almost certainly develop, perhaps similar to milk pickup, after the technology already was on the farm.
While useful, it is more difficult to establish the technology in the cattle industries. Cattle produce much more manure than hogs, but only a small fraction of it is harvestable. Most of the manure that is harvestable is from cattle that are fed purchased feed, resulting in reduced need on-site for the fuel produced. There would, therefore, be greater need for fuel produced by the present invention to be sold. For the fuel to be of any value, it must be sold. Hence, for the cattle industry, the initial fuel marketing is much more important for this process to be of value than it is for the pork industry. With regard to poultry manure, although most is harvestable, it has some of the same drawbacks as cattle manure. Also, poultry manure also has value as a cattle feed.
In the present invention, agricultural waste and, preferably, animal manure is efficiently converted to a fuel with usable byproducts. In a first embodiment of the invention, which will be described herein in connection with FIG. 1 , the source of hydrogen for hydrogenation of the agricultural waste is hydrogen gas which is introduced into the reactor without requiring the addition of water. In a second embodiment of the invention, water, which may be about the temperature of supercritical water or above, may be employed as both a solvent and a hydrogen donor without requiring the use of hydrogen gas. In a third embodiment, both hydrogen gas and water may be employed as hydrogen donors.
Among the important parameters of the product are: the liquid yield (in terms of the dry, ash-free [daf] poultry litter feedstock); and the heat content (BTU/lb liquid product and BTU/lb poultry litter). Some preliminary data are shown in FIG. 1 . Conditions here are relatively mild, except perhaps for the pressure (100 psi hydrogen). Nevertheless, liquid yields are well above 70 weight percent. One pound of poultry litter generated fuel has a heating value of over 22,000 BTU/lb. The dashed lines at the bottom of two of the bar graphs indicate the heating value of one pound of dry poultry litter—approximately 7,000 BTU/lb.
The reaction conditions of the present invention employed to convert the manures to fuel are less rigorous and less expensive then the conditions necessary for liquefaction of coal. The only reactants required are the manures and, in a first embodiment, low pressure hydrogen gas, in a second embodiment, water, and, in a third embodiment, low pressure hydrogen gas and water. The fuel recovered from the reactor in the second embodiment, for example, contained nearly twice the energy value of the original manure (4000 kcal/g vs. 7500 to 7900 kcal/g).
In performing the following experiments, the primary focus was placed on certain reaction conditions. The reaction conditions in question refer to the temperature, pressure, gas composition, reaction time and the amount and type of catalyst, if any, to be used. The parameters found to be the most sensitive to changes, are systematically altered for optimization. These parameters are the temperature, the reaction time and the amount of catalyst. In the second embodiment of the invention, hydrogen gas, which can be rather expensive, is not employed and water is employed as the reactant and hydrogen donor. A statistically designed set of experiments were carried out, where these parameters were systematically varied. In this way, optimal conditions for these parameters can be determined without carrying out runs at all combinations of all the parameters.
All the reactant used was taken from the same sample of hog manure. The sample was sufficiently large that uniform properties can be assured. The properties of interest include the content of water, ash, lignin, cellulose, hemi-cellulose, and energy content. The properties of the sample were characterized prior to the runs. In a typical run, the reactant and catalyst were placed in a high-pressure batch reactor which is then pressurized to the required pressure and composition. The reactor will then be placed in a specially designed vertical agitator to ensure good mixing during reaction and fully immersed in a fluidized sand bath pre-heated to the desired temperature of reaction.
After the reaction time passed, the reactor was removed from the sandbath. The vapor-phase contents of the reactor were quantitatively analyzed by gas chromatography. Major components of the vapor phase included hydrogen sulfide, ammonia and light hydrocarbons like ethane. Finally, the solid and liquid products in the reactor were analyzed by selective dissolution. Currently, solubility in tetrahydrofuran (THF) is used to characterize the overall conversion of the reactant, the oil component of the product is defined as that which is soluble in hexane, while the asphaltene fraction is soluble in tetrahydrofuran but insoluble in hexane.
The present invention provides technology capable of generating liquid-fuel products, and hence energy, from agricultural waste, preferably animal manure. It involves conditions such as temperature, pressure, water content, gas-phase atmosphere and catalyst to obtain optimum parameters for achieving the maximum yield of high-quality liquid fuel. The reactor systems are easily manufactured, may be optimized for different animals and different animal management systems, and can be easily operated on a farm or elsewhere to produce the required fuels.
In one embodiment of the present invention, after the feedstock is loaded into the reactor, the air will be replaced with the gas-phase mixture, which may be hydrogen, at the pressure of interest. The tube reactor may be designed for pressures of the gas as high as 1000 psi at room temperature, though, in the first embodiment, we use values around 100 psi. The reactor will then be clamped to a vibration apparatus and lowered into a fluidized sand bath operated such that the reactor temperature rapidly approaches the reaction temperature, typically around 350° to 400° C.
After the desired time period, generally about 15 to 90 min., the reactor will be raised from the sand bath and removed from the vibration apparatus. The reactor will be cooled to room temperature, after which the gas contents will be removed to an evacuated glass bulb of known volume. Aliquots will be injected into a gas chromatograph, to determine the gas composition quantitatively. The remaining contents of the reactor will then be washed with excess tetrahydrofuran (THF). This dissolves the fuel products, and the weight of the residue after filtration will allow us to determine the conversion of the feedstock. The THF will be removed by a rotary evaporator. The remaining material (the fuel product) will then be analyzed (for lignin and the like) and tested for boiling point and heating value. The fuel product and the non-fuel residue from the reactor may be analyzed. C, H, N, S may be analyzed by any suitable means known to those skilled in the art and the elemental composition of the inorganic fraction may be analyzed by means well known to those skilled in the art, such as spectroscopy, for example.
The presently preferred property ranges of temperatures of about 300 to 400° C.; pressures of about 15 to 150 psia hydrogen gas at room temperature; reaction times of about 15 to 90 min.; atmospheres—nitrogen, helium, and hydrogen; catalysts such as ferric sulfide, multi-metal sulfides; catalyst loading of about 0 to 2 weight percent; and feedstock water content from about 0 to 50 weight percent agricultural waste. In the first embodiment, the water will be at or near zero, and, in another embodiment, water is present along with the hydrogen gas in water amounts of about 50 to 80 weight percent with higher pressure in the reactor. In yet another embodiment, water in an amount of less than 50 weight percent will be used as the primary or sole source of hydrogenation material without the use of hydrogen for this purpose.
Based on these results, farm-scale reactors may be designed and built to accommodate the various wastes.
Water at about supercritical temperature is a preferred reactant in the present invention. Biomass (agricultural waste) in its natural form is an excellent feedstock for the process. Exposing biomass with water to controlled heat and pressure causes water to become a hydrogen donor to the biomass. Oxygen and some CO 2 are released but the majority of the biomass carbon remains as short-chain hydrocarbon. The hydrocarbon material generated has a fuel value of at least about 15,000 BTU/pound of fuel. This is approximately midway between that of coal and diesel fuel. The sulfur content of the hydrocarbon is very low. Most of the sulfur in biomass is present as sulfhydryls and thiols. The sulfur probably is reduced to H 2 S in the process. Likewise, most nitrogen is present in biomass as primary amines. These amines are likely to be reduced to ammonia. Ammonia and H 2 S can be “scrubbed” easily from the effluent gases and returned to the soil as nutrients for plants without an atmospheric phase. The hydrocarbon will be very low in N and S Also, CO 2 released from combustion of the hydrocarbon is not generating additional greenhouse gas to the atmosphere because it originated as CO 2 fixed by photosynthesis, generally within the same year.
Ruminant animal manure, an extreme challenge for other technologies to convert to an effective fuel, is an excellent feedstock for the conversion process of the present invention. The present invention can convert all organic matter of ruminant manure to fuel with a 75% efficiency. Ethanol production from ruminant animal manure is virtually nil and methane generation will recover only about 15% of the original energy in the form of methane with 60-70% of the original substrate unreacted. The present invention would not preclude ethanol or methane generation. There are situations where ethanol or methane is the most desirable form of fuel. The process would be useful to convert the residue of ethanol or methane generation into fuel.
The bulkiness of agricultural waste makes transport inefficient and carrying agricultural waste off the farm increases the potential for exposure to biohazards. The proposed process of the present invention does not contribute to accumulation of greenhouse gases. The CO 2 generated from burning the fuel originated from the atmosphere. If the carbon cycle were to be disrupted, atmospheric CO 2 would be depleted within 20 years to the point where photosynthesis would not be possible.
The lignin portion of the agri-waste has the ideal molecular structure for liquefaction, but traditional liquefaction requires hydrogen investment. The cost for hydrogen limits the potential for traditional liquefaction. The direct liquefaction of agri-waste does not require traditional processes. The present invention has shown that agri-waste can be reacted in supercritical water. In this state, supercritical water acts not only as a solvent, but as a reactant. Portions of organic molecules are driven to react with the supercritical water and produce CO 2 . The hydrogen part of water is then free to react with the cleaved portion of the organic molecule from which the oxidized carbon was released. The oxygen part of the water is used to further oxidize the partially oxidized part of the molecule. The molecule breaks and the fragments are capped with the hydrogen part of the water. Large molecules are reduced in dimension and become hydrogenated as gas is released simultaneously. The major component of the gas is CO 2 .
Referring now to FIG. 2 , there is shown a hopper 2 wherein the agricultural waste is introduced into the apparatus. A suitable conveyor 4 is disposed within conduit 10 . A source of water 12 , which is, preferably, supercritical water, provides a supply of the water to high pressure reservoir 14 from which it is introduced into initial pressurizer 16 wherein the water is admixed with the agricultural waste which is introduced through hopper 2 . The final or second pressurizer 20 receives the admixed agricultural waste and supercritical water through duct 24 . Water dump tanks 30 , 32 serve to receive excess water from the respective pressurizer 16 , 20 . A suitable conveyor 36 transports the water/agricultural waste mix through duct 40 to reactor 42 . In the form shown, the admixed water and agricultural waste which is preferably at a pressure of about 15 to 150 psia is subjected to heating through external electrical heaters 50 , 52 to a temperature of about 300° to 400° C. and is maintained at that temperature for about 15 to 90 minutes. The elevated temperature mix is then passed through cooler 60 in order to reduce the temperature of the mixture to about ambient temperature. In the form shown, a portion of the gas, which results from the reaction, may be withdrawn through valve 64 .
It will be appreciated that the supercritical water serves not only as solvent for the agricultural waste but as a hydrogen donor in effecting hydrogenation of the agricultural waste.
After emerging from the cooler 60 enters separator 70 wherein gas which depending upon the nature of the agricultural waste may include CO 2 and hydrocarbons, water, solids which may include ash suitable for use in fertilizer and the liquid fuel designated oil emerge. Suitable means well known to those skilled in the art for separating the solids from the other materials.
Referring to FIG. 3 , a modified version of the apparatus of the present invention will be considered. A waste in hopper 102 , which receives the agricultural waste which will preferably be animal manure, is introduced into the duct 110 and moved therein by means of conveyor 104 . A water source 112 provides water to high pressure reservoir 114 by means of pump 115 with the reservoir supplying water to the initial pressurizer 116 through pipe 117 and to the final pressurizer 120 through pipe 121 . The agricultural waste and supercritical water are admixed in initial pressurizer 16 and delivered by way of conduit 124 to final pressurizer 120 . Access water is introduced into the second water reservoir 130 through pipes 131 , 133 , if desired. The -pressurized mixture of agricultural waste and supercritical water emerging from final pressurizer 120 is moved under the influence of conveyor 136 into a preheated condenser 137 where the temperature is elevated after which the mixture passes through conduit 140 into reactor 142 with a heater 144 serving to circulate heating water 144 through pipe 145 by pump 146 into reactor 142 and to return water from reactor 142 to heater 144 through pipe 148 . Gas may be withdrawn by valve 150 from the upper end of the reactor and the mixture then passes to cooler 160 which is in heat exchanging relationship to preheater 137 through pipes 162 , 164 . The cooled material, which is cooled to about room temperature, is then delivered to separator 170 for separation of gas and the solids, oil and water which are properly delivered to the desired location. The same pressure temperature and time relationships may be employed in this embodiment as in the embodiment of FIG. 2 . The fuel may be burned in the crude form on the farm to generate electricity.
Shown in dashed lines, designated by reference number 200 in FIGS. 2 and 3 , is the alternate embodiment, wherein block 200 represents a source of hydrogen gas which may be, in one embodiment, used alone as the source of hydrogen in the present process or, in the second embodiment, provided in combination with the water from sources 14 , 114 in practicing another embodiment of the invention.
Reactions were carried out is tubing bombs. A blend of manure (chicken litter, hog manure, dairy manure, sewage sludge) and water was mixed. A sample of the blend was enclosed in a tubing bomb and immersed in a fluidized bed at 400° C. The bomb was shaken to reduce transport limitations. After 30 minutes the bomb was recovered and quenched. An appreciable quantity of gas was generated. The gas composition was primarily CO 2 , but there were also some sulfur containing compounds in the gas stream. The contents of the bomb were emptied and separated by solvent separation as in the normal manner for coal liquefaction. The major component was light oil. The heating value of that oil was measured to be 16,500 BTU/lb of fuel. This experiment was repeated with cow manure and pig manure with similar results. It appeared that about 70% of the weight of the manure was converted to this light oil. A significant quantity of water was consumed by the reaction.
The present invention involves a reaction that converts biomass into an energy-dense fuel. Biomass, such as livestock manure, crop residues, sawdust, and sewage sludge react with supercritical water to generate hydrocarbons, oxygen, and carbon dioxide. The hydrocarbons contain approximately 15,000 BTU/lb compared to approximately 6,000 BTU/lb (dry wt basis) of the biomass feedstock and 18,000 BTU/lb diesel fuel. Not only does the reaction convert biomass to a more energy-dense fuel, it uses the water contained in the biomass as the hydrogen donor for hydrogenating the biomass carbon; in effect dehydrating the fuel. The reaction, therefore, overcomes the two limiting factors of using biomass as a fuel: low energy density and high moisture content.
The technology permits most of the fuel produced from the agricultural waste (biomass) to be converted on-site to electricity.
There are few byproducts from the reaction. The ash component of the feedstock does not react and would be available as a biohazard-free fertilizer. The high-density fuel is low in sulfur and nitrogen. This makes a clean-burning fuel. The sulfur and nitrogen in the feedstock probably are reduced to sulfides and ammonia, respectively, and released in the gas phase. The sulfides could be burned as fuel for the reactor or generator and the gases scrubbed with water to trap the sulfur as sulfates. The sulfates could be used to trap ammonia. The ammonium sulfate could be used as a fertilizer.
Agricultural wastes are continuously available sources of carbon-containing chemicals that are potential fuel precursors. These fuel precursors are generated on farms in the form of litter, manure, straw, stover, etc. These precursors are derived by photosynthesis, which uses atmospheric CO 2 for its substrate. The conversion of these wastes into fuels with the subsequent burning of the fuel, therefore, recycles CO 2 rather than generates it. Inability to convert this waste into environmentally benign materials limits the growth of the agricultural industry in the eastern portion of the United States Newspaper headlines have emphasized the effects of chicken litter on the Chesapeake Bay. North Carolina placed a moratorium on expansion of hog production because of the negative effects of large waste lagoons on the environment.
The objective of the present invention is to produce high-BTU, liquid fuels from agricultural wastes. Poultry litter, dairy manure hog manure, and sewage sludge reacts with supercritical water to produce a high-BTU fuel. The products of this reaction can be divided into three components (1) an oil-like material with a heating value of about 16,000 BTU/lb (2) a char-like material with a heating value of about 12,000 BTU/lb, (3) a gas which is mostly CO 2 . All the ash material is contained in the char or is solubilized in the excess, nonreacted water.
While it is preferred for certain embodiments to employ a suitable catalyst, such use is not essential.
It will be appreciated that the present invention has provided methods and apparatus for convert agricultural waste, such as animal manure, into a usable fuel in an efficient, economical manner. In one embodiment, hydrogen gas is admixed with agricultural waste and processed in accordance with the present invention. In another embodiment, water is admixed with agricultural waste for such processing, and, in a third embodiment, both hydrogen gas and water are admixed with the agricultural waste for such processing. When water is used, it is preferred, but not necessary that it be supercritical water, with the water serving both as a reactant and a source of hydrogen.
Whereas particular embodiments have been described herein for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details may be made without departing from the invention as defined in the appended claims. | A method of making a liquid fuel from agricultural waste which may be animal manure, includes admixing agricultural waste with at least one material selected from the group consisting of hydrogen gas and water, at elevated pressure heating a mixture to about 300° C. to 400° C. for a predetermined time, subsequently cooling the mixture, and subsequently separating gas from liquid. The process produces a liquid fuel having a high heating BTU value per pound of fuel. The water preferably functions as both a solvent and the hydrogen donor for said agricultural waste. Corresponding apparatus is provided. | 8 |
RELATED APPLICATIONS
This application claims priority to provisional application Ser. No. 60/225,409, filed on Aug. 15, 2000.
FIELD OF THE INVENTION
The invention relates to compressors, and more particularly to valve arrangements for controlling the flow of fluid through compressors.
BACKGROUND OF THE INVENTION
It is known to use positive displacement compressors, and more specifically screw compressors, to compress fluids. The rotors or screws of a screw compressor are susceptible to backward rotation when the compressor is stopped because the pressure differential between the discharge side of the compressor and the suction side of the compressor naturally tends to equalize over the rotors. While the compressors can be designed to handle such backward rotation of the rotors, the noise generated by the backward-turning rotors is undesirable.
SUMMARY OF THE INVENTION
To prevent pressure equalization over the compressor, and the resultant backward rotation of the rotors, it is known to use check valves. For the purposes of this description, the compressor is described as being part of a temperature control system, however, it is to be understood that the compressor need not be used in conjunction with a temperature control system. FIG. 1 schematically illustrates a prior art refrigeration system 10 . The system 10 includes a compressor (represented by the dashed box 14 ) having two screws or rotors 16 and a discharge line 18 through which high-pressure refrigerant and lubricating oil exit the rotors 16 at the discharge end of the compressor 14 . The discharge line 18 communicates with an oil separator 22 that separates the oil from the high-pressure refrigerant. The oil returns to an oil sump 26 where it can be reintroduced into the rotors 16 via an oil supply line 30 . The high-pressure refrigerant exits the compressor 14 through the oil separator 22 and travels to a condenser 34 . After exiting the condenser 34 , the condensed refrigerant passes through an expansion valve 38 before reaching an evaporator 42 . From the evaporator 42 , the low-pressure refrigerant returns to the compressor 14 and the refrigeration cycle repeats.
As seen in FIG. 1, a check valve 46 is located at the suction end of the compressor 14 . The check valve 46 prevents high-pressure refrigerant from flowing back through the rotors 16 toward the lower pressure at the suction end of the compressor 14 , and thereby prevents backward rotation of the rotors 16 . An advantage of locating the check valve 46 at the suction end of the compressor 14 is that when the compressor 14 is shut down there is no pressure equalization over the oil system so oil will not be displaced from the oil sump 26 into the rotors 16 . Rather, the pressure is equalized downstream of the discharge end of the compressor 14 .
The disadvantage of locating the check valve 46 as shown in FIG. 1 is that the check valve 46 must be relatively large to prevent the high-pressure gas from taking its natural equalization path over the compressor to the lower-pressure suction end. Additionally, any pressure drop caused by the check valve 46 while the system is operating will substantially reduce the system's capacity.
FIG. 2 shows another prior art refrigeration system 10 ′, with like parts having like reference numerals. In the system 10 ′, a check valve 50 is located downstream of the oil separator 22 . The check valve 50 prevents high-pressure refrigerant from flowing back into the oil separator 22 and the rotors 16 . Locating the check valve 50 downstream of the oil separator 22 also provides advantages. First, the check valve 50 can be relatively small because the high-pressure refrigerant will naturally flow toward the lower-pressure environment of the condenser 34 . In other words, because the high-pressure refrigerant downstream of the oil separator 22 does not tend to flow back into the oil separator 22 , the check valve 50 can be relatively small. Additionally, any pressure drop caused by the check valve 50 while the system is operating will only affect power consumption and not system capacity.
The disadvantage with the location shown in FIG. 2 is that, in most situations, the volume of high-pressure refrigerant in the oil separator 22 is still large enough to cause noticeable backward rotation of the compressor rotors 16 as the pressure equalizes over the compressor 14 . To alleviate this problem, it is known to add a second check valve 54 at the suction end of the compressor 14 . This second check valve 54 operates in the manner described above with respect to the check valve 46 , so that the volume of high-pressure refrigerant in the oil separator 22 does not flow back through the rotors 16 . While this configuration creates maximum isolation of the compressor 14 from the remaining components of the refrigeration system 10 ′, it necessitates the use of two check valves 50 and 54 , and adds to the cost of the refrigeration system 10 ′.
FIG. 3 shows yet another prior art refrigeration system 10 ″, with like parts having like reference numerals. A check valve 58 is located at the discharge end of the compressor 14 , between the rotors 16 and the oil separator 22 . When the compressor 14 stops running, the pressure between the discharge end and the suction end of the compressor 14 equalizes over the oil system via the oil supply line 30 . The disadvantage with this check valve location is that when the pressure is equalized over the oil system, oil from the oil sump 26 is displaced into the rotors 16 , the bearings (not shown), the gears (not shown), and the seal cavities (not shown). Too much oil in the rotors 16 makes the compressor 14 difficult to start and reduces the overall life of the compressor 14 . For example, since oil is not a compressible medium, too much oil in the rotors 16 could create a hydraulic lock situation. To overcome these problems, it has been known to place a solenoid valve 62 in the oil supply line 30 . The solenoid valve 62 is opened when the compressor 14 is running and closed when the compressor 14 is stopped.
One disadvantage with using the solenoid valve 62 is the additional cost. Furthermore, failure of the solenoid valve 62 could cause problems. For example, if the solenoid valve 62 is stuck closed when the compressor 14 is running, the compressor 14 will not get lubrication and will eventually seize. If the solenoid valve 62 is stuck open when the compressor 14 is stopped, oil will be displaced to the rotors 16 , creating the difficult starting conditions that the solenoid valve 62 was intended to prevent.
The present invention provides a valve arrangement that offers many of the advantages discussed above, without most of the disadvantages. More particularly, the invention provides a valve arrangement having a single, relatively small valve located in the discharge line of the compressor. When the compressor is running, the valve provides the necessary fluid communication between the compressor and the oil separator. When the compressor is shut down, the valve blocks fluid communication between the rotors and the oil separator to prevent the high-pressure fluid from flowing back over the rotors.
In addition, the valve arrangement also prevents displacement of oil to the rotors when the compressor shuts down, and does so without the use of a solenoid valve in the oil supply line. To accomplish this, the valve arrangement includes a bleed line communicating between the oil supply line and the discharge line. When the compressor is not operating, the valve and the bleed line provide a pathway for the high and low pressure fluid to equalize over the oil cavities in the compressor while short-circuiting the oil separator and the oil sump. Because the pressure equalization does not occur over the oil sump, substantially no oil is displaced to the rotors.
The valve provides selective communication between the discharge end of the compressor, the oil separator, and the bleed line. A movable member in the valve responds to system pressure so that when the compressor is running, the movable member is in a first position that allows communication between the discharge end of the compressor and the oil separator, while blocking communication between the discharge end of the compressor and the bleed line. When the compressor is stopped, the movable member in the valve moves to a second position that blocks communication between the discharge end of the compressor and the oil separator, and allows communication between the discharge end of the compressor and the bleed line.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 schematically illustrate prior art temperature control systems having various check valve arrangements.
FIG. 4 schematically illustrates a temperature control system embodying the invention, shown in a state where the compressor is running.
FIG. 5 schematically illustrates the temperature control system embodying the invention, shown in a state where the compressor is shut down.
FIG. 6 is a section view of a compressor embodying the invention.
FIG. 7 is a section view of the compressor of FIG. 6, showing the valve arrangement embodying the invention.
FIG. 8 is another section view of the compressor of FIG. 6, showing the oil return line and the bleed line.
FIG. 9 is an enlarged section view, showing the valve in its closed position when the compressor is not running.
FIG. 10 is an enlarged section view, showing the valve in its open position when the compressor is running.
FIG. 11 is an exploded view showing the valve of FIG. 10 .
FIG. 12 is an exploded view of a valve similar to the valve shown in FIG. 11, but without a biasing spring.
FIG. 13 is an exploded view of another valve embodying the invention.
FIG. 14 is an exploded view of yet another valve embodying the invention.
Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 4 and 5 schematically illustrate a temperature control system 100 embodying the invention. The system 100 includes a screw compressor (represented by the dashed box 104 ) having two screws or rotors 108 housed in a compression chamber 112 (shown schematically in FIGS. 4 and 5 ). As mentioned above, the compressor 104 is described as being part of the temperature control system 100 , however, it is to be understood that the compressor need not be used in conjunction with a temperature control system. For example, the compressor 104 could be an air compressor or a compressor used to compress other compressible fluids.
The compressor 104 includes a suction end 116 , where low pressure refrigerant enters the compression chamber 112 , and a discharge end 120 having a discharge line 124 , through which high-pressure refrigerant and lubricating oil (not shown) exit the compression chamber 112 . The discharge line 124 communicates with an oil separator 128 that separates the oil from the high-pressure refrigerant. The oil returns to an oil sump 132 where it can be reintroduced into the compression chamber 112 and to the rotors 108 via an oil supply line 136 .
FIG. 4 illustrates the temperature control system 100 when the compressor 104 is running. The high-pressure refrigerant exits the compressor 104 downstream of the oil separator 128 and travels to a condenser 140 . After exiting the condenser 140 , the condensed refrigerant passes through an expansion valve 144 before reaching an evaporator 148 . From the evaporator 148 , the low-pressure refrigerant returns to the suction end 116 of the compressor 104 and the refrigeration cycle repeats. While the compressor 104 is illustrated as having an integral oil separator 128 and oil sump 132 , it is understood that the oil separator 128 , the oil sump 132 , and the compressor 104 could also be separate units.
In the illustrated embodiment, the compressor 104 also includes a bleed line 152 that communicates with the discharge line 124 and the oil supply line 136 . A valve 156 is coupled to the discharge line 124 to define a portion of the discharge line 124 . The valve 156 is also coupled to the bleed line 152 . The valve 156 is movable from a first position (see FIG. 4 ), wherein the discharge line 124 is open to allow high-pressure refrigerant and lubricating oil to travel into the oil separator 128 when the compressor 104 is running, to a second position (see FIG. 5 ), wherein the discharge line 124 is closed so that high-pressure refrigerant and lubricating oil cannot travel back into the rotors 108 when the compressor 104 is shut down.
In the illustrated embodiment, the valve 156 moves automatically between the first and second positions due to the pressure differential of the refrigerant in the temperature control system 100 . For example, when the compressor 104 is running (FIG. 4 ), the high-pressure refrigerant and lubricating oil exiting the rotors 108 enters the discharge line 124 and travels toward the oil separator 128 . The valve 156 includes a movable member 160 that is moved to the first position by the high-pressure refrigerant and lubricating oil passing through the valve 156 . In the illustrated embodiment, the valve 156 is a reed valve and the movable member 160 is a reed, however, other types of valves can also be used. When the reed 160 is in the first position, the bleed line 152 is closed so that the high-pressure refrigerant and lubricating oil travel through the valve 156 and to the oil separator 128 . Lubricating oil flows through the oil supply line 136 to lubricate the rotors 108 and the other components (not shown) in the compression chamber 112 (i.e., the bearings, the gears, and the shaft seals).
When the compressor 104 is shut down (FIG. 5 ), the reed 160 is moved to the second position by the high-pressure refrigerant and lubricating oil that is trying to pass back through the valve 156 toward the lower pressure at the suction end 116 . As will be described in more detail below, a biasing spring can also be used to move the reed 160 to the second position when the compressor 104 is shut down. When the reed 160 is in the second position, the discharge line 124 is blocked and the bleed line 152 is opened to provide a pathway for the high and low pressure refrigerant to equalize over the oil cavities (not shown in FIGS. 4 and 5) in the compression chamber 112 , while short-circuiting the oil separator 128 and the oil sump 132 . By allowing the pressure to equalize over the bleed line 152 , there is little or no undesirable backward rotation of the rotors 108 . In addition, because the pressure equalization does not occur over the oil sump 132 , substantially no oil is displaced to the rotors 108 .
To ensure that the pressure equalizes over the bleed line 152 and not over the oil supply line 136 , the compressor 104 also includes a restrictor or orifice 164 in the oil supply line 136 . The restrictor 164 functions to increase the pressure drop over the oil supply line 136 . Compared to the oil supply line 136 , the bleed line 152 has a relatively large and unobstructed cross-section, and therefore the bleed line 152 provides the path of least resistance for pressure equalization of the refrigerant.
To further ensure that equalization occurs over the bleed line 152 , the oil sump 132 in the illustrated embodiment is located at a point that is lower than the point where the bleed line 152 connects with the oil supply line 136 , so that the pressure drop over the oil supply line 136 is larger than the pressure drop over the bleed line 152 . As shown in FIGS. 4 and 5, the oil sump 132 is located at a distance h from the point where the bleed line 152 connects with the oil supply line 136 . It should be understood that restrictor 164 and the elevational difference between the oil sump 132 and the bleed line 152 may not be necessary to ensure that the pressure equalizes over the bleed line 152 .
FIGS. 6-10 illustrate the invention as described above embodied in a screw compressor 104 having an integral oil separator 128 and oil sump 132 . Like parts have been given like reference numerals. Referring to FIG. 6, the compressor 104 includes a housing 168 that surrounds the rotors 108 and defines the compression chamber 112 . In FIG. 6, the suction end 116 is on the right side of the compressor 104 and the discharge end 120 is on the left side of the compressor 104 .
The oil separator 128 includes a separator element 172 that circumscribes at least a portion of the discharge end 120 . A discharge outlet 176 defined in the housing 168 provides an exit for the high-pressure refrigerant to leave the compressor 104 after the oil has been separated. The oil sump 132 is shown below the lowest portion of the separator element 172 , and includes an oil filter 180 for filtering the oil returning to the oil sump 132 . Oil separated by the separator element 172 drains into the oil sump 132 through passageway 184 . Oil collected in the oil sump 132 travels back to the rotors 108 via the oil return line 136 . A first portion 136 a of the oil return line 136 is shown in FIG. 6 . Also shown in FIG. 6 is the restrictor or orifice 164 .
FIG. 7 is another section view through the compressor 104 . FIG. 7 illustrates more of the oil return line 136 , again showing the restrictor or orifice 164 , as well as second, third, fourth, and fifth portions 136 b-e , respectively, of the oil return line 136 . Oil cavities or ports 188 are shown in the housing 168 and communicate with the oil return line 136 and the compression chamber 112 to provide lubricating oil to the rotors 108 and to various other components.
FIG. 7 also shows the reed valve 156 positioned in the discharge line 124 of the compressor 104 . The construction of the reed valve 156 will be described in detail below.
FIG. 8 is yet another section view through the compressor 104 . FIG. 8 illustrates how the fifth portion 136 e of the oil return line 136 communicates with the oil ports 188 . Additionally, FIG. 8 shows the bleed line 152 that communicates with the discharge line 124 and the fifth portion 136 e of the oil return line 136 . The bleed line 152 communicates with the discharge line 124 via the reed valve 156 in a manner that will be described in detail below. FIG. 8 also shows the distance h between the point where the bleed line 152 intersects the fifth portion 136 e of the discharge line 136 and the oil level in the oil sump 132 .
FIGS. 9 and 10 are enlarged section views showing the reed valve 156 coupled to the housing 168 inside the compressor 104 . FIG. 11 is an exploded view of the reed valve 156 shown in FIGS. 9 and 10. As seen in FIG. 11, the reed valve 156 includes a first valve portion 192 , a second valve portion 196 , an intermediate valve portion 200 , and the reed 160 , which are all coupled together to form the valve 156 . The first valve portion 192 includes first and second end portions 204 and 208 , respectively, at opposing ends of a body portion 212 . The end portions 204 and 208 are thicker than the body portion 212 so that when the valve 156 is assembled, the reed 160 is retained between the end portions 204 , 208 and is movable toward and away from the body portion 212 . Furthermore, when the valve 156 is assembled, the difference in thickness between the body portion 212 and the end portions 204 , 208 creates opposing slots 214 that communicate with the portion of the discharge line 124 downstream of the valve 156 and the rotors 108 .
The body portion 212 includes an aperture 216 that is sized to communicate with the portion of the discharge line 124 adjacent the discharge end of the rotors 108 . The reed 160 is sized so that when positioned against the body portion 212 , the reed 160 covers the entire aperture 216 . The first and second end portions 204 , 208 each include an aperture 220 for receiving a mounting fastener 224 (see FIGS. 9 and 10 ). In addition to the mounting aperture 220 , the first end portion 204 also includes a bleed line aperture 226 that communicates with the bleed line 152 when the valve 156 is mounted in the compressor 104 . The first end portion 204 also includes a pin spring aperture 228 for receiving a pin spring 232 that helps to hold the valve 156 together before the valve 156 is assembled in the compressor 104 .
The second valve portion 196 has a substantially uniform thickness and includes an elongated aperture 234 that extends between respective first and second surfaces 235 and 236 of the second valve portion 196 . The second valve portion 196 also includes mounting apertures 220 for receiving the mounting fasteners 224 and a pin spring aperture 228 for receiving the pin spring 232 . A recess 240 (shown in phantom in FIG. 11) is formed in the second surface 236 and houses a spring 244 that biases the reed 160 toward the body portion 212 of the first valve portion 192 when the valve 156 is assembled. The spring 244 facilitates movement of the reed 160 to the second position for fast closure under low-pressure-differential stopping conditions. A second, elongated recess 248 (shown in phantom in FIG. 11) is also formed in the second surface 236 . The purpose of the elongated recess 248 will be described below.
The intermediate valve portion 200 is a relatively thin strip of material that is sandwiched between the first and second valve portions 192 and 196 when the valve 156 is assembled. The intermediate valve portion 200 includes mounting apertures 220 for receiving the mounting fasteners 224 and a pin spring aperture 228 for receiving the pin spring 232 . Additionally, the intermediate valve portion 200 includes an elongated aperture 252 and a first bleed line aperture 256 that communicates with a portion of the elongated recess 248 in the second valve portion 196 . The elongated aperture 252 and the first bleed line aperture 256 are positioned such that the reed can completely cover the elongated aperture 252 and the first bleed line aperture 256 when the reed abuts the intermediate valve portion 200 . The intermediate valve portion 200 also includes a second bleed line aperture 260 that communicates with another portion of the elongated recess 248 . In the illustrated embodiment, the second bleed line aperture 260 is positioned below the first bleed line aperture 256 . The second bleed line aperture 260 is substantially aligned with the bleed line aperture 226 in the first valve portion 192 when the valve 156 is assembled.
Referring now to FIG. 9, when the valve 156 is assembled in the compressor 104 and the compressor 104 is shut down, the reed 160 is in the second position (corresponding to the second position shown in FIG. 5) and abuts the body portion 212 , thereby closing the discharge line 124 by covering the aperture 216 that otherwise provides communication to the discharge end of the rotors 108 . As described above, the reed 160 automatically moves to this second position when the compressor 104 is shut down due to the system pressure and/or the biasing spring 244 . As indicated by the arrows in FIG. 9, the high-pressure refrigerant downstream of the rotors 108 and the valve 156 is free to equalize with the lower-pressure refrigerant at the suction end 116 over the pathway defined by the elongated aperture 234 in the second valve portion 196 , the elongated aperture 252 in the intermediate valve member 200 , the first bleed line aperture 256 , the elongated recess 248 , the second bleed line aperture 260 , the bleed line aperture 226 in the first valve portion 192 , and finally, through the bleed line 152 .
Referring now to FIG. 10, when the valve 156 is assembled in the compressor 104 and the compressor 104 is running, the reed 160 is in the first position (corresponding to the first position shown in FIG. 4) and abuts the intermediate valve portion 200 , thereby closing the bleed line 152 by covering the first bleed line aperture 256 in the intermediate valve portion 200 . The discharge line 124 is opened and high-pressure refrigerant and lubricating oil exits the discharge end of the rotors 108 , passes through the elongated aperture 216 in the first valve portion 192 , exits the valve 156 laterally through the opposing slots 214 (only one is shown in FIG. 10 ), and continues through the discharge line 124 in the manner previously described. As described above, the reed 160 automatically moves to this first position when the compressor 104 is running due to the system pressure.
FIG. 12 illustrates an alternative reed valve 156 ′. The reed valve 156 ′ is substantially the same as the reed valve 156 , with like parts having like reference numerals, except that the reed valve 156 ′ does not include the biasing spring 244 and, therefore, does not include the spring recess 240 in the second valve portion 196 . As discussed above, the spring 244 may not be necessary where system pressure is sufficient to automatically operate the valve 156 ′. The components of the spring valve 156 ′ shown in FIG. 12 each also include a second pin spring aperture 228 for receiving a second pin spring 232 .
FIG. 13 illustrates another alternative reed valve 156 ″, with like parts indicated by like reference numerals. The reed valve 156 ″ is different from the reed valves 156 and 156 ′ in that the reed valve 156 ″ does not include an intermediate valve portion 200 . Rather, the reed valve 156 ″ includes a plug 264 that is inserted into the elongated recess 248 in the second valve portion 196 . The plug 264 is inserted into the middle of the elongated recess 248 until substantially flush with the second surface 236 . With the plug 264 in place, the elongated recess 248 forms a U-shaped passageway without the need for the two separate bleed line apertures 156 and 160 in the intermediate valve portion 200 , thereby eliminating the need for the intermediate valve portion 200 .
FIG. 14 shows yet another alternative reed valve 156 ′″, with like parts indicated by like reference numerals and with similar parts indicated by triple-prime (′″) reference numerals . As seen in FIG. 14, the first valve portion 192 ′″ has a substantially uniform thickness while the intermediate valve portion 200 ′″ is thicker and includes first and second end portions 204 ′″ and 208 ′″, respectively, at opposing ends of a body portion 212 ′″. The end portions 204 ′″ and 208 ′″ are thicker than the body portion 212 ′″ so that when the valve 156 ′″ is assembled, the reed 160 is retained between the end portions 204 ′″, 208 ′″ and is movable toward and away from the body portion 212 ′″. Furthermore, when the valve 156 ′″ is assembled, the difference in thickness between the body portion 212 ′″ and the end portions 204 ′″, 208 ′″ creates opposing slots 214 ′″ (only one is shown) that communicate with the portion of the discharge line 124 downstream of the valve 156 ′″ and the rotors 108 .
Instead of the elongated aperture 252 , the intermediate valve portion 200 ′″ includes three separate apertures 252 ′″. Likewise, instead of the elongated aperture 234 , the second valve portion 196 ′″ includes three separate apertures 234 ′″ that are aligned with the apertures 252 ′″ when the valve 156 ′″ is assembled. Changing the elongated apertures 252 and 234 to three separate apertures 252 ′″ and 234 ′″ reduces the available flow area, and may be desirable for certain applications.
While several reed valves 156 - 156 ′″ have been illustrated, other reed valve configurations are also contemplated by the invention. The reed valves can be made from metal or any other suitable materials. It is also understood that various other types of valves could be substituted for the reed valve configurations contemplated.
While the valve arrangement of the invention substantially reduces or eliminates the backward rotation of the rotors, it is possible that a small amount of slow backward rotation may still occur as the pressure equalizes through the oil cavities 188 , which are positioned adjacent the center of the rotors 108 . If desired, this small remaining backward rotation can be eliminated by opening the capacity unloader valves (not shown) that are commonly used in conjunction with screw compressors. Opening the capacity unloader valves reduces the pressure in the compression chamber 112 to the same pressure existing at the suction end 116 , thereby eliminating even the smallest amount of pressure equalization occurring over the rotors 108 .
Various features of the invention are set forth in the following claims. | A compressor and oil separator assembly for compressing a fluid includes a suction end, a discharge end, and first and second rotors rotatably mounted between the suction and discharge ends. A discharge line communicates with the discharge end, and an oil separator communicates with the discharge line. An oil sump communicates with the oil separator and an oil supply line communicates between the oil sump and the rotors. A bleed line selectively communicates between the discharge line and the oil supply line for equalizing a pressure differential between the suction end and the discharge end without causing substantial backward rotation of the rotors or displacement of oil to the rotors through the oil supply line. Preferably, the assembly further includes a valve that defines a portion of the discharge line and is also coupled to the bleed line. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a wireless type tire status monitoring apparatus capable of checking the status of a tire, such as tire air pressure while the driver remains in the vehicle, and a receiver for such a tire status monitoring apparatus. More particularly, this invention relates to a tire status monitoring apparatus and a receiver for the tire status monitoring apparatus which specifies which one of transmitters provided on a plurality of tires is a data sender.
Conventionally, a wireless type tire status monitoring apparatus has been used to enable the driver check the statuses of a plurality of tires provided on a vehicle while the driver remains inside the vehicle passenger compartment. Attached to the tires are respective transmitters which measure the air pressure statuses of the associated tires and transmit data by radio indicative of the measured statuses of the tires. The body of the vehicle is provided with a receiver which receives transmitted data from each transmitter.
Each transmitter sends data indicating the status of the associated tire to a single receiver. The receiver should discriminate from which one of the transmitters on the tires has transmitted the data that was received. Therefore, each transmitter is assigned with an inherent ID code. Each transmitter transmits data indicating the status of the associated tire together with the ID code. Based on the ID code, therefore, the receiver can identify the transmitter which is the sender of the data (see Japanese Patent Laid-Open Publication No. 2000-103209).
To allow the receiver to identify the transmitter which is the sender of data, however, the ID codes of the transmitters in the associated tires provided on the vehicle should be registered in the receiver beforehand. What is more, at the time of initial registration, it is necessary to associate the ID codes with the mounting positions of the tires to which the transmitters having the ID codes are respectively mounted. When new tires are mounted on a vehicle or the mounting positions of the tires with respect to the vehicle are changed, therefore, initial registration should always be performed. Such initial registration involving manual work is difficult and takes time.
SUMMARY OF THE INVENTION
One aspect of the present invention is a receiver for a tire status monitoring apparatus that monitors statuses of a plurality of tires provided on a vehicle. The tire status monitoring apparatus includes a plurality of transmitters, provided on the tires respectively, for transmitting data indicating statuses of the respective tires. The data includes an identification code to identify each tire. The receiver is supplied with an activation signal to activate a drive source of the vehicle. The receiver includes a reception unit which receives the data from the transmitters. A control circuit is connected to the reception unit. Upon detection of the activation signal, the control circuit collates the identification code included in the data and specifies, based on the identification code, each transmitter which has transmitted the data.
Another aspect of the present invention is a tire status monitoring apparatus for monitoring statuses of a plurality of tires provided on a vehicle. The tire status monitoring apparatus includes a plurality of transmitters provided on the tires respectively, which detect statuses of the associated tires and transmit data indicating the detected statuses of the tires. The data includes an identification code to identify each tire. A receiver is provided on the vehicle. The receiver receives the data from the plurality of transmitters and is supplied with an activation signal for activating a drive source of the vehicle. The receiver includes a control circuit. Upon detection of the activation signal, the control circuit collates the identification code included in the data and specifies, based on the identification code, each transmitter which has transmitted the data.
Another aspect of the present invention is a method of monitoring statuses of a plurality of tires provided on a vehicle. The tires include a plurality of transmitters which generate data indicating statuses of the respective tires. The vehicle includes a receiver which receives the data from the transmitters. The data includes an identification code to identify each tire. The method includes detecting an activation signal for activating a drive source of the vehicle, transmitting a request signal for generating the data and transmitting the data to the receiver to the plurality of transmitters, when the activation signal is detected, receiving the data from the plurality of transmitters, collating the identification code included in the data, and specifying each transmitter which has transmitted the data, based on the identification code.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a schematic structural diagram of a tire status monitoring apparatus according to one embodiment of the present invention;
FIG. 2 is a schematic block diagram of a transponder of the tire status monitoring apparatus in FIG. 1 ;
FIG. 3 is a schematic block diagram of a transceiver of the tire status monitoring apparatus in FIG. 1 ; and
FIG. 4 is a flowchart illustrating the operation of the transceiver in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic structural diagram of a vehicle 10 including a tire status monitoring apparatus 1 according to one embodiment of the present invention. As shown in FIG. 1 , the tire status monitoring apparatus 1 includes four transponders (transmitters) 30 provided on respective tires 20 of the vehicle 10 and a single transceiver (receiver for the tire status monitoring apparatus) 40 provided on the body 11 of the vehicle 10 .
Each transponder 30 is fixed inside the associated tire 20 , e.g., on the wheel 21 of the tire 20 . Each transponder 30 measures the status of the associated tire 20 , i.e., air pressure in the associated tire 20 , and transmits transponder data including air pressure data acquired by the measurement. The transponder data is wirelessly transmitted to the transceiver 40 from each transponder 30 .
The transceiver 40 is provided at a predetermined location of the body 11 and operates on power from, for example, the battery (not shown) of the vehicle 10 . The transceiver 40 has four antennae (reception units) 41 respectively corresponding to the four transponders 30 . Each antenna 41 is connected to the transceiver 40 via a cable 42 . The transceiver 40 generates a request signal at a predetermined time interval and transmits the request signal from each antenna 41 . Each transponder 30 generates induced power based on the request signal and transmits transponder data using the induced power. The transceiver 40 receives the transponder data transmitted from each transponder 30 mainly via the associated antenna 41 .
A display 50 is placed in a visible range of the driver of the vehicle 10 , such as in the passenger compartment. The display 50 is connected to the transceiver 40 via a cable 43 . An engine 60 or the drive source of the vehicle 10 is mounted in the front portion of the vehicle 10 .
As shown in FIG. 2 , each transponder 30 includes a controller 31 , a pressure sensor 32 , a transmission/reception circuit 33 and a coil antenna 34 . The controller 31 is, for example, a microcomputer including a CPU (Central Processing Unit), ROM (Read Only Memory) and RAM (Random Access Memory). Inherent ID codes are registered beforehand in the ROM. The ID codes are used to identify the four transponders 30 provided on the vehicle 10 .
The pressure sensor 32 measures the air pressure in the tire 20 and supplies the controller 31 with air pressure data acquired by the measurement. The controller 31 generates transponder data including the air pressure data and the ID code registered in the internal memory, and supplies the transmission/reception circuit 33 with the transponder data.
The transmission/reception circuit 33 encodes and modulates the transponder data, then transmits the encoded and modulated transponder data via the coil antenna 34 . The coil antenna 34 generates induced power based on, for example, the request signal sent from the associated antenna 41 .
The transmission/reception circuit 33 supplies the induced power to the controller 31 . The controller 31 controls the transponder 30 with the supplied induced power. That is, the transponder 30 operates on the power induced in the coil antenna 34 . The controller 31 and the transmission/reception circuit 33 are formed on a single-chip semiconductor substrate and integrated into an IC 35 .
As shown in FIG. 3 , the transceiver 40 includes a controller 44 which processes transponder data received via the antenna 41 and a transmission/reception circuit 45 . The controller 44 is, for example, a microcomputer including a CPU, ROM and RAM. Inherent ID codes are registered in an internal memory, e.g., RAM, of the controller 44 .
The transmission/reception circuit (reception unit) 45 receives the transponder data from each transponder 30 mainly via the associated antenna 41 . The transmission/reception circuit 45 demodulates and decodes the encoded and modulated transponder data, and then supplies the resultant transponder data to the controller 44 .
Based on the received transponder data, the controller 44 determines the air pressure of the tire 20 associated with the sender transponder 30 . The controller 44 displays data about the air pressure on the display 50 . In the case where the air pressure is particularly abnormal, warning of the event is displayed on the display 50 . Further, the controller 44 receives from a key cylinder 80 a signal (activation signal) indicating the ON action of a key switch 70 which activates the drive source of the vehicle 10 , e.g., the engine 60 . In addition, the controller 44 stores an inherent ID code included in transponder data into its own internal memory, e.g., RAM, when a predetermined condition is met. Therefore, an inherent ID code indicating the sender transponder 30 is registered in the internal memory of the controller 44 .
