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RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/841,674 filed Apr. 24, 2001, now U.S. Pat. No. 6,740,078, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
A. Field of Invention
This invention pertains to a method and apparatus for treating eye disorders associated with imperfections of a patient's eye and its disability to accommodate for near vision. More particularly, the present invention pertains to a method and apparatus for treatment of presbyopia by shaping an annular or extreme peripheral portion of the patient's cornea to increase its refractive power, preferably using automated laser equipment.
B. Description of the Prior Art
Normally, a sharp image of an object is produced by a person's eye when the image is correctly projected on the retina. The process of focusing the image on the retina is referred to as accommodation, and it describes varying the curvature of the lens to change its focal point. More specifically, objects disposed at distances exceeding a certain threshold (usually about 5 m) are seen clearly by a human eye with no accommodation required and the eye is relaxed. For objects closer than this threshold, the eye must accommodate by squeezing the lens to increase its thickness and change its focal point.
As a person gets older, the lens in his eye and its supporting structure, such as the ligaments or zonules lose elasticity and he slowly loses his ability to accommodate. As a result he can no longer see close objects clearly, i.e., he suffers near vision deficiency. This condition is known as presbyopia.
Until about ten years ago the conventional means of treating presbyopia was by use of positive lenses (in the form of eye glasses or contact lenses). Persons who also had other problems, such as myopia or astigmatism, used negative and cylindrical lenses, respectively. These people had to wear bifocal glasses or contact lenses, i.e., lenses with at least two different portions: a superior portion with one curvature and an inferior portion with another curvature. A person wearing these kinds of lenses has to get used to looking at far objects through the superior portion and looking at close objects (in order of 40 cm or less) through the inferior portion.
Eyeglasses are also known with lenses which change gradually from one portion to another so that the lenses have various zones, each zone being optimized for looking at objects within a particular distance range.
Wearing bifocal or multifocal glasses has several disadvantages. One disadvantage is that some persons can get dizzy from such glasses and in fact they can never get used to them. These people normally have two kinds of glasses: one for near vision and another for distant vision. Another disadvantage is that many people find glasses cosmetically unacceptable.
Contact lenses are generally more acceptable cosmetically then glasses. However it is difficult to make bi- or multifocal contact lenses and so at present as presbyopia sets in, some people with contact lens must resort to glasses as well for near vision.
Recently, new techniques have been developed that use lasers to change the optical characteristics of the cornea. Typically, these methods consist of reshaping the cornea by steepening portions thereof. Some methods and apparatus for performing laser surgery on the eyes are disclosed for example in U.S. Pat. Nos. 5,350,373; 5,425,727 6,129,722 and PCT Publication WO 00/27324 all incorporated herein by reference. All these reference disclose methods and apparatus for corrective eye surgery, such as presbyopia, in which a laser beam is directed at the cornea and an ablation is performed to remove material from the cornea thereby changing its optical transmission characteristics. These procedures are performed using one of two techniques. The first technique involves producing an ablation of the cornea in a central zone thereof. The central zone has a diameter in the range of 1.0–3.0 mm and the ablation causes the central zone to steepen thereby increasing its refractive power. This technique is based on the underlying theory that the central zone of the eye is used for close vision while a peripheral zone of the cornea is used for distant vision. This theory is attributed to the fact that the pupil of the eye is closed by a sympathetic reflex when the person looks at objects located closer than 40 cm. According to this theory, since the pupil opens or dilates for distant objects, the annular portion of the cornea must be used to see far objects.
In other words, some present laser surgical techniques are based on a theory that categorizes the cornea into two zones: a central zone of about 1.0–3.0 mm that is used for near vision (for objects up to 40 cm); and an annular zone extending from 3.0 mm that is used for distant vision. Based on this theory, for each type of vision problem, the eye of a person is corrected by ablating the appropriate zone without modifying the other zone. More specifically, according to this theory, presbyopia is treated by steeping only the zone extending from 1.0 to 3 mm of the cornea to augment the convergence power of this zone, thereby focusing close objects onto the fovea.
According to the second theory the mulitfocality of the central zone of the cornea is used to view objects at different distances. Accordingly, presbyopia can be corrected by partitioning the central zone of the eye into several regions, ablating these regions independently to obtain different curvatures, each curvature defining a different dioptic powers for the respective region. The multifocality thus obtained may be achieved by excimer laser ablation with tissue being removed from the central zone of the cornea at different depths for each optical region. A person can then use each of the regions to look at objects at corresponding ranges including near vision.
OBJECTIVES AND SUMMARY OF THE INVENTION
In view of the above, it is an objective of the present invention to provide a method and apparatus for treating eye disorders which are more effective then conventional methods and techniques.
A further objective is to provide an improved method which does not require expensive or difficult modifications to the existing eye treatment apparatus.
Yet a further objective is to provide an eye treating method and apparatus which can be adapted easily to treat different eye disorders using the novel as well as conventional techniques.
Other objectives and advantages of the invention shall become apparent from the following description.
The inventors have discovered that contrary to the theories described above, the central zone of the cornea defined as the pupillary area is used by the eye for distant vision while the peripheral zone of the cornea is used for near vision. More specifically, the inventors believe that near vision is produced by light passing through an annular zone extending between 5–10 mm or more of the cornea, said annular zone being disposed concentrically around the pupil. The remaining central zone of about 5.5 mm is used by the eye for distant vision.
Accordingly, the inventors believe that any corrective surgery for the treatment of near vision, such as presbyopia should be performed in this annular zone, increasing the light that passes through the pupil and improving the intermediate and near vision.. The inventors further believe sometimes that during the treatment of the peripheral zone of the cornea for near vision, the optical characteristics of the central zone of the cornea may also change. However, in patients who do not suffer from poor distal vision, such a change is undesirable. Therefore, as a secondary procedure, after the peripheral zone is corrected for near vision, the central zone or pupillary area is also corrected to neutralize any undesirable optical changes in the central portion of the cornea that may have occurred as a result of the peripheral ablation.
The amount of material removed from the cornea for ablation, the optical characteristics of the patient may be considered. For example, for patients having a large pupil, steeper cornea or deeper anterior chamber, less tissue resection is needed and the corneal periphery. For older patients, more tissue resection is needed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a plan view of a person's cornea indicating a central zone thereof that is subjected to near vision treatment in accordance with conventional techniques;
FIG. 1B shows a somewhat enlarged cross sectional profile of the central ablation performed by conventional techniques to treat a near vision deficiency;
FIG. 2A shows a plan view of a person's cornea indicating an annular zone thereof that is subjected to near vision treatment in accordance with the present invention;
FIG. 2B shows a somewhat enlarged cross sectional profile of the peripheral ablation for near vision treatment of the cornea performed in accordance with the present invention;
FIG, 2 C is similar to FIG. 2B but it also shows an additional central ablation performed in accordance with the present invention;
FIG. 3 shows a block diagram for a laser apparatus used to provide treatment in accordance with this invention;
FIG. 4 shows a flow chart for the operation of the apparatus of FIG. 3 ; and
FIG. 5 shows a cross sectional view of an eye with a cornea that has undergone peripheral ablation in accordance with this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1A , as mentioned above, prior to the present invention it was believed that for near vision the eye makes use of light entering the cornea through a central zone b having a diameter of about 3 mm. Accordingly, most prior art techniques consist of ablating tissue at various depths in the cornea in a central zone b extending between 1 mm and about 3 mm. A small spot of about 1 mm is not ablated. More importantly, the annular zone c extending from about 5 mm to 10+mm is not substantially ablated during this treatment. FIG. 1B shows a typical prior art profile resulting from central ablation. As can be seen in this profile, the central ablation is concentrated in the vicinity of the outer edge of zone b, i.e., at about 3 mm.
According to the present invention, the treatment should not be applied to the central zone of the cornea but to its outer peripheral zone. FIG. 2A shows a schematic view of the cornea with a central zone A of about 5.5 mm and an annular or peripheral zone B extending from 5.5 mm to 10+mm. A typical profile 100 resulting from peripheral ablation in this peripheral zone B is shown diagrammatically in FIG. 2B . This ablation profile 100 is selected to steepen at least a portion of this peripheral zone B and correct the near vision of the patient for presbyopia and other near vision deficiencies. The size and shape of this ablation profile 100 is determined using standard techniques well known in the art and will not be discussed in detail, however in making the ablation the following patient characteristics are relevant:
A. The pupillary size. An important advantage of the present invention is that a high refractive power peripheral cornea is obtained that allows more light to enter through the pupil.
Therefore the pupillary size of the patient is considered when deciding the depth of the peripheral ablation.
B. The preoperative corneal curvature. The flatter the cornea is the deeper the treatment is required in order to achieve the desired level in which the peripheral power of the cornea corrects the presbyopia.
C. The anterior chamber depth. This amount of light entering through the pupil is also dependent on the distance between the pupil and the peripheral cornea, where the ablation is performed. Therefore this distance is also be considered.
During peripheral ablation, the central zone A of the cornea is not subjected to any substantial treatment. However, during peripheral ablation, the optical characteristics of the central zone A may also change. Therefore, during, or preferably after the peripheral ablation resulting in profile 100 , central ablation is applied to the central zone A to restore the vision of the patient through this central zone to what it was prior to the ablation profile 100 . FIG. 2C shows the profile 102 of the ablation applied to the central zone A. As discussed above, the inventors believe that this central zone A is responsible for distant vision which may be normal in a patient with presbyopia. Alternatively, if the patient suffers from poor distant vision as well, and/or has other visual problems the ablation profile 102 may be shaped to correct these problems. It should be understood that in FIGS. 2B and 2C the profiles 100 and 102 are shown schematically only to illustrate the approximate positions of these ablations and not necessarily their actual shape or size.
FIG. 3 shows a block diagram for an apparatus 10 arranged and constructed to perform the near vision treatment. The apparatus 10 may be adapted to perform either LASIK or PRK type of surgery. The apparatus 10 includes a laser beam generator 12 which generates a laser beam L. The laser beam generator 12 may be an excimer or a solid state laser generator.
The laser beam L can be a broad beam, a scanning beam or a flying spot type beam and is directed by an optical network toward the eye E of a patient. The network may be manually adjusted using a manual control 14 to insure that the beam L is focused and directed properly on the cornea F.
The apparatus further includes a keyboard 16 , an automated control 18 (which is preferably is a microprocessor-based control) and a profile memory 20 . The keyboard 16 is used to enter various information about the patient and the surgical operation that is to be performed. Based on this information and other parameters programmed into it, the automated control selects an appropriate profile for the ablation to be performed. In other word, the automated control 18 relies on software to direct the laser beam precisely and determine the movements required to obtain the correct ablation depth, the number of zones for ablation and the diameter of ablation. A set of profiles for various vision problems may be stored in the profile memory 20 and the automated control 18 can access and retrieve these profiles as required. The automated control also operates the laser beam. The apparatus shown in FIG. 3 may be implemented using laser equipment from Autonomous Technology, VISX (Star 2 and Star 3), Laser Sight, Weavelight, Alegretto, Schwind, Bausch and Lomb, Keracor and Meditech Aesculap.
The procedure for performing ablation on a specific patient using the apparatus of FIG. 3 is now described in conjunction with the flow chart of FIG. 4 . In step 40 , the patient is examined to determine his current eye condition. For example a 55-year old male was found to have plano distant vision and presbyopia. Next, in step 42 it was determined that the treatment for patient's presbyopia required a +2.50 spherical diopter correction. As part of this determination, a complete optometric and ophthalmological examination is performed on the eye, including measurement of the corneal curvature, pupillary size, anterior chamber depth, topography map and ultrasound pachymetry. This information was fed to the automated control 18 which then determined the corresponding ablation profile required to generate the +2.5 spherical diopter correction. In step 44 the ablation process was initiated and the automated control performed the necessary peripheral ablation on the cornea of the patient. Since the +2.5 diopter correction is rather drastic, in step 44 the peripheral ablation profile was performed in two phases. A peripheral ablation of +1.5 spherical diopters was performed in the optical zone B from 6.0 to 9.0 mm. Then a second peripheral ablation of +1.50 diopters was performed in the optical zone B from 5.5 to 9.0 mm. The peripheral ablations are performed on the stromal tissues of the cornea.
As discussed above, a peripheral ablation of the cornea may adversely affect the central zone of the cornea. Therefore, in step 46 the optical characteristics of the eye are checked again. In step 48 a determination is made as to whether a correction is necessary for the central zone. For the subject patient, such a correction was necessary. Therefore, the apparatus of FIG. 3 was used to perform a central ablation to restore the optical characteristics of the central zone A. More specifically, in step 50 a central ablation of 42 microns centered on the pupil was performed. If the patient suffers from other visual impairments, such as hyperopia, additional or other treatment may be applied during this step 50 .
FIG. 5 shows a cross sectional view of the eye with peripheral ablation 100 positioned in a peripheral zone of the cornea in accordance with the present invention.
In summary, using the method and apparatus described, a high refractive power peripheral cornea is produced by ablating a peripheral zone of the cornea extending from about 5.5 up to 10 mm or more without substantially changing the refractive power of a central zone of the cornea. The ablation steepens this peripheral zone to augment its dioptic power, thereby allowing the eye to focus on close objects without the use of a lens. During this process, the central zone of the cornea is not treated to insure that the distant vision remains unchanged. Since the central zone is not touched during the peripheral ablation required to treat presbyopia, it need not be covered or otherwise protected. After the peripheral ablation is completed, the central zone may be ablated in order to revert it to its characteristics prior to the peripheral ablation.
Numerous modifications may be made to this invention without departing from its scope as defined in the appended claims.
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An apparatus and method are disclosed for treating near vision loss or deficiency, such as presbyopia. In contrast to conventional techniques, a peripheral ablation is provided in an annular zone of the cornea ranging from 5.5 to about 10+mm to increase the dioptic power of this peripheral zone. The central zone disposed within the peripheral zone of the cornea is left untreated, is corrected for other vision deficiencies or is corrected so that it reverts to its characteristics prior to the peripheral ablation.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority from application Ser. No. 61/122,866, filed Dec. 16, 2008, the disclosure of which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to drop balls for use in wellbore activities, as for example, completion systems and more particularly to completion systems for accurate placement of stimulation treatments in multiple zone wells.
BACKGROUND OF THE INVENTION
[0003] In typical wellbore operations, various treatment fluids may be pumped into the well and eventually into the formation to restore or enhance the productivity of the well. For example, a non-reactive “fracturing” fluid or “frac” fluid may be pumped into the wellbore to initiate and propagate fractures in the formation thus providing flow channels to facilitate movement of the hydrocarbons to the wellbore so that the hydrocarbons may be pumped from the well. In such fracturing operations, the fracturing fluid is hydraulically injected into a wellbore penetrating the subterranean formation and is forced against the formation strata by pressure. The formation strata is forced to crack and fracture and a proppant is placed in the fracture by movement of a viscous fluid containing proppant into the crack in the rock. The resulting fracture, with proppant in place, provides improved flow of the recoverable fluid, i.e., oil, gas or water, into the wellbore. In another example, a reactive stimulation fluid or “acid” may be injected into the formation. Acidizing treatments of the formation results in dissolving materials in the pore spaces of the formation to enhance production flow.
[0004] Currently, in wells, especially horizontal or lateral wells, with multiple production zones, it may be necessary to treat various formations in a multi-stage operation requiring repeated trips downhole. Each trip generally consists of isolating a single production zone and then delivering the treatment fluid to the isolated zone. Since multiple trips downhole are required to isolate and treat each zone, the completion operation may be very time consuming and expensive.
[0005] To overcome the above disadvantages with multi-trip zone isolation and treatment, as well as other problems, e.g. the viability of cement in long lateral wells, new techniques and apparatus have been developed which effectively provide a substantially intervention-free method and eliminates many of the disadvantages of prior methods.
[0006] One such system makes use of a series of sleeves/valves and packers spaced along the length of the lateral well allowing the isolation of multiple zones and their selective fracturing in a continuous operation. Typically the sleeves/valves are selectively opened by dropping balls from the surface to land on approximately sized sleeves to operate or open each sleeve at the appropriate time.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] A typical workstring used in techniques for multi-zone completions employs a float shoe and a landing collar assembly at the toe. This arrangement controls fluid through the ID of the workstring as it is being manipulated in the wellbore. Typically, positioned along the workstring as in the horizontal section of a well, are a series of sleeves/valves which can be manipulated/shifted by drop-ball technology. As noted, at the bottom of the completion string is the float shoe followed by a landing collar which is then followed by a hydraulically activated stimulation sleeve and laterally spaced along the workstring the desired number of packers and stimulation sleeves with ball seats installed. In the arrangement, the stimulation sleeves are positioned in order such that the ball seats are ordered from smallest to largest, the smallest seat being closest to the toe of the well. Once the completion string has been positioned such that the stimulation sleeves are located adjacent the zones to be treated, after a series of steps well known to those skilled in the art, the stimulation method can be commenced. For example, after treatment of the first zone, i.e., the zone closest to the toe of the well, a first ball is dropped at the beginning of the pad of the next zone's treatment and is pumped down to land on the corresponding ball seat. When the ball lands, the zone that was just treated is now isolated, the stimulation sleeve is opened and the treatment of the next zone started. The process continues, dropping the next sized ball for each stage, until all desired zones have been treated. Lastly, the balls are returned back to the surface by flowing into the well. If for some reason the balls do not return or if full ID access is desired, the ball/ball seats that are attached to the stimulation sleeves can be drilled or milled.
[0008] As noted above, in using the ball drop technology, the balls are of different sizes and it is important that the balls be dropped in the appropriate order.
[0009] Typically, the balls used in the drop ball techniques are made of plastics, such as phenolics, but can be made of composite materials.
[0010] In one aspect of the present invention, there is provided a drop ball for use in wellbore activities, comprising a generally spherical body, the spherical body carrying at least one identifier that has and/or can acquire information that can be accessed to determine at least one parameter related to the ball, a portion of the ball and/or at least one condition related to said wellbore.
[0011] According to another aspect of the present invention, there are provided drop balls which contain, carry or include tags, markers, or identifiers, each of which in a given ball has a unique identifier that can be scanned, read or otherwise determined using various techniques; e.g., various mobile devices permitting users to retrieve or leave digital information related to the drop ball and/or wellbore condition. For example, there exists tags or markers that can contain multiple layers of information in very small particles, e.g. smaller than the diameter of a human hair. These types of markers, identifiers, etc., can be incorporated into the drop balls of the present invention and, since they contain information related to various parameters of the drop ball and/or can “read,” “determine” or “identify” at least one downhole condition, are ideally suited to be “read,” “identified,” or “detected” by devices; e.g., mobile devices, such as handheld scanners which can be electronic, optical, etc.
[0012] According to a specific aspect of the present invention, there are provided drop balls which contain one or more RFID readable chips embedded therein. The RFID chips, which can be active or passive, can contain information such as the size of the ball and other information which is important to both inject the balls during the procedure as well as determine the status of conditions downhole as the drop ball(s) or cuttings therefrom return.
[0013] In one embodiment, it is contemplated that the drop balls of the present invention containing the RFID chips would generally have a plurality of such chips containing the same information such that if one of the chips of a given ball were destroyed, the information needed would still be available on one of the other chips in that ball or fragments of the ball. While active RFID chips could be employed, generally speaking, the RFID chips contemplated by the present invention would be passive, i.e. while not containing a battery the chips will be charged with enough energy to communicate with an RFID reader and provide the reader with the data stored on the tag.
[0014] The use of RFID chips as described above is desirable for many reasons, not the least of which being that because of the properties of radio frequency propagation, the RFID chips or tags do not need to be at line-of-sight with the reader.
[0015] As noted above, the tags or markers contained in the drop balls of the present invention can contain in transcript, digitized information such as the size of the ball, temperature and pressure limitations on the use of the ball, downhole conditions, etc. Indeed, it is contemplated that the tags or markers could be encrypted or encoded to detect or determine certain conditions in the subsurface and/or downhole environment and store that data such that when the drop ball or any portion thereof was returned to the surface, that data could be employed to advise the operators of corrective actions that may be necessary.
[0016] It is further contemplated that the tags or markers, including the RFID tags, would be dispersed throughout the drop balls such that in cases when it was necessary to mill or drill out the drop balls subsurface, one or more returning fragments from the ball would still contain all of the information stored on the marker, originally, or acquired in the downhole environment. It is contemplated that as technology advances, the tags or markers for use in the drop balls of the present invention may ultimately be nano particles facilitating their uniform incorporation into the drop balls.
[0017] The drop balls of the present invention can be made of any number of materials. In the case of the use of RFID chips, the limitation on the compositional makeup of the body of the ball is that the material is radio frequency transparent such that the RFID chip can be easily read. Accordingly, plastic such as phenolics, nylon, polyurethane, etc., could be employed. Additionally, composites could be employed to make the body of the drop ball, such composites including materials such as plastics reinforced with fiberglass, carbon fibers, metallic fibers, etc. It is also contemplated that the drop balls could be made entirely of metallic materials and the RFID encased in radio frequency transparent materials which could then be secured into recesses extending from the surface of the ball.
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A drop ball for use in wellbore activities, such as wellbores in oil and gas drilling, completion and/or production activities comprising a generally spherical body, the spherical body carrying at least one marker, which contains and/or can determine at least one parameter related to the drop ball, the wellbore and/or activities being conducted in the wellbore.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part of U.S. patent application Ser. No. 62,775 filed June 16, 1987 and now U.S. Pat. No. 4,790,204.
BACKGROUND OF THE INVENTION
This invention relates to an electric shift apparatus especially suited for use with a motor vehicle having an automatic transmission.
Motor vehicles since their inception have required some manner of gear change mechanism to satisfy the varying torque and speed requirements encountered during the typical duty cycle of a motor vehicle. For many years these gear change mechanisms were manual in the sense that they required an operator input from a shift lever or the like to effect each desired gear change ratio. More recently, so called "automatic transmissions have become popular in which much of the shifting is done without operator input in response to sensed speed and throttle opening parameters. These automatic transmissions typically include a mode select lever positioned on the transmission housing and movable between a plurality of selectively pivoted positions corresponding to a respective plurality of shift modes within the transmission. The mode select lever is pivotally moved between its several shift positions by a cable or linkage mechanism extending from the mode select lever to a suitable gear selector lever located in the passenger compartment of the vehicle. Various proposals have been made in the past to eliminate the mechanical interconnection between the driver operated lever and the mode select lever and provide instead an electrical signal generated by a suitable action on the part of the driver and transmitted electrically to some manner of power means arranged to move the mode select lever. None of these attempts to provide an electric shift mechanism for an automatic transmission of a motor vehicle have met with any degree of commercial success since they provided a slow or imprecise shifting action and/or have generated excessive warranty and maintenance costs.
SUMMARY OF THE INVENTION
This invention is directed to the provision of an electric control apparatus for the automatic transmission of a motor vehicle which provides positive and precise shifting, which is amenable to ready installation in the motor vehicle at the time of the original motor vehicle manufacture, and which is reliable in operation even over a long motor vehicle life.
The invention electric control apparatus is intended for use with a motor vehicle having an automatic transmission of the type including a mode select lever driven by a motor and a kick-down lever driven by a solenoid positioned outside of the transmission housing and mounted for pivotal movement at one end thereof about a common axis.
According to a feature of the present invention, the electrical control apparatus for control of an automatic transmission receives input signals corresponding to the desired transmission state and the present state of the transmission, and includes a logic control unit for determining if the desired transmission state differs from the present transmission state, and for generating a clockwise motor drive signal if the desired transmission state is clockwise of the present transmission state and a counter-clockwise motor drive signal if the desired transmission state is counter-clockwise of the present state, in the case in which the desired transmission state differs from the present transmission state, and includes a motor drive circuit connected to the motor driving the mode select lever for rotating this motor clockwise in response to the clockwise motor control signal and rotating this motor counter-clockwise in response to the counter-clockwise motor control signal.
According to a further feature of the present invention, the electrical control apparatus receives vehicle condition signals corresponding to operational conditions of the motor vehicle and the logic control unit inhibits the generation of either the clockwise motor control signal or the counter-clockwise motor control signal when the desired transmission state and the vehicle condition correspond to one of a selected set of unsafe circumstances. These unsafe circumstances may involve a vehicle speed greater than a predetermined vehicle speed corresponding to the desired transmission state. The vehicle condition signals may include a plurality of speed signals, each speed signal being active when a corresponding predetermined vehicle speed is exceeded.
According to a further feature of the present invention, the automatic transmission includes the transmission states of park, reverse, low 1 and low 2, and the logic control unit inhibits generation of either the clockwise motor control signal or the counter-clockwise motor control signal when a first vehicle speed signal indicates the speed of the motor vehicle exceeds a speed of approximately three miles an hour and the desired transmission state is park, a second vehicle speed signal indicates the speed of a motor vehicle exceeds a speed of approximately seven miles per hour and the desired transmission state is reverse, a third speed signal indicates the motor vehicle speed exceeds a speed of approximately twenty miles an hour and the desired transmission state is low 1 and a fourth speed signal indicates the speed of the motor vehicle exceeds a speed of approximately thirty miles an hour and the desired transmission state is low 2. These particular speeds have been selected for the particular vehicle of the preferred embodiment and other speeds would be selected as appropriate for another vehicle. In accordance with the present invention the four vehicle speed signals are simultaneously generated from a analog speed signal through a set of comparators, each comparator comparing the analog speed signal to a corresponding threshold level.
According to a further feature of the present invention, the logic control unit includes a timer for inhibiting generation of either the clockwise motor control signal or the counter-clockwise motor control signal if the desired transmission state differs from the present transmission state for longer than a predetermined period of time. This predetermined period of time is set to ensure that the desired transmission state would be reached under ordinary operations. Thus, exceeding this predetermined period of time indicates that some type of improper operation has resulted. Accordingly, the logic control unit ceases generation of the respective motor control signals under this condition.
According to a further feature of the present invention the motor driving the mode selection lever of the automatic transmission is electrically braked when neither the clockwise motor control signal nor the counter-clockwise motor control signal is generated.
According to a further feature of the present invention, the desired transmission state signal is generated by the manual actuation of one of a set of push-button switches, each push-button switch corresponding to one state of the automatic transmission. The electric control apparatus further includes a plurality of indicators, one disposed proximate to each of the manual push-button switches, one of the indicators being actuated in accordance with the transmission state signal. These indicators are preferably light emitting diodes connected to a variable illumination supply voltage, whereby their intensity is varied in accordance with the illumination intensity of other control instruments.
According to a further aspect of the present invention, the electrical control apparatus further includes a manual control enabling a generation of either the clockwise motor control signal or the counter-clockwise motor control signal. The manual control preferably includes a first momentary contact switch for generation of the clockwise motor control signal and a second momentary contact switch for generation of the counter-clockwise motor control signal.
According to a further feature of the present invention, the electrical control apparatus further includes an accelerator pedal switch indicating full depression of the accelerator pedal and the logic control unit generates a signal for actuation of the solenoid driving the kick-down lever upon actuation of the accelerator pedal switch.
In accordance with the preferred embodiment of the present invention the motor drive circuit provides dynamic braking. When a clockwise control signal is generated, the motor drive circuit applies electric power to the motor in a first polarity for clockwise motion. When a counter-clockwise control signal is generated, the motor drive circuit applies electric power to the motor in the opposite polarity for counter-clockwise motion. If neither signal is generated, the motor drive circuit dynamically brakes the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a motor vehicle embodying the invention electric shift apparatus;
FIG. 2 is a fragmentary view looking in the direction of the arrow 2 in FIG. 1;
FIG. 3 is a perspective view of a power module employed in the invention electric shift apparatus;
FIG. 4 is a fragmentary cross-sectional view taken on line 4--4 of FIG. 3;
FIG. 5 is a fragmentary view taken in the direction of the arrow 5 in FIG. 3;
FIG. 6 is a cross-sectional view taken on line 6--6 of FIG. 4;
FIG. 7 is a perspective view of a bracket employed in the power module of the invention;
FIG. 8 is a fragmentary perspective view of a control module employed in the electric shift apparatus of the invention;
FIG. 9 is a circuit diagram for the invention electric shift apparatus;
FIGS. 10, 11 and 12 are views of an alternate form of encoder mechanism for use in the invention electric shift apparatus;
FIG. 13 is a view of a modified lever assembly for use in the invention electric shift apparatus;
FIG. 14 is a view of a modified system for mounting the invention control module in the vehicle;
FIG. 15 is a schematic view of the electrical control system of the present invention;
FIG. 16 is a more detailed schematic view of the speed analog-to-digital converter illustrated in FIG. 15;
FIG. 17 is a schematic view of a typical indicator lamp circuit including its connection to the variable illumination supply;
FIG. 18 is a schematic view of the timing circuit which ensures that the motor control signals are not generated for longer than a predetermined period of time;
FIG. 19 is a schematic diagram of the motor drive circuit; and
FIG. 20 is a somewhat schematic view of a roostertail member embodied in the transmission of the vehicle and illustrating the operation of the encoder mechanism to indicate the exact center of the range for each gear selected.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The electric shift apparatus including the electrical control system of the present invention is seen schematically in FIG. 1 in association with a motor vehicle of the type including an instrument panel assembly 10 positioned within the passenger compartment of the motor vehicle; a steering wheel 12 associated with the instrument panel; an accelerator pedal assembly 14; and an automatic transmission assembly 16 including a torque converter 18 and a transmission 20. Transmission 20 includes a mode select lever 22 and a kick-down lever 24 each mounted externally of the transmission housing for pivotal movement at one end thereof about a common axis. Specifically, kick-down lever 24 is fixedly mounted at its lower end on a shaft 26 and mode select lever 22 is fixedly mounted at its upper end on a tubular shaft 27 (see FIG. 2) mounted concentrically on shaft 26. It will be understood that selected pivotal movement of mode select lever 22 rotates tubular shaft 27 to operate internal devices within the transmission to position the transmission in a plurality of transmission modes such as park, neutral, drive, etc., and that pivotal movement of kick-down lever 24 rotates shaft 26 to operate internal devices within the transmission to the next lower gear for passing purposes or the like.
Power module 28 is adapted to be bolted to the transmission in proximity to levers 22 and 24 and includes a bracket 32, a motor assembly 34, and a solenoid 36.
Bracket 32 may be formed as a die casting and includes a planar main body portion 32a, lug portions 32b and 32c and a flange portion 32d. Bracket 32 is readily bolted to the housing of transmission 20 by bolts 38 passing through lugs 32b and 32c for threaded engagement with threaded bosses 20a and 20b on the transmission housing, and by a bolt 40 passing downwardly through an aperture in a flange 32 on the transmission housing for threaded engagement with a lug 20c on the transmission. Bosses 20a and 20b and lug 20c are already present on a typical automatic transmission housing and therefore need not be especially provided to carry out the invention.
Motor assembly 34 includes a DC electric motor 42, a speed reduction unit 44, and a lever assembly 46.
Motor 42 is direct current and may for example have an output torque rating of 200 inch pounds.
Speed reduction unit 44 is suitably secured to motor 42 and includes a housing 48, a cover plate 50 having a central hub member 50a, a worm gear 52 co-axial with the output drive of the motor 42, a worm wheel 54 driven by worm gear 52, and an output shaft 56 driven by worm wheel 54 and journalled in cover plate 50 and in an end wall 48a of housing 48.
Lever assembly 46 includes a first lever 58 secured by a nut 60 to the free end of speed reduction unit output shaft 56, and a second lever 60 secured by pivot means 62 to the free end of lever 58. Lever 60 is a compound member and includes sections 60a and 60b. Section 60b telescopically receives section 60a and with a pin 60c carried by section 60a guiding in a slot 60d in section 60b to allow the two sections to move axially relative to each other to vary the effective length of lever 60. The two sections may be locked in any selected position of adjustment by a nut 63 carried by pin 60c. The free end of lever 60 comprises a plastic snap fitting 60e for snapping engagement with a ball fitting 22a on the free end of mode select lever 22.
A modified version of compound lever 60 is shown in FIG. 13. In the arrangement of FIG. 13, lever section 60b of compound lever 60 is itself a compound member including a first member of 60f and a second member 60g. Member 60f is connected by slot 60d and pin 60c to lever section 60a and defines a central cavity 60h. Member 60g carries snap fitting 60e at its free end and is slidably received at its other end in cavity 60h with a pair of matched coil springs 64,65 positioned in cavity 60h and engaging opposite sides of a piston member 60i mounted on member 60g in cavity 60h.
The motor assembly 34 is mounted on the outboard face of the planar main body portion 32a of bracket 32. Specifically, motor 42 is mounted to the outboard face of bracket portion 32a by a bracket 66 and speed reduction unit 44 is mounted to the outboard face of bracket portion 32a by a plurality of circumferentially spaced bolts 68 passing through apertures 32e in bracket 32 and through suitable apertures in speed reduction unit cover plate 50 for engagement with threaded bosses 48b spaced circumferentially about housing 48. In assembled relation, the hub portion 50a of cover plate 50 passes through aperture 32f in bracket 32 to position lever 58 on the inboard face of the bracket.
Solenoid 36 may comprise for example a pull type unit capable of generating three pounds of pull and having a stroke of between three-eighths and one-half inch. Solenoid 36 is secured to the inboard face of planar main body portion 32a of brackets 32 by a clamp 69. A cable 70 is secured to the plunger 71 of the solenoid and a plastic snap fitting 72 is secured to the free end of cable 70.
Power module 28 further includes an encoder assembly 73 operative to sense the shift position of the transmission and generate an encoded signal representative of the sensed shift position.
Encoder assembly 73 includes an encoder wheel 74 and a pick-up device 76. Encoder wheel 74 may be formed for example of a suitable plastic material with conductive coating and is positioned on a side face of worm wheel 54 within the closed and sealed interior chamber 78 defined by housing 48 and cover plate 50. Encoder wheel 74 includes a central aperture 74a passing speed reduction unit output shaft 56 and further includes code indicia 80 provided on the exposed outer face of the wheel and arranged along four arcuate tracks 80a, 80b, 80c and 80d centered on the center line of the encoder wheel.
Pick-up device 76 includes a body member 82 mounting a plurality of flexible resilient contact fingers 84 for respective coaction with indicia tracks 80a, 80b, 80c and 80d. In addition to the four fingers 84 for respective engagement with the four indicia tracks, a fifth finger is provided to provide a ground for the system.
A lead 86 from motor 42 and a lead 88 from pick-up device 76 are combined into a pin-type plug 90 and a lead 92 from solenoid 36 terminates in a pin-type plug 94.
Control module 30 is intended for ready installation in an opening 10a in instrument panel 10 or a center console disposed between the two front seats by insertion of the module from the rear of the housing and fastening of the module within opening 10a by the use of several fasteners such as seen at 96. Module 30 includes a housing structure 98 of general box-like configuration enclosing an operator access or push-button submodule 30a and a logic submodule 30b.
Push-button submodule 30a includes a plurality of push-buttons 100 positioned in vertically spaced relation in the front face 98a of the module housing and corresponding to the available transmission shift modes. Specifically, buttons 100 include buttons corresponding to park, reverse, neutral, overdrive, drive, second and first shift positions for the transmission. Buttons 100 coact in known manner with a printed circuit board 102 to generate suitable electrical signals in response to respective depression of the buttons 100.
Logic submodule 30b includes an electronic printed circuit board 104 suitably electrically connected to printed circuit 102 and suitably mounting a first plurality of connector terminals 106 and a second plurality of connector terminals 108. Connector terminals 106 coact with a pin-type plug 110 at the end of a cable 112. Cable 112 includes plugs 114 and 116 at its remote end for plugging receipt of plugs 90 and 94 so that plug 110 embodies the information from leads 86, 88 and 92. Connector terminals 108 coact with a pin-type plug 118. Plug 118 embodies the information from leads 120, 121, 122, 123, 124, 125, 126, 128 and 129. Lead 120 is associated with a switch 130 sensing the open or closed position of the driver's door of the vehicle; lead 121 is associated with a switch 132 sensing the presence or absence of a driver on the driver's seat of the vehicle; lead 122 senses the open or closed condition of the ignition switch 134 of the vehicle; leads 123 and 124 are connected to the negative and positive terminals of the vehicle battery 135 with a suitable fuse 136 in lead 123; lead 125 is connected to a speed sensor 137 which provides information with respect to the instantaneous speed which the vehicle is traveling; and lead 126 is connected with a switch 138 which is closed in response to movement of throttle lever 139 to its extreme open throttle position by a cable 140 connected in known manner to the accelerator assembly 14 of the vehicle. Lead 128 is connected with brake switch 133 which senses whether or not the brake is actuated. Lead 129 is connected with seat belt switch 135 which senses whether or not the driver's seat belt is fastened.
The electric shift assembly is delivered to the vehicle manufacturer in the form of power module 28 and control module 30. During the assembly of the vehicle, the power module 28 is mounted on the transmission housing proximate the control levers 24 and 26 and the control module 30 is mounted in the instrument panel 10, whereafter plugs 90 and 94 are plugged into plugs 114 and 116 and plugs 110 and 118 are plugged into control module 30 to complete the assembly of the invention electric shift apparatus.
The mounting of power module 28 on the transmission housing is accomplished simply by passing bolts 38 through bosses 32b and 32c for threaded engagement with transmission housing bosses 20a and 20b, passing bolt 40 through lug 32d for threaded engagement with transmission housing lug 20c, and snapping snap fittings 60e and 72 respectively over ball fitting 22a on the free end of mode select lever 22 and a ball fitting 24a on the free end of kick-down lever 24. As the lever assembly 46 is connected to the mode select lever, lever sections 60a and 60b of lever 60 move telescopically and selectively relative to each other to provide the precise effective length of length 60 to allow positive snapping engagement of snap fitting 60e over ball 22a irrespective of manufacturing tolerances, whereafter nut 64 is tightened to lock the lever 60 in its precise adjusted position.
Installation of control module 30 in instrument panel 10 is affected simply by moving the control module from the rear of the panel into the opening 10a and fastening the module in place by the use of fasteners 96 or the like. Following the plugging of plugs 90 and 94 into plugs 114 and 116 and the plugging of plugs 110 and 118 into connector terminals 106 and 108, the system is operational and ready for use.
Alternatively, in situations where space immediately behind the fascia of the instrument panel is limited, submodules 30a and 30b may be designed and delivered as separate units with push-button submodule 30a mounted a previously described in opening 10a of the instrument panel or center console and logic submodule 30b mounted elsewhere in the general environment of the instrument panel and connected to push-button submodule 30a in known manner by suitable wiring. For example, as seen in FIG. 14, push-button submodule 30a may be mounted in instrument panel opening 10a and logic submodule 30b may be mounted in the general area behind and below the facia of the instrument panel 10 with the submodules interconnected by wiring seen generally at 145.
FIG. 15 illustrates a schematic block diagram of the electrical control system of the present invention. This block diagram includes present gear encoder 210, speed analog-to-digital converter 212, desired gear encoder 214, lamp decoder/driver 216, indicator lamps 218, logic control unit 220 and motor driver circuit 222.
Present gear encoder 210 is connected to the lines 88 which are output of the encoder assembly 73, described above. Present gear encoder 210 includes one or more integrated circuits to encode the output signal from encoder assembly 73 into four signals PG1 to PG4. This encoding takes place, for example, in accordance with the coding table listed in Table 1.
TABLE 1______________________________________ PG1 PG2 PG3 PG4______________________________________Park 0 0 0 1-0Reverse 1 0 0 1-0Neutral 1 1 0 1-0Overdrive 0 1 0 1-0Drive 0 1 1 1-0Low1 1 1 1 1-0Low2 1 0 1 1-0______________________________________
Each unique combination of signals PG1, PG2 and PG3 indicates the angular range for a corresponding gear. FIG. 20 illustrates a roostertail control member 224 of known form connected to tubular shaft 27 and positioned within the transmission housing. As seen in FIG. 20, the signal PG4 is used to indicate the exact center of any particular gear range as represented by positioning of the usual spring loaded follower 226 in the precise dead center of the valley of the roostertail corresponding to the particular gear being selected. The encoder assembly 73 causes signal PG4 to change from "1" to "0" when the exact center of the angular range of the selected gear is reached. When this transistion in PG4 is detected, then the signals PG1, PG2 and PG3 are latched into the logic. This encoding technique ensures the mode select lever 22 is precisely positioned when the DC electric motor 42 is stopped. As a consequence the tramission is reliably positioned in the desired gear at the bottom of the valley of the roostertail corresponding to the desired gear. For example, as seen in FIG. 20, when R is selected by the vehicle operator, the described encoding technique ensures that the follower 226 comes to rest at the angular position 228 corresponding to bottom dead center of the roostertail valley corresponding to the reverse gear mode of the transmission.
Speed analog-to-digital converter 212 receives an analog signal indicative of speed on line 125. Speed analog-to-digital converter 212 generates an output signal on one or more of the output lines MPH3, MPH7, MPH20 and MPH30, depending upon the magnitude of the analog speed signal.
FIG. 16 illustrates in schematic form the preferred construction of speed analog-to-digital converter 212. In accordance with the preferred embodiment the speed signal comes from an existing sensor on the vehicle which generates an oscillating signal having a frequency proportional to the vehicle speed. The speed signal is applied to a frequency-to-voltage converter 230 and then to the positive input of each of a set of comparators 252, 254, 256 and 258. A voltage divider circuit 240 comprising resistors 241, 243, 245, 247 and 249 is connected between the positive supply voltage and ground. The node between resistors 241 and 243 is connected to the negative input of comparator 252; the node between resistors 243 and 245 is connected to the negative input of comparator 254; the node between resistors 245 and 247 is connected to the negative input of comparator 254; and the node between resistors 247 and 249 is connected to the negative input of comparator 258. Each of these comparator circuits 252 to 258 receives a reference voltage for comparison to the output from frequency-to-voltage converter 230. If the output from frequency-to-voltage converter 230 is greater than the reference voltage applied to comparator 252, this indicates a vehicle speed of greater than 30 miles per hour. Accordingly, the output of comparator 252 is the MPH30 signal. Similarly, comparator 254 generates a signal at output MPH20 when the voltage at the output of frequency-to-voltage converter 230 indicates a vehicle speed of greater than 20 miles an hour. Comparator 256 generates an output MPH7 when the input indicates a vehicle speed of greater than seven miles per hour. Lastly, comparator 258 generates an output MPH3 when the speed input signal indicates a vehicle speed of greater than three miles per hour. Each of these four digital speed signals are supplied to logic control unit 220, to be used in a manner which will be further disclosed below.
Desired gear encoder 214 is coupled to the plurality of push-buttons 100 employed to select the desired gear. Desired gear encoder 214 includes one or more integrated circuits which encode the last actuated switch 100 into a three-bit signal on lines SG1 to SG3. This encoding takes place, for example, in accordance with the coding table listed at Table 2.
TABLE 2______________________________________ SG1 SG2 SG3______________________________________Park 1 1 1Reverse 1 1 0Neutral 1 0 1Overdrive 1 0 0Drive 0 1 1Low1 0 1 0Low2 0 0 1______________________________________
A bus of these three lines SG1 to SG2 is supplied from desired gear encoder 214 to logic control unit 220. This bus indicates to logic control unit 220 the desired transmission state selected by the operator.
Lamp decoder/driver 216 receives the encoded present gear signal on the bus including the lines PG1 to PG4. Lamp decoder/driver 216 generates a signal to illuminate a single light of indicator lamps 218. In accordance with the preferred embodiment of the present invention each of the lamps of indicator lamps 218 is associated with one of the push-button switches 100. In particular, it is desirable that push-buttons 100 comprise lighted push-button switches with the indicator lamps enclosed therein. The individual indicator lamps are preferably connected to the illumination supply in a manner that enables the intensity of these lamps to be adjusted in accordance with the adjustment of the intensity of the interior instruments.
FIG. 17 illustrates circuit 260 of a typical indicator lamp 267. In this illustration indicator lamp 267 is a light emitting diode. A resistor 261 is connected to lamp decoder/driver 216 for supplying a bias current to the base of transistor 263. When transistor 263 is turned on lamp 267 shines with a first brightness. When transistor 263 is turned off resistor 265 carries the current through lamp 267, so that lamp 267 is illuminated with a second, lower intensity. The voltage supplied to lamp 267 comes from power supply 270. The interior lamp supply is applied to a voltage divider including potentiometer 275, and resistors 276 and 277. The voltage appearing at the node between resistors 276 and 277 depends upon the setting of potentiometer 275. This voltage supplies a base current to transistor 272 which is connected in an emitter follower circuit. The emitter current from transistor 272 flows through the selected lamp and through resistor 271. Diode 273 provides reverse voltage protection for transistor 272. Zener diode 274 supplies over voltage protection for transistor 272. In accordance with the preferred embodiment, adjustment of the instrument intensity via potentiometer 275 adjusts the intensity of the illunination of the indicator lamps 218.
Additional switches are connected to logic control unit 220. These include door switch 130, which indicates the open/closed status of the driver's door, seat switch 132 indicating whether or not the driver's seat is occupied, ignition switch 134 indicating the status of the ignition switch, accelerator switch 138 which indicates the full depression of accelerator pedal 138 and override switch 143. Brake switch 133 indicates the depression of the brake pedal and seat belt switch 135 indicates the closure of the driver's seat belt. Logic control unit 220 receives the above described input signals and generates three output signals. These include the clockwise motor drive signal and the counter-clockwise motor drive signal which are connected to motor driver circuit 220. In addition a down shift signal 92 is connected to solenoid 36 for effecting the down shifting of the transmission via kick-down lever 24.
In use various input signals, such as described above and illustrated in FIGS. 9 and 15, are supplied to logic control unit 220. Logic control unit 220 is configured to receive these input signals and generate the necessary drive signals to motor 42 and solenoid 36 for providing the selection of the desired gear. Logic control unit 220 could be constructed of a programmed microprocessor circuit. It is believed preferable to construct logic control unit 220 in hardware logic in a programmable logic array or a gate array. Hardware logic is believed preferable to a programmed microprocessor because there is no software to maintain, the development of the logic circuit is easier and the cost is lower. The following description of the action of logic control units 220 is made in relation to Boolean equations which can be embodied in the logic circuits of a programmable logic array or gate array. Those skilled in the art would understand that it is equally possible to perform the same Boolean operations with a programmable microprocessor circuit.