The controller 44 transmits a request signal to the transmission/reception circuit 45 from the antenna 41 at a predetermined time interval. Based on the request signal, induced power is generated in the coil antenna 34 of the transponder 30 . The pressure sensor 32 measures air pressure in the tire 20 using that power. The transponder 30 transmits transponder data including air pressure data via the coil antenna 34 . The transceiver 40 receives the transponder data transmitted from each transponder 30 mainly via the associated antenna 41 .
The operation of the transceiver 40 , specifically, the controller 44 of the transceiver 40 , will be described next referring to the flowchart shown in FIG. 4 .
First, the controller 44 determines if the key switch 70 which activates the engine 60 is turned on by the driver (S 1 ). Specifically, the controller 44 determines if the activation signal from the key cylinder 80 , originated from the ON action of the key switch 70 , has been detected. When it is determined that the key switch 70 has been set to on (YES in S 1 ), the transceiver 40 generates a request signal and sequentially transmits the request signal from the individual antennae 41 (S 2 ). Then, induced power is generated in the coil antenna 34 of the transponder 30 corresponding to each antenna 41 . With the induced power, the pressure sensor 32 of the transponder 30 measures air pressure inside the associated tire. The transponder 30 transmits transponder data including the measured air pressure data via the coil antenna 34 .
The transceiver 40 receives the transponder data, sent from the transponder 30 , via the associated antenna 41 (S 3 ). The controller 44 determines whether the ID code included in the received transponder data (hereinafter called a transponder ID code) matches with an ID code registered in the internal memory of the controller 44 (hereinafter called a registered ID code) (S 4 ). In the case where the transponder ID code matches with the registered ID code (YES in S 4 ), the transceiver 40 terminates the process.
In the case where the transponder ID code does not match with the registered ID code (NO in S 4 ), on the other hand, the controller 44 determines if the transponder data has been received by a first predetermined number of times (e.g., n times) (S 5 ). In the case where the number of receptions of the transponder data has not reached the first predetermined number (NO in S 5 ), the controller 44 returns to the process of step S 2 and transmits the request signal.
In the case where the number of receptions of the transponder data has reached the first predetermined number (YES in S 5 ) and the transponder ID codes received by the first predetermined number of times match with one another a second predetermined number of times or more (e.g., m times where m≦n) (YES in S 6 ), on the other hand, the controller 44 determines that the ID code has been changed. That is, the controller 44 determines that the tire 20 having the transponder 30 has been changed. Specifically, the controller 44 determines that a new tire 20 has been attached to the vehicle 10 . Alternatively, the controller 44 determines that the mounting position of the tire 20 with respect to the vehicle 10 has been changed. The controller 44 stores the changed ID code in the internal memory of the controller 44 . As a result, the changed ID code is newly registered in the internal memory of the controller 44 (S 7 ).
In the case where the transponder ID codes do not match with one another the second predetermined number of times or more in step S 6 , on the other hand, the controller 44 executes other processes (S 8 ). One of the other processes possible may be a process which does not change the registered ID code considering that the transponder ID code has not been changed. In this case, the registered ID code is not changed and the ID code registered at that time remains as it is until the key switch 70 is set to on once again.
The transceiver 40 of the tire status monitoring apparatus 1 according to this embodiment has the following advantages.
(1) In the case where the key switch 70 of the vehicle 10 is set to on, the transceiver 40 transmits a request signal to the transponders 30 at predetermined time intervals. In response to the request signal, the controller 44 of the transceiver 40 determines whether the transponder ID code sent from the transponder 30 matches with an ID code registered in the controller 44 . In the case where the two ID codes do not match with each other and the transponder ID codes received by the first predetermined number of times match with one another the second predetermined number of times or more, the controller 44 determines that the ID code has been changed. In this case, the controller 44 determines that the tire 20 having the transponder 30 has been changed. The controller 44 stores the changed ID code into the internal memory, e.g., RAM. As a result, the changed ID code is registered in the internal memory of the controller 44 . Based on the ID code, therefore, the sender transponder 30 is specified. Even if the tire 20 has been changed, therefore, it is possible to specify the mounting position of the tire 20 and it is unnecessary to carry out the initial registration work for the ID code.
(2) Only when the key switch 70 of the vehicle 10 is set to on, the controller 44 of the transceiver 40 determines whether an ID code has been changed or not. Therefore, the transceiver 40 can efficiently register the ID code into the internal memory of the controller 44 , e.g., RAM. That is, in the case where the controller 44 receives transponder data from the transponder 30 while the vehicle 10 is stopped or is running, the controller 44 need not make a determination on the ID code nor perform registration again. This can reduce the burden of the controller 44 .
(3) When the transponder ID code matches with a registered ID code, the transceiver 40 terminates the process without overwriting the registered ID code. Even if the ID codes match with each other, therefore, the burden of the controller 44 can be relieved.
(4) The transceiver 40 determines whether the ID code has been changed or not in accordance with the ON signal from the key switch 70 of the vehicle 10 . Therefore, no new signal is needed to determine if the ID code has been changed. That is, the transceiver 40 determines if the ID code has been changed by effectively using the existing activation signal. This can permit the transceiver 40 to be easily attached to the vehicle 10 .
It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.
The above-described embodiment may be adapted to a tire status monitoring apparatus that includes a plurality of transmitters which are provided on the respective tires 20 , have batteries, measure the statuses of the associated tires 20 and transmit data indicating the statuses of the tires 20 acquired in the measurement, and a receiver which receives data from those transmitters. The transceiver 40 may have a single common antenna 41 with respect to the four transponders 30 , or may have two antennae 41 respectively provided at the front portion and rear portion of the vehicle 10 . The drive source may be a hybrid engine comprised of, for example, an engine and a motor, or may be a motor. The transponder 30 may have a temperature sensor which measures the temperature inside the associated tire 20 so that temperature data in the tire 20 is transmitted to the transceiver 40 . The air pressure data may be data specifically indicating the value of the air pressure, or data simply indicating whether the air pressure lies within an allowable range or not. In the case where the transponder ID code does not match with a registered ID code, the controller 44 may determine that the transponder ID code has been changed and the tire 20 associated with the changed transponder ID code has been changed. The vehicle may be a two-wheel bicycle or motorcycle, a multi-wheel bus or tractor, or an industrial vehicle or the like (e.g., a forklift) provided with tires 20 . In case where the transponders 30 are provided on the tires of a tractor, the transceiver 40 and the display 50 are placed on the tractor. The transceiver 40 may be activated in accordance with the ON action of the key switch 70 of the vehicle 10 . In this case, after the key switch 70 is set to on, the transceiver 40 transmits a request signal to the transponders 30 and executes the ID code determining process of the above-described embodiment.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. | A receiver of a tire status monitoring apparatus which can specify tire mounting positions and does not require initial registration work. The tire status monitoring apparatus includes a plurality of transmitters which are provided on the respective tires of a vehicle and transmit data indicating statuses of the respective tires. The data includes an identification code to identify each tire, and the receiver is supplied with an activation signal to activate a drive source of the vehicle. The receiver includes a reception unit which receives the data from the transmitters, and a control circuit which is connected to the reception unit and collates the identification code included in the data upon detection of the activation signal and specifies, based on the identification code, each transmitter which has transmitted the data. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 14/093,091, filed on Nov. 29, 2013, now pending, which is a continuation-in-part of U.S. application Ser. No. 12/954,597, filed on Nov. 24, 2010, issued as U.S. Pat. No. 8,615,832, on Dec. 31, 2013, which is a continuation-in-part of U.S. Ser. No. 12/634,066 filed on Dec. 9, 2009, now abandoned, which claims priority benefits to Chinese Patent Application No. 201020281211.4 filed on Aug. 4, 2010, and to Chinese Patent Application No. 201010244717.2 filed on Aug. 4, 2010, and which is a continuation of U.S. Ser. No. 10/568,245 filed on Feb. 14, 2006, now abandoned, which is a National Stage Application of International Patent Application No. PCT/CN2004/000934, with an international filing date of Aug. 12, 2004, which claims priority benefits to Chinese Patent Application No. 03271456.4, filed Aug. 16, 2003. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P. C., Attn.: Dr. Matthias Scholl Esq., 14781 Memorial Drive, Suite 1319, Houston, Tex. 77079.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a nursing bed, and more particularly to a nursing bed for bedridden patients.
2. Description of the Related Art
Nowadays nursing beds are widely used in hospitals. A typical nursing bed includes a single layer of sheet fabric with mesh openings by interweaving a warp and a weft in a vertical direction. Usually, an interweaving point of the warp and the weft is fastened by a fixed connection. Also usually, a diameter or diagonal length of the mesh opening is more than or equal to a diameter of the warp and the weft and less than 30 times the diameter of the warp and the weft. However, this type of fabric easily hurts the skin of patients and affects air permeability of the skin and overall recovery of the patients.
Furthermore, the warp and the weft generally have a diameter of less than 0.55 mm. Thus, the resulting interweaving point has a small area. Even though the interweaving points are bonded by special adhesives, they are unfirm and prone to detachment.
SUMMARY OF THE INVENTION
In view of the above-described problem, it is one objective of the invention to provide a nursing bed that solves the above-mentioned problems.
To achieve the above objectives, in accordance with one embodiment of the invention, provided is a nursing bed, comprising a net-shaped fabric with a plurality of mesh openings and a bearing frame. The net-shaped fabric comprises a warp and a weft interwoven in a vertical direction; an interweaving point of the warp and the weft is fastened by a fixed connection; the diameter or inscribed circle diameter of the mesh opening is 2-6 times the diameter of the warp and the weft; the ratio of the sum of the areas of the mesh openings with respect to the area of the net-shaped fabric is 35% to 78%; the diameter or inscribed circle diameter of the mesh opening is less than 1.5 mm; the diameter of the warp and the weft is less than 0.55 mm; the thickness of the net-shaped fabric is less than 1.1 mm; at least two edges of the net-shaped fabric are connected to two opposite edges of the bearing frame, respectively, whereby forming a mutual positioning structure; a plurality of warp interwoven strips or weft interwoven strips are disposed on the net-shaped fabric in a direction of either the warp or the weft or in directions of both of the warp and the weft; the width of the interwoven strip is less than 3 mm, and the interwoven strips are uniformly distributed on the net-shaped fabric and in the shape of a pectination or a grid.
In a class of this embodiment, a tensile layer is disposed at the edge (also called cutting line) of the net-shaped fabric.
In a class of this embodiment, the tensile layer contains coating materials coated on the net-shaped fabric, and the materials block or partially block the mesh openings on the net-shaped fabric.
In a class of this embodiment, the tensile layer comprises one of a soft fabric, a film, or a non-woven fabric that is coated and fixed on the net-shaped fabric or on the coating materials coated on the net-shaped fabric.
In a class of this embodiment, multiple fixing edges are disposed on edges or strengthening edges of the net-shaped fabric that are connected to the bearing frame. The fixing edge comprises a sleeve surrounded by the edges and the tensile layer and a columnar pin disposed in the sleeve. The bearing frame comprises a cavity for receiving the sleeve and the columnar pin and a groove allowing the net-shaped fabric to pass thereby.
In a class of this embodiment, the bearing frame is a rectangular frame formed by a pair of long edges and a pair of short edges. The fixing edge comprising the columnar pin are capable of rotating a circumference less than 6 cm in a reverse direction in a cavity formed by the long edges, and the rotation of the fixing edge can be fixed at any position.
In a class of this embodiment, multiple fixing edges are disposed on edges or strengthening edges of the net-shaped fabric that are connected to the bearing frame. The fixing edges are edges or strengthening edges fixed on a columnar pin, and the bearing frame comprises a cavity for receiving the fixing edges and a groove allowing the net-shaped fabric to pass thereby.
In a class of this embodiment, a rigid strip is disposed on the tensile layer. The width of the rigid strip is less than that of the tensile layer. The rigid strip and the tensile layer form a fixing edge. A hanging hole is disposed on the fixing edge. A hanging column is disposed on the bearing frame. The hanging hole and the hanging column form a removable positioning structure. A normal displacement of a fixing edge between adjacent hanging holes due to elastic bending is less than 5 mm.
In a class of this embodiment, the edges or the tensile layer of the net-shaped fabric is fixed on the bearing frame via an adhesive.
In a class of this embodiment, the bearing frame is a rectangular frame formed by a pair of long edges and a pair of short edges. The distances between the long edges and between the short edges are adjustable. An adjusting range of the distance between the long edges is no greater than 6 cm. An adjusting range of the distance between the short edges is no greater than 9 cm. The long edges simultaneously move in a reverse direction and the short edges separately move during adjustment, and the movement of the long edges and the short edges can be fixed at any position.
In a class of this embodiment, edges of the net-shaped fabric and the bearing frame mutually positioning each other correspond to hip curves and each has wave ruffling, and the wave ruffling is fixed in the tensile layer.
In a class of this embodiment, the width of the net-shaped fabric disposed between two edges of the bearing frame is 1 mm to 20 mm longer than the distance between the two edges of the bearing frame. The diameter or inscribed circle diameter of the mesh opening is less than 0.8 mm. The diameter of the warp and the weft is less than 0.27 mm. The thickness of the net-shaped fabric is less than 0.55 mm.
In a class of this embodiment, the diameter or inscribed circle diameter of the mesh opening is less than 0.3 mm. The diameter of the warp and the weft is less than 0.08 mm. The thickness of the net-shaped fabric is less than 0.16 mm.
In a class of this embodiment, the net-shaped fabric is a single-layered plain-weave structure interwoven by the warp and the weft. An error in length of the warp and the weft is within a range of ±20% of a rating value. An angle between the warp and the weft is greater than 60°.
In a class of this embodiment, the warp and the weft at the edges of the net-shaped fabric, especially at the edges of the net-shaped fabric connected to the bearing frame are densely interwoven.
In a class of this embodiment, a minimum space between two adjacent interwoven strips is 3 mm, and a maximum space between two adjacent interwoven strips is 50 mm.
In a class of this embodiment, a surface of the interwoven strip comprises grooves filled with a waterproof adhesive substance.
Advantages of the invention include: the net-shaped fabric comprises the mesh openings and dense warp and weft interwoven with each other and is fixed to the bearing frame along the edge thereof via the tensile layer, which ensures that the warp and the weft do not hurt skin of patients, guarantees good air permeability of the skin, prevents bedsore, and creates a good environment for recovery of burns. The dimensions of the materials specified herein are critical for achieving these advantages and are not a simple matter of engineering design choice.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a nursing bed of an exemplary embodiment of the invention;
FIG. 2 is a schematic view of a net-shaped fabric of the invention;
FIG. 3 is a partial enlarged view of FIG. 2 ;
FIG. 4 is a partial view of a net-shaped fabric;
FIG. 5 is another partial view of a net-shaped fabric;
FIG. 6 is a further partial view of a net-shaped fabric; and
FIG. 7 is a partially cross-sectional view of a tensile layer.
In the drawings, the following reference numbers are used:
1 —bearing frame; 2 —net-shaped fabric; 3 —tensile layer; 4 —fixing edge; 11 —cavity; 12 —groove; 21 —warp and weft; 22 —mesh opening; 23 —outlet; 24 —interwoven strip; 25 —wave ruffling; 31 —coverage area; 32 —half coverage area; 33 —soft fabric; 41 —sleeve; 42 —columnar pin; 43 —rigid strip; 44 —hanging hole; 45 —edges of the net-shaped fabric; and 46 —opposite edges of the bearing frame.
DETAILED DESCRIPTION OF THE EMBODIMENTS
As shown in FIG. 1 , a nursing bed of the invention comprises a bearing frame 1 and a net-shaped fabric 2 disposed within on the bearing frame 1 . The bearing frame 1 is disposed on a normal bedstead, or on a bedstead of a heat-insulating nursing bed with a temperature and humidity regulating function, or legs are disposed at four corners of the bearing frame 1 whereby forming a simple nursing bed.
The width of the net-shaped fabric 2 disposed between two opposite edges of the bearing frame 1 is 1 mm to 20 mm longer than the distance between the two opposite edges of the bearing frame 1 .
The diameter or inscribed circle diameter of the mesh opening is less than 0.8 mm, the diameter of the warp and the weft is less than 0.27 mm, and the thickness of the net-shaped fabric is less than 0.55 mm.
For better resolution of force applied by a patient, the net-shaped fabric 2 is slightly concave and loose and is not in a tension state so that elastic elongation or fracture does not occur.
As shown in FIG. 4 , the diameter or inscribed circle diameter of the mesh opening 22 on part of the net-shaped fabric 2 is less than 0.8 mm, the diameter of the warp and the weft 21 is less than 0.27 mm, and the thickness of the net-shaped fabric 2 is less than 0.55 mm.
The diameter or inscribed circle diameter of the mesh opening 22 on other part of the net-shaped fabric 2 is less than 0.3 mm, the diameter of the warp and the weft 21 is less than 0.08 mm, and the thickness of the net-shaped fabric 2 is less than 0.16 mm. The part of the net-shaped fabric 2 is more fine and close, which is optimized for treating the wound of skin of the patient. In details, the part is corresponding to wound that is pressed by the patient himself in bed, and an area thereof is larger than a wound area. Nurses can spray cleaning fluid or liquor on the wound via the mesh openings 22 .
An outlet 23 is disposed at a hip of the patient, and a tensile layer 3 is disposed at the edge of the outlet 23 , whereby reinforcing the net-shaped fabric 2 and preventing drawnwork or partial fracture.
As shown in FIGS. 1 and 2 , edges of the net-shaped fabric 2 and the bearing frame 1 mutually positioning each other correspond to the hip curve of the patient, and each has a wave ruffling 25 , and the wave ruffling 25 is fixed in the tensile layer 3 .
As shown in FIG. 4 , the net-shaped fabric 2 comprises a plurality of mesh openings 22 and a warp and a weft 21 interwoven in a vertical direction, an interweaving point of the warp and the weft 21 is fastened by a fixed connection, adhesive, or heating. As the adhesive is used, one of two adjacent interweaving points of the warp and the weft 21 is fastened by a fixed connection, and the other one thereof is fastened by an unfixed connection (as shown in a dashed line in FIG. 4 ). This ensure smooth surface of the net-shaped fabric and prevents the surface thereof from being contaminated by the adhesive.
In the invention, plain weave using square holes is used. Plain weave facilitates optimum effect in terms of stretch proofing of the net-shaped fabric, easy cleaning, the mesh opening, the thickness of the fabric, and so on. Preferably, the net-shaped fabric 2 is a single-layered plain-weave structure interwoven by the warp and the weft 21 , an error in length of the warp and the weft 21 is within a range of ±20% of a rating value, an angle between the warp and the weft 21 is greater than 60°. The mesh opening 22 is surrounded by a warp and a weft 21 .
As shown in FIG. 5 , a tensile layer 3 is disposed at the edge (also called cutting line) of the net-shaped fabric 2 , and the tensile layer 3 and the bearing frame 1 form a mutual positioning structure. The edge described hereinafter comprises surrounding edges, cutting edges, edges at the opening, and so on. The warp and the weft 21 at the edge of the net-shaped fabric, especially the edge of the net-shaped fabric connected to the bearing frame 1 are densely interwoven whereby improving tensile force at the edge.
As shown in FIG. 6 , a plurality of warp interwoven strips 24 or weft interwoven strips 24 are disposed on the net-shaped fabric 2 in a direction of either the warp or the weft or in directions of both of the warp and the weft, the width of the interwoven strip 24 is less than 3 mm, and the interwoven strips 24 are uniformly distributed on the net-shaped fabric 2 and in the shape of a pectination or a grid, whereby improving bearing capability and tensile capability of the fabric and positioning performance of the warp and the weft. The warp and the weft 21 on the interwoven strips 24 are fastened via a fixed connection. In an embodiment, adhesive is disposed on strip at the back of the net-shaped fabric 2 for connection. Optionally, a minimum space between two adjacent interwoven strips is 3 mm, and a maximum space between two adjacent interwoven strips is 50 mm. The surface of the interwoven strips comprises grooves filled with a waterproof adhesive substance.
As shown in FIG. 5 , the tensile layer 3 includes coating materials coated on the net-shaped fabric 2 , and the coating materials block or partially block the mesh openings 22 on the net-shaped fabric 2 . The edge of the net-shaped fabric 2 is completely coated by the coating materials, and the mesh openings on the edge of the net-shaped fabric 2 are completely blocked by the coating materials, forming a coverage area 31 as indicated in FIG. 5 . The thickness of the coating materials on the net-shaped fabric 2 becomes thinner from the edge of the net-shaped fabric 2 to the center thereof whereby forming a half coverage area 32 in which the mesh openings are partially blocked by the coating materials.
The coating materials are coated on an intersection point between the warp and the weft, and thickness thereof gradually decreases, or stepwisely decreases, whereby preventing sudden changes of intensity occurring at a junction between the tensile layer and the non-tensile layer. The coating materials are soft flexible structural adhesive, which is better than normal adhesive in terms of shear strength, tensile strength, peel strength, non-uniform tear strength, and so on.
The tensile layer 3 comprises one of a soft fabric 33 , a film, or a non-woven fabric that is coated and fixed on the net-shaped fabric 2 or on the coating materials coated on the net-shaped fabric 2 . The soft fabric 33 can be coated on one side or both sides of the net-shaped fabric 2 whereby improving strength thereof and implementing mutual positioning between the net-shaped fabric 2 and the bearing frame 1 .
As shown in FIGS. 1 and 7 , mutual positioning between the net-shaped fabric 2 and the bearing frame 1 is implemented by adhesion and is removable so that replacement, disassembly or cleaning is convenient. The specific method is as follows:
1. multiple fixing edges 4 are disposed on the tensile layer 3 of edges of the net-shaped fabric 2 and the bearing frame 1 mutually positioning each other, the fixing edge 4 comprises a sleeve 41 surrounded by the tensile layer 3 and a columnar pin 42 disposed in the sleeve 41 , and the bearing frame 1 comprises a cavity 11 for receiving the sleeve 41 and the columnar pin 42 and a groove 12 allowing the net-shaped fabric 2 to pass thereby. After the columnar pin 42 is pulled out, the net-shaped fabric 2 is separated from the bearing frame 1 , which is suitable for a bed partially using the net-shaped fabric 2 . In details, the net-shaped fabric 2 in FIG. 1 is a whole piece of net-shaped fabric 2 , or a partially used net-shaped fabric 2 , and is used for a hip of a patient during cleaning of defecation; other parts thereof can use normal fabrics that are assembled altogether.
2. multiple fixing edges 4 are disposed on the tensile layer 3 of edges of the net-shaped fabric 2 and the bearing frame 1 mutually positioning each other, the fixing edge 4 is a tensile layer 3 fixed on a columnar pin 42 , and the bearing frame 1 comprises a cavity 11 adapted to receive the fixing edges 4 and a groove 12 allowing the net-shaped fabric 2 to pass thereby. The columnar pin 42 is fixed to the tensile layer 3 , which features good integrity.
3. A fixing edge 4 is a rigid strip 43 disposed on the tensile layer 3 . As shown in FIG. 5 , the width of the rigid strip 43 is less than that of the tensile layer 3 , the rigid strip 43 and the tensile layer 3 form a fixing edge 4 , a hanging hole 44 is disposed on the fixing edge 4 , a hanging column is disposed on the bearing frame 1 , the hanging hole 44 and the hanging column form a removable positioning structure, and a normal displacement of a fixing edge between adjacent hanging holes due to elastic bending is less than 5 mm.
For example, the hanging holes 44 are uniformly disposed on the rigid strip 43 , the hanging column received in the hanging hole 44 is disposed on the bearing frame 1 . Mutual positioning between the hanging hole 44 and the hanging column makes disassembly convenient and replacement simple.
4. The simplest method is to fix the net-shaped fabric 2 on the bearing frame 1 along the tensile layer 3 via adhesion whereby forming a mutual positioning structure. The method features high requirement for operation of changing the net-shaped fabric but a simple structure.
To implement adjustment of tightness of the net-shaped fabric 2 on the bearing frame 1 , the bearing frame 1 is a rectangular frame formed by a pair of long edges and a pair of short edges, the distances between the long edges and between the short edges are adjustable, an adjusting range of the distance between the long edges is no greater than 6 cm, an adjusting range of the distance between the short edges is no greater than 9 cm, the long edges simultaneously move in a reverse direction and the short edges separately move during adjustment, and the movement of the long edges and the short edges can be fixed at any position.
Alternatively, the bearing frame 1 is a rectangular frame formed by a pair of long edges and a pair of short edges, the fixing edge comprising the columnar pin 42 are capable of rotating a circumference less than 6 cm in a reverse direction in a cavity 11 formed by the long edges, and the rotation of the fixing edge can be fixed at any position.
The net-shaped fabric 2 is disposed on two long edges, and the long edge of the nursing bed can be divided into multiple sections according to posture of the patient in bed, and the sections can be connected to each other via hinges whereby forming a sitting and sleeping bed.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A nursing bed, including at least a net-shaped fabric with a plurality of mesh openings and a bearing frame. The net-shaped fabric includes a warp and a weft. The diameter or inscribed circle diameter of the mesh opening is 2 to 6 times the diameter of the warp and the weft. The ratio of the sum of the areas of the mesh openings with respect to the area of the net-shaped fabric is 35% to 78%. The diameter or the inscribed circle diameter of the mesh opening is less than 1.5 mm. The diameter of the warp and the weft is less than 0.55 mm. The thickness of the net-shaped fabric is less than 1.1 mm. At least two edges of the net-shaped fabric are connected to two opposite edges of the bearing frame, respectively. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to training or kennel muzzles which are used to limit the actions of animals, typically dogs, during boarding and training.
The boarding and training of animals, particularly dogs prepared for racing careers, is a time-consuming, expensive process. The training subjects are energetic animals in training to be aggressive and highly reactive to certain stimuli. Most of the time, the animal is confined together with other dogs in a fenced enclosure or run. Considerable time frequently passes without the animals being closely observed.
In order to decrease the likelihood that an animal will cause injury either to itself or to another animal in the enclosure, the use of a training or kennel muzzle is strongly recommended and widely practiced. The kennel muzzle prevents animals from attacking each other, or chewing bedding or housing or enclosure material.
A training muzzle differs from the familiar racing muzzle which is especially designed to facilitate photo finishes to races and lacks any significant restraint or movement limiting capabilities. Typically, the racing muzzle is characterized by a white-banded basket having a single strap that slides over the head of the animal. The strap sits behind and under the ears of the animal. Normally, it is emplaced just prior to a race and then removed upon completion. Thus, the racing muzzle is not intended for long term use and is therefore of simplified design. As a result of the design of the racing muzzle, it is not uncommon for the dog to be able to remove this type of muzzle by its own actions in a short period of time. In contrast, the kennel muzzle is affixed to an animal for relatively long periods. For example, racing dogs are provided with a muzzle when ever they are in an enclosure. As a result, the kennel muzzle must be differently designed so as to reduce the ability of the animal to remove it.
The kennel muzzle includes two main features which are the headstall and a muzzle basket affixed thereto. The headstall fits about the animal's head and neck.
It is common practice to utilize a unitary construction for kennel muzzles wherein the headstall is permanently attached to the basket. The entire assemblage is then removed and replaced several times during the day. The muzzle basket is typically formed of a series of spaced wire or plastic ribs. Consequently, the basket is quite capable of becoming hooked to fencing or to any exposed projections. The potential to cause harm to the animal is present should the basket become ensnared and the animal held at this point. Normally, the headstall is made of leather or plastic coated nylon straps with a single riveted connection on each side to which the basket is affixed. The basket is not rigidly affixed to the headstall thereby permitting some limited movement in relation to the headstall. This movement has been found to promote another problem, the ability of the animal to move its mouth in relation to the basket enables the animal's mouth to frequently reach the attachment point. As a result, it is not uncommon for an animal to chew through the strap and effect a partial or full release of its kennel muzzle. This defeats the entire purpose of the device and increases the potential for the animal to either harm itself or other animals.
Accordingly, it is a primary objective of the present invention to provide a kennel muzzle. A headstall allowing quick release of the removable muzzle basket should the basket become ensnared. In addition, the present invention provides multiple attachment points to the basket thereby reducing relative movement between basket and headstall. Furthermore, the headstall is provided with an adjustable position throat strap to discourage movement of the animal in relation to the muzzle basket so that the ability of the animal to damage the headstall and perhaps release itself from the basket is greatly reduced.
SUMMARY OF THE INVENTION
This invention relates to a headstall for conformably resting upon the nose and neck of an animal and receiving a muzzle basket for removable attachment thereto. The headstall includes a headpiece which rests upon and projects forwardly toward the nose of the animal. The headstall also includes a pair of opposing lobes which downwardly depend and overlie the jaw of the animal. A neck strap extends rearwardly from the headpiece and rests upon the animals neck behind the ears while a throat strap attached to the neck strap partially encircles the throat. The combination of neck strap and throat strap maintain the headpiece in overlying position on the nose of the animal.
A muzzle basket is secured to the headstall by engaging means located on the opposing lobes. The engaging means provide the attachment points on each lobe for detachably securing the muzzle basket thereto. Each engaging means includes retaining clips that are inserted in a corresponding receiving socket in the lobes. When the basket is removed from the headstall, for example when caught on the fencing of the animals run, the retaining clips are pulled from the receiving sockets as a result of the animal's movement thereby freeing the animal. The headstall remains in position on the animal when detached from the basket.
The throat strap is movably attached to the neck strap so that is moves as the animal rotates his head to try to extract himself from the muzzle. As the throat strap moves back in response to rotation of the dog's head, the throat strap gets increasingly uncomfortable thereby encouraging the animal to stop trying to twist its head to promote movement within the headstall. As a result, the animal is discouraged from taking steps to free itself and damage the headstall. However, should the muzzle basket become attached to fencing, the rotation of the head and the headstall cause the headstall to detach from the muzzle basket.
Further features and advantages of the invention will become more readily apparent from the detailed description of a preferred embodiment thereof when viewed in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are side views of two embodiments of the invention showing the headstall in place on a dog's head both with and without a muzzle basket.
FIG. 3 is a partial view in perspective showing the engaging means for the basket.
FIG. 4 is a view in cross section showing a retaining clip for the muzzle basket.
FIG. 5 is a view in perspective of the headstall with the neck strap open.
FIG. 6 is a partial view in perspective showing a portion of a closed neck strap.
FIG. 7 is a partial cross section taken along line 7--7 of FIG. 6.
FIG. 8 is a bottom view of the headpiece of the embodiment of FIG. 1.
FIG. 9 is a side view of the retaining clip of FIG. 4.
FIG. 10 is an end view of the retaining clip shown in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, a preferred embodiment of the present invention is shown positioned on the head of a greyhound dog. As shown, the embodiment includes a headstall that conformably rests upon the nose and neck of the dog and contains a strap that resides adjacent its throat. The headstall includes a headpiece 11 with a forward extension 17 overlying the nose and two side lobes 12 downwardly depending from the headpiece. A rearwardly extending neck strap 15 is provided shown resting on the neck of the dog. In FIG. 2, the neck strap is shown drawn back from the normal rest position seen in FIG. 1 to show strap fastener 22. A throat strap 14 is affixed to the neck strap 15 by a movable guide 18 at each end and encircles the region of the throat. The throat strap may be provided with a fastener 21 as shown in FIG. 1 or, alternatively, a fixed length strap may be employed as shown in FIG. 2.
The headstall is designed to fit a variety of different animals. The strap fasteners 21 and 22 located on the throat and neck straps respectively permit length adjustment of both of these straps to accommodate different sizes and shapes of animals. The muzzle basket 20 of FIG. 2 is made slightly oversized as shown so that it can receive muzzles and snouts of different sizes therein. The muzzle basket 20 is detachably secured to the lobes 12 of the headstall by use of removable fasteners 30. The removal of the muzzle basket is readily accomplished by removal of the retaining clips 30 from the sockets 16 in order to permit the animal to feed. The muzzle basket is comprised of a plurality of ribs both transverse and longitudinal so as not to impede the flow of air.
The affixation of the basket 20 to the headstall is shown in greater detail in FIG. 3 wherein the inner transverse ribs 24 are joined by cross ribs 26 and 27 to form the body of the basket. In the preferred embodiment shown, the basket is made of a rigid plastic thereby reducing its weight. A pair of retaining clips 30 are located on the opposing sides of end rib 28 and are slidable therealong for alignment with a corresponding socket 16 in lobe 12. For reasons that will be later explained, the material used in the headstall in the present embodiment is a low density polyethylene to provide flexibility to the headstall. Since sockets 16 require an additional degree of rigidity to accommodate the retaining clips 30, stiffening ridges 19 bound each of the sockets 16 to enable the clips to be inserted and retained during normal use. It is important to note that two sockets are provided on each lobe so that there are four points of affixation for the muzzle basket. Since the headstall is going to rest against the animal's skin, the reenforcing ridges 19 are not provided on the inner surface of the headstall.
The retaining clip is shown in detail in the cross sectional view of FIG. 4 which is taken along line 4--4 of FIG. 3 and in the side and end views of a clip as shown in FIGS. 9 and 10. The retaining clip 30 includes an encircling section 34 terminating in prongs 31. A detent 32 is formed in each prong and a beveled surface 35 is provided at its outer end. The clips are fashioned from nylon in the embodiment shown to provide durability and flexibility. As a result, the prongs 31 can be urged together by finger pressure applied to diametrically opposed sections of the encircling portion 34. In FIG. 4, it is to be noted that the socket 16 formed in the lobes is provided with a shoulder 33. When the retaining clip 30 is placed about the end rib 28 of the muzzle basket, finger pressure by the installer causes the prongs 31 to move into an adjacent position and they are urged into the socket 16 along the beveled surfaces 35. When so inserted, the finger pressure is released and the prongs tend to move outwardly toward the normal position as shown in FIG. 10 wherein the detent 32 engages the shoulder 33. In practice, the clip is retained in position until a significant pressure is brought to bear on one of the sides of the encircling portion of the clip. Then, the flexibility of the clip coupled with the flexibility of the headstall permits the retaining clip to be rolled out of the socket along a beveled surface. This operation can be intentionally performed by a handler seeking to remove the basket or, most importantly, can be caused by the animal twisting the headstall in relation to the basket in the event it is ensnared on fences or the like. The retaining clip is formed of a flexible material and can be applied to a variety of muzzle baskets designed to accommodate the different muzzle structures of different animals. Also, the clips are movable along the end rib 28 so as to be received by different size headstalls.
Details of the strap fastener are shown in FIGS. 5, 6 and 7 wherein the neck strap fastener is shown prior to being coupled to the neck straps in FIG. 5. FIGS. 6 and 7 show the fastener in fixed position thereon. The neck straps 15 are provided with a plurality of holes 44 extending along their lengths to permit length adjustment. The strap fastener 22 includes a backplate 45 having a fixed guide 41 at each end. A central locating pin 42 is provided for insertion into the holes 44 of strap 15. Each guide contains a passageway 43 through which the ends of straps 15 pass in overlying relationship as shown in FIGS. 6 and 7. When the proper length adjustment is determined, the inner strap is aligned so that the locating pin extends through one of its holes 44 and the free end of the strap is pulled taut. The outer strap is fed through the passageway in the guide and one of its holes is aligned with the locating pin and the free end of this strap then inserted through the other fixed guide 41. The final position for the straps and the fastener 22 is shown in FIG. 6 with the free ends located both on the inside and the outside of the headstall. As seen in FIG. 7, the backplate 45 is curved to rest conformably against the neck of the animal. The ends of the neck straps do not then bear the weight of the headstall. A similar fastener 21 may be provided to enable length adjustment in throat strap 14. In the embodiment of FIG. 1, the throat strap fastener 21 is provided with a curved backplate 54 so as to conformably reside adjacent the throat of the animal. As shown in FIG. 2, a smooth surface throat strap is employed. This strap is movable and is used in situations where the skin of the animal is sensitive to the fasteners used on the throat of FIG. 1. The fixed length throat strap can be readily removed and replaced with another strap of different length to accommodate different animals. As shown in FIG. 10, a cylindrical insert 51 can be utilized in combination with clip 30 to receive a rib of smaller dimension, for example, a metal wire basket. The insert grasps the smaller rib and limits movement of the basket when installed.
The underside of the headpiece 11 is shown in FIG. 8. The neck straps 15 extend away from the central portion of the headpiece. The forward most edge of the headpiece is provided with a ridge 47 shown in FIG. 5 as well. A companion ridge 48 is located at the opposing end of the headpiece. These ridges comprise spacing members to promote airflow between the nose and the headpiece. When in position on the animal, the spacing members elevate the headpiece and create an opportunity for air to flow freely therebetween. This feature of the embodiment is significant in connection with kennel muzzles which are maintained in place on an animal for lengthy periods. The use of spacer members is preferred when compared with the use of aerating holes formed directly in the headpiece 11 or separate pads placed thereunder. The side lobes do not need spacing members since they are flexible and adapt to the larger contour of the muzzle basket. This oversize basket urges the lobes outwardly and away from the animal's skin.
The embodiment as shown on the animal in FIG. 2 is manufactured entirely from plastic so that there are no metal parts to pierce the skin of this or another animal and possibly cause infection. The device is light in weight. The basket is removably attached as previously mentioned by the use of the retaining clips. These clips will remove themselves from the socket through the torsion applied to the clips if the basket becomes ensnared. The rotation of the dog's head and the headstall promotes the unequal forces to the retaining clips so that the muzzle disengages and frees the dog from an otherwise life threatening position.
During normal use, the rotation of the animal's head tends to urge the throat strap 14 in a rearward direction to serve as an automatic choker thereby discouraging this type of movement. When the basket becomes hooked, it has been found that the dog ignores the discomfort resulting from rearward movement of the throat strap and rotates his head until the muzzle basket detaches from the headstall. This feature of the throat straps moving in guides 18 along the neck strap 15 does serve to limit attempts to gnaw the portion of the headpiece attaching to the neck strap. Furthermore, the side lobes 12 extend downwardly and cover the adjacent portion of the mouth thereby denying access to the juncture of the neck strap and headpiece. This further assists in denying the animal the opportunity to destroy the connection between neck strap and headpiece.
While the foregoing description has referred to a specific embodiment of the invention, it is to be noted that many modifications and variations may be made therein without departing from the scope of the invention as claimed. | A kennel muzzle for dogs wherein a flexible headstall overlies the nose and is secured by the combination of a neck strap and a movable throat strap. The headstall includes side lobes which extend downwardly over the ends of the mouth and include receiving sockets for the clips to removably fasten a muzzle basket thereto. The rotation of the dog's head will cause an ensnared basket to break away from the headstall thereby freeing the dog. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an optically active compound useful in the fields of liquid crystal display elements or liquid crystal light switching elements, and a liquid crystal composition containing the same. More particularly it relates to a novel liquid crystalline compound having optically active groups and a liquid crystal composition containing the same, and exhibiting a chiral nematic phase or chiral smectic phase.
In addition, the liquid crystalline compound referred to herein is not limited only to compounds having a liquid crystal state which can be observed by themselves, but also it includes substances which, even when no liquid crystal state can be observed by themselves, have a chemical structure similar to that of the former and also are useful as an additive.
2. Description of the Related Art
It is well known that the importance of optically active substances in liquid crystal compositions used for electrooptical elements utilizing liquid crystal phases, i.e. liquid crystal elements or liquid crystal light switching elements, consists in the usefulness of constituting components of
(i) cholesteric phase (chiral nematic phase) and
(ii) chiral smectic phase.
It is also well known that the cholesteric phase (Ch phase) may be composed of as main components, compounds which exhibit Ch phase by themselves, but also may be composed by adding optically active substances to nematic phase and in the latter case, it is unnecessary that the added optically active substances exhibit liquid crystal phases by themselves. It is also known that Ch phase is utilized for display elements utilizing cholesteric-nematic phase transition, and besides, Ch phase is also utilized in place of nematic phase in order to prevent the so-called reverse domain from occurring. Further, optically active substances have been used as a constituting component of cholesteric liquid crystal compositions used for STN mode (a mode having the twist angle of liquid crystals enlarged up to 180°-270°) which is one of relatively new display modes; thus the importance of optically active substances has been more and more increasing.
On the other hand, an electrooptical element using chiral smectic liquid crystals has recently been noted. This element utilizes ferroelectricity of liquid crystals and this novel display mode has a possibility of notably improving the response rate (Clark et al, Applied Phys. lett., 36, 899 (1980)). This display mode is directed to a method utilizing chiral smectic phases exhibiting ferroelectricity such as chiral smectic C phase (hereinafter abbreviated to SC* phase). Ferroelectricity-exhibiting phases are not limited to SC* phase, but chiral smectic F, G, H, I and the like phases have been known to also exhibit ferroelectricity. When these ferroelectric liquid crystals are used for display elements, liquid crystal materials exhibiting ferroelectric liquid crystal phases within a broad temperature region including room temperature have been desired. At present, however, no single compound which satisfies such a requirement has been known; thus liquid crystal compositions which satisfy such required characteristics as much as possible have been prepared and used.
Chiral smectic liquid crystal compositions may also be composed of, as their main component, compounds which exhibit a chiral smectic phase by themselves, as in the case of the Ch phase, but the composition may also be composed by adding optically active substances to smectic phase and in this case, too, it is unnecessary that the added optically active substances exhibit liquid crystal phases by themselves.
SUMMARY OF THE INVENTION
The present inventors have searched for various compounds in order to find liquid crystalline, optically active compounds useful as a component of the above-mentioned liquid crystal compositions, and have achieved the present invention.
The present invention in a first aspect resides in a compound expressed by the formula ##STR3## wherein R 1 represents an alkyl group or an alkoxy group each of 1 to 18 carbon atoms, R 2 represents an alkyl group of 2 to 18 carbon atoms or an alkoxy group of 1 to 18 carbon atoms, --A-- represents ##STR4## wherein X represents a halogen atom or cyano group, m represents an integer of 0 to 12 and * indicates an asymmetric carbon atom.
The present invention in a second aspect resides in a liquid crystal composition containing at least one member of the above-mentioned compounds of the formula (I), particularly a chiral smectic liquid crystal composition.
The present invention in a third aspect resides in an electrooptical element using the above-mentioned liquid crystal composition.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
R 1 in the formula (I) is preferably an alkyl group or an alkoxy group each of 3 to 16 carbon atoms, more preferably an alkyl group or an alkoxy group each of 5 to 10 carbon atoms.
R 2 is preferably an alkyl group of 2 to 12 carbon atoms or an alkoxy group of 1 to 12 carbon atoms, more preferably an alkyl group of 2 to 8 carbon atoms or an alkoxy group of 1 to 6 carbon atoms.
The optically active compounds of the present invention mostly exhibit no liquid crystal properties by themselves, but when they are used as a component of ferroelectric liquid crystal compositions, it is possible to enhance the spontaneous polarization value Ps of the compositions.
Here, the importance of the spontaneous polarization value will be described. In general, the response time τ of ferroelectric liquid crystal display elements is expressed by the following equation (II): ##EQU1## wherein η: viscosity and E: intensity of electric field. As apparent from the equation (II), reduction in the response time is effected by increasing the Ps or by reducing the viscosity.
When the compound of the present invention is used as a component of ferroelectric liquid crystal compositions even if it exhibits no liquid crystal phase, it has a function of notably increasing the Ps of the ferroelectric liquid crystal compositions and as a result, it is possible to shorten the response time. As will be described later in an Example, for example when a compound of the present invention ##STR5## is added in an amount of 10% by weight to a liquid crystal composition exhibiting achiral smectic C phase (which composition exhibits no spontaneous polarization), a ferroelectric liquid crystal composition having a large spontaneous polarization value is obtained, which has a response time as short as 55 μsec at 25° C. (see Example 4).
This composition was compared with a liquid crystal composition obtained by adding an optically active compound disclosed in Japanese patent application laid-open No. Sho 63-126842/1988, ##STR6## in an amount of 10% by weight to the above-mentioned achiral smectic C liquid crystal composition. As a result, the response time of the former was 55 μsec, whereas that of the latter was 100 μsec under the same conditions. As seen from this fact, when the compound of the present invention is used, it is possible to prepare a composition having a very short response time.
Further, when the compound of the formula (I) of the present invention is added to a liquid crystal composition exhibiting chiral smectic C phase, but having a very small Ps value, it is possible to raise the Ps value up to a practical value. In short, it can be said that the compound of the present invention is far superior as a component bearing the Ps of ferroelectric liquid crystal compositions.
Further, since the compound of the formula (I) of the present invention has optically active carbon atoms, it has a capability of inducing a twist structure by adding the compound to nematic liquid crystals. Nematic liquid crystals having a twist structure, i.e. chiral nematic liquid crystals, do not form the so-called reverse domain (stripe pattern) of TN mode display elements; hence the compound of the formula (I) is usable as an agent for preventing the reverse domain from occurring.
Chiral nematic liquid crystal compositions obtained by adding the compound of the present invention to nematic liquid crystals have short chiral pitches; hence the compound of the present invention is useful as an agent for adjusting the chiral pitch.
Further, the temperature dependency of pitch (δP) expressed by the equation ##EQU2## wherein P(t 1 ) and P(t 2 ) represent pitch length (μm) measured at t 1 °C. and t 2 °C., respectively, was very large as shown later in Example 2.
The compound of the present invention may be prepared, e.g. through the following route: ##STR7##
Namely, compound (1) is reacted with compound (2) to obtain a compound expressed by the formula (I).
Here, as to the absolute configuration of the compound of the formula (I), if the absolute configuration of the d compound (1) having a plus rotatory polarization is expressed by d' and that of the l compound (1) is expressed by l', the compound of the formula (I) of d' and that of l' are obtained from the above-mentioned d compound and l compound, respectively.
The compound and composition of the present invention will be described in more detail by way of Examples.
EXAMPLE 1
Preparation of (1l',2S)-4-(1-(2-butoxypropionyloxy)ethyl)-4'-octyloxybiphenyl (a compound of the formula (I) wherein R 1 represents octyloxy group, R 2 represents butoxy group, --A-- represents ##STR8## m represents 0 and the absolute configuration of the asymmetric carbons is (1l',2S))
l'-4-(1-Hydroxyethyl)-4'-octyloxybiphenyl prepared according to the process disclosed in Japanese patent application laid-open No. Sho 63-126836/1988 ([α] d 25 ° -27.0° (C 1.0, CHCl 3 ), m.p. 124° C.) (5 g) was dissolved in dichloromethane (200 ml), followed by dissolving in the solution, N,N'-dicyclohexylcarbodiimide (hereinafter abbreviated to DCC) (5.4 g) and 4-N,N-dimethylaminopyridine (hereinafter abbreviated to DMAP) (1.0 g), adding 2-butoxypropionic acid (4.8 g) to the resulting solution, agitating the mixture at room temperature for 6 hours, filtering off deposited crystals, washing the filtrate with 6N-hydrochloric acid, then with 2N-NaOH aqueous solution and further with water until the washing water became neutral, distilling off the solvent and recrystallizing the residue from ethanol to obtain the objective compound (5.7 g) ([α] D 23 .5° -96.1° (C 1.28, CHCl 3 )). M.P.: 30° C.
EXAMPLE 2
Example 1 was repeated except that l'-4-octyloxy-4'-(1-hydroxyethyl)biphenyl was replaced by d'-4-octyloxy-4'-(1-hydroxyethyl)biphenyl ([α] D 23 .5° +29.8° (C 1.14, CHCl 3 ), m.p. 125° C.) to obtain (1d',2S)-4-(1-(2-butoxypropionyloxy)ethyl)-4'-octyloxybiphenyl (3.2 g) ([α] D 23 .5° +42.3° (C 1.42, CHCl 3 ). M.P.: 18° C.
Concrete examples of the compound of the formula (I) prepared in the same manner as in Example 1 or Example 2 are listed as follows:
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-pentylbiphenyl oil at r.t.
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-pentylbiphenyl
(1l',2S)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-pentylbiphenyl
(1d',2S)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-pentylbiphenyl
(1l',2S)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-pentylbiphenyl
(1l',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-pentylbiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-pentylbiphenyl
(1d',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2R)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1d',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2R)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1d',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-octylbiphenyl
(1d',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-3'-cyano-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-octylbiphenyl
(1l',2R)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Propoxypropionyloxy)ethyl)-3'-cyano-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2R)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2R)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-hexyloxybiphenyl
(1d',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2R)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1d',2R)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Methoxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1d',2S)-4-(1-(2-Ethoxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1l',2R)-4-(1-(2-Propoxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1l',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-octyloxybiphenyl m.p. 30° C. (Example 1)
(1d',2S)-4-(1-(2-Butoxypropionyloxy)ethyl)-4'-octyloxybiphenyl m.p. 18° C. (Example 2)
(1l',2S)-4-(1-(2-Pentyloxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1l',2S)-4-(1-(2-Hexyloxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1l',2S)-4-(1-(2-Heptyloxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1l',2S)-4-(1-(2-Octyloxypropionyloxy)ethyl)-4'-octyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3'-fluoro-4'-pentylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-pentylbiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-3-cyano-4'-pentylbiphenyl
(1l',2S)-4-(1-(2-Methylpentanoyloxy)ethyl)-4'-pentylbiphenyl
(1d',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-pentylbiphenyl
(1l',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-pentylbiphenyl
(1l',6S)-4-(1-(6-Methyloctanoyloxy)ethyl)-4'-pentylbiphenyl
(1l',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-4'-pentylbiphenyl
(1d',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Methylpentanoyloxy)ethyl)-4'-hexylbiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-3'-bromo-4'-hexylbiphenyl
(1l',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-hexylbiphenyl
(1l',5S)-4-(1-(5-Methyloctanoyloxy)ethyl)-4'-hexylbiphenyl
(1l',6S)-4-(1-(6-Methylnonanoyloxy)ethyl)-4'-hexylbiphenyl
(1l',7S)-4-(1-(7-Methyldodecanoyloxy)ethyl)-4'-hexylbiphenyl
(1d',5S)-4-(1-(5-Methyldecanoyloxy)ethyl)-4'-hexylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-cyano-4'-heptylbiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-4'-heptylbiphenyl
(1l',3S)-4-(1-(3-Methylhexanoyloxy)ethyl)-4'-heptylbiphenyl
(1l',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-heptylbiphenyl
(1l',4S)-4-(1-(4-Methylheptanoyloxy)ethyl)-4'-heptylbiphenyl
(1d',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-4'-heptylbiphenyl
(1l',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-3'-cyano-4'-heptylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Methylpentanoyloxy)ethyl)-4'-octylbiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-4'-octylbiphenyl
(1d',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-octylbiphenyl
(1l',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-cyano-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3'-cyano-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-fluoro-4'-octylbiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3'-cyano-4'-pentuloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3'-fluoro-4'-pentyloxybiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',6S)-4-(1-(6-Methyloctanoyloxy)ethyl)-4'-pentyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-cyano-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-fluoro-4'-hexyloxybiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-4'-hexyloxybiphenyl
(1d',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-4'-hexyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-cyano-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-3-fluoro-4'-heptyloxybiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-heptyloxybiphenyl
(1d',7S)-4-(1-(7-Methyldodecanoyloxy)ethyl)-4'-heptyloxybiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-3'-cyano-4'-heptyloxybiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-3'-fluoro-4'-heptyloxybiphenyl
(1l',2S)-4-(1-(2-Methylbutanoyloxy)ethyl)-4'-octyloxybiphenyl
(1d',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-4'-octyloxybiphenyl
(1l',3S)-4-(1-(3-Methylpentanoyloxy)ethyl)-3-fluoro-4'-octyloxybiphenyl
(1l',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-octyloxybiphenyl
(1d',4S)-4-(1-(4-Methylhexanoyloxy)ethyl)-4'-octyloxybiphenyl
(1l',5S)-4-(1-(5-Methylheptanoyloxy)ethyl)-4'-octyloxybiphenyl
(1l',6S)-4-(1-(6-Methyloctanoyloxy)ethyl)-4'-octyloxybiphenyl
(1l',7S)-4-(1-(7-Methylnonanoyloxy)ethyl)-4'-octyloxybiphenyl
(1l',8S)-4-(1-(8-Methyldecanoyloxy)ethyl)-4'-octyloxybiphenyl
EXAMPLE 3 (USE EXAMPLE 1)
(1l', 2S)-4-(1-(2-butoxypropionyloxy)ethyl)-4'-octyloxybiphenyl prepared in Example 1 was added in an amount of 1% by weight to ZLI-1132 made by Merck Company to obtain a chiral nematic liquid crystal composition, and the chiral pitch of this composition was measured according to Cano wedge method to give 35.9 μm at 20° C. and 76.5 μm at 60° C.
Further, the temperature dependency of the chiral pitch (δP) was +1.807 in the range of 20° to 60° C.
EXAMPLE 4 (USE EXAMPLE 2)
A nematic liquid crystal composition consisting of ##STR9## was filled in a cell provided with transparent electrodes each obtained by coating polyvinyl alcohol (PVA) as an aligning agent, followed by rubbing the resulting surface to subject it to a parallel aligning treatment, and having a distance between the electrodes of 10 μm to prepare a TN mode display cell, which was then observed under a polarizing microscope. As a result, a reverse domain was observed to be formed.
To the above nematic liquid crystal composition was added the compound of Example 1 as a compound of the present invention, i.e. ##STR10## in an amount of 1% by weight, followed by similarly observing the mixture in a TN mode cell. As a result, the reverse domain was dissolved and a uniform nematic phase was observed.
EXAMPLE 5 (USE EXAMPLE 3)
An achiral smectic liquid crystal mixture consisting of ##STR11## was prepared. This mixture had a m.p. of 4° C. exhibited SC phase at temperatures higher than the m.p. and nematic phase at 79° C. and formed isotropic liquid at 90° C.
To 90% by weight of this mixture was added the compound of Example 1 as a compound of the present invention (10% by weight) to prepare a chiral smectic liquid crystal composition. Its phase transition points were as follows: SC* phase at temperatures lower than 35° C., SA phase at 35° C., Ch phase at 70.2° C. and isotropic liquid at 80.8° C.
The composition was filled in a cell of 2 μm thickness provided with transparent electrodes each obtained by coating PVA as an aligning agent, followed by rubbing the resulting surface to subject it to a parallel aligning treatment to obtain a liquid crystal display element, which was then placed between crossed polarizer and analyzer, followed by impressing a voltage of ±10 V. As a result, change in the intensity of transmitted light was confirmed.
The response time was sought from the change in the intensity of transmitted light at that time to give about 55 μsec at 25° C.
The liquid crystal composition had a spontaneous polarization value of 4.0 nC/cm 2 at 25° C. and a tilt angle of 10.4°. | A liquid crystalline, optically active compound useful as a component of various liquid crystal compositions, a liquid crystal composition containing the same and a light switching element using the liquid crystal composition are provided, which liquid crystalline, optically active compound is expressed by the formula ##STR1## wherein R 1 is 1-18C alkyl or alkoxy, R 2 is 2-18C alkyl or 1-18C alkoxy, A is ##STR2## wherein X is halogen or CN, m is 0 to 12, and * indicates an asymmetric carbon atom. | 2 |
This application is a United States National Phase application of PCT Application No. PCT/US2006/030761 filed Aug. 8, 2006.
BACKGROUND OF THE INVENTION
This application relates to a pulse width modulation control for a suction valve that allows for continuous and precise capacity adjustment to be provided by a refrigerant system in efficient and cost effective manner, and wherein compressor temperature is monitored to determine an optimum duty cycle for the pulse width modulation method from performance, comfort and reliability perspectives.
Refrigerant systems are utilized in many applications such as, for example, condition an indoor environment or refrigerated space. For instance, air conditioners and heat pumps are used to cool and/or heat the air entering an environment. The cooling or heating load in the conditioned environment may change with ambient conditions, internal thermal load generation, and as the temperature and/or humidity levels demanded by an occupant of the environment or requirements for the conditioned space are varied. Therefore, the refrigerant system operation and control have to adequately react to these changes in order to maintain stable temperature and humidity conditions within the environment, while preserving functionality, performance and efficiency as well as sustaining reliable operation.
One method that is known in the prior art to assist in the adjustment of capacity provided by a refrigerant system is the use of a pulse width modulation control. It is known in the prior art to apply a pulse width modulation control to cycle a suction valve at a certain rate for controlling the flow of refrigerant to a compressor, to in turn adjust refrigerant system capacity. Since the pulse width modulation valve is typically cycled between fully open and fully closed (or nearly fully closed) positions, minimal additional throttling or other noticeable performance losses are imposed during such part-load operation. By limiting the amount of refrigerant flow passing through the compressor, the capacity can be reduced to a desired level below a full-load capacity (approximately down to 5% of the total capacity) of a refrigerant system to precisely match the thermal load in a conditioned environment.
One problem raised by pulse width modulation of a suction valve is that a flow of refrigerant delivered into the compressor suction port may be significantly reduced. In many compressor designs, the suction refrigerant passes over the motor, to cool the motor. If the amount of refrigerant flowing through the compressor suction port is significantly reduced, it may not adequately cool the motor. The motor temperatures may increase dramatically and exceed a specified limit that in turn may lead to permanent motor damage and catastrophic failure. Moreover, since a lower amount of refrigerant is relied upon to cool the motor, that refrigerant can become excessively hot and may transfer this heat to other compressor components, overheating these components, including oil lubricating the compressor elements, which is highly undesirable. Also when compressor operates in a pulse width modulation mode, during the portion of the cycle when the pulse width modulation valve is closed or nearly closed, the operating pressure ratio can reach very high values. High pressure ratio operation coupled with excessive motor heat can lead to high discharge temperatures at the compressor discharge or within the compression elements. Thus, if the pulse width modulation technique is setup to cycle through relatively long periods of a suction valve being closed or nearly closed, the compressor components, oil and refrigerant can become extremely hot, leading to potential compressor reliability problems and nuisance shutdowns. Additionally, thermal inertia of a refrigerant system may not be sufficient enough to overcome and prevent temperature and humidity variations in a conditioned environment, causing occupant discomfort or hampering refrigeration.
On the other hand, if the valve is cycled too frequently to minimize the upper temperature excursions, the risk of suction valve failure may increases due to the extensive cycling, as well as secondary instability effects may propagate throughout the system interfering with its proper functionality.
Consequently, there is a need for a method to control a duty cycle for a pulse width modulation valve to eliminate all undesired phenomena mentioned above.
SUMMARY OF THE INVENTION
In a disclosed embodiment of this invention, a pulse width modulation control is provided for selectively varying the amount of refrigerant flow passing from an evaporator downstream to the compressor. By adjusting the amount of refrigerant flowing through a suction valve controlled by a pulse width modulation technique, the capacity provided by the refrigerant system can be continuously and precisely adjusted to match thermal load requirements in a conditioned environment. A control monitors parameters indicative of a compressor temperature, and ensures that the temperature does not exceed a specified limit (within a tolerance band).
The duty cycle of the suction valve controlled by a pulse width modulation method is selected to ensure that the temperature stays below the predetermined limit. In a disclosed embodiment, the temperature associated with compressor temperature is monitored either at the motor, the compressor unit, the discharge tube, at the exit from the compressor pump-set, or any other relevant location. Should the temperature approach the predetermined limit, the pulse width modulation cycling rate of the suction valve is adjusted to a higher value to keep the temperature below the specified limit. Similarly, as long as the temperature is maintained below such a threshold, no adjustment to the valve cycling rate may be required. On the other hand, if the cycling rate (the number of cycles per unit of time) is excessive (for instance, from valve reliability considerations), then the control may lower this rate, while still keeping the measured temperature below the predetermined threshold.
Further, the cycling rate can be also adjusted based upon operating conditions, allowable temperature and humidity variations within a conditioned environment, reliability limitations of the suction valve, refrigerant system efficiency goals, system thermal inertia, operation stability and functionality considerations, etc. Alternatively, some adaptive control can be utilized wherein the control “learns” how variations in the duty cycle will result in changes in the compressor temperature. A worker of ordinary skill in the art would recognize how to provide such a control.
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 shows a schematic of a refrigerant system incorporating the present invention.
FIG. 2 shows a time versus pressure chart of a pulse width modulation control, including a temperature over time trend.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A refrigerant system 20 is illustrated in FIG. 1 having a compressor 22 compressing a refrigerant and delivering it downstream to a condenser 24 . The refrigerant passes downstream to an expansion valve 28 , and then to an evaporator 30 . A suction valve 34 controlled with a pulse width modulation signal is positioned downstream of the evaporator 30 and upstream of the compressor 22 suction tube 100 . A control 35 adjusts and maintains the duty cycle parameters for the suction valve 34 controlled with the pulse width modulation signal.
As shown, a temperature sensor 36 is associated with the motor 102 of the compressor 22 . As is known, the refrigerant enters the compressor through the suction tube 100 , and flows over the motor 102 driving a compressor pump unit 104 . In the disclosed embodiment, the compressor is a scroll compressor including an orbiting scroll member 105 , which is driven by the motor 102 , and a non-orbiting scroll member 108 . Further, a discharge tube 106 receives a compressed refrigerant and delivers it to the condenser 24 , as known. Temperature sensor 136 is shown on the discharge tube. Temperature sensor 236 is shown associated with the compressor pump unit 104 , and in particular with the non-orbiting scroll 108 . Any one of these locations are acceptable locations for providing a temperature feedback to the control 35 . Of course, any other locations to measure relevant compressor or refrigerant temperatures are also feasible. For example a temperature sensor can be installed to measure an oil temperature within the compressor sump or to measure the oil temperature as it has been returned back to the compressor sump after it passed through various components within the compressor to cool these components. As shown in FIG. 1 , a temperature sensor 47 can be installed near or on the oil return tube 48 that drains the oil back to the compressor sump. Also, a temperature sensor 49 can be installed to measure the oil temperature in the compressor sump 52 . Furthermore, the temperature sensor can be installed to monitor temperature within the compression process or positioned immediately after the location where refrigerant leaves the compression elements, as shown by sensor installation 51 .
As mentioned above, the refrigerant from the suction tube 100 flows into an internal compressor chamber 115 and then over the motor 102 , to cool the motor. However, when the control 35 has closed or nearly closed the valve 34 (during an oil-cycle), the refrigerant flow over the motor is drastically reduced. Since the motor continues to operate, although at a significantly reduced load, it may not be adequately cooled, and its temperature may increase above the allowable limit that in turn may lead to permanent motor damage and catastrophic failure. Moreover, since a lower amount of refrigerant is relied upon to cool the motor, that refrigerant can become excessively hot and may transfer this high temperature heat to other compressor components and oil lubricating the compressor elements, which is highly undesirable. Additionally, when the pulse width modulation valve is closed or nearly closed, a suction pressure at the compressor entrance is very low; this leads to a very high operating pressure ratio (a ratio of a discharge pressure to a suction pressure). High pressure ratio operation coupled with excessive motor heat can lead to high discharge temperatures at the compressor discharge or within the compression elements. The present invention monitors the relevant temperature at a location 36 , 136 , or 236 , or a combination of thereof, and changes the parameters of a duty cycle to ensure that the temperatures associated with the compressor operation will not become excessively high. For purposes of this invention, any of the locations mentioned above, or any other location where a temperature is indicative of the temperature within the compressor, may be utilized. Further, while a scroll compressor is shown, any other type of a compressor may benefit from this invention, such, as for example, a screw compressor, a rotary compressor or a reciprocating compressor.
As shown in FIG. 2 , the duty cycle of the suction valve 34 is controlled with a pulse width modulation signal. The pulse width modulation valve 34 is cycled between a closed position (corresponding to a flat peak position “P”) and an open position (corresponding to a flat valley position “V”). It should be noted that the suction valve 34 is preferably a normally open valve, so as, in the event of a failure, it stays open and does not compromise system reliability. In a disclosed embodiment, the suction valve 34 is, for instance, a solenoid valve that is capable of rapid cycling. The present invention changes the duty cycle, or the time interval over which the valve is in the open and closed positions.
FIG. 2 also shows a compressor temperature that may be the temperature monitored by any of the sensors of FIG. 1 . An upper limit L U is set. Also, the operational temperature target value L O may be set, at which system operation is desirable, while not allowing any excursions to exceed the upper Limit L U The measured temperature is maintained below that limit L U , with a target temperature value to be at L O or below. As long as the temperature is not exceeding the limit (within the tolerance band defined by the measurement accuracy, manufacturing variability, installation tolerance, etc.), the valve is cycled at a relatively slow rate, while still achieving the desired capacity, complying with temperature and humidity variation requirements in a conditioned environment and not overshadowing the thermal inertia of the refrigerant system. As the temperature approaches the upper limit L U , the suction valve 34 is cycled at a higher rate, which should reduce the relevant temperature T C to bring it closer to the target temperature value L O . It should be noted that the extremely high cycling rate might be limited by the suction valve reliability and secondary instability effects propagating through the refrigerant system 20 . Sometimes, it might also be desirable to maintain the temperature above a certain preset value. In this case, the control will adjust the cycling rate to assure that the temperature does not drop below a certain specified temperature. This may occur, for example, as the temperature of the compressor oil in the oil sump 52 needs to be maintained above a certain value to assure that the oil viscosity is not increased above a certain threshold that might be detrimental to oil delivery to the compressor components. In other instances, the control may adjust the cycling rate so that the peak-to-peak value of temperature fluctuations stays within a certain range. This might be desirable when the component damage may occur due to high fluctuations from a low to high temperature, causing thermal fatigue.
As can be appreciated from FIG. 2 , in a region “X” of a temperature graph, the measured temperature T C is approaching the upper limit L U . A duty cycle, or the time over which the peaks “P” and valleys “V” have existed as the valve is opened and closed, is relatively long. However, when the control 35 senses that the temperature is about to become excessively high or rising at an unacceptably high rate to approach the upper limit value L U (as illustrated over region “X”), the duty cycle becomes more rapid (cycle time is reduced) such that the valve stays open and closed over shorter time intervals. By reducing the cycle time t CYCLE , over which the valve is opened and closed, the lower peak temperature is achieved, and the temperature trend is reversed, to move away from the specified upper threshold L U , as is illustrated downstream of the region “X” on the graph. The present invention thus achieves suction valve control with a pulse width modulation signal, while addressing the temperature concerns set forth above. It has to be noticed that the capacity provided by the refrigerant system 20 is predominantly controlled by the ratio of time intervals over which the valve remains in the open and closed positions, and is practically independent of the cycling rate. Therefore, the refrigerant system capacity is not affected and controlled independently.
Further, the cycling rate can be also adjusted based upon operating conditions, allowable temperature and humidity variations within a conditioned environment, reliability limitations of the suction valve, refrigerant system efficiency goals, system thermal inertia, and operation stability and functionality considerations.
In another feature, the control can be an adaptive control that “remembers” changes in the duty cycle, which have been provided in the past, and the resultant changes in temperature. Thus, the control can “learn” over time to better control the temperature, and to result in a pulse width operation at the temperatures that are at desired levels. The control also can hunt for the best way to cycle the pulse width modulated valve by trying different cycling rates to establish which cycle rate would produce the best results within the imposed constraints, for example, on the maximum cycling rate of the valve.
Further, the pulse width modulated suction valve may have open and closed states corresponding to not necessarily fully open and fully closed positions, which provides additional flexibility in system control and operation. Additionally, if the temperature cannot be brought within the acceptable limits by reducing the cycle time as described above, then the length of time when the valve remains in the closed positions can be reduced (while maintaining the same time when the valve remains in the open position). In this case, the unit will produce more capacity than required to cool the conditioned environment to a preset level, thus some amount of unit cycling (completely turning off the compressor) may be necessary to precisely match delivered and required capacity.
Pulse width modulation controls are known, and valves operated by the pulse width modulation signal are known. The present invention utilizes this known technology in a unique manner to achieve goals and benefits as set forth above. Further, while temperature values are mentioned and are associated with the compressor, other measured parameters (e.g. current, power draw, etc.) may be indicative of the actual temperatures within the compressor. For example, the temperature within the compressor can be computed indirectly, based on the knowledge of other measured parameters such as suction and discharge pressure, voltage, etc. For purposes of this application, these parameters will still be within the scope of the claims for controlling the operation of the suction valve 34 to control temperature at desired locations within or outside of the compressor.
Although FIG. 1 illustrates a scroll compressor, the invention extends to other type of compressors, including (but not limited to) screw compressors, rotary compressors and reciprocating compressors. This invention can also be applied to a broad range of air conditioning systems, heat pump systems and refrigeration systems. Examples of such systems include room air conditioners, residential air conditioning and heat pump installations, commercial air conditioning and heat pump systems and refrigeration systems for supermarkets, container, and truck trailer applications.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. | A refrigerant system is provided with a pulse width modulation valve. A compressor temperature is monitored to prevent potential reliability problems and compressor failures due to an excessive temperature inside the compressor. A control changes the pulse width modulation valve duty cycle rate to maintain temperature within specified limits, while achieving the desired capacity, and complying with design requirements of a conditioned environment, without compromising refrigerant system reliability. As the compressor temperature increases, the pulse width modulation valve duty cycle time is adjusted to ensure that adequate amount of refrigerant is circulated through the compressor to cool the compressor internal components. | 5 |
BACKGROUND
1. Field
This invention is generally related to wireless communications, and more particularly, to techniques for reducing or eliminating DC (direct current) offset in transmission paths.
2. Background
Signal paths in radio frequency (RF) transmitters sometimes have undesirable DC offsets. DC offset often refers to a relatively constant offsetting of a signal from zero. In other circumstances, DC offset may alternatively refer to offsetting that occurs between differential signals. In contemporary digital communication systems, such as mobile cellular systems, the latter type of DC offset, that occurring between differential signals, may be particularly problematic. For example, in digital communication systems transmitting in-phase (I) and quadrature (Q) signal components, undesirable DC offsets may occur between differential signals representing the I and Q components, such as I p , I m , Q p and Q m differential signals. Such DC offsets may result in LO (local oscillator) carrier leakage and a degradation of EVM (error vector magnitude).
A DC offset may be due to mismatches in a signal path. For example, the DC offset may be due to mismatches between circuit components and/or leakage from circuit components along the path. DC offsets are typically inherent, undesirable aspects of active analog circuitry that generally must be eliminated or reduced before the signal is up-converted and transmitted.
Various techniques have been employed to minimize DC offset in transmitters. However, the previous attempts remain inadequate to address the DC offsets found in certain communication technologies, such as mobile cellular systems.
SUMMARY
Disclosed herein is a new and improved approach to reducing or eliminating DC (direct current) offsets in mobile communication system transmitters.
In accordance with an aspect of the approach, an apparatus generates a transmitted signal with a reduced DC offset. The apparatus may include a converter, a digital engine, and a plurality of programmable current supplies. The converter is configured to provide digital representations of a plurality of DC currents associated, respectively, with a plurality of differential signal legs. The digital engine is configured to receive the digital representations and to produce instructions for generating compensating currents for the plurality of differential signal legs based on comparisons, respectively, between each of the digital representations and a calibration current. The programmable current supplies correspond, respectively, to the differential signal legs The current supplies are configured to inject the compensating currents into the differential signal legs, respectively, to reduce DC offset between the differential signal legs, based upon the instructions.
In accordance with another aspect of the approach, a method of reducing DC offset in a transmission path generally includes determining a plurality of DC currents, where the DC currents are respectively associated with a plurality of differential signal legs in the transmission path; selecting a calibration current; determining the difference between each of the DC currents and the calibration current to produce a plurality of differences; and injecting each of the differences into a respective differential signal leg. By applying the differences to the signal legs, the DC offsets may be quickly corrected in a one-shot manner, rather than in successive approximations, which require multiple iterations of adjusting a compensating DC current to finally arrive at a desire DC offset correction.
In accordance with a further aspect of the approach, a computer-readable medium, embodying a set of instructions executable by one or more processors, includes code for determining a plurality of DC currents, the DC currents respectively associated with a plurality of differential signal legs in a transmission path; code for selecting a calibration current; code for determining the difference between each of the DC currents and the calibration current to produce a plurality of differences; and code for injecting each of the differences into a respective differential signal leg.
In accordance with a yet another aspect of the approach, an apparatus includes means for providing digital representations of a plurality of DC currents associated, respectively, with a plurality of differential signal legs; means for receive for producing instructions to generate compensating currents for the plurality of differential signal legs based on comparisons, respectively, between each of the digital representations and a calibration current; and means for injecting the compensating currents into the differential signal legs, respectively, to reduce DC offset between the differential signal legs, based upon the instructions.
Other systems, methods, aspects, features, embodiments and advantages of the improved DC offset reduction technique disclosed herein will be, or will become, apparent to one having ordinary skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, aspects, features, embodiments and advantages be included within this description, and be within the scope of the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
It is to be understood that the drawings are solely for purpose of illustration. Furthermore, the components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the apparatus and methods disclosed herein. In the figures, like reference numerals designate corresponding parts throughout the different views.
FIG. 1 is a block diagram of a DC offset correction loop for a differential signal as it may be implemented in a transmitter.
FIG. 2 is a block diagram illustrating an exemplary implementation of a plurality of DC offset correction loops in a transmitter.
FIG. 3 is a flow chart illustrating a method of operating a plurality of DC offset correction loops, for example, the DC offset correction loops of FIG. 2 .
DETAILED DESCRIPTION
The following detailed description, which references to and incorporates the drawings, describes and illustrates one or more specific embodiments. These embodiments, offered not to limit but only to exemplify and teach, are shown and described in sufficient detail to enable those skilled in the art to practice what is claimed. Thus, for the sake of brevity, the description may omit certain information known to those of skill in the art.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment or variant described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or variants. All of the embodiments and variants described in this description are exemplary embodiments and variants provided to enable persons skilled in the art to make and use the invention, and not necessarily to limit the scope of legal protection afforded the appended claims.
FIG. 1 shows a block diagram of transmitter components, including a DC offset correction loop 100 . During an operation in which the transmitter might operate without DC offset correction, a baseband current supply 102 may provide a differential signal leg on line 101 to a mixer 104 through a switch 106 . Mixer 104 may combine the differential signal leg with the output of an oscillator 108 , and provide the resulting signal to one or more amplifiers 110 to be transmitter through antenna 112 . In an alternative configuration of the loop 100 , the switch 106 may be omitted and its functionality instead implemented by selectively turning off the mixer gate 104 . As is known to those skilled in the art, the baseband current supply 102 may supply a differential signal leg such as, but not limited to, a quadrature signal leg, such as but not limited to Ip, Im, Qp, and Qm, which may be supplied for and included in a plurality of transmission paths.
During a normal operation in which DC offset correction is provided, switches 114 and 116 may be operated according to allow a programmable current source 118 and a programmable current sink 120 to provide and subtract, respectively, a compensating current to reduce DC offsets in the differential signal leg. Alternatively, the switches 114 and 116 may be omitted and their functionality instead implemented by selectively turning off the programmable current source 118 and current sink 120 . The programmable current source 118 and current sink 120 may be implemented using digital-to-analog converters (DACs). The various components may be energized through a power source 122 . The compensating current may be introduced at a current injection point 124 resulting in a DC offset corrected signal leg on line 103 . Such undesired DC offsets may be introduced to the differential signal leg through the baseband current supply 102 . For example, such DC offsets may be introduced into the differential signal leg through the operation of one or more current digital-to-analog converters represented by with the baseband current supply 102 , and/or through the operation of one or more baseband filters represented the by baseband current supply 102 .
During a calibration operation, switches 106 , 114 , and 116 may be opened, while calibration switches 126 and 128 are closed. During the calibration operation, the DC currents associated with the differential signal leg may be read through the operation of a resistor array 130 , an analog to digital converter 132 , and a digital engine 134 . The digital engine 134 may be designed and operated according to operate the programmable current source 118 , programmable current sink 120 , and switches 114 and 116 . The programmable current source 118 , programmable current sink 120 , and switches 114 and 116 may be collectively referred to as a DC offset current supply 136 . The digital engine 134 may provide operating instructions to the DC offset current supply 136 by introducing programming bits on line 138 to result in the introduction of the compensating current during the normal operation at current injection point 124 .
The digital engine 134 may be implemented in hardware, software, firmware or any suitable combination of the foregoing. For example, the digital engine 134 may be implemented, at least in part, with one or more general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), intellectual property (IP) cores or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
FIG. 2 shows a block diagram of transmitter components illustrating an exemplary implementation of a plurality of DC offset correction loops in a transmitter. Each of the DC offset loops may be based on the DC offset correction loop 100 illustrated in FIG. 1 . FIG. 2 shows a baseband block 202 that includes a plurality of baseband current supplies, for example the four baseband current supplies 102 a , 102 b , 102 c , and 102 d . The baseband current supplies 102 a - d may include, respectively, one or more baseband filters and/or current digital-to-analog converters corresponding to each differential signal leg. The baseband block 202 provides differential signal legs that may represent quadrature signal legs, such as, but not limited to, Ip, Im, Qp, and Qm, on lines 101 a , 101 b , 101 c and 101 d , respectively.
An offset current supply block 204 includes a plurality of programmable offset current supplies, for example, offset current supplies 136 a , 136 b , 136 c , and 136 d . The offset current block 204 provides a plurality of compensation currents to be combined with the plurality of differential signal legs, respectively, from baseband current supplies 102 a , 102 b , 102 c , and 102 d , at a plurality of current injection points, for example, current injection points 124 a , 124 b , 124 c , and 124 d.
A multiplexer 206 receives the DC offset corrected signal legs, processes the corrected signal legs, and produces a resulting multiplexed signal on line 208 . The programming bits introduced by digital engine 134 that were considered in regard to FIG. 1 , may include a first set of programming bits to supply a bias current on line 138 a to the offset current supply block 204 , and a second set of programming bits to provide operating instructions on line 138 b to the DC offset current supplies 136 a , 136 b , 136 c, and 136 d . The multiplexer 206 may also include a plurality of switches (not illustrated in FIG. 2 ) to perform the functions associated with switches 126 and 128 illustrated in FIG. 1 . Digital engine 134 may provide instructions to the multiplexer 206 switches through line 210 .
The resistor array 130 is connected between the power source 122 and line 208 . In an alternative configuration (not shown), four resistor arrays may be included, each connected between the power source 122 and a respective injection point 124 a - d and controlled by the digital engine 134 .
The transmitter components of FIGS. 1 and 2 may be included in a wireless communication device (WCD) that communicates with a plurality of base stations (not shown), preferably using a CDMA (code division multiple access) scheme or a W-CDMA (wideband CDMA) scheme.
FIG. 3 shows a flow chart illustrating a method 300 of operating a plurality of DC offset correction loops, for example, the DC offset correction loops illustrated in FIG. 2 . The method 300 may be performed by the digital engine 134 , controlling various components shown in FIG. 2 . The method 300 may begin, or be called to operate, with block 302 .
In block 304 , a plurality of uncorrected currents are read and stored, for example currents I 1 , I 2 , I 3 , . . . , I n . Currents I 1 , I 2 , I 3 , . . . , I n may represent currents on quadrature signal legs, such as, but not limited to, Ip, Im, Qp, and Qm, which may represent such quadrature signal legs for more than one transmission path. The plurality of uncorrected currents may be read by selectively closing calibration switches 126 and 128 while selectively opening switch 106 in each correction loop, and using analog-to-digital converter 132 to read the voltage produced across resistor array 130 for each loop, as a plurality of uncorrected currents are provided by baseband block 202 . Block 304 may also include sub-steps such as adjusting a gain of the current digital-to-analog converter associated with baseband current supply 102 , adjusting a gain of the baseband filter associated with baseband current supply 102 , and adjusting the bandwidth of the baseband filter, for the plurality of uncorrected currents.
In block 306 , a calibration current is selected. In one implementation, the calibration current is selected to be equal to the first of the plurality of uncorrected currents, for example I 1 where, for example, I 1 may be the uncorrected current on differential signal leg Ip. However, those skilled in the art will recognize that a variety of calibration currents may be selected, including, but not limited to currents associated with any of the other uncorrected currents, predetermined signals, signals of known amplitude, sinusoids of known amplitude, and modulated signals of known amplitude.
In block 308 , a determination is made as to whether all of the measured, uncorrected currents are within a range in which DC offset correction may be beneficially performed without degrading the signal legs. In one exemplary implementation, the current range may be between 1 micro-amp and 250 micro-amps. If all uncorrected currents are not within the range in which DC offset correction may be beneficially performed, the method 300 terminates in block 310 . If all uncorrected currents are within a range in which DC offset correction may be beneficially performed, the method 300 proceeds to block 312 .
In block 312 , the difference between the calibration current, for example I 1 , and one of the uncorrected currents is determined. Where the first uncorrected current is selected as the calibration current, the result may be zero for the first current.
In block 314 , a determination is made whether the result of block 312 is less than a predetermined tolerance current. If the result of block 312 is less than the tolerance current, the method 300 proceeds to block 316 and the processing for the present signal leg is terminated. If the result of block 312 is greater than the tolerance current, the method 300 moves to block 318 and the result of block 312 is divided by the least significant bit current. The least significant bit current may be set as the resolution of analog-to-digital converter 132 .
In block 320 , the result of block 318 may be entered in storage registers. For example, in registers associated with programmable current source 118 , programmable current sink 120 , and/or the current digital-to-analog converter (not shown) associated with the present signal leg.
In block 322 , a determination is made as to whether additional signal legs remain to be processed. If additional uncorrected signal leg currents remain to be processed, the next uncorrected current is selected and the method 300 returns to block 312 . For example, if the first current processed through blocks 312 through 320 was I 1 , the method 300 may next select current I 2 in block 324 and begin processing current I 2 in block 312 . The method 300 may proceed with processing uncorrected currents through blocks 312 through 320 until the plurality of uncorrected currents, I 1 , I 2 , I 3 , . . . I n , are processed. When it is determined in block 322 that all uncorrected currents have been processed, the method 300 terminates in block 326 .
In the method 300 , the DC currents associated with each of the plurality of uncorrected currents may be sequentially converted to voltages using resistor array 130 and read by analog-to-digital converter 132 . Codes corresponding to the voltages may be stored in digital engine 134 . The code associated with the first of the plurality of uncorrected currents may be used as a reference calibration code. An algebraic subtraction may be performed between each of the voltage codes and the reference calibration code. The differences (positive or negative) between the uncorrected voltage codes and the reference code may then be used to program, respectively, each of the offset current supplies 136 a - d to produce and inject compensation currents, respectively, into the uncorrected signal legs to correct the DC offsets between the signal legs. The above process of determining and applying the differences between the voltage codes and the reference calibration code represents a one-shot search approach to DC offset correction of signal legs, which approach significantly reduces the calibration time. Using this one-shot search approach, differential signal legs on a transmission path can be quickly balanced with respect, to one another in order to improve the performance of a digital transmitter.
The functionality, operations and architecture depicted by the blocks of method 300 may be implemented using modules, segments, and/or portions of software and/or firmware code. The modules, segments, and/or portions of code include one or more executable instructions for implementing the specified logical functions). In some implementations, the functions noted in the blocks may occur in a different order than that shown in FIG. 3 . For example, two blocks shown in succession in FIG. 3 may be executed concurrently or the blocks may sometimes be executed in another order, depending upon the functionality involved.
Among the advantages of the method and apparatuses disclosed herein is that they require minimal additional circuitry beyond that in some known transmitters and they require only a small additional die area in modern CMOS processes. For example, method 300 may require only components such as resistor array 130 , current source 118 , current sink 120 , and switches 106 , 114 , 116 , 126 , and 128 , beyond those components provided in some known transmitters. In addition, the DC offset correction techniques disclosed herein are relatively fast, as the conversion time roughly corresponds to n times the analog-to-digital conversion time, for example the conversion time required by analog-to-digital converter 132 , where n is the number of signal legs to be corrected. For example, for an analog-to-digital conversion time of 20 micro-seconds, the analog-to-digital measurement time associated with quadrature signals on two paths may 160 micro-seconds (8×20 micro-seconds). Digital operations that may be performed in method 300 , such as subtraction and programming of registers may be less than 10 micro-seconds.
A plurality of calibration signal types may be used with the DC offset correction loops and method 300 . The calibration signal types may be selectively provided by the baseband current supplies 102 , 102 a - d . For example, a first type may be a DC current of a designated amplitude, a second type may be a sinusoid of a designated amplitude, and a third type may be a modulated signal of a designated amplitude that correlates to the differential signal leg. The DC current of a designated amplitude may be the simplest manner of correcting DC offsets, and may be employed without using a look-up table. However, the DC current of a designated amplitude may not take into account variations between the current digital-to-analog converter and baseband filter gains.
The sinusoid of a designated amplitude may include operating range offsets for the current digital-to-analog converter and baseband filter gains. The sinusoid of a designated amplitude may be more accurate since some AC parasitic components may be accounted for. The sinusoid of a designated amplitude may require precisely syncing the sampling time of the sinusoid of a designated amplitude with the differential signal legs to avoid phase differences. However, since the resulting signal may vary from a sinusoidal signal, offset adjustments may be over-corrected or under-corrected depending upon the differences between differential signal legs.
The modulated signal of a designated amplitude that correlates to the differential signal leg may be the most accurate since the transmitter operation relative weighting of various codes may be better represented. The modulated signal of a designated amplitude that correlates to the differential signal leg may allow for adjustments based upon the typical resulting multiplexed signal and its peak-to-average ratio. The modulated signal of a designated amplitude that correlates to the differential signal leg may use the average of the resulting multiplexed signal over a period of time.
The DC offset in the differential signal legs may vary between the bits generated from the current digital-to-analog converter and between the various gain settings of the baseband filter. Additional correction steps incorporated into the method 300 and used with DC offset correction loops described herein may include selecting a current and gain setting that may best represent the expected differential signal leg. For example, a current and gain setting may be selected based on the expected minimum peak, the expected average, and the expected maximum peak, while performing DC offset correction for the selected current and gain setting. Non-selected current and gain settings may have similar, but slightly varying DC offsets.
Other correction steps incorporated into the method 300 and used with DC offset correction loops described herein may also include performing offset calculations for various current digital-to-analog converter settings and baseband filter settings and storing the results in a look-up table that may be incorporated into the digital engine 134 . Currents corresponding to the various gain settings may be measured and a DC offset correction may then be stored, for example in the digital engine 134 and/or the baseband current supply 102 , and/or a communication processing chip (not shown).
The DC offset correction techniques described herein may employ fast analog-to-digital converters, for example, where analog-to-digital converter 134 is a flash analog-to-digital converter 134 . In some implementations, the DC offset current supply 136 may be eliminated by various current digital-to-analog converter settings and baseband filter settings and storing the results in a look-up table.
In some configurations, the DC correction loops of FIGS. 1 and 2 and the method 300 are included in a mobile station modem (MSM) chip capable of controlling overall operation of a wireless communication device, such as a cellular phone, personal digital assistant (PDA), a satellite telephone, a portable computer, or any of a variety of devices capable of wireless communication.
In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as instructions or code on one or more computer-readable media. Computer-readable medium includes both computer storage medium and communication medium, including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable medium can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable medium.
The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use that which is defined by the appended claims. The following claims are not intended to be limited to the disclosed embodiments. Other embodiments and modifications will readily occur to those of ordinary skill in the art in view of these teachings. Therefore, the following claims are intended to cover all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. | Techniques for reducing or eliminating DC (direct current) offset in transmitters are disclosed. An apparatus for DC offset reduction may include a converter, a digital engine, and a plurality of programmable current supplies. The converter is configured to provide digital representations of a plurality of DC currents associated, respectively, with a plurality of differential signal legs. The digital engine is configured to receive the digital representations and to produce instructions for generating compensating currents for the plurality of differential signal legs based on comparisons, respectively, between each of the digital representations and a calibration current. The programmable current supplies correspond, respectively, to the differential signal legs. The current supplies are configured to inject the compensating currents into the differential signal legs, respectively, to reduce DC offset between the differential signal legs, based upon the instructions. The instructions allow one-shot DC offset correction, instead of successive approximation for DC offset correction. | 7 |
FIELD OF THE INVENTION
The present invention relates to agricultural sprayers, and more specifically relates to a valve coupler arrangement for facilitating the transfer of fluid from a nurse tank to the sprayer.
BACKGROUND OF THE INVENTION
It has recently become known to equip a sprayer vehicle and a nurse tank vehicle with a fluid coupler arrangement by which a fluid transfer conduit extending from the nurse tank can be manually or automatically connected to an intake fluid conduit leading to a sprayer tank. After making the connection, the operator opens a series of valves to establish a fluid path permitting fluid to flow from the nurse vehicle tank to the sprayer vehicle tank or tanks. Such a coupling arrangement is described in U.S. patent application Ser. No, 10/284,002, flied 30 Oct. 2002 and published under No, 200400484551, and now issued as U.S. Pat. No. 7,503,510, granted Mar. 17, 2004.
After the fluid tank or tanks of the sprayer vehicle have been refilled, the operator must close valves and disconnect the fluid coupler interconnecting the transfer and intake conduits in a manner which prevents or limits fluid chemicals from spilling onto the ground. One drawback of current large fittings and valves that are required for quickly transferring fluid chemicals from the nurse tank to the sprayer tank or tanks is that they permit significant spillage of the chemicals.
The problem to be solved then is to provide a coupler arrangement between the transfer and intake conduits of the nurse and sprayer vehicles which permits a relatively quick transfer of fluid chemicals while minimizing spillage of such chemicals.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a coupler arrangement for selectively connecting a nurse tank fluid transfer conduit to, and disconnecting the transfer hose from, a sprayer fluid intake conduit.
An object of the invention is to provide a coupler arrangement including a first coupler section connected to an end of a nurse tank fluid transfer conduit, and a second coupler section connected to an end of fluid intake conduit of a sprayer, with the first and second coupler sections being designed for cooperating, during being coupled together and uncoupled from each other, so as to eliminate any significant spillage of fluid chemicals.
The foregoing object is achieved by a coupler arrangement wherein the first and second coupler sections each include a hollow body defining a fluid passage, with the fluid passage of the first coupler section including a discharge opening normally closed by a first flow control valve such as a first poppet valve, which is spring loaded, and with the fluid passage of the second coupling section including an inlet opening normally closed by a second flow control valve such as a second poppet valve which is loaded to its closed position by the spring acting on the first poppet valve when a cylindrical insert defined at the end of one of the first and second coupler sections is seated within a cylindrical receptacle defined at the end of another of the first and second coupler sections, with a remotely operable power actuator being located within the hollow body of the second coupler section and connected to the second poppet valve so that the actuator can be selectively operated to open the first and second poppet valves against the spring load. The coupler section which defines the insert includes an annular seal groove containing an inflatable seal which may be selectively inflated for preventing leakage and establishing a tight friction lock between the insert and the receptacle once the insert is property seated in the receptacle. A proximity device is provided which senses when the insert is properly located in the receptacle and sends a signal to the operator prior to the inflation of the seal. Once the seal is inflated, the actuator is actuated for effecting the opening of both poppet valves so as to establish an uninterrupted fluid path through which fluid can flow from the nurse vehicle to the sprayer vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing a nurse vehicle fluid discharge conduit coupled to a sprayer vehicle inlet conduit over a releasable coupler arrangement.
FIG. 2 is a side view of the coupler arrangement with the coupler sections being shown in a separated condition.
FIG. 3 is a vertical, longitudinal sectional view of the coupler arrangement shown in FIG. 2 .
FIG. 4 is a view like FIG. 3 , but showing the coupler sections seated together, with the poppet valves closed.
FIG. 5 is a view like FIG. 4 , but showing the poppet valves opened.
FIG. 6 is a schematic representation of an electro-hydraulic control circuit for controlling the opening of the poppet valves incorporated in the coupler arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 , there is shown a self-propelled sprayer vehicle 10 positioned adjacent a nurse vehicle 40 during a refill operation. The sprayer vehicle 10 includes a frame 12 supported on front and rear pairs of ground wheels 14 and 16 , respectively. Mounted on a central region between opposite ends of the frame is an operator's cab 18 which contains all of the controls (not shown) for controlling the operation of the sprayer vehicle 10 including the routing of fluid to spray nozzles of a spray boom 20 supported at a rear end of the frame 12 . Fluid to be sprayed on a crop and/or the ground is contained in a tank 22 mounted on the frame 12 behind the cab 18 , with it to be understood that the tank 22 is merely representative and that a plurality of sprayer tanks could be provided. A fluid level sensor 23 is provided on the tank 22 for monitoring the level to which the tank is filled. A fluid intake conduit 24 is coupled for filling the tank 22 , and located in the conduit is a variable speed, high capacity, variable displacement load or transfer pump 26 serving for refilling the sprayer tank 22 . A separate pump (not shown) is provided for drawing fluid from the tank 22 and supplying this fluid to the spray boom 20 .
In order to maximize the operation of the load pump 26 for each of different plumbing configurations that typically might be encountered when refilling from different nurse tanks, the operation of the pump 26 is monitored. Specifically, the operation of the load pump 26 is monitored by a tachometer 28 coupled to the pump drive shaft, a flow detector 30 located at the output of the pump, a vacuum detector 32 located at the input of the pump and an accelerometer 33 coupled to a housing location of the pump for sensing pump vibration. All of the sensed or monitored pump conditions provide information to an automatic control arrangement and/or to a visual display so that the control arrangement may automatically operate or the operator may intervene to reduce the displacement of the pump 26 in the event that the sensed or monitored pump conditions indicate an impending pump cavitation condition. Of course, pump displacement may be increased when no impending cavitation condition is monitored.
The nurse vehicle 40 may be of any variety of known configurations, but is here shown in the form of a trailer having front and rear sets of ground wheels 42 and 44 , respectively, which are normally interconnected by a framework, not shown, which supports a trailer bed 46 on which is positioned a large nurse tank 48 , which in many cases would contain a supply of water, and a smaller nurse tank 50 which would contain a concentrated chemical for being mixed with the water, for example. A fluid transfer conduit 52 is coupled directly to the nurse tank 48 and is coupled to the smaller nurse tank 50 by a branch conduit 54 . The fluid transfer conduit 52 contains a first flow meter 56 located just downstream from the larger nurse tank 48 , while a second flow meter 58 is located in the branch conduit 54 , with the flow meters 56 and 58 acting to ensure that a correct mixture of the fluids from the tanks 48 and 50 is transferred to the sprayer vehicle tank 22 .
As illustrated, the fluid intake conduit 24 of the sprayer spray vehicle 10 and the fluid transfer conduit 52 of the nurse vehicle 40 are interconnected by a coupler assembly 60 including first and second separable coupler components, namely a receptacle indicated generally at 62 and an insert indicated generally at 64 . With reference to fluid flowing in a direction from the fluid transfer conduit 52 to the fluid intake conduit 24 , the receptacle 62 is connected to a downstream end of the transfer conduit 52 while the insert 64 is connected to an upstream end of the intake conduit 24 . Appropriate on-off valves (not shown) would be provided for respectively isolating the insert 64 from a remaining portion of the intake conduit 24 , and isolating the receptacle 62 from a remaining portion of the transfer conduit 52 when the coupler arrangement 60 is separated.
As can be seen in FIGS. 2-5 , receptacle 62 comprises a generally cylindrical body 66 defining a flow passageway 68 there through. The body 66 comprises a flange 70 having an axially facing, annular mounting face 72 clamped, as by bolts 74 , against a similar mounting face 76 defined by a flange 78 of a funnel-shaped body extension 80 having its smaller end received in and secured to the transfer conduit 52 . The downstream end of the body 66 comprises an axially extending annular wall 82 having a cylindrical inner surface 84 joined to a radially extending annular surface 86 so as to define a receptacle for receiving an end of the insert 64 .
The receptacle 62 further includes a poppet valve 90 for sealing the flow passageway 68 . Poppet valve 90 includes a stem 92 joined to a head 94 having a periphery defining a sealing surface including a leading cylindrical/pilot section 96 joined to a small diameter end of a frusto-conical section 98 , with an o-ring seal 100 being located in a seal groove provided at a juncture of the two sections. The stem 92 is mounted for sliding axially within a bushing carried by a support member 102 fixed within the receptacle body 66 . A coil compression spring 104 is received on the poppet valve stem 92 and acts between the support member 102 and the head 94 so as to normally bias the sealing surface of the poppet valve head 94 against a mating valve seat 106 at a discharge end of the passageway 68 . An axial end face 108 of the poppet valve head 94 is a concave surface formed as a spherical segment and has an outer periphery which is substantially coplanar with the receptacle surface 86 when the poppet valve 90 is closed, as shown in FIG. 4 .