The operation of logic control unit 220 will now be described. Firstly, the various input signals are formed into a set of logic signals. The signals SG1 to SG3 are decoded into a set of signals whose state is selected by the depressed push-button 100; PARK, RVRS, NTRL, OVDR, DRVE, LOW1 and LOW2. One of these signals, corresponding to the desired gear selected by the depressed push-button, is a logic "1" while the other of these signals are a logic "0". Similarly the encoder signals PG1 to PG4 permit generation of a set of logic signals PGP, PG4, PGN, PGO, PGD, PGL1 and PGL2, one of which is active to indicate the present gear and the others of of which are inactive. This encoding and decoding technique is employed to reduce the number of lines required between the various circuits and to reduce the number of input lines to be connected to logic control unit 220. Logic control unit 220 receives the speed logic signals MPH3, MPH7, MPH20 and MPH30 from speed analog-to-digital converter 212. Logic control unit 220 forms signals from the additional inputs including DOOR indicating the opened/closed status of the driver's door via door switch 130, SEAT indicating whether or not the driver's seat is occupied via seat switch 132, IGN indicating the status of the ignition switch, ACC indicating whether or not the accelerator switch 138 is closed, OVRD indicating override via switch 143, BRAKE indicating depression of the brake pedal via switch 133 and SBELT indicating the closure of the driver's seat belt via switch 135.
Logic control unit 220 serves to compare the inputs indicating the desired gear with the inputs indicating the present gear. If they differ, then logic control unit 220 generates an output signal to motor 42 to rotate the motor until the present gear matches the desired gear. This process includes an indication of which shifts are upshifts (counter-clockwise motor rotation) and which are down shifts (clockwise motor rotation) according to the following Boolean equations: ##EQU1## Thus an up shift is required if the present gear is low1 (UP1), or the present gear if low2 and low1 is not requested (UP2), or the present gear is drive and neither low1 nor low2 are requested (UP3), or the present gear is overdrive and either neutral, reverse or park is selected (UP4), or the present gear is neutral and either reverse or park is selected (UP5), or the present gear is reverse and park is selected. A down shift is requested if none of the intermediate states are satisfied, that is the inverse of UPSHFT.
Two motor control signals CCW and CW are generated when the signals ENABLE and OK2SHFT are active and the respective UPSHFT or DNSHFT is active and shown below. ##EQU2## The ENABLE signal generally requires the desired gear to differ from the present gear and certain safety conditions to be satisfied. As shown below, ENABLE is inactive when the desired gear is the same as the present gear. ##EQU3## These intermediate signals are formed as follows: ##EQU4## Thus the logic control unit 220 does not permit a shift into low1 when the speed is in excess of 30 miles per hour, and likewise does not permit a shift to low2 if in excess of 20 miles per hour, to reverse if in excess of 7 miles per hour, or to park if in excess of 3 miles per hour. The second term in GOPARK automatically shifts to park if the ignition is switched off (Not(IGN)), or if the door is opened (Not(DOOR)) and the seat is empty (Not(SEAT)), the present gear is not park (Not(PGP)), the speed is not greater than 3 miles per hour (Not(MPH3)), and neutral override is not selected (Not(OVRD)).
The signal OK2SHFT is a safety lockout signal. It is formed as follows: ##EQU5## Thus OK2SHFT permits shifts if the ignition switch is enabled and the driver's seat is occupied, or if a gear is selected and the override switch 143 is activated. In either event shifts are not permitted if the transmission is currently in reverse gear and the vehicle speed is above 7 miles per hour. If desired OK2SHFT may also require connection of the driver's seat belt to enable any shift via the SBELT signal. Also, it may be desired to require depression of the brake to leave PARK gear by adding a term Not(PGP and Not (BRAKE)) to the equation for OK2SHFT.
The clockwise motor drive signal CW and the counter-clockwise motor drive signal CCW are generated by logic control unit 220 in accordance with the above Boolean equations. These signals are then conditioned via a one shot circuit before being applied to motor driver circuit 222. These one shot circuits are illustrated in FIG. 18. The counter-clockwise motor drive signal CCW is applied to the trigger input of one shot circuit 280 and one input of gate 282. Upon generation of this counter-clockwise motor drive signal CCW the state of one shot 280 is toggled to enable gate 282. At the same time, the output of NAND gate 282 is applied to the reset input of one shot 290, insuring that NAND gate 292 is cut off and the clockwise motor drive signal CW is inhibited. This signal is inverted via gate 284 and then applied to the motor driver circuit 222 in the manner illustrated in FIG. 15. When a predetermined period of time has elapsed one shot 280 reverses state. This serves to disable NAND gate 282 and stop the generation of the counter-clockwise motor drive signal CCW. This also removes the input to reset one shot 290, thereby permitting later generation of the clockwise motor drive signal CW. The length of time of one shot circuit 280 is set to be longer than the longest time for ordinary shifting. Thus if this time is exceeded some error condition has resulted and it is best to remove the motor drive from motor 42. A similar one shot circuit 290 operates on the clockwise motor drive signal CW utilizing NAND gate 292 and 294. The output of NAND gate 292 is also applied to the reset input of one shot 280 insuring that NAND gate 282 is cut off when the clockwise motor drive signal CW is generated. This prevents simultaneous generation of the clockwise motor drive signal CW and the counter clockwise motor drive signal CCW.
A pair of switches enable the transmission to be shifted manually. Auto/Manual switch 144 switches between the signals generated by logic control unit 220 and jog switch 147. In normal use auto/manual switch 144 is in the auto position illustrated in FIG. 15 in which the clockwise motor control signal CW and the counter clockwise motor control signal CCW generated by logic control unit 220 are coupled to motor driver circuit 222. In this position logic control unit 220 controls motor driver circuit 222 in accordance with the principles of the present invention explained herein. When auto/manual switch 144 is in the manual position, signals from jog switch 147 are coupled to motor driver circuit 222.
This jog switch 147 is preferably a double pole double throw momentary contact switch with a center off position. Momentary of jog switch 147 in one direction causes generation of the counter-clockwise motor drive signal CW, in the same manner as generated by logic control unit 220. Similarly, momentary actuation of jog switch 147 in the opposite direction generates the counter-clockwise motor drive signal CCW. These signals are applied to motor driver circuit 122 in the manner similar to the signals received from logic control unit 220. Jog switch 147 thus permits the user of the motor vehicle to change the state of the automatic transmission in the event of some failure of the electrical control system.
Motor driver circuit 222 is illustrated in detail in FIG. 19. The counter-clockwise motor drive signal CCW is applied to inverter 301. The output of inverter 301 is applied to switch 302 and to inverter 303. The output of buffer 303 is applied to switch 304. In a similar manner the clockwise motor control signal CW is applied to the input of inverter 305. The output of inverter 305 is applied to switch device 306. The output of inverter 305 is also applied to the input of inverter 307, which supplies the input to switch device 308.
Motor 42 is connected in an H bridge circuit between switch devices 302, 304, 306 and 308. Both clockwise motor drive signal CW and counter-clockwise motor drive signal CCW are normally inactive at a low voltage. Thus the output of inverter 301 is high and switch device 302 is conductive and switch device 304 is not conductive. Similarly, switch device 306 is normally conductive and switch device 308 is normally not conductive. Thus both terminals of motor 42 are connected to ground.
Upon receipt of an active counter-clockwise motor drive signal CCW inverter 301 switches states. Thus switch device 304 is turned on and switch device 302 is turned off. Because switch device 306 remains on, a current flows through motor 42 in a first direction through switch devices 304 and 306. When the desired shift position is reached, counter-clockwise motion drive signal CCW returns to the inactive low state. Thus switch device 302 is turned on and switch device 304 is turned off. Dynamic braking is achieved because both terminals of motor 42 are connected to ground (note switch device 306 has remained conductive during this sequence).
When clockwise motor drive signal CW is active, switch device 306 is turned off and switch device 308 is turned on. This causes a current to flow through motor 42 in the opposite direction through switch device 308 and switch device 302. Likewise when the clockwise motor drive signal CW ceases motor 42 is dynamically braked by both terminals being connected to ground.
Thus motor 42 is controlled to rotate clockwise or counter-clockwise in accordance with the signal supplied from logic control unit 220. Motor control circuit 222 illustrated in FIG. 19 also includes a feature for dynamically breaking motor 42 when neither the counter-clockwise motor control signal CCW nor the clockwise motor control signal CW is generated.
As soon as the instantaneous encoder signal transmitted by pick-up device 76 matches the signal generated by the specific depressed push button, logic control unit 220 of control module 10 functions to deenergize and brake the motor so that the mode select lever 22, and thereby the transmission, is stopped precisely in the selected shift position. If the lever 60 construction of FIG. 13 is employed, springs 64,65 coact with piston 60i to ensure that the internal detent controlled by lever 22 does not hang up on a crest of the known roostertail in the transmission but that, rather, the detent is moved to a precise shift position in which it is firmly seated in a notch or valley of the roostertail.
If at any time the operator desires to downshift the transmission as, for example, in a passing situation, the accelerator pedal 14 is fully depressed to close switch 138. A signal from the closed switch 138 is transmitted to logic control unit 220 by lead 126 where it is amplified by a buffer device 142 carried by printed circuit 104 and transmitted in amplified form through lead 92 to solenoid 36 which is thereby energized to retract the plunger of the solenoid and pivot downshift lever 24 in a counter-clockwise direction, as viewed in FIG. 9, to effect the desired downshifting of the transmission.
As previously described, the invention system would also preferably include illumination means for the push buttons 100 with the intensity of the illumination controlled by the usual dash dimmer and with the button corresponding to the present gear being illuminated brighter than the remaining buttons to provide a ready indication of the instantaneous position of the transmission. An override push button 143 is also provided as a part of push button submodule 30a. Override push button 143 allows the selection of any gear when it is necessary for the seat to be empty and the vehicle to be in a gear other than PARK, for example, during vehicle tune-up, vehicle car wash, et cetera.
An alternate form of encoder assembly is shown in FIGS. 10-12. In this arrangement, the encoder assembly, rather than being provided within the sealed cavity 78 of the speed reduction unit 44, is provided as an independent unit 146 adapted to be fitted over the mode select lever 11 and to move with that lever so as to constantly sense the position of that lever and thereby sense the shift position of the transmission.
Encoder assembly 146 includes a housing 148, an encoder member 150, and a pick-up device 152.
Housing 148 may be formed of any suitable rigid material and includes an outer wall 148a, an inner wall 148b, flange portions 148c, an aperture 148d in outer wall 148a, an aperture 148e in inner wall 148b, and an arcuate slot 148f in inner wall 148b. In this embodiment, the central shaft 26 on which the kick-down lever 24 is mounted is extended to provide a shank portion 26a, shoulder portion 26b, and a threaded end portion 26c.
Encoder member 150 is arcuate and includes coded indicia 154 provided on tracks 154a, 154b, 154c and 154d generally corresponding to tracks 80a, 80b, 80c and 80d on encoder wheel 74. Pins 156 project from the face of encoder member 150 opposite the face on which indicia 154 is provided.
Pick-up device 152 includes a body portion 158 and resilient fingers 160 for coaction with the coded indicia on encoder member 150.
Encoder member 150 is positioned within the hollow interior 162 of housing 148 with pins 156 passing sealingly through arcuate slot 148f, and pick-up device 152 is positioned on the inner face of outer housing wall 148a with fingers 160 is coacting relation to the coded indicia on encoder member 150.
Encoder assembly 146 is fitted over shaft 26 with housing aperture 148e positioned on shank portion 26a, aperture 150a of encoder member 150 positioned on shank 26a, outer wall 148a positioned on shoulder 26b, and a nut 4 engaging threaded end portion 26c and seating against the annular shoulder between shaft portions 26b and 26c so as to preclude axial displacement of encoder assembly 146 relative to shaft 26 but allow rotation of the shaft relative to encoder assembly 146. Rotation of the encoder assembly is prevented by engagement of flange portions 148c with suitable portions on the transmission housing with kick down lever 24 disposed between spaced flanged portions 148c and pivotal in the space provided between the flange portions. Pins 156 snugly engage the opposite side edges of mode select lever 22 so that encoder member 150 moves positively and precisely in accordance with the movement of the mode select lever and so that the encoder signal picked up, generated and transmitted by pick-up device 152 from the coded indicia on encoder member 150 is always representative of the precise shift position of the transmission.
The invention electric control system for an automatic transmission apparatus will be seen to have many advantages. Specifically, the two modular assemblies minimize components and inventory requirements; the ease of assembly of the modules minimizes assembly plant labor; the power and control modules may both be pretested prior to delivery to the vehicle manufacturer with consequent improvements in reliability and warranty costs; noise and vibration from the power train to the passenger compartment is substantially minimized; the awkward and intruding gear select lever is eliminated in favor of attractive flush-mounted push buttons in the instrument panel of the vehicle; and several important safety and convenience features are provided such as automatic shifting to park when the ignition is shut off; automatic prohibition of shifts that would be inappropriate in view of the sensed vehicle speed and direction, and automatic movement of the transmission to park in the event that the driver opens the door and leaves the seat with the engine running and the transmission in a position other than park. The invention electric shift apparatus thus provides many comfort, convenience, and safety advantages as compared to existing transmission control systems and yet may be provided at a cost that is competitive with the existing systems and with projected maintenance and warranty costs less than the existing systems.
Whereas preferred embodiments of the invention have been illustrated and described in detail it will be apparent that various changes have been made in the disclosed embodiments not departing from the scope or spirit of the invention. It should be particularly noted that various of the electronic circuits, such as present gear encoder 210, desired gear encoder 214 and lamp decoder/driver 216, could be embodied in the same integrated circuit as logic control unit 220.
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The present invention is an electrical control apparatus for control of an automatic transmission in a motor vehicle. The automatic transmission has a motor for controlling the transmission state. The electrical control apparatus includes an operator input device, preferably a set of push buttons, for generating a desired transmission state signal, a transmission state sensing device for generating a present transmission state signal, and a logic control unit for control of the transmission motor. If the desired transmission state differs from the present transmission state, then the logic control unit generates either a clockwise motor drive signal or a counter-clockwise motor drive signal as needed to reach the desired transmission state. A motor drive circuit controls the motor for motion corresponding to the received drive signal. The control logic unit preferably also includes logic for inhibiting the generation of the clockwise and counter-clockwise motor control signals upon detection of an unsafe circumstance which would make a particular shift hazardous or harmful to the vehicle.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to electrical condensate overflow safety switches and, more particularly, to a float actuated magnetic reed switch attachable to the condensate drainage system of an air-cooling system for deactivating the system upon the level of condensate in the condensate drainage system reaching a predetermined level, thereby preventing collected liquid condensate from overflowing the condensate drainage system.
[0003] 2. Discussion of the Related Art
[0004] Most residential and commercial air-conditioning and refrigeration units employ an evaporator coil to dehumidify and cool ambient air in dwellings, climate controlled storage spaces, work spaces, and the like. The evaporator coil is frequently located indoors, often above the occupied areas of the building that it serves. Since the coil is colder than the air being conditioned, it condenses water liquid while in operation. This condensate liquid is typically collected in a drain pan, usually positioned under the coil, with the drain pan having one or more outlet ports for attaching a drain pipe for outflow of the condensate. Many units have a secondary drain pan which may not have any outlets or connecting drain pipes. During normal operation, the condensate water liquid drains through one or more of the outlets of the main drain pan, through a drain pipe and out from the building. However, the drain pan, pan outlets and drain pipe, often become occluded by algae, mold, mildew, dirt and other accumulated debris. An occlusion in the outlets and/or drain pipes will eventually result in drain pan overflows that can cause water damage to building ceilings, walls, flooring, and associated building components, which necessitate costly repairs. In units which use a secondary drain pan, the liquid condensate will first overflow into the secondary drain pan. In some instances, the secondary drain pan will overflow and cause water damage.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to an overflow safety switch for attachment to the condensate drainage system of an air-cooling system in order to prevent overflow of condensate which collects in the condensate drainage system. In accordance with various embodiments of the invention, the overflow safety switch may be attached to one of the vertical side walls of the drain pan or through the bottom of the drain pan or drain pipe. In one embodiment, a brace attaches to the side wall of the drain pan and holds the overflow safety switch in a vertical upright position within the drain pan. In another embodiment, the overflow safety switch is mounted through the side wall and maintained in a generally horizontal position. In yet another embodiment, the overflow safety switch is mounted through the bottom of the drain pan so that the safety switch is held vertically upright within the drain pan. In still a further embodiment, the overflow safety switch is connected to a drain pipe or drain outlet extending from the drain pan.
[0006] In each embodiment, the overflow safety switch is electrically connected to either a circuit of the air-cooling system, a power circuit or an alarm circuit. The overflow safety switch includes a tube which extends within any water conducting area of condensate drainage system. A reed switch is sealed within the tube and a float containing a magnet is moveably supported on the exterior of the tube. The float ascends or descends in response to the level of the liquid condensate within the condensate drainage system. As the float moves relative to the tube, the magnet causes the reed switch to open or close, thereby interrupting operation of the air-cooling system and/or actuating the alarm circuit. In yet a further embodiment, a normally open reed switch is connected to an alarm circuit, wherein movement of the float and magnet, in response to a rise in liquid in the drain pan, results in closing of the switch and activation of the alarm circuit.
OBJECTS AND ADVANTAGES OF THE INVENTION
[0007] With the forgoing in mind, it is a primary object of the present invention to provide a condensate overflow safety switch for quick and easy attachment to the condensate drainage system of an air-cooling system, and wherein the overflow safety switch is structured and disposed to interrupt operation of the air-cooling system and/or activate an alarm upon the condensate liquid reaching a predetermined level at any point in the condensate drainage system, thereby preventing the condensate from overflowing the drain pan.
[0008] It is a further object of the present invention to provide an overflow safety switch characterized by simple mechanical and electrical design, compactness, non-corrosive, low manufacturing complexity, water sealed design and high operational reliability.
[0009] It is still a further object of the present invention to provide a condensate overflow safety switch which is structured and disposed for easy and quick attachment to the condensate drainage system of an air-cooling system, and wherein the overflow safety switch is structured and disposed to stop generation of condensate liquid in the event of a drain system occlusion, thereby preventing collected condensate liquid from overflowing the condensate drainage system which might otherwise result in property damage.
[0010] These and other objects and advantages of the present invention are more readily apparent with referenced to the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a fuller understanding of the nature of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:
[0012] FIG. 1 is a top perspective view of a condensate overflow safety switch and mounting bracket for attaching the safety switch to the side wall of a drain pan in an air-cooling system, in accordance with one preferred embodiment of the present invention;
[0013] FIG. 2 is a cross-sectional view taken from the line indicated as 2 - 2 in FIG. 1 ;
[0014] FIG. 3 is a perspective view, shown in cutaway, illustrating a condensate overflow safety switch mounted through the side wall of a drain pan in an air-cooling system, in accordance with a second preferred embodiment of the present invention;
[0015] FIG. 4 is a cross-sectional view taken along the line indicated as 4 - 4 in FIG. 3 ;
[0016] FIGS. 5 and 6 are side elevation views, shown in partial cross-section, showing the overflow safety switch of FIG. 1 mounted to the side wall of a drain pan and illustrating a sequence of operation of the overflow safety switch between a low condensate level condition, wherein the overflow safety switch is in an normally closed circuit condition, and a raised condensate liquid level, wherein the overflow safety switch is in an open circuit condition to deactivate the air-cooling system;
[0017] FIGS. 7 and 8 are side elevational views, shown in partial cross-section, showing the overflow safety switch of FIG. 3 mounted to the side wall of a drain pan and illustrating a sequence of operation of the overflow safety switch between a low condensate level condition, wherein the overflow safety switch is in a normally closed circuit condition, and a raised condensate liquid level, wherein the overflow safety switch is in an open circuit condition to deactivate the air-cooling system;
[0018] FIGS. 9 and 10 are side elevational views, shown in partial cross-section, showing the overflow safety switch mounted through the bottom of the drain pan, in accordance with yet another embodiment of the invention, and illustrating a sequence of operation of the overflow safety switch between a low condensate level condition, wherein the overflow safety switch is in a normally closed circuit condition, and a raised condensate liquid level, wherein the overflow safety switch is in an open circuit condition to deactivate the air-cooling system; and
[0019] FIGS. 11 and 12 are side elevational views, shown in partial cross-section, showing the overflow safety switch mounted within a drain pipe leading from the drain pan of a condensate drainage system and illustrating a sequence of operation of the overflow safety switch between a low condensate level condition, wherein the overflow safety switch is in a normally closed circuit condition, and a raised condensate liquid level, wherein the overflow safety switch is an open circuit condition to deactivate the air cooling system.
[0020] Like reference numerals refer to like parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] In each of the preferred embodiments, as shown throughout the drawings, the overflow safety switch assembly is generally indicated as 10 and includes a hollow tube 12 having an open end portion 14 and a closed end portion 16 with an outer surface 18 extending therebetween. A reed switch 20 has overlapping electrical contacts 22 connected to insulated wires 30 . The contacts 22 of the reed switch 20 and the exposed ends of the wires 30 are maintained within the hollow tube 12 . A sealing material 32 , for example plastic or epoxy, insulates the reed switch 20 and exposed ends of the wires 30 within the hollow tube 12 , thereby preventing contact with moisture. A portion of the outer surface 18 may be provided with threads 28 to facilitate attachment of the switch assembly to either a mounting clip 60 , as shown in FIGS. 1 and 2 , or directly to the drain pan 100 of an air-cooling system, as seen in FIGS. 3-4 and 7 - 10 . The threads 28 on the outer surface 18 of the hollow tube serve to permit adjustable positioning of the hollow tube relative to the drain pan 100 , as described more fully hereinafter. The overflow safety switch assembly may also be connected in-line to the drain pipe extending from the drain pan.
[0022] Referring now to the embodiment shown in FIGS. 1-2 and 5 - 6 , the overflow switch assembly 10 is provided with a float body 40 having a first end face 42 and a second end face 44 . A removable stopper mechanism 38 , such as a C-clip, is engaged onto the outer surface 28 of the hollow tube 12 , adjacent the closed end portion 16 . The float body 40 ′ is captivated on the hollow tube 12 , between the end portions 14 , 16 and is slidably moveable between the stopper mechanism 38 and an upper shoulder 48 defined by a fixed hex nut configuration integrally formed or adjustably moveable on the hollow tube. The float body 40 is moveable between a lowered position, as seen in FIGS. 2 and 5 , and a raised position, as seen in FIG. 6 , in response to a raising condensate liquid level within the drain pan. The float body 40 is provided with a magnet 50 which may be exposed on the inner diameter of the float body. The magnet 50 is positioned in confronting relation to the outer surface 18 of the hollow tube and is disposed closer to the first end face 42 then the second end face 44 of the float body 40 . When the wires of the reed switch are connected to a circuit of the air-cooling system, the float body 40 is mounted with the first end face 42 facing toward the stopper mechanism 38 near the end portion 16 . When the wires are connected to an alarm circuit, the float body is mounted with the second end face 44 facing toward the stopper mechanism 38 . In the embodiment shown in FIGS. 1-2 and 5 - 6 , the wires are connected to the circuit of the air-cooling system. In this instance, the contact elements 22 of the reed switch 20 are normally closed, maintaining a closed circuit condition, with the float body 40 at the lowered position, as seen in FIGS. 2 and 5 . As the condensate liquid fluid level rises within the drain pan 100 , the float body 40 moves upwardly along the hollow tube 12 . Eventually, the magnet 50 is moved into position to cause the contact elements 22 of the reed switch 20 to separate, as shown by the float body position in FIG. 6 , thereby opening the circuit and disabling the air-cooling system. Accordingly, when the condensate fluid level reaches a predetermined height in the drain pan 100 , as seen in FIG. 6 , the reed switch 20 is opened to disable the air-cooling system and prevent further production of condensate liquid until the occlusion, blockage or other drainage problem is fixed.
[0023] As seen in FIGS. 1-2 and 5 - 6 , the overflow switch assembly 10 is supported vertically in the drain pan 100 so that the lower closed end portion 16 extends downwardly within the drain pan, with the closed end positioned in close spaced relation to the bottom surface of the drain pan. A clip 60 is used in this particular embodiment for supporting the overflow switch assembly 10 in this position. In a preferred embodiment, the clip 60 is formed from a single piece of material, such as a metal alloy, and includes a horizontal plate 62 , a vertical plate 64 and an inverted U-shaped portion 66 between the horizontal and vertical plates. The inverted U-shaped portion 66 is specifically structured and disposed to slip easily over the top edge of the drain pan and hold securely, as seen in FIGS. 5 and 6 . Tabs 68 are provided on the vertical plate for frictional engagement against the outer surface of the drain pan side wall, thereby holding the clip 60 in place on the drain pan 100 . A screw 70 may be used for tightly securing the clip 60 onto the drain pan. Once the clip is attached to the drain pan, the position of the overflow switch assembly relative to the bottom of the drain pan may be adjusted by threadably advancing the hollow tube 12 relative to the horizontal plate 62 of the clip 60 . To this end, it should be noted that, in a preferred embodiment, a through hole is formed through the horizontal plate 62 of the clip and is specifically sized and configured for threadable engagement with the exterior threads 28 on the outer surface 18 of the tube 12 .
[0024] Referring to the embodiment shown in FIGS. 3-4 and 7 - 8 , a float body. 40 ′ is supported on the hollow tube 12 between the stopper mechanism 38 on the closed end portion 16 and the shoulder 48 . In this particular embodiment, the hollow tube 12 is mounted horizontally through the side wall of the drain pan 100 and the annular float body 40 ′ is provided with an elongate rectangular passage 41 extending between the first end face 42 ′ and the opposite second end face 44 ′. A magnet 50 ′ is embedded within a lower portion of the float body and is normally spaced from the outer surface 18 of the hollow tube, as seen in FIG. 4 , a sufficient distance so that there is no magnetic influence exerted on the elements 22 on the reed switch 20 within the hollow tube 12 . As the condensate liquid level rises within a drain pan 100 , the float 40 ′ naturally rises relative to the hollow tube 12 , eventually reaching the position shown in FIG. 8 . At this position, the magnet 50 ′within the lower portion of the float body 40 ′ is moved close to the outer surface 18 of the hollow tube 12 , resulting in a magnetic attraction between the magnet 50 ′and reed switch 20 , and causing the elements 22 of the reed switch to separate, thereby opening the circuit and disabling the air-cooling system. As seen in FIG. 4 , a rubber O-ring seal 80 or washer is fitted about the outer surface 18 , at the threaded portion 28 of the hollow tube, and is placed against the outer surface of the side wall of the drain pan 100 , surrounding a through hole drilled through the drain pan. This seal 80 is held tight against the outer surface of the drain pan with a nut 82 or other fastening device which further serves to secure the switch assembly 10 in the horizontal position and attached to the side wall of the drain pan. The seal 80 , when tightly sandwiched between the nut 82 and outer surface of the drain pan side wall prevents leakage through the hole in the side wall of the drain pan.
[0025] Referring to FIGS. 9 and 10 , a further embodiment of the overflow switch assembly 10 is shown. In this particular embodiment, the structure of the switch assembly 10 is similar to that shown in connection with the embodiment of FIGS. 1-2 . In the embodiment shown in FIG. 9 and 10 , the hollow tube 12 and the reed switch 20 are mounted upwardly through the bottom of the drain pan so that the closed end portion 16 is spaced sufficiently above the inner bottom surface of the drain pan. To secure the overflow safety switch 60 to the drain pan 100 , a hole may be drilled through the bottom of the drain pan. The hole may be sized and configured for threadable, advanced passage of the threaded end portion of the hollow tube. Once securing and adjusting the hollow tube 12 at the desired height within the drain pan, a seal 80 may be placed around the hole in the bottom of the drain pan through which the hollow tube extends. Similar to the embodiment of FIGS. 1-2 , the float 40 includes a magnet 50 which moves with the float body in relation to the outer surface 18 of the hollow tube 12 and the reed switch 20 therein. In the position shown in FIG. 9 , the annular float body 40 is in lowered position, due to a low condensate liquid level in the drain pan 100 . As the condensate liquid level rises, the annular float body 40 moves upwardly along the hollow tube 12 causing the magnet 50 within the float body to separate. This results in opening the circuit and disabling the air-cooling system so that no further condensation is produced until the blockage or other drainage problem is fixed.
[0026] Referring to FIGS. 11 and 12 , the overflow switch assembly 10 is shown in yet a further embodiment wherein the switch assembly 10 is fitted to a pipe 120 with the hollow tube 12 extending through the pipe so that the upper shoulder 48 , closed end portion 16 and float body 40 are positioned within the pipe. As seen in FIGS. 11 and 12 , the hollow tube 12 is fixed to the pipe 120 so that the outer surface 18 between the upper shoulder 48 and stopper mechanism 38 is vertically positioned, thereby permitting movement of the float body 40 between a lowered position and a raised position as the fluid liquid level in the pipe changes. FIG. 11 illustrates a normal condition, wherein fluid is flowing freely and unobstructed through the pipe 120 . In this instance, the fluid level remains low with the float body 40 at the lowered position, thereby maintaining the overflow safety switch in a normally closed circuit condition. In the event the liquid level rises within the pipe 120 , due to a clog or other obstruction, the float body 40 rises, as seen in FIG. 12 , to operate the overflow safety switch to the open circuit condition, thereby interrupting electric current flow through conductors 30 . The installation of the overflow safety switch in the manner shown in FIGS. 11 and 12 is particularly useful in drain pipes of an air cooling system. In this instance, the overflow safety switch 10 is fitted in-line to the drain pipe leading from a drain pan of the air cooling system's drain system. In the event of a down line clog or other obstruction in the drain pipe 120 , the liquid level will rise in the pipe, as shown in FIG. 12 . When the float body moves up to the raised position seen in FIG. 12 , the circuit is opened and the air cooling system is disabled so that no further condensation is produced until the blockage in the drain pipe is removed. Accordingly, in the event of a blockage or other drainage problem, the air cooling system will be disabled with little or no liquid accumulation in the drain pan.
[0027] While the instant invention has been shown and described in accordance with preferred and practical embodiments thereof, it is recognized that departures from the instant disclosure are contemplated within the spirit and scope of the present invention.
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A safety switch prevents overflow of condensate that collects in the drain pan of an air-cooling system. The overflow safety switch attaches to the condensate drainage system and is electrically connected to a circuit of the air-cooling system, a power circuit, a control circuit and/or an alarm circuit. The switch includes a tube that extends within the condensate drain pan or any other water conducting point in the condensate drainage system. A reed switch is sealed within the tube and a float containing a magnet is moveably supported on the exterior of the tube. The float ascends or descends in response to the level of the liquid condensate within the drain pan. As the float moves relative to the tube, the magnet causes the reed switch to open, thereby interrupting operation of the air-cooling system and/or actuating the alarm circuit.
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PRIORITY CLAIM TO PROVISIONAL APPLICATION
A claim for priority is hereby made under the provisions of 35 U.S.C. §119 for the present application based upon U.S. Provisional Patent Application Ser. No. 61/464,667 filed on Mar. 7, 2011 titled “UNDERWATER ACTIVATED SUBMERGED OBJECT RETRIEVAL DEVICE,” and U.S. Provisional Application Ser. No. 61/519,455 filed on May 23, 2011 titled “UNDERWATER ACTIVATED SUBMERGED OBJECT RETRIEVAL DEVICE,” and U.S. Provisional Application Ser. No. 61/626,396 filed on Sep. 26, 2011 titled “UNDERWATER ACTIVATED SUBMERGED OBJECT RETRIEVAL DEVICE,” all three of which are incorporated herein by reference in their entirety for all that is taught and disclosed therein.
FIELD OF INVENTION
The present Applicant relates generally to retrieval devices for objects utilized in and around fluidic media.
BACKGROUND
Nearly everyone has dropped an object into water or some other fluidic medium and been unable to retrieve the object for any number of reasons. Sportsmen, for example, may spend significant time in or around water when boating or fishing. As is often the case, a fishing pole or some accessory may be inadvertently dropped in the water. The first response to dropping an object is to lunge forward to grab the object before it falls out of sight. Lunging may not be particularly desirable as the tendency to slip and injury oneself may be significant. Another response may be to enter the water to retrieve the object. However, a lone boater may be unwilling to enter the water for any number of safety related reasons.
Over time, many devices have been developed to address this problem. Manufacturing issues, reliability issues, and size issues have all contributed to prevent development of an effective device for retrieving submerged objects. As such, fluid activated retrieval devices are presented herein.
SUMMARY
The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented below.
As such, fluid activated retrieval devices for retrieving an object from a fluidic medium are presented including: a hollow base having a cavity formed therein, where the hollow base includes, a port disposed along an outer surface of the hollow base, the port configured to provide passage of the fluidic medium to the cavity, a diaphragm disposed along the cavity and proximate to the port, the diaphragm configured to selectively allow the fluidic medium to enter the cavity, and an anchor disposed along the cavity for securing a line; a deployable float housing removably attached with the hollow base, the deployable float housing having another cavity formed therein, where the deployable float housing includes, a buoyant chamber disposed along a distal end of the other cavity, a spool for receiving the line, the spool disposed within the second cavity and attached with the deployable float housing; and a reactant disposed in the cavities, the reactant responsive to the fluidic medium such that when the reactant comes into contact with the fluidic medium a reactant gas is generated.
In some embodiments, the hollow base further includes: a mating portion for mating the hollow base with the deployable float housing, the mating portion disposed along one end of the hollow base, where the mating portion includes, a mating surface, a seal disposed circumferentially along the mating surface, the seal configured to provide a fluid-tight seal between the hollow base and the deployable float housing, and a raised annular feature disposed circumferentially along the mating surface. In some embodiments, the deployable float housing further includes an annular channel disposed circumferentially along the other cavity, where the annular channel is a recessed feature having a profile suitable for receiving the raised annular feature. In some embodiments, the profile includes a sloped portion disposed along an outer edge of the annular channel.
In some embodiments, the hollow base further includes: a port passage disposed orthogonally to the at least one port, the port passage extending from the port to the outer surface. In some embodiments, the diaphragm further includes: a shore hardness in a range of approximately 40 to 80 shore; and a thickness in a range of approximately 0.01 to 0.1 inches, where the diaphragm is configured to selectively allow the fluidic medium to enter the first cavity at a pressure in a range of approximately 2 to 100 pounds per square inch (PSI). In some embodiments, the diaphragm is a material such as: a semi-flexible elastomeric compound, a flexible elastomeric compound, a silicone compound, a VITON elastomeric compound, a neoprene compound, a rubber compound, and a rubberized compound.
In some embodiments, the hollow base further includes: a strap guide disposed along the outer surface for receiving an attaching strap; and legs disposed along the outer surface for raising the fluid activated retrieval assist device from an object surface. In some embodiments, the reactant includes a mixture such as: a citric acid/sodium bicarbonate mixture, a tartaric acid/sodium bicarbonate mixture, and an acetic acid/sodium bicarbonate mixture. In some embodiments, the reactant further includes an anti-agglomeration agent compatible with the reactant. In some embodiments, the reactant further includes a desiccating agent. In some embodiments, the fluidic medium includes: an aqueous medium, a petroleum based medium, and an organic solvent medium.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 is an illustrative representation of a fluid activated retrieval device in accordance with embodiments of the present invention;
FIG. 2 is in illustrative representation of a hollow base of a fluid activated retrieval device in accordance with embodiments of the present invention;
FIG. 3 illustrates representations of various fluid activated retrieval device configurations in accordance with embodiments of the present invention; and
FIG. 4 is an illustrative representation of deploying a fluid activated retrieval device in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
The present invention will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
FIG. 1 is an illustrative representation of a fluid activated retrieval device 100 in accordance with embodiments of the present invention. In particular, an exploded view 110 of fluid activated retrieval device 100 is illustrated for clarity in understanding embodiments disclosed herein. As illustrated, fluid activated retrieval device 100 includes several component parts or assemblies. Hollow base 112 may form a cavity into which several components may be housed including, for example, diaphragm 114 and anchor 116 . Hollow base configurations will be discussed in further detail below for FIG. 2 . As illustrated, diaphragm 114 may be sized to partially flex when installed in hollow base 112 . The flexion provided by diaphragm embodiments, when installed properly, may serve to selectively allow fluidic media to enter the hollow base cavity whereupon the fluidic media interacts with a reactant in the hollow base cavity to produce a reactant gas. The reactant gas, in turn, produces a pressure sufficient to deploy the fluid activated retrieval device. In embodiments, the reactant gas produces a deploying pressure of at least 2-40 PSI in excess of surrounding environment pressure. Deployment of fluid activated retrieval device embodiments will be discussed in further detail below for FIG. 4 .
In embodiments, the diaphragm operates to maintain equalization between the interior of fluid activated retrieval device embodiments and surrounding fluidic media thereby effectively functioning as a check valve. In embodiments, diaphragms may have a hardness in a range of approximately 40 to 80 shore. In some embodiments, diaphragms may include a thickness in a range of approximately 0.01 to 0.1 inches. In other embodiments, diaphragms may be configured to selectively allow fluidic media to enter the hollow base cavity at a pressure in a range of approximately 2 to 100 pounds per square inch (PSI). In operation, diaphragms may be configured to enable fluidic media to enter the hollow base cavity at approximately 2 to 10 PSI above the initial internal pressure of the hollow base cavity. In embodiments, the initial internal pressure of the hollow base cavity at sea level is approximately one atmosphere. In embodiments, diaphragms may be composed of materials such as: a semi-flexible elastomeric compound, a flexible elastomeric compound, a silicone compound, a VITON elastomeric compound, a neoprene compound, a rubber compound, and a rubberized compound without limitation.
Further illustrated is anchor 116 that may be housed in the hollow base cavity. Anchor 116 may be utilized to secure a line with hollow base 112 . In the embodiment shown, a press-fit star washer is illustrated. However, in other embodiments, a tab, a flange, or a perforated disc may be similarly utilized without limitations. In embodiments, lines may be secured to anchors or directly with hollow base cavity in any manner known in the art such as, for example: tying, welding, gluing and otherwise bonding. Further, in embodiments, lines may be composed of any material known in the art without limitation such as, for example: a polymeric material, a braided polymeric fiber, a nylon material, a KEVLAR material, a natural fiber, and a metal fiber. A suitable line may be selected based on any of several factors including type of fluidic medium, weight of object attached with fluid activated retrieval devices, and line length requirements.
Still further as illustrated, deployable float housing 120 may be removably attached with hollow base 112 and may form a cavity into which components may be housed including, for example, spool 122 . In embodiments, spool 122 may include winding stop 124 disposed along an end of spool 122 and sealing flange 126 disposed along spool 122 . Winding stops may be shaped to secure lines (not shown) before deployment and to easily unwind lines during deployment. Furthermore, in embodiments, sealing flanges may be arranged to seal buoyant chamber 130 from deployable float housing cavity 134 . In some embodiments, buoyant chambers are empty and rely solely on an enclosed cavity for buoyancy. In other embodiments, buoyant chambers include a buoyant material such as, for example, a closed-cell foam material, a polystyrene foam material, a STYROFOAM material, and a cork material. Still further, in some embodiments, deployable float housing 120 may include spool receiver 134 for receiving spool 122 . It may be appreciated that in some embodiments, spool 122 is not configured to “spin” in order to unwind a spooled line.
FIG. 2 is in illustrative representation of a hollow base 200 of a fluid activated retrieval device in accordance with embodiments of the present invention. In particular, several views are provided for clarity in understanding embodiments disclosed herein. As illustrated, hollow base 200 may include several features. For example, in embodiments, hollow base 200 may include one or more ports (not shown) configured to provide passage of fluidic media to the hollow base cavity. In some embodiments, one or more port passages 202 may be disposed orthogonally to the port (not shown) extending to the outer surface of hollow base 200 . In embodiments, port passages may improve resistance to clogging or fouling of ports.
Hollow base 200 may further include mating portion 204 for mating hollow base 200 with deployable float housings as provided herein. Mating portion 204 may include, in embodiments, a mating surface having a number of features. One feature illustrated is seal 208 disposed circumferentially along the mating surface in an annular channel. In embodiments, seal 208 is configured to provide a fluid-tight seal between hollow base 200 and deployable float housings. In embodiments, seals may be an O-ring configuration composed of a material suitably compatible with a selected fluidic medium. Thus, for example, in an aqueous solution, an O-ring resistant to aqueous solutions may be utilized without departing from embodiments disclosed herein. Likewise, in a petroleum solution an O-ring resistant to petroleum solutions may be utilized without departing from embodiments disclosed herein.
Another feature illustrated is raised annular feature 206 disposed circumferentially along the mating surface. Raised annular feature 206 may provide a “snap” connection with annular channel 220 a and 220 b disposed circumferentially along deployable float housing cavity—a portion of which is illustrated here. In embodiments, annular channel 220 a and 220 b include recessed features 212 a and 212 b respectively, each having a profile suitable for receiving the raised annular feature. As illustrated, recessed feature 212 a has a matching profile for receiving raised annular feature 206 . Further as illustrated, recessed feature 212 b has a partially sloped profile for receiving raised annular feature 206 . In this embodiment, the sloped portion of the feature may serve to “pull” raised annular feature 206 toward deployable float housing embodiments to provide an improved fitment.
Still another feature illustrated is sloped portion 210 . In embodiments, sloped portion 210 may provide a guiding feature during assembly such that hollow base embodiments may be readily mated with deployable float housings embodiments. Further as illustrated, hollow base 200 is circular in cross-section. However, any number of base cross-sections may be utilized without departing from embodiments herein such as, a semicircular cross-section, an ovate cross-section, a semi-ovate cross-section, a rectangular cross section, and a semi-rectangular cross-section. In like manner, deployable float housing embodiments may include any number of housing cross-sections such as, a circular cross-section, a semicircular cross-section, an ovate cross-section, a semi-ovate cross-section, a rectangular cross section, and a semi-rectangular cross-section each selected to match base cross-sections.
In addition to mating portion 204 , hollow base 200 further includes a number of legs 230 . In embodiments, legs may be useful for raising fluid activated retrieval devices from an object surface to improve deployment. In some embodiments, legs may provide longitudinal alignment when, for example, fluid activated retrieval devices are mounted on a curved surface such as a fishing pole or canister. Thus, leg embodiments may include a shape suitable for mounting with any number of objects or surfaces without departing from embodiments herein. In some embodiments, legs may further include pads, coatings, tabs, holes, or any number of structures suitable for improving object mounting. Further illustrated is strap guide 232 disposed along the outer surface of the hollow base for receiving an attaching strap or tie. Other attaching configurations will be discussed in further detail below for FIG. 3 .
FIG. 3 illustrates representations of various fluid activated retrieval device configurations in accordance with embodiments of the present invention. In particular, FIG. 3 illustrates side views of several embodiments utilizing structures for receiving straps, ties, wire, rope, belts, or clamps to secure fluid activated retrieval devices to various objects. It may be appreciated that the figures illustrated are exemplary only and not intended to be limiting as fluid activated retrieval devices may be mounted to objects in any number of ways known in the art without departing from embodiments provided herein: that is with or without strap guides. For example, in embodiments not shown, fluid activated retrieval devices may be bonded, glued, bolted, riveted, screwed, or welded to an object without limitation. As illustrated, fluid activated retrieval device 300 includes strap guide 302 that may be integrated with leg 304 for receiving a securing element such as straps, ties, wire, rope, belts, or clamps. Further as illustrated fluid activated retrieval device 310 includes two or more strap guides 312 that may be integrated with leg 314 for receiving a securing element such as straps, ties, wire, rope, belts, or clamps. Further as illustrated fluid activated retrieval device 320 includes two or more strap guides 322 that may be utilized in combination with leg 324 for receiving a securing element such as straps, ties, wire, rope, belts, or clamps. Still further as illustrated fluid activated retrieval device 330 includes two or more strap guides 332 that may be integrated with leg 334 for receiving a securing element such as straps, ties, wire, rope, belts, or clamps.
FIG. 4 is an illustrative representation of deploying a fluid activated retrieval device in accordance with embodiments of the present invention. At a first step 400 , fluid activated retrieval device 404 is illustrated prior to deployment and mounted on object 402 . Reactant 406 is illustrated as being dispersed throughout the fluid activated retrieval device. As contemplated herein, a reactant may be selected to interact with a particular fluidic medium to produce a reactant gas. In embodiments, a reactant may include a mixture such as: a citric acid/sodium bicarbonate mixture, a tartaric acid/sodium bicarbonate mixture, and an acetic acid/sodium bicarbonate mixture. In one preferred embodiments, the citric acid/sodium bicarbonate mixture includes a formula of 50% citric acid (C 6 C 8 O 7 ) and 50% sodium bicarbonate (CHNaO 3 ). It may be appreciated that since the reactant is dispersed through the fluid activated retrieval device an anti-agglomeration agent compatible with the reactant may be included to prevent caking in some embodiments. Still further, in some embodiments, the reactant may further include a desiccating agent to prevent unwanted reactions due to any residual humidity remaining in the fluid activated retrieval device during assembly.
At a next step 410 , fluidic media 412 is represented as entering the fluid activated retrieval device 404 through port passages and ports. Fluidic media, as disclosed herein may include any number of mediums such as, an aqueous medium, a petroleum based medium, and an organic solvent medium without departing from embodiments disclosed herein. As noted above, diaphragm embodiments, when installed properly, may serve to selectively allow fluidic media to enter the hollow base cavity whereupon the fluidic media interacts with a reactant in the hollow base cavity to produce a reactant gas. At a step 420 , reactant gas 424 is illustrated as having produced a pressure sufficient to deploy ( 422 ) the fluid activated retrieval device. In embodiments, the reactant gas produces a deploying pressure of at least 2-40 PSI in excess of surrounding environment pressure. Once the fluid activated retrieval device is deployed, deployable float housing 432 rises to surface 434 . During the rise to the surface, line 436 is deployed. Deployable float housing 432 may then be retrieved whereupon object 402 may be retrieved.
While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents, which fall Within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. Furthermore, unless explicitly stated, any method embodiments described herein are not constrained to a particular order or sequence. Further, the Abstract is provided herein for convenience and should not be employed to construe or limit the overall invention, which is expressed in the claims. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
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Fluid activated retrieval devices for retrieving an object from a fluidic medium are presented including: a hollow base having a cavity formed therein, where the hollow base includes, a port disposed along an outer surface of the hollow base, the port configured to provide passage of the fluidic medium to the cavity, a diaphragm disposed along the cavity and proximate to the port, and an anchor disposed along the cavity for securing a line; a deployable float housing removably attached with the hollow base, the deployable float housing having another cavity formed therein, where the deployable float housing includes, a buoyant chamber disposed along a distal end of the other cavity, a spool for receiving the line, the spool disposed within the second cavity and attached with the deployable float housing; and a reactant disposed in the cavities.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2013-0153193, filed on Dec. 10, 2013, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention disclosed herein relates to a method of manufacturing a flexible substrate allowing an electronic device to be mounted thereto, and more particularly, to a method of manufacturing a flexible substrate allowing an electronic device to be mounted thereto, wherein reliability is improved.
[0003] Currently, display apparatuses visually represent information input in various schemes such that a human can recognize. In order to visually representing the information input to the display device, an electronic device is necessary to be driven.
[0004] Nowadays, the electronic device for driving the current display device tends to be miniaturized and highly integrated, and is applied to application fields, such as a flexible display field, a medical industry field applicable to electronic skin, and a sensor field. The electronic device applied to the applications is required not to be damaged by external stress. Accordingly, the electronic device is applicable to the applications by being mounted on a stretchable substrate which can be freely bent or folded.
[0005] Fabrication of waves on the stretchable substrate has benefits in that metal interconnections formed on the substrate are not cut or damaged even when the substrate is stretched. Accordingly, wave fabricating methods has been variously proposed.
SUMMARY OF THE INVENTION
[0006] The present invention provides a method of manufacturing a flexible substrate allowing an electronic device to be mounted thereto, wherein reliability is improved.
[0007] Embodiments of the present invention provide methods of manufacturing a flexible substrate allowing an electronic device to be mountable thereto, the method including: preparing a substrate; applying a force to the substrate to stretch the substrate in horizontal direction; performing a surface treatment process on the substrate and forming a first region having a plurality of wavy surfaces; and forming an electrode on the first region.
[0008] In some embodiments, the surface treatment process may be any one of an ultraviolet-ozone (UV-O3) process, an O2 plasma process, and a sputtering plasma process.
[0009] In other embodiments, the forming of the first region comprises, disposing a mask having an opening on the substrate; and performing the surface treatment process on the mask to activate a surface of the first region of the substrate which is exposed by the opening.
[0010] In still other embodiments, the activating of the surface of the first region may include modifying a surface of the first region from a hydrophobic surface into a hydrophilic surface.
[0011] In even other embodiments, the plurality of wavy surfaces may have a constant width and repeated in a constant period.
[0012] In yet other embodiments, the width of the wavy surfaces may become wider as plasma intensity is stronger and a plasma treatment time is longer in the surface treatment process.
[0013] In further embodiments, the applying of the force to the substrate may include stretching a horizontal length of the substrate by 1% to 40% than that before being stretched.
[0014] In still further embodiments, the forming of the electrode may include conformally applying a metal material to the first region along the wavy surfaces.
[0015] In even further embodiments, the electrode may include tungsten (W), copper (Cu), aluminum (Al), chromium (Cr), molybdenum (Mo), silver (Al), or gold (Au).
[0016] In yet further embodiments, the substrate may further include a second region, wherein the second region is a region that is not exposed to the surface treatment process and an electronic device is formed on the second region.
[0017] In much further embodiments, the method may further include removing the force applied to the substrate after forming the electrode on the first region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the drawings:
[0019] FIG. 1 is a flowchart illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention;
[0020] FIGS. 2A to 2F are perspective views illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention;
[0021] FIG. 3 is a perspective view illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention, wherein a part A of FIG. 2D is enlarged;
[0022] FIG. 4 is a perspective view illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention, wherein a part B of FIG. 2E is enlarged; and
[0023] FIGS. 5A to 5C are perspective views illustrating a deformed size of a flexible substrate according to plasma intensity and plasma treatment time in a surface treatment process according to an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Like reference numerals refer to like elements throughout.
[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0026] Example embodiments are described herein with reference to cross-sectional views and/or plan views that are schematic illustrations of example embodiments. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but may be to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle may, typically, have rounded or curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes may be not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of example embodiments.
[0027] Hereinafter, it will be described about an exemplary embodiment of the present invention in conjunction with the accompanying drawings.
[0028] FIG. 1 is a flowchart illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention. FIGS. 2A to 2F are perspective views illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention. FIG. 3 is a perspective view illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention, wherein a part A of FIG. 2D is enlarged. FIG. 4 is a perspective view illustrating a method of manufacturing a flexible substrate according to an embodiment of the present invention, wherein a part B of FIG. 2E is enlarged. FIGS. 5A to 5C are perspective views illustrating a deformed size of a flexible substrate according to plasma intensity and plasma treatment time in a surface treatment process according to an embodiment of the present invention.
[0029] Referring to FIGS. 1 and 2A , a substrate 11 is prepared (step S 100 ). The substrate 11 may be a flexible substrate having elasticity, for example, a ploydimethylsiloxane (PDMS) substrate, a polymer substrate, or a rubber substrate.
[0030] A method of forming the substrate 11 is described. According to an embodiment, elastomer material (for example, liquid phase PDMS) and a curing agent (for example, dimethyl methylhydrogen siloxane) are mixed at a ratio of about 10:1 and a mixed solution is formed. After the mixed solution is formed, the mixed solution is put inside a vacuum chamber and kept about several hours in order to remove bubbles included in the mixed solution. The bubble-removed mixed solution is put inside an oven and coated by a dry or spin-coating method for about 2 hours to form the substrate 11 . When the substrate 11 is formed by the spin-coating method, the thickness of the substrate 11 may be adjusted by adjusting a revolution speed (rpm) and time.
[0031] Referring to FIGS. 1 and 2B , the substrate 11 is stretched and maintained by applying a force (step S 200 ). In detail, the substrate 11 may be stretched by applying a force and pulling it in one side or both sides by using equipment capable of stretching the substrate 11 . The substrate 11 may be stretched by ΔL, and ΔL may be about 1% to about 40% of the horizontal length L 0 of the substrate 11 .
[0032] Referring to FIGS. 1 , 2 C, 2 D, and 3 , a surface treatment process is performed on the substrate 11 and wavy surfaces 18 are formed on the substrate 11 (step S 300 ). The surface treatment process is performed on a mask 13 by disposing the mask 13 having openings 15 on the substrate 11 . With the surface treatment process, the wavy surfaces 18 may be formed locally on the surface of the substrate 11 exposed by the openings 15 . Regions on which the wavy surfaces 18 are formed are interconnection regions 17 a and the remaining region except the interconnection regions 17 a is a device region 17 b . That is, the interconnection regions 17 a are regions on which the interconnections connecting electronic devices are formed, and the device region 17 b is a region on which the electronic devices are disposed. The device region 17 b of the substrate 11 , which is not exposed on the surface treatment process, maintains a flat surface. The surface treatment process may be, for example, an ultraviolet-ozone (UV-O 3 ) process, an O 2 plasma process, or a sputtering plasma process.
[0033] The UV-ozone (UV-O 3 ) process is a surface treatment process using ozone O 3 . In detail, ozone O 3 is generated through a UV ozone processing apparatus and the ozone activates the surface of the substrate 11 . Accordingly, the surface of the substrate 11 changes from a hydrophobic surface into a hydrophilic surface.
[0034] The O 2 plasma process is a surface treatment process using oxygen plasma ions. In detail, oxygen plasma ions (O 2− ions) are generated through an oxygen gas in a plasma generating apparatus. The O 2− ions activate and are combined with the surface of the substrate 11 . The O 2− ion combined surface of the substrate 11 is changed from a hydrophobic surface into a hydrophilic surface.
[0035] The surface treatment process may cause surface oxidation of the substrate 11 . For example, when the substrate 11 is a PDMS substrate, —CH 3 of an end group having strong hydrophobicity, which is combined with the surface of the substrate 11 , is substituted with —O or —OH group to allow the surface of the substrate 11 to have a covalent bond of a Si—O—Si structure having strong hydrophilicity. The substrate 11 modified to have strong hydrophilicity by the surface treatment is an oxidized region, namely, the interconnection regions 17 a , and the wavy surfaces 18 may be formed on the interconnection regions 17 a .
[0000]
[0036] One or more wavy surfaces 18 may be formed on the interconnection regions 17 a . When the interconnection regions 17 a are formed of a plurality of wavy surfaces 18 , the wavy surfaces 18 have a constant width and may be repeated in a constant period. The width of the wavy surfaces 18 may be differed by adjusting plasma intensity and plasma treatment time in the surface treatment process.
[0037] In detail, referring to FIGS. 5A to 5C , as the plasma intensity is stronger and the plasma treatment time is longer in the surface treatment process, the wavy surfaces 18 may be formed to have a larger width.
[0038] When the wavy surfaces 18 are formed on the entire surface of the substrate 11 , the disposition of the mask 13 may be omitted and the surface treatment process may be performed.
[0039] Referring to FIGS. 2E and 4 , electrodes 19 are formed on the interconnection regions 17 a of the substrate 11 (step 400 ). The electrodes 19 may be formed conformally on the interconnection regions 17 a along the wavy surfaces 18 . The electrodes 19 may be formed by using a chemical vapor deposition (CVD), a physical vapor deposition (PVP), or an atom layer deposition (ALD). The electrode 19 may include a metal material, such as tungsten (W), copper (Cu), aluminum (Al), chromium (Cr), molybdenum (Mo), silver (Al), or gold (Au).
[0040] Referring to FIGS. 1 and 2F , the force applied to the substrate 11 is removed (step S 500 ). Accordingly, the substrate 11 returns to have the initial horizontal length L 0 . The electrodes 19 formed on the substrate 11 may maintain their shapes without deformation or brokenness, although the substrate 11 is stretched by about Lo+ΔL.
[0041] Although not shown in the drawing, an electronic device (not shown) may be formed on the device region 17 b of the substrate 11 . The electronic device may be a transistor.
[0042] According to an embodiment of the present invention, the interconnection regions 17 a of the substrate 11 , which have the wavy surfaces 18 , may be formed by the surface treatment process. Accordingly, despite of bending or pulling of the substrate 11 , the electrodes 19 formed on the interconnection regions 17 a can be prevented from being damaged and the electronic device formed on the device region 17 b can be stably driven. Furthermore, since the width and period of the wavy surfaces 18 can be adjusted according to process conditions in the surface treatment process, the substrate 11 can be used in various fields.
[0043] According to a method of manufacturing a flexible substrate that an electronic device is mountable according to an embodiment, interconnections can be formed on the substrate having wavy surfaces by the surface treatment process. Accordingly, an electronic device formed on a device region can be stably driven by preventing damages on the interconnections formed on an interconnection region.
[0044] The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
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Provided is a method of manufacturing a flexible substrate allowing an electronic device to be mounted thereto. The method of manufacturing a flexible substrate allowing an electronic device to be mountable thereto, includes preparing a substrate, applying a force to the substrate to stretch the substrate in horizontal direction, performing a surface treatment process on the substrate and forming a first region having a plurality of wavy surfaces, and forming an electrode on the first region.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part application of U.S. Patent Application Ser. No. 824,260, filed Aug. 15, 1977, entitled CARD, SYSTEM AND METHOD FOR SECURING PERSONAL IDENTIFICATION DATA, which is a continuation-in-part application of U.S. Patent Application Ser. No. 813,882, filed on July 8, 1977, entitled CARD, SYSTEM AND METHOD FOR SECURING USER IDENTIFICATION DATA.
BACKGROUND OF THE INVENTION
Many types of transaction cards (account cards, identification cards and the like) have been used by individuals to gain access to account files in a bank or similar institution to gain access to secure areas, or to initiate some similar transaction enabling them to access otherwise restricted information stored in the institution. Not infrequently, the person using the card is not the person to whom the card was issued (i.e., not an authorized user of the card), but a person who has found, stolen, or manufactured (perhaps duplicated) the card with the intent to use it illicitly.
Heretofore, relevant information such as account number or code, employee number, social security number and the like, has been included on the card such as by embossing, magnetically or optically encoding on the card, or the like. A card of this type, and a system which utilizes such a card, are shown, for example, in U.S. Pat. No. 3,862,716 entitled "Automatic Cash Dispenser and System and Method Therefor", issued Jan. 28, 1975 to Robert Black and Christopher Hall.
Because of the dire consequences usually occasioned by the breach of the security of such a card-utilizing system by an unauthorized card user, a more secure card and system which would make the probability of a breach more remote would be highly desirable. A card and a system for utilizing the card are needed which actively contribute to the security process by securing data entered into the system, rather than merely passively reproducing data which is prerecorded on the card.
SUMMARY OF THE INVENTION
In accordance with the preferred embodiment of the present invention, a card is provided having a plurality of optical ports or apertures formed in the substrate to serve as an optical encryption gate. The optical ports may be randomly disposed at intersections of rows and columns to provide an extremely large population of different cards, each of which can thus be uniquely associated with an individual user.
There is also provided a method of producing the card, and a system which utilizes the card to improve user identification and transaction security. The system comprises an optical reader with light-emitting diode (LED) signal sources, and detectors, a keyboard unit, and a processor or logic unit including circuits for driving the LED signal sources. Input data applied to the card via the logic unit and the signal sources are optically encrypted by the card to improve the security of the system and, hence, user identification in a secured transaction.
The system may also include a physical data collector or transducer for collecting fingerprint or voice-print data or the like from a user and for applying such data in digital form to the card via the logic unit and the card reader.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial diagram of a card of the present invention and of a card reader for reading the card;
FIG. 2 is a pictorial diagram of the card operating as an optical encoder;
FIG. 3 is a combined pictorial and block diagram of the card and system of the present invention;
FIG. 4 is a pictorial diagram of the card and card reader of FIG. 1 showing a selected data transformation operation;
FIG. 5 is a combined pictorial and block diagram of the card and card reader in a system which includes a selected algorithm for performing selected, irreversible data transformation operations; and
FIG. 6 is a combined pictorial and block diagram of the card and system including a data collector for entering fingerprint or voice-print data.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a card 11 of the present invention which may be produced by molding an opaque plastic material (such as opaque fiberglass reinforced nylon plastic, or Acrylonitrile Butadiene Styrene plastic, having an index of refraction which minimizes light diffusion therethrough) to form a non-light-conductive substrate. The optical ports 16 may simply be holes formed through the substrate 11 from one major face to the other face, or may be optical ports through the substrate 11 having surface-flush windows covering the ends of the port on both faces. These optical ports 16 are positioned at the intersections of columns and rows over a portion of the area of the card. In one embodiment of the present invention, only one optical port 16 is located along one row. In addition, as shown in the scanning device of FIG. 2, a reference track of optical ports 18 may also be included on the card to provide information about the column in which an optical port 16 appears. A card 11 thus formed does not contain any particular code, but instead is an optical encrypting device which has a random encryption scheme associated therewith. And, in a population of such cards prepared in accordance with the present invention, each card is different and can be uniquely associated with one authorized user. Information such as account balance, etc., may also be recorded on the card by such conventional means as a magnetic stripe 21, embossed characters, or the like.
In using the card 11 to initiate a transaction (e.g., to communicate a withdrawal or credit transaction to a computer system of a bank), the user first inserts the card 11 into the optical card reader 29 of the system illustrated in FIG. 1 in a manner such that one major face is positioned adjacent the LED light sources 25, and the opposite major face is positioned adjacent the detectors 27. A full matrix of LED sources 25 and a full matrix of detectors 27 may be employed to cover all possible locations of ports 16. Alternatively, the optical ports 16 may be scanned using one or more corresponding sets of aligned light source 25 and detector 27 which move relative to the card 11, or with respect to which the card 11 is moved, as shown in FIG. 2. In the embodiment of FIG. 2, the reference track of optical ports 18 is also scanned to provide information about in which column along a row an optical port 16 is detected.
Data in the form of binary bits from a processor or logic unit 31 are applied via input lines 33 to LED light sources 25, a data bit of "1" causing a respective LED to be turned "on", and a data bit of "0" causing the LED to be turned "off". When card 11 is properly inserted into reader 29 and the LED light sources 25 are energized to "on" and "off" states corresponding to applied data bits as shown in FIG. 2, then the card 11, by virtue of the locations of its optical ports 16, transforms or changes the pattern of the applied data bits detected by detectors 27. Thus, the encoding of applied data by the card itself is determined by the pattern of apertures relative to a reference column (or row) of apertures 18 as the card is moved relative to the reader. The apertures 16, 18 may thus be positioned (within the rows or columns) in a great many different patterns, each providing a distinctive card.
The system illustrated in FIG. 3 operates on the card 11 to secure user-identification data entered into the system by a card holder or user. The system of FIG. 3 comprises a keyboard 43, a card reader 29 for reading a card 11, and a processor or logic unit 31 for storing and processing data entered via the card reader and keyboard, and producing therefrom a secure user-identification code.
In response to card 11 being inserted into reader 29, logic unit 31 produces a card number (CN) identifying the card by applying a fixed, preselected input bit pattern (e.g., an eight-bit pattern of "10101010") to the LEDs 25 at the input port of reader 29. This turns "on" and "off" the LEDs in correspondence with the input bit pattern. The "on" LEDs apply light signals to corresponding (matching) optical ports of the card, either in a full matrix of LEDs and detectors, or in a scanning arrangement using one set of LEDs and detectors which move relative to the card, as described above. This allows the card to transmit or optically gate selected ones of the applied light signals to the detectors 27 which sense the optically gated pattern of light signals to produce a corresponding output bit pattern representing a unique card number (CN) identifying the card 11.
In addition to producing a unique card number (CN), the system of FIG. 3 provides for entry of a user's secret code (a code or personal identification number known only to the user or person making the transaction) into the system. After inserting his card 11 into reader 29, the user enters his secret code into the system via keyboard 43. In response to the inserted card, logic unit 31, in conjunction with card 11 and card reader 29, produces a unique card number (CN) as described above, and stores the CN in buffer memory in the logic unit 31. Thereafter, upon entry of the user's secret code (Personal Identification Code, PIN), logic unit 31 applies both the CN and the PIN (sequentially, interdigitally, or in parallel) to card reader 29 and card 11, as shown in FIG. 4. Card 11 transforms the applied data (PIN + CN) to an encrypted form (PIN + CN)' in a manner consistent with the orientation of its optical ports. This transformed or encrypted data (PIN + CN)' is then transferred to a computer system of the institution (e.g., bank) where it is compared with pre-stored data for verifying the correctness of the transformed data (PIN + CN)' and, hence, the correctness of the entered PIN (user's secret code) and of the card (optical port pattern) used.
In FIG. 5, an irreversible algorithm unit 45 (such as the encoding scheme described, for example, in U.S. Pat. No. 3,939,091, entitled "Personal Verification System" issued Feb. 10, 1976, to Martin M. Atalla and Alexander F. Liu, or, for example, the National Bureau of Standards encryption-decryption integrated circuit chip commercially available from Motorola Company) is included in the system for receiving the transformed (PIN + CN)' data and producing therefrom a user ID (identification) number. Irreversible algorithm unit 45, which may represent the institution's own ID or its computer system's ID, increases the security of the system by making the process of producing an ID number from a transformed (PIN + CN)' irreversible (i.e., making it essentially impossible to reproduce the transformed (PIN + CN)' from the ID number, using unit 45). For added security, the transformed (PIN + CN)' may be combined with the generated card number CN or with a user account number or some other identification data, prior to its application to irreversible algorithm unit 45.
An alternative embodiment of the system of the present invention is shown in FIG. 6. To provide still greater security of user-identification data entered into the system, and ensure successful use of the system by authorized users only, a physical data collector 47 may be included in the system for receiving physical data from the user, i.e., Physical Identification Data (PID) such as fingerprint, voice-print, signature dynamics information and the like that are unique to the user.
The physical data collector 47 may be a commercially available transducer with optical scanning and detecting capabilities for scanning and detecting a user's fingerprint and converting the fingerprint to digital form for application to card reader 29 and card 11 via logic unit 31. Alternatively, collector 47 may be a commercially available voice-print recorder capable of recording and generating a voice-print of the user's voice and converting the voice-print recording to digital form for application to card reader 29 and card 11 via logic unit 31. Also, the physical data collector 47 may be a conventional signature digitizer or similar conventional transducer which operates on the dynamics of a user signing his name. As shown in FIG. 6, logic unit 31 may combine the CN (card number representing the optical port pattern of the card) and PIN data (the user's secret code described above) with the PID digital data, by applying one or more of the CN, PIN and PID digital data, alone or in combination (sequenttially, interdigitally, or in parallel), to card reader 29 and card 11. Card 11 transforms the applied data (e.g., PIN + CN + PID) to an encrypted form (PIN + CN + PID)' in a manner consistent with the orientation of its optical ports. This transformed or encrypted data (PIN + CN + PID)' is then transferred to the computer system of the institution, where it is compared with pre-stored data verifying the correctness of the transformed PIN', CN' and PID' and, hence, the correctness of the entered PIN in conjunction with the card used, and with the particular user as identified by the PID representing the user's fingerprint or voice-print, or signature, or the like.
Alternatively, the PIN data may be omitted and the applied data for encryption becomes (PID + CN) which is transformed via the card 11 and reader 29. This transformed or encrypted data (PID + CN)' is then transferred to the computer system of the institution, for example, via an irreversible algorithm of the type referred to at 45 in FIG. 5. The transformed data may then be compared with prestored data for verifying the correctness of the transformed data in a manner as previously described.
Thus, from the foregoing description of the optically-ported card and system for utilizing the card, a unique method and means are presented for securing user-identification data.
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A card having randomly-oriented optical ports and a system having a card reader for reading the card and having a keyboard for entering secret user-identification data are disclosed for securing the user-identification data entered into the system. The system includes a logic unit for controlling the keyboard, and for applying data to the card via the card reader. The system may also include a physical data collector or transducer for collecting fingerprint or voice-print data, or the like, from a user and for applying such data in digital form to the card via the logic unit and the card reader. The card operates in conjunction with the logic unit of the system to transform the applied data and to improve the security of said data. A method of fabricating the card and a method of securing entered data using the card are also disclosed.
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This invention was made with Government support under Contract No. DMR-8460341, awarded by the National Science Foundation. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
The present invention relates to novel fluorinated carbons, and more specifically, to improved amorphous, crystalline and glassy or vitreous fluorinated carbons, products made therefrom and methods of manufacture.
Carbons, which includes both amorphous and crystalline types like carbon blacks, lamp black, graphitic and pyrolitic types, to name but a few, find use in a multitude of important and often critical applications in modern technology ranging from motor brushes, lubricants, batteries, fuel cells, plastic refractories, heat exchangers, composites, nuclear generators, resistors, catalyst supports and so on. A major shortcoming, however, in many applications for carbons is often the limited useful life as a result of oxidative degration.
One solution to the problem of oxidative degration has been the direct fluorination of carbon with elemental fluorine. Direct fluorination methods are disclosed by W. O. Teter el al in U.S. Pat. No. 2,786,874 (1957), J. L. Margrave in U.S. Pat. No. 3,674,432 (1972), D. T. Meshri et al in U.S. Pat. No. 3,929,918 (1975) and T. Komo et al in U.S. Pat. No. 3,929,920 (1975).
Fluorographites, for example, prepared by the direct fluorination method are typically hydrophobic, possess high temperature stability, are insoluble in organic solvents and are relatively unreactive, being attacked neither by strong acids nor by alkalies. They may be represented empirically as (CF x ) n where their specific properties depend on the values for x and n. Fluorographites, for instance, in the range of CF 0 .5 to CF 1 .0 are used in lithium CF x batteries as positive electrodes. These batteries possess a high energy density of 320 to 470 watt hour/kg, a high open circuit voltage of 2.8 to 3.2 volts, a high working voltage of about 2.6 volts and a long shelf life. However, the useful range of fluorographite batteries prepared by the direct fluorination method is limited because as values for x increase resistivity greatly increases. In fact, the highly fluorinated material CF 1 .1 is almost an insulator or nonconductor.
Not only is fluorographite, for example, manufactured by a costly somewhat hazardous process by direct fluorination with fluorine gas, but frequently undergoes degradation in the process. Strong, highly reactive fluorinating agents, such as elemental fluorine, ClF 3 , ClF, CoF 3 , etc., have a tendency to produce nondiscriminating reactions with carbon molecules even causing fragmentation of edge sites, grain boundaries, dislocations and other surface imperfections. Strong, nonselective fluorinating agents tend to fluorinate olefinic and aromatic carbon to carbon unsaturation sites, adding to the layered planes of benzene rings of the molecule to provide nonconductive carbons.
According to the present invention, it was discovered that "soft" fluorinating agents are more selective in their attack of functional groups, showing less tendency to degrade and fragment edge sites, grain boundaries, etc., than strong fluorinating agents, like elemental fluorine. That is to say, it was found that soft fluorinating agents, like SF 4 will not react with carbon to carbon olefinic bonds in carbon structures, but instead react with carbon-oxygen bonds to replace oxygen with fluorine at edge sites, grain boundaries, dislocations and other surface imperfections, which are also the same sites where oxidative attack of carbons usually occur. Accordingly, it was postulated that if most potentially oxidation sensitive regions of carbon structures could be selectively fluorinated stable graphite and other carbons could be prepared with greatly improved life expectancies while retaining their desired thermal and electrical properties.
A. C. Teter in U.S. Pat. No. 3,340,081 recognized the incidental presence of surface oxygen in commercial carbon blacks. However, Teter failed to recognize the beneficial effect of specifically pretreating carbon blacks before fluorination to first develop most of the sites of potential instability to oxidative corrosion and degradation. Instead, without further oxidative pretreatment, Teter proceeded directly to fluorinate commercial carbon black with SF 4 or other organic sulfur trifluoride fluorinating agent to a maximum level of 7 percent by weight fluorine to prepare reinforcing agents for butyl rubber vulcanizates.
Accordingly, one aspect of the present invention relates to novel fluorinated amorphous and crystalline carbons and methods of manufacturing such carbons which have longer life expectancies, yet materially preserve their desirable thermal and electrical properties. By developing essentially all such potential sites of oxidative corrosion and degradation prior to fluorination, carbons having higher levels of fluorination can be prepared at relatively low cost by less hazardous specific fluorination methods.
Fuel cells require the use of gas (air or oxygen) depolarized electrodes which are comprised of highly sophisticated mixtures of various carbons, catalysts and polymers, along with other additives, and supportive structures which make up a solid composite electrode. The successful operation of a fuel cell electrode is governed by establishing three-phase interface sites: gas (usually oxygen or air), electrolyte solution (often aqueous acid or base) and the solid composite electrode. However, after extended use, depolarized carbon electrodes tend to become oxidized, lose their hydrophobic properties and "flood" when electrolyte penetrates into their porous structures. Electrolyte solution is drawn further into the electrode structure with eventual depletion of the useful three-phase interface sites. Furthermore, once flooding has ocurred the problem is often irreversible and the fuel cell becomes inoperable. This surface oxidation of carbons and tendency to transform from hydrophobic to hydrophilic properties is also a problem in metal air batteries, e.g. zinc-air batteries and in bifunctional air electrodes. The problem is especially severe in bifunctional air electrodes, since in this instance the gas diffusion electrode acts as an oxygen-evolving electrode in the charge step and is further oxidized. To overcome these problems, workers have sought to use more stable carbons like graphite carbons prepared under special conditions at high temperatures. Catalysts have also been incorporated into composite electrode structures to destroy peroxide species, which form to some extent with reduction of the oxygen or air feed, and which accounts for some of the oxidative degradation of carbon surfaces.
Accordingly, a further aspect of the present invention is the preparation of improved fluorinated carbon composites, including fuel cell electrodes, metal-air batteries and bifunctional air electrodes. The improved fluorinated carbons more effectively protect sites on the carbon electrodes which would otherwise be prone to flooding and additional degradation. The present invention also provides a method for regenerating spent-flooded gas diffusion electrodes for reuse by specific fluorination, as described in further detail below.
It has been known for many years that ozone, O 3 , could be produced electrochemically using various kinds of anodes, e.g. lead dioxide and platinum, in cold acidic electrolyte solutions, like sulfuric acid and phosphoric acid. In most cases, however, the energy conversion efficiencies were found to be low. More recently, Foller et al reported in CEP. (49-51), Mar. 1985 that ozone could be generated at much higher current efficiencies using vitreous or glassy carbon anodes in a 48 percent aqueous tetrafluoboric acid solution. In spite of the apparent advantages of electrochemical ozone generation with vitreous carbon anodes their exposure to highly corrosive acidic electrolytes has been found to shorten their useful life expectancies, making them a less attractive alternative. Moreover, current efficiencies for ozone are still too low and uneconomical for many applications.
Accordingly, a further aspect of the present invention, relates to the discovery that fluorination of vitreous or glassy carbons results in a material which is considerably more stable to corrosion in cold aqueous acids, including sulfuric, phosphoric and tetrafluoboric acids making such carbons currently more suitable and economical as anodes in the electrochemical generation of ozone as well as for other uses as anodes, such as persulfate formation.
SUMMARY OF THE INVENTION
The present invention relates to specifically fluorinated carbons and methods of manufacture, including specifically fluorinated amorphous, crystalline and vitreous carbons. The fluorinated carbons are characterized by improved chemical and/or electrochemical stabilities to corrosion, enhanced hydrophobic properties, lubricating properties, chemical and electrochemical catalysis, and support structure for deposited catalysts, while maintaining all or virtually all the desirable physical and chemical properties, e.g. thermal and electrical conductivities, for which a particular carbon or graphite was chosen. Accordingly, the fluorinated carbons, amorphous, crystalline and vitreous types, are adaptable to a wide range of applications which take advantage of these properties, such as in fuel cells, batteries, specialty electrodes, catalyst supports, lubricants, liners for chemical reactors, structural composites with metals and polymers for nuclear reactors, heat exchangers and seal rings. Many of such applications take advantage of both the surface and bulk chemical and physical properties of the carbons.
The specifically fluorinated carbons are prepared by preoxidizing discontinuities, edge sites and grain boundaries to form carbon-oxide groups at essentially all primary sites of oxidative instability on the carbon structure, followed by highly selective and relatively mild fluorination of the preoxidized carbon with a "soft" fluorinating agent, such as sulfur tetrafluoride or any other fluorinating agent capable of specifically substituting carbon-oxygen functionality with carbon-fluorine groups. Thus, the invention contemplates fluorinated carbons having fluorine covalently bonded to discontinuities, carbon edge sites and grain boundaries of carbon structures. By contrast, sites of olefinic and aromatic carbon-to-carbon unsaturation, including carbon basal planes in more structured graphitic type carbons are substantially free of such bonded fluorine.
According to the present invention, amorphous carbons and crystalline carbons are fluorinated with a soft fluorinating agent to a fluorine content up to about 20 percent and 10 percent by weight, respectively. However, the mildly fluorinated carbons can be fluorinated to even higher levels by post fluorinating with "hard" fluorinating agents, like elemental fluorine which add to sites of olefinic and aromatic carbon to carbon unsaturation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, carbons are preoxidized to more fully develop potential sites of instability with the ultimate objective of protecting those regions with stable carbon-fluorine bonds.
Carbons found most suitable for use in accordance with the invention are selected from amorphous or microcrystalline and crystalline types. Amorphous carbon is intended to mean imperfectly ordered molecular structures having relatively high surface areas, and which may also possess some incidental reactive oxygen sites. Here, planes of atoms are layered, irregular and unoriented without extensive growth in any direction. Cross-linking between the planes accounts for their greater hardness and mechanical strength compared to graphitic structures which lack cross-linking of planes. Controlled heating can often convert them to graphitic carbons. Amorphous carbons include carbon blacks, like lamp black, thermal black, channel black, acetylene black and furnace blacks. Other amorphous carbons include activated carbons, vitreous or glassy carbons, chars, soot, charcoal, and the like. They are commercially available in various forms including powders, woven carbons, felts, carbon fibers, to name but a few.
In contrast to amorphous type carbons are the crystalline or graphitic type carbons, e.g. graphites and pyrolytic graphites, which exhibit a more ordered molecular structure, closer spacing between monoplanes and stacks and relatively low surface areas, and therefore, have greater stability to oxidation. They have substantially better electrical and thermal conductivities than amorphous carbons and are available as powders, woven materials, felts, fibers and other forms.
The present invention contemplates fluorination of virtually all forms of carbons, including powders, fibers, flakes, as well as solid masses of any crystallographic orientation, crystallite size, interlayer spacing, interatomic distance, density, porosity, particle size or shape. However, the fluorination methods of this invention extend beyond carbons per se, but can also be used in fluorinating various "carbon substrates", which term is intended to mean carbon containing materials and articles like carbon steels which are alloys of iron. In carbon steels or mild steels carbon is the most important alloying element although such steels usually contain less than 1.5 weight percent carbon. Composites are also included within the meaning of the expression "carbon substrates". Composites are intended to mean two or more chemically distinct materials with a distinct interface separating the components. Composites usually comprise carbon or graphitic fibers or cloth as a reinforcing agent in a more ductile matrix, such as epoxy or other resin or plastic material, although a metal matrix can also be employed. Carbon or graphite powders can also be used in composities in which two different forms of carbon are used in the same structural unit.
Solid carbons and graphites, such as electrodes are also carbon substrates within the meaning of the foregoing definition treatable according to the present invention. Electrodes may be formed by high temperature sintering of carbon or graphite powders, flakes or other carbonizable materials with binders, like oil, pitch or tar. These materials are first mixed and then extruded, shaped or molded and then fired to a temperature to carbonize the binder. Further firing at higher temperatures may also be carried out to graphitize the mass. The solid mass will usually be substantially porous, which can be reduced by impregnating with a carbonizable material and then fired.
Because of the broad variety of carbons and carbon-substrates suitable for fluorination according to the present invention there may be wide differences in the level of chemically bonded fluorine. Fluorination occurs at the edge sites of planes and at imperfections on surface layers. Edge and plane defects are more numerous in the amorphous carbons, e.g., charcoal, coke and the carbon blacks than in graphitic carbons. As a result, the amorphous carbons are more readily fluorinated than graphitic carbons, and can be fluorinated to higher levels than crystalline carbons. Pyrolytic graphite has a near perfect crystal structure and will have low levels of bonded fluorine. Carbon blacks for purposes of the present invention will be specifically fluorinated to a minimum of at least 8 percent by weight fluorine, and more particularly, from 8 to about 20 percent by weight. Other amorphous carbons, e.g. activated carbons, chars, coke, vitreous or glassy carbons, etc. in powder form, cloths, felts, fibers, carbon substrates and the like will be fluorinated to at least 0.1 percent by weight, and more particularly, from about 0.1 to about 20 percent by weight. In the case of crystalline carbons, they will be specifically fluorinated to at least 0.01 percent by weight fluorine, and more particularly, from about 0.01 to about 10 percent by weight.
The expressions--specific fluorination or specifically fluorinated carbon--for purposes herein are intended to mean fluorination of carbons at locations of instability, e.g. edge sites, dislocations, grain boundaries and other similar regions as they occur in carbon structures, which locations have carbon oxide functionality selectively fluorinated to form stable carbon-fluorine bonds thereat. Specifically fluorinated carbons may be formed by the steps of preoxidizing potential sites of instability to form carbon-oxide surfaces. The preoxidized carbon or carbon substrate is then fluorinated with a "soft" fluorinating agent to convert these carbon oxide groups to stable fluorocarbon bonds thereby protecting these otherwise unstable sites. Thus, for most embodiments the initial step of the invention provides for developing the unstable sites and regions by oxidation to form carbon-oxide surfaces. As used herein, the terms "oxidation" and "preoxidation" with respect to carbon surfaces are intended to mean the specific development of sites of potential instability to oxidative corrosion and degradation in carbons and carbon substrates by forming reactive oxides thereat at levels in excess of those present before such development. It is also to be understood, the term--surfaces --with regard to the steps of preoxidation and specific fluorination is not intended to be limited to the outermost layers of the carbons but may also include interior substructures, depending on the type of carbon, density or degree of porosity of the material being treated.
Developing the potential sites of instability by preoxidation can be performed chemically or electrochemically. Chemical oxidation methods are carried out by immersion of the carbon or carbon substrate in aqueous and non-aqueous oxidizing solutions, containing such oxidizing agents as nitric acid, potassium permanganate, sodium hypochlorite and ammonium persulfate. Chemical oxidation also includes thermal methods where the carbon is heated in the presence of oxygen, air or carbon dioxide. Chemical oxidation of carbon has been described by H. P. Boehm, et al, Angew Chem. Internat. Edit, 3,669 (1964) and, Anorg. Chem. 353,236 (1967).
In an alternative method, carbons can be electrochemically preoxidized, for example, in 15 percent aqueous sulfuric acid by polarizing the carbon anodically. Electrochemical oxidation of carbon is described by N. L. Weinberg, and T. B. Reddy, J. Appl. Electrochemistry 3,73 (1973). Using such methods, the principal carbon oxide species formed are the strongly acidic carboxylic acid, weakly acidic carboxylic acid, phenolic hydroxyl and carbonyl groups. The electrochemical method of carbon oxide formation is generally preferred over the chemical method for electrode uses because of better reproducibility and convenience.
In treating carbons, they are usually preoxidized to further develop most or essentially all the potential sites of instability. However, at minimum the carbon is oxidized at least to a level of oxidation consistant with the desired level of specific fluorination. Thus, chemical or electrochemical preoxidation is conducted to a level, such that specific fluorination with, e.g. sulfur tetrafluoride, provides carbons generally with about 0.1 to about 20 percent by weight fluorine. Those carbons like carbon blacks having some incidental reactive oxygen sites are preoxidized to more fully develop potential sites of instability. That is, carbon blacks, for instance, having 5 percent by weight surface oxygen will be developed to at least 8 percent by weight and subsequently fluorinated to convert the carbon-oxide groups to stable fluorocarbon bonds.
As a further aspect of the invention, in certain embodiments the preoxidation step is performed in-situ, and therefore, a separate step for developing all potential sites of oxidative corrosion and instability can be omitted. That is, in regenerating spent electrodes, for example, a separate oxidizing step to fully develop the edge sites, grain boundaries, etc., prior to fluorination can be dispensed with because the electrode surfaces were oxidized in the course of regular use. Oxidation of the electrode surfaces caused them to become hydrophilic and to flood. Hence, essentially all potential sites have been fully developed in-situ during use, and the spent electrodes can be regenerated by specifically fluorinating with a soft fluorinating agent, etc. However, it is to be understood that electrodes not previously used, and therefore not oxidized can be preoxidized and specifically fluorinated according to the methods disclosed herein.
Preferably, before specifically fluorinating, the carbon or carbon substrate is cleaned by the steps of washing thoroughly in water to remove any oxidant or other reagent, and then thoroughly dried since water vapor remaining in the oxidized carbon will tend to react with the specific fluorinating agent consuming, and hence wasting the agent until all the water is reacted. Drying may be performed in a suitable dessicator or reactor in an inert atmosphere at about 100° to about 400° C., and more preferably, at about 200° to about 300° C. Drying may be accelerated if conducted under vacuum.
The carbon is then specifically fluorinated with a "soft" fluorinating agent which, for purposes of the present invention is intended to mean a fluorine-containing compound which will not cause carbon-to-carbon fragmentation, but instead will react with carbon-oxygen bonds with replacement of oxygen by fluorine. Generally, such agents will not react with olefin carbon-to-carbon sites in the carbon structure. Soft fluorinating agents include compounds of the formula:
R--SF.sub.3
wherein R is fluorine, alkyl, aryl aralkyl or dialkylamino.
Specific representative examples of soft fluorinating agents are: sulfur tetrafluoride, n-propylsulfur trifluoride, decysulfur trifluoride, cyclopentylsulfur trifluoride, diethylaminosulfur trifluoride, dimethylaminosulfur trifluoride, phenylsulfur trifluoride. Also included, are the alkyl - and arylsulfur trifluorides prepared and described by W. A. Sheppard, J. Am. Chem. Soc. 84, 3058 (1962).
Specific fluorination with the soft fluorinating agents form trifluorocarbon, difluorocarbon and monofluorocarbon bonds from carboxyl, carbonyl and hydroxyl groups respectively. Fluorination is conducted to the extent that the carbon or graphite is stabilized, or substantially all carbon oxide functionality is converted to carbon-fluorine bonds. It may be carried out in a suitable reactor usually first flushed with a dry inert gas, e.g. nitrogen. If, for instance, sulfur tetrafluoride is used, the reactor or pressure vessel is usually cooled with, for example, a bath of dry ice-acetone, evacuated to about 1 mm of pressure and sulfur tetrafluoride, for example, then introduced in excess. After sealing the vessel it is warmed gradually and then heated for varying lengths of time, up to about 25° to about 500° C., and more preferably, from about 100° to about 250° C. The reaction time may be about 15 minutes to about 10 days depending on the temperature. The reaction pressure may vary from about atmospheric to about 500 psig. Depending on the intended use of the selectively fluorinated carbon or carbon substrate the amount of soft fluorinating agent, e.g. sulfur tetrafluoride employed can be substantially less than the estimated equivalent needed to convert all carbon "oxide" functionality, equivalent to the carbon oxide functionality, or up to an amount which is considerably more than that required stoichiometrically. If used in excess, sulfur tetrafluoride, for example, may be present in up to about 100 fold by weight or more of that amount actually required.
Other soft fluorinating agents like selenium tetrafluoride, diethylaminosulfur tetrafluoride and alkyl - or arylsulfur tetrafluorides and the like, as well as mixtures of these, may be conveniently used in an inert solvent, such as methylene chloride, chloroform, carbon tetrachloride and 1,1,2-trifluorotrichlorethane. The fluorinating agents in such solvents may be used at atmospheric pressure or above, and at temperatures, usually from room temperature and up to the boiling point of the solution. Because many of these fluorinating agents are liquids at room temperatures and above, they may also be used without a solvent. If a solvent is utilized it may be present in any concentration up to a large excess, such that the fluorinating agent is present in an amount from 1 to about 90 percent volume, and more preferably, from about 5 to about 75 percent.
Specific fluorination of the carbons may be performed in the presence of a sufficient amount of a catalyst, either fluorine or non-fluorine containing. Fluorinated catalysts include hydrogen fluoride, boron trifluoride, arsenic trifluoride, sodium and potassium fluorides, titanium tetrafluoride and lead tetrafluoride. Non-fluorine containing catalysts include lead oxide, titanium oxide, trimethyl and triethylamines and pyridine. All such catalysts are useful with soft fluorinating agents.
As an optional pretreatment step, prior to specifically fluorinating with soft fluorinating agent, dried oxidized carbons may be treated with a very soft fluorinating agent, much as hydrogen fluoride, potassium hydrogen fluoride, potassium fluorosulfinate, thionyl fluoride, cyanuric, etc. This optional pretreatment is useful for converting pendant carboxyl groups to acyl fluorides, and may be carried out, for example, by passing anhydrous hydrogen fluoride over heated carbon. Treatment with HF may run for several hours until substantially all reactive carboxylic acid, olefinic carbons and other more highly reactive sites have been partially fluorinated. One such method is also described in U.S. Pat. No. 3,929,918 (D. T. Meshri et al).
As a further optional step, the specifically fluorinated carbons may be further fluorinated with a "moderate" or "hard" fluorinating agent. That is, the specifically fluorinated carbon and carbon substrates having up to 20 percent by weight fluorine can be post-fluorinated to higher levels, i.e. 65 percent by weight fluorine, particularly in the case of amorphous type carbons. These post fluorinated specifically fluorinated carbons are specially useful as lubricants and in Li/CFx batteries.
Post fluorinations with "hard" fluorinating agents is intended to refer to fluorine-containing compounds which are capable of reacting nondiscriminatively with carbon molecules, and in some instances even result in their fragmentation. They tend to fluorinate olefinic and aromatic carbon-to-carbon unsaturation sites, adding to the layered planes of benzene rings of the carbon molecule. Representative examples include F 2 , ClF, ClF 3 , BrF 3 and MFn wherein M is cobalt, antimony, manganese, cerium or uranium and n is a number corresponding to the highest oxidation state of M.
The "moderate" fluorinating agents are fluorine-containing compounds which are somewhat less reactive and more selective than hard fluorinating agents, but are capable of producing reactions which are comparable to the hard fluorinating agents, and include such representative examples as HgF 2 , SbF 5 , SbF 3 /SbCl 5 , AsF 3 , CaF 2 , KSO 2 F, AsF 5 , etc.
After completion of the oxidation and all fluorination steps the specifically fluorinated carbon, graphite or carbon substrate is treated to remove any traces of unreacted fluorinating agents and byproducts. This may be accomplished, for example, by purging the fluorinated material with an inert gas followed by thorough washing in water, and drying under vacuum at 150° C. and 1 mm pressure.
The following specific examples demonstrate the various aspects of this invention, however, it is to be understood that these examples are for illustrative purposes only and do not purport to be wholly definitive as to conditions and scope.
EXAMPLE I
A sample of porous carbon identified as PC 58 from Stackpole Carbon Co., St. Marys, PA., which is largely amorphous carbon, weighing 17.8 g was thoroughly washed in water and then electrochemically oxidized in an unseparated electrochemical cell containing 5% aqueous sulfuric acid solution at 25° C. The Stackpole carbon sample served as the anode. A carbon rod was used as a cathode and a saturated calomel electrode (SCE) was placed near the anode to monitor and control the anode potential. The solution was magnetically stirred while the sample was electrochemically oxidized by means of a potentiostat at a controlled potential of +1.30 V vs SCE measured between the sample and SCE. The current was initially 600 mA at a cell voltage of 13 V. After 35 minutes the potential of the anode was increased to +2.50 V to provide a current of about 1.0 A at a cell voltage of 22 V. After passage of 17,200 coulombs the reaction was stopped and the oxidized sample washed well with distilled water and dried.
The oxidized sample was placed in a Monel pressure vessel in an efficient fume hood, cooled with dry-ice acetone, flushed with dry nitrogen, and evacuated to 1 mm with a vacuum pump. Sulfur tetrafluoride (about 45 g) was introduced and the reaction was held at room temperature at 105 psi for about 1 hour. Then the temperature of the reactor was raised to 150° C. and held at this temperature for 24 hours. On cooling to room temperature, excess reagent and gaseous products were vented into a trap containing aqueous caustic. The reactor and mildly fluorinated carbon was purged several times with dry nitrogen. The sample was removed, washed well with water and dried in a dessicator over P 2 O 5 in vacuo. The weight of the final sample was 18.2 g. The elemental analysis showed the presence of 4.0% fluorine.
To demonstrate the use of these fluorinated carbons in batteries, the specifically fluorinated carbon was placed in an electrochemical cell containing a counter electrode of lithium metal and an anhydrous solution of lithium perchlorate (0.25M) in propylene carbonate, under a helium atmosphere. An open circuit potential of 3.1 V was measured with a digital voltmeter. A current of about 2 mA was observed with a resistance inserted in the circuit of 1000 ohms.
EXAMPLE II
To demonstrate the results of chemical oxidation and fluorination, 50 g of carbon fibers available under the designation Thornel-50, a trademark of Union Carbide are placed in a glass beaker with 500 ml of aqueous sodium hypochlorite solution (5%), heated to 50° C. and magnetically stirred for 12 hours. The oxidized carbon fibers are rinsed in water, 5% aqueous sulfuric acid, washed well with water and then thoroughly dried.