The insert 64 includes a generally cylindrical body 110 defining a flow passageway 112 there through. A downstream end region of the body 110 is defined by a mounting flange 114 having an axially facing mounting surface 116 on its downstream end disposed in confronting relationship to a mounting surface 118 of a mounting flange 120 located on the upstream end of an elongate, cylindrical body extension 122 including a downstream end section which is reduced in diameter and connected to the intake conduit 24 . A circular support plate 124 has an outer annular region clamped between the flanges 114 and 120 by a plurality of screws 125 extending through axially aligned holes provided in the flange 120 and plate 124 and received in threaded holes provided in the flange 114 . The support plate 124 is provided with a plurality of openings (not shown) for permitting the free flow of fluid from the downstream end of the passageway 112 . The upstream end of the insert body 110 is defined by an annular plate 126 fixed to a remainder of the body 110 by a plurality of screws 128 . The plate 126 cooperates with a reduced diameter portion of the body 110 to define an annular seal groove 130 , with an inflatable seal 132 being received in the seal groove 130 . An air fitting 134 is provided on the flange 114 of the insert body 110 and leads to air passage 136 which extends to the inflatable seal 132 . A cylindrical shoulder 138 is provided between the seal groove 130 and the flange 114 and is sized to fit snuggly within the cylindrical wall 82 of the receptacle body 66 when the insert body 110 is received in the receptacle of the receptacle body 66 , as shown in FIGS. 4 and 5 . When so received, the insert 64 may be locked within the receptacle 62 by inflating the seal 132 by connecting a source of air pressure 133 to the fitting 134 . So as to insure that the insert body 110 is received in the receptacle of the receptacle body 66 prior to the seal 132 being inflated, a proximity sensor or sensors 139 is (are) provided in the flange 114 in axial alignment with an end face of the wall 82 , with the sensor(s) 139 generating a signal when the insert body 110 is properly received in the receptacle body 66 .
The insert 64 further includes a poppet valve 140 for sealing flow through the flow passageway 112 and a remotely controlled poppet valve actuator 142 is provided for selectively opening and closing the poppet valve. The valve actuator 142 comprises a single-acting, extensible and retractable air cylinder 144 (alternatively a hydraulic or electric actuator could be) disposed along a central axis of the body extension 122 and having a threaded tube 146 fixed to an upstream end cap, the tube 146 projecting through a hole provided centrally in the support plate 124 and receiving a nut 148 which is tightened against the plate 124 so as to fix the cylinder 144 to the support plate 124 . The poppet valve 140 comprises a stem defined by a piston rod 150 of the air cylinder 144 , and a head 152 screwed onto a threaded end of the piston rod. As considered relative to moving from an open position, illustrated in FIG. 5 , to a closed position, illustrated in FIGS. 2 and 3 , an outer periphery of the poppet valve head 152 defines a sealing surface including a leading cylindrical pilot section 154 followed by a frusto-conical section 156 . A seal groove containing an o-ring seal 158 is located at the juncture of the two sections 154 and 156 . The inlet end region of the flow passageway 112 is defined by a valve seat 160 configured to mate with the sealing surface of the valve head 152 . A coil compression spring 161 is received about the piston rod 150 internally of the air cylinder 144 and acts against a piston secured to the rod 150 so that a biasing force acts on the poppet valve head 152 in a direction tending to seat the sealing surface 156 against the valve seat 160 so as to prevent spillage when the coupling 60 is separated. Spillage of fluid when the coupling 60 is separated is also reduced by providing the valve head 152 with an axial face 162 in the form of a convex segment of a sphere sized to mate with the concave axial face 108 of the valve head 94 so that no fluid is trapped between the valve heads 94 and 152 that would escape when the coupling 60 is separated. It is to be noted that the shape of the axial faces of the valve heads 94 and 152 permits the heads to be slightly misaligned without affecting their tight engagement with one another. Also, it is to be noted that the valve head 94 of the poppet valve 90 associated with the receptacle 62 has a minor diameter which is just slightly larger than a major diameter of the valve head 152 of the poppet valve 140 associated with the insert 64 and that, when the poppet valves 90 and 140 are open, the distance between the circumference of the valve heads 94 and 152 , and a frusto-conical inner wall surface region of the receptacle body 66 is substantially constant so that a smooth flow occurs around the open valve heads.
An air supply/return conduit 164 is located within the insert body extension 122 and has opposite ends respectively coupled to an L-fitting 166 located adjacent one end of the cylinder 144 and a straight air fitting 168 extending through an end region of the insert body extension 122 adjacent the intake conduit 24 . Located at an opposite end of the cylinder 144 from the fitting 166 is another fitting (not shown) which is coupled to an air line leading to atmosphere for permitting the exhaust and intake of air during extension and retraction of the piston rod 150 so that an air lock preventing free movement of the piston rod does not occur. It will be appreciated that the source of air pressure 133 can be selectively coupled to an air line 180 (shown only in FIG. 6 ) joined to the straight air fitting 168 in order to effect extension of the piston rod 150 and simultaneous movement of the poppet valve heads 94 and 152 from their seated closed positions, shown in FIG. 4 , wherein fluid flow through the passage ways 68 and 112 is prevented, to their open positions shown in FIG. 5 , wherein a continuous flow path is provided from the transfer conduit 52 to the intake conduit 24 by way of the flow passageways 68 and 112 .
Referring now to FIG. 6 , there is shown a representative electro-pneumatic circuit 170 for controlling the operation of the pneumatic actuator 142 for controlling the opening and closing of the poppet valves 90 and 140 . It is to be noted that since the self-propelled sprayer vehicle 10 has an electric power supply, such as a battery, all of the powered components or elements of the coupler arrangement 60 are associated with the insert 64 so as not to require further coupler elements between the nurse tank vehicle and the sprayer vehicle.
The control circuit 170 includes an electronic controller 172 to which is connected the tank level sensor 23 , the proximity sensor(s) 139 and an indicator device 174 , such as a display device located in the sprayer vehicle cab 18 . An operator input device 175 , which may include an activation switch, for example, is provided by which the operator can send a start signal for initially arming the controller 172 for the automatic filling operation, with automatic filling beginning once a signal is received from the proximity sensor(s) indicating that the coupler assembly 60 is coupled. Also coupled to the controller 172 is an on board air system 176 including the source of air pressure 133 coupled to first and second electrically responsive control valves here depicted as solenoid valves 190 and 192 , respectively, for selectively either controlling the flow of air from the source of air pressure 133 to the inflatable seal 132 by way of an air supply line 178 , and to the pneumatic actuator 142 by way of the air supply line 180 . Additionally, the controller 172 is connected to an electrically responsive displacement control valve arrangement 182 , which, in turn is coupled to a displacement controller 184 of the variable displacement load pump 26 . The pump condition monitoring components, specifically the tachometer 28 , flow detector 30 , vacuum detector 32 , and accelerometer 33 are designated collectively as a pump condition monitoring arrangement 186 that is likewise coupled to the controller 172 , with it to be understood that respective pump condition signals are generated by each of the components. Further, it is to be noted that not all of the condition monitoring components are required for acquiring sufficient information for a determination of impending pump cavitation.
Assuming an operator is performing a spraying operation, the operator will become aware of the need to refill the tank 22 by a signal sent by the fluid level sensor 23 which is sent to the indicator device 174 at the operators station. The operator will then shut down the sprayer pump and drive the sprayer vehicle 10 to the staging area where the nurse tank vehicle 40 has been previously parked for refilling the sprayer tank 22 .
The operator will then arm the controller 172 for performing an automatic fill operation by hitting the activation switch of the input device 175 . The operator then takes steps to bring the coupler insert 62 and receptacle 64 of the coupler assembly 60 into axial alignment with each other and to move them together, with the insert 62 being located within the receptacle 64 . Upon the insert 62 becoming completely received in the receptacle 64 , the proximity sensor(s) 139 will send a coupled signal to a sequencing logic arrangement of the controller 172 so as to initiate the automatic fill operation. The sequencing logic circuit first acts to send a lock signal to a first solenoid-operated air valve 190 of the onboard air system 176 for causing the air valve to shift so that the source of air pressure 133 is automatically routed for effecting inflation of the seal 132 , thereby locking the coupler insert 62 and the receptacle 64 together. Following this, the sequencing logic circuit within the controller 172 sends an open signal to a second solenoid-operated air control valve 192 of the onboard air system 176 for causing the air valve to shift so that the source of air pressure 133 is automatically routed for effecting extension of the pneumatic actuator 142 , and, thus, opening of the poppet valves 90 and 140 . The sequencing logic contained in the controller 172 then acts to send a signal for actuating the appropriate solenoid of the electrically responsive displacement control valve arrangement 182 for causing the latter to control the flow of hydraulic fluid to the displacement controller 184 of the pump 26 so as to ramp-up displacement of the pump 26 so that it begins to transfer fluid from the nurse vehicle 40 to the sprayer vehicle 10 .
Pump operation is monitored by the tachometer 28 , flow detector 30 , vacuum detector 32 and the accelerometer 33 , with these devices sending respective signals to the controller 172 . In the event that the monitored or sensed operating condition of the pump 26 indicates that cavitation is impending, the controller 172 will send a signal to the electrically responsive displacement control valve arrangement 182 for causing the latter to route a control fluid signal to the displacement controller 184 of the pump 26 to cause the displacement to be decreased sufficiently to avoid cavitation.
Upon the sprayer tank 22 becoming filled, the fluid level sensor 23 will send a full signal to the controller 172 which then sends a ramp-down signal to the electrically responsive displacement control valve arrangement 182 which sends a fluid control signal to the displacement controller 184 of the pump 26 to decrease its displacement to zero. Shortly thereafter, the sequencing logic section of the controller 172 will receive a close signal and will terminate the open signal previously sent to the second solenoid-operated air control valve 192 of the on board air system so as to effect the venting of the air from the air line 180 thus permitting the springs 161 and 104 to act to close the poppet valves 90 and 140 . Subsequently, the sequencing logic section of the controller 172 will receive an unlock signal and will terminate the lock signal previously sent to the first solenoid-operated air control valve 190 of the air system so as to vent the air from the inflatable seal 132 . The indicator device 174 at the operator station will also receive the unlock signal and display the fact that the insert 62 and receptacle 64 of the coupler arrangement 60 are no longer locked together. The refill operation is then completed and the operator can separate the insert 62 from the receptacle 64 and drive the sprayer 10 away from the nurse vehicle 40 and return to the field to resume the spraying operation.
Thus, it will be appreciated that once the operator arms the control system for automatic refill operation and the controller receives a signal from the proximity sensor(s) 139 indicating that the insert 62 and receptacle 64 of the coupler arrangement 60 are coupled together, the remainder of the refill operation is automatic with a substantially leak-free coupling being established prior to the opening of the poppet valves 90 and 140 . Further due to the poppet valve heads 94 and 152 being respectively biased against the valve seats 106 and 160 by the springs 104 and 161 , and due to the close fit of the valve head faces 108 and 162 with each other during flow through the coupler arrangement 60 , no fluid escapes around, and no fluid is trapped between the valve heads when the poppet valves close immediately after ramp-down of the pump 26 after the sprayer tank 22 is filled, thus eliminating any spillage from this area when the coupler arrangement 60 is separated.
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. | A nurse vehicle carries a supply of liquid chemicals or fertilizer for being applied by a sprayer vehicle. A fluid transfer conduit of the nurse vehicle has an end defined by a receptacle that is selectively connected to a complementary dimensioned insert defining an end of a fluid intake conduit of the sprayer vehicle. The receptacle and insert define a coupler assembly that includes an inflatable seal that surrounds the insert and locks the insert and receptacle together when inflated. Flow through the coupler assembly is controlled by first and second poppet valves, which are normally closed preventing flow through valve bodies of the receptacle and insert. Selective inflation of the seal and opening and closing of the poppet valves is automatically controlled in accordance with sequencing logic of an electronic controller so the seal is inflated before the valves are opened and remains inflated until the valves are closed. | 8 |
This is a continuation of application Ser. No. 899,608, filed Apr. 24, 1978 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a structure floating on a body of water. More particularly, the invention relates to a floating structure from which drilling wells and/or production of oil and gas or like operations, or both, are carried out. In its more specific aspects, the invention concerns a floating structure having buoyancy means to float the structure and in which the structure is anchored by a plurality of essentially parallel and vertical conduits commonly called "risers." More specifically, the invention concerns such a structure in which concentric casing strings, within riser pipes, form an important part of the anchoring system.
2. Setting
In recent years, it has become desirable to use a floating vessel from which to drill wells in marine locations. Many of these structures have been maintained on station by conventional spread catenary mooring lines, or by propulsion thruster units. One system of floating vessel receiving attention for drilling or production of wells in water is the Vertically Moored Platform, such as described in U.S. Pat. No. 3,648,638, issued Mar. 14, 1972, entitled "Vertically Moored Platform," Kenneth A. Blenkarn, inventor. A key feature of Vertically Moored Platforms is that the floating platform is connected to anchor means in the ocean floor only by elongated, parallel members which are preferred to be large diameter conduits, commonly called "riser pipes." These elongated members or riser pipes are held in tension by excess buoyancy of the platform.
3. Prior Art
This invention is an improvement over the anchoring system described in U.S. Pat. No. 3,648,638, supra. This patent is considered the closest prior art and, as stated above, our present invention is an improvement thereon. Other patents dealing with Vertically Moored Platforms include U.S. Pat. Nos. 3,559,410; 3,559,411; 3,572,272; 3,976,021; 3,978,804; 3,983,828; 3,993,273; 4,062,313; and 3,154,039. There are prior patents and art which teach to have concentric strings of casing extending from an underwater well to a platform above the water. In this latter regard, attention is directed to U.S. Pat. No. 3,971,576. U.S. Pat. No. 3,705,623 shows concentric pipes 33 and 17 connected to a buoyancy member 19; however, those concentric pipes form no part of the anchoring system. None of these patents or art to our knowledge teach to anchor a Vertically Moored Platform by means of concentric tensioned casing strings within an outer tensioned riser pipe. No prior art is known to do this.
BRIEF DESCRIPTION OF THE INVENTION
This invention concerns an anchoring system and method of connecting a vessel floating on a body of water to a subsea well having a first string of casing set and secured in a hole in the bottom of said body of water, and a second string of casing supported in the first string and extending deeper than said first string of casing and secured in said hole. A first riser conduit (commonly called a "riser pipe") is connected at its lower end to said first string of casing in a sealing relationship so that the first riser conduit and the first string of casing form a fluid-tight conduit. The upper end of said first riser conduit is supported from the vessel to apply a tension thereto. The lower end of a second riser conduit or riser casing is connected to the second string of casing in a sealing relationship so that said second string of casing and the second riser conduit form a second fluid-tight conduit. The upper end of the second riser conduit is supported from an upper portion of the first riser conduit such that a tension is applied to the second riser conduit when tension is applied to the first riser conduit.
The upper and lower ends of the first riser conduit (or riser pipe) are provided with terminators which are really stiffened sections of the riser pipe to distribute curvature over a length or a portion of the length of the riser pipe. The second or inner riser conduits are provided with centralizers within the outer or first riser conduit terminators. The upper and lower ends of the inner casing strings need no terminators.
Various objects and a better understanding of the invention can be had from the following description taken in conjunction with the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a Vertically Moored Platform.
FIG. 2 illustrates, partly in cutaway view, one riser pipe means of one leg of the Vertically Moored Platform of FIG. 1.
FIG. 3 illustrates an enlarged cross-sectional view of the means of FIG. 2 of connecting the top ends of the inner casing strings to the riser pipe.
FIG. 4 shows one means of connecting the riser pipe to the string of casing anchored in the wellbore.
DETAILED DESCRIPTION
Reference is first made to FIG. 1 which shows a side view of a Vertically Moored Platform. Shown therein is a platform 10 supported on a body of water 12 having a bottom 14. The structure 10 generally includes a float means 16 which supports a working deck 18 above the surface 20 of the body of water 12. It is to be noted that a Vertically Moored Platform is described in detail in prior U.S. Pat. No. 3,648,638, supra. Float means 16 is, for example, composed of four bottle-shaped buoyant legs 22. Each leg 22 is anchored by a plurality of riser pipes 24 which are provided with spacers 26. Riser pipes 24 connect to casings 28 which are cemented in holes in the bottom of the body of water. A template 30 is shown on the bottom 14 through which the wells for casings 28 were guided. Riser pipes 24 normally are made of high quality steel and typically are 20 inches in diameter. The riser pipes 24 are parallel and are held in tension by the vertical force exerted on the buoyant structure. The typical length of these riser pipes 24 may be from 500 feet up to several thousand feet from the base of the leg member 22 of the Vertically Moored Platform to the sea floor 14.
Attention is next directed to FIG. 2 which illustrates an improved anchoring connection means between the Vertically Moored Platform and the sea floor. Shown thereon is leg 22 which is one of the four float members of the Vertically Moored Platform of FIG. 1. For simplicity and ease of understanding, we have shown only one riser pipe means extending between the leg 22 and the sea bottom 14. A vertical passage 32 extends through the lower part or enlarged portion of leg 22. The upper end of riser pipe 24 is provided with an upper riser terminator 34. As a word of explanation, it is known that if a tubular member is held under tension and subject to bending, stresses concentrated in the ends. One way of meeting this problem is to make the end section sufficiently strong to distribute the bending deformation which may concentrate therein over a longer length. This is what is done here and we call the strengthened portion "a terminator," in this case, "the upper riser terminator 34." Thus, a terminator is a stiffened section of riser pipe to distribute curvature over a selected portion of the riser pipe.
Upper horizontal bearings 36 and lower horizontal bearings 38 are provided between upper terminator 34 and the wall of passage 32 through jacket 22. Above the horizontal bearing 36 is a vertical bearing means 40. Details of this vertical bearing 40 are shown in U.S. Pat. No. 3,976,021, FIGS. 17 and 18. It includes primarily a jack 42, bracket 44, engaging shoulders 46 of the upper end of the upper riser terminator 34, and shims and bearings 48. The vertical force of the tension in riser pipe 24 is transmitted through vertical bearing 40 to the Vertically Moored Platform jacket 22.
The lower end of riser pipe 24 is connected to a lower terminator 50 which passes through a drive pipe 52 in template 30. A 20-inch conductor casing 54 is hung from drive pipe 52 through mudline suspension 56, which in reality may be a upwardly facing shoulder 58 on drive pipe 52, and a shoulder 60 having a downwardly facing shoulder attached to the outer wall of 20-inch conductor casing 54. If the bottom 14 is sufficiently soft, drive pipe 52 can be driven the required depth into the bottom 14; otherwise, a hole can be drilled through the guide tube. A hole can be drilled through drive pipe 52 and the 20-inch conductor casing 54 set and cemented in place using conventional sea-drilling equipment.
After the 20-inch casing has been cemented in place, a smaller diameter hole to accommodate the next smaller size of casing can be drilled in the bottom thereof. This may be a 135/8 inch casing, which is illustrated as intermediate casing 62, which is supported by mudline suspension 64, which is similar to mudline suspension 56. The second or 135/8 inch intermediate casing 62 is then run and cemented in place. Then, the 135/8 intermediate riser conduit 78 is run and connected to casing 62. After this, an additional hole is drilled to accommodate the next smaller size of casing, which may be 95/8. The innermost casing 66 is run and cemented in place and is suspended by mudline suspension 68. Any desired number of casing strings may be set in place in drilled holes in a manner described above which is well known. The upper ends of each of casings 54, 62, and 66 are provided with a locking means, such as J-slots 70, 72, and 74.
The lower end of riser pipe 24 is connected to the upper end of conductor casing 54 by a J-lug 76 which fits into the J-slot 70. Sealing means are also provided so that a fluid-tight conduit is formed from the conductor casing 54 upwardly to the floating structure as exemplified by jacket 22. Latching means, not shown, between conductor casing 54 and drive pipe 52 can be installed to restrain vertical movement between conductor casing 54 and drive pipe 52. A similar device can be installed for succeeding pairs of casing strings such as casing 62 and 66.
Within riser pipe 24 are shown two concentric strings of casing, an intermediate riser conduit 78 and the innermost riser conduit 80. Of course, any reasonable number of inner casing strings can be used. The lowermost end of intermediate riser conduit 78 is connected through J-slot 72 to the cemented casing 62 in the borehole, and, likewise, the lower end of innermost riser conduit 80 is connected to the cemented innermost casing 66, which is shown as the smaller one in the drawing. Thus, we have a casing 62 and intermediate riser conduit 78 forming a fluid-tight conduit extending from the bottom of the casing to the top of the intermediate riser conduit 78; likewise, a smaller fluid-tight conduit is formed from the lower end of the innermost casing 66 through riser conduit 80 to the top of the platform. If desired, intermediate riser conduit 78 can be run before the hole for the inner casing 66 is drilled.
The connecting arrangement between the riser pipe and the casing set in the wellbore is shown in FIG. 4. Shown thereon also is the J-slot 70 on the upper end of the enlarged end portion of conduit casing 54 and a J-lug 76, which is on the lower end of riser 24. Seal means 82 are provided between the lower end of riser 24 and the enlarged portion of the upper end of conduit casing 54. Connection 72 for intermediate riser conduit 78 and cemented casing 62 and connection 74 for innermost riser conduit 80 and cemented casing 66 can be like that shown in FIG. 4.
Attention is now directed to means for supporting the upper end of intermediate riser conduit 78 and innermost riser conduit 80 to the upper end of the riser pipe such that the inner riser conduits 78 and 80 form a part of the anchoring system. This is shown clearly in FIG. 3. The upper end of riser pipe extension 24A is provided with a flange 81. A casing hanger spool 84 is provided to sit on top of flange 81. Means are provided to connect the casing hanger spool 84 to the intermediate riser conduit 78. This includes a slip means 86. Screw 88 is used to set a seal of the annulus between casing 78 and casing hanger spool 84. Thus, the upper end of intermediate riser conduit 78 is supported from riser extension 24A through casing hanger spool 84. Casing hanger spool 84 has an upper flange 92 which supports casing hanger spool 94; thus, innermost casing string 80 is supported from riser extension 24A through casing hanger spools 84 and 94. Bolts 100, 102, and 104 with proper machining and sealing are provided to assure fluid-tight annular spaces 106 between riser extension 24A and riser conduit 78 and annulus 108 between the two inner riser conduits 78 and 80. Plugs 110 and 112 may be removed and pressure gauges installed to determine the pressure in these annuli. Conventional valves and other equipment may be placed on extension 114 in which to produce the well drilled through these casings.
The preferred installation procedure is to first pre-tension the riser 24 to a predetermined value with the jack 42 and then shim it in place on bearing 48. The hole for the casing 62 is drilled. The casing 62 is run and cemented in. The intermediate riser conduit 78 is run and latched to intermediate 62 at the J-slot 72; then, the casing riser conduit 78 is tensioned with the draw work of the drilling rig to a predetermined value which is a function of the riser 24 tension. The locking means 86 is set, locking the upper end of intermediate riser conduit 78 to casing hanger spool 84. Other inner strings are installed in a similar manner.
Within riser 24 and riser terminators 34 and 50, we have provided centralizers 35 between the riser 24 and terminators 34 and 50 and the first or intermediate riser conduits 78 and centralizers 37 between riser conduits 78 and 80. By thus doing so, we control the frictional wear caused by the relative motion between the two strings. Also, the casing string, being inside the riser, does not require a terminator.
By the system that we have just described, a substantial part of the mooring is by the riser conduits 78 and 80. This provides a much stronger anchoring means for a given size of riser pipe and will afford more protection in the event of a very severe storm. The amount of mooring by the outer riser pipe 24 compared to the inner casing riser conduits 78, 80, etc., is a function of the cross-sectional area or, more accurately, a function of their respective axial flexibility. The part of the mooring carried by the riser conduits may vary from as low as about 25% to about 70% of the total mooring forces.
An example of where the riser conduits carry 27% of the mooring force in calm water is:
Riser (24): 185/8" OD 0.625" W.T., 610 kips
Riser Conduit (78): 95/8" OD 0.352" W.T., 128 kips
Riser Conduit (80): 7" OD 0.272" W.T., 72 kips
Tubing Riser: 27/8" OD 0.217" W.T., 23 kips
Note: A KIP is 1000 pounds.
An example of where the riser conduit carry 45% of the mooring force in calm water is:
Riser: 185/8" OD 0.625" W.T., 455 kips
Riser Conduit: 133/8" OD 0.380" W.T., 144 kips
Riser Conduit 95/8" OD 0.472" W.T., 126 kips
Riser Conduit: 7" OD 0.453" W.T., 86 kips
Tubing: 27/8" OD 0.276" W.T., 21 kips
An example of where the casing risers carry 60% of the mooring force in calm water is:
Riser: 185/8" OD 0.625" W.T., 460 kips
Riser Conduit: 133/8" OD 0.380" W.T., 208 kips
Riser Conduit: 95/8" OD 0.972" W.T., 239 kips
Conduit Riser: 7" OD 0.276" W.T., 194 kips
Tubing Riser: 2×23/8" OD 0.190" W.T., 45 kips
An example of where the casing risers carry 67% of the mooring force in calm water is:
Riser: 185/8" OD 0.625" W.T., 460 kips
Riser Conduit: 133/8" OD 0.719" W.T., 383 kips
Riser Conduit: 95/8" OD 0.545" W.T., 271 kips
Riser Conduit: 7" OD 0.54" W.T., 231 kips
Tubing Riser: 2×23/8" OD 0.218" W.T., 60 kips
These distributions are determined by the axial flexibility of the riser strings and by the expected temperature and pressure effect. They will change when the temperature and the pressure distribution between each string vary. They will also change when the total mooring force changes under the influence of the wind, the waves, and the current.
While the above embodiments have been described in great detail, it is possible to incorporate variations therein without departing from the spirit or scope of the invention. | An improved system for anchoring a floating vessel which is anchored only by parallel and essentially vertical conduits. The anchoring load is carried by units of concentric pipes including an outer riser pipe and inner strings of casing. Drilling wells and/or production of oil and gas or like operations are conducted through these casings. The tension of the inner casing string is transmitted to the floating vessel through the upper end of the outer riser pipe. The system prevents excessive buildup of stresses in the upper end of the inner casing due to the bending caused by excursions caused by the waves, the wind and the current. | 4 |
This application claims priority to German Patent Application Nos. 198 17 180.3-52 (filed Apr. 17, 1998 and issued Apr. 27, 2000 as German Patent No. DE 198 17 180) and 198 53 428.0 (filed Nov. 19, 1998), which are hereby incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
This invention relates to a biosensor (affinity sensor) in which a hydrogel, a surfactant layer or biotin is bonded to the sensor's precious metal surface by a short chain linker, and further relates to the procedure for the preparation thereof.
For signal generation, the surfaces of surface plasmon resonance (SPR) based affinity sensors must possess a precious metal layer, usually of gold, with a thickness of approx. 50 nm. However, direct bonding of receptors, typically proteins, to the precious metal surface has proven to be impractical because the receptors are easily denatured in this environment and as a result lose their receptor function. Also, bare sections of the precious metal surface can be subject to unspecific adsorption phenomena which seriously flaw the measurement results.
To avoid this problem, it is general practice to covalently bond to the precious metal surface a several nm thick dextran layer that swells in an aqueous medium to a thickness of approx. 100 nm and completely covers the precious metal surface. The swollen polymer layer mimics the natural environment of biomolecules and is thus suited to prevent the denaturation and the resulting inactivation of the receptors. The adsorption of molecules other than those to be analyzed is effectively suppressed. In addition, the swollen dextran layer is able to compensate surface irregularities: the bonding of receptor molecules occurs in the swollen matrix and not only immediately on the surface. This reduces the significance of surface roughness that would otherwise result in a poorly defined surface and thus in poorly quantifiable measurement results.
Coatings are known which can be applied to sensor surfaces to both prevent unspecific adsorption and to serve as a matrix for the receptor molecules (Molecular Resolution Imaging of Dextran Monolayers Immobilized on Silica by Atomic Force Microscopy, Langmuir, 1996, 12, 6436). However, such surfaces often possess defect sites resulting from their molecular structure and therefore do not provide sufficient protection against unspecific adsorption.
EP-B-589 867 describes a biosensor measuring surface in which a porous matrix, e.g. a hydrogel such as dextran, is bonded to a metal surface via a monolayer of organic molecules (linkers). Such coatings are used in the preparation of disposables for commercial SPR sensors. To ensure complete covering of the biosensor's surface with the porous matrix and sufficient stability, EP-B-589 867 specifies that molecules having a hydrocarbon chain with a length of more than 10 atoms be used as linkers. The linker's functional groups to which the porous matrix is bonded are hydroxyl, carboxyl, amino, aldehyde, hydrazide, carbonyl, expoxide or vinyl groups. The preferred linker is 16-mercaptohexadecanol, the hydroxyl group of which must by activated by a reaction using epichlorhydrin before the bonding of dextran to the sensor surface. EP-B-589 867 does not make any statements on the conditions of further reactions of the other functional groups with a porous matrix,
The necessity for using long-chained linkers to bond the porous matrix to the precious metal surface is a disadvantage, given the time and effort required to prepare such compounds. A further disadvantage is the use of the toxic and carcinogenic epichlorhydrin for the activation of the linker's functional group.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a biosensor with a modified precious metal surface in which a hydrogel, a surfactant layer or biotin is linked to the precious metal surface by less complex and, if possible, commercially available linker molecules.
A further object of the invention is to provide a process for the preparation of the above biosensor with a modified precious metal surface which is less expensive and easier to implement than the state-of-the-art procedures.
These aims could be accomplished owing to the finding that even with the use of linker Molecules having a hydrocarbon chain length of 10 atoms or less, a complete covering of the precious metal surface with a hydrogel, a surfactant layer or biotin can be achieved if the linker molecule monolayer is stabilized by hydrogen bonds, aromatic-aromatic interactions or covalent bonds.
The present invention thus refers to a biosensor the surface of which comprises a precious metal layer to which a hydrogel, a surfactant layer or biotin is bonded by means of a monolayer of organic molecules, whereby said employed organic molecules used for this have the formula A—R—B in which A is an atom or group providing the bonding to the precious metal; R is a branched or straight hydrocarbon chain with a chain length of 10 carbon atoms or less, whereby the hydrocarbon chain may be interrupted in up to two places each by a phenylene group or an heteroatom, and B is an atom or group providing the bonding to the hydrogel, the surfactant layer or the biotin.
The invention also provides a process for the preparation of the aforesaid biosensor in accordance with one of the claims 12 to 15 .
The inventive biosensors with a modified precious metal surface are preferably used for surface plasmon resonance (SPR) applications.
In order to prevent unspecific adsorption of receptor molecules, the surface of the biosensor must be completely covered with hydrogel, a surfactant layer or biotin. One prerequisite for a stable hydrogel, surfactant or biotin layer is sufficient stability of the linker molecule layer underneath. Such stability can be ensured by hydrogen bonds, by aromatic-aromatic interactions (π-π interactions) or by covalent bonds, which may be provided by an interlayer containing metal oxide. Such interactions or bonds occur between the linker molecules or between the linker molecules and the hydrogel, the surfactant or the biotin.
Hydrogen bonds may exist between amide bonds (e.g. B=amine group; carboxyl-functionalized hydrogel) or between hydroxide and carboxyl groups (e.g. B=epoxide group; carboxyl-functionalized hydrogel). In systems where hydrogen bonds exist, such hydrogen bonds may be formed between the linker modules and the hydrogel, the surfactant layer or the biotin, where they serve for bridging or preventing local defects.
Aromatic-aromatic interactions are observed between aromatic ring systems in the linker molecules. Such interactions are the source of attraction forces between the linker molecules which stabilize the monolayer. Suitable aromatic groups are phenylene groups, and in particular those phenylene groups that are incorporated in the linker molecule in para position. The phenylene groups may be substituted with small, non-bulky alkyl groups such as methyl or ethyl groups.
Another possibility to provide a stable linker molecule layer is the introduction of covalent bonds. In a preferred embodiment, the first step after bonding of a low molecular weight short-chained linker of the present invention is to build up, preferably by a sol-gel process, a dense interlayer comprising metal oxide (Stepwise Adsorption of Metal Alkoxides on Hydrolyzed Surfaces: A Surface Sol-Gel Process, Chemistry Letters, 1996, 831); which in a second step is linked to the hydrogel, the surfactant or the biotin by means of the hydroxide groups contained in it (Surface Modification for Direct Immunoprobes, Biosensors and Bioelectronics, 1996, 11, 579; Dissertation of G. Elender, Technical University of Munich, 1996, p. 113). These three references are incorporated herein by reference.
The state of the art is the stabilization of the linker molecule layer by the use of linkers with long alkyl chains that provide a dense and stable layer due to crystallization of the alkyl chains (EP-B-589 867).
One important advantage of a layered structure that makes use of hydrogen bonds or aromatic-aromatic interactions is the fact that it is very easy to prepare. On the other hand, layered structures using a metal oxide interlayer are more complex to prepare but offer the possibility of precisely controlling the layer thickness of the overall system, optionally by performing several consecutive sol-gel process steps. The layer thickness allows in turn to influence the minimum position relating to the surface plasmon resonance signal, which may be desirable from a measurement point of view.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the surface plasmon resonance curves before and after the bonding of carboxymethyldextran to an amino-functionalized gold surface.
FIG. 2 shows the surface plasmon resonance curves before and after the bonding of bovine serum albumin to a carboxymethydextran-functionalized gold surface.
FIG. 3 shows the evolution of the minimum angle in surface plasmon resonance measurements with sheep-anti-mouse IgG solution and with bovine serum albumin solution.
DETAILED DESCRIPTION OF THE INVENTION
The biosensor of the present invention comprises a layer of precious metal, which may be e.g. silver or gold in terms of the invention. The film has a thickness between 30 and 70 nm, preferably between 40 and 60 nm.
The linker molecules used are short-chained organic A—R—B molecules with an atom or group A providing the bonding to the precious metal. Preferred substances are thiols, disulfides, selenides and diselenides with an additional functional group. The linker molecule has a branched or straight hydrocarbon chain with a chain length of up to 10 carbon atoms, which can be interrupted in up to two places each by a phenylene group or a heteroatom such as —O— or —NH—. The heteroatoms and/or the carbons of the phenylene groups are not considered for the calculation of the chain length. The hydrocarbon chain has preferably a length of up to 6 carbon atoms. The hydrocarbon chain is preferably of the straight type.
Thiols and disulfides being less expensive than the equivalent selenium compounds, they are preferably used in the inventive biosensors having a modified precious metal surface.
The linker molecule's second functional group B provides the bonding with the hydrogel, the surfactant or the biotin, or the bonding with the dense metal oxide layer. In principle, all known state-of-the-art B groups may be used, e.g. hydroxyl, carboxyl, epoxide or amino groups. In the case of the interlayer comprising metal oxide, preference is given to hydroxyl groups, whereas in the case of direct bonding of the hydrogel, the surfactant or the biotin to the low molecular weight linker the use of epoxide or amino groups is particularly preferred.
All known surfactants are suitable as surfactants (cf.: Die Tenside, published by: K. Kosswig, H. Stracke, C. Hauser Verlag, Munich, 1993 which is incorporated herein by reference). For example, surfactants with an anionic group, such as carboxylates, sulfonates, sulfates, ether sulfates, phosphates, phosphites, phosphonates, phosphinates and thiosulfates are suitable. Carboxylates, phosphonates and sulfonates are particularly preferred. Alkali metal ions and ammonium ions NH 4 + are suitable counterions for anionic surfactants. Surfactants with a cationic group, such as ammonium salts, pyridinium salts and sulfonium salts, are also suitable. Particularly preferred cationic surfactants are quaternary ammonium salts. Counterions of cationic surfactants are mainly halides, especially chloride. Surfactants with zwitterionic groups are also suitable for the surfactant layer of the present invention. Examples are amino carbonic acids, betains, sulfobetains and lecithins (e.g. phospholipids). Among the zwitterionic surfactants, lecithins are particularly preferred. All surfactants have in addition to the aforementioned hydrophilic group a hydrophobic group which may be e.g. C n H 2n+1 —, C n H 2n−1 —, C n H 2n+1 —C 6 H 4 —, C n F 2n+1 or H 3 C(—Si(CH 3 ) 2 —O) m —. Except in the case of silicone surfactants, the hydrophobic groups usually have between 6 and 22 carbon atoms. With silicone surfactants, n is usually between 4 and 20.
Biotin-functionalized biosensor surfaces are suited for the selective determination of streptavidin.
The hydrogel used may be a polysaccharide, a polysaccharide derivative or a swellable organic polymer such as poly{N-[tris-(hydroxymethyl)-methyl]acrylic acid amide}, polyvinyl alcohol or polyethylene glycol. Poly{N-[tris-(hydroxymethyl)-methyl]acrylic acid amide} and polyethylene glycol are preferred.
Examples of polysaccharides are amylose, inulin, pullulan or dextran. Preferred polysaccharides are pullulan and dextran, in particular dextran.
In order to facilitate the bonding of the hydrogel to the linker modules, the hydrogel may be derivatized to comprise e.g. hydroxyl, carboxyl, amino or carbonyl groups. Carboxymethyl-derivatized hydrogel is particularly preferred.
Two preferred embodiments are given to explain the present invention in more detail. In the first embodiment, the hydrogel, the surfactant layer or the biotin is bonded directly to the linker molecules, i.e. without the introduction of further atoms between the hydrogel, the surfactant layer or the biotin and the linker molecules. Reaction scheme 1 shows an example of this. In a first step, a monolayer of aminothiol is applied to the precious metal surface. In a second step, a carboxyalkyl-derivatized polysaccharide is bonded directly to this linker molecule monolayer by means of amide bonds.
The amide bonding is typically performed using ethyl-3-dimethylamino-propyl-carbodiimide and N-hydroxysuccinimide. After this step, the functionalization is completed to such an extent that the end user can perform the bonding of receptor molecules.
In this embodiment, only two steps are required to prepare a carboxyalkylated polysaccharide surface. Moreover, there is no need to use highly toxic and carcinogenic substances. A highly concentrated polymeric solution is not required. A further advantage is the fact that only aqueous solutions are used in this embodiment.
In a second preferred embodiment, the hydrogel, the surfactant layer or the biotin are bonded to the linker molecules by means of a metal oxide interlayer. Reaction scheme 2 shows an example of this. In a first step, a hydroxythiol monolayer is bonded to a precious metal layer. These linker molecules are then reacted with a metal alkoxide, preferably Ti(IV)butoxide. A hydrolysis is then performed to obtain a hydroxy-functionalized surface. The chemical reactivity of the metal oxide layer obtained in this way is equivalent to that of purified glass. It is now possible to bond e.g. an expoxy silan to the hydroxy groups, which in turn allows the bonding of a hydroxy polymer. The hydroxy polymers used may be polysaccharides or synthetic polymers containing hydroxy groups, such as dextran or its derivatives, polyvinyl alcohol, pullulan and poly{N-[(tris-(hydroxymethyl)-methyl]acrylic acid amide}. To facilitate the bonding of surfactants or biotin, the metal oxide-comprising interlayer should preferably be derivatized with N-hydroxysuccinimide. The metal oxide-comprising interlayer should preferably essentially completely consist of metal oxide.
To prepare a biosensor surface according to the present invention, a glass support with a vapor deposited gold layer is placed in a, preferably aqueous, solution of linker molecules of the present invention. The duration of this functionalization is between 2 h and 24 h, typically 12 h. The temperature can be between 15° C. and 35° C. The concentration of linker molecules in the solution ranges from 5·10 −4 to 2·10 −1 mole·l −1 , preferably from 5·10 −3 to 5·10 −2 mole·l −1 .
The intermediate product thus produced has a monolayer of organic linker molecules of the invention. The hydrogel, the surfactant layer or the biotin may be bonded to it directly or by means of a metal oxide-comprising interlayer.
For direct bonding of the hydrogel, the surfactant or the biotin to the linker molecule monolayer, the support is placed for 1 h to 5 h, typically 3 h, into a respective freshly prepared aqueous solution. The concentration is between 10 and 50 mg·ml −1 . The hydrogel may optionally be derivatized according to known methods.
To produce a metal oxide interlayer, on the other hand, the first step is to prepare a metal alkoxide solution of metal alkoxide, water and organic solvents such as ethanol or toluol. The metal oxide layer can be prepared e.g. using titanium(IV)butoxide, tetramethoxy silan, aluminum(III)butoxide, zirconium(IV)propoxide or niobium(V)butoxide. The preferred substance is titanium(IV)butoxide. The intermediate product is then immersed into this metal alkoxide solution for 5 to 20 minutes.
To allow the bonding of the hydrogel, the metal oxide layer thus obtained should be functionalized. This can be done by known methods using epoxy silan compounds such as (3-(2,3-epoxypropoxy)propyl)triethoxy silan. This functionalization step can be performed at room temperature and lasts between 10 and 40 minutes.
The bonding of a hydroxy polymer is performed in a similar way as with the first embodiment, except that the duration of immersion in the hydroxy polymer solution is extended to between 12 and 48 h, typically 24 h.
A more detailed explanation of the present invention is given in the following examples.
EXAMPLES
Example 1
Preparation of the Functionalized Surface
A gold-coated glass support (film thickness: approx. 50 nm) is immersed for 12 h into a 2·10 −2 mole·l −1 aqueous solution of cysteaminium hydrochloride. After rinsing with 100 ml of ultrapure water and 10 ml of 0.1 mole·l −1 NaOH, the support is placed for 3 h into a solution of 22 mg of sodium salt of carboxymethyldextran (Fluka), 77 mg of ethyl-3-dimethylamino-propyl-carbodiimide (EDC) and 12 mg of N-hydroxysuccinimide (NHS) in 1 ml of ultrapure water. After this, the support is rinsed three times with 20 ml of ultrapure water.
The carboxymethyl-functionalized sensor is mounted in an SPR instrument. The SPR instrument used is designed by the inventor and is of the θ/2θ type (in analogy to E. Kretschmann and H. Raether, “Radiative Decay of Non-Radiative Surface Plasmons Excited by Light”, Z. Naturforsch., Vol. 23a, p. 2135 (1968) which is incorporated herein by reference), that is equipped with an infrared laser (wave length 784 nm) as its light source.
FIG. 1 shows the measurement of the surface plasmon resonance after the amino-functionalization (solid line) and after bonding of the carboxymethyldextran (dashed line).
The displacement of the minimum towards a higher incidence angle serves as an indicator for the growth of the layer in thickness.
Bonding of a Protein
To activate the carboxyl groups of the dextran layer, the surface is brought into contact with 77 mg of EDC and 12 mg of NHS for 10 minutes. After this, a bovine serum albumin solution (BSA) (16.7 μmole·l −1 ) is brought into contact with the surface. After 20 minutes the surface is rinsed with 1 ml of water and then with 1 ml of 0.01 mole·l −1 hydrochloric acid to remove unspecifically bonded BSA. in a next step, a surface plasmon resonance measurement is performed to monitor the growth of the layer in thickness (cf. FIG. 2 ).
Example 2
A gold-coated glass support (film thickness: approx. 50 nm) is immersed for 12 h into a 2·10 −2 mole·l −1 aqueous solution of mercaptoethanol. After thorough rinsing with ultrapure water, the support is placed into a freshly prepared titanium(IV)butoxide solution. This solution is prepared by adding 7 ml of water and 34 mg of titanium(IV)butoxide (Aldrich) to a mixture of 0.5 ml of ethanol and 0.5 ml of toluol, stirring continuously. After an immersion time of 10 minutes the support is washed with plenty of ultrapure water. After this, another functionalization step is performed using (3-(2,3-epoxypropoxy)propyl)triethoxy silan (Wacker GF 82).
For this functionalization, 7 ml of silan and 3 ml of H 2 O are mixed, diluted with 190 ml of isopropanol and stirred at room temperature. The immersion time of the support in this solution is again 20 minutes. Next, the support is washed with plenty of ultrapure water and placed for 24 h in a 30 weight % solution of dextran (Dextran T500, Pharmacia) in water. After washing, the support is placed in a freshly prepared solution of bromoacetic acid in aqueous NaOH. This solution has a bromoacetic acid concentration of 1 mole·l −1 and a NaOH concentration of 2 mole·l −1 . The immersion time is 20 h.
The carboxymethyl-functionalized sensor is mounted in the SPR instrument described in example 1. The sensor surface is activated for 10 minutes by incubation in an aqueous solution of 77 mg·ml −1 of ethly-3-dimethylamino-propyl-carbodiimide and 12 mg/ml of N-hydroxysuccinimide.
For bonding of the receptor, a solution of protein A (10 μg·ml −1 ) in a PBS buffer (0.15 mole·l −1 NaCl, 0.38 mmole·l −1 NaH 2 PO 4 ·H 2 O, 1.67 mmole·l −1 Na 2 HPO 4 , pH 7.4) is applied to the surface pretreated in this way. The incubation time is 60 minutes. To deactivate carboxyl groups that are not reacted, incubation for 20 minutes with a 1 mole·l −1 solution of ethanolamin in water is performed.
After rinsing with the PBS buffer solution, the ligand/receptor interaction can be observed. For this, a solution of sheep-anti-mouse IgG (270 μg·ml −1 ) in PBS buffer is brought into contact with the sensor surface. The time dependence of the sheep-anti-mouse IgG ligand bonding (circles) can be monitored by monitoring the position of the plasmon minimum in dependence of the time (FIG. 3 ). The shift of the minimum towards a higher incidence angle serves as an indicator for the growth of the layer in thickness.
After the bonding is completed, the sensor surface can be regenerated by rinsing it twice with diluted hydrochloric acid (triangles). A check measurement using a bovine serum albumin solution with a comparable concentration (270 μg·ml −1 ) shows that the interaction with the sheep-anti-mouse IgG is a specific one: there is no bonding of the bovine serum albumin which has a very strong tendency to unspecific adsorption (lozenges). | The present invention relates to a biosensor (affinity sensor) in which a hydrogel, a surfactant layer or biotin are bonded to the biosensor's precious metal surface by means of a short-chained linker, as well as to the process for the preparation thereof. A complete covering of the biosensor surface with the hydrogel, the surfactant layer or the biotin is achieved by hydrogen bonds, aromatic-aromatic interactions or by covalent bonds. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the National Stage of International Application No. PCT/CN2010/079550, filed Dec. 8, 2010, which claims the benefit of Chinese Application No. 200910250793.1, filed Dec. 11, 2009, the disclosures of which are incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
The present application relates to a flow control method in an oil-gas well exploitation field, and in particular to a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe.
BACKGROUND OF THE INVENTION
An oil-gas well generally refers to a production well in the oil-gas field development in a broad sense, including an oil well, a gas well, an injection well and so on. In the production process of the oil-gas well, due to the heterogeneous characteristic of the oil reservoir, the oil-gas well, regardless of a vertical well or a horizontal well, has to be sealed off and separated into multiple independent zones for production. The oil-gas well production mentioned herein includes the production and injection of the fluid in the oil-gas well production process, for example, injecting water and vapor into the formation in the petroleum exploitation or production process, and injecting chemical agents for improving the oil field recovery ratio, and also includes the injection of acid liquor into the formation in some operation processes, etc.
During the process of sealing off and separating the oil-gas well into multiple independent zones for production, a device for controlling flow rate in sections (for example, a flow control filter string), and a device for separating the production section of the oil-gas well into several flow units along the axial direction of the oil-gas well (for example, a packer) are generally used to realize the seal and separation of the zones, so as to realize relatively independent production.
FIG. 1 is a schematic view illustrating the flow control by using a flow control filter string and a packer in an open hole. In FIG. 1 , reference numeral 1 indicates a borehole wall of the oil-gas well, reference numeral 2 indicates a flow control filter string, reference numeral 3 indicates an annular space between the flow control filter string and the borehole wall, reference numeral 4 indicates a packer hung with the flow control filter string, and reference numeral 5 indicates a flow control packer.