The sample is next placed in a Monel reactor and heated to 200° C. at atmospheric pressure, while purging with a continuous stream of andydrous hydrogen fluoride for 5 hours. The reactor is then cooled, flushed with dry nitrogen, and 100 g of sulfur tetrafluoride is introduced, according to the method of EXAMPLE I. Upon reaction at 200° C. for 24 hours under pressure, the reactor is cooled and excess reagent and gaseous products vented and removed as before. The thoroughly washed and dried sample is next fluorinated in the same reactor, which is initially flushed with dry nitrogen, by slowly (about 10 ml/min) passing a dilute fluorine/nitrogen mixture (about 10% by volume F 2 ) over the sample for 30 minutes. During the course of this process the reactor temperature rises to about 250° C. as a result of the exothermic heat of reaction. The reactor and sample are next cooled by means of a stream of pure nitrogen which also serves to clean the carbon sample of absorbed gaseous contaminants. Finally, the sample is carefully washed and dried. Analysis shows that the fluorine content is significantly less in the mild fluorination step with SF 4 , but the fluorine content is substantially increased in the next step using the dilute fluorine mixture.
The sample is easily wetted after chemical oxidation demonstrating the hydrophilic nature of the carbon oxide surface. After fluorination with SF 4 and then with dilute fluorine, the samples are distinctly hydrophobic in character and water does not substantially wet the samples.
EXAMPLE III
A flooded air cathode available from Prototech, Newton Highlands, Ma., consisting of high surface area carbon and Teflon® fibers and containing 0.5 mg/cm 2 of platinum catalyst is removed from a phosphoric acid fuel cell which had been operating at 195° C. for 6 months but had failed. This electrode is observably hydrophilic and is prepared for specific fluorination by washing thoroughly in distilled water and drying at 100° C. in vacuo for 24 hours.
Upon mild fluorination with sulfur tetrafluoride, which is used in excess, the selectively fluorinated gas diffusion electrode, is removed from the reactor, washed well (it is observably hydrophobic), and returned to use in a phosphoric acid fuel cell.
EXAMPLE IV
A gas diffusion electrode having Catalogue No. PSN available from the Prototech Co. consisting of Vulcan XC-72 carbon mixed with Teflon® fiber, containing 0.5 mg/cm 2 of platinum catalyst, on a silver plated nickel screen is placed in a small test cell. A nickel electrode served as the counter electrode and the electrolyte is 23% aqueous NaOH solution at 75° C. Air is introduced to the gas side of the gas diffusion electrode, and at a current density of 300 amp/ft 2 , the electrode potential is -0.26 V vs Hg/HgO as a reference. After 1000 hours of continuous operation, the electrode potential is -0.26 V and after 20,000 hours, the electrode potential is degraded to -0.41 V vs Hg/HgO.
This irreversibly flooded gas diffusion electrode is removed from the cell, soaked in distilled water to remove caustic, thoroughly dried and fluorinated with SF 4 at 150 psi, 150° C. for 4 days. The electrode is washed with distilled water and remounted in the test cell described above. At 300 amp/ft 2 , the electrode potential is -0.28 V vs Hg/HgO and after continuous operation for 10,000 hours the electrode potentiual is -0.29 V, thereby demonstrating that the performance of a flooded air depolarized cathode can be restored utilizing the present invention, and moreover that such a restored electrode is greatly improved in useful lifetime as compared to the untreated electrode.
EXAMPLE V
A glass electrochemical cell was used, having two compartments separated by a medium porosity glass frit. Anodes (3 mm diameter×150 mm) consisted of preoxidized and mildly fluorinated (with SF 4 ) vitreous carbon rods, fluorinated to a level of about 5% fluorine by elemental analysis, or untreated rods were used as controls. The cathode was stainless steel. The anode side of the cell had provision for an argon gas inlet and a gas outlet. The inlet and outlet were of glass tubing with the inlet extending below the surface of the anolyte solution (100 ml), consisting of either sulfuric acid or tetrafluoroboric acid and the outlet dipping into an ozone indicating solution consisting of 0.2M aqueous potassium iodide (100 ml). Power was supplied to the cell by a Gates DC Power Supply. Current was measured by a Beckman 310 Multimeter. The charge was integrated with a Model 640 Digital Coulometer from The Electrosynthesis Co., E. Amherst, N.Y. Current efficiency for ozone generation was determined by iodometric titration of the ozone indicating solution using standard sodium thiosulfate solution as compared to the theoretical production of ozone according to the total charge passed.
Table 1 compares fluorinated vs unfluorinated vitreous carbon, various anolyte solutions, the role of current density, and temperature. The results in Table 1 demonstrate that the ozone current efficiency is significantly improved over the untreated anode material, when fluorinated vitreous carbon is used as the anode. Moreover, unfluorinated anodes (controls) are severely degraded in aqueous H 2 SO 4 solution, whereas fluorinated anodes under the same conditions survive intact, thereby clearly demonstrating the useful protection achieved by fluorination according to the methods of the present invention. The results also indicate that conc. aqueous HBF 4 is preferred as anolyte and that efficient cooling is required for optimal results.
TABLE 1__________________________________________________________________________Electrochemical Generation of OzoneExperiment Anode Anolyte Current Current Temp. Condition ofNo. Material Solution Density mA/cm.sup.2 Efficiency % °C. Anode__________________________________________________________________________1 Not fluorinated 5 --M H.sub.2 SO.sub.4 300 0.068 5 Degraded severely2 Fluorinated 5 --M H.sub.2 SO.sub.4 300 0.56 5 Intact, discolored3 Not fluorinated 48% HBF.sub.4 300 42 -15 No change4 Fluorinated 48% HBF.sub.4 300 49 -15 No change5 Not fluorinated 48% HBF.sub.4 500 5.4 10 Slightly degraded6 Fluorinated 48% HBF.sub.4 500 18 10 No change__________________________________________________________________________
EXAMPLE VI
The fluorination of two different carbon blacks, Cabot Co. Vulcan XC-72, and Anderson Development Co. Super AX-21 were compared. Vulcan XC-72 is commonly used in fuel cell electrodes and has a surface area (BET) of about 250 m 2 /g. Super AX-21 is more amorphous in character and has a very high surface area of about 3500 m 2 /g useful in absorbing a variety of toxic substances and is also distinguished by a high water content of about 65% by weight. Prior to fluorination each carbon was thoroughly dried in a dessicator over P 2 O 5 at 100° C. for 48 hours.
Following the fluorination procedure described in U.S. Pat. No. 3,340,081, the dried carbon (10 g) was placed in a 1 liter Parr Bomb, the apparatus evacuated, and about 100 g of sulfur tetrafluoride introduced. The reactor was then heated to 150° C. and was maintained at that temperature for 5.5 hours. On cooling to room temperature, the excess gas was vented, the reactor flushed several times with nitrogen and the fluorinated sample removed, washed well with water and dried.
A second set of samples (25 g) of Vulcan XC-72 and Super AX-21 were preoxidized to develop potential sites of instability, by magnetically stirring the carbon in 1 liter of 1M aqueous ammonium persulfate solution or in aqueous household bleach (5% active chlorine) for 24 hours at room temperature. The oxidized carbon was filtered, washed well with water and thoroughly dried in a dessicator over P 2 O 5 at 100° C. for 48 hours. Fluorination of 10 g samples was then conducted as described above.
The results of Table 2 demonstrate that preoxidation followed by fluorination according to the methods of the present invention greatly increases the fluorine content, compared to fluorination alone following the U.S. Pat. No. 3,340,081.
This significant increase in fluorine content is related to the greater level of surface oxides formed upon preoxidation. A measure of the quantity of some surface oxide groups may be obtained by titration with base. Table 2 shows the results of titration with aqueous NaOH, which provides the quantity of strong plus weaker acids. Titration with aqueous NaHCO 3 , identifies the level of stronger acids only. Strong acids are believed to be carboxylic groups whereas weaker acids are largely phenolic or enolic in nature. Thus the higher surface oxide levels achieved by preoxidation of carbons affords a higher level of specific fluorination of carbons because of the presence of more available sites for fluorination with a soft fluorinating agent.
TABLE 2______________________________________COMPARISON OF FLUORINATION AND SURFACEOXIDATION METHODS OF CARBONS VULCAN SUPER XC-72 AX-21______________________________________A: Fluorination Without preoxidation 2.5% F 3.0% F Preoxidized with (a) 1M (NH.sub.4).sub.2 S.sub.2 O.sub.8 6.6% F 9.6% F (b) NaOCl 9.4% F 10.5% FB. Surface Oxide Titrations Without preoxidation [NaOH], meq/g 0.40 0.29 [NaHCO.sub.3 ], meq/g 0.11 0.05 Preoxidized carbon (NH.sub.4).sub.2 S.sub.2 O.sub.8 [NaOH], meq/g 0.69 2.97 [NaHCO.sub.3 ], meq/g 0.15 1.43______________________________________
While the invention has been described in conjunction with specific examples thereof, this is illustrative only. Accordingly, many alternatives, modifications and variations will be apparent to persons skilled in the art in light of the foregoing description and it is therefore intended to embrace all such alternatives and modifications as to fall within the spirit and broad scope of the appended claims.
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Discontinuities, edge sites and grain boundaries in carbons, the primary locations of instabilities for oxidative corrosion and degradation, are prepared by preoxidation to form carbon-oxides followed by highly selective and relatively mild fluorination to specifically substitute carbon-oxygen functionality with stable carbon-fluorine groups. The novel fluorinated carbons have enhanced chemical and/or electrochemical stabilities to corrosion, improved hydrophobicity, lubricating properties, etc.
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FIELD OF THE INVENTION
This invention relates generally to electromagnetic compatibility (EMC), and more specifically to electromagnetic interference (EMI) suppression cores.
SUMMARY OF EMBODIMENTS OF THE INVENTION
An adjustable EMI suppression core comprises an outer core and an inner core. The outer core further comprises three horizontally aligned apertures. The inner core is rotatably engagable within the second aperture. The outer core has a first reluctance. The inner core comprises three sections. The first and third sections of the inner core have a second reluctance similar to that of the outer core. The second section of the inner core has a third reluctance much greater than the first and second reluctances.
The inner core may comprise a means of rotation with a tool adapter such as a key slot. A further embodiment of the adjustable EMI suppression core comprises threads on the exterior of the inner core and threads on the interior of the second aperture. Another embodiment of the adjustable EMI suppression core comprises a plastic case to enclose the outer core for protection.
Additional embodiments of the outer core comprise dividing the outer core into two portions. The two portions may be separated and later mechanically joined; for example, the two portions of the outer core may further comprise a hinge and a latch mechanism on opposite ends as a means of opening, closing, and locking the two outer core portions together. A separate embodiment comprises a latch mechanism at each end.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a three-dimensional view of an adjustable EMI suppression core. FIG. 1A shows the adjustable EMI suppression core comprised of an outer core, an inner core, a first aperture, a second aperture, and a third aperture. A first wire is shown inserted into the first aperture. A second wire is shown inserted into the third aperture.
FIG. 1B is a three-dimensional view of the inner core comprised of three sections and a means for rotating.
FIG. 2 is a three-dimensional view of the adjustable EMI suppression core divided into two portions attached at one end with a hinge and the other end fitted with a hook and latch mechanism.
FIG. 3 is a three-dimensional view of the inner core further comprising threads.
FIG. 4A is an end view of the adjustable EMI suppression core further comprising a plastic shell. FIG. 4A shows the inner core in Common Mode Position.
FIG. 4B is an end view of the adjustable EMI suppression core with the inner core in Normal Mode Position.
FIG. 5A is an end view of the adjustable EMI suppression core with the inner core in Common Mode Position and an exemplary common mode flux path.
FIG. 5B is an end view of the adjustable EMI suppression core with the inner core in Normal Mode Position and two exemplary normal mode flux paths.
FIG. 6 is a top cross-sectional view of the adjustable EMI suppression core. FIG. 6 shows an exemplary distance the inner core is rotatably engaged in the outer core.
FIG. 7A is an end view of the adjustable EMI suppression core with the height of the outer core reduced to less than the diameter of the inner core. The inner core is shown in the Common Mode Position and an exemplary common mode flux path is also displayed.
FIG. 7B is an end view of the adjustable EMI suppression core with the height of the outer core reduced to less than the diameter of the inner core. The inner core is shown in the Normal Mode Position and a set of exemplary normal mode flux paths is also displayed.
FIG. 8 shows a graph of increasing permeance in common mode and normal mode paths as the inner core becomes more deeply rotatably engaged within the outer core.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the following detailed description of embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.
Embodiments of the present invention provide for an apparatus for adjustable common mode/normal mode balance in emission suppression, shown completed in the figures.
When a signal travels through a conductor, a magnetic field is generated around that conductor. A ferrite core, having a relatively low reluctance, if placed around the conductor, can interact with this magnetic field. The magnetic field activates (permeates) the ferrite, which, in response to the magnetic field, imposes impedance that reduces a magnitude of EMI associated with the currents in wires passing through the ferrite core.
Referring to FIG. 1A and FIG. 1B , FIG. 1A shows a three dimensional view of an adjustable EMI suppression core 100 . Adjustable EMI suppression core 100 comprises an outer core 101 and an inner core 105 (shown in more detail in FIG. 1B ).
The outer core 101 has a first reluctance. The outer core 101 also has a first aperture 102 ; a second aperture 103 ; and a third aperture 104 . First aperture 102 , second aperture 103 , and third aperture 104 are arranged horizontally in sequence as shown in FIG. 1A . The first and third apertures are each suitable for a wire, shown as wire 106 and wire 107 , to pass through.
The diameters of aperture 102 and aperture 104 should be advantageously equal to the diameters of corresponding wire 106 and wire 107 . As the diameters of aperture 102 and aperture 104 get larger than the corresponding diameters of wire 106 and wire 107 , sensitivity to normal mode/common mode control decreases. One embodiment of this invention has the diameters of aperture 102 and aperture 104 equal to 105% of the diameters of corresponding wire 106 and wire 107 . A second embodiment has the diameters of aperture 102 and aperture 104 equal to 110% of the diameters of corresponding wire 106 and wire 107 . Additionally, aperture 102 and aperture 104 should be advantageously placed close to aperture 103 . As aperture 102 and aperture 104 are placed farther away from aperture 103 , control sensitivity of normal mode/common mode decreases. One embodiment of this invention has aperture 102 and aperture 104 at a distance from the nearest point of aperture 103 less than the diameters of apertures 102 and 104 .
FIG. 1B shows a three dimensional view of inner core 105 . Inner core 105 comprises a first section 105 A having a second reluctance; a second section 105 B having a third reluctance; and a third section 105 C having the second reluctance. Sections 105 A, 105 B, and 105 C are also shown in FIG. 1A . The shape of inner core 105 is generally cylindrical. Exemplary shapes of sections 105 A, 105 B, and 105 C are shown in FIG. 1A . Deviations from the depicted shapes of sections 105 A, 105 B, and 105 C are contemplated. For example, whereas the shapes of sections 105 A and 105 C are shown to be curved on boundaries 109 and 110 ( FIG. 1B ) with section 105 B, the boundaries 109 and 110 could be straight or less convex than shown and still be within the scope and spirit of the invention.
The inner core 105 is rotatably engagable in the second aperture 103 of the outer core 101 . Tool adapter 108 , shown in FIGS. 1A and 1B , allows for insertion of a tool, such as a screwdriver blade, for rotation of inner core 105 .
Inner core sections 105 A and 105 C have a second reluctance similar to the reluctance of the outer core 101 . Inner core section 105 B has a third reluctance. The second reluctance of inner core sections 105 A and 105 C may for example be less than or equal to twice the first reluctance of outer core 101 . The greater the second reluctance is relative to the first reluctance, the common mode/normal mode control sensitivity decreases. In an embodiment the second reluctance is equal to or less than the first reluctance. Additionally, the third reluctance of inner core section 105 B may for example be at least five times greater than the first and the second reluctance. The closer the third reluctance is relative to the first and second reluctance, the common mode/normal mode control sensitivity decreases.
FIG. 2 shows a three-dimensional view of an embodiment of adjustable EMI suppression core 100 wherein outer core 101 is separable into two parts to facilitate insertion of wires 106 and 107 . In this embodiment, outer core 101 is comprised of two parts, 101 A and 101 B. Aperture 102 of FIG. 1 is shown as aperture portions 102 A and 102 B in FIG. 2 . Aperture 103 of FIG. 1 is shown as aperture portions 103 A and 103 B in FIG. 2 . Aperture 104 of FIG. 1 is shown as aperture portions 104 A and 104 B in FIG. 2 .
The embodiment of the adjustable EMI suppression core in FIG. 2 comprises the hinging of outer core part 101 A to outer core part 101 B with hinge 204 as shown in FIG. 2 . This allows the outer core 101 to open and outer core parts 101 A and 101 B to separate. The separation of outer core parts 101 A and 101 B allows for wires 106 and 107 to be placed in aperture portions 102 A and 104 A followed by the closing of outer core parts 101 A and 101 B. Also, the separation of outer core parts 101 A and 101 B allows for the inner core 105 to be placed in either aperture portion 103 A or 103 B followed by the closing of outer core parts 101 A and 101 B.
The embodiment in FIG. 2 further comprises the ability to lock outer core part 101 A to outer core part 101 B with lock 203 at the opposite end of outer core 101 from hinge 204 . An example embodiment of lock 203 comprises a hook 203 B and a pin 203 A. Hook 203 B goes around pin 203 A and locks outer core part 101 A to outer core part 101 B to prevent them from separating. Unhooking hook 203 B from around pin 203 A unlocks outer core part 101 A from outer core part 101 B and allows them to separate. Whereas a hook and a pin are shown as an exemplary means to maintain the assembly, any suitable securing means may be used to maintain the assembly.
In an alternative embodiment not shown, a lock such as lock 203 above is used on each end of outer core 101 removing the requirement for hinge 204 .
FIG. 3 shows a further embodiment of inner core 105 comprising the addition of threads 301 . Matching threads are formed along the inside of aperture 103 . Threads 301 enable inner core 105 to be rotatably engaged in aperture 103 of outer core 101 . This embodiment allows control of how deeply inner core 105 is engaged within aperture 103 of outer core 101 .
FIG. 4A and FIG. 4B portray end views of adjustable EMI suppression core 100 . Outer core 101 is shown with the two halves, 101 A and 101 B, closed. The entire adjustable EMI suppression core 100 further comprises a plastic case 406 to enclose outer core 101 . Typically, the material of which outer core 101 is composed is brittle. Common examples of core materials include Material 43 or Material 61 from Fair-Rite Products Corporation, P.O. Box J, One Commercial Row, Wallkill, N.Y. 12589-0288. Thus, plastic case 406 contains and protects outer core 101 in adjustable EMI suppression core 100 . An embodiment comprising plastic case 406 removes the need for hinge 204 ( FIG. 2 ) and lock 203 ( FIG. 2 ).
In FIGS. 4A and 4B , rotation vector 401 is not a physical embodiment. Rotation vector 401 represents the degrees of turn of inner core 105 with respect to axis 402 , also a non-physical embodiment. FIG. 4A shows inner core 105 rotated zero degrees with respect to axis 402 . This position of inner core 105 is known as “Common Mode Position”. FIG. 4B shows inner core 105 rotated ninety degrees with respect to axis 402 . This position of inner core 105 is known as “Normal Mode Position”.
Outer core 101 comprises a top surface 403 and a bottom surface 404 . Outer core 101 has a height H 405 between top surface 403 and bottom surface 404 .
FIG. 5A and FIG. 5B show the respective end views from FIG. 4A and FIG. 4B of adjustable EMI suppression core 100 . The Common Mode Position shown in FIG. 5A shows an exemplary common mode flux line 501 which passes through the relatively low reluctance paths provided by inner core sections 105 A and 105 C. The Normal Mode Position shown in FIG. 5B shows exemplary normal mode flux lines 502 A and 502 B which pass through the relatively low reluctance paths provided by inner core sections 105 A and 105 C. As explained earlier, control sensitivity of common mode and normal mode increases as apertures 102 and 104 are made closer to aperture 103 . Additionally, control sensitivity increases as height H 405 becomes closer to, or even less than, a diameter of aperture 103 .
As shown in FIG. 5A , if a common mode current flows through wires 106 and 107 , a relatively low reluctance path around both wires as shown as flux path 501 provides EMI suppression of the common mode currents.
As shown in FIG. 5B , if a normal mode current flows through wires 106 and/or 107 , a relatively low reluctance path around each wire as shown as flux paths 502 A and 502 B provides EMI suppression of the normal mode currents.
A top-view cross-section of adjustable EMI suppression core 100 is shown in FIG. 6 . A length L 604 of the outer core 101 is shown. An empty distance M 606 remaining in aperture 103 from inner core 105 is also shown. A distance D 605 within aperture 103 that contains inner core 105 is represented by distance L 604 minus distance M 606 .
FIGS. 7A and 7B show an end view of adjustable EMI suppression core 100 wherein outer core 101 has a shorter height than depicted in FIGS. 4A and 4B . The height of inner core sections 105 A and 105 C shown as I 704 . The Common Mode Position is shown in FIG. 7A . The Normal Mode Position is shown in FIG. 7B . In these two figures outer core 101 comprises two pieces, 701 A and 701 B. The height H 705 of outer core 101 in this embodiment equals I 704 . When H 705 equals I 704 , there is no low reluctance material in outer core 101 for flux paths to go around both wires 106 and 107 in the Normal Mode Position thereby providing very small common mode EMI suppression. The relative position of the normal mode flux paths 703 A and 703 B are shown in FIG. 7B . There will be common mode flux paths through the air outside of the adjustable EMI suppression core 100 but they are small because air has high reluctance compared to the first and second reluctances.
In FIG. 7A , the distance J 706 between the ends of inner core section 105 A and inner core section 105 C is shown. In the Common Mode Position of FIG. 7A , for common mode flux paths 702 to pass through the lower reluctance material in the inner core section 105 A and 105 C, J 706 needs to be less than H 705 .
FIG. 8 shows a graph 800 of permeance versus distance D 605 ( FIG. 6 ) into outer core 101 versus degree of turn in radians of inner core 105 . Permeance is the inverse of reluctance. Line 801 represents the permeance in normal mode. Line 802 represents the permeance in common mode. Line 801 representing normal mode permeance and line 802 representing common mode permeance are ninety degrees out of phase and increase in amplitude as inner core 105 is further inserted into aperture 103 . Trend line 803 shows the increase in permeance with increasing degrees of turn. The slope of trend line 803 is dependant on the pitch of threads 301 ( FIG. 3 ). It should be understood that at zero turns there is non-zero common mode permeance and non-zero normal mode permeance. There will always be a non-zero amount of normal mode permeance within the outer core material around wire 106 and wire 107 . There will always be a non-zero amount of common mode permeance around both wires 106 and 107 . As normal mode permeance and common mode permeance increase, it is relative to when inner core 105 is not inserted into aperture 103 , i.e. zero turns. Axis 804 represents the ratio of distance D 605 divided by length L 604 . Axis 805 represents the ratio of permeance versus the maximum permeance achievable when inner core 105 is fully engaged in aperture 103 , i.e. when distance D 605 divided by length L 604 equals 1. Axis 806 represents the amount of rotation of inner core 105 in radians. The number of turns for D to equal L is dependant on the pitch of threads 301 ( FIG. 3 ).
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An adjustable EMI suppression core has an outer core having a first reluctance. The outer core has three apertures aligned horizontally. A first aperture and a third aperture are each suitable for a wire to be placed therein. A second aperture is located between the first and third apertures. An inner core is rotatable engaged in the second aperture, for example, using matching threads on an inner surface of the second aperture and an outer surface on the inner core. The inner core has first and third portions having a second reluctance similar to the first reluctance and a third portion having a reluctance considerably higher than the first and second reluctances. Rotating the inner core varies a normal mode and a common mode suppression of currents in the wires placed in the first and second apertures.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to film forming polymer compositions and their use with sheets of inkjet printing paper. Inkjet printing is a non-impact digital printing technology. Unlike laser, dry toner, offset, and other forms of contact printing, non-impact printing uses liquid ink. There are two primary types of inkjet printing technology, continuous and drop-on-demand. Both types of inkjet printing involve a pool of liquid ink that is broken up into individual droplets by high frequency vibration when it leaves the nozzle. This technology enables inkjet printing to achieve higher printing speeds than toner printing.
[0004] Drop-on-demand inkjet printing devices generate ink droplets when needed using a thermal (bubble) mechanism or piezoelectric technique. Continuous ink jet printers utilize electrostatic charging devices to continuously supply an ink stream at high velocity to the nozzles during printing. These electrostatic charging devices break the ink fluid into individual ink droplets, which are directed towards the paper substrate or towards an ink-capturing device. Both drop-on-demand and continuous inkjet printing technologies have broad applications such as printing devices for home and office, bar code applications, and industrial printing uses.
[0005] The liquid ink of inkjet devices has three basic components: a solvent, a colorant, and a humectant. The humectant is a nonvolatile cosolvent (such as glycerin or ethylene glycol), which absorbs water from the air and keeps the nozzle moist and clog free. The colorant is either a dye or a pigment. Dyes are soluble in the solvent, have a uniform homogenous phase, and easily pass through the nozzle. Pigments are non-soluble particles, must be adequately dispersed by the solvent, and can dry out and form aggregates which clog inkjet nozzles. Water is a common solvent because it has a low viscosity, high surface tension, dissolves dyes, and is a good dispersion medium for pigments. Aqueous inkjet inks therefore are more environmentally friendly, less toxic, and are non-combustible.
[0006] Unfortunately, printing with aqueous inkjet inks and especially dye-based inks have some disadvantages. Aqueous inkjet inks adhere less strongly to paper substrates and as a result they are more sensitive to surface friction forces, react with light and detach from the paper substrate, and are prone to feathering. In addition because they are water soluble, dye-based aqueous inkjet inks also diffuse in humidity when wetted. As a result, when these inks are printed on high stress surfaces that undergo numerous environmental changes the printing may get smeared. Some examples of these sorts of high stress surfaces are promotion documents, transaction bills, and addresses on envelopes. One attempt at addressing this disadvantage is described in U.S. Pat. No. 6,824,840 which describes a hydrophobic cationic dispersion polymer layer applied to the surface of the printer paper which enhances print density, detail, color depth and vibrancy, and drying. Another attempt is described in U.S. Pat. No. 6,764,726.
[0007] A need remains however for inkjet receiving sheets suitable for use with aqueous-based inks. There is a need for inkjet receiving sheets to have improved image stability with good ink adhesion during wet rubbing. Further, there is a need for receiver sheets that enable prints with improved optical density. In addition, there is also a need for receiver sheets with high degree of waterfastness. The need also exists for inkjet receiving sheets with good bleed resistance. Finally, there is a need for inkjet receiving sheets with good sheet property such as feel and touch before and after printing.
BRIEF SUMMARY OF THE INVENTION
[0008] At least one embodiment of the invention is directed towards an ink jet recording sheet having a solid substrate and a composition coating the solid substrate. The composition comprises at least one cationic polymer. The composition can also comprise a second non-ionic polymer. The composition also comprises one item selected from the list consisting of starch, inorganic salt, pigment, water, and any combination thereof, or all of the items from the list. The substrate can be selected from the list consisting of cellulose, furnish, wet web, web paper, paper, or sheets of paper. These substrates can be treated, untreated, wood free, and wood containing substrates. The composition can be applied to the substrate when it is being smoothed out by a size press machine, a calendaring machine, a coating machine, a dryer section, or by any other machine commonly used in the papermaking process.
[0009] At least one embodiment of the invention is directed to an ink jet recording sheet in which at least one of the polymers has a reduced specific viscosity which is no greater than 30 dL/g and/or in which the non-ionic polymer is a polyvinyl alcohol with a hydrolysis level above 85%. The cationic polymer and the non-ionic polymer can together comprise between 2% and 35% by mass of the composition coating. The molar ratio of cationic polymer to non-ionic polymer can be 1:1. At least one of the polymers can be a copolymer. The cationic polymer can be an acrylamide-dimethylaminoethylacrylate benzyl chloride quaternary salt dispersion polymer/acrylamide copolymer. The non-ionic polymer can be a pigment dispersion polymer.
[0010] At least one embodiment of the invention is directed to an ink jet recording sheet in which the starch is one item selected from the list consisting of an ethylated starch and a cationic starch. The inorganic salt can be water-soluble and can have a charge that is at least a divalent charge, such as magnesium sulfate and calcium chloride. The pigment can be one item selected from the list consisting of: titanium oxide, aluminum oxide, clay, silica, and calcium carbonate. The recording sheet can be stored in a humidity and temperature controlled room for at least 12 hours before printing.
[0011] At least one embodiment of the invention is directed to an ink jet recording sheet having a coating composition in which the mass of the coating composition is 1-3% non-ionic polymer, 1-2% cationic polymer, 3-5% starch, 0.5-2% pigment, 0.5-2% salt, and 80% to 94% water. At least one embodiment of the invention is directed to an ink jet recording sheet in which the mass of the coating composition is 1.8% cationic polymer, 1.5% polyvinyl alcohol polymer, 3.9% cationic starch, 0.8% calcium chloride, and 92% water.
[0012] At least one embodiment of the invention is directed to a method of increasing the inkjet ink adhesive properties of paper including the steps of: providing a solid substrate for making paper, providing a coating composition, and coating the solid substrate with the coating composition with a papermaking device. The coating composition comprises at least one cationic polymer, at least one non-ionic polymer, and one item selected from the list consisting of starch, inorganic salt, pigment, water, and any combination thereof.
[0013] A least one embodiment further comprises the step of preparing the coating composition. The preparation includes the steps of: providing at least one cationic polymer, providing at least one non-ionic polymer, providing at least one item selected from the list consisting of starch, inorganic salt, pigment, water, and any combination thereof, combining the at least one cationic polymer, the at least one non-ionic polymer, and the one item selected from the list consisting of starch, inorganic salt, pigment, water, and any combination thereof, and adding the non-ionic polymer after adding the cationic polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an illustration of a papermaking process during which a substrate is treated with the composition.
[0015] FIG. 2A is an illustration of a water removal section of FIG. 1 .
[0016] FIG. 2B is an illustration of a size press section and dryer section of FIG. 1 .
[0017] FIG. 2C is an illustration of a water removal section of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0018] For purposes of this application the definition of these terms is as follows:
[0019] “Substrate” means a sheet of paper or a sheet of paper precursor that can be or has been treated by the inventive composition.
[0020] “Pulp” means the fibrous raw materials used to make paper, the fibrous raw materials are usually of vegetable origin, are commonly cellulose fibers, are commonly wood based, but may be synthetic or of other origin, and may contain pieces of wood.
[0021] “Furnish” means a sheet of paper precursor that comprises pulp and water and is approximately 5% or less solid matter.
[0022] “Wet Web” means a sheet of paper precursor that results from the processing of Furnish through a Water Removal Section.
[0023] “Web Paper” means a sheet of paper precursor that results from processing Wet Web by at least one Dryer Section.
[0024] “Paper” means a sheet of paper precursor that results from processing Web Paper by a Calendaring Section.
[0025] “Sheet of Paper” means Paper that has been cut into one or more useful shapes and/or sizes.
[0026] “Printer Paper” and “Inkjet Recording Sheet” means Paper or a Sheet of Paper suitable for use with a printer.
[0027] “Colorant” means a composition of matter that is deposited on a sheet of paper, adheres to the sheet of paper, and in most cases is a visibly different color than the sheet of paper.
[0028] As used in this definition, “color” includes the full chromatic spectrum as well as black, white, and every shade of grey. Colorants can be dyes and pigments.
[0029] “Dispersion” means a plurality of particles dispersed in a liquid medium to facilitate its transfer.
[0030] “Solvent” means a liquid medium used to facilitate transfer of particles, the particles may or may not be dissolved in the liquid medium.
[0031] “Water Fastness” means a measurement of how well printed ink remains attached to a sheet of paper when subjected to water.
[0032] “Light Fastness” means a measurement of how well printed ink remains attached to a sheet of paper when subjected to light.
[0033] “Feathering” is the tendency of printed ink to spread along the pores, fibrous channels, and irregularities on a paper substrate instead of adhering to the point of impact where a printer deposited it.
[0034] “Bleeding” is the tendency of printed ink to change color as a result of a first mass of printed ink feathering into a second mass of printed ink of another color.
[0035] Referring now to FIGS. 1 , 2 A, 2 B, and 2 C there is shown at least one mechanism for the process of papermaking. The papermaking process (1) involves the processing of paper raw materials by a Water Removal Section (2), a Coating/Press Section (3), at least one Dryer Section (4), a Size Press Section (5), and a Calendar Section (6). A person of ordinary skill in the art will recognize that these various sections can be arranged in different orders, in greater or lesser numbers, and in combination with additional components or sections than those presented in these FIGs. A substrate of sheet of paper precursors in the papermaking process can be treated by a film forming polymer composition in the: Coating/Press Section (3), Size Press Section (5), Calendar Section (6), and/or during an additional or subsequent coating process.
[0036] In at least one embodiment of the invention a film forming polymer composition containing cationic polymers and other components together improve the properties of inkjet printer paper. In at least one embodiment the film forming polymer composition also comprises at least one non-ionic polymer. In at least one embodiment the film forming polymer composition is comprised of at least one cationic polymer and one or more components such as starch, polyvinyl alcohol, inorganic salt, pigments and water. The film forming polymer composition improves ink adhesion both for dye based and pigment based inkjet inks.
[0037] In the case of dye based inkjet inks, the anionic dyes bind tightly to the cationic polymers of the composition. In the case of pigment based inkjet inks, the cationic polymers of the composition bind the negatively charged portions of the pigment and the non-ionic polymer portions of the composition bind other portions of the pigment molecules. As a result, the composition more tightly binds inkjet inks and provides printed on sheets of paper greater light fastness, greater water fastness, and more resistance to rubbing out when wet, fading when wet, bleeding, and feathering. This improves overall paper handling.
[0038] In at least one embodiment of the invention the substrate for this invention is untreated wet web, web paper, paper, or a sheet of paper. The film forming polymer composition can be applied on a size press machine, a calendaring machine, and/or a paper coater as a surface treatment on the paper substrate (for example untreated wood-free substrate). Examples of papermaking machines are described in U.S. Pat. Nos. 4,565,155 and 4,413,586. The film forming polymer composition can be applied on the substrate by a wire-wound rod coater or by any other manner known in the art.
[0039] The film forming polymer composition can be prepared by cooking an aqueous starch solution using a steam cooker at 10 to 15% wt concentration, then adding the cationic polymer to the starch solution with mixing, then adding polyvinyl alcohol solution to the mixture with mixing, then adding the salt solution, then finally adding a pigment to the film forming polymer composition. The pigment may be added to the film forming polymer composition as a dispersion or in powder form. Water can be added before or after the cationic polymer addition to adjust to the desired % solids.
[0040] The cationic polymers of this invention with an RSV (Reduced Specific Viscosity) of 0.1 to 30 dL/g can be prepared by solution, gel, dry, dispersion, suspension and emulsion polymerization. In at least one embodiment the polymer is a cationic dispersion polymer with RSV of less than 10 due ease of transfer through pipes or pumps and mixing. Film forming polymer compositions can readily be made using low RSV cationic dispersion polymer due to ease of mixing. The cationic dispersion polymers of this invention have from 20 to 80 mole percent of cationic monomer.
[0041] The non-ionic polymer with RSV 0.1 to 30 dL/g can be prepared by solution, gel, dry, dispersion, suspension and emulsion polymerization. In at least one embodiment the polymer of this film forming polymer composition is polyvinyl alcohol with hydrolysis levels above 85%. A polyvinyl alcohol used in an example film forming polymer composition has a hydrolysis level of 99%.
[0042] In at least one embodiment the starches of this invention are those typically used in papermaking machines such as cationic modified and/or ethylated starch. Examples of the starches are Penford Gum 280 (an ethylated starch, by Penford Corp. of Centennial, Colo.) and Cerestar HS05972.
[0043] In at least one embodiment inorganic water-soluble salts with cations having divalent or higher charges are selected for use in the film forming polymer composition.
[0044] In at least one embodiment a component in the film forming composition includes a pigment. One of the selected pigments is calcium carbonate. A dispersion of calcium carbonate is preferred for ease of mixing into the film forming composition.
[0045] In at least one embodiment, after the substrate has been treated with the film forming composition, it is dried by passing the substrate through a dryer or other drying type equipment. The drying process facilitates smoothing out of the treated substrate. In at least one embodiment, the treated substrate is stored in a humidity and temperature controlled room for at least 12 hours before being printing on. Tests run on a Versamark continuous inkjet printing device (by Kodak Corp. of Rochester, N.Y.) have confirmed this.
[0046] The foregoing may be better understood by reference to the following examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention.
EXAMPLE 1
Preparation of Cationic Dispersion Polymer
[0047] A 27% polymer solids, 50150 mole percent acrylamide/dimethylaminoethylacrylate benzyl chloride quaternary salt dispersion copolymer was prepared as follows:
[0048] A low viscosity model 1.5 liter reaction flask was fitted with a mechanical stirrer, baffle, thermocouple, condenser, nitrogen purge tube, an addition port and heating tape. To a 2 liter beaker were added 311.58 g de-ionized water, 23.08 g polyDADMAC (15% aqueous solution, Nalco), 58.46 g of polydimethylaminoethylacrylate methyl chloride quaternary salt (15% aqueous solution, Nalco), 153.85 g of ammonium sulfate, 19.23 g sodium sulfate, 9.23 g glycerin, 11.54 g adipic acid, 2.31 g sodium hypophosphite, 114.276 g of acrylamide (49.39% aqueous solution), 0.31 g of ethylenediaminetetraacetic acid, tetra sodium salt, and 281.92 g of dimethylaminoethylacrylate benzyl chloride quaternary salt (75.76% aqueous solution). The mixture was added to the reaction flask and heated to 48° C. while stirring at 700 rpm. After reaching 48° C., 1.15 g of a 1.0% aqueous solution of 2,2′-azobis(2-amidinopropane) dihydrochloride (Wako V-50, Wako Chemicals, Dallas, Tex.) was added to the reaction mixture and a constant purge of nitrogen was started. After one hour, 2.31 g of a 1% aqueous solution of 2,2′-azobis(2-amidinopropane) dihydrochloride was added. After an additional four hours, 3.08 g of a 10.0% aqueous solution of 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VA-044, Wako Chemicals, Dallas, Tex.) was added. After two hours the reaction is cooled, and 7.69 g acetic acid was added.
[0049] The final product was a smooth, milky, white dispersion with a bulk viscosity of 200 to 800 cps and a reduced specific viscosity of 0.2-0.9 dl/g, measured for a 0.045% solution of the polymer in 0.125N aqueous sodium nitrate at 30° C.
Preparation of Film Forming Composition
[0050] The lab scale coating formulations were prepared as follows:
[0051] The starch was placed into a steam cooker and cooked. Water was added to the starch mixture based on the formulation calculation to have solids % suitable for coating or size press applications. Then the cationic dispersion polymer was added to the batch with mixing. Polyvinyl alcohol solution was then added to the batch under mixing to prevent precipitation. Pre-made salt solution was added under mixing. Calcium carbonate dispersion was then added under mixing.
[0052] Film forming composition application:
[0053] The coating was applied onto the substrate, which was a wood free paper with size of about 8.5″ by 12″ and basis weight of about 90 gsm. The substrate sheet was fixed on the surface of a drawdown glass plate. And the coating liquid was applied onto paper substrate with a #9 drawdown rod. The treated substrate was then dried by passing through a drum dryer at 170 to 210 degree F. with the treated side facing the stainless steel drum surface. The other side was then treated and dried again in order to minimize paper curling for printing.
FORMULATION EXAMPLES
[0054]
[0000]
TABLE 1
Representative Film forming Formulations
Example 1
Example 2
Example 3
Cationic dispersion
1.8
2.5
2.8
polymer
Cationic Starch
3.9
4.2
3.5
Polyvinyl alcohol
1.5
1.7
1.2
Calcium Chloride
0.8
0
0
Magnesium Sulfate
0
0.6
0
Calcium carbonate
0
0
1.5
Water
92
91
91
[0055] The cationic dispersion polymer used in the example formulas was a 50/50 mole % acrylamide-co-DMAEA.BCQ copolymer with RSV equal to 0.5 synthesized by Nalco Company.
[0056] The cationic starch was CereStar HS05972 from Cerestar, Netherlands. Polyvinyl alcohol was from Celanese with trade name Celvol 125 or the solution form Celvol 08125.
[0057] Calcium chloride was purchased from VWR.
[0058] Magnesium sulfate was purchased from VWR.
[0059] Calcium carbonate was a dispersion product with the trade name JetSet from J. M. Huber at Atlanta, Ga.
[0060] The print quality being evaluated included ink density, water fastness, bleed % and ink wet rub %. Water fastness was expressed as the percentage of color density change for the printed ink at the maximum inking level. The ink density is a measurement of the degree of light reflection from the surface area of interest. The higher the ink density, the better the print image. For example, Kodak Versamark continuous inkjet printing desires waterfastness equal or higher than 99%.
[0061] The bleed % is the indication of print ink migrating into neighboring areas when the print target is soaked in water. Therefore, the quantitative expression of bleed % is the subtraction of ink density near soaked area from the optical density of paper substrate divided by the ink density before soaking×100. The desired bleed % by Kodak Versamark is less than 10% Wet ink adhesion or wet rub test determines how well the ink sustains the rub friction under wet conditions. The wet ink adhesion test was conducted by adding three drops of D.I. water onto the printed solid ink area thereafter, a 100 gram weight was placed on the water, then the ink area was rubbed toward the unprinted paper surface 10 times (back and forth). The wet rub % is expressed as {[(the ink density of the rubbed area near the print target)−(ink density of paper)]/Ink density of the print target before wet rub test}×100. The desired ink wet adhesion % by Kodak Versamark is less than 10%.
PRINTING EXAMPLES
[0062] The printing test was done on HP DeskJet 6122 inkjet printer using Process Black from Collins Ink.
[0000]
TABLE 2
Inkjet Print Data for Printed Sheets
Waterfastness
Sheet example
Ink Density
%
Bleed %
Wet Rub %
Example 1
1.13
109
0
0.9
Example 2
1.13
110
0.9
0.9
Example 3*
1.09
109
0.9
1.8
Reference 1
1.11
114
3
35
Reference 2
1.10
105
13
52
Reference 3*
1.07
104
0.0
0.9
Reference 1 was the commercial inkjet paper ImageGrip manufactured by International Paper.
Reference 2 was the commercial inkjet paper HP Advanced made by Hewlett Packard.
Reference 3 was the commercial inkjet paper Z Plot 650 manufactured by Ziegler.
*indicates that the printer paper was printed with ink lot number FY2003 manufactured by Collins Ink. The other examples were printed with ink lot number FV2003 manufactured by Collins Ink.
[0063] The data shown in Table 2 demonstrate that good print quality can be obtained using paper treated with the representative film forming formulations described in this invention.
[0064] Changes can be made in the composition, operation, and arrangement of the method of the invention described herein without departing from the concept and scope of the invention as defined in the claims. While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein. All patents, patent applications, and other cited materials mentioned anywhere in this application are hereby incorporated by reference in their entirety.
[0065] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0066] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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The invention provides an ink jet recording sheet which is highly resistant to printings smearing, running, feathering, color bleeding, or fading when wet, humid, or exposed to intense or continual light. The recording sheet has a solid substrate and a composition coating the solid substrate. The composition comprises a cationic polymer as well as starch, inorganic salt, pigment, and water. The composition can further comprise a non-ionic polymer. The coating tightly binds both pigment based inkjet inks and dye based inkjet inks. The composition is easy to apply and the ink jet recording sheet can be easily formed with a standard size press device.
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[0001] This application is a continuation of U.S. application Ser. No. 10/144,452, filed in the United States on May 10, 2002, which claims priority to German Patent Application No. 101 23 230.6 having a filing date of May 12, 2001.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a diffractive optical element and also an optical arrangement comprising a diffractive optical element.
[0003] A diffractive optical element is disclosed in the specialist paper “Zonal diffraction efficiencies and imaging of micro-Fresnel lenses” in J. Mod. Opt., 45, 1405, 1998. The latter proposes reducing the structural heights of the diffraction structures with increasing radius of the Fresnel lenses therein, that is to say with decreasing structural width, and this, in the case of the optical boundary conditions chosen therein, results in an increase in the diffraction efficiency at the lens rim.
[0004] In the case of many diffractive optical elements in which, as is still being discussed, the diffraction efficiency decreases with smaller structural width, such a variation in the structural height does not, however, result in an improvement in the diffraction efficiency, with the result that the teaching of the specialist paper cannot be generalized. A diffractive optical element having constant structural heights is disclosed in U.S. Pat. No. 5,623,365 A. One of the transmissive diffractive optical elements described therein has the function of a lens having a certain focal length. This necessitates that the widths of the diffraction structures become smaller with increasing distance from the central point. The greater the desired refracting power of such a diffractive optical element with a given refractive index is to be, the greater becomes the variation in the widths of the diffractive structures with the distance from the central point and, consequently, the variation in the ratio of said widths and of the wavelength, which ratio is mainly responsible for the achievable local diffraction efficiency.
[0005] In the case of a diffractive optical element according to the type of U.S. Pat. No. 5,623,365 A, said variation in the ratio of structural width and wavelength manifests itself, as calculations based on the electromagnetic diffraction theory have shown, in that the more light is diffracted into other orders of diffraction, the narrower are the diffraction structures. This results in losses in the local diffraction efficiency in the region of narrower diffraction structures, and this results in a variation, usually undesirable, in the local diffraction efficiency of the diffractive optical element.
[0006] EP 0 312 341 A2 describes a transmissive diffractive optical element that has a plurality of concentrically disposed diffraction regions that are each designed for different illumination wavelengths and within which there is a constant structural height. Within each of said diffraction regions, therefore, the disadvantages explained in connection with U.S. Pat. No. 5,623,365 A also occur here in the case of a variation of the structural widths, and this affects the dependence of the local diffraction efficiency.
[0007] The diffractive optical element in EP 0 312 341 A2 may, in addition, have annular zones that are of opaque or partially transparent design in order to modify the light passing through so as to achieve a desired intensity distribution in the beam path downstream of the diffractive optical element. EP 0 312 341 A2 consequently discloses an optical arrangement wherein the constant structural heights of the diffraction structures for an illumination wavelength also result in the disadvantages that were discussed in connection with U.S. Pat. No. 5,623,365 A.
[0008] It is therefore a first object of the present invention to develop a diffractive optical element in such a way that its local diffraction efficiency is optimally adapted to the application purpose.
[0009] Said object is achieved, according to the invention, by a diffractive optical element having the features of the present invention.
SUMMARY OF THE INVENTION
[0010] Diffractive optical elements are used, for example, to correct for certain aberrations in an optical arrangement, for example the longitudinal color aberration, the color magnification error, the secondary spectrum and also the color variation in the coma. In addition, monochromatic aberrations may also be corrected.
[0011] The invention is based on the insight that the height of the diffraction structures can be used as a degree of freedom to modify the local diffraction efficiency of the diffractive optical element and can be altered over the area of the diffractive optical element. At the same time, it was recognized that the teaching of the specialist paper relating to reducing the structural heights so as to increase the diffraction efficiencies of less wide diffraction structures is achieved only in the case of special optical boundary conditions in which an improvement in the blaze effect is achieved by reducing the structural heights and actually results in an increase in the diffraction efficiency. In most other cases, in which the blaze effect is not improved in this way by the structural height change, the teaching of the specialist paper achieves precisely the opposite of the desired effect, namely a reduction in the diffraction efficiency at those points at which it should actually be increased according to the specialist paper, namely in the region of low diffraction structures.
[0012] The diffractive optical element according to the invention increases the comparatively low diffraction losses in the region of the wide structures and, thus, matches them to the comparatively large diffraction losses in the region of the less wide structures in such a way that a diffractive optical element results that has a local diffraction efficiency remaining constant over its area, and this is desirable for many application cases. In addition, required patterns of local diffraction efficiencies can be achieved by means of the structural height variation without substantial impairments having to be accepted in other imaging properties of the diffractive optical element in the process.
[0013] Because of the structural height variation in the region of the less wide diffraction structures, the diffractive optical element according to the invention has lower efficiency losses due to structural height than in the region of the wider diffraction structures. This is utilized to compensate completely or partly or even to overcompensate for the magnitude of the diffraction efficiency due to structural width in the region of the less wide diffraction structures that inevitably occur in the case of diffractive optical elements having constant structural height. In the case of overcompensation, the diffractive optical element has the highest diffraction efficiency at those points where, normally, the diffraction efficiency is lowest, namely in the region of the diffraction structures having the smallest widths.
[0014] In a preferred embodiment of the invention, a diffractive optical element in accordance with claim 2 has the constant pattern, particularly desired for many application cases, of the diffraction efficiency function over the area of the diffractive optical element. Said pattern is achieved by compensating exactly for the increase in the diffraction efficiency in the case of larger structural widths by a corresponding reduction in the structural height in the region of wide diffraction structures. In this connection, preferably proceeding from an optimum structural height for the diffraction structure, for which known calculating formulae exist, the structural height is reduced.
[0015] The diffractive optical element in accordance with Claim 3 makes it possible to fulfill, for example, requirements relating to the diffraction efficiency function of the diffractive optical element, in which the diffraction efficiency function should increase towards the rim of the diffractive optical element. Such a diffractive optical element is able, for example, to compensate for a radially oppositely directed diffraction efficiency decrease of other optical components.
[0016] The diffractive optical element in accordance with Claim 4 may be used as an apodization element.
[0017] A diffractive optical element in accordance with Claim 5 can be produced with acceptable cost and is not very alignment-critical because of its rotational symmetry.
[0018] The diffraction efficiency is increased in the case of a diffractive optical element in accordance with Claim 6 .
[0019] The diffractive optical element can be designed as a transmissive diffractive optical element in accordance with Claim 7 or as a reflective optical element, depending on application purpose.
[0020] A further object of the present invention is to develop an optical arrangement comprising a diffractive optical element according to the preamble of Claim 9 in such a way that its flexibility is increased yet again if the required local total efficiencies are implemented for the optical arrangement.
[0021] This object is achieved, according to the invention, by an optical arrangement having the features of Claim 9 .
[0022] An additional neutral filter makes it possible to implement, for example, fine adjustments to achieve a required total efficiency function. The local total efficiency of the optical arrangement is made up in this connection of the local diffraction efficiency of the diffractive optical element and, optionally, further diffractive optical components and the local transmission of the neutral filter and, optionally, of further optical components. The transmission function of the neutral filter may, in this connection, be stepless, i.e. have a continuous transmission pattern or, alternatively, be graded, i.e. have discrete changes in the transmission.
[0023] Since neutral filters are, as a rule, less critical in the alignment of an optical arrangement, an optical arrangement can be realized in which a plurality of neutral filter shaving various transmission functions can be substituted for one another in order, in this way, to achieve different required total efficiency functions. Desired local effects that could be achieved only at higher cost by means of the variation in the structural height of the diffractive optical element can also be produced in such an optical arrangement with the aid of the neutral filter.
[0024] An optical arrangement in accordance with Claim 10 is an apodization element that can be used for a number of application cases.
[0025] An optical arrangement in accordance with Claim 11 has a reduced number of optical interfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Exemplary embodiments of the invention are explained in greater detail below by reference to the drawings; in the drawings:
[0027] [0027]FIG. 1 shows a meridional section through a diffractive converging lens according to the prior art;
[0028] [0028]FIG. 2 shows a detail of FIG. 1;
[0029] [0029]FIG. 3 shows a detail, similar to FIG. 2, of a diffractive converging lens according to the invention;
[0030] [0030]FIG. 4 shows a detail, similar to FIG. 2, of a further diffractive converging lens according to the prior art;
[0031] [0031]FIG. 5 to 7 show schematic diagrams of the local diffraction efficiencies of the converging lenses according to FIGS. 2 to 4 as a function of the distance from the central point;
[0032] [0032]FIG. 8 shows a diagram with calculated structural heights of a diffractive converging lens similar to FIG. 3;
[0033] [0033]FIG. 9 shows a diagram with calculated local diffraction efficiency patterns of the diffractive converging lens having structural heights in accordance with FIG. 8 as a function of the distance from the central point;
[0034] [0034]FIG. 10 shows a diagram with calculated local phase patterns of the diffractive converging lens having structural heights in accordance with FIG. 8 as a function of the distance from the central point;
[0035] [0035]FIG. 11 shows a diagram with calculated structural widths of a diffractive converging lens similar to FIG. 3;
[0036] [0036]FIG. 12 shows an optical arrangement according to the invention comprising a diffractive converging lens in accordance with FIG. 4; and
[0037] [0037]FIG. 13 shows a schematic diagram with the local diffraction efficiency pattern of the optical arrangement in accordance with FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The diffractive converging lens denoted in total in FIG. 1 by the reference symbol 1 corresponds to the prior art. On one side, it has a plurality of diffraction structures 2 to 9 that are disposed rotationally symmetrically with respect to the optical axis 10 of the diffractive converging lens 1 . On the other side, the diffractive converging lens 1 has a flatly terminating counter surface 11 .
[0039] The central diffraction structure 2 has a convex surface. Its radial termination forms a cylindrical step surface 12 that is part of the diffraction structure 3 and surrounds the diffraction structure 2 annularly. Adjacent to the step surface 12 is a diffraction surface 13 that slopes radially outwards and that is likewise part of the diffraction structure 3 . The diffraction structures 4 to 9 likewise have, like the diffraction structure 3 , a step surface and a diffraction surface that alternate radially from the inside outwards in the diffractive converging lens 1 . In the meridional section of FIG. 1, this results in a structure, sawtooth-shaped in total, of that surface of the diffractive converging lens 1 situated opposite the counter surface 11 .
[0040] The diffraction surfaces of the diffraction structures 2 to 9 (cf. diffraction surface 13 ) slope outwards at an angle that is such that the light is preferentially guided into a certain order of diffraction for which the diffraction condition is fulfilled because of the widths of the diffraction structures 2 to 9 . Such an adapted shape of the diffraction structures is denoted as a “blaze profile”.
[0041] The height h of the diffraction structures 2 to 9 , i.e. their extension in the direction of the optical axis 10 from the respective highest point to the respective lowest point of the diffraction structure 2 to 9 , is equal for all the diffraction structures 2 to 9 . For the diffraction structures 3 to 9 , the height h corresponds to the extension of the step surfaces (cf. step surface 12 of the diffraction structure 3 ) parallel to the optical axis 10 .
[0042] The width of the diffraction structures 2 to 9 , i.e. the radial extension with respect to the optical axis 1 O, varies over the diffraction structures 2 to 9 in accordance with a required phase function and decreases continuously from the diffraction structure 2 to the diffraction structure 9 . The width r 7 of the diffraction structure 7 is shown as representative in FIG. 1. The width of a diffraction structure at a certain distance from the central point is in this case a measure of the phase function achieved in the diffractive converging lens 1 .
[0043] The heights h and also the widths r are of a size that is comparable with the wavelength of the light for which the diffractive converging lens 1 is to be used. The ratio of the width r and the wavelength used is in this case in the range between 1 and >100.
[0044] The rim region of the diffractive converging lens 1 is magnified yet again in the detail shown in FIG. 2.
[0045] The radial pattern of the diffraction efficiency T can be calculated on the basis of the electromagnetic diffraction theory for a diffractive converging lens 1 in accordance with FIGS. 1 and 2 having constant height of the diffraction structures.
[0046] The result of such a calculation is shown diagrammatically in FIG. 5. Proceeding from a diffraction efficiency value T0, i.e. the diffraction efficiency of the diffraction structure 4 , the diffraction efficiency T decreases towards the outermost diffraction structure 9 to a rim value TR. The diffraction efficiency T therefore decreases with respect to the distance R from the central point with decreasing width r of the diffraction structures 4 to 9 .
[0047] Further embodiments of diffractive converging lenses are discussed below. Components that correspond in this connection to those that have already been described above with reference to the drawing are given reference symbols increased by 100 in each case and are not explained in detail yet again.
[0048] The detail diagram of FIG. 3, which is similar to that of FIG. 2, shows a diffractive converging lens 101 according to the invention. The diffraction structures 104 to 109 have the same sawtooth-type basic shape as the corresponding diffraction structures 4 to 9 of the diffractive converging lens 1 . The widths r of the diffraction structures 104 to 109 are also equal to those of the diffraction structures 4 to 9 as, for example, a comparison of the widths r 7 of the diffraction structure 7 and r 107 of the diffraction structure 107 shows.
[0049] Those portions of the diffraction structures 104 to 109 extending furthest away from the counter surface 111 , that is to say the tips of the sawteeth, are at the same distance from the counter surface 111 for all the diffraction structures 104 to 109 , as is the case for the diffractive converging lens 1 according to the prior art. In the case of the diffractive converging lens 101 according to the invention in FIG. 3, however, the height of the step surfaces 114 to 118 of the diffraction structures 105 to 109 decreases with decreasing distance from the central point and, therefore, with increasing width of the diffraction structure. The height of the diffraction structure 105 , h 105 , is therefore less than the height of the diffraction structure 109 , h 109 .
[0050] The blaze profile of the diffraction structures of the diffractive converging lenses 101 may be designed as a continuously inclined surface or, alternatively, by means of a known multilevel structure having a staircase-type pattern.
[0051] [0051]FIG. 6 shows diagrammatically the pattern of the local diffraction efficiency of the diffraction structure 101 as a function of the distance from the central point. The diffraction efficiency T is constant between the diffraction structures 104 and 109 and equal to the rim value of the diffraction efficiency of the diffraction structure 109 , TR. This is due to the fact that two effects modifying the diffraction efficiency compensate in the case of the diffractive converging lens 101 : on the one hand, the diffraction efficiency increases with increasing width r of the diffraction structures 109 to 104 , as already discussed in relation to the diffractive converging lens 1 (cf. FIG. 5). On the other hand, the diffraction efficiency decreases with decreasing height of the diffraction structures 109 to 104 . In the case of the diffractive converging lens 101 , the height variation is aligned with the width variation in such a way that, in total, a constant diffraction efficiency TR results with respect to the distance R from the central point.
[0052] The local diffraction efficiency pattern in the case of a diffractive converging lens 101 that has diffraction structures with an outwardly decreasing width and increasing height, was discussed above with the aid of FIGS. 3 and 6. The result of quantitative calculations based on electromagnetic diffraction theory is shown in FIGS. 8 to 10 .
[0053] [0053]FIG. 8 shows the dependence of the height h, in nm, of the diffraction structures on the distance R from the central point for a diffractive converging lens having a structure that corresponds to the principle according to that of FIG. 3. The height of the diffraction structures at the rim for R=110 mm is h=480 mm. The height h of the diffraction structures decreases progressively in the direction of the central point of the diffractive lens down to a height h=429 nm at a distance R=33 mm from the central point. Plotted against the distance R from the central point, such a pattern of heights h of the diffraction structures results in a diffraction efficiency T that is shown in FIG. 9. Substituted in the calculation of the diffraction efficiency T as parameters were an illumination wavelength of 248.34 nm and also a refractive index of the material of the diffractive converging lens of 1.508. The diffraction structures have a blaze profile.
[0054] For both polarization directions TE (open triangles) and also TM (open circles), the diffraction efficiency remains approximately constant at a diffraction efficiency value of approximately 0.89. The diffraction efficiency values for the TE polarization tend to be minimally higher than those for TM polarization. Here, the calculation was again performed without an anti-reflection coating of the diffractive converging lens.
[0055] [0055]FIG. 10 shows the pattern of the phase P of the light passing through the respective diffraction structures in rad against the distance R from the central point for a height pattern of the diffraction structures in accordance with FIG. 8. The curve shape of the phase pattern corresponds qualitatively to that of the height pattern in FIG. 8. Proceeding from a relative value of 0 rad at R=100 mm, the phase P follows progressively down to a value of −0.06 rad at R=33 mm.
[0056] If a constant phase pattern is desired over the cross-section of the illumination beam for an optical arrangement having such a diffractive converging lens, a phase pattern of the type shown in FIG. 10 has to be precompensated for in other optical components, for example in refractive optical components.
[0057] [0057]FIG. 11 shows the pattern of the structural width r of the diffraction structures of the diffractive converging lens which results in the diffraction efficiencies in accordance with FIG. 9. Proceeding from the rim of the converging lens (R=110 mm), the structural width increases from a width of r=2.5 m to a width of r=60 min the region of the center of the converging lens (r=5 mm).
[0058] A further variant of a diffractive converging lens 201 according to the prior art is shown in FIG. 4. In the latter, the pattern of the heights h of the diffraction structures 204 to 209 is precisely the reverse of that for the diffractive converging lens 101 of FIG. 3, i.e. the heights h decrease from the innermost, widest diffraction structure 204 shown in FIG. 4 to the outermost, narrowest diffraction structure 209 . The height of the diffraction structure 209 , h 209 , is accordingly less than the height of the diffraction structure 205 , h 205 .
[0059] In the diffractive converging lens 201 , the two effects that modify the local dependence of the diffraction efficiency T enhance one another: on the one hand, the width r of the diffraction structures and, on the other hand, their height h decrease outwards, and this results in each case in a reduction in the diffraction efficiency. The consequence is the diffraction efficiency pattern that is shown diagrammatically in FIG. 7. In the latter, proceeding from a diffraction efficiency value T 0 of the diffraction structure 204 , the diffraction efficiency T decreases as a function of the distance R from the central point with a greater slope than in FIG. 5, thereby resulting in a lowest value of the diffraction efficiency, T min, that is lower in the case of the diffractive converging lens 201 than in the case of the diffractive converging lens 1 .
[0060] It is clear that practically any diffraction efficiency patterns can be established by means of required variations in the widths r and the heights h of the diffraction structures. In this connection, the widths r do not have to decrease monotonically from the inside outwards, as described above, but may also increase monotonically or even have other dependencies that can be described, for example, by exponential functions of the distance R from the central point and may have main and subsidiary maxima or minima.
[0061] The diffractive converging lenses 1 to 201 may have an anti-reflection coating to increase their diffraction efficiency.
[0062] An additional degree of freedom for setting a desired radial total efficiency pattern for usable light into which both the diffraction efficiencies and the transmissions of the optical elements involved enter results from the use of a neutral filter 220 . FIG. 12 shows an optical arrangement according to the invention that is exemplary for this purpose and that shows the combination of the neutral filter 220 with a diffractive optical element in accordance with FIG. 4. The neutral filter 220 is joined to the counter surface 211 of the diffractive converging lens 201 . This joint can either be made by means of a suitable optical adhesive or the diffractive converging lens 201 and the neutral filter 220 are coupled to one another optically by means of a liquid having matching refractive index and held in this position.
[0063] It is clear that the neutral filter 220 can be combined with any diffractive optical elements having varying structural heights, in particular also with that in FIG. 3.
[0064] The diffractive structure can also be applied directly to the neutral filter. For this purpose, the diffractive optical element and the neutral filter are made from one material. The diffractive optical element can then be structured in the neutral filter itself.
[0065] The neutral filter 220 has, in the region of the diffraction structure 204 , complete transparency, whereas it is completely opaque in the region of the diffraction structure 209 .
[0066] The total efficiency pattern of the optical arrangement comprising the diffractive converging lens 201 and the neutral filter 220 is illustrated in FIG. 13. In the latter, as in FIG. 7, the local diffraction efficiency pattern of the diffractive converging lens 201 is shown as a full line. The local total efficiency pattern of the optical arrangement comprising the diffractive converging lens 201 and the neutral filter 220 is shown in FIG. 13 as a chain-dot line. Proceeding from a value T0 for the innermost diffraction structure 204 in FIG. 12, the total efficiency of the optical arrangement decreases to 0 towards the rim.
[0067] Of course, the diffractive converging lens 201 and the neutral filter 220 may also be components that are spatially separated from one another.
[0068] Alternatively, the neutral filter may also be replaced by a metal coating of the diffractive converging lens. Such metal coatings, which have a required transmission pattern, are known.
[0069] The efficiency considerations stated within the framework of the description of the figures may also be put forward analogously for a reflective diffractive optical element. In this case, too, the same basic dependencies of the diffraction efficiency on the structural width or the structural height exist.
[0070] In the case of a reflective diffractive optical element, a reflective coating is normally used to optimize the reflection efficiency. In this connection, a metal coating or a dielectric, highly reflective (HR) coating may be used. The diffractive structure may be disposed in this latter case on or under the HR layer system. The material of the diffractive structure may differ in both cases from the materials used in the HR layer system. Particularly good efficiency results are obtained if the refractive index of the layer of the HR layer system that is immediately adjacent to the diffraction structures is chosen in such a way that the inner periodicity of the HR layer system is continued by the layer that is required by the diffraction structures. In the case of an HR layer system having alternating high-refractivity and low-refractivity layers, the first layer of the HR layer system that is immediately adjacent to the diffraction structures should, for example, be highly refractive if the layer that is required by the diffraction structures is of low refractivity.
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A diffractive optical element has a plurality of diffraction structures for a certain wavelength. These each have a width measured in the plane of the diffractive optical element and a height measured perpendicularly thereto. The widths and the heights of the diffraction structures vary over the area of the diffractive optical element. An optical arrangement comprising such a diffractive optical element has, in addition, a neutral filter. The efficiency of such a diffractive optical element and of such an arrangement can be optimized locally for usable light.
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RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application 61/607,893, entitled, “A Method to Fabricate Fine Pitch Probe Arrays Using Silicon,” filed 7 Mar. 2012, to Namburi, which is hereby incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] Embodiments of the present invention relate to the field of integrated circuit design, manufacture and test. More specifically, embodiments of the present invention relate to systems and methods for fine pitch probe arrays from bulk material.
BACKGROUND
[0003] Integrated circuit testing generally utilizes fine probes to make contact with test points of an integrated circuit in order to inject electrical signals and/or measure electrical parameters of the integrated circuit. Conventional circuit probes are produced singly, and manually assembled into an array corresponding to some or all of the test points on an integrated circuit.
[0004] Unfortunately, due to the constraints of producing the probes individually, and assembling them into an array, conventional integrated circuit probe arrays are generally unable to achieve a pitch, e.g., probe to probe spacing, of less than about 50 μm. In addition, conventional probes often have an undesirable high inductance, which may limit the frequency of test signals. Further, conventional integrated circuit probe arrays are typically unable to achieve necessary alignment accuracies in all three dimensions. Still further, such alignment and co-planarity deficiencies of conventional probes deleteriously limit the number of probes and the total area of a probe array, and hence the total area of an integrated circuit that may be tested at a single time. For example, a single conventional integrated circuit probe array assembled at a fine pitch may not be capable of contacting all test points on a large integrated circuit, e.g., an advanced microprocessor.
SUMMARY OF THE INVENTION
[0005] Therefore, what is needed are systems and methods for fine pitch probe arrays from bulk material. What is additionally needed are systems and methods for fine pitch probe arrays from bulk material with fine pitches and high positional accuracy. A further need exists for systems and methods for fine pitch probe arrays from bulk material that are compatible and complementary with existing systems and methods of integrated circuit design, manufacturing and test. Embodiments of the present invention provide these advantages.
[0006] In contrast to the conventional art in which an array of electronic probes is constructed by adding individual probes to form an assembly, embodiments in accordance with the present invention form an array of electronic probes from a bulk material, removing material to render the basis of an array of electronic probes.
[0007] In accordance with a first method embodiment, an article of manufacture includes an array of probes. Each probe includes a probe tip, suitable for contacting an integrated circuit test point. Each probe tip is mounted on a probe finger structure. All of the probe finger structures of the array have the same material grain structure. The probe fingers may have a non-linear profile and/or be configured to act as a spring.
[0008] In accordance with a method embodiment, a bulk material with first and second substantially parallel faces is accessed. A probe base is formed on the first face. A probe tip suitable for contacting an integrated circuit test point is formed on the probe base. The second face is mounted to a carrier wafer. Portions of the bulk material are removed to form a probe finger structure coupled to the probe base and the probe tip. The probe finger structure is coated with a conductive metal electrically coupled to the probe tip. Formation of the probe tip and probe base may include photolithography.
[0009] In accordance with another embodiment of the present invention, an electronic probe array for testing integrated circuits includes a plurality of individual probes, mechanically coupled and electrically isolated. Each individual probe includes a probe tip functionally coupled to a probe finger structure. The probe tip is of a different material from the probe finger structure. The probe tip is configured for contacting an integrated circuit test point. Each probe finger structure is formed from a same piece of bulk material. Each individual probe is coated with conductive metal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Unless otherwise noted, the drawings are not drawn to scale.
[0011] FIG. 1 illustrates a portion of an exemplary “through-silicon via” (TSV) carrier wafer, in accordance with embodiments of the present invention.
[0012] FIG. 2A illustrates formation of a probe block, in accordance with embodiments of the present invention.
[0013] FIG. 2B illustrates a formation of slots between rows of probes along one axis to form a probe block, in accordance with embodiments of the present invention.
[0014] FIG. 2C illustrates a plan view of a portion of a substrate after the formation of slots, in accordance with embodiments of the present invention.
[0015] FIG. 3 illustrates a die bonding of a probe block to a carrier wafer, in accordance with embodiments of the present invention.
[0016] FIG. 4 illustrates a sectional view of an array of individual probes, in accordance with embodiments of the present invention.
[0017] FIG. 5 illustrates application of a conductive metal coating to an array, in accordance with embodiments of the present invention.
[0018] FIG. 6 illustrates removal of the masking layer, exposing the probe tip, in accordance with embodiments of the present invention.
[0019] FIG. 7 illustrates a typical application of an array of probes, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
[0020] Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it is understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be recognized by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the invention.
Notation and Nomenclature
[0021] Some portions of the detailed descriptions which follow (e.g., FIGS. 1-7 ) are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that may be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
[0022] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “accessing” or “forming” or “mounting” or “removing” or “coating” or “attaching” or “processing” or “singulating” or “roughening” or “filling” or “performing” or “generating” or “adjusting” or “creating” or “executing” or “continuing” or “indexing” or “computing” or “translating” or “calculating” or “determining” or “measuring” or “gathering” or “running” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Fine Pitch Probe Array from Bulk Material
[0023] FIG. 1 illustrates a portion of an exemplary “through-silicon via” (TSV) carrier wafer 100 , in accordance with embodiments of the present invention. Wafer 100 is illustrated as being formed in silicon, although any suitable material may be utilized. Wafer 100 should generally have parallel top and bottom faces. Any suitable plan-view shape may be used. Wafer 100 comprises a silicon substrate 101 with oxide on sidewalls of the silicon via to insulate the metal via from the semiconducting silicon.
[0024] Carrier wafer 100 also comprises a sacrificial ground layer, formed of any suitable material. Sacrificial ground layer 102 will be utilized during wire electrical discharge machining (wire-EDM) processing, further described below, and should be suitable for such purpose. Carrier wafer 100 further comprises a plurality of solder pads 103 . Solder pads 103 may comprise an alloy of gold (Au) and tin (Sn), at an exemplary thickness of 2 μm. Under laying solder pads 103 are a plurality of under-bump-metallurgy (UBM) thin film stacks 105 . UBM thin film stacks 105 may comprise a film of, for example, titanium (Ti), platinum (Pt) and gold (Au). It is appreciated that other suitable materials may also be used. An insulating layer 104 , e.g., silicon dioxide (SiO 2 ), or other suitable material, separates the stacks of solder pads 103 and UBM 105 .
[0025] Carrier wafer 100 further comprises a plurality of through-silicon vias (TSV) 106 . Through silicon vias 106 provide electrical coupling from the solder pads 103 to the other side of the carrier wafer 100 , and to sacrificial ground layer 102 .
[0026] FIG. 2A illustrates formation of a probe block 200 , in accordance with embodiments of the present invention. Probe block 200 comprises a substrate 201 comprising silicon, although any suitable material may be utilized, for example, beryllium copper. Silicon substrate 201 may be similar to silicon substrate 101 , illustrated in FIG. 1 . Silicon substrate 201 may comprise highly doped p-type silicon, doped with boron (B) to a concentration of about 10 18 dopants/cm 3 , for example, which may produce an electrical resistivity of 0.001 ohm-cm. The thickness of the substrate 201 determines the overall height of the probe array.
[0027] Probe block 200 additionally comprises a plurality of solder pads 203 . Solder pads 203 may be similar to solder pads 103 , illustrated in FIG. 1 . Solder pads 203 may comprise an alloy of gold (Au) and tin (Sn), at an exemplary thickness of 2 μm. Under laying solder pads 203 are a plurality of under-bump-metallurgy (UBM) thin film stacks 205 . UBM films 205 may be similar to UBM films 105 , illustrated in FIG. 1 . UBM films 205 may comprise a film of, for example, titanium (Ti), platinum (Pt) and gold (Au). It is appreciated that other suitable materials may be used.
[0028] Probe block 200 further comprises a plurality of probes 210 . Probes 210 comprise a probe base 211 and a probe tip 212 . Probe tip 212 may comprise any material suitable for the probing application, e.g., suitable to contact an integrated circuit test point, for example, a noble metal, e.g., ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir) and/or, platinum (Pt). (It is appreciated that gold (Au) is often included in the noble metals, but is generally considered too soft for probing.) The probe tip 212 and the upper face of the probe base 211 are masked with a masking layer 213 , e.g., a non-conductive polymer. The probe base 211 may be fabricated by sputtering a seed layer on one side of the wafer, and lithographically patterned and plated. Probe tips 212 may be fabricated on top of the probe base by lithographically patterning photoresist, plating the tip material and etching the seed layer between the tip bases. The probe tips 212 may be planarized if necessary for a smooth finish. The probe tips 212 should then coated to protect them from the rest of the process.
[0029] FIG. 2B illustrates a formation of slots 251 between rows of probes 210 along one axis to form probe block 250 , in accordance with embodiments of the present invention. It is appreciated that slots 251 represent the absence of substrate material. In some embodiments, slots 251 may remove an entire thickness of substrate 201 . It is appreciated that substrate 201 is not completely singulated; portions of substrate 201 remain coupled outside of the plane of FIG. 2B . Slots 251 may be formed by any suitable process, including, for example, deep reactive ion etching (DRIE).
[0030] FIG. 2C illustrates a plan view of a portion of substrate 201 after the formation of slots 251 , in accordance with embodiments of the present invention. Slots 251 are substantially parallel, and separate “rows” of probes 210 from one another. Mask 213 is not illustrated in FIG. 2C for clarity.
[0031] FIG. 3 illustrates a die bonding 300 of probe block 250 to carrier wafer 100 , in accordance with embodiments of the present invention. Bond pads 103 ( FIG. 1 ) are bonded to bond pads 203 ( FIGS. 2A , 2 B) by any suitable process.
[0032] FIG. 4 illustrates a sectional view of an array 400 of individual probes 401 , in accordance with embodiments of the present invention. It is to be appreciated that the plane of FIG. 4 is perpendicular to the plane of FIG. 3 . For example, the plane of FIG. 4 is parallel to, but not coincident with, the slots 251 , as illustrated in FIG. 2C . Individual proves 401 comprise a probe tip 212 , a probe base 211 and a probe finger structure 402 . It is appreciated that all probe fingers 402 will have the same material grain structure, as they are formed from the same block of material, e.g., single crystal silicon.
[0033] It is to be appreciated that individual probes 401 may have a complex shape in at least one dimension, in accordance with embodiments of the present invention. For example, as illustrated in FIG. 4 , probe fingers 401 are not linear, e.g., they are “bent” to the right. Such a profile, in one or more dimensions, may allow each individual probe to function as a spring, allowing for compliance to slight irregularities in a surface of an integrated circuit, and providing a restorative force to keep the probe tip, e.g., 212 , in contact with an integrated circuit test point.
[0034] In accordance with embodiments of the present invention, such “non-straight” or non-linear probe profiles may be accomplished by wire electrical discharge machining (wire-EDM). For example, a wire of about 12 μm in diameter may be used to machine probes at fine pitch geometries less than 40 μm. It is appreciated that a probe pitch may be different in X and Y dimensions, and it is not necessarily the same, even in the same dimension. Although the probe fingers 401 are illustrated as being “straight” in the plane of FIG. 2B , wire electrical discharge machining could be applied to that stage as well, e.g., replacing deep reactive ion etching, to produce a more complex shape in that dimension, as well, in accordance with embodiments of the present invention. It is further appreciated that embodiments in accordance with the present invention may form probes with a pitch greater than about 40 μm. For example, a wire of greater than about 12 μm in diameter may be used to machine probes at larger pitches. Probes formed in accordance with embodiments of the present invention at such larger pitches continue to enjoy significant advantages over the conventional art, including, for example, lower cost, less complexity and exceptional precision in probe tip positional accuracy in all three dimensions.
[0035] FIG. 5 illustrates application of a conductive metal coating 501 to array 400 , in accordance with embodiments of the present invention. The conductive metal coating 501 may comprise gold (Au) and/or copper (Cu), or other suitable materials, and may be applied by any suitable process, including, for example, immersion plating or electro-less plating processes. The thickness of the conductive metal coating 501 may be determined by the required current carrying capability of the probes. Conductive metal coating 501 may not be required in the case that material 201 is a metal such as berellium-copper (BeCu) since it is sufficiently conductive, unlike doped silicon.
[0036] In FIG. 6 , the masking layer 213 ( FIG. 2 ) is removed, exposing the probe tip 212 , via any suitable process, for example, using a dry reactive ion etch process or by using suitable wet chemistry. In addition, the sacrificial ground layer 102 ( FIG. 1 ) is removed. In this manner, an array of electrical probes 600 is formed from a bulk material, in accordance with embodiments of the present invention.
[0037] FIG. 7 illustrates a typical application of array of probes 600 ( FIG. 6 ), in accordance with embodiments of the present invention. As illustrated in FIG. 7 , the array of electrical probes 600 is bonded to a space transforming substrate 701 . Space transforming substrate 701 serves to transform the spacing of the probe heads 712 , which may be on a pitch suitable for probing integrated circuits, e.g., less than or equal to about 40 μm, to a pitch more suitable for printed circuit boards, e.g., about 1 mm.
[0038] Substrate 701 may be similar to substrate 101 ( FIG. 1 ), although that is not required. Space transforming substrate 701 is electrically and mechanically bonded to array of probes 600 via any suitable processes and materials, for example via solder bonding pads 703 . Bottom bond pads 704 serve to couple space transforming substrate 701 to a higher level assembly, for example, a printed circuit board.
[0039] In accordance with embodiments of the present invention, the individual probes of the array 600 are formed from a bulk material, e.g., from single crystal silicon with a high modulus. Such material functions as a spring without any appreciable plastic deformation. The complex shape increases the spring characteristic of the probes, allowing for compliance to slight irregularities in a surface of an integrated circuit, and providing a restorative force to keep the probe tip, e.g., 212 , in contact with an integrated circuit test point. The probe tips exhibit a fine pitch, e.g., less than 40 μm, with excellent planarity and tip positional accuracy, as the probe tips are lithographically defined. The probe array has a high current carrying capability due to the conductive metal coating. Further, probe arrays in accordance with the present invention may be produced with shorter lead times and at reduced cost in comparison with the conventional art, as there is no manually assembly, and the processes leverage the economics of integrated circuit manufacturing.
[0040] Embodiments in accordance with the present invention provide systems and methods for fine pitch probe arrays from bulk material. In addition, embodiments in accordance with the present invention provide systems and methods for fine pitch probe arrays from bulk material with fine pitches and high positional accuracy. Further, embodiments in accordance with the present invention provide systems and methods for fine pitch probe arrays from bulk material that are compatible and complementary with existing systems and methods of integrated circuit design, manufacturing and test.
[0041] Various embodiments of the invention are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the invention should not be construed as limited by such embodiments, but rather construed according to the below claims.
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Fine pitch probe array from bulk material. In accordance with a first method embodiment, an article of manufacture includes an array of probes. Each probe includes a probe tip, suitable for contacting an integrated circuit test point. Each probe tip is mounted on a probe finger structure. All of the probe finger structures of the array have the same material grain structure. The probe fingers may have a non-linear profile and/or be configured to act as a spring.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation, under 35 U.S.C. § 120, of copending international application PCT/EP2005/055986, filed Nov. 15, 2005, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German application DE 20 2004 018 084.7, filed Nov. 22, 2004; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to an absorber for a pipe or sewer structure comprising at least one feed connection and at least one return connection and one or more absorber channels that connect a feed to a return. The invention also relates to a pipe or sewer structure comprising such an absorber.
Various heat exchanger installations have been disclosed by way of which heat contained in the wastewater can be recovered, for example to supply the heat recovered from the wastewater into a district heating network. German utility model DE 20 2004 005 768 U1 describes a component for channeling water which has a recess in its bottom region. The recess extends over the entire length of the component and serves to accommodate a plurality of juxtaposed square metal pipes intended to form a heat exchanger device (absorber). These metal pipes are arranged in the recess in a grout which, following insertion of the pipes, is poured into the gaps which remain in particular between the individual pipes. By virtue of the metal pipes held in the recess by means of the grout, the recess itself is eliminated again, with the result that the component, in particular when it is embodied as a pipe, does not have its cross-sectional area reduced by the absorber. The pipes inserted in the recess are interconnected at their ends by connecting pieces such that liquid which is fed in from a feed and used for conveying heat is channeled through the pipes and is carried off by a return. The feed and the return are conveniently situated in a manhole. The component known from this document serves to recover heat from the wastewater channeled through the component. The cooler liquid fed into the bottom region of the component via the feed is heated as it flows through the heat exchanger device by the warmer wastewater channeled over the absorber. The recovered heat is delivered via a heat pump connected to the return so that it can be used subsequently.
Finally, the component with its absorber described in this document is one in which, unlike the sewer pipe described in German published patent application DE 35 21 585 A1, the heat exchanger device is integrated subsequently into the pipe wall and not during the construction of the sewer pipe.
To achieve the best possible heat transfer from the wastewater to the pipes of the heat exchanger device, metal pipes are used in this already known heat exchanger device. Although these pipes have good thermal conductivity, the disadvantage with these pipes is that the individual pipes have to be welded together at their ends to form relatively long heat exchanger devices. Moreover, such pipes are not suited for use in existing sewer structures, in particular in those which do not have a recess in their bottom region. Existing sewer structures often have damage, edges or discontinuities which impede the installation of such a heat exchanger device, and such installation can only be achieved with considerable extra expenditure.
German patent DE 197 19 311 C2 describes a further heat exchanger device for installation in a sewer pipe. The installation of that prior art heat exchanger device with its absorber in an existing sewer pipe considerably reduces the free cross-sectional area in the bottom region of the pipe. Furthermore, such an installation unit which significantly increases the bottom region forms a step within the sewer, this again being undesirable. Finally, in that prior art heat exchanger device, too, the same disadvantages arise as described with respect to the above noted German utility model DE 20 2004 005 768 U1.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide an absorber for recovering heat from water-carrying conduits or pipes, for example sewer pipes, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and also to propose a pipe or sewer structure suitable for recovering heat.
With the foregoing and other objects in view there is provided, in accordance with the invention, an absorber for a pipe or sewer structure, comprising:
at least one feed connection;
at least one return connection;
one or more absorber channels fluidically connected between the feed connection and the return connection. The absorber channels extend through an absorber channel mat forming a physical unit. The absorber channel mat is made of a material having flexible properties, at least while the absorber channel mat is being laid into the pipe or sewer structure.
This object is achieved according to the invention by a generic absorber mentioned in the introductory part in which the absorber channels of the absorber are combined in an absorber channel mat to form a physical unit, and the absorber channel mat is made of a material having flexible properties at least while it is being laid in the pipe or sewer structure. A pipe or sewer structure according to the invention comprises such an absorber, the absorber being arranged in the bottom of the structure and being held in this position by a tube which is drawn into the structure and lines the inner side of the structure.
In the absorber the individual absorber channels are combined to form a physical unit. This physical unit is configured as a flexible absorber channel mat, with, in principle, the flexible properties of the absorber channel mat needing initially to be present only while it is being laid in a pipe or sewer structure. By contrast, the flexible properties of the absorber channel mat are not required in principle for operation of the absorber. Therefore, the absorber channel mat can retain its flexible properties even after being installed in a pipe or sewer structure. It is equally possible for the flexible material properties of the absorber channel mat to disappear after it is laid, for example by a hardening process or the like. The flexible properties of such an absorber channel mat in which the individual absorber channels are combined to form a physical unit make it easy to mount the absorber channel mat. For example, it can be drawn into an existing pipe or sewer structure, thus making it possible in particular for it to be installed even in pipes or sewers having a smaller diameter. Owing to the flexible properties of the absorber channel mat, edge discontinuities or the like within an existing pipe or sewer structure can be readily bridged. As a result of these material properties, the absorber channel mat lies flat on the upper side of the bottom of the pipe or sewer structure. After being drawn in/laid within such a structure, the absorber channel mat bears snugly by its underside on the bottom of the structure, in particular without additional measures having to be taken in principle for this purpose. The fact that the absorber channel mat bears snugly has the advantage of then establishing heat transfer from the structure in its bottom region to the absorber channel mat, and in particular to the heat exchanger liquid conveyed in the absorber channels. Such heat transfer is desirable since it is thus also possible to recover heat from the ground near the surface via the absorber. To achieve better compensation for uneven areas in the bottom region of a pipe or sewer structure, provision is made according to one embodiment of the invention for the underside of the absorber channel mat to have not only flexible properties but also resilient properties. Uneven areas, small stones or the like thus press into the underside of the absorber mat and in this way avoid the formation of relatively large regions in which the absorber channel mat does not bear by its underside on the bottom of the structure.
In such an absorber mat, the at least one absorber channel advantageously has a meandering course between its feed and its return. Such an absorber mat can be formed either in one piece or from an assembly consisting of a plurality of individual pieces. In the latter case, a central piece can be provided for example in which individual absorber channel sections are arranged so as to extend parallel to one another. The central piece of such an absorber channel mat can be produced in an endless form and thus unrolled in situ from a roll when being drawn into a pipe or a sewer. Not only does this allow the formation of absorbers of variable length, but such a central piece also makes it possible in particular for long absorber runs to be formed. Two end pieces are used to connect the individual absorber channel sections of such a central piece, these end pieces advantageously being made of the same material as the central piece of the absorber channel mat. The end pieces are designed to interconnect absorber channel sections which extend adjacent to one another and to the longitudinal extent of such a central piece in order to provide a single absorber channel or else a plurality of parallel absorber channels having a meandering course. One of the end pieces of such an absorber mat additionally comprises both one or more feed connections and one or more return connections. The number of feed and return connections is governed by the number of absorber channels which are to be operated independently of one another. To line a pipe or sewer, it is also readily possible for a plurality of absorber channel mats to be arranged so as to extend next to one another. With the provision of a plurality of channels extending parallel to one another in such an absorber mat, according to another operating mode the flow through these channels can also take place with all the channels pointing in the same direction, in which case a feed connection is arranged at one end of such an absorber channel mat and a return connection is arranged at the other end. Such an arrangement of the feed and return connections will be used in particular if the absorber channel mat has only a single channel.
Such an absorber channel mat has only a relatively small height. Nevertheless, it is advantageous for such an absorber channel mat to be provided at its longitudinal and transverse edges with outwardly tapering lips as transition pieces for joining the surface facing into the interior of the pipe or sewer to the pipe or sewer wall.
According to a further embodiment, provision is made for the absorber channel mat to have a planar underside and a corrugation extending in the transverse direction to the wastewater flow direction. The absorber channel or its absorber channel sections is or are formed within the elevations of the corrugation. This measure serves the purpose of increasing that surface of the individual absorber channel sections which faces into the interior of the pipe or sewer structure.
The absorber can be produced from various materials as long as the above-described properties are present. For example, various plastics or else rubber mixtures are suitable for forming the absorber channel mat. Should such an absorber channel mat be composed of a plurality of pieces, the individual elements can be connected to one another by adhesive bonding, welding, vulcanizing or by a plug connection.
The above-described absorber or its absorber channel mat is especially suitable for equipping existing pipe and sewer structures, in particular if these are in need of repair anyway and are repaired by drawing in a hardening tube (inliner). When carrying out such a repair, it is readily possible for the absorber or its absorber channel mat to be drawn in at the same time as such an inliner is drawn in to line the inner wall of the structure. The inliner used for repairing the pipe or sewer hardens after it has been drawn in and thus ensures that the absorber is secured at its intended position in the bottom region of the structure. Moreover, the inliner virtually clamps the absorber channel mat between the outer side of the inliner and the inner side of the structure, and therefore this measure also ensures that the underside of the absorber channel mat bears snugly against the upper side of the bottom. Owing to the flexible properties of the inliner, the latter bears readily against the upper side of the absorber channel mat with full surface contact, even if the absorber channel mat is corrugated with respect to the inner side of the pipe or sewer structure in the above-described manner. This structuring of the absorber channel mat is thus reproduced through the repair tube, with the result that the desired increase in the absorber channel surface is preserved.
According to a further exemplary embodiment, the absorber channel mat described forms part of such an inliner intended for the repair of a pipe or sewer structure and, for example, is woven during its production into this inliner or else is subsequently laminated onto the inliner. This has the advantage that, when repairing the pipe or sewer structure, the absorber channel mat is introduced into the structure at the same time as the inliner is drawn in. If the absorber channel mat forms part of such a plastic inliner used for repairing the pipe or sewer structure, the walls forming the absorber channels, at least in terms of the properties which keep the channels open, can be assumed by the inliner itself. It should then be ensured that after the inliner has been drawn in and before it has hardened, the absorber channels are kept open until the tube has hardened, for example using compressed air or the action of liquid.
In the case of a protective sheet (preliner) being drawn in below such a repair tube (inliner), the absorber channel mat can also form part of this protective sheet inliner and be drawn in therewith into the pipe or sewer structure.
In the case that not only the absorber channel mat but also an inliner used for repairing the pipe or sewer structure, if appropriate together with a preliner, are to be introduced into the structure, the absorber channel mat will be arranged to suit the preferred heat recovery in the particular circumstances. If recovering heat from the surrounding ground is the main concern, the absorber channel mat will be arranged under the liner or liners and thus advantageously directly adjoining the inner side of the pipe or sewer structure to be repaired. If, by contrast, recovering heat from the wastewater is the main concern, it will be considered to bring the absorber channel mat as close as possible into the region of the wastewater. Irrespective of the two possible arrangements described above by way of example, it will be understood that heat exchange into the heat exchanger fluid carried in the absorber channels occurs in any event both from one side and from the other side.
According to a further embodiment of the invention, it is proposed that at least two absorber channel mats be arranged so as to lie one above the other, for example also in such a way that their absorber channels are arranged with an offset to one another. In such an embodiment, provision can be made for example for an inliner intended for repair to be arranged between the two absorber channel mats.
Even if the choice of the material used to form the absorber channel mat and, in addition, the possible use of a repair tube mean that the heat transfer from the wastewater to the heat exchanger medium, for example water, carried in the absorber channels has poorer values under certain circumstances than when metal pipes are used, the advantages afforded by this absorber predominate nevertheless. Such a drawback can be readily overcome by correspondingly increasing the length of the absorber, which, as described above, is again readily possible.
The above description of the absorber was given by way of an example in which heat from the ground and/or from the liquid flowing in the pipe or sewer structure is recovered via the absorber. It is also readily possible for the absorber to be operated in reverse, so that heat is released via this absorber into the ground and/or to the liquid flowing in the structure. Within such an embodiment, the absorber can form part of an air-conditioning device, for instance for a building. It is likewise possible for the absorber to be operated alternately in one or other of the above-described operating modes.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in absorber for a pipe construction or channel construction and pipe construction or channel construction provided with this absorber, 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.
The construction and method of operation of the invention, however, together with additional objects 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 SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a schematic cross section taken through a sewer pipe extending in the ground, with an absorber according to a first embodiment of the invention installed in a bottom region of the pipe;
FIG. 2 is a schematic plan view of the absorber of FIG. 1 ;
FIG. 3 is a cross section of a further embodiment of an absorber channel mat according to the invention; and
FIG. 4 is a schematic plan view showing a further embodiment of an absorber for a pipe or sewer structure according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawing in detail and first, in particular, to FIG. 1 thereof, there is illustrated a sewer pipe 1 laid in the ground 2 . The sewer pipe 1 comprises an absorber 3 which is arranged in the bottom region, or the floor, of the sewer pipe 1 . The absorber 3 , which may also be referred to as a heat exchanger, comprises a plurality of absorber channel sections 5 which are combined in an absorber channel mat 4 . The longitudinal-side ends of two adjacent absorber channel sections 5 are in each case alternately interconnected so that in each adjacent absorber channel section 5 the liquid introduced therein via a feed flows in the opposite direction. The absorber channel mat 4 is provided at its longitudinal and transverse sides with respective transition lips 6 in order to form a gradual transition from the inner surface of the sewer pipe 1 to the upper side of the absorber channel mat 4 , thereby avoiding the formation of steps. The absorber 3 and, in particular, its absorber channel mat 4 are made of a flexible material, for example a rubber mixture or the like.