The process of sectional flow control is briefly described hereinafter with reference to FIG. 1 . FIG. 1 shows a non-oil-bearing formation, an oil-bearing formation and bottom water under the oil-bearing formation. Various formations are schematically indicated by horizontal lines in FIG. 1 , though the person skilled in the art may understand that these formations may not be horizontal, which depends on the geologic structure of the locality where the oil-gas well is located. The oil-gas well as shown in the figure includes a vertical section and a horizontal section. The horizontal section substantially extends along the oil-bearing formation so as to increase the contact area between the borehole wall and the oil-bearing formation. FIG. 1 illustratively shows two zones having different permeability, i.e. a high permeability zone and a low permeability zone. Under the situation without flow control in the oil-gas well (i.e. no packer 5 is provided in FIG. 1 ), since the permeability of the two zones is different, a flow rate of the fluid in the high permeability zone is larger than a flow rate of the fluid in the low permeability zone. In this case, due to the difference between the pressure of the bottom water and the pressure inside the oil-gas well, the bottom water under the oil-bearing formation may firstly pass through the high permeability zone and enter into the oil-gas well, which may cause the decrease of oil and gas and the increase of water in the production of the oil-gas well. This should be avoided in the production.
Currently, as shown in FIG. 1 , the sectional flow-rate control production in many oil-gas wells is realized as follows. A flow control filter string 2 is lowered into the production section inside the oil-gas well, and the flow control filter string 2 and the packer 5 are used to effectively seal off and partition an annular space between the flow control filter string 2 and the production section inside the oil-gas well, i.e. axial channeling passage of fluid outside the flow control filter string is blocked, thereby realizing a better sectional flow-rate control production. Generally, the packer is provided between two zones having different permeability. Since the flow control filter can play a role of flow-rate control, the packer is used to pack off the zones having different permeability so as to perform independent control or sectional control of various zones having different permeability. Therefore, it is possible for the oil-gas well to achieve a good production, and to effectively control the quantity of the bottom water entering into the oil-gas well.
However, the current well completion of the oil-gas well is achieved by running a perforated pipe into an open hole, and an annular space between the perforated pipe and the open hole wall is not sealed by filling cement or other materials between the perforated pipe and the borehole wall. The well completion method has an advantage of the low cost, and a disadvantage that the annular space becomes a passage for fluid channeling, so that it is difficult to realize the sectional flow control in the later production. Each meter of the perforated pipe is provided with several to dozens of holes with a diameter about 10 mm. The perforated pipe is mainly used in the oil-gas well to support the borehole wall and prevent lumps in the well from entering into the perforated pipe so as to ensure that the whole flow passage of the oil-gas well is not blocked by lumps.
As shown in FIG. 2 , if the flow control technology using the packer in the open hole as shown in FIG. 1 is directly applied in the existing oil-gas well having the perforated pipe, the annular space between the perforated pipe and the borehole wall cannot be packed off. Thus, the bottom water entering into the oil-gas well may flow axially in the annular space between the perforated pipe and the borehole wall. Thus, the annular space between the perforated pipe and the borehole wall forms an axial channeling passage, which destroys the pack-off effect between the flow control filter string in the perforated pipe and the perforated pipe, and cannot control the amount of water satisfactorily. In FIG. 2 , reference numeral 11 indicates a borehole wall of the oil-gas well, reference numeral 12 indicates a perforated pipe, reference numeral 13 indicates an annular space between the perforated pipe and the borehole wall, reference numeral 14 indicates a packer hung with the perforated pipe, reference numeral 15 indicates a flow control filter string, reference numeral 16 indicates a flow control filter on the flow control filter string, reference numeral 17 indicates a packer provided in the annular space between the flow control filter string and the perforated pipe, and reference numeral 18 indicates a packer hung with the flow control filter string. A direction of arrows in the figure indicates the fluid channeling direction. As shown in FIG. 2 , the fluid in the formation passes through the borehole wall and enters into the annular space between the borehole wall and the perforated pipe, so that the axial channeling is formed in the annular space between the borehole wall and the perforated pipe, and then passes through the flow control filter and enters into the flow control filter string. This axial channeling destroys the pack-off effect of the packer provided between the flow control filter string and the perforated pipe, thus a good water control effect can not be realized.
SUMMARY OF THE INVENTION
A technical problem to be solved by the present application is to provide a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe, in which the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with anti-channeling pack-off particles, so as to realize a good pack-off effect, thereby realizing a good sectional flow control production.
For solving the above problem, one embodiment of the present application provides a sectional flow control method in an oil-gas well, wherein the oil-gas well includes a first annular space formed between a borehole wall of the oil-gas well and a perforated pipe, and a second annular space formed between the perforated pipe and a flow control filter string. The perforated pipe is located inside the oil-gas well and extends along an axial direction of the oil-gas well. The flow control filter string is located inside the perforated pipe and extends along the axial direction of the oil-gas well. The method includes the step of: filling anti-channeling pack-off particles into the first annular space and the second annular space such that fluid can flow in a penetration manner in the first annular space and the second annular space filled with the anti-channeling pack-off particles.
Preferably, filling the anti-channeling pack-off particles into the first annular space and the second annular space is performed by injecting particle-carrying fluid with the anti-channeling pack-off particles into the first annular space and the second annular space.
Preferably, the particle-carrying fluid has a density substantially equal to a density of the anti-channeling pack-off particles.
Preferably, the particle-carrying fluid is water or aqueous solution.
Preferably, the anti-channeling pack-off particles are high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.4 g/cm 3 .
Preferably, the anti-channeling pack-off particles are high molecular polymer particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.94 g/cm 3 to 1.06 g/cm 3 .
Preferably, the anti-channeling pack-off particles are high-density polyethylene particles with an average particle size ranging from 0.1 mm to 0.05 mm and a density ranging from 0.90 g/cm 3 to 0.98 g/cm 3 .
Preferably, the anti-channeling pack-off particles are styrene and divinylbenzene crosslinking copolymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.96 g/cm 3 to 1.06 g/cm 3 .
Preferably, the anti-channeling pack-off particles are polypropylene and polyvinyl chloride high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.2 g/cm 3 .
Preferably, the anti-channeling pack-off particles are filled into the first annular space and the second annular space until the first annular space and the second annular space are substantially full of the anti-channeling pack-off particles, and the first annular space and the second annular space are closed. Preferably, the oil-gas well is a horizontal well or an inclined well.
Preferably, a difference between a density of the particle-carrying fluid and a density of the anti-channeling pack-off particles is within a range of ±0.4 g/cm 3 or a range of ±0.2 g/cm 3 .
According to another embodiment of the present application, a sectional flow control system for an oil-gas well is provided, including: a first annular space formed between a borehole wall of the oil-gas well and a perforated pipe; a second annular space formed between the perforated pipe and a flow control filter string; and anti-channeling pack-off particles. The perforated pipe is located inside the oil-gas well and extends along an axial direction of the oil-gas well. The flow control filter string is located inside the perforated pipe and extends along the axial direction of the oil-gas well. The anti-channeling pack-off particles are filled in the first annular space and the second annular space such that fluid can flow in a penetration manner in the first annular space and the second annular space filled with the anti-channeling pack-off particles.
Preferably, the first annular space and the second annular space are filled by injecting particle-carrying fluid with the anti-channeling pack-off particles into the first annular space and the second annular space.
Preferably, the particle-carrying fluid has a density substantially equal to a density of the anti-channeling pack-off particles.
Preferably, the particle-carrying fluid is water or aqueous solution.
Preferably, the anti-channeling pack-off particles are high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.4 g/cm 3 .
Preferably, the anti-channeling pack-off particles are high molecular polymer particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.94 g/cm 3 to 1.06 g/cm 3 .
Preferably, the anti-channeling pack-off particles are high-density polyethylene particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.90 g/cm 3 to 0.98 g/cm 3 .
Preferably, the anti-channeling pack-off particles are styrene and divinylbenzene crosslinking copolymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.96 g/cm 3 to 1.06 g/cm 3 .
Preferably, the anti-channeling pack-off particles are polypropylene and polyvinyl chloride high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.2 g/cm 3 .
Preferably, the first annular space and the second annular space are substantially full of the anti-channeling pack-off particles, and are closed.
Preferably, the oil-gas well is a horizontal well or an inclined well.
Preferably, a difference between the density of the particle-carrying fluid and the density of the anti-channeling pack-off particles is within a range of ±0.4 g/cm 3 or a range of ±0.2 g/cm 3 .
According to another embodiment of the present application, a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe is provided, wherein the oil-gas well having the perforated pipe includes a borehole wall of the oil-gas well and the perforated pipe running in the oil-gas well, one end of the perforated pipe adjacent to a wellhead is fixedly connected to the borehole wall, and an annular space is formed between the perforated pipe and the borehole wall.
The sectional flow control method using a flow control filter string includes the following steps:
1) running the flow control filter string into the perforated pipe via a running string, wherein the flow control filter string is provided with a flow control filter, one end of the flow control filter string adjacent to the wellhead is fixedly connected to the borehole wall, and an annular space is formed between the flow control filter string and the perforated pipe;
2) injecting particle-carrying fluid with the anti-channeling pack-off particles into the annular space between the flow control filter string and the perforated pipe, wherein the particle-carrying fluid carrying the anti-channeling pack-off particles passes through holes in the perforated pipe and into the annular space between the perforated pipe and the borehole wall, the anti-channeling pack-off particles are accumulated both in the annular space between the flow control filter string and the perforated pipe and in the annular space between the perforated pipe and the borehole wall, so that the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with and full of the anti-channeling pack-off particles, a part of the particle-carrying fluid enters into the flow control filter and then flows back to the ground, and another part of the particle-carrying fluid passes through the borehole wall and penetrates into the formation;
3) closing the annular space full of the anti-channeling pack-off particles between the flow control filter string and the perforated pipe; and
4) disengaging the running string which is connected to the flow control filter string, and forming a well completion structure in which the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with the anti-channeling pack-off particles.
The particle density mentioned in the present application is the true density of the individual particles, rather than the packing density of the particles.
The present application uses water or aqueous solution with a density about 1 g/cm 3 as the particle-carrying fluid to carry anti-channeling pack-off particles, and the present application uses anti-channeling pack-off particles having almost the same density as the particle-carrying fluid, thus the particle-carrying fluid may easily carry the anti-channeling pack-off particles to fill in the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall. The anti-channeling pack-off particles are accumulated both in the annular space between the flow control filter string and the perforated pipe and in the annular space between the perforated pipe and the borehole wall, so that the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with and full of the anti-channeling pack-off particles. A part of the particle-carrying fluid enters into the flow control filter and then flows back to the ground, and another part of the particle-carrying fluid passes through the borehole wall and penetrates into the formation. Finally, a well completion structure is formed, in which the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with the anti-channeling pack-off particles. The anti-channeling pack-off particles are filled tightly and there is almost no channeling. The oil-gas well may effectively be sealed off and separated into multiple independent zones with combination of the flow control filter string, so as to perform oil-gas well production, realize the object of flow control, and facilitate the flow-rate sectional management, thereby bringing good effects of the oil-gas well production, for example, improving the production efficiency of the oil-gas well.
Furthermore, even there still has channeling after filling with the anti-channeling pack-off particles, in production axial channeling of small flow rate of fluid may bring the anti-channeling pack-off particles to move and to be accumulated towards the channeling direction and then to fully fill the channeling passage, thereby achieving a very good anti-channeling pack-off effect and realizing the object of sectional flow control using a flow control filter string in an oil-gas well with the combination of a flow control filter string.
The formation fluid flows in media formed by the accumulation of the anti-channeling pack-off particles in the penetration manner. According to the principle of the penetration fluid mechanics, the penetration resistance is proportional to the penetration distance, and is inversely proportional to the penetration area. The accumulation body of the anti-channeling pack-off particles has a thin thickness, a small section and a long axial length. Accordingly, a channeling resistance of the formation fluid flowing in the anti-channeling pack-off particles along the axial direction of the oil-gas well is very high. However, when the formation fluid flows along the radial direction of the oil-gas well, the penetration area is big and the penetration distance is short, thus the flow resistance is very small. The resistance flowing in the accumulation body for several meters or tens of meters along the axial direction of the oil-gas well is hundreds times even thousands times more than the resistance flowing in the accumulation body for several centimeters along the radial direction of the oil-gas well. Due to the great difference between the resistance flowing in the accumulation body along the axial direction of the oil-gas well and the resistance flowing in the accumulation body along the radial direction of the oil-gas well, the flow rate flowing in the accumulation body along the axial direction of the oil-gas well is far less than the flow rate flowing in the accumulation body along the radial direction of the oil-gas well under the same pressure difference. Thus, under the difference between the resistance flowing in the accumulation body of the anti-channeling pack-off particles along the axial direction of the well and the resistance flowing in the accumulation body along the radial direction of the well, the smooth flow of the formation fluid in the accumulation body along the radial direction of the oil-gas well may be ensured, and the flow of the formation fluid along the axial direction of the oil-gas well may be limited, thereby functioning as a packer.
The present application provides a convenient and useful sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe, which may pack off the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall, thereby having a good pack-off effect, realizing the sectional flow control production well, and satisfying the actual production requirements of the oil field, for example, improving the oil recovery ratio.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating the flow control by using a flow control filter string and a packer in an open hole in the prior art;
FIG. 2 is a schematic view of a hypothetical state where the flow control technology using the flow control filter string and the packer as shown in FIG. 1 is applied to an oil-gas well having a perforated pipe, the flow control filter string is lowered into the perforated pipe, an annular space between the flow control filter string and the perforated pipe is packed off, while an annular space between the perforated pipe and a borehole wall is not packed off;
FIG. 3 is a schematic view of a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe according to an embodiment of the present application; and
FIG. 4 is a schematic view of a well completion structure according to an embodiment of the present application, in which an annular space between the flow control filter string and the perforated pipe and an annular space between the perforated pipe and a borehole wall are both filled with anti-channeling pack-off particles.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Overall, the present application provides a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe. The oil-gas well having the perforated pipe therein includes a borehole wall of the oil-gas well and the perforated pipe running into the oil-gas well. One end of the perforated pipe adjacent to a wellhead is fixedly connected to the borehole wall, and an annular space is formed between the perforated pipe and the borehole wall.
The sectional flow control method using the flow control filter string includes the following steps:
1) running the flow control filter string into the perforated pipe via a running string, wherein the flow control filter string is provided with a flow control filter, one end of the flow control filter string adjacent to a wellhead is fixedly connected to the borehole wall, and an annular space is formed between the flow control filter string and the perforated pipe;
2) injecting a particle-carrying fluid into the annular space between the flow control filter string and the perforated pipe; wherein the particle-carrying fluid carries the anti-channeling pack-off particles, the particle-carrying fluid carrying the anti-channeling pack-off particles passes through holes in the perforated pipe and enters into an annular space between the perforated pipe and the borehole wall, the anti-channeling pack-off particles are accumulated both in the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall, so that the annular space between the flow control filter string and the perforated pipe as well as the annular space between the perforated pipe and the borehole wall is filled with and full of the anti-channeling pack-off particles, a part of the particle-carrying fluid enters into the flow control filter and then flows back to the ground, and another part of the particle-carrying fluid passes through the borehole wall and penetrates into the formation;
3) closing the annular space full of the anti-channeling pack-off particles between the flow control filter string and the perforated pipe; and
4) disengaging the running string which is connected to the flow control filter string, and forming a well completion structure in which the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with the anti-channeling pack-off particles.
The particle-carrying fluid carrying the anti-channeling pack-off particles is water or aqueous solution.
The anti-channeling pack-off particles may be high molecular polymer particles with a particle size ranging from 0.05 mm to 0.7 mm and a density ranging from 0.8 g/cm 3 to 1.2 g/cm 3 .
The anti-channeling pack-off particles may be high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.4 g/cm 3 .
The anti-channeling pack-off particles may be high molecular polymer particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.94 g/cm 3 to 1.06 g/cm 3 .
The anti-channeling pack-off particles may be high-density polyethylene particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.90 g/cm 3 to 0.98 g/cm 3 .
The anti-channeling pack-off particles may be styrene and divinylbenzene crosslinking copolymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.96 g/cm 3 to 1.06 g/cm 3 .
The anti-channeling pack-off particles may be polypropylene and polyvinyl chloride high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.2 g/cm 3 .
The embodiments of the present application will be described in detail with reference to the drawings hereinafter.
First Embodiment
The embodiment of the present application provides a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe. As shown in FIG. 3 , the oil-gas well structure having the perforated pipe includes a borehole wall 101 of the oil-gas well and a perforated pipe 102 running in the oil-gas well. Each meter of the perforated pipe 102 is provided with multiple small holes. For example, the number of the small holes is 30 . The diameter of the small holes is configured to be able to prevent lumps from entering into the perforated pipe 102 , for example 10 mm. A packer 104 hung with the perforated pipe 102 is provided between an upper portion of the perforated pipe 102 and the borehole wall 101 . An annular space 103 is formed between the perforated pipe 102 and the borehole wall 101 .
The water control pack-off method according to the embodiment of the present application is described in detail with reference to FIG. 3 hereinafter, which includes the following steps.
A flow control filter string 105 is run into the perforated pipe 102 via a running string (not shown). A flow control filter 106 is provided on the flow control filter string 105 . A packer 108 hung with the flow control filter string 105 is provided between an upper portion of the flow control filter string 105 and the borehole wall 101 . An annular space 103 is formed between the flow control filter string 105 and the perforated pipe 102 .
A particle-carrying fluid 110 carrying the anti-channeling pack-off particles is injected into the annular space 103 between the flow control filter string 105 and the perforated pipe 102 . The particle-carrying fluid 110 carrying the anti-channeling pack-off particles passes through small holes in the perforated pipe 102 and enters into the annular space 111 between the perforated pipe 102 and the borehole wall 101 . The anti-channeling pack-off particles are accumulated both in the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and in the annular space 111 between the perforated pipe 102 and the borehole wall 101 , so that the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and the annular space 111 between the perforated pipe 102 and the borehole wall 101 are filled with and full of the anti-channeling pack-off particles. A part of the particle-carrying fluid penetrates through the flow control filter 106 and enters into the flow control filter string 105 and then flows back to the ground, and another part of the particle-carrying fluid passes through the borehole wall 101 and penetrates into the formation. The direction of arrows in FIG. 3 is the flowing direction of the particle-carrying fluid. The anti-channeling pack-off particles are high-density polyethylene particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.90 g/cm 3 to 0.98 g/cm 3 . The particle-carrying fluid is water.
The packer 108 hung with the flow control filter string 105 is set so as to close both the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and the annular space 111 between the perforated pipe 102 and the borehole wall 101 which are filled with the anti-channeling pack-off particles.
The running string (not shown) connected to the flow control filter string 105 is disengaged and a well completion structure is formed. In the well completion structure, the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and the annular space 111 between the perforated pipe 102 and the borehole wall 101 are filled with the anti-channeling pack-off particles, as shown in FIG. 4 . In FIG. 4 , reference numeral 101 indicates the borehole wall of the oil-gas well, reference numeral 102 indicates the perforated pipe, reference numeral 104 indicates the packer hung with the perforated pipe, reference numeral 105 indicates the flow control filter string, reference numeral 106 indicates the flow control filter on the flow control filter string, reference numeral 107 indicates the anti-channeling pack-off particles filled the annular space between the flow control filter string and the perforated pipe, reference numeral 108 indicates the packer hung with the flow control filter string, and reference numeral 109 indicates the anti-channeling pack-off particles filled the annular space between the perforated pipe and the borehole wall.
Second Embodiment
In the embodiment of the present application, the anti-channeling pack-off particles are polypropylene and polyvinyl chloride high molecular polymer particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density being 0.97 g/cm 3 .
The other steps of the method are the same as the first embodiment.
Third Embodiment
In the embodiment of the present application, the anti-channeling pack-off particles are styrene and divinylbenzene crosslinking copolymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.96 g/cm 3 to 1.06 g/cm 3 .
The other steps of the method are the same as the first embodiment.
In the first, second and third embodiments of the present application, water is used to carry the anti-channeling pack-off particles. The density of water is 1 g/cm 3 . The density of the anti-channeling pack-off particles selected in the present application is almost the same as the density of water. Therefore, the water may easily carry the anti-channeling pack-off particles to fill in the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and the annular space 111 between the perforated pipe 102 and the borehole wall 101 . The anti-channeling pack-off particles are accumulated both in the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and in the annular space 111 between the perforated pipe 102 and the borehole wall 101 , so that the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and the annular space 111 between the perforated pipe 102 and the borehole wall 101 are filled with and full of the anti-channeling pack-off particles. A part of the water passes through the flow control filter 106 and enters into the flow control filter string 105 and then flows back to the ground, and another part of the water passes through the borehole wall 101 and penetrates into the formation. Finally, a well completion structure is formed, in which the annular space 103 between the flow control filter string 105 and the perforated pipe 102 and the annular space 111 between the perforated pipe 102 and the borehole wall 101 are filled with the anti-channeling pack-off particles.
The formation fluid flows in media formed by the accumulation of the anti-channeling pack-off particles in a penetration manner. According to the principle of the penetration fluid mechanics, the penetration resistance is proportional to the penetration distance, and is inversely proportional to the penetration area. The accumulation body of the anti-channeling pack-off particles is a medium having a thin thickness, a small section and a long axial length, thus the channeling resistance of the formation fluid flowing in the accumulation body of the anti-channeling pack-off particles along the axial direction of the oil-gas well is very high. However, when the formation fluid flows along the radial direction of the oil-gas well, the penetration area is big and the penetration distance is short, thus the flow resistance is very small. The resistance flowing in the accumulation body for several meters or tens of meters along the axial direction of the oil-gas well is hundreds times even thousands times more than the resistance flowing in the accumulation body for several centimeters along the radial direction of the oil-gas well. Due to the great difference between the resistance flowing in the accumulation body along the axial direction of the oil-gas well and the resistance flowing in the accumulation body along the radial direction of the oil-gas well, the flow rate flowing in the accumulation body along the axial direction of the oil-gas well is far less than the flow rate flowing in the accumulation body along the radial direction of the oil-gas well under the same pressure difference. Under the difference between the resistance flowing in the accumulation body of the anti-channeling pack-off particles along the axial direction of the well and the resistance flowing in the accumulation body along the radial direction of the well, the smooth flow of the formation fluid in the accumulation body along the radial direction of the oil-gas well may be ensured, and the flow of the formation fluid along the axial direction of the oil-gas well may be limited, thereby functioning as a packer.
The present application provides a convenient and useful sectional flow control method in an oil-gas well having a perforated pipe, which may pack off both the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall. The sectional flow control production may be realized due to the good pack-off effect, so as to improve the oil recovery ratio and satisfy the actual production requirements of the oil field.
The production section referred in the present application is a generalized production section. There may be some non-flowing sections (for example, an interlayer, a sandwich layer and an imperforated interval after the casing cementing) along the length of the production section.
The flow control filter string in the present application includes filtering sections and blank sections which are arranged alternately. The blank section is a pipe without holes on its wall surface. The anti-channeling pack-off particle ring outside the blank sections plays a major role in preventing the axial channeling. The blank sections are provided in two ways. On the one hand, each filter itself includes a filtering section and blank sections provided at two ends of the filter and provided with screw threads, so that two filters may be connected via the screw threads on the blank sections of the two filters. When screwing and connecting the filters above the well, the blank section is a place for setting the pliers. On the other hand, an additional blank section may be connected between two filters. Under the situation that a relatively long flow control filter string is desired, the flow control filter string may be formed by connecting multiple flow control filters in series.
The anti-channeling pack-off particles in the present application is preferably circular.
In the embodiments of the present application, a sectional flow control method using a flow control filter string in an oil-gas well having a perforated pipe is provided, wherein the oil-gas well having the perforated pipe includes a borehole wall of the oil-gas well and the perforated pipe running into the oil-gas well, one end of the perforated pipe adjacent to a wellhead is fixedly connected to the borehole wall, and an annular space is formed between the perforated pipe and the borehole wall.
The sectional flow control method using a flow control filter string is characterized by including the following steps:
1) running the flow control filter string into the perforated pipe via a running string, the flow control filter string being provided with a flow control filter, the flow control filter string being fixed connected to the borehole wall, and an annular space being formed between the flow control filter string and the perforated pipe;
2) injecting particle-carrying fluid, which carries the anti-channeling pack-off particles, into the annular space between the flow control filter string and the perforated pipe; wherein the particle-carrying fluid carrying the anti-channeling pack-off particles passes through holes in the perforated pipe and enters into an annular space between the perforated pipe and the borehole wall, the anti-channeling pack-off particles are accumulated both in the annular space between the flow control filter string and the perforated pipe and in the annular space between the perforated pipe and the borehole wall, so that the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with and full of the anti-channeling pack-off particles;
3) closing the annular space full of the anti-channeling pack-off particles between the flow control filter string and the perforated pipe, and closing the pack-off medium in the annular space between the perforated pipe and the borehole wall;
4) disengaging the running string which is connected to the flow control filter string; and forming a well completion structure in which the annular space between the flow control filter string and the perforated pipe and the annular space between the perforated pipe and the borehole wall are filled with the anti-channeling pack-off particles.
The particle-carrying fluid carrying the anti-channeling pack-off particles is water or aqueous solution.
The anti-channeling pack-off particles may be high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.4 g/cm 3 .
The anti-channeling pack-off particles may be high molecular polymer particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.94 g/cm 3 to 1.06 g/cm 3 .
The anti-channeling pack-off particles may be high-density polyethylene particles with an average particle size ranging from 0.1 mm to 0.5 mm and a density ranging from 0.90 g/cm 3 to 0.98 g/cm 3 .
The anti-channeling pack-off particles may be styrene and divinylbenzene crosslinking copolymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.96 g/cm 3 to 1.06 g/cm 3 .
The anti-channeling pack-off particles may be polypropylene and polyvinyl chloride high molecular polymer particles with an average particle size ranging from 0.05 mm to 1.0 mm and a density ranging from 0.8 g/cm 3 to 1.2 g/cm 3 .
Although the present application has been described with reference to the preferred embodiments of the present application, it should be understood that, the present application is not limited to the disclosed embodiments or structures. On the contrary, it is intended that the present application covers various modifications and equivalent solutions. In addition, various elements of the present application disclosed herein are shown in various exemplary combinations and structures, but other combinations and structures including more or less elements or only one element are also deemed to fall into the protection scope of the present application. | A method and a system for segmental flow control in an oil-gas well are disclosed. The oil-gas well includes a first annular space ( 111 ) and a second annular space ( 103 ). The first annular space ( 111 ) is formed with the space between the borehole wall ( 101 ) of the oil-gas well and a perforated tube ( 102 ) which is in the oil-gas well and extends along an axial direction of the oil-gas well; The second annular space ( 103 ) which is formed with the space between the perforated tube ( 102 ) and a flow-control filter string ( 105 ) which is in the perforated tube ( 102 ) and extends along the axial direction of the oil-gas well. The method includes filling anti-channeling isolating particles ( 109 ) in the first annular space ( 111 ) and the second annular space ( 103 ) to enable fluid to flow in the first annular space ( 111 ) and the second annular space ( 103 ) filled with the anti-channeling isolating particles ( 109 ) in the manner of seepage. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a method for determining basic values from a specimen of a dielectric material for analysis of its vulcanization characteristic and an apparatus for carrying out the method.
Polymers belong to the group of vulcanizable materials and the electric properties thereof have been the subject of relatively comprehensive studies and research for the major part of this century. These studies and research work have generated a great amount of knowledge about the interior structure of polymeric materials and how this is influenced by admixture of different additives such as plasticizers and organic or inorganic fillers. Dielectric measuring methods have also been used to a certain extent in studies of aging phenomena of polymeric materials. Controlling the vulcanizing or curing processes by means of the changes in the dielectric properties i.e. caused by cross-linking or curing reactions is not used much in practice and is nearly not used at all in rubber working technology.
At present the dielectric properties of different polymers are of interest in polymer working only because the dielectric losses can be utilized for generation of heat in connection with preheating or vulcanizing.
Despite the fact that the very earliest work in this special technique, below called vulcametry, was carried out as early as the end of the 1920's, the dielectric measuring methods have not yet had any real importance in vulcametry. This is partly because suitable measuring electrodes as well as directly recording measuring bridges have been lacking. However, the most obvious reason seems to be that the basic mechanisms about the influence of the crosslinking reactions on the dielectric relaxation phenomena are not yet known enough to be used in practical vulcametry.
As is well-known, a dielectric usually contains polarizable or polarized molecules or molecule groups having permanent or induced dipoles. In an electric field the dipoles are turned in the field direction and molecules containing permanent dipoles tend to orientate themselves in electric fields. How fast and to which extent this orientation takes place has to do with how the molecules interfere with each other. When a rubber material is vulcanized--crosslinked, a series of other side reactions except crosslinkages are formed in normal cases which are characteristic of each combination of rubber and vulcanizing agent. The formation and development of these reactions and reaction products can be followed by the aid of dielectric measuring methods. Thus, the dielectric vulcametry and consequently this invention are based on these changes in the polar properties of the vulcanized rubber.
A method developed about 1953 and described in U.S. Pat. No. 3,039,297 for continuous measurement of the crosslinking reaction in rubber mixtures is described in U.S. Pat. No. 3,039,297. This method can be said to be the start of modern vulcametry and is characterized in broad outline in that a continuous or periodic motion or force (tensile, compressive, shearing or torsional) is applied to a test specimen of unvulcanized rubber under simultaneous measurement of force and motion response, respectively. The force/movement is usually transferred to the test specimen by means of a rotor or a linearly movable paddle.
This method was accepted very rapidly and has become very popular which has generated a long series of different measuring apparatuses, which include "the Wallace-Shawbury Curometer", below called curometer, "the Cepar-Apparatus", "Viscurometer", "Vuremo", Zwick-Schwingelastometer" and that most known of all, viz. the so-called Monsanto-Rheometer, below called rheometer.
The original purpose of the technique here called vulcametry was quite simply to produce a functioning control method in the synthetical rubber industry rapidly growing in the post-war period. The vulcametry has thereafter also been found to be a very useful method for studying the reaction kinetics of the vulcanization process and has also been used for this purpose. However, in later years some criticism has been directed to this so-called traditional vulcametry which can be said to be mechanical. It has been shown that if the test specimen is heated relatively slowly and even after reaching temperature of equilibrium there are temperature gradients through the test specimen, that a non-desired sliding can arise between cavity and rotor and paddle, respectively, and that certain rubber materials have a tendency to become porous during the testing procedure.
Certain comparative studies with isothermal vulcanization which are considered to give acceptedly true values are described in Polymer Testing Vol. 1, No. 4, page 247, 1980 by R H Norman. It has also been shown that the rheometer gives a much longer vulcanization time than the curometer which, in turn, gives longer vulcanizatioin times than isothermal vulcanization. Examples of this are shown in the table below which indicates 90% of vulcanization time in seconds at different temperatures.
______________________________________Temperature °C. Isothermal vulc. Curometer Rheometer______________________________________120 3 120 4 800 7 800140 870 1 100 1 800160 280 320 460180 72 105 195200 17 47 97______________________________________
The great differences at low temperatures apparent from the table are unexpected and are propably due to the fact that there is a considerable difference between the true average temperature of the test specimen and the measured temperature even after a very long period of time. On the other hand, the great difference at high temperatures is not directly unexpected. It has been shown that the rheometer in comparison with guaranteed isothermal conditions gives vulcanizing times that are about twice as long at most temperatures. There are two probable explanations of these substantial deviations. Firstly, heat is continuously lost as heat is diverted from the rotor via the rotor shaft to the drive unit of the rheometer, with the result that the rotor becomes colder than the rotor cavity. Due to this the average temperature of the rubber specimen will be considerably longer than the adjusted temperature and therefore the vulcanization process will proceed more slowly. Secondly, it will take a longer time to heat the specimen in a rheometer in comparison with the conditions prevailing when producing the isothermal results shown in the above table due to the fact that the test specimen in the rheometer is much thicker than 0.5 mm which is the thickness of the specimen used in the isothermal tests.
Another disadvantage of conventional vulcametry is the interpretation problems arising when data produced by the rheometer are to be used to determine vulcanization times of voluminous rubber products such as big rubber dampers, contract tires, mill linings etc. Therefore there is a great demand for a method or process enabling measurement of the vulcanization course directly during the vulcanization of the current products.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to provide a method and an apparatus for carrying out the method enabling measurement of vulcanization course directly during the vulcanization in a quick and safe manner and giving true measured values as a result.
This object is achieved by the method and the apparatus of the present invention which measures the relative permittivity ε' r and dielectric loss factor ε" of the rubber as a function of the time at a frequency of at least 10 kHz and preferably at a higher frequency. For instance between 200 and 300 kHz, while rubber is vulcanized at an elevated temperature, for instance between 120° and 190° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically and in the form of blocks an apparatus of the invention for carrying out the method,
FIG. 2 is a plane view of a specimen carrier according to the invention,
FIG. 3 shows examples of structures formed between molecule chains and on these in vulcanization,
FIG. 4 shows a circular, plane-parallel capacitor of the type obtained in a process of the invention,
FIG. 5 shows an equivalent diagram or circuit of said capacitor,
FIGS. 6a, 6b and 6c show how dipoles and ions orientate themselves in a material to which an electric voltage has been applied,
FIG. 7 shows an equivalent diagram of a capacitor containing a dielectric having a high leakage and a tendency to form blocking layers,
FIGS. 8-14 show different curves, that is to say so-called dielectric curo- or vulcograms, of ε' or Δε' as a function of the time at different temperatures and frequences of different rubber mixtures and
FIGS. 14-25 show additional curves for illustrating the invention, these curves being defined more in detail in the specification.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Vulcanization does not proceed in general as a simple chemical reaction but consists of a series of complex reactions that in certain connections may require hours to complete.
Sulphur and substances giving off sulphur are not the only chemical substances participating in these reactions but other substances such as metal oxides, fatty acids and organic accelerators also take part actively in the crosslinking reaction. The organic accelerators do not operate as usual catalysts that do not participate actively in the vulcanizing reaction. The main task of the accelerators is to activate the sulphur and as distinguished from usual catalysts the accelerators undergo chemical changes.
Accelerated sulphur vulcanization is generally considered to proceed according to the following steps described:
(a) The accelerators react with sulphur forming monomeric polysulfides Ac--S x --Ac where Ac is an organic radical formed from the accelerator.
(b) The polysulphides can react with rubber forming polymeric polysulphides of the following structure: rubber--S x --Ac.
(c) The polymeric polysulphides either react directly or via intermedia forming polysulphidic crosslinkages between the rubber molecules according to: rubber--S x --rubber.
Examples of the multiplicity of structures formed between the molecule chains (intermolecularly) and on the molecule chains (intramolecularly) appear from FIG. 3.
In the general case shown in FIG. 7 not only (a) mono-, (b) di-, and (c) polysulphidic crosslinkages are formed in diene rubbers (i.e. rubbers containing conjugated double bonds) but also (d) sulphidic groups with accelerator fragments in side position, (e) intraemolecular cyclic mono- and (d) disulphides, (g) conjugated dienes and (h) trienes, (i) parallel adjacent crosslinkages, (j) crosslinkages bonded to the same or adjacent carbon atoms, (k) c--c bonds (probably do not exist) and (l) not crosslinked material.
In vulcanization the poly- and disulphidic crosslinkages formed initially undergo a series of maturity reactions.
The polysulphidic crosslinkages and the laterally positioned polysulphidic groups undergo desulphurizing reactions to be reformed to di- and gradually monosulphidic crosslinkages and groups.
Before the final formation of the thermally stable monosulphidic crosslinkages and groups takes place the di- and polysulphidic crosslinkages can undergo thermal reactions, sulphurous products such as cyclic sulphides for instance being formed.
Several of the reactions between sulphur and substances giving off sulphur described above increase the polarity of the network formed. The formation and changes of these polar groups during vulcanization reactions are utilized in accordance with the principles on which the invention is based to follow the vulcanization.
According to the invention the apparatus for these measurements and consequently for determining the required basic values from a specimen of a vulcanizing material to be analyzed comprises a press 1 having a press minimum pressure of 200 kPa and two platens 2 which can be heated and the temperature of which is adjusted by means of a temperature regulator 3 for each thereof. Each platen or heat plate 2 is provided with an electrode plate 4 of aluminum galvanically separated from the associated heat plate 2 by means of a layer 5 of teflon foils. This layer 5 need not be thicker than 1 mm. To the upper electrode plate 4 a thermoelement 6 is connected by means of which the temperature of said electrode plate 4 is measured and the tip of which is placed at a small distance, for instance 0.3 mm, inside the surface of the electrode plate 4. The thermoelement 6 is galvanically separated from the electrode plate 4 by means of a very thin coating of silicone rubber and is connected to a digital thermometer 7 with analog output which, in turn, is connected to the temperature input T of a 3-pen writer 8.
Moreover, each of the electrodes plates 4 is connected to an impedance analyzer 9 by means of which capacity C and dielectric loss coefficient D (tan δ) are determined and which can have a frequency range between 5 Hz and 13 MHz. The impedance analyzer 9 is connected with its outputs to the capacity input C and dielectric loss coefficient input D of the 3-pen writer.
The apparatus also includes a specimen carrier 10 consisting of a ring 11 provided with a handle made of an electrically non-conductive material such as teflon with an opening or measuring cavity 12 therein. The volume of the carrier 10 in which the material specimen is placed is defined after introducing the specimen carrier 10 between the electrode plates 4 of the press 1.
In order to achieve the best possible measuring result in the shortest possible time the material specimen should have the smallest possible volume and thickness and this is obtained in accordance with the invention thanks to the fact that the specimen carrier can be made very thin and even thinner than 0.25 mm. The measuring cavity 12 of the specimen carrier 10 shown in FIG. 2 has for instance a volume only amounting to 0.28 cm 3 . The predetermined volume of the measuring cavity 12 is relatively simple to determine, for instance by weighing the size of the material specimen that it will fill up the measuring cavity 12 exactly in pressing.
In accordance with the invention the empty specimen carrier 10 is placed between the heated electrode plates 4 of the open press 1 after which the press 1 is closed and kept closed until the test specimen 10 has been heated to the current testing temperature. After only a few seconds the specimen carrier 10 will take the temperature of the electrode plates 4, and thereafter the press 1 is opened and a material speciment prepared in advance is placed as fast as possible on the lower electrode plate 4 and as centrally as possible within the measuring cavity 12 of the specimen carrier. The press 1 is thereafter closed again and the air pressure is rapidly increased to the intended value, for instance 200 kPa. This value for the pressure has been found to be sufficient to press out the specimen consisting of unvulcanized rubber so that the specimen will fill up the measuring cavity 12 of the specimen carrier enclosed by the electrode plates 4 completely at the same time as it prevents porosity from arising in the specimen. Thanks to the fact that the pressed-out specimen becomes very thin, for instance 0.25 mm, it is heated very rapidly, i.e. within less than half a second, a time that is so short that it can be completely neglected in comparison with the normally current vulcanization times. As soon as the press has closed the capacity values C, tangent δ-values of dielectric loss coefficient D and temperature values T start to be automatically recorded by the 3-pen writer 8.
Thus, these values derive from the body of vulcanized rubber located within the specimen carrier 10 which body forms together with the two electrode plates 4 a circular, plane-parallel capacitor 13 (FIG. 4). The relative permittivity ε' r and dielectric loss factor ε" of which can be easily calculated by means of the resulting values of capacity and loss angle. It should be noted that no separation films have been used between the electrode plates 4 and the dielectric (the vulcanized rubber) and this is an advantage as such films have been found to give measuring results that are strongly influenced whether the film is charged or discharged through the bulk resistance of the dielectric.
As is well-known, the capacity of a plane-parallel capacitor of the type for instance shown in FIG. 4 is determined by the surface A of the electrode plates and their mutual distance L. A capacitor thus consisting of two electrode plates with the surfaces A having a mutual distance L and containing a homogeneous dielectric, the vulcanized rubber in this case, with the relative permittivity ε' r and loss factor ε" can be described by means of an equivalent diagram or circuit 14 of the type shown in FIG. 5. This circuit is built of the capacitor C p which is connected in parallel with the resistance R. The capacity of C p and the resistance R can be written
C.sub.p =ε.sub.o ε'.sub.r A/L; ε'.sub.r =C.sub.p /C.sub.o Equ. (1)
R=L/w×A×ε"×ε.sub.o Equ. (2)
where
ε o =the vacuum permittivity
ω=the angular frequency
C o =the capacity of an empty capacitor
C p =the capacity of a capacitor containing a dielectric.
By reforming the equations (1) and (2) explicit expressions of ε' r and ε" are obtained. ##EQU1##
ε"=L/ARwε.sub.o Equ. (4)
It is apparent from the equations (3) and (4) that the relative permittivity ε' r is not actuated by the resistive component R while ε" is influenced.
Polymers in general and polymers containing electrically conductive substances such as carbon black in particular can transport charges if an electric voltage is applied across the material (the dielectric), see FIG. 6.
The resistivity of a dielectric and its tendency to form blocking layers at the surfaces of the electrode plates influence the dielectric properties of the material. Dielectrics having a low resistivity are said to have a high leakage.
The equivalent diagram of a capacitor containing a dielectric with a high leakage and having tendencies to form blocking layers is apparent from FIG. 7.
The part of the resistance (R DC ) caused by charge transport is independent of the frequency of the electric field applied across the capacitor as distinguished from the part of the resistance (R p (W)) caused by the dipolar relaxation. If the current through a dielectric is caused by charge migration the resistance of the dielectric can be characterized by its bulk resistivity. The two charged layers formed at the surfaces of the electrode plates have in FIG. 4 been combined to a blocking capacitor C b which is connected in series with the circuit conneted in parallel formed by C p , R p (w) and R DC .
The loss factor ε" can then be written ##EQU2## R DC being the resistance caused by charge transport and R p (w) being the resistance caused by the dipolar relaxation.
The dipolar parallel resistance R p (w) goes towards infinity when the frequence goes towards zero while ε" will increase due to the D.C. conduction when the frequency decreases.
If the conductivity of the dielectric is so high that the impedance of R is less than the impedance R c of C
R.sub.c =L/wAε'.sub.r ε.sub.o Eqv. (6)
ε"/ε' will be tan δ>1 with the result that the charge of C b through R will dominate the electric behaviour of the circuit.
The electrode polarization, i.e. the charge of C b , will not influence the characteristic of the electric circuit as long as R is greater than R c . It can be concluded from this that electrically isolating separation films between the dielectric and the electrode plates, which sometimes have been used in similar connections, should not be used so that these films disturb or usually make correct measurements completely impossible.
The function of the present method and how the measurement results obtained correlate with the corresponding ones from other known and established measuring methods is described more in detail in the following by the aid of some examples.
Example 1 concerning natural rubber mixtures A, B and C with conventional sulphur/accelerator systems and retardants (Santogard PVI-50) and having a composition according to the following table 1:
______________________________________ A B C D______________________________________NR SMR CV 60 100 = = =Carbon black N220 45 = = =Dutrex 729 HP.sup.1 8 = = =ZnO 4 = = =Stearic acid 1 = = =TMQ.sup.2 1.5 = = =6 PPD.sup.3 1.5 = = =Microcrystalline wax 2 = = =CBS.sup.4 0.8 = =Sulphur 2 = =PVI-50.sup.5 -- 0.5 0.8TMTD.sup.6 1DTDM.sup.7 1______________________________________ .sup.1 Aromatic oil .sup.2 Polytrimethyldihydrochinoline .sup.3 Dimethylbutylphenyl-p-phenylene diamine .sup.4 N--cyclohexyl2-benzothiazyl-sulfenamide .sup.5 Cyclohexylthiophthalimide CTP .sup.6 Tetramethylthiuram disulfide .sup.7 4,4dithiomorpholine
The mixtures shown in the table are typical of such mixtures of natural rubber used in industry for the manufacture of for instance automobile tires. The mixtures A, B and C are identical except for the fact that the mixtures B and C contain small amounts--0.5 phr and 0.8 phr, respectively--of a retardant (Santogard™ PVI-50) moving the vulcanization start towards lower times. The mixture D is also identical to the mixture A except for the fact that the coventional sulphur/accelerator vulcanization system in mixture A has been exchanged for an accelerator/sulphur donor vulcanization system. Such systems are generally designated EV-(Efficient vulcanization) systems.
On the basis of the basic values obtained by means of the method and apparatus of the invention different curves can be obtained and a nunber of such curves is shown in FIGS. 8-24. In the following some of these curves are called dielectric curo- or vulcograms showing ε' r as a function of the time at different temperatures and frequencies and for the mixtures A, B and C such curograms are shown in FIGS. 8, 9 and 10.
The dielectric curograms of the mixtures A, B and C have all the same form as in the sense that ε' r decreases initially to start to increase again via a minimum point (ε' r min). The time up to ε' r min is also dependent on the composition of the mixture and temperature in such a way that a higher temperature gives shorter times to ε' r min and that the retarded mixtures (B and C) give longer times to ε' r min than the non-retarded mixture A.
To find inflection points dependent on temperatures, frequency and retardance in the dielectric curograms was unexpected considering the fact that the measuring cavity 12 is filled with a material--a dielectric--having a relative permittivity ε' r being in the range 500-1900 depending on temperature and frequency.
As the capacitance of a plane-parallel capacitor, as previously mentioned, is proportional to the surface of the dielectric and inversely proportional to its thickness it is very important that the geometric form of the dielectric is kept at a constant. Sometimes this has been relatively difficult to accomplish because a small displacement of the position of the rubber specimen in the specimen carrier 10 and small variations of the weight of the specimen may cause the rubber to flow asymetrically in the specimen carrier 10 with the result that part of the rubber will flow out of the specimen carrier on one side at the same time as a waste is formed on the other side or that the specimen carrier is filled either too much or too little. The effect of this is that both the surface and the tnickness of the dielectric can vary a little if a great deal of care is not taken on preparation and placement of the specimen in the specimen carrier 10.
If an analysis method, especially one that is intended for routine analyss, might be accepted it is required that the preparation of the specimen should be simple. To avoid the problem with the ε' r -values being displaced due to the fact that the size and thickness of the dielectric vary a little the measured values can be normalized in the following way. Instead of using absolute values of ε' r Δε' r -values can be calculated by subtracting the lowermost ε' r -value, i.e. the ε' r -value at the inflexion point, from all following ε' r -values.
Δε'.sub.r =ε'.sub.r t≧t inflex. -ε'.sub.r inflex. Equ. (7)
Δε' r is then plotted as a function of the time.
In FIGS. 11, 12 and 13 Δε' r -values calculated according to equ. (7) for the mixtures A, B and C from data recorded at 300 kHz have been plotted as a function of the time at four different vulcanization temperatures.
For the mixtures A, B and C vulcanized at about 140°, 150° and 160° C. the Δε' r -values increase monotonously, especially at the lower vulcanization temperatures. Higher vulcanization temperatures always give a higher initial inclination of the Δε' r -curves than lower temperatures which shows that the inter- and intramolecularly bonded sulphur gives a chemical structure of the network that becomes more polar with higher vulcanization temperature.
At about 170° C. Δε' r increases for the mixtures B and C initially to decrease again via a maximum. At present it is not known why mixture A does not show the same behaviour as B and C at about 170° C. The reason may possibly be that the retardant Santogard PVI-50 included in the mixtures B and C influences the chemical structure of the network.
In order to investigate what the correspondence of the inflection points in the curograms in FIGS. 8, 9 and 10 or the zero-values (Δε' 2 =0) in FIGS. 11, 12 and 13 in the vulcanization of the test specimens, a great number of specimens are vulcanized at the temperatures used at recording of the dielectric curograms. Part of the specimens was vulcanized for a somewhat shorter time or the same time to which the time corresponds necessary to reach the ε' r -minimum or the time to reach Δε' r =0. A larger number of test specimens was vulcanized for longer times than the time necessary to reach the ε' r -minimum. The crosslinkage density of the specimens was determined by swelling the specimens in dichloromethane for 6 days at room temperature, after which the cosslinkage density was calculated by means of Flory-Rehner's equation. The influence of the carbon black on the crosslinkage density has been compensated by means of the correction factors indicated by Kraus (12).
The change of the crosslinkage density as a function of the vulcanization temperature and the time is shown in FIGS. 14, 15, 16 for the mixtures A, B and C.
The results obtained are typical of natural rubber that has been vulcanized by means of conventional sulphur vulcanization systems in the sense that the maximum crosslinkage density will decrease when the vulcanization temperature increases, as is apparent from FIG. 17.
The rate at which the number of effective crosslinkages decreases as a function of the vulcanization temperature over a large temperature range (140° C.-200° C.) of a typical sulphur-vulcanized natural rubber mixture is also shown in FIG. 17. Data for this later curve has been taken from Gummi Asbest Kunststoffe 34, page 124, 1981, E. R. Rodger.
As is apparent from the figures the agreement between the times up to the start of the vulcanization which has been determined chemically (FIGS. 14, 15 and 16) and the times up to the ε' r -minimum values determined dielectrically (FIGS. 8, 9, 10 and 11, 12, 13) is very good.
In addition to correctly indicating the start of the vulcanization the dielectric method has also been found to give valuable information about the degree of vulcanization. In FIG. 18 the times up to t 50 , i.e. the time necessary to reach 50% of full vulcanization measured chemically, on one hand--t 50 chem (min)--and by the rheometer--t 50 rheometer--, on the other hand have been plotted as a function of t 50 diel.
In general it can be observed that the Monsanto rheometer gives longer t 50 -times than the isothermally determined t 50 chem and t 50 diel times. These results agree well with those previously indicated in so far as the Monstanto rheometer gives longer vulcanization times than measuring methods operating under isothermal conditions.
Example 2 concerning natural rubber mixture D with EV-vulcanization systems.
As previously mentioned and as also apparent from the previous table, the conventional sulphur/accelerator system in mixture A has been exchanged for an accelerator/sulphur donor system in mixture D.
In FIG. 19 dielectric curograms for mixture D are shown taken at 300 kHz and about 130°, 140°, 150° and 160° C. ε' r as a function of the time shows the same initial course as for the mixtures A, B and C, i.e. ε' r first decreases. As distinguished from the mixtures A, B and C the curogram of mixture D has two inflection points marked by whole arrows (ε' r min) and dashed arrows (ε' r max) in FIG. 19.
In FIG. 20 Δε' r is shown as a function of the vulcanization time. The inclination of the left sides of the loops and the maximum value of Δε' r max are increased when the vulcanization time is increased. The width of the loops increases when the vulcanization temperature is reduced.
In FIG. 21 the chemically determined crosslinkage density of mixture D is shown as a function of vulcanization temperature and time. The maximum crosslinkage density at different vulcanization temperatures varies much less than for the mixtures A, B and C which is in good agreement with previously known results.
In FIG. 22 tΔε' r max diel (marked by dashed arrows in FIG. 19) has been plotted as a function of t 50 chem (min) and t 50 rheometer (min) in the same way as in FIG. 18.
It is apparent from FIGS. 19 and 21 that the vulcanization start ε' r min (see also Δε' r =0 in FIG. 20) well coincides with the vulcanization start determined chemically (FIG. 21) while ε' r max is well correlated with t 50 chem (min) which has been plotted in FIG. 22 together with t 50 rheometer (min).
In the same way as for mixtures A, B and C the rheometer also gives longer vulcanization times for mixture D than for the isothermal methods.
Example 3 concerning mixtures F, G, H and I of natural rubber with conventional sulphur/accelerator systems and with a varying amount of sulphur.
If a measuring technique should be of any value for i.e. mixture development and/or routine testing of rubber mixtures the method should be able to detect not only big changes in the vulcanization characteristic exemplified by mixture A-D but also be able to detect small changes such as small variations in the sulphur content. In order to investigate the ability of the dielectric method to detect variations of rubber mixtures that might be designated as normal mixture to mixture variations which may arise under industrial conditions the mixtures shown in the following table 2 were investigated.
______________________________________ F G H I______________________________________SMR CV 60 100 = = =ISAF N220 45 = = =Dutrex 729 HP 8 = = =ZnO = = = =Stearic acid 1 = = =TMQ 1.5 = = =6 PPD 1.5 = = =Microcrystalline wax 2 = = =CBS 0,8 = = =Sulphur 1.5 2.0 2.5 3.0______________________________________
Concerning abbreviations, see table 1.
Dielectric curograms (Δε' r as a function of the time) for the mixtures F-I recorded at 300 kHz and the temperatures 140° and 160° C. are shown in FIGS. 23 and 24.
Δε' r as a function of the time has, as is expected, the same form as the curves previously reported in FIG. 11, i.e. Δε' r increases the whole time monotonously for the curograms recorded at 140° C. while Δε' r of the curograms recorded at 160° C. of the two lowermost sulphur contents (1.5 and 2.0 phr.S) reaches a constant Δε' r -value more quickly the lower the sulphur content is.
As is apparent from FIGS. 23 and 24 Δε' r is very sensitive to the amount of sulphur in the mixture--more sensitive the higher the vulcanization temperature is.
The following general conclusions can be drawn from the dielectric curograms shown in FIGS. 23 and 24.
(a) An increased amount of sulphur and increased temperature will result in that Δε' r increases faster than if the sulphur content and the temperature are low. This agrees well with what is previously known about the network structure of the sulphur vulcanized natural rubber in the sense that high sulphur contents in combination with high vulcanization temperature generate a polar network which is reflected here in the form of increasing capacity.
(b) The start of vulcanization is detected quite correctly by means of the dielectric method as compared with the chemically determined crosslinkage densities of mixtures F and I shown in FIG. 25. When the sulphur content is reduced the start of the vulcanization is moved towards longer times which agrees well with the results obtained by means of the Monsanto Rheometer, however with the essential difference that the dielectric results, as a consequence of the completely isothermal conditions under which these are recorded, are displaced towards shorter times, which is apparent from the tables in FIGS. 23 and 24.
(c) The Δε' r -curves reach constant values more quickly the lower the sulphur content is and the higher the temperature is, as is shown in FIGS. 23 and 24.
Dielectric vulcametry, i.e. in-situ measurements of how the dielectric properties of vulcanizing rubber are changed as a function of vulcanizing time and temperature has been found to give valuable information about the start of the vulcanization and the degree thereof. Dielectric vulcametry has turned out to be a powerful tool in mixture development because the method has a high sensitivity to minimal changes in the concentration of e.g. vulcanizing agent, accelerators and retardants.
Another advantage of the dielectric method as compared with previously known analysis techniques--mechanical rheometers--is that the amount of test material required per analysis is very small (less than 0.5 g) with the result that the analysis can be carried out under quite isothermal conditions because the test material can be heated to the predetermined temperature in less than one second.
Another advantage of the dielectric technique is that it opens the possibility of measuring the course of vulcanization directly in the vulcanized products by using the multi-channel electrode described in Swedish patent application 8501270-6.
The invention is not restricted to what has been described above and shown in the drawings but can be changed and modified in several different manners within the scope of the inventive thought defined in the claims. | A method and an apparatus for determination of basic values from a material specimen to analyze the vulcanization characteristic of the material and to enable measuring of a vulcanization process during the vulcanization in a rapid and safe manner. According to the method the specimen is shaped with resulting true measured values under pressure and at a temperature preferably in excess of 100° C. to a predetermined form and thickness between two electrodes with plane-parallel sides facing each other which during the shaping process are brought into an intimate contact with the shaped body to form together a capacitor, the capacitance and loss angle of this capacitor being measured and recorded together and simultaneously with the temperature of at least one of the two electrodes as the basic values. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a power converter having an output current detecting function, and particularly a power converter suitable for a servo system, a DC/DC converter, a three-phase AC inverter, etc.
[0003] 2. Description of the Related Art
[0004] It is usually the case that in order to control a power converter for a servo system, a DC/DC converter, a three-phase AC converter or the like, it is required to detect the output current thereof, and thus various kinds of current sensors have been proposed. In this case, an insulating type current sensor having a core, so-called a hall sensor is known. Here, in the hall sensor, a conductor through which current to be measured flows is made to penetrate through a ring-shaped core, and magnetic field occurring by the current is read out by a hall sensor disposed in the magnetic path of the core, thereby detecting the current.
[0005] In addition to the hall sensor described above, there has been also hitherto known a shunt resistance type current sensor in which a shunt resistor is inserted in the passage of the current to be measured and a voltage drop appearing in the shunt resistor is detected (for example, see JP-A-2003-61392). Furthermore, there has been also hitherto known a current detecting method for observing an ON-voltage of MOSFET used as a switching device in a power converter for use in a field chopper circuit of a servo system or an electric motor control device and converting the observed ON-voltage to a current value (for example, see JP-A-2004-48863).
SUMMARY OF THE INVENTION
[0006] A current sensor used for a power converter is generally required to be compact in size and low in loss and cost, and also high in precision. The conventional techniques as described above have not paid sufficient attention to these points.
[0007] In the above conventional techniques, the current sensor having the insulating core is expensive in price, and also requires a structure such as a bus bar penetrating through the sensor or the like as a passage for primary current. Therefore, the number of parts is increased, and the size of the structure is increased, so that the cost further rises up.
[0008] Furthermore, from the viewpoint of the system protection to over-current such as short-circuit or the like, it is required to provide a current detecting circuit for detecting the over-current of the switching device separately from the current sensor for detecting the output current. Accordingly, increase of the number of parts and further increase in cost are unavoidable.
[0009] Still further, the current sensor based on the shunt resistor brings a great power loss to large-current controlling equipment such as a power converter or the like, and thus the resistor for shunt is increased in size. In addition, it is required to pay attention to suppression of temperature increase due to heating, so that the large-size design and the cost-up are unavoidable.
[0010] From these viewpoints, a hopeful view has been taken on the current detection technique using the ON-voltage of MOSFET among the above-described techniques. In this case, however, the switching device is required to be turned on at the current detecting timing, and thus the period of the current detection and the ON-OFF duty cycle are restricted by each other.
[0011] For example, when current is detected by an lower arm, the lower arm is required to be perfectly turned on every current detection period, and it is impossible to detect current under the state that an upper arm is turned on by 100%. Furthermore, it takes a time from the turn-on time of the lower arm till the time when the output of the current value is stabilized, and also it takes a time to sample the current value, so that it is required to increase the ON-period of the lower arm, and the restriction to the duty of the upper arm is more remarkable.
[0012] As described above, when the duty has an upper limit value, the output voltage performance of the power converter is restricted, and for example in the case of an inverter for driving a three-phase motor, there occurs a demerit that the voltage applied to the motor is restricted and thus current cannot be made to flow at high rotation.
[0013] An object of the present invention is to provide a low-cost power converter that is compact in size and low in loss and can perform current detection with no restriction in output voltage performance.
[0014] In order to attain the above object, a power converter having an upper arm switching device (high side switching device) and a lower arm switching device (low side switching device) that are connected in series between a positive power supply terminal and a negative side power supply terminal for direct current, the connection point between the upper arm switching device and the lower arm switching device being set as an output terminal, wherein each of the upper arm switching device and the lower arm switching device is constructed by a switching device having a mirror device (current mirror device), the power converter is further equipped with an upper arm current detecting unit for detecting current flowing in the mirror device of the upper arm switching device and a lower arm current detecting unit for detecting current flowing in the mirror device of the lower arm switching device, and a signal detected by the upper arm current detecting unit and a signal detected by the lower arm current detecting unit are differentiated from each other (i.e., the difference between both the signals is taken) and set as a current value of the output terminal.
[0015] The above converter may be equipped with an over-current protecting unit that is operated by using at least one of the signal detected by the upper arm current detecting unit and the signal detected by the lower arm current detecting unit, whereby the same object as described above can be attained.
[0016] Furthermore, the power converter described above may be mounted in a vehicle, whereby the same object as described above can be attained.
[0017] A method of detecting mirror current may be a method of reading the mirror current by an insulating type current sensor, or a method of making mirror current flow through a shunt resistor and reading a voltage across both the ends of the shunt resistor.
[0018] According to the present invention, the difference in current between the upper arm and the lower arm is read in, and thus current can be detected even when only the upper arm is set to 100% ON-state or only the lower arm is set to 100% ON-state. As a result, a current sensor which is high in precision, compact in size and low in loss can be achieved without restricting an application range.
[0019] According to the present invention, the high-precision current control can be achieved, and thus a power converter having excellent current control performance can be provided in low cost. By mounting this power converter in a vehicle, a vehicle having high performance can be manufactured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram showing a first embodiment of a power converter according to the present invention;
[0021] FIG. 2 is a block diagram showing a second embodiment of the power converter of the present invention; and
[0022] FIG. 3 is a block diagram showing a third embodiment of the power converter of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Preferred embodiments of a power converter according to the present invention will be described hereunder with reference to the accompanying drawings.
First Embodiment
[0024] FIG. 1 shows a first embodiment in which the present invention is applied to a switching circuit used in a field chopper circuit or an electric motor control device as disclosed in JP-A-2004-48863 described above.
[0025] In the first embodiment, a switching device 1 serving as an upper arm and a switching device 2 serving as a lower arm are connected in series between a positive terminal and a negative terminal to which a DC voltage VB is applied from a DC power source 3 , and current IU and IL flowing through the respective elements respectively are switched, whereby output current IO is supplied from an output terminal 0 to a load (not shown) such as a motor or the like.
[0026] Each of the switching devices 1 , 2 is equipped with a gate driving circuit 4 , 5 , and subjected to switching control under the control of a control operating unit 6 . At this time, the output current IO of an accurate value cannot be supplied to a load such as a motor or the like at any time unless the control operating unit 6 controls the switching timing and the switching time of each of the respective switching devices 1 and 2 in accordance with the detection result of the output current IO. Therefore, as described above, the output current IO must be detected and controlled.
[0027] Therefore, according to this embodiment, as each switching device 1 ( 2 ) is used MOSFET in which a main switching device 1 - 1 ( 2 - 1 ) of MOSFET is provided with a mirror device 1 - 2 ( 2 - 2 ) of MOSFET, that is, a so-called mirror device appended MOSFET. Here, MOSFET is an electric field effect transistor (FET) of metal oxide semiconductor (MOS).
[0028] Under the state that the mirror device appended MOSFET is used as the switching device, the mirror device 1 - 2 ( 2 - 2 ) of each switching device 1 ( 2 ) is provided with a current detecting circuit 7 ( 8 ), and the current flowing through the mirror device 1 - 2 ( 2 - 2 ), that is, mirror current IU M (IL M ) is detected by the current detecting circuit 7 ( 8 ). The detection result is taken out as a detection signal S IU (S IL ), and input to a comparison circuit 9 .
[0029] In the comparison circuit 9 , the input detection signals S IU and S IL are differentiated from each other, and the difference result is output as a differential signal S IO . This differential signal S IO is input to the control operating unit 6 , and the switching timing and the switching time of each of the switching devices 1 and 2 are controlled on the basis of this signal as a signal representing the output current IO.
[0030] At this time, the output current IO is represented by the difference between the current IU flowing through the switching device 1 of the upper arm and the current IL flowing through the switching device 2 of the lower arm. Accordingly, as described above, the output current IO can be represented by the differential signal S IO output from the comparison circuit 9 , so that the output current IO can be controlled by supplying the differential signal S IO corresponding to the difference between the detection signal S IU and the detection signal S IL to the control operating unit 6 .
[0031] Here, it is general that the control operating unit 6 is designed so as to be equipped with a microcomputer and the control is carried out by the microcomputer. In this case, as shown in FIG. 1 , the input of the output current IO to the microcomputer may be based on a system of inputting the outputs of the current detecting circuits 7 and 8 to a comparison circuit 9 comprising a differential amplifier and then inputting a differential voltage to the AD port of the microcomputer. In place of this system, the processing of directly inputting the detection signal S IU of the current detection circuit 7 and the detection signal S IL of the current detection circuit 8 to the AD port of the microcomputer and determining the differential voltage by software of the microcomputer may be executed.
[0032] In this case, an insulating type current sensor having a core, a so-called hall sensor is used as each of the current detection circuit 7 , 8 as shown in FIG. 1 while these sensors are symbolized. As described above as the prior art, according to this sensor, a conductor serving as a passage through which current to be measured flows is made to penetrate through a ring-shaped core, and magnetic field induced by the current is read out by the hall sensor disposed in the magnetic path of the core and detected as the current. Accordingly, the size of the hall sensor is greatly dependent on the maximum value of the current to be detected.
[0033] Now, it is assumed that the maximum values of the current IU, IL flowing through the respective switching devices 1 and 2 are equal to 500 A, for example. In this case, a bus bar type conductor having a remarkably large cross section area is required as the conductor serving as the passage for current, and thus the core is also large in size, so that the whole sensor is also large in size and the cost is increased.
[0034] However, at this time, the current flowing through the mirror device 1 - 2 ( 2 - 2 ) of each switching device 1 ( 2 ) corresponds to the mirror ratio of the switching device concerned. If the mirror ratio is 1000:1, the mirror current IU M , IL M in the above case is merely 0.5 A even at maximum.
[0035] Accordingly, in this case, it is sufficient to merely insert a remarkably narrow conductor into the core. For example, it is sufficient even if an electric wire used for wiring is made to directly penetrate through the core or wounded by several turns, and also the core itself can be designed in a remarkably small size. Therefore, in this case, the compact-size and low-cost design can be easily performed.
[0036] In addition, the mirror ratio of the mirror-appended MOSFET is determined by the electrode area of the main element and the mirror device. Accordingly, from the viewpoint of the recent semiconductor manufacturing technique, it is normal that the electrode area can be easily set to a remarkably accurate value and also stabilized. This is not limited to the mirror-appended MOSFET, but also other mirror device appended switching devices, for example, mirror-appended IGBT.
[0037] Accordingly, according to the first embodiment, In addition to the miniaturization of the current detecting circuits 7 and 8 and the reduction of the cost, the precision can enhanced, so that a power converter having excellent performance can be easily provided with greatly reducing the cost.
[0038] Furthermore, according to the first embodiment, hall sensors, that is, insulating type current sensors are used as the current detecting circuits 7 and 8 . As a result, they can be used with paying no attention to the potential difference between the upper arm switching device 1 and the lower arm switching device 2 , and thus there is a merit that a circuit for voltage isolation is not separately required.
[0039] Still furthermore, in the first embodiment, the current detecting circuit 7 , 8 is individually provided to each switching device 1 , 2 . Therefore, if the detection signal S IU is input from the current detection circuit 7 to the gate driving circuit 4 while the detection signal S IL is input from the current detection circuit 8 to the gate driving circuit 5 , and a gate signal output from each of the gate driving circuits 4 , 5 is narrowed down when these signals exceed a predetermined threshold value, thereby interrupting the switching devices 1 , 2 , the switching device would be provided with an over-current protection function. Accordingly, the output terminal can be protected from short to power, short to ground, etc.
Second Embodiment
[0040] Next, a second embodiment of the present invention will be described with reference to FIG. 2 .
[0041] In the second embodiment, mirror current is detected by a shunt resistor. Accordingly, as shown in FIG. 2 , shunt resistors 10 , 11 are inserted in the current paths of the respective mirror devices 1 - 2 and 2 - 2 , and differential circuits 12 and 13 are connected to the shunt resistors 10 , 11 in parallel. The other constituent elements are the same as the first embodiment shown in FIG. 1 .
[0042] First, the shunt resistor 10 causes a voltage drop based on the mirror current IU M of the mirror device 1 - 2 , and the differential circuit 12 acts to detect the voltage drop and achieve a detection signal S IU representing the current IU flowing through the switching device 1 of the upper arm. The shunt resistor 11 causes a voltage drop based on the mirror current IL M of the mirror device 2 - 2 , and the differential circuit 13 acts to detect this voltage drop and achieve a detection signal S IL representing the current IL flowing in the switching device 2 of the lower arm.
[0043] Therefore, as shown in FIG. 2 , the detection signals S IU , S IL are input to the comparison circuit 9 to output a differential signal S IO , and the differential signal S IO is input to the control operating unit 6 , whereby the output current IO can be controlled with high precision as in the case of the first embodiment shown in FIG. 1 .
[0044] Here, in the case of the second embodiment, the shunt resistors 10 , 11 are also inserted in the current paths of the mirror devices 1 - 2 and 2 - 2 . Accordingly, the current flowing through each shunt resistor 10 , 11 is remarkably smaller than the current IU, IL flowing through each switching device 1 , 2 .
[0045] For example, in this case, assuming that the maximum value of the current IU, IL flowing through the switching device 1 , 2 is equal to 500 A and the mirror ratio is equal to 1000:1, the mirror current IU M , IL M is also equal to 0.5 A at maximum. The loss P at this time is proportion to the square of the current I.
[0046] Accordingly, according to the second embodiment, the loss based on the shunt resistors 10 , 11 can be suppressed to a sufficiently small level, and thus heating is also suppressed by the amount corresponding to the suppressed level of the loss, so that the resistor can be miniaturized. As a result, according to the second embodiment, in addition to the miniaturization of the current detection circuits 7 , 8 and the reduction of the cost, the precision can be enhanced, so that a power converter having excellent performance can be easily provided with greatly reducing the cost.
[0047] In the case of the embodiment shown in FIG. 2 , with respect to the shunt resistor 10 constituting the voltage detecting circuit of the upper arm, the potential thereof is not fixed to zero, and also it varies from 0V to VB in accordance with the switching of the switching device 1 of the upper arm.
[0048] Accordingly, in the second embodiment, it is needless to say that the potential of the shunt resistor 10 is required to be level-shifted to the same potential as the potential of the switching device 2 of the lower arm or the control operating unit 6 by using a differential amplifier or an isolation amplifier.
Third Embodiment
[0049] Next, a vehicle in which the power converter of the present invention is mounted will be described as a third embodiment with reference to FIG. 3 . In this case, the vehicle according to the third embodiment is illustrated as a car 100 , and it uses an engine 110 such as a gasoline engine or the like as a power source, for example.
[0050] When the car 100 travels, the torque of the engine 110 is transmitted to wheels WH 1 , WH 2 through a transmission device T/M and a differential gear mechanism DEF. At this time, an M/G (dynamotor) 111 is connected to the engine 110 , and M/G 111 is operated as a normal alternator, and also operated as a starter for the engine 110 .
[0051] Accordingly, M/G 111 operates as the alternator (AC generator) when the engine 110 is rotating, and two secondary batteries of a main battery 120 having a terminal voltage of 36V and an auxiliary battery 121 having a terminal voltage of 12V are charged. At the start time of the engine 110 , AC power is supplied from the main battery 120 to M/G 111 , and M/G 111 is operated as the AC generator so that starting torque is supplied to the engine 110 .
[0052] Therefore, INV (inverter device) 130 is connected to M/G 111 . When M/G 111 is operated as the alternator, INV 130 is made to carry out a forward conversion operation to convert AC output of M/G 111 to DC output, so that the main battery 120 and the auxiliary battery 121 are charged. When M/G 111 is operated as the AC generator, INV 130 is made to carry out a normal reverse conversion operation to convert the DC output of the main batter 120 to three-phase AC power, and the three-phase AC power is supplied to the M/G 111 , so that a torque necessary to start the engine 110 is generated.
[0053] At this time, in the case of a normal car, various kinds of electrical components such as lights, etc. are designed in conformity with specifications of a DC voltage of 12V, and thus the auxiliary battery 121 is mounted in the car to operate these electrical components. Accordingly, in order to charge the auxiliary battery 121 , a DC/DC (DC/DC converter) 122 whose output voltage is based on 36V/12V specification is provided, and the auxiliary battery 121 is connected to INV 130 through the DC/DC 122 .
[0054] In the embodiment shown in FIG. 3 , the power converter according to the first embodiment or the second embodiment is applied to INV 130 , and the mirror-appended switching device is used for PD (power device) 131 serving as a main circuit element of INV 130 . This is the feature of this embodiment. As a result, high-precision current control can be performed by the miniaturized and cost-reduced INV 130 .
[0055] Furthermore, the power converter according to the first embodiment or the second embodiment may be applied to DC/DC 122 , and the mirror-appended switching device may be used for the switching device of the power converter. In this case, DC/DC 122 can be also miniaturized and the cost thereof can be reduced. Furthermore, high-precision current control can be performed.
[0056] At this time, PD 131 is controlled from a microcomputer 134 through an interface 133 by a driving circuit 132 in INV 130 . The microcomputer 134 is controlled by a further superordinate CU (control unit) 200 for collectively controlling the overall car 100 .
[0057] As described above, by applying the power converter of the first embodiment or the second embodiment to INV 130 , DC/DC 122 , etc., the current sensor that is high in precision, compact in size and low in loss and cost can be provided to a power converter for a car. Furthermore, for example, when a rectangular-wave based operation is carried out by an inverter or the like, according to the embodiments of the present invention, the current detection can be performed even under the state that any one of the arms is set to 100%-ON. As a result, the voltage utilization factor can be enhanced, and high-output driving can be performed by even a compact motor. Therefore, the weight of the vehicle can be reduced.
[0058] Here, M/G 111 is operated at the AC generator at the start time of the engine as described above. However, it can be operated as an electric motor even when the vehicle runs. Accordingly, in place of the engine 110 , it may be used as a driving source for a car or it may be used as an auxiliary driving source to make a car run together with the engine 110 . | A power converter having a high side switching device and a low side switching device that are connected in series between a positive power supply terminal and a negative side power supply terminal for direct current, the connection point between the high side switching device and the low side switching device being set as an output terminal, and each of the high side switching device and the low side switching device being constructed by a switching device to which a current mirror device is appended, further including a high side current detecting unit for detecting current flowing in the current mirror device of the high side switching device, and a low side current detecting unit for detecting current flowing in the current mirror device of the low side switching device. A signal detected by the high side current detecting unit and a signal detected by the low side current detecting unit are differentiated from each other and set as a current value of the output terminal. | 7 |
This is a continuation of application Ser. No. 07/335,203, filed Apr. 7, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of synchronization control in computer systems.
2. Description of Related Art
The closest art known to the Applicant is embodied in the Intel 80386 tm ('386 tm ) microprocessor manufactured by Intel Corporation of Santa Clara, Calif.
In general, computer systems utilizing the '386 microprocessor embody a number of components, such as the '386 microprocessor, a math coprocessor (typically either the 80287 or 80387 numeric coprocessor), etc. In computer systems utilizing the '386 processor, the general purpose microprocessor (i.e., the '386) and the math coprocessor are separate, discrete components.
The architecture of the '386, as in many general purpose processors, includes synchronization instructions; such synchronization instruction allow for synchronization of processing between components in a computer system utilizing the '386. Further, synchronization instruction may provide means for initiating error checking.
For example, the WAIT instruction in the '386 instruction set causes the '386 to wait execution until a numeric coprocessor (such as the 80287 or 80387) has finished a task. In general, the numeric coprocessor activates a BUSY pin. When the BUSY pin is active (brought low in the '386), the WAIT instruction suspends execution of '386 instructions until the BUSY pin is inactivated (brought high). In this way, processing on the '386 microprocessor may be suspended to guarantee that a numeric instruction being processed by the numeric coprocessor has completed execution.
It is desired to develop a method for removing (or ignoring during execution) synchronization instructions from an instruction sequence in computer systems.
Specifically, it is desired to develop a system for speeding up the execution of an instruction sequence by removing, under certain conditions, wait states created by synchronization instructions.
SUMMARY OF THE INVENTION
A method for speeding up the execution of an instruction sequence in a computer system implementing functions of a general purpose processing unit and a special purpose processing unit under common control is described. The method eliminates certain created by synchronization instructions.
The method involves the steps of detecting that a synchronization instruction has been encountered during the execution of an instruction sequence and replacing or substituting for the synchronization instruction a null instruction. In the preferred embodiment, a one clock cycle no-operation instruction is utilized as the null instruction.
The microprocessor of the preferred embodiment comprises an instruction prefetch unit for fetching instructions prior to the execution of a previous instruction. Such prefetch units are utilized in computer systems to increase the operating speed of a computer system by ensuring a queue of instructions is available for an instruction decode and instruction execution unit.
In the present invention, after encountering a synchronization instruction, but before execution of the synchronization instruction, the next instruction ("second instruction") is fetched by the prefetch unit. If the instruction is one of a predetermined set of instructions, the synchronization instruction is not executed and a null instruction is executed in its place. If the instruction is not one of the predetermined set of instructions, the synchronization instruction is executed. (In the preferred embodiment, the second instruction may not be prefetched in certain circumstances for a variety of reasons. If the second instruction is not prefetched, the synchronization instruction is executed in the normal execution sequence.)
In the preferred embodiment, many floating point instructions inherently provide for routine synchronization. The predetermined set of instructions comprises the set of such floating point instructions of the instruction set of the microprocessor of the preferred embodiment which inherently provide for routine synchronization; floating point instructions which do not inherently provide for such synchronization are not included in the predetermined set. Further, non-floating point instructions are not included in the predetermined set.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram illustrating a known method of implementing synchronizing control flow instructions.
FIG. 2 is a block diagram of portions of a computer system of the present invention.
FIG. 3 is a flow diagram illustrating a method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A method for processing instructions in a computer system is described. In the following description, numerous specific details are set forth such as specific instructions, etc., in order to provide a thorough understanding of the present invention. It will be obvious, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to unnecessarily obscure the present invention.
OVERVIEW OF THE PRESENT INVENTION
The preferred embodiment of the present invention is proposed for use in the next generation of microprocessor in the Intel 8086 family, commonly referred to as the 80486 tm microprocessor ('486 tm ), manufactured by Intel Corporation of Santa Clara, Calif.
The proposed '486 microprocessor implements the functions of a general purpose microprocessor (such as the functions of the Intel 80386 microprocessor) and the functions of a numeric coprocessor (such as the Intel 80387 numeric coprocessor) in a single component or "chip".
It is desired to ensure that the '486 microprocessor is capable of supporting instruction sequences written for execution on the 80386, including instruction sequences which utilize a numeric coprocessor such as the 80387. Such instruction sequences often include synchronization instructions for synchronizing execution of the 80386 and the 80387.
DESCRIPTION OF 80386 SYNCHRONIZATION
FIG. 1 is a flow diagram illustrating use of such synchronization instructions in an instruction sequence. A typical instruction sequence may include a synchronization instruction which causes the main processor (e.g., the '386) to wait further processing until the numeric coprocessor is available to execute another instruction, block 101 and block 102.
Typically, the synchronization instruction is a WAIT instruction. The synchronization instruction is placed in the instruction sequence to ensure the numeric coprocessor has completed execution of any prior floating point instruction before presenting the next floating point instruction for execution. (As discussed in the Background of the Invention section, the 80387 asserts a BUSY signal while processing an instruction. After completing processing of the instruction, the 80387 deasserts the BUSY pin. The 80386 will suspend execution during the time the BUSY pin is asserted if a WAIT instruction is executed.)
It is worth noting that in many 80386/80387 implementations, programmers do not have to code WAIT instructions in instruction sequences. Many assemblers for the 80386 will automatically encode the WAIT instructions in the instruction sequence.
After the numeric coprocessor indicates it is available for processing of the next instruction (by deasserting the BUSY pin), block 103, the next instruction in the instruction sequence is presented for execution, block 104. (Generally, the next instruction is a floating point instruction; however, in certain cases, it may be a non-floating point instruction.)
Certain instructions in the '386 instruction set include a WAIT state as an integral part of the instruction. In such cases, branch 110, the main processor waits execution of the next instruction in the instruction sequence until the numeric processor signals it has completed processing, block 105 and block 106. Typically, floating point instructions include a WAIT state as an integral part of the instruction where the instruction will affect memory or registers which may also be effected by instructions executing on the general purpose microprocessor.
In other cases, the floating point instruction do not include a WAIT state as an integral part of the instruction. In such cases, the main processor does not wait for the numeric coprocessor to complete processing of the instruction, branch 111. As examples, this second type of instructions include the instructions listed in TABLE I, below:
TABLE I______________________________________Opcode Function______________________________________(1) FSTENV (Store the coprocessor's environment);(2) FSTCW (Store the coprocessor's control word);(3) FSAVE (Save the coprocessor's state);(4) FSTSW (Store the coprocessor's status word);(5) FCLEX (Clear the coprocessor's exception flags);(6) FINIT (Initialize the coprocessor); and(7) FSETPM (Place the coprocessor in protected mode).(8) FENI (Enable interrupt)(9) FDIS (Disable interrupt)______________________________________
(Note that the codes listed in Table I are operation codes ("opcodes") in the '386 instruction set, not mnemonics.)
In the case of either type of instruction, the main processor will begin execution of the next instruction in the instruction sequence at some point in time, block 107.
Further information on the 80386/80387 processors may be found with reference to Chris H. Pappas & William H. Murray, III, 80386 Microprocessor Handbook, Osborne McGraw-Hill, 1988.
GENERAL 80486 ARCHITECTURE OVERVIEW
The proposed 80486 microprocessor comprises a general purpose microprocessor and a numeric coprocessor integrated on a single chip. The proposed '486 microprocessor further comprises instruction prefetch circuitry and instruction decode circuitry.
PREFETCH CIRCUITRY
The prefetch circuitry is described with reference to FIG. 2. A prefetch unit 202 is coupled with a bus 201. This allows the prefetch unit to fetch instructions for processing. The prefetch unit 202 is further coupled with an instruction decode unit 203. The instruction decode unit 203 is provided with instructions for decoding by the prefetch unit 202. Finally, the instruction decode unit 203 is coupled with an execution unit 204 for providing microcoded instructions for execution.
The prefetch unit 202 requests an instruction and stores the instruction in a prefetch queue until the instruction decode 203 is available to process the instruction and translate the instruction into microcode. An instruction queue in the instruction decode unit 203 holds the microcoded instructions until they are executed by an execution unit 204.
Requirement for Synchronization Instructions in the Preferred Embodiment
As discussed above, in the prior art it is known to include synchronization instructions in instruction sequences to ensure proper execution. The present invention teaches that in certain cases, synchronization instructions are not necessary for ensuring the proper execution of the instruction sequence.
Specifically, the present invention teaches that synchronization instructions may not be required depending on the instruction immediately following a synchronization instruction. If the instruction immediately following the synchronization instruction includes a WAIT state as an integral part of the instruction, it has been observed that coding of a WAIT instruction previous to such an instruction is not necessary.
As one objective the present invention, a computer system is to be developed which ensures compatability with instruction sequences written for systems such as the '386. As a second objective, it is desired to increase the performance of the computer system of the present invention by effectively removing certain synchronization instructions from such instruction sequences.
It is worth noting that, in the system of the preferred embodiment, a WAIT instruction requires a minimum of 3 clock cycles to complete. As will be detailed below, the system of the present invention effectively removes from execution certain WAIT instructions and replaces the WAIT instruction with a null operation. In the preferred embodiment, the null operation requires 1 clock cycle for execution.
METHOD OF THE PREFERRED EMBODIMENT
A method utilized by the preferred embodiment to improve execution time of an instruction sequence by removing selected synchronization instructions is described with reference to the flow diagram of FIG. 3.
In an instruction sequence, a synchronization instruction may be encountered, block 301. As stated previously, instruction sequences commonly utilize the WAIT instruction of the instruction set for the 8086 family of microprocessors as a synchronization instruction .
As described previously, the WAIT instruction is used to cause the general purpose processor portion of the computer system to wait, or suspend, execution of instructions until the numeric processor portion of the computer system has finished a task.
The system of the present invention comprises means for allowing the next instruction in the instruction sequence to be fetched and examined prior to executing the next instruction in the instruction sequence, block 202. In the preferred embodiment, the prefetch unit waits until the bus is available and fetches the next instruction and stores it in a prefetch queue. In certain cases, such as when the bus is servicing higher priority requests, prefetching does not occur.
Assuming the prefetch was successful, block 103, the present invention teaches determining whether the instruction fetched is one of a set of instructions for which the previous synchronization is not necessary. It has been determined that synchronization instructions are not necessary in instruction sequences before certain so-called "safe" instructions.
In the preferred embodiment, these "safe" instructions include instructions to be executed by the numeric processor which include a WAIT state as an integral part of the instruction. (In general, in the instruction set of the processor of the preferred embodiment, these instruction are the floating point instructions, such as F2XM1, FABS, FADD/FADDP, FBLD, FBSTP, etc.).
The predetermined set of "safe" instructions in the preferred embodiment does not include certain floating point instructions which do not have synchronization built into the instruction. Examples of these instructions are listed with reference to TABLE I, above. Further, the predetermined set of safe instructions of the preferred embodiment does not include any instructions to be executed by the general purpose processor (e.g., non-floating point instructions such as LOOP, LSL, MOV, MUL, etc.).
By way of example, the instruction sequence detailed in TABLE II may have been written for execution on a computer system utilizing an 80386:
TABLE II______________________________________Instruction # Instruction______________________________________(1) WAIT(2) FINIT(3) WAIT(4) FILD Word Ptr (0006)(5) WAIT(6) FLDPI(7) WAIT(8) FDIV ST,ST(1)______________________________________
Synchronization instructions numbered 3, 5 and 7 in TABLE II are not necessary for proper execution of the instruction sequence on a computer system embodying the '486 processor. Therefore, the method of the present invention replaces the synchronization instructions (WAIT instructions) with a null instruction, block 305. The null instruction requires one clock cycle for execution as opposed to a minimum of three clock cycles for the WAIT instruction.
Synchronization instruction numbered 1 in TABLE II is required by the computer system of the present invention and, therefore, is not replaced by a null instruction. This synchronization instruction is required because the FINIT instruction does not include a WAIT state as an integral part of the instruction.
In general, in the system of the present invention, synchronization instructions preceding floating point instructions which provide routine synchronization are replaced with a null instruction. The null instruction does not perform any operation; rather it only affects the (E)IP register (instruction pointer register).
In other cases, such as synchronization instructions preceding non-floating point instructions and synchronization instruction preceding floating point instructions not providing routine synchronization, the synchronization instruction are executed in the normal course of the instruction sequence, block 306.
Thus, a method for avoiding time penalties associated with synchronization instructions is described. Although the present invention has been described with specific reference to a number of details of the preferred embodiment, it will be obvious that a number of modifications and variations may be employed without departure from the scope and spirit of the present invention. Accordingly, all such variations and modifications are included within the intended scope of the invention as defined by the following claims. | A method for conditional speed-up of execution of an instruction sequence having synchronization instructions. The method has particular application in a computer system in which compatability with instruction sequences written for the Intel 80386 or earlier processors is desirable. The method discloses replacement of certain WAIT state instruction in an instruction sequence with a null instruction in cases where the WAIT state instruction is followed by a floating point instruction including as an integral part of the instruction a WAIT state. | 6 |
BACKGROUND
[0001] 1. Technical Field
[0002] Embodiments of the present disclosure relate to user interfaces, and more particularly to an electronic device and method for surveillance control thereof.
[0003] 2. Description of Related Art
[0004] Vendors of surveillance devices rarely adopt unified surveillance system software. Incompatibilities among surveillance systems cause different surveillance devices difficulties in sharing and communication information with one another. In addition, controls of surveillance systems are usually rigid and not user friendly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram of one embodiment of an electronic device providing surveillance control.
[0006] FIG. 2 is a flowchart illustrating one embodiment of a method for surveillance control.
[0007] FIG. 3 is a flowchart illustrating one embodiment of step S 1 in FIG. 2 .
[0008] FIG. 4 is a flowchart illustrating one embodiment of step S 2 in FIG. 2 .
[0009] FIG. 5 is a flowchart illustrating one embodiment of step S 3 of FIG. 2 .
[0010] FIG. 6 is a flowchart illustrating one embodiment of a method for changing the position of an Icon control component.
[0011] FIG. 7 is a flowchart illustrating one embodiment of step S 316 of FIG. 5 .
[0012] FIG. 8 is a flowchart illustrating one embodiment of a method for displaying the Icon control component.
[0013] FIG. 9 is a flowchart illustrating one embodiment of step S 4 in FIG. 2 .
DETAILED DESCRIPTION
[0014] The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
[0015] In general, the word “module” as used herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, for example, Java, C, or assembly. One or more software instructions in the module may be integrated in firmware, such as an EPROM. It will be appreciated that module may comprise connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The units described herein may be implemented as software and/or hardware unit and may be stored in any type of computer-readable medium or other computer storage device.
[0016] FIG. 1 is a block diagram of an electronic device 10 comprising a display device 30 and a surveillance control system 20 . The electronic device 10 is electronically connected with at least one digital video recorder 40 and an input device 50 . The digital video recorder 40 is connected with the electronic device 10 via a communication network. The communication network can be a local area network, a personal area network, WIFI, or the Internet, for example. The input device 50 may be a keyboard and a mouse connected to the electronic device 10 , for example, to conduct data registration for the electronic device 10 . The electronic device 10 further comprises a memory system 102 to store a database 22 which contains names and locations of monitor points. In the embodiment, the monitor points represents the at least one digital video recorder 40 on an electronic map. One monitor point corresponds to one digital video recorder 40 . Depending on the embodiment, the electronic device 10 can be a personal computer, or a notebook, for example.
[0017] The system 20 includes a display module 200 , a set-up module 202 , a generation module 204 , a storage module 206 , and a surveillance module 208 . One or more computerized codes of the modules 200 - 208 are stored in the memory system 102 and executed by one or more processors 101 of the electronic device 10 .
[0018] In the embodiment, the display module 200 is operable to display the monitor points on the display device 30 . The monitor points are maintained with a tree data-structure according to a hierarchy of geographic locations of the at least one digital video recorder 40 . For example, Shenzhen/LongHua/B3/3 rd floor means a monitor point at the 3 rd floor of building B3, in Long Hua district, in Shenzhen, wherein the 3 rd floor is a leaf node of the tree data-structure. The monitor points are stored in the memory system 102 using the database 22 .
[0019] In the embodiment, the set-up module 202 is operable to set up the electronic map for the monitor points and to save the electronic map in the database 22 . The display module 200 displays the electronic map on the device 30 . In the embodiment, the monitor point is a leaf node of the tree data-structure.
[0020] In the embodiment, the generation module 204 generates an Icon control component for a selected monitor point in the electronic map, in response to a drag and drop operation on the selected monitor point. In addition, the generation module 204 changes the position of the generated Icon control component on the electronic map using the drag and drop operation. The Icon control component is an assembly of certain icon control component components of MICROSOFT .NET Framework encapsulated by the generation module 204 .
[0021] In the embodiment, the storage module 206 is operable to store an identifier (ID) of the Icon control component in the database 22 stored in the memory system 102 , in response to a confirmation of the position of the icon control component on the electronic map from the user. In the embodiment, the confirmation can be a click on a “save” button on the electronic map. The display module 200 displays the Icon control component stored previously on the display device 30 .
[0022] In the embodiment, the surveillance module 208 is operable to connect to the digital video recorder 40 via the communication network, in response to a click event of the input device 50 . The click event is associated with the Icon control component by the generation module 204 upon generation.
[0023] FIG. 2 is a flowchart of one embodiment of a method for surveillance control of the electronic device 10 . Depending on the embodiments, additional blocks may be added, others removed, and the ordering of the blocks may be changed.
[0024] In block S 1 , the display module 200 displays the monitor point tree on the display device 30 . In block S 2 , the set-up module 202 sets up the electronic map for the monitor point tree and saves the electronic map in the database 22 stored in the memory system 102 of the electronic device 10 . The display module 200 displays the electronic map on the device 30 . In block S 3 , the generation module 204 generates the Icon control component for the selected node of the monitor point tree, in the electronic map, in response to a drag and drop operation of the input device 50 on the selected node. In addition, the generation module 204 can change the position of the generated Icon control component on the electronic map using the drag and drop operation. In the embodiment, the display module 200 displays the Icon control component stored previously on the display device 30 . In block S 4 , the surveillance module 208 connects to the video feed of the digital video recorder 40 , in response to a click event of the input device 50 . The surveillance module 208 shows a video feed page. The display module 200 plays the video feed of the digital video recorder on the video feed page.
[0025] FIG. 3 is a flowchart illustrating one embodiment of step S 1 in FIG. 2 . In block 10 , the display module 200 reads the information of each monitor point from the database 22 stored in the memory system 102 of the electronic device 10 . In the embodiment, the information includes names and locations of the monitor points. In block 11 , the display module 200 binds each monitor point to the node of the tree data-structure according to the hierarchy of geographic location of the digital video recorder 50 and displays the nodes as the monitor point tree on the display device 30 . In the embodiment, the tree data-structure is implemented with UltraWebTree, a component of MICROSOFT .NET Framework. In block 12 , a user selects a node from the tree structure using the input device 50 . In block 13 , the display module 200 verifies if the selected node is a leaf node. If the selected node is a leaf node, the process goes to block S 14 . If the selected node is not a leaf node, the process goes back to block S 12 . In block S 14 , the display module reads the corresponding name of the selected node from the database 22 and displays the corresponding name on the display device 30 .
[0026] FIG. 4 is a flowchart illustrating one embodiment of step S 2 in FIG. 2 . In block 20 , the set-up module 202 shows a set-up page. In block S 21 , the set-up module 202 selects an image file from the memory system 102 using a FileUpload component of MICROSOFT .NET Framework, in response to a click on a “set up electronic map” button on the set-up page. In the embodiment, the image file is the electronic map file. In block S 22 , the set-up module 202 verifies if the format of selected file is compatible using a RegularExpressionValidator component of MICROSOFT .NET Framework. If the format is compatible, the process goes to block S 24 . Otherwise, the process goes to block S 23 . In the embodiment, the compatible image file formats are GIF, PNG, JPG, and BMP. In block S 23 , the set-up module 202 informs the user that the selected file is not compatible, and the process goes back to block S 21 . In block S 24 , the set-up module 202 scales the selected file to fit the display device 30 of the electronic device 10 , 70% smaller for example, using an AlphaImageLoader component of MICROSOFT .NET Framework. In block S 25 , the set-up module 202 converts the selected file into a binary string, using a predetermined conversion function In block S 26 , the set-up module 202 stores the binary string in the database 22 , using a predetermined save function, in response to a click on a “save map” button on the set-up page. In block S 27 , the display module 200 refreshes the parent page, using a refresh function to display the saved file.
[0027] FIG. 5 is a flowchart illustrating one embodiment of step S 3 of FIG. 2 . In block S 310 , the generation module 204 verifies if the electronic map has been set up. If the electronic map has been set up, the process goes to S 311 . Otherwise, the process goes to S 312 . In block S 312 , the generation module 204 reminds the user to set up the electronic map before proceeding and the process ends. In block S 311 , the user drags a selected node of the monitor point tree to the electronic map and drops the selected node on the electronic map, using the input device 50 . The generation module 204 stores information of the Icon control component in the memory system 102 . In the embodiment, the information includes an ID and position of the Icon control component, wherein the ID consists of the string “pic” concatenated with the name of the selected node and the position is where the user drops the node. In block S 313 , the generation module 204 creates an Icon control component in response to the drop operation of the input device 50 , using JAVA script technology. If the Icon control component has already been generated, the generation module 204 informs the user that the Icon control component has already been generated. In block S 314 , the generation module 204 assigns an icon image to the created Icon control component. In block S 314 , the generation module 204 associates the assigned Icon control component with a click event using MICROSOFT .NET Framework. In the block S 316 , the display module 200 shows the Icon control component as the assigned icon image on the electronic map on the position thereof.
[0028] FIG. 6 is a flowchart illustrating one embodiment of a method for changing the position of the Icon control component on the electronic map. In block S 320 , the user selects a generated Icon control component from the electronic map. In block S 321 , the generation module 204 saves the ID and position of the selected Icon. In block S 322 , the generation module 204 tracks the present position of Icon control component in response to the drag operation. In block S 323 , the generation module 204 moves the Icon control component to the present position using a transpose function call, in response to the drop operation. In block S 324 , the generation module 204 saves the new position to the position entry of the generated Icon control component in the database 22 stored in the memory system 102 of the electronic device 10 , in response to the drop operation.