The absorber 2 is shown in a schematic plan view ( FIGS. 2 and 4 ) and an inside view ( FIG. 3 ). The flow direction of the heat exchanger medium, for example water, is indicated therein by arrows. The absorber 3 comprises a feed 7 , or supply stub 7 , which is connected via a feed connection 8 of an end piece 9 . The end piece 9 interconnects adjacent absorber channel sections 5 . Furthermore, a return 11 is connected to the end piece 9 at its return connection 10 . In a manner which is not shown in more detail, the feed 7 and the return 11 are guided out of the ground 2 through a manhole connecting the sewer pipe 1 to the surface and are coupled to a heat pump. The absorber channel mat 4 is provided at its end situated opposite the end piece 9 with a further end piece 12 by means of which, in turn, adjacent absorber channel sections 5 can be interconnected, so that the absorber channel mat 4 , which, in the exemplary embodiment represented, is composed of the two end pieces 9 , 12 and a central piece 13 forming the absorber channel sections 5 , forms a single absorber channel which extends between the inlet 7 and the return 11 .
In the exemplary embodiment represented in FIG. 1 , the absorber 3 or its absorber mat 4 has been drawn into the sewer pipe 1 which forms part of an existing sewer pipe system. To secure the absorber channel mat 4 in the bottom region of the sewer pipe 1 , use is made of an inliner 14 which lines the inner side of the sewer pipe 1 and which is hardened after being drawn into the sewer pipe 1 . Techniques for drawing in and hardening such an inliner 14 are sufficiently well known. In the exemplary embodiment represented here, the inliner 14 also serves at the same time for the repair of the sewer pipe system with its sewer pipe 1 . Thus, not only is the sewer system repaired on its inner side by drawing in the inliner 14 , but the absorber 3 is also secured at the same time. Furthermore, the inliner 14 protects the absorber channel mat 4 from direct contact with the wastewater 15 carried in the sewer pipe 1 . When installing the flexible absorber 3 in a sewer pipe 1 in the manner described with respect to FIG. 1 , the absorber 3 does thus not necessarily need to have wastewater-resistant properties. These properties are possessed by the inliner 14 which separates the absorber channel mat 4 from the wastewater 15 .
The flexible properties of the absorber channel mat 4 , in which respect the underside of the absorber channel mat 4 is additionally resilient in the exemplary embodiment represented, cause the underside to bear snugly and with full-surface contact against the inner side of the sewer pipe 1 without additional binders having to be used. The absorber 3 can thus be used to absorb heat from the wastewater 15 and from the sewer pipe 1 . Although such an absorber 3 will generally be provided in the sewer pipes of a residential area, in which pipes the wastewater ought normally be warmer than the temperature of the surrounding ground 2 and of the sewer pipe 1 , the absorber 3 , by virtue of its virtually full-surface contact with the pipe 1 , can also be used on those sections of pipe which carry cooler wastewater so as then to absorb heat from the ground. Typically, sewer pipes are installed in the ground to a depth of 2-3 m, which means that ground heat can be recovered in this way particularly in the cooler winter months.
FIG. 3 illustrates a cross section through a further absorber channel mat 16 which has the same basic construction as the absorber channel mat 4 of FIG. 1 . Unlike the absorber channel mat 4 , the mat illustrated here is formed with an upwardly corrugated upper wall, that is, the individual absorber channel sections 17 are designed with a domed upper wall or a convex rounding, thereby increasing that surface of the absorber channel sections 17 which faces the wastewater.
FIG. 4 shows yet a further absorber channel mat 18 whose absorber channel sections 19 extend transversely to the longitudinal extent of the absorber channel mat 18 . The flow direction of the heat-exchanging fluid is depicted in this plan view, along a meandering course which, in this case extends chiefly transversely to the flow direction of the sewage. The meander of FIG. 2 extends chiefly in the direction of the sewage flow.
The absorber channel mats 4 , 16 , 18 described can be formed in one piece by an extrusion method or else in two pieces by two interconnected material layers. In the latter case, the sections which separate the absorber channel sections from one another form the connection points between the upper and lower material layer. If appropriate, use can be made of webs to increase the spacing between the upper material layer and the lower material layer or to provide the absorber channel mat with a smooth upper side and a smooth lower side.
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An absorber for a pipe or sewer structure has at least one feed connection and at least one return connection. One or more absorber channels connect a feed to a return stub. The absorber channels of the absorber are combined in an absorber channel mat to form a physical unit, and the absorber channel mat is made of a material having flexible properties, at least while it is being laid in the pipe or sewer structure.
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BACKGROUND OF THE INVENTION
This invention relates to a furniture hinge for pivotally connecting two parts of a piece of furniture, and more particularly to a hinge for pivoting a door to the frame of a piece of furniture.
A conventional furniture hinge comprises a first hinge component mounted on one part of a piece of furniture, a second hinge component mounted on the other part of the piece of furniture, and a pivotal connection between the components for effecting pivotal movement of one part of the piece of furniture relative to the other. A known type of hinge component includes a cup-shaped fastener member anchored in a counter-sunk bore in a surface of one of the parts of the piece of furniture, and a hinge arm that is adjustably seated in the cup-shaped fastener for permitting limited adjustment to the hinge arm member which carries a hinge shaft that defines the pivotal axis of the hinge. Despite its relative complex design, such a hinge component permits the hinge arm member to be adjusted along only a single axis that is transverse and perpendicular to the axis of the pivot shaft. Manufacturers of contemporary furniture, however, have increasing need for hinges that also permit the hinge arm member to be adjusted along an axis parallel to the axis of the hinge shaft. Ideally, the hinge arm member should be adjustable along three mutually perpendicular axes, namely, along an axis perpendicular and parallel to the surface of one of the parts of the piece of furniture, and along axes perpendicular and parallel to the axis of the hinge shaft.
SUMMARY OF INVENTION
A hinge component according to the present invention comprises a fastener member adapted to be attached to one part of a piece of furniture; a carrier member mounted in a cavity within the fastener member for adjustable displacement along a first axis; and a hinge arm member which carries a hinge shaft defining the pivotal axis of the hinge component. The hinge army member is mounted in a guide groove formed in the carrier member for adjustable displacement relative thereto along a second axis perpendicular to the first axis. The hinge member is releasably clamped between the carrier member and the fastener member by a fastener passing between the two last mentioned members. Thereafter, the hinge arm member can be adjustably displaced relative to both the fastener and the carrier member along a third axis perpendicular to both the first and second axes by utilizing an adjustment screw engaging the hinge arm member and the fastener member. As a consequence of this construction, the hinge shaft carried by the hinge arm member can be adjusted along three mutually perpendicular axes.
The carrier member preferably comprises a disc-like plate provided on one surface with the guide groove which receives a tongue on the hinge arm member. The guide groove, at least in the vicinity of the portion receiving the fastener, is shallower than the tongue and faces a wall segment of the fastener member which is cup-like in construction. A single threaded fastener passing through the wall segment and threaded into the carrier member will clamp the tongue of the hinge arm member between the carrier member and the fastener member to define a hinge component according to the present invention which is particularly simple in design and economical in construction yet will provide the required degrees of adjustment for the hinge shaft of the component.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention is described below in connection with the accompanying drawings wherein:
FIG. 1 is an exploded perspective view of a hinge component according to the present invention including a fastener member adapted to be attached to a side wall of a piece of furniture, a carrier member, and a hinge arm member carrying a hinge shaft defining the pivotal axis of the hinge component;
FIG. 1A is a perspective view of the hinge arm member of FIG. 1 but in a position rotated about 180° about the axis of the hinge shaft;
FIG. 2 is a perspective view of the hinge arm member mounted on the carrier member;
FIG. 3 is a rear, perspective view of the fastener member showing its cup-like construction, and a preassembly consisting of the hinge arm member preassembled on the carrier member prior to insertion of the preassembly into the fastener member;
FIG. 4 is similar in FIG. 3 except the preassembly is shown inserted into the fastener member;
FIG. 5 is a perspective view of a completely assembled hinge component according to the present invention prior to mounting of the same into a side wall of the piece of furniture provided with a counter-sunk bore for receiving the fastener member;
FIG. 6 is a view similar to FIG. 5 but showing the hinge component mounted on the piece of furniture;
FIG. 7 is a front view of the hinge component mounted on a piece of furniture;
FIG. 8 is a section along the line I--I of FIG. 9;
FIG. 9 is a section taken along the line II--II of FIG. 8;
FIG. 10 is a section taken along the line III--III of FIG. 9;
FIG. 11 is similar to FIG. 7 but shows another position of the hinge arm member of the fastener member;
FIG. 12 is a section taken along the line IV--IV of FIG. 13;
FIG. 13 is a section taken along the line V--V of FIG. 12; and
FIG. 14 is a section taken along the line VI--VI of FIG. 13.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring first to FIGS. 5 and 6, reference numeral 1 designates a hinge component according to the present invention mounted in side wall 3 of a piece of furniture. Component 1 comprises a single hinge shaft 2 that is spaced from edge 3' of wall 3 which contains counter-sunk bore 4 that opens into edge 3'. Barb-like ribs 6 formed on the outer periphery of the cup-shaped portion of fastener member 5 anchor the component in bore 4 such that flat segment 7 on member 5 is flush with edge 3' of side wall 3 of the piece of furniture.
As shown in FIG. 3, fastener member 5 includes wall segment 9 defining the bottom of the cup-shaped member and an interrupted cylindrical wall perpendicular to segment 9. Cavity 8 is closed after member 5 is seated in bore 4 (see FIG. 6). Support member 10 is disc-shaped and fits into cavity 8. One surface of member 10 is provided with lengthwise guide groove 11 (FIG. 1) extending from edge-to-edge, the groove having a generally U-shaped cross-section with a bottom surface that includes support face 12 adjacent one edge. Sides 13 and 14 defining the groove are formed by two wall segments that extend in a lengthwise direction, i.e., in the direction of double arrow A. The width of groove 11 corresponds to the width of tongue 15 on hinge arm member 16 carrying hinge shaft 2 whose axis defines the pivotal axis of the hinge component. Tongue 15 is thicker than the depth of at least a part of groove 11 and is slidably received therein for movement in the direction of double arrow A (see FIG. 1).
As shown in FIG. 1, guide pins 17 and 18 on faces 13 and 14 of carrier member 10 face wall segment 9 of fastener member 5, and seat in guide slots 19 and 20 (see FIG. 10) located on the inside of wall segment 9 when carrier member 10 is nested in cavity 8 of member 5. Slots 19 and 20 extend in a direction parallel to the direction of hinge shaft 2 when the members are assembled into the component, that is, in the direction of double arrow B (FIG. 1). Guide pin 17 and 18, together with guide slots 19 and 20 permit adjustment of the carrier member 10 on fastener member 5 in the direction of double arrow B.
A single screw 21 is used to attach hinge arm member 16 to both carrier member 10 and fastener member 5. Screw 21 passes through slotted hole 22 (FIGS. 5 and 6) in wall segment 9 and through clearance slot 23 of tongue 15 to engage threaded hole 24 in the bottom surface of guide groove 11, i.e., in the adjacent support face 12 of the carrier member. Because the depth of groove 11 in the region adjacent hole 24 is less than the thickness of tongue 15, hinge arm member 16 will be clamped between the bottom surface of guide groove 11 and the inside of wall segment 9 of fastener member 5 when screw 21 is threaded into hole 24.
In order to adjust hinge shaft 2 in a direction perpendicular to wall segment 9, i.e., in the direction of double arrow C (see FIG. 1), and perpendicular to the directions of double arrows A and B, a threaded hole 25 is provided in tongue 15 for receiving adjustment screw 26 whose head is received in recess 27 (see FIGS. 8 and 12) on the inner surface of wall segment 9 of fastener member 5. Slot 29 in wall segment 9 is elongated in the direction of double arrow B and opens into recess 27 to provide clearance for a tool, such as a screw driver, to pass through wall 9 into recess 27 and engage slot 28 in the head of adjustment screw 26 when the latter is threaded into hole 25. Recess 27 is large enough in the directions of double arrows A and B to permit clearance for the head of screw 26 as the hinge arm member 16 is moved in the direction of double arrow A relative to carrier member 10 and as the assembly of hinge arm member 16 and carrier member 10 is moved in the direction of double arrow B relative to fastener member 5. Face 12 associated with groove 11 in member 10 is inclined as indicated in FIGS. 8 and 12 to provide clearance for pivotal movement of tongue 15 about an axis parallel to double arrow B and passing through screw 21. Such movement occurs in response to rotation of screw 26 which moves hinge shaft 2 along the axis designated by double arrow C. The direction of movement depends on direction of rotation of screw 26 relative to threaded hole 25.
In assembling the members of hinge component 1, carrier member 10 is first nested in cavity 8 of fastener member 5 by seating pins 17 and 18 in guide slots 19 and 20 on wall surface 9. Then, screw 21 is partially threaded into hole 24 thereby loosely holding members 5 and 10 together with interruption 30 of the cylindrical wall of member 5 (FIG. 1) aligned with slot 11 in member 10. Tongue 15 of hinge arm member 16, into which screw 26 has been preassembled, is inserted through interruption 30 into sliding engagement with groove 11, slot 23 in the tongue providing clearance for screw 21. Insertion of tongue 15 continues until the slotted head of screw 26 is contained within recess 27 in wall segment 9. After this occurs, screw 21 can be threaded further into hole 24 until adjustment screw 26 is captured in the recess thereby retaining the hinge arm member to both the fastener member and carrier member.
Having preassembled the members, hinge component 1 can be attached to the piece of furniture by forcing fastener member 5 into bore 4 in side wall 3 of the furniture. Even though screw 21 is not as yet fully tightened, the hinge component will be able to absorb the weight of a door when it is attached to the hinge component because of the reaction between tongue 15 and groove 11 which limits relative movement of the hinge arm in the direction of double arrow A and the reaction of pins 17 and 18 in slots 19 and 20 which limit movement of members 10 and 16 in the direction of double arrow B. Before screw 21 is fully tightened into hole 24, hinge shaft 2 can be adjusted to compensate for dimensional tolerances along the three coordinate axes denoted by the double arrows A, B and C. That is to say, the axis of hinge shaft 2 can be moved in the direction of double arrow A, i.e., in a direction parallel to surface 3" of the furniture and perpendicular to end face 3', in the direction of double arrow B (i.e., in a direction parallel to surface 3" and parallel to end face 3'), and also in the direction of double arrow C (i.e., in a direction parallel to end face 3' and perpendicular to surface 3").
When the axis of hinge shaft 2 is properly located, screw 21 is fully tightened thus clamping tongue 15 of hinge arm member 16 between carrier 10 and the inside surface of wall segment 9 of fastener member 5. To assist in holding hinge arm member 16 in its selected position, the inner surface of wall segment 9 adjacent elongated slot 22 through which screw 21 passes is provided with serrations 32 (see FIG. 3). In addition, the portion of the bottom surface of groove 11 in the vicinity of threaded aperture 24 is serrated at 31 (see FIG. 1); and the opposite surfaces of tongue 15 in the vicinity of clearance slot 23 are serrated as shown at 33 and 34. Both serrations 32 and serrations 34, which engage each other, extend in the direction of double arrow A; and serrations 31 which mate with serrations 33, extend in the direction of arrow B.
The length of adjustment screw 26 is chosen to fit entirely within recess 27 and surface 12 as shown in FIGS. 8 and 12. Consequently, the slotted head of screw 26 will seat against the inside surface of recess 27 while the free threaded end of the screw will seat surface 12. After screw 26 is rotated until shaft 2 is in the selected position, further tightening of screw 21 will preclude further rotation of screw 26 thus ensuring stability in the selected attitude of hinge arm shaft 2. Thus, in the hinge component of the present invention, only a single screw is used to interlock all of the members.
As shown in FIGS. 7-14, the hinge component of the present invention permits a considerable displacement of hinge shaft 2 along three mutually perpendicular axes corresponding to double arrows A, B and C. The position of the axis of hinge arm 2 relative to end face 3' of the furniture can be minimized in the manner shown in FIGS. 7-9, by sliding tongue 15 inwardly relative to carrier member 10 as far as possible and by tilting the hinge arm member until it contacts support surface 12 of member 10 as shown in FIG. 8. In this position, the hinge shaft 2 can be moved in the direction of double arrow B by sliding member 10 through the displacement b as indicated in FIG. 9.
FIGS. 11-14 show a setting of hinge arm members 16 by which the hinge is shifted by a maximum amount b in the direction of double arrow B while the hinge shaft 2 is positioned at a maximum distance from end face 3' and from outer surface 3'" of the side wall three of the piece of furniture. The range of adjustment of hinge arm 16 and consequently the adjustment of hinge shaft 2 is enhanced by inclining the inside of surface of wall segment 9 from the region of slot 22 where the thickness of the wall section is a maximum as shown in FIGS. 8 and 12. In addition, the support surfaces of carrier member 10 facing the inside surface of wall segment 9 are likewise inclined as shown in FIGS. 8 and 12 thereby permitting maximum displacement of hinge arm member 16 about an axis passing perpendicularly through screw 21 in a direction parallel to the double arrow B.
In order to limit the depth of penetration of fastener member 5 into the seating bore 4, the member 15 provided with projecting flange 35 (FIG. 1) on the surface of wall segment 9 that is exposed when the fastener is mounted in the side wall piece of furniture. Such flange rests against the inside surface 3" of the side wall 3' of the piece of furniture surrounding bore 4. Flange 35 narrows into a triangular tang containing hole 36 through which an additional anchoring screw 37 can be inserted as shown in FIGS. 8 and 12.
The material for hinge arm member 16 and fastener member 5 is preferably metal. However, a tough plastic can be used to make members 5 and 10.
It is believed that the advantages and improved results furnished by the apparatus of the present invention are apparent from the foregoing description of the several embodiments of the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention as sought to be defined in the claims that follow.
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A hinge component for pivotally connecting two parts of a piece of furniture includes a fastener member adapted to be attached to one part of the furniture, a carrier member mounted in the fastener member for adjustable displacement relative thereto along a first axis, and a hinge arm member which carries a hinge shaft defining the pivotal axis of the hinge component. The hinge arm member is mounted in a guide groove formed in the carrier member for adjustable displacement relative thereto along a second axis perpendicular to the first axis. After the carrier member is adjusted relative to the fastener member, and the hinge arm member is adjusted relative to the carrier member, the hinge arm member can be clamped between the carrier and fastener members. Thereafter, the hinge arm member can be adjustably displaced relative to both the fastener and carrier members along a third axis perpendicular to both the first and second axis thus providing three degrees of freedom for the hinge shaft.
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FIELD OF THE INVENTION
The present invention relates to a method and a device for operating an internal combustion engine.
BACKGROUND INFORMATION
It is already known that the available time for an injection of fuel into a combustion chamber of an internal combustion chamber is limited. In systems where an injection takes place in front of the intake valves of the combustion chamber, the entire injection must be concluded before the individual intake valve closes. The injection for the next aspiration of the cylinder may then begin. In direct gasoline injection, the injection begins after the intake valve has been closed, but must be concluded prior to ignition. The maximum injection duration gets shorter with increasing engine speed. Injection valves are therefore designed such that they are able to discharge the required injection quantity even at maximum rotational speed and full loading of the internal combustion engine. They are tightly configured so that fuel is able to be metered with sufficient precision also at idling speed without loading. Especially in supercharged internal combustion engines, at high engine speed and high loading, an additional enrichment of the air/fuel mixture may be necessary for reasons of component protection. In the described tight configuration of the injection valves, the available time then is insufficient to supply the increased injection quantity for the enrichment. Therefore, methods are known in which the charge of the combustion chamber is reduced by a specific amount by way of an abrupt closing of the throttle valve or via an abrupt lowering of the charge pressure in supercharged engines. If such lowering were not implemented, the supplementary quantity required for the enrichment could not be spray-discharged and the component protection would have no effect.
SUMMARY OF THE INVENTION
In contrast, the method according to the present invention as well as the device for operating an internal combustion engine according to the present invention, have the advantage of ascertaining a maximally possible injection duration for an injection operation of the at least one injection valve, and of limiting a variable characterizing the output of the internal combustion engine by a corresponding adjustment of the at least one actuator as a function of the maximally possible injection duration. This ensures compliance with the maximally possible injection duration without sudden drop in the output of the internal combustion engine at full load and with a required enrichment of the air/fuel-mixture ratio, for instance. In this manner a steady limiting of the output of the internal combustion engine is able to be implemented once a maximally possible injection duration of an injection valve has been reached.
It is particularly advantageous if a maximally possible air charge in a combustion chamber ( 20 ) of internal combustion engine ( 1 ) is ascertained as a function of the maximally possible injection duration and a predefined air/fuel mixture ratio as a variable characterizing the output of internal combustion engine ( 1 ), and if the setting of the at least one actuator ( 5 , 10 ) is limited as a function of the maximally possible air charge. This prevents an abrupt reduction of the charge, and a steady limiting of the charge is able to be realized instead. In an advantageous manner, the predefined air/fuel mixture ratio may already take into account an enrichment that may be required for reasons of component protection, thereby increasing the driving comfort.
It is especially advantageous if the maximally possible injection duration is ascertained as a function of the instantaneous state of the internal combustion engine, in particular from an instantaneous value of an engine speed of the internal combustion engine. In this manner, in anticipation of a full-load operating state, it is possible to specify a restriction of the air supply in a partial-load operating state already, in such a way that the maximally possible injection duration is still sufficient to realize the predefined air/fuel mixture. Abrupt shifts to lower torques in the full-load range, which interfere with driving comfort, are avoided in this manner. On the other hand, the air supply is restricted to the absolutely necessary minimum.
In an advantageous manner, the air supply may be influenced via a throttle-valve control, which triggers a first actuator to control the air supply. With the aid of this first actuator, in particular a throttle valve, the air supply may be reduced relatively quickly if the throttle valve is controlled in the closing direction.
The air supply may also be influenced in an advantageous manner via a possibly provided charge-pressure control, which triggers a second actuator to control the air supply. With the aid of this second actuator, especially a bypass around a turbine of an exhaust turbocharger, or by means of a variable turbine geometry, the air supply is able to be reduced relatively slowly if the bypass is controlled in the opening direction or if the variable turbine geometry is triggered for the opening of the guide blades.
It is particularly advantageous if both the first actuator and the second actuator are available and the charge is reduced more rapidly via the first actuator and lowered more slowly via the second actuator, and if the second actuator activates the first actuator again in the opening direction upon reduction of the charge. This allows the fuel consumption to be reduced.
In addition, it is advantageous if a driving pedal of a vehicle driven by the internal combustion engine is scaled as a function of the maximally possible air charge. This makes it possible, especially at full loading, to avoid an abrupt reduction of the charge of the internal combustion engine assigned to the driving-pedal position so as to realize an enrichment of the air/fuel mixture for the described component protection. As a result, a charge of the internal combustion engine may be assigned to the particular driving-pedal position in an unambiguous manner, such charge also not changing abruptly at an identical driving-pedal position, so that the driving comfort is increased.
Another advantage results if the maximally possible air charge is converted into a maximally possible output variable of the internal combustion engine, in particular into a maximally possible torque, and if a maximally possible position of the driving pedal is assigned to this maximally possible output variable. In anticipation of the full-load operating state of the internal combustion engine, the driver wish ascertained via the driving-pedal position may thus be limited to a value of the output variable, especially a torque, at which the maximally possible injection duration of the at least one injection valve is still sufficient to implement this driver wish, such limiting already being implemented in a partial-load operating state of the internal combustion engine. This avoids abrupt switches to lower values for the output variable, in particular to lower torques, in the full-load operating state of the internal combustion engine, which are disruptive. On the other hand, the lowering of the output variable, in particular the torque, is limited to the absolutely minimum, since this lowering conforms exactly to the maximally possible injection duration, which is not the case in the abrupt lowering according to the related art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of an internal combustion engine.
FIG. 2 shows a flow chart to elucidate the method according to the present invention and the device according to the present invention.
DETAILED DESCRIPTION
Reference number 1 in FIG. 1 denotes an internal combustion engine having a combustion engine 125 such as a spark-ignition engine. Internal combustion engine 1 may drive a motor vehicle, for instance. In this example, combustion engine 125 includes one or several cylinders of which one, bearing reference numeral 130 , is shown in FIG. 1 by way of example. Fresh air is able to be supplied to a combustion chamber 20 of cylinder 130 via an air feed 75 and an injection valve 85 . A throttle valve 5 , which adjusts the air supply to combustion chamber 20 of cylinder 130 , is disposed in air feed 75 . Via an engine control 40 , throttle valve 5 is controlled to adjust a predefined opening degree, which engine control 40 ascertains as a function of a position of a driving pedal 35 in order to convert a driver wish corresponding to the driving-pedal position in the manner known to one skilled in the art. According to the example described in FIG. 1 , an injector 15 injects fuel into air feed 75 between throttle valve 5 and intake valve 85 . This section of air feed 75 is also known as intake manifold. As an alternative, the fuel could also be injected directly into combustion chamber 20 of cylinder 130 with the aid of a fuel injector. The fuel quantity to be injected is adjustable via an instant for the injection start and an injection duration, given a constant and known injection pressure. In the process, engine control 40 specifies the instant for the beginning of the injection and for the injection duration as a function of an oxygen concentration in the exhaust gas, in such a way that a predefined air/fuel mixture ratio is adjusted. The air/fuel mixture arriving in combustion chamber 20 of cylinder 130 is ignited by a spark plug 90 whose ignition instant is likewise specified by engine control 40 as a function of the operating state of internal combustion engine 1 and in a manner known to one skilled in the art. The combustion of the air/fuel mixture in combustion chamber 20 drives a piston 120 of cylinder 130 , this piston 120 driving a crankshaft (not shown in FIG. 1 ) whose rotational speed is recorded by an engine-speed sensor 100 and forwarded to engine control 40 . The exhaust gas generated in combustion chamber 20 of cylinder 130 during combustion of the air/fuel mixture is expelled into an exhaust tract 110 of internal combustion engine 1 via a discharge valve 95 . Intake valve 85 and discharge valve 95 may be opened and closed in a known manner via engine control 40 as shown in FIG. 1 , or via one or several camshafts. As an alternative, which is illustrated in FIG. 1 in the form of a dotted line, an exhaust-gas turbocharger may be provided whose turbine 105 in exhaust tract 110 is driven by the exhaust-gas mass flow. Via a shaft 115 , the turbine motion is transmitted to a compressor 80 in air feed 75 , which in this manner compresses the air supplied to combustion chamber 20 of cylinder 130 . The compressor output or the charge pressure of the exhaust-gas turbocharger may be influenced via an actuator 10 . Actuator 10 may be embodied, for instance, as bypass valve in a bypass which guides the exhaust-gas mass flow past turbine 105 . The opening degree of the bypass valve determines the portion of the exhaust-gas mass flow that is guided past turbine 105 and will not contribute to the compressor output. As an alternative, in the case of an exhaust-gas turbocharger having variable turbine geometry, actuator 10 may influence the compressor output, and thus the charge pressure, also by adjustment of the guide blades of turbine 105 . Actuator 10 , too, is controlled by engine control 40 to achieve the desired compressor output or the desired charge pressure. According to FIG. 1 , compressor 80 is disposed in the flow direction of the fresh air in front of throttle valve 5 , the flow direction being marked by an arrow. The output of internal combustion engine 1 may be influenced by varying the setting of throttle valve 5 and/or actuator 10 .
As described, the time available for an injection of fuel into a combustion chamber of an internal combustion engine is limited. In systems with an injection in front of the intake valves of the combustion chamber, as shown in FIG. 1 for one cylinder by way of example, the entire injection must be completed before individual intake valve 85 closes. The injection for the next aspiration of cylinder 130 may then begin. In gasoline direct injection, the injection begins after intake valve 85 has been closed, but must be completed prior to ignition. The maximum injection duration gets shorter with increasing engine speed. For that reason, injection valves are designed such that they are still able to discharge the required injection quantity at maximum rotational speed and full loading of the internal combustion engine. They are tightly configured so that fuel is able be metered with sufficient precision at idling speed without loading as well. Especially in the case of supercharged internal combustion engines an enrichment of the air/fuel mixture may become necessary at high engine speed and high loading for reasons of component protection. Given the described tight tolerances of the injection valves, the available time is then insufficient to discharge the increased injection quantity for the enrichment.
For that reason, according to the present invention, the maximally possible injection duration for an injection operation of the at least one injection valve 15 is ascertained first. A variable characterizing the output of internal combustion engine 1 is limited as a function of the maximally possible injection duration by appropriate adjustment of throttle valve 5 and/or actuator 10 . This ensures compliance with the maximally possible injection duration without sudden drop in the output of the internal combustion engine at full load, for instance, and with a required enrichment of the air/fuel mixture ratio.
In particular, it is then possible to ascertain, as a function of the maximally possible injection duration and a predefined air/fuel mixture ratio, a maximally possible air charge of combustion chamber 20 as a variable characterizing the output of internal combustion engine 1 , and to limit the setting of throttle valve 5 and/or actuator 10 as a function of the maximally possible air charge. In this way, the maximally possible air charge may be restricted from the beginning, namely to such an extent that the maximally possible injection duration is unable to be exceeded, with the result that an enrichment of the air/fuel mixture possibly required in the full-load operating state of internal combustion engine 1 , will not require an abrupt reduction of the air charge. The air/fuel mixture ratio predefined for the purpose of ascertaining the maximally possible air charge of combustion chamber 20 should be selected such that an enrichment required for component protection, for instance, already is taken into account.
The maximally possible injection duration may be determined in an advantageous manner as a function of the current operating state of internal combustion engine 1 . In this way, it is possible, already in an instantaneous operating state corresponding to a partial-load operating state, to ascertain the maximally possible air charge for a full-load operating state on the basis of this instantaneous partial-load operating state; this allows the maximally possible air charge to be limited in an anticipatory manner to a value at which the maximally possible injection duration will still be sufficient to implement the predefined air-fuel mixture ratio. In such a manner, a distracting abrupt reduction of the air charge in the full-load range is avoided. In addition, it is ensured that in such a full-load operating state the maximally possible air charge will also be available and will not be undershot by a return jump of the air charge determined independently of the maximally possible injection duration.
The maximally possible air charge will then be the input signal for a throttle-valve control and/or a charge-pressure control (if available). If, for the purpose of limiting the air charge to the maximally possible air charge determined as a function of the maximally possible injection duration and the specified air/fuel-mixture ratio, the air charge needs to be lowered, this may be implemented more rapidly if throttle valve 5 rather than actuator 10 is used for a charge-pressure reduction, and thus a charge reduction. If both the throttle-valve control and the charge-pressure control are available, such a reduction in the air charge may be implemented both by corresponding control of throttle valve 5 and corresponding control of actuator 10 , the reduction of the charge with the aid of throttle valve 5 being faster than the reduction of the charge pressure. As soon as the slower charge-pressure reduction has a noticeable effect on the charge reduction, throttle valve 5 may once again be moved in the opening direction so as to reduce the fuel consumption.
Furthermore, it may be provided that the maximally possible air charge be converted into a maximally possible value of an output variable of internal combustion engine 1 , in particular a maximally possible torque, and be entered in a scaling of driving pedal 35 in which the driver wish, expressed by the driving-pedal position, is scaled such that the maximally possible value for the output variable ascertained in this manner—in this case for the torque—is assigned to the maximum driving-pedal position. In this way, the torque corresponding to the driver wish, hereinafter also called driver-desired torque, may be limited already in a partial-load operating state of internal combustion engine 1 , in an anticipatory manner, to the maximally possible torque at which the injection duration is still sufficient to adjust the predefined air/fuel-mixture ratio. As described earlier for the air charge, this increases the driving comfort since distracting abrupt shifts to lower torques in the full-load range are avoided. On the other hand, the possibly required reduction of the torque is restricted to the absolutely minimum. As an alternative to the torque, a power output or some other variable derived from the torque and/or the power output may be used as output variable. The output variable, too, thus represents a variable characterizing the output of internal combustion engine 1 , which is limited by an appropriate setting of throttle valve 5 and/or actuator 10 in order to maintain the maximally possible injection duration.
On the basis of the flow chart shown in FIG. 2 , the sequence of the method according to the present invention will be explained in the following; the flow chart may be implemented in engine control 40 in the form of software and/or hardware. In the intake-manifold injection illustrated in FIG. 1 , dimensionless constant KTI corresponds to the maximally possible injection duration up to the time when intake valve 85 is closed, given one rotation of the crankshaft per minute and thus an engine speed of 1/minute. Constant KTI is predefined and known in engine control 40 . It may be ascertained on a test stand, for instance. In a first division element 45 constant KTI is divided by current engine speed nmot [rotations/minute], the current engine speed nmot being ascertained by engine-speed sensor 100 . At the output of first division element 45 , this will result in the maximally possible injection duration timax for current engine speed nmot as
ti max= KTI/n mot (1).
Maximally possible injection duration timax for instantaneous engine speed nmot is then reduced in a subtraction element 50 by a pick-up delay correction time tvub. Pick-up delay correction time tvub is the time that elapses from the triggering of injection valve 15 until the complete opening of injection valve 15 . Pick-up delay correction time tvub may also be ascertained on a test stand, for instance. By subtracting pick-up delay correction time tvub from maximally possible injection duration timax, a maximally possible effective injection time temax results at the output of subtraction element 50 as
te max= ti max− tvub (2).
Also stored in engine control 40 is a flow-rate constant KEV of injection valve 15 , which is likewise ascertainable on a test stand, for example, or which is specified by the manufacturer and describes in what time period a known predefined standardized fuel mass is spray-discharged. If one divides maximally possible effective injection duration temax by flow-rate constant KEV in a second division element 55 , one obtains a maximally possible relative fuel charge rkmaxPO of combustion chamber 20 , which is related to the standardized fuel mass and results at a predefined known standard pressure in the fuel system. The fuel system includes the fuel pump and the fuel-supply line to injector valve 15 , which are not illustrated in FIG. 1 . Maximally possible relative fuel charge rkrmaxPO thus results as
rk max PO=te max/KEV (3).
Maximally possible relative fuel charge rkmaxPO has the dimension of a mass and will then be divided in a third division element 60 by a dimensionless correction factor fkkd for the actual fuel pressure. The actual fuel pressure is able to be ascertained by a fuel pressure sensor in the region of injection valve 15 , such a fuel pressure sensor not being shown in FIG. 1 for reasons of clarity. In systems without fuel-pressure sensor, the described correction will not be possible. In this way the actual fuel pressure is taken into account. The correlation between the measured fuel pressure and dimensionless correction factor tkkd with respect to the relative fuel charge may be ascertained on a test stand, for instance.
Resulting at the output of third division element 60 thus is maximally possible relative fuel charge rkmax, which considers the actual fuel pressure, as
rk max= rk max PO/fkkd (4).
Maximally possible relative fuel charge rkmax, which takes the actual fuel pressure into account, is then divided in a fourth division element 65 by predefined (dimensionless) air/fuel-mixture ratio Lams, the so-called lambda value. The predefined air/fuel-mixture ratio may already consider an enrichment for the purpose of component protection. Resulting at the output of fourth division element 65 therefore is maximally possible air charge rlmaxti of combustion chamber 20 at which the required fuel mass is also able to be spray-discharged and which is associated with maximally possible relative fuel charge rkmax that takes the actual fuel pressure into account. Maximally possible air charge rlmaxti of combustion chamber 20 thus results at the output of fourth division element 65 as
rl max ti=rk max/Lams (5).
Maximally possible relative air charge rlmaxti is entered into throttle-valve control 25 and limits the setpoint charge from which the associated throttle-valve angle is calculated in throttle-valve control 25 . In the event that a charge-pressure control 30 is present, as indicated in the exemplary embodiment according to FIG. 1 by the exhaust-gas turbocharger denoted by the dashed line, maximally possible relative air charge rlmaxti may also be input variable of charge-pressure control 30 where it also restricts the setpoint charge from which the setpoint charge pressure for the triggering of actuator 10 is calculated. Furthermore, maximally possible relative air charge rlmaxti may be input variable of a driver-pedal scaling 70 where it restricts the driver-desired torque to a maximally possible torque derived from maximally possible relative air charge rlmaxti, the maximally possible torque being used to implement the driver-pedal scaling, i.e., the maximally possible driver-pedal position is assigned to this maximally possible torque. The derivation of the maximally possible torque from maximally possible relative air charge rlmaxti is carried out in a manner known to one skilled in the art. The maximally possible driver-pedal position is thus matched to the current maximally possible torque.
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A method and a device for operating an internal combustion engine are provided, which allow a continuous limiting of the output of the internal combustion engine upon attaining a maximally possible injection duration of an injection valve. The internal combustion engine has at least one actuator for influencing the output of the internal combustion engine and at least one injection valve for supplying fuel to the combustion engine. A maximally possible injection duration for an injection procedure of the at least one injection valve is determined. A variable characterizing the output of internal combustion engine is limited as a function of the maximally possible injection duration by corresponding adjustment of the at least one actuator.
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BACKGROUND OF THE INVENTION
Garage door operators have been conceived and constructed for over 40 years. The concept of a longitudinally stationary but rotating screw to act on a traveling nut to open an overhead-type garage door was shown to be conceived nearly 45 years ago by U.S. Pat. No. 2,056,174. Cable-operated or chain-operated garage door operators have also been proposed, for example, as shown by U.S. Pat. Nos. 3,439,727 and 3,444,650. Typically, garage door operators are ones which have a traverse of the door operator mechanism of about eight or nine feet in order to accommodate the usual garage door plus the 90-degree angle through which the door turns. In the chain-type of garage door operator that has been manufactured, it has been customary for many years to shorten the package in which the door operator is shipped by cutting the guide channel into two or three parts which may be spliced together. Thus, the channel which was previously nine feet long now comprises three parts of about three feet in length. However, the screw drive door operators which have been marketed for many years have retained a one-piece screw and a one-piece guide means of about nine feet in length, which makes the package costs higher and, more importantly, makes the shipping and storage costs higher because the shipping charges are usually based upon the cubic volume rather than on the weight.
Recently, there has appeared on the market a screw drive garage door operator wherein the guide means is in two parts and the screw is in two parts and interconnected by coupling means which has an interconnecting link with a pivot pin at each end pivoted to the two screw parts. The guide means and screw parts are folded for shipment and then, upon installation, are straightened to be coaxial, and splice plates are bolted onto the sides of the guide means to maintain the coaxial alignment of the screw parts. A problem with such construction is the weakness of this coupling relative to the rest of the screw, the problem of providing a properly straightened guide means, and the problem of whipping of the screw during rotation which, because of two different pivot points, acts somewhat like a universal joint to whip around inside the guide means.
More importantly, the coupling for the two screw parts has so many different parts that the possible cumulative error in the tolerance of all these manufactured parts can make it possible that the threads on the two screw parts will be mismatched relative to the traversing partial nut, and thus the nut will fail to traverse this elongated coupling. Also, the very many parts in such coupling means and the necessary clearance between the parts in order to fold means that the coupling will tend to destroy itself upon repeated reversals of the screw. In practically all screw drive garage door openers, the motor reverses each time it is started, first driving the screw clockwise and then driving it counterclockwise in order that the nut traverses forward and then in reverse for closing and opening directions of the garage door. This continual reversing of torque through the coupling and the looseness or "play" in all the parts will tend to batter the coupling apart and make the clearance of the parts even greater, which will therefore create the great possibility of mismatch of the threads in the future during life of the operator, if they are not mismatched at the time of initial assembly.
SUMMARY OF THE INVENTION
This problem is solved by a garage door operator having a motor-driven screw at least partially within guide means, a partial nut guided by said guide means and movable longitudinally therealong by engagement with said screw and connectable to open and close the garage door, the screw being in at least first and second parts, and a coupling adapted to interconnect adjacent ends of the first and second screw parts, the improvement comprising said coupling being readily connectable and being disconnected at the time of shipment to the customer.
Accordingly, an object of the invention is to provide a door operator screw coupling with a minimum of parts, and hence with a minimum possible cumulative tolerance.
Another object of the invention is to provide a door operator screw coupling wherein the coupling includes first and second hermaphroditic parts which are mutually interengageable in only one possible way to preclude mismatch of the threads from the screw parts upon attempted traversal by the partial nut.
Another object of the invention is to provide a simple and effective door operator screw coupling with a long life and a good torque transmittal capability.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view, partly schematic, illustrating the invention;
FIG. 2 is an enlarged, side elevational view of the door operator screw coupling;
FIG. 3 is an enlarged, sectional view on line 3--3 of FIG. 1, to the same scale as FIG. 2;
FIG. 4 is a sectional view on line 4--4 of FIG. 2;
FIG. 5 is an enlarged, partial elevational view of the screw coupling of FIG. 2 assembled; and
FIG. 6 is an enlarged, partial elevational view of a modified door operator screw coupling.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawing illustrates a garage door operator 10 which incorporates the screw coupling 11 of the invention. The garage door operator is intended to be installed within a garage having a ceiling 12 and a door header 13. The operator 10 may open and close almost any type of an enclosure, including slab doors, which can be pivoted or operate on a form of a track. However, a sectional door 14 is illustrated which has sections hinged together and provided with rollers 15 to roll on a track 16 between the closed position shown and an open position near the ceiling 12. The door operator 10 includes a motor 17 having a stator 18 and a rotor 19, rather schematically shown in FIG. 1. The motor 17 is connected to drive a screw 20 having first and second screw parts 21 and 22, respectively. The motor 17 has a shaft 23 connected to rotate the screw 20, and this shaft 23 has bearings, including thrust bearings 24, to absorb the longitudinal thrust in both directions on the screw 20.
The screw is mounted at least partially within guide means 28, and this guide means has a generally cylindrical bore 29 circumscribing about 300 degrees of the screw 20. In the remaining approximately 60 degrees of the periphery of the screw 20, a partial nut 30 is disposed, which nut has a length sufficient to bridge across the length of the screw coupling 11, which is formed of first and second coupling parts 31 and 32, respectively. The guide means 28 provides a guide not only for the screw 20, but also for the nut 30. A slide 34 has wings 35 slidably disposed in grooves 36 in the guide means 28, and this slide 34 carries the partial nut 30. A door arm 37 is pivotally connected at 38 to the slide 34, and at 39 to the door 14. Accordingly, as the motor 17 rotates the screw 20 in either a clockwise or counterclockwise direction, the partial nut 30, engaged with the screw 20, traverses the guide means 28 longitudinally to open or close the garage door 14.
The screw coupling 11 is better illustrated in FIGS. 2, 4, and 5, and the first and second coupling parts 31 and 32 are hermaphroditic parts wherein the first part 31 has a male extension 41 and a female shoulder 43, and the second coupling part 32 has a male extension 42 and a female shoulder 44. The male extension 41 has a male shoulder or forwardly facing shoulder 45, and similarly, the male extension 42 has a male shoulder or forwardly facing shoulder 46. In the embodiment of FIGS. 2, 4, and 5, the coupling parts 31 and 32, when interengaged as shown in FIG. 5, form a reduced diameter portion of the screw 20. The male extension 42 is extended from a reduced diameter portion 49 of the second screw part 22. It is reduced in diameter in order to accommodate the I.D. of a sleeve 50 and also to accommodate the I.D. of a C-clip 51. The male extension 41 is formed of a first flat portion 53 and a second flat portion 54 interconnected by a rear facing or proximal facing shoulder 55. Similarly, the male extension 42 is provided with a third flat portion 57 and a fourth flat portion 58 interconnected by a rear facing or proximal facing shoulder 59. In this preferred embodiment, the flat portions 53, 54, 57, and 58 are parallel to the axis 60 of the screw 20, and the shoulders 55 and 59 are perpendicular to this axis. The flat portion 53 is disposed on one side of the axis 60 approximately the same distance that the flat portion 54 is disposed on the other side of this axis.
The guide means 28 is provided in two parts 64 and 65, which are shown misaligned in FIG. 2 but may be aligned after the screw coupling 11 is interconnected, and then splice plates 66, only one of which is shown in FIG. 2, may be provided one on each side of the guide means 28 and fastened with bolts 67 extending through apertures 68 to secure together the two parts of the guide means 28 in alignment.
OPERATION
The garage door operator 10 is one which has the screw 20 in at least two parts 21 and 22, and the guide means 28 in at least two parts 64 and 65 during shipment. This is in order to reduce the overall length of the package in which the door operator is shipped. Since the shipping costs are based primarily on the cubic volume rather than the weight, the length of the package can be reduced to approximately half if the screw and guide are in two parts, or can be reduced to approximately one-third if the screw and guide are in three parts. This not only saves shipping charges, but saves storage charges, because door operators can be packed, shipped, and stored in a much smaller volume of space. This is of benefit to the distributor as well as the dealer. It is also of benefit to the ultimate customer because the prior art system using an elongated screw of nine to ten feet in length, and a similar length package, could not be brought home in the trunk of an automobile by an ordinary purchaser. If the length is reduced to three and a half or five feet, however, then such transport by the ultimate user is greatly facilitated.
As shipped, the two parts of the screw 21 and 22 preferably extend outwardly from the respective parts 64 and 65 of the guide means, approximately as shown in FIG. 2. The sleeve 50 is first slipped over the male extension 42 onto the reduced diameter portion 49. The two screw coupling parts 31 and 32 are then disposed side-by-side and axially parallel about as shown in FIG. 2. Next, the guide parts 64 and 65 are moved to be coaxial to interengage the coupling parts 31 and 32. By such movement, the first flat portion 53 engages the fourth flat portion 58 and the second flat portion 54 engages the third flat portion 57. Next, the sleeve 50 may be slid to the right as viewed in FIG. 5, and the C-clip 51 transversely inserted over the reduced diameter portion 49. This prevents the sleeve 50 from moving to the left whereat it would not be covering the interengaged coupling parts 31 and 32.
Next, the guide parts 64 and 65 may be axially moved together, sliding over the screw 20, and then the splice plates 66 bolted in place, using the bolts 67 through the apertures 68. The door operator 10 may then be installed against the ceiling 12 and door header 13 in the usual manner, and connected to the door 14 to move it between open and closed positions.