[0029] FIG. 7 is a flowchart illustrating one embodiment of step S 316 of FIG. 5 . In block S 410 , the storage module 206 retrieves the ID and position of the Icon control component, in response to the click on the “save” button on the set-up page. In block S 411 , the storage module 206 resolves the name and location of the monitor point corresponding to the Icon control component using Ajax technology. In block S 412 , the storage module 206 stores the ID and position of the Icon control component along with the name and location of the monitor point in the database 22 stored in the memory system 102 of the electronic device 10 .
[0030] FIG. 8 is a flowchart illustrating one embodiment of a method for displaying the Icon control component. In block S 420 , the user selects a leaf node from the monitor point tree. In block 421 , the display module 200 reads the binary string according to the name of the selected leaf node from the database 22 . In block S 422 , the display module 200 converts the binary string to the image file and uses the image file as a background image. In block S 423 , the display module 200 resolves the names and locations of all the nodes of the monitor point tree. In block S 424 , the display module 200 retrieves the IDs and positions of the Icon control components according to the monitor point tree. In block S 425 , all the Icon control components are displayed on the electronic map.
[0031] FIG. 9 is a flowchart illustrating one embodiment of step S 4 in FIG. 2 . In block S 50 , the surveillance module 208 shows a video feed page, in response to a click on the generated Icon control component on the electronic map. In block S 51 , the display module 200 resolves the name and location of the monitor point corresponding to the clicked Icon control component and sends the name of the monitor point to the video feed page. In block S 52 , the surveillance module 208 connects and logs in the digital video recorder 40 and the display module 200 plays the video feed of the digital video recorder 40 on the video feed page, using Software Development Kit (SDK) of the digital video recorder 40 .
[0032] Although certain inventive embodiments of the present disclosure have been specifically described, the present disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the present disclosure without departing from the scope and spirit of the present disclosure. | An electronic device connected with at least one digital video camera dynamically monitors an area where the digital video camera covers. The electronic device displays a monitor point tree, where each node corresponds to a digital video camera. The electronic device can dynamically create an icon control component of a selected digital video camera on an electronic map by dragging and dropping the node corresponding to the one selected on a electronic map. The electronic device can play a video feed of the digital video camera by clicking on the created icon control component. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to metal roofs. More particularly, the invention relates to a metal roof system for use over an existing low slope modified bitumen, single ply rubber or built up roof.
[0003] 2. Description of the Related Art
[0004] Many structures utilize low slope modified bitumen, single ply rubber or built up roofs to protect the interior of the structure from exposure to the elements, including sun, rain, snow, and the like. Modified bitumen, single ply rubber or built up roofs are utilized on metal, brick, wood, and other structures. Generally, the structure is built with interior columns that support a series of rafters or beams attached at the top of the columns. The roof rafters or beams are typically attached in a low-sloped manner with a ridge at the top to provide downward drainage. Spanning the rafters or beams is a wooden deck or a light gauge metal deck which is in turn covered with insulation and modified bitumen, single ply rubber or built up roofing. The decking generally runs perpendicular to the rafters or beams and is configured to be interconnected providing structural support for the overlying low slope modified bitumen, single ply rubber or built up roof. The low sloped roof usually consists of a layer of insulation board covered by either a multi-layer built up roof, a single ply rubber membrane or a modified bitumen membrane and are secured to a roof deck structure by nails, screws, clips, or other type fasteners. These low slope roofs find applications in many building constructions, such as commercial and industrial buildings.
[0005] Over time, due to wear and other factors, the existing low slope modified bitumen, single ply rubber or built up roof is either removed and replaced with another modified bitumen, single ply rubber or built up roof or re-roofed by placing a new metal roof on top of the existing low slope modified bitumen, single ply rubber or built up roof. Re-roofing of such roofs with metal is difficult since the reroofing operation typically requires additional support structure to add slope to the existing low sloped modified bitumen, single ply rubber or built up roof or insulation layers or possibly a wood layer to accept the new roof. The addition of a typical support structure makes this system difficult and expensive to apply effectively. Additionally, reroofing of low sloped roofs with metal is typically hard to effectively weatherproof due to the slope of the roof which results in a less then optimum downward drainage. Furthermore, the metal panels in the new roof are subject to considerable movement together with the building due to the expansion and contraction of the panels by heat, cold, wind, etc. making it extremely difficult to provide a satisfactory weatherproof seal along the seams and at the fastener locations since over time the panels and their seams tend to become loose and create a potential leak path.
[0006] A need therefore exists for a reliable and a weatherproof metal roof system for use to re-roof an existing low slope modified bitumen, single ply rubber or built up roof without adding slope.
SUMMARY OF THE INVENTION
[0007] The present invention generally relates to a metal roof system. In one aspect, a method of placing a roof system over an existing low slope modified bitumen, single ply rubber or built up roof is provided. The method includes measuring a slope plane of the existing low slope modified bitumen, single ply rubber or built up roof to determine the location of irregularity points. Thereafter, at least one shim member is placed proximate each low irregularity point and at other predetermined locations. Next, an air space is formed between the existing low sloped roof and the roof system and then the roof system is operatively attached to the existing low sloped roof.
[0008] In another aspect, a method of placing a roof system over an existing low sloped roof is provided. The method includes placing at least one shim member proximate each irregularity point on the existing low sloped roof and at other predetermined locations. The method further includes reducing the heat transfer from the roof system to a building or structure below by forming an air space between the roof system and the existing low sloped roof. Further, the method includes operatively attaching the roof system to the existing low sloped roof.
[0009] In yet another aspect, a method of placing a roof system over an existing low sloped roof is provided. The method includes measuring a slope plane of the existing low sloped roof to determine the location of irregularity points and then placing at least one shim member proximate each low irregularity point and at other predetermined locations. The method also includes directing the thermal movement of the roof system by employing a plurality of fixed and floating clips at predetermined locations between the roof system and the existing low sloped roof and then operatively attaching the roof system to the existing low sloped roof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] 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.
[0011] FIG. 1 is a view illustrating a sidewall arrangement of a roof system in accordance with the present invention.
[0012] FIG. 2 is a view illustrating a headwall arrangement and a curb arrangement of the roof system in accordance with the present invention.
[0013] FIG. 3 is a view illustrating the headwall arrangement.
[0014] FIG. 4 is a view illustrating the curb arrangement.
DETAILED DESCRIPTION
[0015] The present invention generally relates to a metal roof system for use on an existing low sloped modified bitumen, single ply rubber or built up roof. The metal roof system is comprised of clips, shims, roof panels, and other components. Prior to installing the metal roof system, the existing low sloped modified bitumen, single ply rubber or built up roof must be examined to determine if it is suitable for a retrofit. For example, the existing roof decking is examined to determine if the decking is capable of holding fasteners. Additionally, the structure of the existing roof is examined to determine if the structure is capable of holding additional weight. After the existing low sloped roof has been completely examined and has met certain criteria, the metal roof system of the present invention may be employed in accordance with the method described herein. To better understand the novelty of the apparatus of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings.
[0016] FIG. 1 is a view illustrating a sidewall arrangement 150 of a roof system 100 in accordance with the present invention. Generally, the sidewall arrangement 150 is a portion of the roof system 100 adjacent a wall 155 on an existing roof 10 . The sidewall arrangement is constructed of various components to ensure that there is a weatherproof relationship between the wall 155 and the roof system 100 .
[0017] The sidewall arrangement 150 includes a plurality of shims 165 or bearing plates positioned at predetermined locations along on top of the existing roof 10 . Prior to positioning the shims 165 , the slope of the existing roof 10 is measured by a level device (not shown). The level device is used to determine the amount of shimming that will be required to make the roof system 100 straight and true. Next, the shims 165 are used to fill low spots or irregularities and other predetermined locations on the existing roof 10 to ensure that the roof system 100 is substantially without dips which typically hold water. It should be noted that a plurality of shims may be employed at any one location without departing from principles of the present invention. In one embodiment, the shims 165 are constructed from a plastic or composite material. Additionally, the shims 165 or bearing plates are used to increase the contact surface area between a clip 120 and the existing roof 10 . Furthermore, the shims 165 are used to create an airspace 135 between the existing roof 10 and the roof system 100 .
[0018] The airspace 135 is generally used as insulation to reduce the amount of heat transferred from the roof system 100 through the existing roof 10 into the building or structure below (not shown). In reducing the amount of heat transferred into the building or structure below the roof system 100 , the energy required to heat or cool the building or structure is subsequently reduced. In one embodiment, a radiant barrier may be disposed in the airspace 135 to further reduce the amount of heat transfer between the roof system 100 and the building or structure below. It should be understood, however, that any form of insulation may be employed in the airspace 135 without departing from principles of the present invention
[0019] The sidewall arrangement 150 further includes a plurality of clips 120 positioned on top of the shims 165 . The clips 120 are secured to the existing roof 10 by a plurality of fasteners 130 . The primary function of the clips 120 is to secure the roof system 100 to the existing roof 10 . More particularly, the clips 120 provide a means of supporting a roof panel 125 and holding new roof panels together. The clips 120 may be a fixed clip which is secured at one location or a floating clip which is capable of moving a predetermined distance. The floating clip allows the panel 125 to move as the panel 125 expands or contracts due to heat, cold, etc. Therefore, the placement of the fixed and floating clips at predetermined locations on the existing roof controls the direct thermal movement of the roof system 100 . In one embodiment, the fixed clips will be used in the middle area or top area of the roof system 100 and all other clips will be floating clips installed in such a manner where a sliding mechanism is in the center of the clip allowing the panel to move in either direction. Another function of the clips 120 adjacent the wall 155 is to support a sidewall cleat 110 .
[0020] As illustrated in FIG. 1 , the sidewall cleat 110 is attached both to a seam of the panel 125 and to the clips 120 by a fastening member 170 . Typically, a tape seal 140 is disposed between the panel 125 and the sidewall cleat 110 to create a watertight sealing relationship therebetween. The tape seal 140 is generally an elastomeric material that is capable of forming a fluid seal between two members. The sidewall cleat 110 or extension member is used to raise the perimeter of the roof system 100 along the wall 155 to ensure a weatherproof arrangement between the roof system 100 and the building or structure below. The sidewall arrangement 150 also includes a sidewall trim 105 that extends downwardly over the sidewall cleat 110 . The sidewall trim 105 is used to direct particles, such as water, toward the roof panel 125 . It should be noted that the sidewall trim 105 is not operatively attached to the roof panel 125 , thereby allowing the roof panel 125 to expand or contract without affecting the sidewall trim 105 . Additionally, the panel 125 is sloped in the direction indicated by arrow 115 to facilitate the downward drainage of the particles, such as water.
[0021] FIG. 2 is a view illustrating a headwall arrangement 200 and a curb arrangement 250 of the roof system 100 in accordance with the present invention. The headwall arrangement 200 is generally used to create a weatherproof relationship between a head wall 245 and the roof system 100 , as illustrated in FIGS. 2 and 3 . The curb arrangement 250 is generally used to create a weatherproof relationship between a penetration, such as an AC unit or a sky light (not shown), and the roof system 100 , as illustrated in FIGS. 2 and 4 . For convenience, the components in the sidewall arrangement 150 that are similar to the components in the headwall arrangement 200 and the curb arrangement 250 will be labeled with the same number indicator.
[0022] As illustrated in FIG. 3 , the headwall arrangement 200 includes a plurality of shim members 165 disposed on top of the existing roof 10 . Typically, a roof panel 225 that adjoins the head wall 245 will have extra shims 165 to support the top of the panel. Thereafter, a strip member 215 is placed on top of the shim members 165 adjacent the headwall 245 . In one embodiment, the strip member 215 is a 6″ wide, 16 gauge piece of sheet metal. A lower zee 210 is positioned inside the panel 225 and operatively attached to the strip member 215 by a plurality of fasteners 170 . The tape seal 140 is disposed between the strip member 215 and the panel 225 to create a fluid tight relationship therebetween. It should be noted that lower zee 210 and the strip member 215 are not attached to the existing roof 10 , thereby allowing the panel 225 to expand or contract without affecting the headwall arrangement 200 . Additionally, panel 225 is sloped in the direction indicated by arrow 230 to facilitate the downward drainage of the particles, such as water.
[0023] The roof panel 225 and other main roof panels are typically continuous along their entire length from the ridge or headwall to the eave with no end laps. In one embodiment, the roof panel 225 and other roof panels (not shown) in the roof system 100 have different panel widths to ensure that the last panel seam lands at a predetermined distance from a penetration or a wall. Additionally, in another embodiment, the roof panel 225 and other panels in the roof system 100 have a vertical seam arrangement, thereby allowing versatility and more complex roof geometry.
[0024] As shown, an upper zee 205 is attached to an upper end of the lower zee 210 by a plurality of fasteners 170 . Additionally, the tape seal 140 is disposed between the upper and lower zees 205 , 210 to create a fluid tight relationship therebetween. The upper zee 205 is used to raise the perimeter of the roof system 100 along the headwall 245 or ridge to ensure a weatherproof arrangement between the roof system 100 and the building or structure below. The headwall arrangement 200 also includes a headwall trim 220 operatively attached to the upper zee 205 by fasteners 170 . The headwall trim 220 is used to direct particles, such as water, toward the roof panel 225 . Typically, a seal member (not shown) is employed between the headwall trim 220 and the headwall 245 to create a sealing relationship therebetween.
[0025] Referring back to FIG. 2 , the curb arrangement 250 is positioned adjacent the headwall arrangement 200 . It should be understood, however, that the curb arrangement 250 may be positioned at any location on the roof system 100 , without departing from principles of the present invention. As illustrated, a panel 255 on the curb arrangement 250 is raised in relation to the panel 225 and run substantially perpendicular to panel 225 , thereby allowing the panel 255 to direct particles, such as water, into the panel 225 . Additionally, panel 255 is sloped in the direction indicated by arrow 260 to facilitate the downward drainage of the particles.
[0026] As illustrated in FIG. 4 , shim 165 is placed on top of the existing roof 10 . A clip 280 is placed on top of the shim 165 and secured to the existing roof 10 by fastener 130 . Disposed on the upper end of the panel seam is a side cleat 275 . The side cleat 275 is used to raise the perimeter of the roof system 100 along curb arrangement 250 to ensure a weatherproof arrangement between the roof system 100 and the building or structure below. Additionally, the side cleat 275 is adjacent a structural zee member 270 disposed on top of the shim 165 . A transverse panel trim 265 is disposed adjacent the zee member 270 . The transverse panel 255 is secured to the transverse panel trim 265 by fasteners 170 . The transverse panel trim 265 and the zee member 270 are constructed and arranged to allow the panel 225 to expand or contract without affecting the curb arrangement 250 . Additionally, the tape seal 140 is typically disposed between the members of the curb arrangement 250 to ensure a fluid tight relationship therebetween.
[0027] 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. | The present invention generally relates to metal roofs. In one aspect, a method of placing a roof system over an existing low sloped roof is provided. The method includes measuring a slope of the existing low sloped roof to determine the location of irregularity points. Thereafter, at least one shim member is placed proximate each irregularity point and at other predetermined locations. Next, an airspace is formed between the existing low sloped roof and the roof system and then the roof system is operatively attached to the existing low sloped roof. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2014-076769 filed in Japan on Apr. 3, 2014, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates to a method for preparing silazane compounds which are useful as synthesis intermediates for paint additives, polymer modifiers, pharmaceuticals, and agricultural chemicals.
BACKGROUND ART
[0003] Silazane compounds are useful as intermediates for the synthesis of paint additives, polymer modifiers, pharmaceuticals, and agricultural chemicals.
[0004] As is well known in the art, silazane compounds are prepared by reaction of a halosilane compound with an amino-containing compound. In this reaction, not only the target silazane compound, but also a hydrogen halide by-product forms. The hydrogen halide reacts with the amino-containing compound to form a hydrogen halide salt of the amino-containing compound in stoichiometric amount. The resulting hydrogen halide salt of the amino-containing compound is normally solid, does not dissolve in the reaction system, and precipitates out during the reaction. The precipitates turn the reaction solution into a slurry, interfering with stirring. Generally, a solvent is added to continue stirring during the reaction. For example, U.S. Pat. No. 2,429,883 discloses a method for preparing silazane compounds using diethylether or benzene as a solvent.
CITATION LIST
[0005] Patent Document 1: U.S. Pat. No. 2,429,883
DISCLOSURE OF INVENTION
[0006] However, a large amount of solvent is required to continue stirring. The solvent must be distilled off when the target silazane compound is isolated by distillation. These procedures are cumbersome. Accordingly, there is a need for a more efficient method for preparing silazane compounds.
[0007] An object of the invention is to provide a method for efficiently preparing silazane compounds.
[0008] The inventors have found that a silazane compound is efficiently prepared by reaction of a halosilane compound with an amino-containing compound when a silazane compound which is the same as the target product is used as a solvent. When the same silazane compound as the target product is used as a solvent, the resulting slurry which contains a hydrogen halide salt of the amino-containing compound is improved in fluidity. The amount of the solvent used is reduced. Since the solvent is the silazane compound, the step of fractional distillation of the solvent is unnecessary.
[0009] According to the invention, there is provided a method for preparing a silazane compound, comprising the step of reacting a halosilane compound having the general formula (1):
[0000] R 1 n SiX (4-n) (1)
[0000] wherein R 1 is each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, X is a halogen atom, n is an integer of 0 to 3, and R 1 groups bond together to form a C 2 -C 20 ring with the silicon atom to which they are attached when n is 2 or 3, with an amino-containing compound having the general formula (2):
[0000] R 2 R 3 NH (2)
[0000] wherein R 2 and R 3 are independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, or the general formula (3):
[0000]
[0000] wherein R 4 is a divalent organic group of 1 to 20 carbon atoms which may contain a heteroatom, in a solvent which is the same silazane compound as the target product.
[0010] In a preferred embodiment, the silazane compound has the general formula (4), (5), (6) or (7).
[0000] R 1 n Si(NR 2 R 3 ) (4-n) (4)
[0000] Herein R 1 , R 2 , R 3 and n are as defined above.
[0000]
[0000] Herein R 1 , R 4 and n are as defined above.
[0000]
[0000] Herein R 1 and R 3 are as defined above, and n is 3.
[0000]
[0000] Herein R 1 and R 3 are as defined above, a is an integer of 2 to 20, and n is 2.
[0011] In a preferred embodiment, R 2 and R 3 in formula (2) are independently a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms.
[0012] A hydrogen halide salt of the amino-containing compound forms during the reaction. In a preferred embodiment, an alkaline aqueous solution is added to the reaction solution to dissolve the hydrogen halide salt of the amino-containing compound in the alkaline aqueous solution, thereby separating the amino-containing compound from an organic layer containing the silazane compound.
Advantageous Effects of Invention
[0013] According to the invention, silazane compounds can be efficiently prepared, which are useful as synthesis intermediates for paint additives, polymer modifiers, pharmaceuticals and agricultural chemicals.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] One embodiment of the invention is a method for preparing a silazane compound by reaction of a halosilane compound having the general formula (1):
[0000] R 1 n SiX (4-n) (1)
[0000] wherein R 1 is each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, X is a halogen atom, n is an integer of 0 to 3, and R 1 groups bond together to form a C 2 -C 20 ring with the silicon atom to which they are attached when n is 2 or 3, with an amino-containing compound having the general formula (2) or (3):
[0000] R 2 R 3 NH (2)
[0000] wherein R 2 and R 3 are independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms,
[0000]
[0000] wherein R 4 is a divalent organic group of 1 to 20 carbon atoms which may contain a heteroatom. In the reaction, a silazane compound which is the same as the target product is used as a solvent.
[0015] In formulae (1) and (2), R 1 to R 3 are each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, which includes straight, branched or cyclic alkyl, alkenyl, aryl, and aralkyl groups. Examples include straight alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and eicosyl, branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, thexyl and 2-ethylhexyl, cyclic alkyl groups such as cyclopentyl and cyclohexyl, alkenyl groups such as vinyl, allyl and propenyl, aryl groups such as phenyl and tolyl, and aralkyl groups such as benzyl, with methyl, ethyl, isopropyl, sec-butyl and tert-butyl being preferred. The substituted forms of the foregoing groups in which some or all hydrogen atoms are substituted are also acceptable. Suitable substituents on the foregoing groups include alkoxy groups such as methoxy, ethoxy and (iso)propoxy, halogen atoms such as fluorine, chlorine, bromine and iodine, cyano groups, amino groups, acyl groups of 2 to 10 carbon atoms, trichlorosilyl groups, and trialkylsilyl, dialkylmonochlorosilyl, monoalkyldichlorosilyl, trialkoxysilyl, dialkylmonoalkoxysilyl and monoalkyldialkoxysilyl groups wherein each alkyl or alkoxy moiety has 1 to 5 carbon atoms.
[0016] In formula (3), R 4 is a divalent organic group of 1 to 20 carbon atoms which may contain a heteroatom, examples of which include alkylene groups such as methylene, ethylene, methylethylene, propylene, methylpropylene, tetramethylene, hexamethylene, octamethylene, decamethylene and isobutylene, arylene groups such as phenylene, aralkylene groups such as methylenephenylene and methylenephenylenemethylene, and alkylene groups containing a heteroatom (e.g., oxygen and nitrogen), such as 3-oxapentylene, 3-azapentylene and 3-methy-3-azapentylene.
[0017] In formula (1), the halogen atom is selected from fluorine, chlorine, bromine, and iodine.
[0018] Examples of the halosilane compound of formula (1) include dimethylchlorosilane, trimethylchlorosilane, diethylchlorosilane, ethyldimethylchlorosilane, diethylmethylchlorosilane, triethylchlorosilane, vinyldimethylchlorosilane, tripropylchlorosilane, triisopropylchlorosilane, tributylchlorosilane, tert-butyldimethylchlorosilane, di-tert-butylmethylchlorosilane, tri-tert-butylchlorosilane, triisobutylchlorosilane, tri-sec-butylchlorosilane, hexyldimethylchlorosilane, thexyldimethylchlorosilane, octyldimethylchlorosilane, decyldimethylchlorosilane, octadecyldimethylchlorosilane, cyclopentyldimethylchlorosilane, cyclohexyldimethylchlorosilane, tricyclopentylchlorosilane, tricyclohexylchlorosilane, dimethylphenylchlorosilane, methyldiphenylchlorosilane, triphenylchlorosilane, tert-butyldiphenylchlorosilane, di-tert-butylphenylchlorosilane, styryldimethylchlorosilane, 2-cyanoethyldimethylchlorosilane, acetoxypropyldimethylchlorosilane, 3-acryloxypropyldimethylchlorosilane, 3-methacryloxypropyldimethylchlorosilane, chloromethyldimethylchlorosilane, 3-chloropropyldimethylchlorosilane, 3,3,3-trifluoropropyldimethylchlorosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexyldimethylchlorosilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyldimethylchlorosilane, dichlorosilane, methyldichlorosilane, dimethyldichlorosilane, ethyldichlorosilane, diethyldichlorosilane, vinylmethyldichiorosilane, divinyldichlorosilane, propylmethyldichiorosilane, dibutyldichlorosilane, tert-butylmethyldichlorosilane, di-tert-butyldichlorosilane, diisobutyldichlorosilane, di-sec-butyldichlorosilane, hexylmethyldichlorosilane, thexylmethyldichiorosilane, octylmethyldichlorosilane, decylmethyldichlorosilane, octadecylmethyldichiorosilane, cyclopentylmethyldichlorosilane, cyclohexylmethyldichlorosilane, dicyclopentyldichlorosilane, dicyclohexyldichlorosilane, methylphenyldichlorosilane, diphenyldichlorosilane, tert-butylphenyldichlorosilane, styrylmethyldichlorosilane, 2-cyanoethylmethyldichlorosilane, acetoxypropylmethyldichlorosilane, 3-acryloxypropylmethyldichlorosilane, 3-methacryloxypropylmethyldichlorosilane, chloromethylmethyldichlorosilane, 3-chloropropylmethyldichlorosilane, 3,3,3-trifluoropropylmethyldichlorosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexylmethyldichiorosilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecylmethyldichlorosilane, trichlorosilane, methyltrichlorosilane, ethyltrichlorosilane, vinyltrichlorosilane, propyltrichlorosilane, isopropyltrichlorosilane, butyltrichlorosilane, tert-butyltrichlorosilane, isobutyltrichlorosilane, sec-butyltrichlorosilane, hexyltrichlorosilane, thexyltrichlorosilane, octyltrichlorosilane, decyltrichlorosilane, octadecyltrichlorosilane, cyclopentyltrichlorosilane, cyclohexyltrichlorosilane, phenyltrichlorosilane, styryltrichlorosilane, 2-cyanoethyltrichlorosilane, acetoxypropyltrichlorosilane, 3-acryloxypropyltrichlorosilane, 3-methacryloxypropyltrichlorosilane, chloromethyltrichlorosilane, 3-chloropropyltrichlorosilane, 3,3,3-trifluoropropyltrichlorosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltrichlorosilane, tetrachlorosilane, 1,2-bis(dimethylchlorosilyl)ethane, 1,2-bis(methyldichlorosilyl)ethane, 1,2-bis(trichlorosilyl)ethane, 1,6-bis(dimethylchlorosilyl)hexane, 1,6-(methyldichlorosilyl)hexane, 1,6-bis(trichlorosilyl)hexane, bis(dimethylchlorosilyl)norbornane, bis(methyldichlorosilyl)norbornane, bis(trichlorosilyl)norbornane, dimethylbromosilane, trimethylbromosilane, diethylbromosilane, ethyldimethylbromosilane, diethylmethylbromosilane, triethyibromosilane, vinyldimethylbromosilane, tripropylbromosilane, triisopropylbromosilane, tributylbromosilane, tert-butyldimethylbromosilane, di-tert-butylmethylbromosilane, tri-tert-butylbromosilane, triisobutylbromosilane, tri-sec-butylbromosilane, hexyldimethylbromosilane, thexyldimethylbromosilane, octyldimethylbromosilane, decyldimethylbromosilane, octadecyldimethylbromosilane, cyclopentyldimethylbromosilane, cyclohexyldimethylbromosilane, tricyclopentylbromosilane, tricyclohexylbromosilane, dimethylphenylbromosilane, methyldiphenylbromosilane, triphenylbromosilane, tert-butyldiphenylbromosilane, di-tert-butylphenylbromosilane, styryldimethyibromosilane, 2-cyanoethyldimethylbromosilane, acetoxypropyldimethylbromosilane, 3-acryloxypropyldimethyibromosilane, 3-methacryloxypropyldimethylbromosilane, bromomethyldimethylbromosilane, 3-bromopropyldimethylbromosilane, 3,3,3-trifluoropropyldimethylbromosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexyldimethylbromosilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyldimethylbromosilane, dibromosilane, methyldibromosilane, dimethyldibromosilane, ethyldibromosilane, diethyldibromosilane, vinylmethyldibromosilane, divinyldibromosilane, propylmethyldibromosilane, dibutyldibromosilane, tert-butylmethyldibromosilane, di-tert-butyldibromosilane, diisobutyldibromosilane, di-sec-butyldibromosilane, hexylmethyldibromosilane, thexylmethyldibromosilane, octylmethyldibromosilane, decylmethyldibromosilane, octadecylmethyldibromosilane, cyclopentylmethyldibromosilane, cyclohexylmethyldibromosilane, dicyclopentyldibromosilane, dicyclohexyldibromosilane, methylphenyldibromosilane, diphenyldibromosilane, tert-butylphenyldibromosilane, styrylmethyldibromosilane, 2-cyanoethylmethyldibromosilane, acetoxypropylmethyldibromosilane, 3-acryloxypropylmethyldibromosilane, 3-methacryloxypropylmethyldibromosilane, bromomethylmethyldibromosilane, 3-bromopropylmethyldibromosilane, 3,3,3-trifluoropropylmethyldibromosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexylmethyldibromosilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecylmethyldibromosilane, tribromosilane, methyltribromosilane, ethyltribromosilane, vinyltribromosilane, propyltribromosilane, isopropyltribromosilane, butyltribromosilane, tert-butyltribromosilane, isobutyltribromosilane, sec-butyltribromosilane, hexyltribromosilane, thexyltribromosilane, octyltribromosilane, decyltribromosilane, octadecyltribromosilane, cyclopentyltribromosilane, cyclohexyltribromosilane, phenyltribromosilane, styryltribromosilane, 2-cyanoethyltribromosilane, acetoxypropyltribromosilane, 3-acryloxypropyltribromosilane, 3-methacryloxypropyltribromosilane, bromomethyltribromosilane, 3-bromopropyltribromosilane, 3,3,3-trifluoropropyltribromosilane, 3,3,4,4,5,5,6,6,6-nonafluorohexyltribromosilane, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyltribromosilane, tetrabromosilane, 1,2-bis(dimethylbromosilyl)ethane, 1,2-bis(methyldibromosilyl)ethane, 1,2-bis(tribromosilyl)ethane, 1,6-bis(dimethylbromosilyl)hexane, 1,6-(methyldibromosilyl)hexane, 1,6-bis(tribromosilyl)hexane, bis(dimethylbromosilyl)norbornane, bis(methyldibromosilyl)norbornane, and bis(tribromosilyl)norbornane.
[0019] Examples of the amino-containing compound of formula (2) include ammonia, methylamine, ethylamine, propylamine, isopropylamine, allylamine, butylamine, pentylamine, hexylamine, octylamine, 2-ethylhexylamine, benzylamine, cyclopentylamine, cyclohexylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, 1,6-diaminohexane, aniline, toluidine, xylidine, naphthylamine, xylylenediamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, diallylamine, dibutylamine, dipentylamine, dioctylamine, di(2-ethylhexyl)amine, N-methylaniline, and diphenylamine.
[0020] Examples of the amino-containing compound of formula (3) include ethyleneimine, pyrrolidine, piperidine, pipecoline, piperazine, N-methylpiperazine, N-ethylpiperazine, morpholine, imidazole, triazole, and indole.
[0021] Preferably the silazane compound which is the target product and also serves as a solvent for the relevant reaction has the general formula (4), (5), (6) or (7).
[0000] R 1 n Si(NR 2 R 3 ) (4-n) (4)
[0000] Herein R 1 , R 2 , R 3 and n are as defined above.
[0000]
[0000] Herein R 1 , R 4 and n are as defined above.
[0000]
[0000] Herein R 1 and R 3 are as defined above, and n is 3.
[0000]
[0000] Herein R 1 and R 3 are as defined above, a is an integer of 2 to 20, preferably 3 to 10, more preferably 3 to 5, and n is 2.
[0022] The amount of the halosilane compound used is not particularly limited. From the aspects of reactivity and productivity, the halosilane compound is preferably used in an amount to give 0.1 to 4.0 moles, more preferably 0.2 to 3.0 moles of silicon-halogen bond per mole of the reactive N—H bond of the amino-containing compound.
[0023] In the reaction of a halosilane compound of formula (1) with an amino-containing compound of formula (2) or (3) to form a silazane compound, the same silazane compound as the reaction product is used as a solvent.
[0024] The silazane compound used as solvent may be the compound purified by removal of salt from and/or distillation of the synthetic reaction solution. From the aspect of quality of the final silazane compound, the silazane compound purified by distillation is preferably used.
[0025] The amount of the silazane compound used as a solvent is not particularly limited. From the aspects of reactivity and productivity, the silazane compound is preferably used in an amount of 0.1 to 10 moles, more preferably 0.5 to 5 moles per mole of the reactive N—H bond of the amino-containing compound.
[0026] In the silylation reaction of the amino-containing compound, a hydrogen halide forms as by-product. The hydrogen halide may be trapped using the amino-containing compound of formula (2) or (3) itself or another amine as a base. Suitable other amine compounds include trimethylamine, triethylamine, tripropylamine, tributylamine, ethyldiisopropylamine, pyridine, dimethylaminopyridine, dimethylaniline, methylimidazole, tetramethylethylenediamine and 1,8-diazabicyclo[5.4.0]undecene-7.
[0027] The amount of the other amine compound used is not particularly limited. From the aspects of reactivity and productivity, the other amine compound is preferably used in an amount of 0.3 to 10.0 moles, more preferably 0.5 to 5.0 moles per mole of the reactive N—H bond of the amino-containing compound.
[0028] Although the reaction takes place even in a catalyst-free system, a catalyst may be added for the purpose of promoting the kinetics of reaction. Examples of the catalyst include sulfuric acid, sulfonic acid derivatives such as methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, dodecylbenzenesulfonic acid and trifluoromethanesulfonic acid, hydrochloric acid, nitric acid, and salts of these acids. The amount of the catalyst used is not particularly limited. From the aspects of reactivity and productivity, the catalyst is preferably used in an amount of 0.0001 to 0.1 mole, more preferably 0.001 to 0.05 mole per mole of the reactive N—H bond of the amino-containing compound.
[0029] The reaction temperature is preferably 0° C. to 200° C., more preferably 10° C. to 180° C., though not limited thereto.
[0030] A solvent other than the silazane compound may be further added as long as this does not compromise the objects of the invention. Examples of the solvent include hydrocarbon solvents such as pentane, hexane, cyclohexane, heptane, isooctane, benzene, toluene and xylene, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, ester solvents such as ethyl acetate and butyl acetate, aprotic polar solvents such as acetonitrile and N,N-dimethylformamide, and chlorinated hydrocarbon solvents such as dichloromethane and chloroform. These solvents may be used alone or in admixture of two or more. The solvent is preferably used in an amount of 0.1 to 10 moles, more preferably 0.5 to 2 moles per mole of the silazane compound as solvent.
[0031] At the end of reaction, the amino-containing compound forms a hydrogen halide (typically hydrochloride) salt, which may be removed by any suitable techniques such as filtration of the reaction solution, and addition of water or an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide aqueous solution and subsequent separation. In the latter technique of adding an alkaline aqueous solution to the reaction solution, the amino-containing compound is liberated from the hydrogen halide salt of amino-containing compound, so that the amino-containing compound may be recovered. In this sense, the technique of adding an alkaline aqueous solution is preferred.
[0032] After the salt is removed from the reaction solution as mentioned above, the target product may be collected from the reaction solution using conventional techniques such as distillation.
EXAMPLE
[0033] Examples are given below by way of illustration and not by way of limitation.
Example 1
[0034] A flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 103.3 g (0.8 mole) of dimethyldichlorosilane, 200 g (0.99 mole) of bis(diethylamino)dimethylsilane as a solvent, and 0.38 g (0.004 mole) of methanesulfonic acid, and heated at 60° C. Once the internal temperature became steady, 245.6 g (3.4 moles) of diethylamine was added dropwise over 3 hours. The contents were stirred at the temperature for 1 hour. The reaction solution was cooled to room temperature, after which 400 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated and distilled, collecting bis(diethylamino)dimethylsilane as a fraction at a boiling point of 78° C./2.0 kPa. Amount 336.7 g, yield 84% (based on the weight of dimethyldichlorosilane). The yield of bis(diethylamino)dimethylsilane which was calculated based on the maximum weight of flask contents (i.e., the total weight of flask contents with 20 wt % sodium hydroxide aqueous solution added) was 144.0 g per kg of the maximum weight of flask contents.
Comparative Example 1
[0035] Reaction was performed as in Example 1 except that the solvent was changed to 200 g of toluene. A salt formed during dropwise addition of diethylamine, to inhibit stirring. It was necessary to add another 200 g of toluene. The reaction solution was cooled to room temperature, after which 400 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated, from which toluene was distilled off. By further distillation, bis(diethylamino)dimethylsilane was collected as a fraction at a boiling point of 78° C./2.0 kPa. Amount 133.9 g, yield 83% (based on the weight of dimethyldichlorosilane). The yield of bis(diethylamino)dimethylsilane which was calculated based on the maximum weight of flask contents (i.e., the total weight of flask contents with 20 wt % sodium hydroxide aqueous solution added) was 116.5 g per kg of the maximum weight of flask contents. Comparative Example 1 was less productive than Example 1.
Example 2
[0036] A flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 152.9 g (0.8 mole) of methylphenyldichlorosilane, 150 g (0.57 mole) of bis(diethylamino)methylphenylsilane as a solvent, and 0.38 g (0.004 mole) of methanesulfonic acid, and heated at 60° C.
[0037] Once the internal temperature became steady, 245.6 g (3.4 moles) of diethylamine was added dropwise over 3 hours. The contents were stirred at the temperature for 1 hour. The reaction solution was cooled to room temperature, after which 400 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated and distilled, collecting bis(diethylamino)methylphenylsilane as a fraction at a boiling point of 126° C./0.4 kPa. Amount 325.9 g, yield 83% (based on the weight of methylphenyldichlorosilane).
Comparative Example 2
[0038] Reaction was performed as in Example 2 except that the solvent was changed to 150 g of xylene. A salt formed during dropwise addition of diethylamine, to inhibit stirring. It was necessary to add another 180 g of xylene. The reaction solution was cooled to room temperature, after which 400 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated, from which xylene was distilled off. By further distillation, bis(diethylamino)methylphenylsilane was collected as a fraction at a boiling point of 82° C./1.0 kPa. Amount 174.0 g, yield 82% (based on the weight of methylphenyldichlorosilane).
Example 3
[0039] A flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 112.9 g (0.8 mole) of methylvinyldichlorosilane, 200 g (0.93 mole) of bis(diethylamino)methylvinylsilane as a solvent, and 0.38 g (0.004 mole) of methanesulfonic acid, and heated at 60° C. Once the internal temperature became steady, 245.6 g (3.4 moles) of diethylamine was added dropwise over 3 hours. The contents were stirred at the temperature for 1 hour. The reaction solution was cooled to room temperature, after which 400 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated and distilled, collecting bis(diethylamino)methylvinylsilane as a fraction at a boiling point of 82° C./1.0 kPa. Amount 344.7 g, yield 83% (based on the weight of methylvinyldichlorosilane).
Comparative Example 3
[0040] Reaction was performed as in Example 3 except that the solvent was changed to 200 g of toluene. A salt formed during dropwise addition of diethylamine, to inhibit stirring. It was necessary to add another 200 g of toluene. The reaction solution was cooled to room temperature, after which 400 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated, from which toluene was distilled off. By further distillation, bis(diethylamino)methylvinylsilane was collected as a fraction at a boiling point of 82° C./1.0 kPa. Amount 140.4 g, yield 82% (based on the weight of methylvinyldichlorosilane).
Example 4
[0041] A flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 120.6 g (0.8 mole) of triethylchlorosilane, 100 g (0.41 mole) of dibutylaminotriethylsilane as a solvent, and 0.38 g (0.004 mole) of methanesulfonic acid, and heated at 60° C. Once the internal temperature became steady, 217.0 g (1.7 moles) of dibutylamine was added dropwise over 3 hours. The contents were stirred at the temperature for 1 hour. The reaction solution was cooled to room temperature, after which 200 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated and distilled, collecting dibutylaminotriethylsilane as a fraction at a boiling point of 86° C./0.4 kPa. Amount 304.5 g, yield 84% (based on the weight of triethylchlorosilane).
Comparative Example 4
[0042] Reaction was performed as in Example 4 except that the solvent was changed to 100 g of hexane. A salt formed during dropwise addition of dibutylamine, to inhibit stirring. It was necessary to add another 100 g of hexane. The reaction solution was cooled to room temperature, after which 200 g of 20 wt % sodium hydroxide aqueous solution was added. The organic layer was separated, from which hexane was distilled off. By further distillation, dibutylaminotriethylsilane was collected as a fraction at a boiling point of 86° C./0.4 kPa. Amount 161.1 g, yield 83% (based on the weight of triethylchlorosilane).
[0043] Japanese Patent Application No. 2014-076769 is incorporated herein by reference.
[0044] Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims. | A silazane compound useful as synthesis intermediates for paint additives, polymer modifiers, pharmaceuticals and agricultural chemicals is efficiently prepared by reaction of a halosilane compound with an amino-containing compound in a solvent which is the same silazane compound as the target product. | 2 |
FIELD OF THE INVENTION
This invention relates generally to threaded fittings for use with pneumatic tubing or the like, and particularly concerns a threaded fitting design and construction which does not require the subsequent use of thread-sealing tapes or compounds to eliminate fitting fluid leakage around the fitting threads.
BACKGROUND OF THE INVENTION
It is common practice when installing pneumatic tubing fluid lines using threaded tube fittings to wrap the fitting threads with a sealant tape, such as a polytetrafluoroethylene ("Teflon") tape, or to coat such fitting threads with a liquid or paste-like sealant compound for leakage control purposes. In either case there is a substantial risk of possible subsequent defiling of cooperating pneumatic system components or fluids by loose or excess particles of the sealant utilized.
Based on experience derived from the practice of the invention described and claimed in this application, it is now known the total fluid sealing of pneumatic tube threaded fittings in an installation may be achieved without having to cover or coat the fitting threads with an adhering sealant.
Experience with the invention to date also establishes that the new and improved method of achieving fitting fluid sealing does not to any degree compromise otherwise obtained fitting full-flow, low-profile, and rapid installation characteristics, Also, the fitting design and construction disclosed and claimed herein permits subsequent re-use of the threaded fitting without having to replace the included captured ring seal and without having to utilize any of the aforementioned conventional sealant elements.
Additionally, when properly installed, the threaded fitting of this invention leaves no exposed threads to collect debris external to the system.
Other objects and advantages of the present invention will become apparent during a careful consideration of the detailed descriptions and drawings which follow.
SUMMARY OF THE INVENTION
The threaded fitting of this invention is basically comprised of a threaded male element having an included novel, doubly-tapered seal. A cooperating female thread, which may be typically incorporated into a fluid-receiving container, a flow-control device, a fluid coupling, or the like, has a threaded bore of proper size and with a chamfered bore entrance or opening of specified depth and taper. The threaded male element of the invention, which typically may have a connector, elbow, or tee configuration, and be either fixed or swiveled, has an external male thread of proper size and an included doubly-tapered captured ring seal that upon proper installation is compressed by the female thread tapered entrance. The included captured and doubly-tapered ring seal of the threaded male element is also compressed by a tapered groove portion of the male element body and by a flat under-surface of that body's nut-like body portion.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a preferred embodiment of the threaded fitting of this invention in a connector configuration;
FIG. 2 is a partially-sectioned view along line 2--2 of FIG. 1; and
FIG. 3 is a partially-sectioned elevational view but of another embodiment of the threaded fitting of this invention.
DETAILED DESCRIPTION
FIGS. 1 and 2 illustrate a threaded fitting assembly (10) which is constructed in accordance with this invention. Assembly (10) is basically comprised of a partially-threaded body element (12) and a doubly-tapered, ring-like or annular seal element (14) that typically is fabricated of a polytetrafluoroethylene ("Teflon") material. In addition, threaded fitting assembly (10), which has a so-called connector configuration, includes collet element (16) and an internal O-ring element (18) which are provided for sealably anchoring the end of a flexible fluids conductor such as a nylon tube or tubing element in assembly (10). Also as shown in FIG. 2, threaded body element (12) is provided with an integral external nut-like portion (20) as well as with the externally-threaded integral male body portion (22). Body portion (20) may alternatively have an external configuration different than the conventional hexagonal nut configuration illustrated, but in any event it must have an undersurface (41) of radial extent that defines the hereinafter described groove element (40). In most applications involving threaded fittings for tubing in the nominal external diameter size range of from one-eighth inch diameter to one-half inch diameter fitting body portion (22) is provided with a NPTF (National Pipe Thread-Fine) thread.
Threaded fitting assembly (10) is designed for cooperation with the schematic fluid system component illustrated and designated generally as (30) in FIG. 2. As suggested above, component (30) may have the function of a container for receiving or discharging fluids from or to the fluid line connected to fitting (10), or of a fluid flow control device, or of any other fluid-processing component in a fluids-handling system. System component (30) is provided with wall (32) having a threaded entrance bore (34). Entrance bore (34) in turn has an internal (female) thread (36) that has a thread configuration that corresponds to the thread configuration of fitting body portion (22) shown in FIG. 1.
In order to avoid the need for a sealant material such as a tape or liquid or paste-like sealing compound being applied to the threads of either fitting body portion (22) or receiving bore (32) and yet obtain total leakage elimination, and especially in the case of pneumatic system applications, threaded fittings (10) and threaded system component (30) are provided with a novel and extremely effective seal arrangement.
First, threaded fitting body element (12) is provided with a tapered annular groove (40). Groove (40) extends axially of fitting body element (12) a distance 'H' from the flat undersurface of body element nut portion (20) to the uppermost thread of threaded body element portion (22) and also extends inwardly of the thread root diameter by the radial thickness of seal element (14). In addition, the tapered surface of groove (40) is at an angle 'A' relative to the longitudinal axis of fitting assembly (10). For most intended applications of this invention it is preferred that the angle 'A' be in the range of from 10 degrees to 20 degrees.
Second, system component (30) is provided with an internal entrance chamfered surface (42) that essentially corresponds to the tapered surface of groove (40) in taper angle ('A') and axial extent ('H'). The radius of chamfer (42) essentially corresponds to the maximum radius of annular seal element (14).
FIG. 2 illustrates the fully-engaged relationship of threaded fitting assembly (10) with fluid system component (30) when properly combined. In such fully-engaged relationship, the material of doubly-tapered annular seal element (14) is totally isostatically compressed to provide complete sealing against fluid leakage through the pathways defined by the surfaces of thread portions (22 and 36). A portion of a flexible fluid tube (50) anchored in fitting assembly (10) is illustrated in FIG. 2.
In FIG. 3 I provide details of another embodiment of the present invention. Such embodiment is designated generally as 60 and differs from the embodiment of FIGS. 1 through 3 in that body element (12) is provided with an integral shoulder portion (62) which is positioned immediately below nut-like body portion (20) and intermediate that body portion and tapered groove element (40). This particular embodiment, while having the same sealing characteristics as embodiment (10), does obtain installation advantages in situations where the chamfered surface or entrance (42) to threaded opening (34) is not controlled as to depth and becomes excessive. As shown in the FIG. 3 installation, with the shoulder portion (62) included in fitting body (12) the shoulder portion engages chamfered surface (42) to complete seal effectiveness before the undersurface of nut-like body portion (20) makes contact with the upper or outer surface of component (30) and thereby prevents completion of the seal formation.
Preferably, in most applications fitting body element (12) is fabricated from a forged brass alloy and is subsequently often provided with a nickel plating as a protective finish. Other materials, component shapes, and component sizes may be utilized in the practice of this invention.
Since certain changes may be made in the above-described system and apparatus without departing from the scope of the invention herein and above, it is intended that all matter contained in the description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | An externally threaded fitting for use in coupling a fluid-conducting tube to a fluid-processing system threaded entrance opening is provided with a tapered-bottom groove immediately above and adjacent the fitting external thread, and with a doubly-tapered, polytetrafluoroethylene material seal element contained in the tapered-bottom groove. Upon proper installation in the system threaded entrance opening, the doubly-tapered seal element is fully isostatically compressed with total concealment of fitting external threads. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of provisional application Ser. No. 60/380,584, filed May 15, 2002, the disclosure of which is expressly incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
The present invention generally relates to protecting against unwanted root intrusion, plant growth, and root growth, and more particularly new methods and products for accomplishing same.
Roots from trees and shrubs are known to cause a variety of problems as well as damage to man-made infrastructure. For example, sanitary and storm drain systems in cities and other municipalities are aging with part of the problem induced by the roots of trees. The aging process involves physical cracks and joint dislocations, resulting in leakage of sewage and storm waters to soils, ground waters, and surface waters. A number of remedial relining methods are available. These work for a short period and are then degraded by plant roots seeking out moisture and nutrients, entering the lines, dislocating and degrading the linings, and thus creating the original problem. To counter this problem of plant-root intrusion, options have been used whereby liquid herbicide is simply flushed through the sewer lines or the sewer line is wrapped with a herbicide releasing fabric; however, the later needs to be done when the sewer line has been dug up for repairs or when new sewer lines are being laid.
New products and methods are needed to control the intrusion of roots not only into sewer and other pipes, but also into sidewalks, golf course areas, especially greens. The new methods and products also could be used to control weed growth in landscaping situations.