FIG. 6
FIG. 6 shows a modified screw coupling 71 which may replace the screw coupling 11. This screw coupling 71 has first and second coupling parts 81 and 82, respectively, which are hermaphroditic parts in that the coupling part 81 includes a male extension 91 and a female shoulder 93, and the second coupling part 82 includes a male extension 92 and a female shoulder 94. A male shoulder 95 is provided on the end of the male extension 91 and a male shoulder 96 is provided on the end of the male extension 92. The first coupling part 81 is unitary with the first screw part 21, and the second coupling part 82 is unitary with the second screw part 22. These screw parts are again rotatably guided within the guide parts 64 and 65, respectively. In a manner similar to that in the first screw coupling 11, the first coupling part 81 is provided with first and second flat portions 103 and 104 interconnected by a rearwardly facing or proximal facing shoulder 105. Also, the second coupling part 82 is provided with a third flat portion 107 and a fourth flat portion 108 interconnected by a rearwardly facing or proximal facing shoulder 109. Just as in FIGS. 2 to 5, the flat portion 103 is disposed a small distance on one side of the axis 60 and the flat portion 104 is disposed substantially the same distance on the other side of this axis 60. The flat portions 103, 104, 107, and 108 are preferably parallel to the axis 60, and the shoulders 105 and 109, along with the shoulders 93-96, are substantially perpendicular to this axis.
OPERATION
The door operator 10, whether equipped with the screw coupling 11 or 71, is shipped in a collapsed condition, i.e., with the two screw parts 21 and 22 disposed side-by-side within the respective guide means 64 and 65. Upon unpacking, the user or the installer first positions the guide means 64 and 65 about as shown in FIG. 2. The screw part 21 can already be properly in working connection to the motor 17. In the position of FIG. 2 or 6, the axes of the two screw parts are parallel, but misaligned. Next, the two guide means 64 and 65 are relatively moved transversely to have the flat portion 103 engage the flat portion 108 and to have the flat portion 104 engage the flat portion 107. This interengages the screw coupling 71 and then the two guide parts 64 and 65 may be relatively axially moved together, sliding over the screw 20. With the screw part 21 in operative connection with the motor 17, this will mean that the guide part 65 slides to the right, while screw part 22 remains stationary until the guide part 65 abuts guide part 64. At this time, the splice plates 66 may be bolted in place, as in FIGS. 2 and 3. The door operator 10 may then be mounted to the ceiling 12 and door header 13 in the usual manner.
The screw couplings 11 and 71 of the present invention are ones where it is not possible to put the two screw parts together in incorrect phase. A triple thread screw has been illustrated in the figures, and in such case it is quite important that the phase of each of the two screw parts 21 and 22 at the coupling 11 or 71 be proper so that they are not mismatched relative to the partial nut 30, which will have to traverse this coupling once for each door opening or closing movement. Because the couplings 11 or 71 are hermaphroditic couplings, i.e., couplings which have partly male and partly female properties, it is impossible to put these couplings together in other than the correct manner. Still further, the way in which the two coupling parts interconnect minimizes the possible cumulative tolerance errors which are inherent in machining the coupling parts.
A two-piece screw for a garage door operator which is currently on the market utilizes a multipart coupling. This screw coupling has a fork on the two adjacent ends of the screws and then an intermediate link is pivoted at each end within these two forks. This makes a type of a universal joint connection so that the two pivot points are far enough apart that the screw may be folded back upon itself, while within the guide parts, without interference between the two guide parts. This makes a long screw coupling and one which has many parts, the cumulative tolerance of which may be excessive and may result in mismatch of the threads on the screw relative to the threads on the partial nut. The possible cumulative tolerance errors, in the longitudinal dimension, in such unit now on the market are: (1) the jig or fixture to hold the first screw at the correct axial position, (2) the diameter of the hole in the first fork, (3) the diameter of the hole in the first tongue, (4) the axial position of the hole in the first fork, (5) the dimension between the two pivot holes in the intermediate link, (6) the axial position of the hole in the second fork, (7) the diameter of the hole in the second tongue, (8) the diameter of the hole in the second fork, and (9) the jig or fixture to hold the second screw at the correct axial position. These are all things which will affect the axial dimension, and hence proper phase match, of the threads on the two screw parts relative to that on the nut. Additionally, there are other tolerances which affect the rotational position of one screw relative to the other, but these will be disregarded as being of lesser importance than the cumulative tolerance on the axial position. If each of the above nine dimensions is held to plus or minus 0.002 inch in tolerance, then this is a total of nine times 0.004 inch, or 0.036 inch possible cumulative tolerance. This is about half the width of the crest of the square thread on the screw. These screw drive door operators are ones which typically reverse the direction of rotation of the screw each time the motor is started. That means the screw will rotate clockwise, for example, for door opening, and counterclockwise for door closing. This continuous reversal of rotation means that first there is an axial compression force on the coupling and next an axial tension force on the coupling. This results in continual battering of the coupling so that the dimensional tolerances will increase from that occurring at the time of manufacture. The stress and shock on the coupling are perhaps worst in the initial acceleration from rest of a 200 or 300 pound door, to overcome the inertia of such door. Even if mismatch of the threads on the nut with that on the two screw parts does not occur at the time of manufacture, there is increasing likelihood that the screw threads will become mismatched sometime during use of the door operator.
The present invention teaches the structure of the screw coupling 11 or 71 which minimizes such possible cumulative tolerance error. In order to compare the present invention with the door operator existing on the market, the present invention has the following possible cumulative tolerance errors:
(1) the axial phase position of the end of the thread on the first screw part 21 to the female shoulder 43 or 93;
(2) the axial dimension of the flat portion 54 or 104;
(3) the axial dimension of the flat portion 53 or 103;
(4) the axial dimension of the flat portion 57 or 107;
(5) the axial dimension of the flat portion 58 or 108;
and
(6) the axial dimension between the female shoulder 44 or 94 and the same phase position of the thread on the second screw part 22.
At first, this appears that there is only a 9:6 or 3:2 improvement in the possible cumulative tolerance error. However, it will be noted that the first and second coupling parts 31 and 32 or 81 and 82 interfit, and this eliminates two of the possible cumulative tolerance errors. For example, suppose that the length of the first flat portion 53 fits closely relative to the first or flat portion 58, and more closely than the two flat portions 54 and 57 interfit, then it will be the shoulders 44 and 45 which take the axial compression force rather than shoulders 43 and 46. Shoulders 55 and 59, of course, take the axial tension force. This means that it is only the possible tolerance error on the length of the first flat portion 53 which is of importance out of all of the four lengths of flat portions, plus the first and sixth on the list immediately above for a total of three possible tolerance dimensions. If each of these is established at plus or minus 0.002 inch, as in the example given above, then this will be three times 0.004 inch, or 0.012 inch possible cumulative tolerance. This is three times better than the unit currently on the market, and shows the advantage of the hermaphroditic interfitting coupling 11 or 71.
The coupling 11 shown in FIGS. 2 to 5 incorporates the sleeve 50, which is closely received on the two interfitting male extensions 41 and 42. This sleeve 50, then, helps absorb the clockwise or counterclockwise torque transmitted by the first screw part 21 to the second screw part 22. The load of the door 14 on the motor 17, and especially the starting and stopping acceleration and deceleration forces, tend to split apart the two coupling parts 31 and 32. The sleeve 50 may be a hardened steel sleeve to resist such torque-caused separation. In the screw coupling 71, there is the same type of torque-caused tendency to spread apart the two coupling parts 81 and 82. In this design, this tendency is resisted by the guide means 28, which, in the preferred embodiment, is a heavy-walled aluminum extrusion circumscribing about 300 degrees of the periphery of the screw 20. The screw coupling 71 has the advantage of threads along the entire outer periphery of the coupling, so that the partial nut rides easily along the matched threads at this coupling. In the screw coupling 11 of FIGS. 2 to 5, the length of the coupling 11 between threads, assembled as shown in FIG. 5, is only about 0.75 inch, including the reduced diameter portion 49, for a pitch diameter of the screw of about 0.5 inch, and the partial nut may have a length of about 2.6 inches in a typical door operator, so such partial nut easily spans this 0.75 inch screw coupling 11 whereat there are no external threads. Of course, the reduced diameter portion 49 is reduced to a diameter to permit the sleeve 50 to be mounted yet to have the outside diameter thereof below the root diameter of the thread forms on the screw 20.
The above descriptions of the screw couplings 11 or 71 show a coupling which is readily connectible by the user or installer, yet it is disconnected at the time of shipment to the ultimate customer. Phase means are provided so that the couplings are mutually interengageable in only one possible manner, and this precludes interconnecting these screw parts in an incorrect phase of the threads on the screw parts. The phase means is provided by the hermaphroditic style of coupling. The interconnecting male and female shoulders 44 and 45, for example, provide direct transfer of longitudinal compression force therebetween. This eliminates any whipping action which may be caused by the double pivoted screw coupling of the prior marketed unit. The interconnected rearwardly facing shoulders 55 and 59, or 105 and 109, directly transmit longitudinal tension forces therebetween, which would be the case for door opening movement. The two couplings 11 and 71 illustrate ways in which a part of the first screw directly engages a part of the second screw for directly transmitting torque both clockwise and counterclockwise between the screw parts.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.
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A garage door operator is disclosed which has a motor-driven screw nearly enclosed within a guide, and a partial nut is guided by this guide means and moved longitudinally therealong by engagement with the rotating screw. The partial nut is adapted to be connected to a garage door to open and close the same. In order to shorten the package in which the garage door opener is shipped, the screw and guide means are in two or more parts and adapted to be coupled together to make an operative long screw and an operative long guide means. The screw parts, instead of being connected together at the factory by a double pivot connection, are shipped to the customer in a disconnected condition but one in which the coupling readily may be connected in a proper phase to avoid mismatch of the threads. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.
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FIELD
This invention relates to a turbo pump for a vehicle engine, and in particular to an exhaust driven turbo pump incorporating a turbocharger. Aspects of the invention relate to a pump, to an assembly, to a system, to an engine and to a vehicle.
BACKGROUND
Exhaust driven turbochargers for vehicle engines are well known. A turbine of the turbocharger driven by exhaust gas, drives a compressor on the inlet side, and thereby increases the charge volume of each combustion cycle of the engine.
Also known is the technique of exhaust gas recirculation (EGR), whereby exhaust gas is re-circulated to the inlet side of the engine to dilute the fresh air charge during a cold engine start for the purpose of reducing noxious emissions.
High pressure EGR provides exhaust gas from at or adjacent the exhaust manifold. This arrangement is somewhat disadvantageous since the exhaust gas stream is hot, and thereby increases the temperature of the inlet charge upon mixing therewith. Also such exhaust gas is unfiltered, and thus contains carbon and other contaminants which may cause deterioration of engine lubricant.
So-called low pressure EGR is an alternative which provides exhaust gas from a point in the exhaust system downstream of the usual diesel oxidation catalyst (DOC) and diesel particle filter (DPF). Such gas is relatively cool and clean, but is substantially at tail pipe pressure. The consequence of relatively low pressure is that insufficient volume may flow, or be drawn, into the engine inlet tract. A pump may thus be provided to ensure that a sufficient volume of relatively cool and clean exhaust gas can be provided to the inlet tract on demand.
SUMMARY OF THE INVENTION
It is against this background that the present invention has been conceived. Embodiments of the invention may provide an improved pump that addresses the above issues. Other aims and advantages of the invention will become apparent from the following description, claims and drawings.
According to one aspect of the present invention there is provided an exhaust turbo pump assembly of a vehicle engine, and having paired compressor and turbine wheels rotatable about a common axis, an inner pair of said wheels being connected by a tubular shaft rotatable relative to a spindle passing through said shaft and connecting an outer pair of said wheels, one pair of wheels comprising an exhaust driven turbocharger, and another pair of said wheels comprising an exhaust driven turbo pump for exhaust gas re-circulation to the engine inlet tract. Such a pump is referred to herein as an EGR turbo pump.
Such an arrangement may provide a compact turbo pump assembly in which the pairs of compressor and turbine wheels operate independently about the same rotational axis to provide a turbocharger and an EGR turbo pump.
In one embodiment a dual turbo pump assembly is provided. Additional pairs of turbine and compressor wheels may be provided and linked by a respective tubular shaft rotatable on the common axis. For example a triple turbo pump assembly may comprise a two stage turbocharger, and an EGR turbo pump.
In an embodiment of the invention, outer wheels of the turbo pump assembly are annular, the through passages providing gas flow paths to respective inner wheels.
In an embodiment of the invention, the EGR turbo pump is operable on demand, and includes a closure valve upstream of the turbine wheel thereof. The closure valve may be closed, so that active rotation of the turbine wheel of the EGR pump is obviated and all exhaust gas passes through the turbocharger turbine wheel. The closure valve may be opened progressively to provide for increasing flow over the EGR pump turbine wheel, so as to achieve a desired pumping effect from the EGR pump compressor wheel which is paired therewith.
The turbocharger may include a conventional wastegate or the like to avoid overpressure thereof and/or to divert flow which the turbocharger turbine cannot accommodate.
In one embodiment, the turbocharger comprises an inner pair of wheels whereas the EGR turbo pump comprises an outer pair of wheels.
In an embodiment of the invention, the outlet of the compressor wheel of the EGR turbo pump and the outlet of the compressor wheel of the turbocharger are connected. In this arrangement exhaust gas which has been pressurized by the EGR turbo pump mixes with pressurized inlet air from the turbocharger at a location downstream of both compressor wheels.
In another embodiment the outlet of the compressor wheel of the EGR turbo pump and the inlet of the compressor wheel of the turbocharger are connected. In this arrangement a relatively lower pressure of exhaust gas is required for mixing in the inlet tract upstream of the turbocharger compressor wheel.
The compressor wheel of the EGR turbo pump is sized to provide a sufficient flow of re-circulated exhaust gas at the mixing location, and suitable pressure regulators, flow restrictors and/or non-return valves may be provided as required.
In an embodiment of the invention, re-circulated exhaust gas may be provided directly to the inlet tract upstream of the turbocharger compressor and without additional pressurization from the EGR turbo pump. Such an arrangement provides additional options for mixing and distributing exhaust gas to the inlet side of the engine, and may supplement exhaust gas introduced via the EGR turbo pump. Suitable diverter valves and/or flow restrictors may be incorporated to ensure that a desired proportion of exhaust gas flows via the respective paths.
In another embodiment, clean air from the inlet tract of the engine may be introduced into the exhaust gas re-circulation duct upstream of the compressor wheel of the EGR turbo pump. A suitable valve, which may allow flow control, thus permits dilution of re-circulated exhaust gas; this may be useful to achieve a desired proportion of re-circulated exhaust gas in the engine inlet charge.
The thus diluted exhaust gas subsequently passes through the EGR turbo pump compressor wheel and is directed either to the inlet tract upstream of the turbocharger compressor, or to a point downstream of turbocharger compressor and preferably upstream of an intercooler of the engine inlet tract.
In another embodiment a four-way valve may be provided in the exhaust re-circulation duct upstream of the EGR turbo pump compressor. Such a valve comprises an exhaust gas inlet, a fresh air inlet from the inlet tract, an outlet to the inlet tract upstream of the turbocharger compressor, and an outlet to the EGR turbo pump compressor.
In use the four-way valve may be closed, to prevent exhaust gas re-circulation, or may be open to permit one of:
a) direct admission of unpressurized exhaust gas to the inlet tract of the engine; b) direct admission of unpressurized exhaust gas to the EGR turbo pump compressor; c) a combination of a) and b) in a desired proportion; d) dilution of the re-circulated exhaust charge with fresh air from the inlet tract, the combined flow passing to the EGR turbo pump compressor; and e) a combination of a) and d).
The various flow paths provided by embodiments of the invention allow mixing of re-circulated exhaust gas at several locations upstream and downstream of the turbocharger compressor. These variations also permit advantageous mixing of relatively hot and relatively cool gas in proportions which may also achieve a desirable gas temperature profile at locations on the engine inlet side.
Within the scope of this application it is envisaged that the various aspects, embodiments, examples and alternatives, and in particular the individual features thereof, set out in the preceding paragraphs, in the claims and/or in the following description and drawings, may be taken independently or in any combination. For example features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
BRIEF DESCRIPTION OF DRAWINGS
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIGS. 1 & 2 represent schematically a first embodiment of the invention in ‘OFF’ and ‘ON’ states;
FIGS. 3 & 4 represent schematically a second embodiment of the invention in ‘OFF’ and ‘ON’ states;
FIGS. 5, 6 a & 6 b represent schematically a third embodiment of the invention in ‘OFF’ and ‘ON’ states;
FIGS. 7 & 8 represent schematically a fourth embodiment of the invention in ‘OFF’ and ‘ON’ states;
FIGS. 9, 10 a & 10 b represent schematically a fifth embodiment of the invention in ‘OFF’ and ‘ON’ states; and
FIGS. 11 & 12 a - 12 e represent schematically a sixth embodiment of the invention in ‘OFF’ and ‘ON’ states.
DETAILED DESCRIPTION
In the accompanying drawings, a dual turbo pump assembly is illustrated schematically. Paired turbine and compressor wheels, 11 , 12 and 13 , 14 are mounted for rotation about a common axis, the inner pair 11 , 12 being coupled by a tubular shaft 15 , and the outer pair 13 , 14 being coupled by a shaft (not shown) running within the tubular shaft 15 .
Each pair of wheels is independent of the other, and the outer pair 13 , 14 are annular to permit flow to and from the inner pair, as will become apparent from the following description.
In use flow control valves are provided to direct flow to one or other turbine wheel, and to one or other compressor wheel. The inner pair of wheels 11 , 12 comprise a conventional turbocharger of an internal combustion engine, and the outer pair of wheels comprise a pump for low pressure exhaust gas which is re-circulated to the engine inlet side (an EGR turbo pump).
With reference to FIG. 1 , the dual turbo pump assembly consists of exhaust driven turbines 12 , 14 supplied with exhaust gas from the exhaust manifold 19 of a diesel engine (not shown). After passing through the turbine stages, exhaust gas passes through a diesel oxidation catalyst 16 and a diesel particulate filter 17 to an exhaust tailpipe 18 . In the tailpipe exhaust gas pressure may be characterized as low, compared with exhaust gas pressure upstream of the turbo pump assembly.
In the drawings potential flow paths are indicated by dotted line whereas actual flow paths are indicated by solid line.
FIG. 1 illustrates a configuration where the turbine 14 associated with the EGR turbo pump is not active—an exhaust stream supply valve 21 is closed, and all exhaust gas flow is via the turbine 12 which forms part of the engine turbocharger. Exhaust flow passes through a central aperture in the turbine 14 , but imparts no substantial rotational force thereto, though some free-wheeling may be intentionally permitted to ensure lubrication of the bearings thereof.
In this arrangement, the compressor wheel 11 of the turbocharger operates conventionally to charge the inlet manifold 20 of the engine, and receives inlet air through a central aperture of the compressor wheel 13 , which may freewheel due to the connection to the turbine 14 .
An exhaust gas re-circulation tract 22 directs exhaust gas toward the compressor wheel 13 , but the tract is closed in this embodiment by valve 23 .
Thus in the embodiment of FIG. 1 , the EGR pump is ‘off’.
In FIG. 2 , the EGR pump is ‘on’, and the valve 21 permits flow via the turbine 14 , which in turn drives the compressor wheel 13 . The valve 23 is also open to permit the compressor wheel 13 to draw EGR gas via duct 22 and pump it to the inlet manifold 20 so as to supplement pressurized air from the compressor wheel 11 . Mixing of EGR gas and inlet air preferably occurs upstream of a conventional air to air intercooler (not shown), located upstream of the inlet manifold 20 .
This embodiment permits re-circulation of exhaust gas which is at too low a pressure to flow effectively into the inlet manifold without pumping.
Design and specification of suitable turbine and compressor wheels, valves, flow rates and other variables is within the ability of an appropriately skilled person, and need not be further described here.
In the event that the temperature of re-circulating exhaust gas is too high, a suitable cooler 24 may be incorporated into the EGR duct, for example a gas/water cooler associated with the engine cooling system.
An alternative arrangement is illustrated in FIGS. 3 and 4 . The same components are given identical reference numerals.
This embodiment corresponds to that of FIGS. 1 and 2 save that pressurized exhaust gas passes from the compressor wheel 13 to mix with inlet air upstream of the compressor wheel 11 . FIG. 3 shows the ‘off’ configuration in which valves 21 and 23 are closed. FIG. 4 shows the ‘on’ configuration in which low pressure exhaust gas is pumped to the air inlet duct. The arrangement of FIGS. 3 and 4 may provide better mixing of gases, and an alternative configuration for installing within a congested engine compartment.
In the configuration illustrated in FIGS. 5 and 6 a , the exhaust side is unchanged. FIG. 5 represents an ‘off’ state whereas FIG. 6 a shows an ‘on’ state whereby exhaust gas passes directly to the air inlet tract, and is unboosted. A second valve 25 of the EGR duct closes a flow path to the compressor wheel 13 .
The mixture of EGR gas and air is boosted by the compressor wheel 11 , to supply the inlet manifold 20 .
In the embodiment of FIG. 6 b , the valve 25 is also opened to permit a proportion of exhaust gas to be boosted directly to the inlet tract downstream of the compressor wheel 11 . Flow restrictors, or other means may be provided to determine the flow proportions of the two pathways for the EGR gas stream.
Yet another arrangement is illustrated in FIGS. 7 and 8 . The exhaust side is unchanged. FIG. 7 represents the ‘off’ state, and FIG. 8 the ‘on’ state.
An additional valve 26 is incorporated in the air inlet tract whereby air may be directed to mix with the EGR gas upstream of the compressor wheel 13 . Again, flow restrictors or other means may be provided to determine the proportion of air directed towards valve 23 for mixing with the EGR stream.
Whilst the valve 26 can be open in FIG. 7 , it will be understood that it may also be closed in order to obviate any risk of back flow through the EGR duct 22 . When the valves 26 and 23 are open ( FIG. 8 ), the EGR stream mixes with fresh air in a desired proportion.
FIGS. 9, 10 a and 10 b illustrate another embodiment having valves 23 , 27 corresponding closely to FIGS. 7 and 8 , but a flow path for boosted EGR gas which is directed to the air inlet upstream of the compressor wheels. The exhaust side is unchanged.
Thus in the ‘off’ configuration of FIG. 9 , valves 23 and 27 are closed, and EGR flow is prevented.
In the ‘on’ configuration of FIG. 10 a , valve 23 is opened to permit exhaust gas to be boosted by compressor wheel 13 and admitted to the air inlet tract (this arrangement also corresponds to FIG. 4 ).
In the ‘on’ configuration of FIG. 10 b , the valve 27 is also opened to permit dilution of the exhaust gas entering compressor wheel 13 .
Another embodiment is illustrated in FIGS. 11 and 12 a - 12 e . FIG. 11 represents an ‘off’ configuration, whereas FIGS. 12 a -12 e illustrate various ‘on’ configurations. In these embodiments, a 4-way valve 28 is provided in the EGR duct.
In the first ‘on’ condition ( FIG. 12 a ) exhaust gas is directed to the inlet duct upstream of the compressor wheel 11 (also corresponding to FIG. 6 a ) and is unboosted.
In FIG. 12 b , exhaust gas is boosted via the compressor wheel 13 (also corresponding to FIG. 2 ).
In FIG. 12 c , exhaust gas is both boosted and supplied directly to the inlet tract (also corresponding to FIG. 6 b ).
(In FIG. 12 d , the valve 28 directs inlet air to mix with exhaust gas upstream of the compressor wheel 13 (also corresponding to FIG. 8 ).
In FIG. 12 e , inlet air and exhaust gas are mixed, and proportions supplied to both the inlet tract upstream of compressor wheel 13 and to compressor wheel 11 .
The different flow paths permitted by the configurations described herein can both accommodate installations in engine compartments which are congested, and permit mixing of exhaust gas and fresh air in suitable proportions to achieve a desirable charge to the inlet manifold. In particular it may be possible to achieve desirable temperatures of an inlet charge in addition to a desired proportion of exhaust gas and air.
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An exhaust turbo pump of an internal combustion engine has multiple pairs of turbine and compressor wheels rotatable about a common axis, an inner pair of wheels being connected by a tubular shaft rotatable relative to a spindle connecting an outer pair of wheels. One pair of wheels comprises a turbocharger for inlet air, and another pair of wheels comprises a low pressure EGR pump.
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This application is entitled to and hereby claims the priority of co-pending U.S. Provisional application Ser. No. 61/282,727, filed Mar. 23, 2010.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to the field of animal containment and, more particularly, to a system and method for defining a wireless dog fence that surrounds a user-defined area and for using the fence to contain one or more dogs within the user-defined area.
2. Description of the Related Art
Containing one or more dogs within a prescribed area has been achieved in many different ways, most traditionally through the construction of a fenced enclosure that is high enough to prevent the dog from escaping the enclosure by going over the fence. Since some consider above-ground fencing to be unattractive or otherwise undesirable, “invisible” fence products have been developed that rely on a wire buried underground that defines a desired “fence” border for the dog or dogs. The wire transmits a signal that activates a specially designed collar worn by the dog when the dog comes within a certain proximity of the border. The collar, once activated, can issue an audible warning and/or an electric shock to the dog to ensure that the dog does not leave the “fenced-in” area. Buried wire systems are labor intensive to install. Further, since the wire may be unintentionally cut, or otherwise damaged, such as by digging or tilling during lawn maintenance or the like, such buried wire fence systems are also labor intensive when attempting to find the location of the broken wire or other difficulty.
More recently, wireless fence products have been developed that radiate a low frequency signal to saturate a spherical volume which translates to a generally circular area on the ground plane. The radius of the circle is user-definable and, according to one such product manufactured by PetSafe, generally extends radially from about 5 feet to about 90 feet. When the dog, while wearing a specially designed collar, is “inside” the signal saturated area, the collar receives a signal and no action is taken. When the dog moves outside the signal area, however, the collar delivers a correction signal.
Another wireless system is that marketed by Perimeter Technologies, Inc. which, rather than creating a signal-saturated area, uses a distance measuring technology between the collar and a base unit to determine the range of the dog from the base unit. However, interference created by objects often found within a household environment can cause the collar and base to lose communication with one another, resulting in artificially high range values caused by attenuation or reflection, and/or undesired corrections being delivered to the dog, i.e., corrections when the animal is within the defined containment radius.
Accordingly, a need exists for an improved wireless fencing system that is easy for the consumer to set up and use and that overcomes the problems encountered with prior art systems.
SUMMARY OF THE INVENTION
In view of the foregoing, one object of the present invention is to overcome the difficulties of containing a dog within a wireless fence boundary without administering unwanted corrections to the animal.
Another object of the present invention is to provide a wireless fence system having a dual-antenna base unit and a dual-antenna collar to improve the ratio of successfully received signal transmissions to lost signals.
A further object of the present invention is to provide a wireless fence system in accordance with the preceding objects in which distance values are repeatedly obtained between the base unit and the collar and then weighted and filtered to discount those distance values likely to be errant and to track more accurately the range of the dog from the base unit.
A still further object of the present invention is to provide a wireless fence system in accordance with the preceding objects in which NANOLOC™ chipsets are used in conjunction with a power amplification circuitry to provide greater signal strength for improved reliability in tracking the dog within the fence boundary.
Yet another object of the present invention is to provide a wireless fence system in accordance with the preceding objects in which the tracking process of the system includes a normal battery conservation mode and an accelerated mode during which the distance value sampling rate is increased in response to the dog's proximity to the fence boundary.
It is yet another object of the invention to provide a wireless pet containment product that is user friendly and robust in operation and which effectively tracks the distance between a base unit and the dog to reduce the number of inappropriate corrections administered to the dog.
In accordance with these and other objects, the present invention is directed to a radial-shape wireless fence system for containing one or more dogs in a user-defined area without the need for a physical fence or underground buried wire. As used herein, “radial-shape” refers to a generally circular area defined by a border that encircles a center point defined by the location of the base unit. The border represents an approximate area within which the collar will begin to initiate a correction to the dog. This border area marks the start of a trigger zone which extends outwardly from the border in all directions to a distance at which the collar can no longer receive input from the base unit. This distance, and hence the “size” of the trigger zone, will vary depending upon the terrain and objects between the dog and the base unit, but can be as much as about a mile and a half from the base unit in open flat country. The fence radius, which is set by the user, is the distance between the base unit and the border and defines a roaming area. As long as the dog remains within the roaming area, signal transmissions are effectively sent and received between the base unit and the collar to monitor the dog's range from the base unit in real time, and no corrections are issued to the dog. Under these conditions, the collar may be configured to go to sleep to conserve battery power. In addition, the system may be configured to filter out errant values and/or to take no action if communication is suddenly blocked, such as due to loss of power to the base or collar, or the introduction of a physical signal-blocking element to the system environment.
Also as used herein, the “fence” is an estimated line that runs concentrically with the border of the trigger zone. In the absence of any interference or signal attenuation, the fence would be circular, representing the circumference of a circle defined by the radius. Due to real-world conditions, however, in which signal interference is caused by various objects within the encircled area, or objects anywhere that cause multipath effects, the generally circular roaming area may have segments in which the border or “fence” is closer to the base unit than at other segments, i.e., segments in which the distance between the border/fence and the base unit is less than the fence radius.
The system includes a base unit and at least one collar for a dog, with multiple collars also being supported for additional dogs, which is easy to set up and use. Both the base unit and the collar have two antennas each, providing diversity to improve the ratio of successfully received signal transmissions to lost signals.
The base unit is mounted inside the user's house or other desired indoor location. By following a set-up menu on a display screen and using input elements on the base unit, the user enters a desired fence radius. The user then verifies the desired fence radius by walking outwardly from the base unit with the collar, noting when the collar outputs a signal indicating proximity to the trigger zone and placing a flag or other marker at that location. The user then walks back into the roaming area, moves laterally, and then walks back outwardly until the collar again signals proximity to the trigger zone at which point the user sets another flag or marker. This process is continued until the complete border has been marked with the flags or markers. Using these flags as visual cues of the location of the “fence”, and with the collar on the dog, the user can then train the dog where the fence border is so that the dog can be effectively contained therein.
Once the fence has been set up and the dog trained, the system operates by continuously obtaining distance values between the base unit and the collar in order to track the distance of the dog from the base unit on a real time basis. These distance values are weighted and filtered to discount those distance values likely to be errant due to their disparity with previously measured values and previous calculated estimates of the dog's position. More particularly, through weighting and filtering of a plurality of continuously obtained distance measurement values taken between the base unit and the collar, anomalous measurement values are discounted in terms of their contribution to the current estimate of the dog's location. These filtering techniques in combination with improved signal strength and antenna diversity in the communication between the base unit and the collar improve the accuracy with which the dog's range from the base unit is tracked so that unwanted corrections are not administered to the dog.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the components of a radial-shape wireless fence system in accordance with the present invention.
FIG. 2 illustrates the base unit shown in FIG. 1 as mounted inside a house to define a roaming area and the trigger zone.
FIG. 3 illustrates the fence border and outlying trigger zone of the system set-up shown in FIG. 2 .
FIG. 4 is a flowchart showing the steps taken during the fence setting mode of the system shown in FIG. 1 .
FIG. 5A is an isolated view of the assembled collar shown in FIG. 1 .
FIG. 5B is an exploded view of the components of the collar shown in FIG. 5A .
FIG. 5C is a photograph of the first strap part of the collar strap as shown in FIGS. 5A and 5B , and the antenna to be inserted into the hole in an interior end of the strap part.
FIG. 5D is a photograph of the components shown in FIG. 5C after the antenna has been inserted into the hole in the strap.
FIG. 5E is a photograph of the printed circuit board shown in FIG. 5B , as mounted in the lower housing and with the collar straps connected thereto.
FIG. 5F is a photograph of the collar components shown in FIG. 5B , without the battery, as the upper housing is brought into alignment with the lower housing.
FIG. 5G is a photograph of the collar components shown in FIG. 5F , as the upper housing is brought into engagement with the lower housing to seal the correction unit compartment.
FIG. 5H is a photograph of the collar components shown in FIGS. 5F and 5G with the correction unit compartment positioned for sealing in an ultrasonic welding machine.
FIG. 6 is a flowchart showing the steps taken during the collar setting mode of the system shown in FIG. 1 .
FIG. 7 is a flowchart showing the steps taken during the ranging process of the system shown in FIG. 1 .
FIG. 8 is a flowchart showing the steps taken during the system monitoring mode of the system shown in FIG. 1 .
FIG. 9 is a flowchart showing the steps taken during the tracking process of the system shown in FIG. 1 .
FIG. 10 is a flowchart showing the steps taken during the correction process of the system shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
According to the present invention generally designated by reference numeral 10 , a radial-shape wireless fence system is provided that includes a base controller unit 12 and a remote unit, generally embodied as a collar 14 , as shown in FIG. 1 . For the purposes of training the dog and to provide visual markers for both the dog and the user that generally correspond with the fence border, a set of flags 16 is also preferably provided with the system. The number of flags may be variable, but it is preferred to have from about 25 to about 100 flags, depending upon the radius of the containment or roaming area 32 to be defined.
As shown in FIG. 2 , the base unit 12 is intended to be positioned within the user's home 18 , garage, or other environmentally controlled, indoor area, and is preferably configured to be mounted on a wall. While it is possible to power the base unit with batteries, it is preferably plugged into a properly grounded 120V AC outlet. The base unit has two antennas 20 , 21 for diversity when communicating with the collar 14 , a display screen 24 (preferably LCD) and input elements or buttons, generally designated by reference numeral 26 , for inputting information to set up and control the system. According to a preferred embodiment, the input elements include up and down arrow keys 28 , 29 and an enter button 30 .
The base unit communicates with the collar using an integrated circuit (IC) chip contained within the base unit. According to a preferred embodiment, the chipset is a NANOLOC™ TRX 2.4 GHz transceiver chipset sold by Nanotron Technologies of Berlin, Germany. The NANOLOC™ TRX 2.4 GHz transceiver chipset is an IEEE 802.15.4a chirp spread spectrum radio module with indoor and outdoor ranging capabilities. Other chipsets that use the IEEE 802.15.4a chirping technique for radio frequency distance measurement could also be used.
The base unit 12 is configured to enable the user to set up a custom-sized fence radius of from about 40 to about 400 feet. As noted previously, the radius establishes the distance to the “fence” 31 which encloses the inner roaming area 32 and establishes the border at which the trigger zone 34 begins. While the trigger zone appears to be an annular area or ring 33 as shown in FIG. 3 , the ring 33 actually represents the fact that there is generally some leeway or cushion in the exact location of the border 31 as compared to the fence radius set by the user, due to signal interference and attenuation caused by real-world conditions as already noted. Hence, the point at which a correction is actually initiated could be within or on either the inner or outer edges of the annular area 33 .
As summarized in FIG. 4 , during the fence setting mode, the base unit is located at the center of the desired radial-shaped area to be set up, step 40 . The user enters the desired fence radius into the base unit, step 40 , following a set-up menu displayed on the display screen and using the input elements or buttons 26 to select the desired parameters. Once the radius has been entered, the user walks to the border with the collar to verify that the desired radius has been set by noting where the collar reacts indicating proximity to the trigger zone 34 and places a training flag at that location to define the fence 31 , step 42 . The remainder of the border or fence 31 is flagged off by the user as described in step 44 . A more complete description of the process by which the user enters the fence radius and verifies the location of the fence 31 is set forth in the document entitled “Radial-Shape Wireless Dog Fence Instruction Manual” which is attached hereto as Appendix A and is considered part of the instant disclosure as if fully set forth herein in its entirety.
As shown in FIGS. 5A and 5B , the collar 14 includes a strap generally designated by reference numeral 50 that is fitted around the dog's neck and a correction unit 52 mounted to the strap 50 . The strap 50 includes a first part 49 having holes therein that is coupled to one side of the correction unit 52 , and a second part 51 connected to the other side of the correction unit 52 which has a buckle assembly 53 that can be engaged with the holes to secure the collar 14 around the dog's neck.
The correction unit 52 includes a compartment 29 having a lower housing 66 and an upper housing 54 with a cover 55 through which a CR123A battery 56 , for example, may be inserted into the compartment 29 for providing power to the unit 52 . The correction unit further preferably includes an indicator light 58 , preferably an LED post 59 joined to the upper housing 54 with a waterproof adhesive, that is visible from the outer side of the correction unit and, like the base unit, the collar has two antennas 60 , 61 to provide diversity when communicating with the base unit.
As shown in FIGS. 5C and 5D , the antenna 61 is preferably inserted through an opening 46 and into a blind channel 47 in the collar strap part 49 prior to final assembly of the collar and is secured with silicone or similar material at the strap antenna insertion points. Insertion of antenna 60 into a corresponding hole and channel in strap part 51 is accomplished in like manner.
Housed within the compartment 29 of the collar correction unit 52 is a printed circuit board (PCB) assembly 65 as shown in FIGS. 5 B and 5 E- 5 G. A NANOLOC™ TRX 2.4 GHz transceiver chipset like that in the base controller is integrated with the PCB assembly 65 under RF shield 39 (see FIG. 5E ). The collar and base unit NANOLOC™ chipsets send and receive radio transmissions from one another like 2-way radios. The NANOLOC™ chipsets are preferably enhanced in operation with power amplification circuitry to provide greater signal strength. When radio signals are sent from the antennas of either the base unit or the collar to the other of the two components, these signals propagate in an omni-directional or spherical manner. Using these signals, the enhanced NANOLOC™ chipsets perform a ranging process with their associated antenna pairs which continuously captures, filters and refines the data to yield the distance between the base unit and the collar at any given time, as will be described further hereinafter.
Two probes 64 extend laterally from the lower housing 66 of the compartment 29 that is against the dog's neck and are insulated from the housing 66 by electrode grommets 63 . Shorter probes 67 can be interchangeably mounted to the lower housing 66 to better suit short-haired dogs. Depending upon the setting of the collar, the probes 64 , 67 provide a physical correction signal to the dog upon reaching the trigger zone. Alternatively, the collar can be set to provide only an auditory correction signal to the dog. The physical correction signal is preferably adjustable between a plurality of levels to suit the size, age and temperament of the dog. In a preferred embodiment, the collar defaults to a tone-only correction signal.
To assemble the collar, the ends of the antennas 60 , 61 that extend out of the channels 47 are coupled to connectors on the PCB assembly 65 , preferably with a snap-on or push-on fit. The PCB assembly is received within the lower housing 66 with the collar strap parts 49 , 51 on either side of the lower housing as shown in FIG. 5E . The upper housing 54 is then brought into alignment with the lower housing as shown in FIG. 5F , and then brought closer to engage with the lower housing as shown in FIG. 5G . Once the upper and lower housing are engaged with one another to ultimately close the compartment 29 , the correction unit 52 is sealed, preferably using an ultrasonic welding machine 81 as shown in FIG. 5H . Once fully assembled and welded as shown in FIG. 5A , the collar and correction unit 52 are sufficiently waterproof so as to be able to be submerged for a period of about one minute and thereafter operate at or above 75% of accepted specifications for collar performance.
The collar 14 is set up for use with the fence system of the present invention using the base unit 12 as summarized in FIG. 6 . The consumer can use the base unit to add, delete or change settings for the collar, step 70 . To add another collar for another dog, step 72 , the user presses one of the input buttons 26 on the base unit to place the base unit into a seek mode. When powered on, the collar is programmed to listen for and respond to a signal from an appropriate enabled device such as the base unit. Upon receiving the collar's response signal, the base unit identifies the unique media access control (MAC) address associated with the collar and stores its identity. Collar correction levels and the on/off status of the collar can also be changed using the base unit, step 74 . In addition, collars can be deleted using the base unit, step 76 . A more detailed description of the process by which the user sets up, activates and deletes one or more collars is set forth in Appendix A, previously referenced and attached hereto.
Once the collar has been set up and activated, the NANOLOC™ chipsets perform their ranging function to determine the distance between the base unit and the collar at any given time. The ranging process is as described in connection with the NANOLOC™ chipset on the NANOLOC™ website, and is summarized in FIG. 7 . Ranging occurs on an ongoing basis unless the collar is asleep. The collar sleeps on lack of motion and wakes up when motion is detected by a motion sensor, such as an accelerometer, integrated with the collar.
In brief, the first antenna at the base unit determines a first distance value between itself and the first antenna on the collar, and then determines a second distance value between itself and the second antenna on the collar. The second antenna at the base unit then determines a third distance value between itself and the first antenna on the collar, and then determines a fourth distance value between itself and the second antenna on the collar. If all four distance values are successfully determined, the actual distance value used in terms of obtaining the current estimate of the dog's location is the shortest of the four measured values. This ranging process is more fully described in co-pending application Ser. No. 12/539,404, published as U.S. Publ. No. US 2010/0033339 on Feb. 11, 2010 (“the '339 application”). The '339 application is hereby incorporated by reference and considered part of the instant disclosure as if fully set forth herein in its entirety.
Having two antennas at each of the base unit and the collar improves the ratio of successfully received signal transmissions to lost signals as compared with single antenna systems. This improved ratio is particularly helpful in a household environment in which buildings, shrubs, vehicles and other objects can act to interfere with and/or block signal transmissions. Blocked signals can result in the unwanted issuance of a correction to the dog, i.e., the dog is corrected even though still within the prescribed boundary, or in escapes from the boundary if communication is sufficiently blocked.
The double antenna system also provides for dead zone detection and accommodation. A dead zone is defined as an area in which signal transmission may be lost or compromised. If such dead zones are not detected or otherwise taken into account, this omission can result in an unwanted correction being issued to the dog as the system may conclude from the lack of signal transmission that the dog is outside the boundary. A fuller discussion of the dead zone feature is set forth in the '339 application.
As summarized in FIG. 8 , once set up, the wireless fence system 10 maintains a monitoring mode during which the base unit 12 displays information relating to the status of the battery charge level of the collar 14 , the current distance value between the collar and the base, and whether a breach is detected, step 80 . The base unit 12 may be configured during set-up to sound an alarm when a breach occurs. A breach is defined as having occurred when the distance value between the collar and the base unit is greater than or equal to the radius set up for the fence border, step 82 . When a breach occurs, the system enters a correction mode as will be described further hereinafter.
To reduce the likelihood of an unwanted correction being administered to the dog, the system according to the present invention includes a tracking process which is summarized in FIG. 9 . When performing the tracking process, a valid distance value is stored in flash memory at the base unit, step 90 . However, the base and collar continually transmit and receive signals to calculate updated distance values on an on-going basis to track the dog in real time. During this ongoing process, particular distance values taken at any given time may be slightly inaccurate with respect to the actual location of the dog, indicating the dog to be in the trigger zone when, in fact, the dog is still inside the roaming area. These errant values, if taken on face value, would result in an unwanted correction being administered to the dog. Hence, the tracking process uses an improved Kalman filtering technique with hysteresis to “smooth out” consecutive distance values so that errant values caused by tolerances and attenuation will be ignored, step 92 , and a more accurate tracking distance value obtained, step 100 , as will be described more fully hereinafter.
The tracking process includes a normal battery conservation mode and an accelerated mode for the battery 56 of the collar 14 . Whether the battery conservation mode is appropriate depends upon the difference between the distance value and the fence radius, step 93 . If the difference between the distance value and the fence radius is greater than a threshold value, the tracking mode remains in the normal battery conservation mode in which the current range to the collar is checked every 500 ms, step 95 . If, however, the difference between the distance value and the fence radius is less than the threshold value, indicating the dog to be nearing the fence or border, the system enters a fast range mode in which the range is checked every 100 ms, step 97 . This use of different sampling rates allows for greater battery conservation through less frequent sampling when warranted by the dog's position without sacrificing accurate tracking obtained through accelerated sampling as the dog approaches the fence 31 and trigger zone 34 .
As already described, the tracking process also continually compares the distance value associated with the collar with the fence radius, step 94 , and, if the distance value is less than the fence radius, no action is taken, step 96 . If the distance value is greater than the fence radius, however, a correction sequence is commenced, step 98 .
As summarized in FIG. 10 , the correction process begins when the base unit sends a command to the collar to correct, step 110 . Upon receipt of this command, the collar is activated and issues a correction in the form of a tone and/or physical correction, step 112 . The correction continues until a set time-out period has been reached, step 114 , or until the dog returns approximately 10 feet within the roaming area, step 116 . If the time-out period has been reached, step 114 , the correction stops, step 118 . If the time-out period has not been reached, step 114 , and the dog has returned within the roaming area, step 118 , the correction also stops. If, however, the time-out period has not been reached and the dog has not returned, step 116 , the correction continues, step 112 . The length of the time out period can be varied, but according to one preferred embodiment the time out period is about 30 seconds. The extent to which the dog must return within the roaming area before the correction is stopped could also be more or less than 10 feet according to system design and settings.
To perform the “smoothing out” of consecutive distance values to avoid inadvertent correction of the dog, various types of filtering algorithms may be employed to filter the distance values. In a preferred embodiment, the system according to the present invention uses an enhanced Kalman filtering technique as described in Appendix B, attached hereto and considered part of the instant disclosure as if fully set forth herein in its entirety. Appendix B is an excerpt of a paper entitled, “An Introduction to the Kalman Filter” by Greg Welch and Gary Bishop in the Department of Computer Science at the University of North Carolina at Chapel Hill.
As a means of further smoothing out consecutive distance values and of detecting and ignoring anomalous values, the Kalman filtering algorithm used according to the present invention assigns a weight to each measured distance value according to the apparent reliability or confidence of the measurement sample. The confidence of the measurement sample is determined on the basis of a comparison made between the currently measured distance value and the previously estimated distance value as determined by the Kalman filtering algorithm. If the difference between the currently measured distance value and the previously estimated distance value is greater than a predetermined threshold, then the currently measured distance value is considered to be suspect, i.e., to have limited confidence, and is given little weight. This situation may be illustrated by the following example. The previously estimated distance value between the dog and the base unit was 10 feet and the currently measured distance value, taken a second later, indicates the dog to be 30 feet away from the base unit. The currently measured distance value would appear to be errant since, clearly, the dog could not have covered that much distance in the time that elapsed. A currently measured distance value that represents a realistic movement change, i.e., that shows a position change less than the threshold, is given greater weight when used to calculate an updated estimated distance value from the base unit to the dog. A more detailed description of the weighting process used by the Kalman filtering algorithm according to the present invention is set forth in Appendix B and is also described in the '339 application.
The confidence of the measurement sample may also be evaluated using both a comparison between the currently measured distance value and the previously estimated distance value, and an output of an accelerometer on the collar. If the delta between the currently measured distance value and the previously estimated distance value is large and “high” acceleration is also reported, then the value is given greater weight, i.e., is considered more reliable. If, on the other hand, a large range delta is accompanied by little or no acceleration, then the value is given little weight or ignored as likely representing a bad range value.