For piping systems, these methods and products should offer reduced transport of herbicide into the environment and reduced disturbance of the piping system. For sidewalks, golf courses, landscapes, etc., application of the product should disrupt the system rarely.
To meet these environmental and minimal-disruption requirements, the new products will make use of the ability of Trifluralin and related chemical compounds to stop roots from growing, thus repelling roots without necessarily killing the plants. The key difference between the new products/methods and conventional ones is sustained performance, usually over many years of product life.
Commercial applications for the new products include those cited above, plus control of plant/root growth in landscaped areas, roadside gravel areas, planter strips, stone walkways, brickwork patios and driveways. Soil stabilization can be achieved along with root control. These products can be applied during construction or in remedial situations.
ART
The following art has relevance to this invention as summarized below.
1. U.S. Pat. No. 5,069,706 proposes to flush a sewer line with a mixture of an organic herbicide, carbonate, and foam producing surfactant to inhibit flora growth. 2. U.S. Pat. No. 5,003,726 proposes to inhibit root growth around outlets of drip irrigation hose by introducing clay or the like into the line followed by a herbicide. The clay absorbs the herbicide for providing root growth protection. 3. U.S. Pat. No. 4,981,524 proposes a method to coat the upper inside of pipe with root-inhibiting foam. 4. U.S. Pat. No. 4,988,236 proposes a biocide containing tape for application to underground pipe. 5. U.S. Pat. No. 4,025,360 proposes an apparatus to coat the inside of pipe with foam. 6. U.S. Pat. No. 5,165,434 proposes an apparatus for blowing dry herbicide inside underground pipe. 7. U.S. Pat. No. 5,735,955 proposes an apparatus to coat the inside of pipe with foam. 8. U.S. Pat. No. 4,405,360 proposes to incorporate a porosigen (having a water solubility of between about 0.0005 and 100 g per 100 g of H 2 O) into a thermoplastic and/or thermoset polymer and herbicide to form a controlled release herbicide dispenser. Porosigens form pores by dissolving in water. The result is a growing tube structure that taps active ingredient that is stored in the matrix. 9. U.S. Pat. No. 4,284,444 proposes to prepare anti-bacterial, anti-fungal, etc., non-porous polymeric preforms by adhering a non-porous layer of a polymeric composition containing an anti-bacterial, anti-fungal, etc. agent that is capable of migrating into said preform so that such migration takes place. For example, a PVC preform has a PVC/CaCO 3 /DOP containing tri-n-butyl tin neodecanoate layer adhered to the preform for permitting the tin compound to migrate into the PVC preform. 10. U.S. Pat. No. 3,891,423 proposes a weed growth retardant product for woody plants of a sheet-like water-permeable fabric substrate (e.g., cotton, rayon, nylon, polyethylene, polypropylene) having adhered thereto a very slightly water-soluble film-forming binder (e.g., vinyl resins, insolubilized carbohydrates, aminoplast resins, insolubilized proteins, polyesters, polyethers, polyamides, polyurethanes) and a herbicide. 11. U.S. Pat. No. 3,096,167 appears to be a very early proposal for making biotextiles in that this patent generically claims incorporating a water-leachable, soil sterilant into a non-rigid fibrous carrier. 12. U.S. Pat. No. 4,360,376 proposes a very specific Pennwalt interfacial condensation polymerization system of microencapsulation. 13. U.S. Pat. No. 4,439,488 proposes encapsulation that uses aqueous gel formation as a key step.
14. U.S. Pat. Nos. 5,073,191, 5,160,530, and 5,317,004 propose an aqueous emulsion approach in which trifluralin is dispersed in a molten state. The capsules contain very small particles (down to 0.1 micron). Spray drying is involved. The polymorphism of trifluralin is exploited in these inventions.
15. U.S. Pat. No. 5,980,996 proposes to control of water flow, which is irrelevant to our goals. However, the method uses UV radiation to polymerize acrylates that can be partly neutralized and, thus, can be ionomers (although not identified as such in the patent). The substrates include our favorite fibers, but the penetration of monomer into the fiber does appear to be appreciated by the inventors. The use of the structure to hold compounds other than water also is not appreciated. 16. U.S. Pat. No. 3,676,441 proposes a specific class of chemicals. The specification, however, presents a number of ideas for making granules. The active ingredient can be mixed with polymerizable substances that are polymerized under conditions that do not affect the active ingredient. A prepared porous polymer is impregnated with a solution of the active ingredient followed by removal of the solvent. 17. U.S. Pat. No. 4,731,143 tells how to coat a geotextile with a thin polymer film. This patent does not mention active ingredients. This patent limits the polymer film to being an aqueous dispersion. 18. U.S. Pat. No. 5,389,432 tells how to deposit a binder selectively on the places where the fibers overlap while leaving the rest of the fabric mostly uncoated. This overlap-only feature could be useful for economizing on expensive active ingredients. 19. U.S. Pat. No. 5,534,304 describes how to cause a fabric to have extremely long flow-through times (90 days vs. 1 minute which is 129,600 to 1). Superabsorbent materials that are used to attain this result include polyacrylic acids, polyacrylamides with cross-linking via metal ions. These are not the same as ionomers. The super absorbent materials are applied as water-in-oil emulsions. The structures that are desired for this invention are tailored to sorb and hold water tenaciously. 20. U.S. Pat. Nos. 5,614,256 and 5,736,466 pertains to watertight, vapor-permeable, and flame-retardant coatings. The key steps are to make a stable foam from the blended ingredients, apply the foam to a fabric (geotextile), and then convert the foam into a continuous coating with the desired properties. 21. U.S. Pat. No. 5,942,006 is limited to cellulosic fabrics and a polymerizable organophosphate flame retardant. However, some claims include blends of cellulosic and synthetic fibers. 22. Japanese Patent No. 401221573A proposes to coat polypropylene fabric with an unsaturated carboxylic acid or its derivative, then irradiate with high energy beams followed by coating the fabric with a monomer then irradiating the solution with active high energy beams to effect graft modification. 23. Japanese Patent No. 401198346A proposes to impregnate a polyethylene net with acrylic acid and sodium hydroxide and irradiate with an electron beam to form a water absorbable sheet. 24. U.S. Pat. No. 5,116,414 and its division, U.S. Pat. No. 5,449,250, propose incorporating a herbicidal 2,6-dinitroanaline into a polymer to form a device, which is placed beneath the soil to release the 2,6-dinitroanaline over time. 25. U.S. Pat. No. 5,856,271 proposes to blend an active chemical (herbicide) with a moisture-free carrier (carbon black) and add the resulting product to a polymer preform, which then is formed into a release device. 26. U.S. Pat. No. 5,181,952 proposes a geotextile having discrete spaced apart nodules of carbon black and 2,6-dinitroanaline herbicide. 27. U.S. Pat. No. 5,898,019 proposes to fill cracks in pavement with a first polymer containing a pre-emergent herbicide and with a second polymer containing a systemic herbicide, and then hot seal coating the crack. 28. U.S. Pat. No. 5,139,566 proposes a geotextile having spaced-apart nodules formed from a liquid mixture of herbicide and binder, which mixture is injected into the geotextile. 29. U.S. Pat. No. 5,620,499 proposes a shaped water insoluble elastomer containing a fertilizer that releases the fertilizer at a controlled rate. 30. U.S. Pat. Nos. 5,883,046 and 5,733,848 produce microparticles of a rapidly leaching agrochemical within a polymer matrix of a cross-linked unsaturated polyester/vinyl polymer by forming a NAD of the agrochemical, unsaturated polyester, and vinyl ester resin followed by polymerization. 31. U.S. Pat. No. 5,985,010 proposes an animal repellent of capsicum and at least one liquid organic solvent in a cross-linked polymer resin. 32. U.S. Pat. No. 5,866,141 proposes to coat a polymer fabric with an agrochemical in admixture with an adhesive for application to a plant. 33. U.S. Pat. No. 5,130,342 proposes microporous thermoplastic polymeric articles (including fibers) that are particulate filled. 34. U.S. Pat. No. 5,093,197 proposes hollow fibers formed from ultra-high molecular weight polyolefin, which can be woven into fabric. 35. U.S. Pat. No. 6,150,019 proposes hollow polymeric fibers than can contain a dye. 36. U.S. Pat. No. 5,801,194 establishes the technical feasibility for epoxy resins as barrier coatings with several pesticides. 37. U.S. Pat. No. 6,099,850 proposes mixing an insecticide with a polymer to form a controlled release barrier. 38. U.S. Pat. No. 5,985,304 establishes the technical feasibility for epoxy resins as barrier coatings with several pesticides.
BRIEF SUMMARY OF THE INVENTION
One aspect of the present invention is a sprayable composition for coating pipe for protecting said coated pipe from one or more of root intrusion or root growth when said coated pipe is placed underground. Such sprayable formulation includes a 2,6-dinitroaniline herbicide; a polymer pellet impregnated with a 2,6-dinitroanililne herbicide-sorbed colloidal clay; and a film-forming polymer. Another aspect is pipe coated with the dried residue of a coating of a 2,6-dinitroaniline herbicide; a polymer pellet impregnated with a 2,6-dinitroaniline herbicide-sorbed colloidal clay; and a film-forming polymer, wherein the coated pipe is protected from one or more of root intrusion or root growth when the coated pipe is placed underground. As another aspect, an inflatable bladder can be coated with a coating of a 2,6-dinitroaniline herbicide; a polymer pellet impregnated with a 2,6-dinitroanililne herbicide-sorbed colloidal clay, and hung inside a pipe to protect it from one or more of root intrusion or root growth.
In a formulation of one or more of a polymer gel for repairing pipe, a grout for pipe, or a soil stabilizer, the improvement for one or more of root intrusion or root growth when said coated pipe is placed underground, is achieved by incorporating into the formulation, a 2,6-dinitroaniline herbicide and a polymer pellet impregnated with a 2,6-dinitroanililne herbicide-sorbed colloidal clay.
Improved geotextile fabric or landscape type fabric can be produced by incorporating into the fabric a formulation of a 2,6-dinitroaniline herbicide and a polymer pellet impregnated with a 2,6-dinitroanililne herbicide-sorbed colloidal clay.
Another aspect is an improved method for filling gaps in pavement for repelling unwanted invasion by plants by filling the gaps with a polymer matrix in which is dispersed a composite formed from a colloidal clay, a 2,6-dinitroaniline herbicide, and polymer composite.
Yet another aspect is an improved grout or gasket capable of repelling unwanted invasion by plants, which grout is an elastomer matrix in which is dispersed a composite formed from a colloidal clay and a 2,6-dinitroaniline herbicide.
Yet another aspect is a method for protecting pipe from one or more of root intrusion or root growth when said pipe is placed underground, includes the steps of infusing a cord with a 2,6-dinitroaniline herbicide-sorbed colloidal clay and hanging said infused cord inside said pipe, whereby vapors released from said infused cord protect said pipe from one or more of root intrusion or root growth.
Yet another aspect is a melt spinning process for manufacturing a geotextile wherein molten fiber-containing polymeric material is melt spun using spinnerets. This process includes blending particles bearing a 2,6-dinitroaniline herbicide-sorbed colloidal clay with a melt said polymeric material, the size of said particles allowing the blend to be melt spun.
Yet another aspect is an improved geotextile fabric wherein incorporated into said geotextile fabric is a formulation of hollow fibers containing a 2,6-dinitroaniline herbicide.
Yet another aspect is an improved geotextile fabric wherein the 2,6-dinitroaniline is incorporated into the fibers of the polymeric fabric after the fibers have been formed by soaking the fibers in a molten blend of the 2,6-dinitroaniline colloidal clay mixture.
ADVANTAGES OF THE INVENTION
This invention protects a territory from intrusion by roots of plants. It does so by repelling the roots, rather than killing the plant. It thus has ecological advantages over conventional herbicide root control methods that kill the plant. This consideration is important for protection of golf course greens against encroachment by trees that are needed as hazards, for example.
The products of this invention have a wide scope of application that includes soil stabilization with root control, decorative landscapes, roadside plantings, parks and playgrounds. The products save the user significant expenditures of labor that would be needed for repeated applications of less sustainable products.
The products of this invention can be installed once and used for many years. This saves the cost of materials and labor that would be devoted to repeated installations. It also avoids repeated disruption of the ground.
The slow release of Trifluralin into the environment not only reduces environmental damage, it also saves money and resources because less active ingredient is consumed.
Conventional herbicide applications lead to leaching and damaging runoff, which are avoided by use of this sustained release system. Thus, drinking water resources are protected.
Application of conventional herbicides can expose to toxicity dangers those who apply the herbicide. Other people and pets in the vicinity are also placed at risk. This sustained release system minimizes such risks.
The pipe embodiment is especially useful because the coating can resist biodegradation that occurs in sewers and other environments that contain diverse biotic species. The polyurethane formulations of this invention resist biodegradation by selection of appropriate polymers and by means of additives.
The barrier coatings of this invention include unsaturated polyesters and epoxy resins that are inexpensive and highly resistant to biological attack due to their crosslinked chemical structures. These materials are also strong and resist degradation due to weathering. These polymers thus contribute to the sustained performance of the products of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and advantages of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:
FIG. 1 schematically depicts the manufacturing steps for the sewer pipe embodiment of the present invention;
FIG. 2 graphically plots release rate profiles for Trifluralin contained within polyethylene (PE) granules associated with Acrylimide Gel;
FIG. 3 graphically plots the relationship between Acrylimide Gel Longevity and concentration of PE/Trifluralin and PU/Trifluralin carrier, wherein the values assume a 25% duty cycle, and show a 20% variation due to uncontrolled variables;
FIG. 4 schematically depicts the manufacturing steps for the unsaturated polyester barrier embodiment of the present invention;
FIG. 5 schematically depicts the manufacturing steps for the epoxy resin barrier coating embodiment of the present invention;
FIG. 6 schematically depicts the manufacturing steps for the geotextile embodiment of the present invention;
FIG. 7 graphically plots vapor transfer of Trifluralin from delivery cord/reservoir to receiving solutions;
FIG. 8 schematically depicts the manufacturing steps for the IPN geotextile embodiment of the present invention;
FIG. 9 schematically depicts the manufacturing steps for the polymer/Trifluralin melt spinning embodiment of the present invention; and
FIG. 10 schematically depicts the manufacturing steps for the hollow fiber embodiment of the present invention.
The drawings will be further described below.
DETAILED DESCRIPTION OF THE INVENTION
The root intrusion problems that affect sewer systems, sidewalks, golf courses, etc., can be treated effectively with herbicides. However, conventional sewer treatment only lasts for a few days or weeks. Most conventional systems for delivery of Trifluralin for appreciable lengths of time generate environmental burdens in the form of contamination of ground water. The few exceptions (e.g., BioBarrier I and II) are not suitable for application to pipes and other substrates of this invention.
Sustained release systems are needed that keep the roots away for years. Trifluralin is an outstanding herbicide for these uses, but the suggested embodiments could be applied to other 2,6-dinitroaniline herbicides and many other types of herbicides. In this patent application, the term “TRIFLURALIN” includes other 2,6-dinitroaniline herbicides and other root-growth/repellent herbicides.
The four inventive embodiments are:
1. Protect pipes (sewer, gray-water, storm) and pavement with sustained release formulations that contain TRIFLURALIN. 2. Manufacture geotextile fabrics are loaded with Trifluralin and have barrier coatings. 3. Load geotextile fabrics with Trifluralin after manufacture. 4. Load fibers with Trifluralin before they are used to manufacture geotextile fabrics.
Embodiment #1
Pipe and Pavement Protection
Protect sewer, gray-water, and storm system pipes from root intrusion by application of a coating that contains TRIFLURALIN. All types of pipe that can come in contact with roots are included, especially sewer pipes, irrigation pipes, storm water pipes, water pipes, and drain-vent-and-waste pipes. There are three distinct approaches to this embodiment.
Spray-Applied Sustained-Release Coatings
The apparatus that is the subject of General Chemical Company's U.S. Pat. No. 5,735,955 is a device that is used commercially. Thus, the embodiment of spraying material inside the sewer pipes is practical. The drawback of the current product is that it does not provide sustained protection from root penetration. The product of this invention is designed to overcome this drawback, as illustrated in FIG. 1 . As shown in FIG. 1 , a polyurethane prepolymer is prepared by reaction of an aromatic isocyanate (e.g., MDI) with a polyol. The prepolymer is mixed with Trifluralin-sorbed clay. By “Trifluralin-sorbed colloidal clay” or “2,6-dinitroaniline herbicide-sorbed colloidal clay” is meant colloidal clay particles sorbed with Trifluralin or a 2,6-dinitroaniline herbicide. Such sorbed colloidal clay particles even may be referred to as a colloidal clay-Trifluralin blend or mixture. Pellets are made from a molten polymer in which is dispersed Trifluralin-sorbed colloidal clay particles. The Trifluralin-loaded pellets are mixed with the Trifluralin-loaded polyurethane prepolymer. This product is applied to a pipe or other substrate by spraying with a catalyst so that the prepolymer cures to be a polymeric source of Trifluralin.
Previous work by Cataldo and Van Voris (U.S. Pat. Nos. 5,019,998, 5,116,414, 5,181, 592, 5,449,250, 5,744,423, and 5,744,423) and Van Voris, P., D. A. Cataldo, C. E. Cowan, N. R. Gordon, J. F. Cline, F. G. Burton and W. E. Keiens. 1988, “Long-Term Controlled Release of Herbicides: Root Growth Inhibition”; Pesticide Formulations, Innovations and Developments , eds. B. Cross and H. G. Scher, pp. 222–240; ACS Symposium Series 371, American Chemical Society, Washington, D.C.; D. A. Cataldo, E. S. Lipinsky, and P. Van Voris, 1999, “Long-Term Controlled-Release Pesticide Devices”; Controlled - Release Delivery Systems for Pesticides , Ed. Herbert B Sher, Marcel Dekker, Inc., New York, has shown that Trifluralin can be effective in prevention of root intrusion in soil environs for several decades. Polyurethane products, similar to those contained in this embodiment, demonstrated sustained release. The differences between the current embodiment and prior art is the use of a spray method to apply a polymer product that adheres to the sewer pipe in which the herbicide is dispersed both in the polyurethane and in plastic pellets that form part of the polymer product and exposure of the polyurethane product to sewage. A combination of Trifluralin neat and Trifluralin-containing polymer pellets is dispersed in a coating formulation and spray applied to the inside of pipe to form a durable coating that exhibits a dual release of Trifluralin.
A preferred polymer coating is polyurethane. By “polyurethane”, we mean the various polymers made by reaction of isocyanates with polyols, water, and other hydrogen donors. The polymers can have urea linkages, biuret linkages, allophanate linkages, carbodiimide linkages, and free isocyanates groups.
Other sprayable polymers are included in this invention, as described in Embodiment #2. Because of the intense microbial activity of the contents of sewers, it is essential for the design of the polyurethane focus on chemical structures that do not degrade over the life of the product. Resistance to microbial attack can be attained by use of selected isocyanates (e.g., aromatics) and polyols (e.g., sterically hindered ones) for production of the polyurethane and/or addition of agents that control microbial populations (e.g., bactericides).
EXAMPLE 1
In this example, sustained release of Trifluralin was demonstrated. Technical grade Trifluralin was loaded into thermoplastic urethanes at rates of 10–20% (w/w) without noticeable loss in polymer structure. Urethane loading and release rates were as follows: thermoplastic polyurethane released at a rate of 6 μg cm2/day when loaded to a 10% level. A casting urethane that was loaded with 10% Trifluralin released at 0.5 μg/cm 2 /day.
Estimated longevity without additional barrier could be 20 years. Use of the pellets could extend this longevity considerably.
EXAMPLE 2
The table below shows data obtained by loading polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) with Trifluralin at the indicated levels and exposing them to a test environment. The loading operation involved mixing the melted thermoplastics with Trifluralin and then injection molding them.
Material Loading Release PP 20–25% 21 μg/cm 2 /day PE 20–25% 38 μg/cm 2 /day PET 10–15% 2.5 μg/cm 2 /day
Pellets
The pellets of this invention that contain Trifluralin (see FIG. 1 ) can be made, for example, of a polyethylene (HDPE, LDPE, or LLDPE), polypropylene, polyesters (e.g., polyethylene terephthalate), rubber (natural or synthetic), nylon (Nylon 6, Nylon 66, or Nylon 610), colloidal clays (e.g., montmorillonite or bentonite), silicones, lactic acid polymers, cellulosic polymers (cellulose, cellulose acetate, cellulose acetate butyrate, carboxymethyl cellulose, hydroxypropyl cellulose), lignin, and polyurethanes (thermoplastic and thermoset), including water-curable polyurethanes.
Bladder Embodiment
Another embodiment of Embodiment #1 uses an inflatable bladder to create a small space near the wall of the pipe. The acrylimide gel or urethane formulation that contains very small Trifluralin pellets is pumped into place and polymerized. The result can be a chemical grouting that is applied to joints and cracks. Alternatively, the result could be an interior coating that is applied over selected lengths of the pipe.
This bladder method is currently used to kill roots in the interior of pipes. But the embodiment of using this system for sustained release of Trifluralin is novel. Also, the uses as a long lasting chemical grouting, discontinuous or continuous coating is novel.
Gel Repair Formulations
Polymer gels can be formulated to contain pellets of Trifluralin so that root intrusion can be prevented for extended periods of time. These gel products are especially useful in pipe repair. However, the scope of this application also extends to grouts and soil stabilization uses.
When special catalysts are used to cure acrylamide resins, a crosslinked product is formed that is named “Acrylimide gel”. The current state of the art includes dispersion of Trifluralin in this gel so that it can be used to repair cracks in pipes while providing root-repellent properties. This product is of limited use because the Trifluralin escapes too soon. This invention includes Acrylimide gel repair formulations in which the Trifluralin is contained in polymeric pellets for sustained release of this root repellent. The formulation also contains some Trifluralin in the gel phase so that the product begins its protection immediately.
EXAMPLE 3A
The preparation of two types of gels that contain polymeric TRIFLURALIN-loaded polymeric pellets is described in this example.
Acrylimide gels were prepared by mixing 1 part acrylimide to 1 part crosslinking catalyst. Microthene polyethylene (PE) pre-absorbed with Trifluralin was mixed into the acrylimide immediately prior to mixing with catalyst. The loading rate of polymer/Trifluralin into gel was 5.5% (w/v). Analysis of the PE reservoir indicated a Trifluralin loading rate of 7.02% (w/w). This amounts to 3.9 mg Trifluralin per cm 3 gel, or a total Trifluralin content of 0.39% (w/w). Cubes, approximately 3 cm 3 , of the acrylimide gel were cut from the formed gel. These were placed into 200 mL of either water or water plus 0.1% Tween 20 (a wetting agent, denoted in the figures and tables as “WA”). The latter optimized release and solubility of TRIFLURALIN. All studies conducted at 19–21° C.
Acrylimide gels were prepared by mixing 1 part acrylimide to 1 part catalyst. Thermoplastic polyurethane powders (PU) pre-absorbed with Trifluralin was mixed into the acrylimide immediately prior to mixing with catalyst. The loading rate of polymer/Trifluralin into gel was 5.5% (w/v). Analysis of the PU reservoir indicated a Trifluralin loading rate of 10.7% (w/w). This amounts to 5.9 mg Trifluralin per cm 3 gel, or a total Trifluralin content of 0.59% (w/w). Cubes, approximately 3 cm 3 , of the Acrylimide gel were cut from the formed gel.
EXAMPLE 3B
This example provides data on exposure of the samples to simulated environments. The samples were placed into 200 mL of either water or water plus 0.1% Tween 20 (a wetting agent, denoted in the figures and tables as “WA”). This agent optimized release and solubility of TRIFLURALIN. All studies conducted at 19–21° C.
These sample treatments were monitored for release rates over a 50-day period, to remove any fast release components, and to determine time to steady state. Release rates over this period ranged from 21 μg/day to 9 μg/day Trifluralin released/day for the water solution system, and 87 μg to 50 μg/day for the water plus WA. After the 7-day pre-extraction period, samples were transferred to fresh solutions and the release rates monitored over 50 days.
FIG. 2 provided the plots for the time dependent release rates for the two treatments between 2 and 50 days. For the water plus WA treatment release rate declined over the 7-day period to 8.9 μg TRIFLURALIN/day; for the water treatment release rates declined to 4.7 μg/day at day II. In both instances, the final release rates appear to at or near, steady state, indicating that the values can be used in subsequent performance calculations.
Release rates for the PU based TRIFLURALIN, were 3.2 and 6.6 μg TRIFLURALIN/day at steady state (5 days) for the water-only and the water/WA treatments, respectively.
EXAMPLE 3C
Using the raw release rate figures, and based on the amount of Trifluralin contained in the PE/Trifluralin load, performance behavior for the acrylimide gel system can be roughly estimated. The total release rate profile and the amount of total Trifluralin within the gel reservoir were used estimate the longevity under the “worst” conditions. For the water-alone system, estimated longevity was found to be 2029 days or 5.5 years. For the more stringent scenario where there is solubility enhancers within the flowing waters (i.e., soaps, wetting agents, etc.), the longevity drops to 1214 days or 3.3 years.
Longevity of a sustained-release device/system is controlled by the size of the reservoir, and the overall release rate of active per unit time from the reservoir. Under environmental and application conditions, other factors moderate performance (longevity). For the sewer/gel system, these include the amount of time that the gel is exposed to flowing/standing water, the composition of the waters (primarily Trifluralin solubility enhancers; i.e., wetting agents), and spatial position within the pipe with respect to the plant root penetration point (top, bottom).
The performance data derived from FIG. 2 was used to estimate performance under various system parameters. These calculations remain conservative, but are moderated by the practical variables of the system. The critical performance point is the need to maintain 2–5 ppm Trifluralin at the point where the growing plant root would contact the gel barrier or the soils adjacent to the gels. Prior efforts clearly show that Trifluralin is highly effective in preventing root elongation at 2–5 ppm for 95% of the plants tested. A few require 10 ppm Trifluralin to inhibit root growth.
The two values that control the system are reservoir size and release rate for the active. From the experimental study, we used a loading rate or reservoir which contained PE/Trifluralin at 5.2% (w/v), and a Trifluralin load of 7.02% (w/w) TRIFLURALIN, resulting in a reservoir size for Trifluralin of 3710 μg/mL gel (1 cm 3 ). Under these conditions, including 100% saturation with a large water-receiving reservoir, longevities range from 3.3 to 5.5 years. In practice however, the gels would not be exposed to a water reservoir 100% of the time. Using duty cycles (50 and 25%), the time that water would be expected to flow over and puddle over the gel, we can calculate a revised longevity. These range from 4.4 to 7.3 years for a 50% duty cycle, and 9.4 to 15.7 years for a 25% duty cycle.
The portions of the gel that line the top of the pipe can be expected to experience limited bulk water flow events. However, this gel component does experience saturated water vapor at all times. Thus there is a continue loss from the gel to air, and more importantly a likely diffusion of Trifluralin to the lower gel components. Thus we set a typical duty cycle of 10%, with a resulting longevity of 22–36 years.
A moderately conservative duty cycle for an acrylimide treated sewer with the PE/Trifluralin carrier, the 5-year longevity can be attained using a 3% load of PE/Trifluralin based on a Trifluralin content of 0.39% ( FIG. 2 ), but up to 5% PE/TN loads may be necessary where root intrusions are from aggressive plants such as willow and Kudzu.
The use of polyurethane (PU) carriers rather than the polyethylene carriers, results in an increase in Trifluralin reservoir size, and a reduction in Trifluralin release rates. This results in an increase in longevity of the filler gels to 7 years to 15 years. These longevities can be increased based on duty cycles as in the case of the PE gels. For applications where larger cracks in more inaccessible areas of larger sewer lines is a cost and access problem, better performance longevities may be desired, thus the PU/Trifluralin carriers may be preferred. FIG. 2 provides the calculated Trifluralin loading versus longevity.
The other critical parameter, aside from the reservoir and release rate, is the maintenance of a concentration of Trifluralin in both the gels, and in any water-saturated soils adjacent to a pipe leakage area, sufficient to inhibit root growth (5–10 ppm). Additionally, waters flowing over/through the gels will in fact leave the pipe via imperfections (cracks, etc.), and be deposited into adjacent soils. With a minimal release rate of 5 μg TRIFLURALIN/day per cubic cm of gel, Trifluralin would be sufficient to migrate to soils and create an added zone of protection. This could be important for low duty cycle applications, since the half-life of Trifluralin in soils in at least 45 days, and thus its accumulation there would be significant.
The chemical grout products include not only acrylimide gels, but also grouts prepared from N-methylacrylamides and polyacrylamides. In addition, acrylates, epoxies, phenolic resins, and amino resins can form chemical grouts to which Trifluralin-containing pellets can be added. Trifluralin-containing pellets also can be added to such inorganic grouts as silicates that use calcium chloride or formamide as curing agents. These grouts can be used not only for repair but also for soil stabilization in the numerous landscaping applications cited in this application.
The pellets can be made from the polymers that are described in the Pellet section presented just prior to Example 3.
This formulation can be applied by the bladder method described above. In addition, this acrylimide gel can be applied by other means as a preventive measure to prevent root intrusion at pipe joints. It can be used to make grouts and mortars for construction uses. For example, concrete blocks that are joined with mortar or bricks and mortar could benefit from Trifluralin content.
Many polymers other than acrylimide form strong gels used in grouting or soil stabilization. This invention includes other polymer gels that are compatible with TRIFLURALIN. As examples: The polyurethanes of the Bladder Embodiment described above can be considered gels that are useful in grouting. Acrylate gels are quite widely used. Epoxies now are available in gel form. Phenol formaldehyde resins form gels. Lignosulfonates form gels. Inorganic gels that are based on silicate technology were the original grouts and soil stabilizers. They could be improved by use of Trifluralin in pellet formulations to extend the longevity of the product.
Pavement Protection
Pavements include, inter alia, sidewalks, streets, highways, runways, walkways in landscapes, etc. Gaps in pavements occur frequently. They result from many causes, including freeze thaw damage, mechanical damage by people or vehicles using the pavement, mistakes in construction of the pavement, and intentional spaces as part of the landscape design.
Plants invade pavement gaps, exacerbating damage and spoiling esthetic values. Many patents have issued on approaches to protect pavements from these problems. A relevant patent is Van Voris, et al., U.S. Pat. No. 5,898,019, which covers Trifluralin in a polymer matrix. The composition may contain carbon black.
Attainment of sustained release of Trifluralin that is applied to gaps in pavements can be improved by using a clay/Trifluralin/polymer composite material. It can be made by sorbing Trifluralin into clay (e.g., montmorillonite) that is in colloidal form. The colloidal state is essential for best performance in longevity and reduced Trifluralin degradation, compared with carbon black and other fillers presented in the prior art.
The sorption process can use Trifluralin vapor that contacts and permeates into the tiny clay particles. A fluidized bed process is especially convenient for loading the particles. However, molten or dissolved Trifluralin also can be used for loading. The loaded clay is incorporated into a polymer matrix that is preferably polypropylene or polyethylene or polyester (e.g., PET). The composite material can be applied to the gaps in the pavement directly or as part of a product that includes a sealant.
Gaskets that Contain Trifluralin
The weakest point of resistance to plant root intrusion frequently is the seal between lengths of pipe. Gaskets that join the pipes usually are made of elastomeric materials. Incorporation of Trifluralin into gasket materials has been described by Cataldo and coworkers in U.S. Pat. No. 5,449,250. Longevity and effectiveness in preventing root intrusion at the gasket is attained in this invention by using a clay/trifluralin/elastomer composite material. It can be made by sorbing Trifluralin into clay (e.g., montmorillonite) that is in colloidal form. The colloidal state is essential for best performance in longevity and reduced Trifluralin degradation, compared with carbon black and other fillers presented in the prior art.
The sorption process can use Trifluralin vapor that contacts and permeates into the tiny clay particles. A fluidized bed process is especially convenient for loading the particles. However, molten or dissolved Trifluralin also can be used for loading. The loaded clay is incorporated into an elastomer matrix that is preferably butyl rubber, neoprene rubber, silicone elastomer, thermoplastic urethane elastomer, or other polymeric gasket material.
Embodiment #2
Barrier Coating Embodiment
Modify a geotextile fabric by applying a barrier coating that contains TRIFLURALIN. The barrier coating (e.g., thermoset) could be an unsaturated polyester or an epoxy resin.
Many landscape applications make use of geotextile fabrics that are made from cheap polyolefins (polyethylene, polypropylene) or recycled PET from soda pop bottles. There are three ways to put Trifluralin into a geotextile: incorporate Trifluralin while making the fabric; infuse Trifluralin into the fabric; and put Trifluralin into a barrier coating that is adhered to the fabric.
Barrier coatings and films are frequently used to control the release of active ingredients. They usually are Saran® materials that are satisfactory for medical and veterinary uses. However, they are much too expensive for the intended landscape applications. Therefore, a “poor man's Saran®” is the product to be used in this invention.
The two most promising candidates are unsaturated polyesters and epoxies. They are cheap, available, durable, and capable of trapping and holding Trifluralin strongly so that release is slow.
Unsaturated polyesters are very familiar products. Glass fiber reinforced plastics (e.g., Fiberglas® products) combine glass fiber with unsaturated polyesters to produce boat hulls, automobile body panels, etc. Geotextile fabrics are made of a polyester or polyolefins, instead of glass fibers, but there is a good analogy here.
Unfilled unsaturated polyesters also are used in cheap coatings in which high performance, such as pigmented coatings for marking highways, is required. Thus, this class of polymers is durable in bad weather and can withstand mechanical punishment. Because of the current applications cited above, unsaturated polyesters can provide rugged coatings that are heavily crosslinked so that Trifluralin can be trapped in a barrier matrix. FIG. 4 is a flow sheet for production and use of unsaturated polyesters for sustained release of TRIFLURALIN. The production process would consist of blending Trifluralin with a mixture of purchased unsaturated polyester (e.g., phthalic anhydride, maleic anhydride, and propylene glycol) and styrene. An initiator (e.g., a peroxide) is added as the mixture is coating the geotextile. The coated geotextile is heated enough to cause crosslinking. Needle punching is used to establish pathways for movement of water through the geotextile.
The next issue is whether the Trifluralin can be released at a rate that is slow enough to be useful for the intended landscape applications. U.S. Pat. No. 5,985,010 describes an animal repellent composition in which pepper extract is combined with various cross-linkable coating materials, such as synthetic rubber, natural rubber, epoxies, paint, and sealants. Wires are coated with this material to produce a product that repels rodents, such as rats, mice, and squirrels. Multilayer coatings were used to increase product life.
The animal repellent data show that these coatings have the type of flexibility that is needed. These data also show that these coatings store a significant amount of active ingredient. Note that the target for this repellent is an animal that differs greatly from a plant root and that the chemical structure of the pepper extract is very different from TRIFLURALIN.
U.S. Pat. Nos. 5,733,848 and 5,883,046 describe the specific use of unsaturated polyesters for microencapsulation of agricultural chemicals, especially herbicides. This prior art establishes that herbicides are able to diffuse slowly through selected unsaturated polyesters. Note, that there is a very real difference between herbicide in a microcapsule and herbicide in a coating. The microcapsule is a container in which countless herbicide molecules are in a continuous phase while herbicide molecules are trapped in the coating matrix in a barrier coating so that there is not any continuous phase of active ingredient.
Epoxy resins are thermoset polymers that are used to make protective coatings that have excellent barrier properties and are noted for their durability in severe environments. FIG. 5 shows a flow sheet for production of geotextiles that use epoxy coatings that are reservoirs for TRIFLURALIN. Liquid epoxy resins would be blended with molten Trifluralin or a solution (in toluene) of TRIFLURALIN. An amine curing agent would be added and the coating would be applied to the geotextile and cured in place.
Technical feasibility for epoxy resins as barrier coatings that can release insecticides has been established by Cataldo and Van Voris' experiments, as shown in U.S. Pat. Nos. 5,985,304 and 5,801,194. The results showed that the release rate was about 10% as great as that of other reservoir materials. The chemical structures of the tested insecticides were very different from the 2,6-dinitro-aniline structure of TRIFLURALIN.
EXAMPLE 4
Dow epoxy resin (DER, Dow Epoxy Resin, Dow Chemical Co., Midland, Mich.) 331 is dissolved toluene and mixed with a solution that contains GENAMID 235 and VERSAMID 115 and Trifluralin in methyl isobutyl ketone. The quantities of the epoxy resin and the two curing agents are 1-to-1 on a molar equivalent basis. After 15 minutes of stirring, the viscosity and temperature are within the normal range for room temperature spraying. The solution is sprayed onto a polypropylene geotextile. The solvent evaporates while the epoxy resin cures. The coating that results slowly exudes Trifluralin over a period of several years.
Embodiment #3
Geotextile Modification Embodiment
In this embodiment of the present invention, modification of a geotextile to incorporate Trifluralin can be accomplished in three ways:
Infusion
A solution of a carrier (e.g., benzoate or phthalate esters) and a herbicide (e.g., TRIFLURALIN) is formed and contacted with a geotextile (e.g., polypropylene or PET) to the point of over-saturation ( FIG. 6 ). The overloaded geotextile/herbicide is subjected to heat (e.g., 130°–140° C.) squeezing (pressure) to produce a bare geotextile impregnated product, which then is overcoated with a polymer (e.g., PVA/PVAc copolymer) to make the product safer to handle and easier to install. Needle punching of this product is required after the infusion of the geotextile has been completed such that the final product will allow water and air to pass through it much like the commercially available landscape fabrics. This product is intended to have sustained release properties (e.g., 15+years) for wrapping sewer line or sidewalks, to avoid root damage from woody plants. Trifluralin concentrations of about 3.5–4 oz of the polymer pre-processing formulation per square yard are desired for this product. In addition to these two applications, control of plant/root growth in landscaped areas, roadside gravel areas, planter strips, stone walkways, brickwork patios and driveway can be treated by this method.
EXAMPLE 5
Experiments were conducted in which Trifluralin was dissolved in a plasticizer/solvent, such as, methyl benzoate. This solution is contacted with a geotextile fabric that sorbs the mixture into its fibers. Then, most of the plasticizer is removed from fibers by heating and pressure. Some of it is retained within the geotextile and as a film that surrounds the fibers. The concentration can be increased by increasing both temperature and duration of the exposure of the geotextile to the solution.
Typical results are shown in the table below.
Plasticizer Loading of Polymers and Release Rates
Material
Loading
Release
PET
20–40%
6–12 μg/cm 2 /day
PP
30–50%
50–90 μg/cm 2 /day
PE
12–25%
15–22 μg/cm 2 /day
* plasticizer affects release rates (increase)
* barrier films can reduce release rate by factor of 12–30.
This embodiment is analogous to one of the technologies now used to dye polyester fibers and fabrics. Therefore, it has technical feasibility in placing some Trifluralin into the fibers.
The infusion embodiment can be improved. The geotextile fabric that contains Trifluralin could be coated with a barrier coating to reduce the rate of release of this herbicide. This revised embodiment also would put to use the Trifluralin that adheres to the surface of the fibers.
The choice of barrier coating would depend on cost considerations that usually preclude use of SARAN (PVdC) coatings or laminations. The barrier coatings that are more promising include the same unsaturated polyesters and epoxies that were discussed in the previous section of this report. These barrier coatings could contain TRIFLURALIN.
The modified embodiment could allow for more storage of Trifluralin per unit area. This extra storage might be needed to attain a goal of product longevity that could not be reached by fiber infusion alone or loaded-barrier coating alone.
Polyethylene Cord Embodiment
An infusion embodiment was generated in which commercially available polyethylene cord was infused with Trifluralin to obtain a loading of about 10% to 20%. The product is intended to maintain a vapor pressure of Trifluralin that is high enough to inhibit root intrusion.
EXAMPLE 6
The purpose of this example was to determine whether Trifluralin contained within polyethylene (PE) cords could transfer in the vapor state in sufficient quantities to transfer Trifluralin to wetted surfaces within the sewer line, particularly upper surfaces not in contact with periodic flowing waters. The objective was to suspend a Trifluralin delivery system (cord over long lengths of sewer pipe), and use this as a delivery means to inhibit root growth and/or re-penetration by transfer of Trifluralin to the growth region of roots. Aged cord containing 20% Trifluralin in PE was used.
Methods
Twelve (12) cm sections of ¼ inch extruded PE cord containing 20% Trifluralin (w/w) were suspended over 500 mL of two solutions contained within 1 L capped bottles. The cords were lightly washed with 90% MeOH to remove crystalline Trifluralin surface deposits. The receiving solutions consisted of either water wetted with 0.1% Tween 20®, or 80% MeOH. The cord was suspended approximately 6 cm from the solution surfaces.
At periodic intervals sub-samples were removed and analyzed by HPLC to determine Trifluralin accumulations. This continued until apparent steady state is reached, or when daily rates were constant.
Results and Discussion
FIG. 7 provides the release profiles over the 16-day study period. As noted, release rates, as determined by vapor transfer from the cord surface to the solutions ranged from 500 to 50 μg TRIFLURALIN/day for MeOH solutions; for water containing wetting agent, values ranged from 80 to 20 μg TRIFLURALIN/day. The differences over the 16-day period reflect simply the repletion of readily diffusible Trifluralin from the near surface of the cords. The difference between the two receiving solutions reflects the relative solubilities of the Trifluralin in the two solutions, and is affected by the rate at which the Trifluralin can be removed from the air (by receiving surfaces), and the rate of vapor replenishment from the cord/reservoir.
It is fully expected that these rates will decline over time frames of years, due to loss of Trifluralin from the near-surface of the reservoir/cord. Overall longevity of the system tested was estimated at approximately 44 years.
Infusion with Carrier Polymerization
This embodiment differs from the infusion embodiment in that the carrier is polymerizable ( FIG. 8 ) and following the heat squeezing operation is subjected to polymerization (e.g., UV or free-radical catalyst). The overcoating step may be unnecessary in this embodiment. Alternatively, a barrier coating that also contains Trifluralin could be used with this embodiment.
Much of the technical and cost problems of infusion embodiment arise from the difficulties in removal of plasticizer from the fiber without loss of undue amounts of Trifluralin and the degradation of the strength of the fabric due to plasticizer presence.
A novel solution involving the polymerization of the plasticizer that remains within the fiber ( FIG. 8 ) has been developed. Thus, a plasticizer is chosen that also is a monomer. It was determined that Trifluralin is quite soluble in ethyl methacrylate and lauryl methacrylate. Experiments indicated that these plasticizer/monomers are capable of carrying Trifluralin into PET fibers. Thus, technical feasibility is evident up to this point in the process.
The next step is to polymerize the methacrylate monomer that is within the fiber, using either UV radiation (preferred) or peroxide (if necessary). Polymerization of a monomer that is dissolved in a polymer matrix is well known in the polymer art as producing “interpenetrating polymer networks” (IPN). Therefore, technical feasibility that an IPN can be formed is assured. The formation of the IPN may allow the overcoating step to be omitted, which would be desirable.
V. Embodiment #4
Fiber Incorporation Embodiments
The two fiber incorporation aspects of this invention are incorporation during melt spinning and incorporation into hollow fibers.
Incorporation During Melt Spinning
This embodiment involves the manufacture of geotextile fabrics that contain TRIFLURALIN. The herbicide would be incorporated into the fibers during their production, for example, via melt spinning or spun bonding techniques. The products would compete with the BioBarrier® family of products.
The manufacture of geotextiles from polypropylene or PET or polyethylene is a melt spinning operation. Therefore, it is logical to consider adding Trifluralin to the melted polymer prior to fiber/fabric production ( FIG. 9 ).
The result would be a fiber that already contains the herbicide. The messiness of the infusion method of getting Trifluralin into the fiber is avoided. Use of a plasticizer is avoided.
The melt spinning or spun bonded processes that are used to make geotextiles use spinnerets with tiny holes through which the melt must pass. Clogging of these holes is a nightmare that geotextile producers work to avoid because of the downtime that results. Thus, addition of Trifluralin to the melt must yield a true solution or a dispersion of particles that are so small that they pass through the holes easily.
Geotextile fabrics must meet rigorous standards of strength, flexibility, and durability. Mechanical performance tests help to determine the capacity of the polymer—that is the percentage of Trifluralin that can be stored in the fibrous product. There is a related hurdle involved, which is the change in the mechanical properties of the fibers as the Trifluralin filler is released over time. A third technical parameter is the rate at which Trifluralin is released from the fibers, with the goal being a slow rate. There is a high probability that the fibers would require a barrier coating to reach the rate goal.
Unlike the other embodiments, fiber spinning subjects Trifluralin to high temperatures that could result in a hazardous work environment. The manufacturer would need to install special environmental safety equipment and take suitable precautions. Many companies handle hazardous vapors all of the time.
This aspect of the present invention overcomes these hurdles by use of one or more of the following methods:
1. Sorption of Trifluralin onto tiny carrier particles that can pass through the spinnerettes that are used for melt spinning. The carriers of use in this embodiment of the invention include polymer particles (e.g., epoxies and unsaturated polyesters) or colloids that are based on clays (especially montmorillonites) or silica (especially via sol gel processes), or alumina or carbon. 2. Choice of a polymer with a solubility parameter close to that of Trifluralin to assure solubility of the active ingredient in the polymer melt; 3. Use of melt spinning technologies that minimize the likelihood of spinneret clogging (e.g., electrostatic spinning). 4. Production of geotextile fabrics in which the TRIFLURALIN-loaded fibers constitute only a fraction of the total fibers in the product. The majority of the fibers will be those that contribute to the strength and other mechanical properties, while only the minimum percentage of the more expensive TRIFLURALIN-loaded fibers is used. 5. Control of release rate is obtained by use of appropriate polymer coatings.
The art reported in the Art section shows that dyes, for example, can be incorporated into polymer melts and spun into fiber form, thus confirming that this general embodiment is viable.
Incorporation into Hollow Fibers
This embodiment can be described as follows: Use hollow polypropylene or PET or polyethylene fibers as a reservoir for TRIFLURALIN. Transfer a melt of Trifluralin into this cavity using capillary action, vacuum, or pressure. The transfer may also be accomplished by use of a solution of Trifluralin in a volatile organic solvent. Use these fibers as some or all of the fibers in a geotextile product that would be made under a special contract with a geotextile producer. FIG. 10 sketches this process embodiment.
Hollow polypropylene or PET fibers are available now that are rugged and durable. They are air-filled and used as insulation in sleeping bags. The high quality of the sleeping bag product is not needed, but it does demonstrate the technical and commercial feasibility of basing this invention on hollow fibers. The particular hollow fiber product needs to be selected with respect to the diameter of the cavity and the thickness of the wall. Recycle PET would help to reduce costs and be more environmentally responsible.
Hollow fiber membranes are employed to transport liquids. The most suitable process for filling the fiber cavity will depend on the capillary behavior between molten Trifluralin (or Trifluralin solution) and the fiber wall. This loading process can be accomplished at relatively low temperature, in contrast to the fiber melt spinning embodiment.
These fibers could be incorporated into (or onto) a spun bonded sheet. Alternatively, a nonwoven fabric could be made from these fibers, mixed with other fibers. The other fibers can provide strength and other mechanical properties, while reducing the cost of the product. The nonwoven sheet could be coated with a barrier coating, if it is needed. The product could be needle punched to provide a geotextile.
While the invention has been described with reference to a preferred embodiment, those skilled in the art will understand that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In this application all units are in the metric system and all amounts and percentages are by weight, unless otherwise expressly indicated. Also, all citations referred herein are expressly incorporated herein by reference. | One aspect of the present invention is a sprayable composition for coating pipe for protecting it from one or more of root intrusion or root growth when the coated pipe is placed underground. Such sprayable formulation includes a 2,6-dinitroaniline herbicide; a polymer pellet impregnated with a 2,6-dinitroanililne herbicide-sorbed colloidal clay; and a film-forming polymer. Another aspect is pipe coated with the dried residue of a coating of a 2,6-dinitroaniline herbicide; a polymer pellet impregnated with a 2,6-dinitroaniline herbicide-sorbed colloidal clay; and a film-forming polymer, wherein the coated pipe is protected from one or more of root intrusion or root growth when the coated pipe is placed underground. | 3 |
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