It should be noted that the converse of the above identified relationship does not necessarily hold true. For example, a low delta in range values does not become more or less reliable when accompanied by low acceleration reporting due to the incidence of tangential motion under high acceleration. But including the input of the accelerometer may be beneficial when evaluating motion radiating toward or away from the base unit.
The present invention further achieves enhanced robustness in adverse conditions through strength enhancement of the signals being exchanged between the collar and the base unit. This strength enhancement, or signal amplification, allows the base unit and collar to conduct the ranging and tracking processes more accurately than is possible with just the conventionally configured NANOLOC™ chipsets when operating in a household environment where buildings, shrubs, vehicles, etc., can interfere with signal receipt and transmission. According to a preferred embodiment, power amplification circuitry is integrated to work with the NANOLOC™ chipsets to provide greater signal strength.
The present invention may also be adapted to track the location of children, as well as other types of animals, through appropriate modification of the remote unit. For example, rather than a collar, a child could wear a wrist bracelet as the remote unit. The wrist bracelet is configured with a NANOLOC™ chipset like that in the collar already described herein. The wrist bracelet would not have a correction capability, however, but would provide continuous location information to the base unit, including the boundary breach alert signal, for use by the parent or other supervising adult as may be appropriate. Similarly, a harness or collar arrangement could be configured for other animals that, by providing distance information to the base station, would allow the owner to track the animal's location, with or without a correction capability as appropriate.
The foregoing descriptions and drawings should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of ways and is not limited by the dimensions of the preferred embodiment. Numerous applications of the present invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A radial-shaped wireless fence system is provided that contains one or more dogs in a user-defined area without the need for a physical fence or underground wire. The system includes a base unit and at least one collar, and is easy to set up and use. Through improved filtering of consecutive distance measurement values taken between the base unit and the collar, errant measurement values are discounted in terms of their contribution to the current estimate of the dog's distance from the base unit. These filtering techniques, in combination with improved signal strength and antenna diversity in the communication between the base unit and the collar, improve the accuracy and consistency with which the dog's distance from the base unit is tracked so that unwanted corrections are not administered to the dog.
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FIELD OF THE INVENTION
The present invention relates generally to computer systems, and more specifically to control of sequencing of data processing by different programs.
BACKGROUND OF THE INVENTION
The Unix (tm licensed by X/Open Company, LTD) operating system and Linux operating system currently offer a Pipes control program to control sequencing of data processing by different applications. A programmer provides to the Pipes control interpreter program, various program stages (or program functions) and a Pipes command to control sequencing of data between the sages. The Pipes command indicates which stage is entitled to request the output of another, specified stage. For example, a user can provide to the Pipes control program, stages A, B and C and issue the following Pipes command: “Stage A/Stage B/Stage C”. In response, the Pipes control program will form a Pipes application program. According to this Pipes application program, Stage A will generate output data and automatically send it to the Pipes control program. Upon request by Stage B to the Pipes control program, the Pipes control program will furnish to Stage B the output data from Stage A. Stage B will process the output data from Stage A, and automatically send its output data to the Pipes control program. Upon request by Stage C to the Pipes control program for data, the Pipes control program will furnish the output data from Stage B to Stage C. The format for the Pipes command and the interface between each stage and the Pipes control function is based on a predefined protocol. According to the Pipes control function protocol, each stage in the “Pipe” is ignorant of which other stage is the source or recipient of its data, and does not synchronize the data with the prior or subsequent stages. To synchronize the data means to coordinate access to and processing of the data. This simplifies programming of the stages and definition of the Pipes applications by the users. In Unix and Linux Pipes control programs, each stage in the Pipe can receive data from only one stage and can provide data to only one stage, i.e. “single-streaming”. Also, a Unix or Linux Pipes Application is limited to stages and control programs executing in the same real computer.
International Business Machines Corporation has licensed an IBM z/VM operating system to provide a Virtual Machine environment in a real computer. To form a Virtual Machine environment, a base operating system (called “Control Program” or “CP” in IBM Virtual Machine operating systems) logically divides the physical resources (i.e. processor time, memory, etc.) of a real computer into different functional units. Each functional unit or “virtual machine” typically has all the physical resources to execute its own operating system (such as IBM VM/CMS operating systems, Linux (tm of Linus Torvalds) operating system or z/OS operating systems) and applications. Applications, guest operating systems and other programs execute in each virtual machine as if the programs were executing in separate real computers. In these respects, a virtual machine is similar to a logical partition or “LPAR”, which is another known technique to logically divide the physical resources of a computer into different functional units.
The IBM z/VM operating system provides a Pipeline control program in the IBM VM/CMS guest operating system, and IBM z/OS operating system provides a similar Pipeworks control program in its guest operating system. A user provides program stages to each control program and a Pipeline command or Pipeworks command, which is similar to the Pipes command. The known Pipeline control function and Pipeworks control function control sequencing of data between stages, according to the Pipeline or Pipeworks command. The Pipeline or Pipeworks command indicates which stage is entitled to request the output of another, specified stage. For example, a user can provide to the Pipeline control program, Stages A, B and C and issue a Stage A/Stage B/Stage C command. In response, the Pipeline control program will form a Pipeline application program. According to this Pipeline application program, Stage A will generate output data and send it to the Pipeline control program. Upon request by Stage B to the Pipeline control program, the Pipeline control program will furnish to Stage B the output data from stage A. Stage B will process this output data from Stage A, and automatically send its output data to the Pipeline control program. Upon request by Stage C to the Pipeline control program for data, the Pipeline control program will furnish the output data Stage B to Stage C. The format for the Pipeline command and the interface between each stage and the Pipeline control function are based on a predefined protocol. According to the Pipeline control function protocol, each stage in the Pipeline is ignorant of which other stage is the source or recipient of its data, and does not synchronize the data with the prior or subsequent stages. This simplifies programming of the stages and definition of the Pipeline command. A Pipeline or Pipeworks application is limited to stages and control programs executing in the same virtual machine or real computer.
In many respects, the Pipeline and Pipeworks control programs are similar to the Pipes control program. However, as noted above, the Pipes control program only supports “single-streaming”, whereas the Pipeline and Pipeworks control programs support “single-streaming” and “multi-streaming”. In multi-streaming, a Pipeline stage or Pipeworks stage can receive data from one or more other stages and can provide data to one or more other stages. Often times, different units of output from one stage are provided as input to more than one other stage in the “multi-streaming” arrangement so that the other stages can process the output from the one stage in parallel. To implement multi-streaming output, the Pipeline control program provides special purpose stages that can either take multiple streams and convert them into one stream (“fan-in”) or take one stream and convert it into multiple streams (“fan-out”). This allows pipeline applications to be much more flexible than traditional pipes applications, thus enabling pipeline applications to perform a much wider set of tasks. An example of a Pipeline command for a multi-streaming output is as follows:
Pipe (endchar ?) Literal “George Washington” /* define some data */ | a: fanout /*output data to multiple streams */ | > USA Presidents /* write output on first stream to a file */ ? /* end of first stream */ | a: /* start second stream */ | > Bad Golfers/* write output on second stream to a different file */
An example of a Pipeline command for a multi-streaming input is as follows:
Pipe (enchar ?)
Literal “George Washington” /* define data for first stream */
| A: fanin /* input data from multiple streams */
| > USA Presidents_/* output data to a file */
? /* end of first stream */
Literal “John Adams” /* define data for second stream */
A: /* output second stream data to fanin stage */
Parallel processing was also known in non-piping environments. For example, an application has been divided into multiple parts to be run on multiple computers, where communications between the computers are used to synchronize the processing done by such a multi-part program. The purpose of such an arrangement was to provide parallel processing of independent parts of the program where the sequential execution of those parts would not provide sufficient throughput. Such a program is complex because it is difficult to determine exactly which parts of the program are independent and which parts require synchronization. In addition, managing the multiple parts and implementing the required synchronization is also difficult.
It was known in a nonpiping environment to provide shared files in a shared memory accessible by different applications in different virtual machines in the same or different real computer. The nonpiping applications in the different virtual machines can write data to the shared memory without identifying an authorized reader(s) of the data from the shared memory. The nonpiping applications in the different virtual machines can read data from the shared memory without identifying an authorized writer(s) of the data to the shared memory. It was known that these nonpiping applications could process in parallel the data read from the queue, and return resultant data to the queue. It was also known in a nonpiping environment to serialize access to the data in the shared memory by providing a shared queue in the shared memory. It was also known in a nonpiping environment to synchronize access to the data in the shared memory by a shared lock structure.
An object of the present invention is to improve the versatility of a Pipes control program, Pipeline control program, Pipeworks control program and other such piping control programs.
SUMMARY OF THE INVENTION
The present invention resides in a computer system, method and program product for processing data by first, second and third piping applications. A first piping application is defined by combining first and second stages of programming with a first sequence control program and specifying to the first sequence control program a first piping command. The second stage is a function to send data to a shared queue. The first piping command identifies the first stage, the second stage and parameters for the second stage identifying the queue and a key for the data to be sent to the queue. A second piping application is defined by combining third and fourth stages of programming with a second sequence control program, and specifying to the second sequence control program a second piping command. The third stage is a function to read the data from the queue. The second piping command identifies the fourth stage, the third stage, and parameters for the third stage identifying the queue and the key for the data to be read from the queue. A third piping application is defined by combining fifth and sixth stages of programming with the second sequence control program, and specifying to the second sequence control program a third piping command. The fifth stage is a function to read the data from the queue. The third piping command identifies the sixth stage, the fifth stage and parameters for the fifth stage identifying the queue and the key for the data to be read from the queue. The first, second and third piping applications are executed based on their respective definitions, stages and sequence control programs. The first piping command does not identify the second or third piping applications. The second piping command does not identify the first or third piping applications. The third piping command does not identify the first or second piping applications.
According to features of the invention, the first stage receives and processes data from the first sequence control program and sends resultant, first stage output data to the first sequence control program. The second stage receives the first stage output data from the first sequence control program and sends the first stage output data to the queue with the key. The third stage receives and processes from the queue some of the first stage output data sent by the second stage to the queue and sends resultant, third stage output data to the second sequence control program. The fourth stage receives and processes the third stage output data from the second sequence control program and sends resultant, fourth stage output data to the second sequence control program. The fifth stage receives and processes from the queue other of the first stage output data sent by the second stage to the queue and sends resultant, fifth stage output data to the second sequence control program. The sixth stage receives and processes the fifth stage output data from the second sequence control program and sends resultant, sixth stage output data to the second control program.
According to other features of the present invention, the first piping application does not identify the second piping application or the third piping application. The second piping application does not identify the first piping application or the third piping application. The third piping application does not identify the first piping application or the second piping application.
According to other features of the present invention, the first piping application executes in a first real computer, and the second and third piping applications execute in a second real computer.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a block diagram of a distributed computer system which includes one Piping Application based on one sequence control program and one set of stages in one computer and another Piping application based on another sequence control program and another set of stages in another computer, according to the present invention.
FIG. 2(A) is a flow chart illustrating in more detail the one Piping application in the one computer of FIG. 1 .
FIG. 2(B) is a flow chart illustrating in more detail the other Piping application in the other computer of FIG. 1 .
FIG. 3 is a block diagram of a distributed computer system which includes one Piping Application based on one sequence control program and stages in one computer and two other Piping Applications, which execute in a parallel, load balancing arrangement, based on another sequence control program and other stages in another computer, according to the present invention.
FIG. 4 is a flow chart illustrating in more detail one of the other Piping applications in the other computer of FIG. 3 .
FIG. 5 is a flow chart illustrating in more detail the other of the other Piping applications in the other computer of FIG. 3 .
FIG. 6 illustrates another embodiment of the present invention where a single real computer with a processor, RAM, ROM on a bus and storage is divided into virtual machines by a base operating system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail with reference to the figures. FIG. 1 illustrates a distributed computer system generally designated 10 according to the present invention. System 10 comprises a real computer 12 with a known processor 13 , operating system 14 , RAM 15 and ROM 16 on a common bus 17 , and storage 18 . System 10 also comprises another real computer 22 with a known processor 23 , operating system 24 , RAM 25 and ROM 26 on a common bus 27 , and storage 28 . Operating system 14 can be any of a variety of known operating systems such as Unix, Linux, Microsoft Windows, IBM z/VM, or IBM z/OS operating system. Likewise, operating system 24 can be any of a variety of known operating systems such as Unix, Linux, Microsoft Windows, IBM z/VM system, or IBM z/OS operating system, and can be the same or different than operating system 12 . System 10 also includes a shared queue 30 and shared queue manager 32 . Shared queue 30 can be in a shared or non shared memory of computer 12 , computer 22 , in another computer (not shown) or in disk storage.
Computer 12 also includes a sequence control program 60 and program stages A 1 , A 2 , A 3 , A 4 . . . An which form a Piping Application A based on a piping command PC-A 61 , according to the present invention. The piping command PC-A 61 specifies each stage in Piping Application A and the sequence of the stages. The sequence of the stages indicates the flow of data from one stage to the next. In the illustrated example, Stage A 2 is a “disperse” stage, which is a program function which receives data or records from sequence control program or interpreter 60 and sends it to queue 30 . In the case of the “disperse” stage, the piping command also includes the identity of the queue to receive the data or records to be dispersed and a key to identify this data and distinguish it from other data on the same queue. In the illustrated example, Stage A 3 is a “collect” stage, which is a program function which receives data or records from queue 30 and sends it to sequence control program 60 . In the case of the “collect” stage, the piping command indicates the identity of the queue from which to fetch the data and a key to identify this data and distinguish it from other data on the sane queue. The control program 60 implements the piping command by invoking each stage in the specified sequence, receiving the output data from each stage and furnishing the output data from each stage to the next stage in the sequence. In the illustrated example, stage A 1 provides some function which generates a data or record output and supplies it to control program 60 . Stage A 1 does not indicate or know the next stage in the sequence. As noted above, Stage A 2 is a function which receives the output data from Stage A 1 via control program 60 and disperse this output data from stage A 1 to a shared queue 30 (without modification). However, Stage A 2 does not indicate or know of Stage A 1 ; rather, Stage A 2 merely requests data, and control program 60 is programmed to provide the output data from Stage A 1 . Stage A 3 provides a function to collect other data from shared queue 30 and furnish the collected data to stage A 4 via control program 60 . However, Stage A 3 does not indicate or know the original source of the data to be collected from queue 30 , except that is will reside in the queue 30 . Also, Stage A 3 does not indicate or know that Stage A 4 will receive this data from control program 60 ; rather, Stage A 3 automatically sends the data to control program 60 . Stage A 4 does not indicate or know Stage A 3 ; rather, Stage A 4 merely requests data from control program 60 , and control program 60 is programmed to provide the data output from Stage A 3 to Stage A 4 upon request by Stage A 4 . Stage A 4 provides some function which generates a data or record output based on the data from stage A 3 and furnish the result to control program 60 . Piping Application A can include other, subsequent stages. All stages in Application A read their input from and send their output to control program 70 , except the disperse stage which outputs its data to the queue 30 and the collect function which reads its data from the queue 30 . The overall function of Application A is not important to the present invention, and could be a system management function, resource management function or communication application as examples.
Computer 22 also includes a sequence control program or interpreter 70 (which is similar to sequence control program or interpreter 60 ) and program stages B 1 , B 2 , B 3 . . . Bn which form a resultant Piping Application B based on a piping command PC-B 71 , according to the present invention. The piping command PC-B 71 specifies each stage in Piping Application B and the sequence of the stages. The sequence of the stages indicates the flow of data from one stage to the next. In the illustrated example, Stage B 1 is a “collect” stage, which is a program function which receives data or records from queue 30 and sends it to sequence control program 70 . In the case of the “collect” stage, the piping command indicates the identity of the queue from which to fetch the data and a key to identify this data and distinguish it from other data on the sane queue. In the illustrated example, Stage B 3 is a “disperse” stage, which is a program function which receives data or records from sequence control program 70 and sends it to queue 30 . In the case of the “disperse” stage, the piping command also includes the identity of the queue to receive data to be dispersed and a key to identify this data and distinguish it from other data on the same queue. The control program 70 implements the piping command by invoking each stage in the specified sequence, receiving the output data from each stage and furnishing the output data from each stage to the next stage in the sequence. In the illustrated example, Stage B 1 collects from the shared queue 30 the data sent by disperse Stage A 2 of Piping Application A and furnishes this data to Stage B 2 via control program 70 . However, Stage B 1 does not indicate or know the original source of the data to be collected, except that is will reside in the queue 30 (and the key for the data to be collected). Also, Stage B 1 does not indicate or know that Stage B 2 will receive the data from control program 60 ; rather, Stage B 1 automatically sends the data it collects to control program 70 . Stage B 2 provides some function which generates a data or record output to control program 70 based on the data collected by Stage B 1 from the queue. Stage B 2 does not know or indicate that Stage B 3 will read and process this data from the control program 70 . Stage B 3 receives the data or record output from stage B 2 via control program 70 and disperses the data or record output from stage B 2 to shared queue 30 where it is available to collect Stage A 3 of Piping Application A. Stage B 3 does not know or indicate the stage that generated the data that it receives from control program 70 and disperses to the queue, and does not know the stage that will fetch and process the data that it sends to queue 30 . Stage B 3 does not know or indicate that Piping Application A will fetch and process the data that Stage B 3 writes to queue 30 . Piping Application B can include other stages such as the foregoing. All stages in Application B read their input from and send their output to control program 70 , except the disperse stage B 3 outputs its data to the queue 30 and the collect Stage B 1 reads its data from the queue 30 . The overall function of Application B is not important to the present invention, and could be a system management function, resource management function or communication application as examples.
FIG. 2(A) is a flowchart illustrating processing by Piping Application A including sequence control program 60 and stages A 1 -A 4 for the example illustrated in FIG. 1 . In this example, the developer of Application A previously supplied and combined Stages A 1 -A 4 with the sequence control program 60 and previously issued the following command to sequence control program 60 to form Application A:
Stage A 1 |Disperse(Queue 30 , Key X)|Collect(Queue 30 , Key Y, T1)|Stage A 4
In step 200 , Application A is invoked, and in response, sequence control program 60 calls the first stage, Stage A 1 62 , in Application A (step 201 ). Control program 60 calls Stage A 1 with the following command (which identifies Stage A 1 ):
“Stage A 1 ” (with parameters when needed)
If control program 60 has data for Stage A 1 , then control program 60 supplies such data to Stage A 1 in step 201 . After Stage A 1 executes (and processes data, if any, supplied by control program 60 ), Stage A 1 generates a data or record output which Stage A automatically supplies to control program 60 (step 202 ). Next, sequence control program 60 calls its second stage, Stage A 2 63 , in Application A (step 204 ). In the illustrated example, Stage A 2 is a disperse stage, and control program 60 calls the disperse stage with the following command:
“Disperse(Queue 30 , Key X)”
Sequence control program 60 also correlates this first stage output data with Key X (step 205 ). In response to the disperse command, the disperse stage A 2 reads first output stage data identified by Key X from sequence control program 60 (step 206 ), tallies the total number of records received from control program 60 (step 208 ), and then “disperses” or writes the first stage output data or records onto the shared queue 30 along with Key X (step 210 ). Disperse stage 63 also supplies to the control program 60 the total number of records received from control program 60 and written to queue 30 (step 212 ). Another program stage can use this tally of records to ensure that it has collected responses for all the records. After completion of disperse stage A 2 63 , control program 60 calls the next stage A 3 64 , which in the illustrated example is a collect stage (step 220 ). Control program 60 calls the collect stage A 3 with the following command:
“Collect(Queue 30 , Key Y, T1)”
This collect command directs collect stage A 3 64 to read from queue 30 data identified by Key Y until all records have been read or a time-out of “T1” seconds is reached. In response, collect stage A 2 64 attempts to read such data from queue 30 (step 224 ). If such data is currently resident on queue 30 , collect stage A 2 64 will send it to control program 60 (step 226 ). Next, control program 60 continues by invoking the next stage in Application A, which in the illustrated example is stage A 4 , with the following command (step 230 ):
“Stage A 4 ” (with parameters when needed)
With this call, control program 60 will supply the data with Key Y fetched by collect Stage A 3 from queue 30 . In response, stage A 4 will process this data (step 240 ), and return the results to control program 60 (unless stage A 4 is a disperse stage). If there are any other stages in Application A, then control program 60 invokes them in sequence.
FIG. 2(B) illustrates processing by Piping Application B, including sequence control program 70 and Stages B 1 -B 3 based on piping command 71 . Piping Application B exchanges data with Piping Application A as described in FIG. 2(A) , even though each application is unaware of the other application. The developer of Application B previously provided and combined Stages B 1 -B 3 with sequence control program 70 and previously issued the following piping command to sequence control program 70 to form Application B:
“Collect(Queue 30 , Key X, T2 Seconds)|Stage B 2 |Disperse(Queue 30 , Key X)”
In step 300 , Application B is invoked and in response, control program 70 calls its first stage, Stage B 1 (step 301 ). In the illustrated example, Stage B 1 is collect Stage 74 , and is called with the following command:
“Collect(Queue 30 , Key X, T2)”
In response, collect Stage 74 attempts to read data with Key X from queue 30 until all records have been read or a time-out T 2 is reached (step 302 ). The data with Key X was previously supplied or will be supplied by Application A in step 2 _. Assuming there is data in queue 30 identified by Key X via disperse stage A 1 62 , the collect Stage B 1 74 fetches the data identified by Key X from queue 30 up until the number of first stage records supplied by disperse stage 63 of Application A (or until time-out T 2 is reached) (step 302 ) Then, collect Stage B 1 74 supplies the first stage records to sequence control program 70 (step 308 ). Next, control program 70 continues its processing of Application B by invoking the next stage B 2 of Application B (step 310 ) with the following call:
“Stage B 2 ” (with parameters when needed)
When invoking Stage B 2 , control program 70 also supplies to Stage B 2 the data with Key X from queue 30 supplied by disperse Stage A 2 63 and fetched by collect Stage B 1 74 . Stage B 2 processes the data with Key X from queue 30 (step 314 ), and sends its results to control program 70 (step 316 ).
Control program 70 continues its processing of Application B by invoking the next stage, Stage B 3 of Application B (step 320 ). In the illustrated example, Stage B 3 , is disperse Stage 73 , and control program 70 invokes disperse Stage 73 with the following command:
“Disperse (Queue 30 , Key Y)”
Control program 70 also correlates the data output from Stage B 2 with Key Y (step 320 ). In response to invocation of disperse Stage B 3 , disperse Stage B 3 reads from control program 70 the data with Key Y (step 324 ) and also tallies the number of data records with Key Y read from control program 70 (step 326 ). Next, disperse Stage B 3 writes the records with Key Y onto queue 30 and also supplies the tally from step 326 to the control program 70 (step 330 ). These records with Key Y then become available to Application A via collect Stage A 3 64 , as noted above. If there are any other stages in Application B, then control program 70 invokes them in sequence.
Thus, the developers of Applications A and B can easily define Application A and Application B using a piping construct, and allow Applications A and Application B to exchange data in one or both directions without the developer having to synchronize the movement of data within either Application A or Application B or the exchange of data between Application A and Application B. Also, the data can be exchanged across different real computers (as illustrated) without the developer of Application A or Application B having to synchronize the transfer of the data across real computers. (If desired, both Applications A and B, and queue 30 could reside in the same real computer, such as computer 12 .)
In addition, Application A is “distinct” from the Application B in that the piping command that defined the sequence of stages in Application A, and Application A itself, did not mention Application B, and the piping command that defined the sequence of stages in Application B, and Application B itself, did not mention Application A. Application A does not control what other Application or Applications read and process the data with Key X sent by Application A to queue 30 , and Application A does not control what other Application or Applications furnish the data with Key Y to queue 30 that Application A subsequently receives and processes. Likewise, Application B does not control what other Application or Applications read and process the data with Key Y sent by Application B to queue 30 , and Application B does not control what other Application or Applications furnish the data with Key X to queue 30 that Application B subsequently receives and processes.
FIG. 3 illustrates another example of usage of sequence control program or interpreter 60 and Stages A 1 -A 4 , An . . . and piping command 61 to form Piping Application A. Application A in FIG. 3 is the same as Application A in FIG. 1 described above. FIG. 3 also illustrates another example of usage of sequence control program 70 and Stages B′ 1 - 3 , Bn and C 1 - 3 , Cn to form Piping Application B′ and Piping Application C′, respectively. Applications B′ and C′ process in parallel (the same as processing by Application B alone in FIG. 1 ) the data with Key X supplied by Application A to queue 30 . Applications B′ and C′ supply resultant data with Key Y to queue 30 (the same as returned by Application B alone in FIG. 1 ). Application B′ is the same as Application B except as follows, and Application C′ is the same as Application B′. In the example of FIG. 3 , Applications B′ and C′ are programmed, based on a parameter in control program 70 , to read different units of the data with Key X from queue 30 during execution of their respective collect Stages B′ 1 and C′ 1 , as follows. Each of the collect Stages B 1 ′ and C 1 ′ is programmed to read only a finite number of records during each iteration of Stages B 1 ′ and C 1 ′ as specified in control program 70 so that the data with Key X supplied by Application A is split, processed and load balanced between Applications B′ and C′. (In other words, data records read by collect stage B′ 1 are not available to be read by collect stage C′ 1 , and vice versa, so the same data records with Key X are not read or processed by both Applications B′ and C′.) Thus, Applications B and C process in parallel the data with Key X supplied by Application A to queue 30 , and furnish to queue 30 the resultant data with Key Y. The data output from both Applications B′ and C′ is sent to queue 30 under the same Key Y and is combined in queue 30 and available to Application A. Thus, Application A collects the data with Key Y from both Applications B′ and C′. The developer of Application B′ previously provided and combined Stages B′ 1 -B′ 3 with sequence control program 70 , and previously defined Application B′ with the following command to sequence control program 70 :
“Collect(Queue 30 , Key X, T2)|Stage B′ 2 |Disperse(Queue 30 , Key X)”
The developer of Application C′ previously provided and combined Stages C′ 1 -C′ 3 with sequence control program 70 , and previously defined Application C′ with the following command to sequence control program 70 :
“Collect(Queue 30 , Key X, T2)|Stage C′ 2 |Disperse(Queue 30 , Key X)”
In the illustrated example, both Applications B′ and C′ utilize the same instance of sequence control program 70 , and sequence control program 70 is an interpreter. (However, if desired, there could be separate instances of sequence control program 70 for Applications B′ and C′.)
Application A is “distinct” from the Applications B′ and C′ in that the command that defined the sequence of stages of Application A, and Application A itself, did not mention Applications B′ or C′ and the commands that defined the sequence of stages of Applications B′ and C′ did not mention Application A. Application A does not control what other Application or Applications read and process the data with Key X sent by Application A to queue 30 , and Application A does not control what other Application or Applications furnish the data with Key Y to queue 30 that Application A subsequently receives and processes. Likewise, Applications B′ and C′ do not control what other Application or Applications read and process the data with Key Y sent by Applications B′ and C′ to queue 30 , and Applications B′ and C′ do not control what other Application or Applications furnish the data with Key X to queue 30 that Applications B′ and C′ subsequently receive and process in parallel.
FIG. 4 illustrates Application B′ in more detail, and FIG. 5 illustrates Application C′ in more detail. The steps of Application C′ indicated by a “″” at the end of the reference number in FIG. 5 are the same as the corresponding steps of Application B indicated by a “′” at the end of the reference number in FIG. 4 . The steps of Application B′ indicated by a “′” at the end of the reference number in FIG. 3(B) are the same as the corresponding steps of Application B which omit the “′” at the end of the reference number in FIG. 4 , except as follows. In step 302 ′ of FIG. 4 , Application B′ only reads N Key X records from queue 30 in each iteration of step 302 ′, not all the Key X records available from queue 30 . Likewise, in step 302 ″ of FIG. 5 , Application C′ only reads N Key X records from queue 30 in each iteration of step 302 ″, not all the Key X records available from queue 30 . This allows both Applications B′ and C′ to process different Key X data in queue 30 in parallel, in a load balancing arrangement. In subsequent step 308 ′ and 308 ″ of FIGS. 4 and 5 , only the N Key X records are sent to the control program 70 , and in subsequent steps 310 ′ and 310 ″ of FIGS. 4 and 5 only the N Key X records are processed by the next stage B′ 2 and C′ 2 during each iteration of Applications A and B.
FIG. 6 illustrates another embodiment of the present invention where a single real computer 412 with a processor 413 , RAM 414 , ROM 415 on a bus 419 and storage 418 are divided into virtual machines 420 and 430 by a base operating system 414 . Piping Application A executes in virtual machine 420 , and Piping Applications B′ and C′ execute in virtual machine 430 . Piping Applications A, B′ and C′ are the same as described above with reference to FIGS. 1 , 2 (A), 3 , 4 and 5 .
Sequence control program 60 can be loaded into computer 12 from a computer readable media 111 , such as magnetic tape or disk, optical media, DVD, memory stick, semiconductor memory, etc. or downloaded from the Internet 87 via TCP/IP adapter card 88 .
Program stages A 1 -A 4 . . . An can be loaded into computer 12 from a computer readable media 111 , such as magnetic tape or disk, optical media, DVD, memory stick, semiconductor memory, etc. or downloaded from the Internet 87 via TCP/IP adapter card 88 .
Sequence control program 70 can be loaded into computer 22 from a computer readable media 121 , such as magnetic tape or disk, optical media, DVD, memory stick, semiconductor memory, etc. or downloaded from the Internet 87 via TCP/IP adapter card 89 .
Program stages B 1 -B 3 . . . Bn, B′ 1 -B′ 3 . . . B′n and C′ 1 -C′ 3 . . . C′n can be loaded into computer 12 from a computer readable media 121 , such as magnetic tape or disk, optical media, DVD, memory stick, semiconductor memory, etc. or downloaded from the Internet 87 via TCP/IP adapter card 88 .
Based on the foregoing, a system, method and program product for sequencing processing of data by different programs have been disclosed. However, numerous modifications and substitutions can be made without deviating from the scope of the present invention. Therefore, the present invention has been disclosed by way of illustration and not limitation, and reference should be made to the following claims to determine the scope of the present invention.
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Generally, piping applications defined by combining stages of programming with a sequence control program and specifying to the sequence control program piping commands. The stages may be functions to send data to a shared queue. The piping commands identify current stages, and parameters for the current stages identify the queue and a key for the data to be sent to the queue. The piping commands do not identify preceding and/or subsequent piping applications.
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BACKGROUND
1. Field of Invention
The invention relates generally to current generators, and more particularly, to spin current generators for spintronics applications.
2. Description of Related Art
This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light and not as admissions of prior art.
The development of microelectronics has led to large increases in integration density and efficiency. However, the conventional electronic methods of operation by applying voltage to control electron charge are fundamentally limited. Further improvements in nonvolatility, speed, and size of electronic devices may require advancements in new technology. Spintronics, or spin electronics (also known as spin transport electronics and magnetoelectronics), refers to the study of the spin of an electron in solid state physics and the possible devices that may advantageously use electron spin properties instead of, or in addition to, the conventional use of electron charge.
The spin of an electron has two states and is characterized as being either “spin up” or “spin down.” Conventional spintronics devices have relied on systems that provide bidirectional current to alter the electron spins in the device. For example, one spintronics application involves data storage through a spintronics effect known as giant magnetoresistance (GMR). The GMR structure includes alternating ferromagnetic and nonmagnetic metal layers, and the magnetizations and electron spins in each of these magnetic layers provide resistance changes through the layers. The resistance of the GMR may change from low (if the magnetizations are parallel) to high (if the magnetizations are antiparallel), and the inducing and detecting of such magnetoresistance changes are the basis for writing and reading data. Another example of spintronics devices includes spin torque transfer magnetic random access memory (STT-MRAM). STT-MRAM also exploits electron spin polarity by utilizing the electron spin to switch the magnetization of ferromagnetic layers to provide two programmable states of low and high resistance.
This alteration of magnetization typically employs a bidirectional programming current to change the magnetizations of the layers in a memory cell. However, bidirectional programming logic requires more cell space. A transistor select device is required for each memory cell, and this also increases the cell area. Furthermore, bidirectional programming logic is generally more complicated and less efficient than unidirectional programming logic.
BRIEF DESCRIPTION OF DRAWINGS
Certain embodiments are described in the following detailed description and in reference to the drawings in which:
FIG. 1 depicts a block diagram of a processor-based system in accordance with an embodiment of the present technique;
FIG. 2 depicts a device architecture and method by which a spin current generator may enable a spintronics device in accordance with embodiments of the present technique;
FIG. 3 depicts a spin current generator capable of generating non-polarized or adjustably polarized current in accordance with embodiments of the present invention; and
FIG. 4 depicts a spin current generator capable of generating adjustably polarized current in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
Spintronics devices write and store information by manipulating electron spin in a particular orientation. As previously discussed, information may be stored by programming magnetic layers in a memory cell into low resistance and high resistance states. Switching between the two resistance states typically employs a bidirectional programming current, where a current passed in one direction may orient the magnetization of memory cell layers to a low resistance state, and a current passed in an opposite direction may orient the magnetization of memory cell layers to a high resistance state. Since bidirectional programming logic requires more complicated circuitry and more chip space, a method of generating electron currents with desired spin polarizations may reduce the complexity and size of memory cell area or other devices requiring currents of different polarities by facilitating unidirectional programming. The following discussion describes the systems and devices, and the operation of such systems and devices in accordance with the embodiments of the present technique.
FIG. 1 depicts a processor-based system, generally designated by reference numeral 10 . As is explained below, the system 10 may include various electronic devices manufactured in accordance with embodiments of the present technique. The system 10 may be any of a variety of types such as a computer, pager, cellular phone, personal organizer, control circuit, etc. In a typical processor-based system, one or more processors 12 , such as a microprocessor, control the processing of system functions and requests in the system 10 . As is explained below, the processor 12 and other subcomponents of the system 10 may include resistive memory devices manufactured in accordance with embodiments of the present technique.
The system 10 typically includes a power supply 14 . For instance, if the system 10 is a portable system, the power supply 14 may advantageously include a fuel cell, a power scavenging device, permanent batteries, replaceable batteries, and/or rechargeable batteries. The power supply 14 may also include an AC adapter, so the system 10 may be plugged into a wall outlet, for instance. The power supply 14 may also include a DC adapter such that the system 10 may be plugged into a vehicle cigarette lighter, for instance.
Various other devices may be coupled to the processor 12 depending on the functions that the system 10 performs. For instance, a user interface 16 may be coupled to the processor 12 . The user interface 16 may include buttons, switches, a keyboard, a light pen, a mouse, a digitizer and stylus, and/or a voice recognition system, for instance. A display 18 may also be coupled to the processor 12 . The display 18 may include an LCD, an SED display, a CRT display, a DLP display, a plasma display, an OLED display, LEDs, and/or an audio display, for example. Furthermore, an RF sub-system/baseband processor 20 may also be coupled to the processor 12 . The RF sub-system/baseband processor 20 may include an antenna that is coupled to an RF receiver and to an RF transmitter (not shown). One or more communication ports 22 may also be coupled to the processor 12 . The communication port 22 may be adapted to be coupled to one or more peripheral devices 24 such as a modem, a printer, a computer, or to a network, such as a local area network, remote area network, intranet, or the Internet, for instance.
The processor 12 generally controls the system 10 by implementing software programs stored in the memory. The software programs may include an operating system, database software, drafting software, word processing software, and/or video, photo, or sound editing software, for example. The memory is operably coupled to the processor 12 to store and facilitate execution of various programs. For instance, the processor 12 may be coupled to the system memory 26 , which may include spin torque transfer magnetic random access memory (STT-MRAM), magnetic random access memory (MRAM), dynamic random access memory (DRAM), and/or static random access memory (SRAM). The system memory 26 may include volatile memory, non-volatile memory, or a combination thereof. The system memory 26 is typically large so that it can store dynamically loaded applications and data. In some embodiments, the system memory 26 may include STT-MRAM devices, such as those discussed further below.
The processor 12 may also be coupled to non-volatile memory 28 , which is not to suggest that system memory 26 is necessarily volatile. The non-volatile memory 28 may include STT-MRAM, MRAM, read-only memory (ROM), such as an EPROM, resistive read-only memory (RROM), and/or flash memory to be used in conjunction with the system memory 26 . The size of the ROM is typically selected to be just large enough to store any necessary operating system, application programs, and fixed data. Additionally, the non-volatile memory 28 may include a high capacity memory such as a tape or disk drive memory, such as a hybrid-drive including resistive memory or other types of non-volatile solid-state memory, for instance. As is explained in greater detail below, the non-volatile memory 28 may include STT-MRAM devices manufactured in accordance with embodiments of the present technique.
Both the system memory 26 and the non-volatile memory 28 may include memory cells programmable by manipulation of electron spin or other spintronics components. For example, the memory cells may include MRAM cells, STT-MRAM cells, or memory cells that utilize the giant magnetoresistive (GMR) effect. The system memory 26 and the non-volatile memory 28 may further include a spin current generator to generate single-spin polarity current (i.e., a current that can be generated with a spin polarity in only one direction), bi-spin polarity current (i.e., a current that can be generated with a spin polarity in either direction), non-polarized current or arbitrary spin-polarized current to program the memory cells, as will be further described below.
FIG. 2 depicts an example of a portion of a spintronics device and a method by which a spin current generator 100 may be used to program the device in accordance with embodiments of the present technique. The portion of the spintronics device illustrated here includes an array 102 of memory cell components 104 with magnetic layers 106 and 108 . As will be appreciated, each memory cell component 104 may form the memory portion of a single memory cell in the array 102 . The memory cell components 104 may include magnetic tunnel junctions (MTJs), stacks of ferromagnetic and nonmagnetic layers, or any other structure in which magnetization may be manipulated to alter the structure's magnetoresistance state. Furthermore, the memory cell components 104 may be components of magnetic random access memory (MRAM) cells, spin torque transfer magnetic random access memory (STT-MRAM) cells, or any other device exploiting the manipulation of electron spin to program the cell.
In this example, the memory cell component 104 includes a pinned layer 106 and a free layer 108 . A memory cell may be “written” or “programmed” by switching the magnetization of the free layer 108 in the memory cell component 104 , and the cell may be read by determining the resistance across the free layer 108 and the pinned layer 106 . The layers 108 and 106 may comprise ferromagnetic materials, such as Co, Fe, Ni or its alloys, NiFe, CoFe, CoNiFe, or doped alloys CoX, CoFeX, CoNiFeX (X=B, Cu, Re, Ru, Rh, Hf, Pd, Pt, C), or other half-metallic ferromagnetic material such as Fe3O4, CrO2, NiMnSb and PtMnSb, and BiFeO, for instance. The pinned layer 106 is so named because it has a magnetization with a fixed or pinned preferred orientation, and this is represented by the unidirectional arrow illustrated in the pinned layer 106 . An additional layer of antiferromagnetic material may be deposited below the pinned ferromagnetic layer to achieve the pinning through exchange coupling. The bidirectional arrow illustrated in the free layer 108 represents that the free layer 108 may be magnetized either in a direction parallel to the pinned layer 106 , which gives a low resistance, or in a direction antiparallel to the pinned layer 106 , which gives a high resistance. The memory cell component 104 may also include a nonmagnetic layer between the free layer 108 and the pinned layer 106 to serve as an insulator between the two layers 108 and 106 , thereby forming a MTJ structure in this example. The nonmagnetic layer may include materials such as AlxOy, MgO, AlN, SiN, CaOx, NiOx, HfO2, Ta2O5, ZrO2, NiMnOx, MgF2, SiC, SiO2, SiOxNy, for example.
The spin current generator 100 is connected to each memory cell in the array 102 through source lines 110 . In the presently illustrated embodiment, each of the memory cell components 104 is coupled in series to form a string, such that each of the memory cell components 104 is coupled to a common source line 110 . When a memory cell is selected to be programmed, the spin current generator 100 sends a spin polarized current through the source line 110 to the selected memory cell and memory cell component 104 . If the memory cell is to be programmed to a low resistance state (“write 1 operation”) 114 , the spin current generator 100 will generate a current polarized in one direction (e.g., to the left) 116 , and the left-polarized current will switch the magnetization of the free layer 108 to the left. Because the magnetization of the pinned layer 106 is also directed to the left, the magnetizations of the free layer 108 and the pinned layer 106 are parallel, and the memory cell is programmed to a low resistance state. Likewise, if the memory cell is to be programmed to a high resistance state (“write 0 operation”) 118 , the spin current generator 100 will generate a current polarized in an opposite direction (to the right) 120 , and the right-polarized current will switch the magnetization of the free layer 108 to the right. Because the magnetization of the pinned layer 106 is directed to the left, the magnetizations of the free layer 108 and the pinned layer 106 are antiparallel, and the memory cell is programmed to a high resistance state.
The method depicted in accordance with embodiments of the present technique thus enables the memory cells or other spintronics devices to be programmed by a unidirectional current, allowing for simpler unidirectional programming logic. As previously discussed, conventional spintronics devices, including STT-MRAM devices, typically use bidirectional programming logic, meaning the write current is driven in opposite directions through a device cell stack to switch the cell between different programmable states. For example, in a STT-MRAM cell, a write current may be driven from a transistor source to a transistor drain, and then through a MTJ to program the memory cell to a high resistant state. To program a memory cell to a low resistance state, a write current may be driven from a MTJ to a transistor drain to a transistor source. Unidirectional programming logic may be simpler and more efficient than bidirectional programming logic. Also, the array 102 may be fabricated without a separate transistor for each cell, which further decreases cell size and cost. By utilizing a spin current generator 100 which may generate a spin current polarized in either direction (a bi-spin polarity current), the memory cell component 104 may be programmed with a unidirectional current, as described further below. Further, in certain embodiments, a single-spin polarity current, or a non-polarized spin current may be utilized to program a memory cell component 104 , by adding certain features or layers to the memory cell component 104 , such that the memory cell component 104 is able to exploit the properties of the current to facilitate the changing of the magnetization of a free ferromagnetic layer, therein. For example, in FIG. 2 , if a non-polarized current is passed through the memory cell component 104 , the the pinned layer 106 may reflect the current towards the free layer 108 and switch the magnetization direction of the free layer 108 to the opposite direction of the pinned layer 106 .
One embodiment of the present invention, a spin current generator configured to generate a unidirectional current to adjust polarization direction in a spintronics device, is illustrated in FIG. 3 , where a spin current generator 200 can generate a non-polarized current 212 or a single-spin polarized current 214 . The bidirectional arrows depicting the non-polarized current 212 represent that the current is not yet polarized in any direction. Conversely, the unidirectional arrow depicting the polarized current 214 represent that the current is polarized in one direction (single-spin polarized). The spin current generator 200 includes a spin-polarizing layer 202 , which may comprise ferromagnetic materials, such as Co, Fe, Ni or its alloys, NiFe, CoFe, CoNiFe, or doped alloys CoX, CoFeX, CoNiFeX (X=B, Cu, Re, Ru, Rh, Hf. Pd, Pt, C), or other half-metallic ferromagnetic material such as Fe3O4, CrO2, NiMnSb and PtMnSb, and BiFeO, for instance. The spin current generator 200 may also include a nonmagnetic layer 204 which may be nonconductive and include some combination of AlxOy, MgO, AlN, SiN, CaOx, NiOx, HfO2, Ta2O5, ZrO2, NiMnOx, MgF2, SiC, SiO2, or SiOxNy, for example, or conductive and include some combination of Cu, Au, Ta, Ag, CuPt, CuMn or other nonmagnetic transition metal, for example. The spin-polarizing layer 202 and the nonmagnetic layer 204 may be isolated from a material 206 by an insulative material 208 . In some embodiments, the material 206 may generate heat (“heater material”), and in other embodiments, the material 206 may comprise piezoelectric materials (“piezoelectric material”).
In some embodiments, the material 206 may incorporate some combination of heat generating and piezoelectric materials, or the material 206 may comprise more than one heat generating and/or piezoelectric material. As used in the present specification, the term “layer” refers to materials formed in parallel, with one material disposed over another (e.g., layers 204 , 202 , and 210 of FIG. 3 ). In contrast other materials, not referred to as layers, may be formed perpendicular to a stack of parallel materials (e.g., layers 206 and 208 are perpendicular to layers 204 , 202 , and 210 of FIG. 3 ), as spacers other structures formed adjacent to the layers. As also used herein, it should be understood that when a layer is said to be “formed on” or “disposed on” another layer, the layers are understood to be parallel to one another, but there may be intervening layers formed or disposed between those layers. In contrast, “disposed directly on” or “formed directly on” refers to layers in direct contact with one another. Similarly, if materials are said to be “adjacent” to other materials, the materials are in the same cross-sectional plane (e.g., the layer 206 is adjacent to the layers 202 , 204 and 210 ). Further, if a material is said to be adjacent to another material or layer, there may be intervening materials therebetween, while “directly adjacent,” connotes no intervening materials therebetween.
Since heat decreases magnetization and spin-polarization efficiency in magnetic materials, a heater material 206 may apply heat to decrease or eliminate the magnetization or spin polarization of the spin-polarizing layer 202 , and the spin current generator 200 may output a non-polarized or less spin polarized current 212 . Specifically, when voltage is applied to the spin current generator 200 through the transistor 216 , the heater material 206 may heat up the spin-polarizing layer close to or above its curie temperature, which may be in a range of approximately 160° C. to 300° C. The spin-polarizing layer 202 would then substantially lose its magnetization, and current would be non-polarized or not highly polarized after it passes through the demagnetized spin-polarizing layer 202 . The spin-polarizing layer 202 may retain its magnetization through an exchange interaction with the antiferromagnetic layer 210 when the spin-polarizing layer 202 is cooled to approximately room temperature. Thus, the spin current generator 200 may produce a unidirectional non-polarized current to program a spintronics device. One example of how a unidirectional non-polarized current may program a spintronics device is to pass non-polarized current that becomes spin polarized by magnetic layers of fixed magnetization in a spintronics device. Further, magnetic layers may be switched by reflected currents polarized by other layers in a spintronics device.
Alternatively, the spin current generator 200 may produce polarized current 214 of various polarization degrees through a transient stress effect induced by the piezoelectric stress material 206 . The piezoelectric stress material 206 may apply varying stress to adjust the spin polarization of the spin-polarizing layer 202 . When voltage is applied to the piezoelectric stress material 206 through the transistor 216 , the piezoelectric stress material 206 may induce a stress that modulates the spin-polarization efficiency of the spin-polarizing layer 202 such that the current output of the spin current generator 200 may be polarized to a desired degree.
Specifically, the spin polarization degree of the output current is determined by the spin-polarization efficiency of the spin-polarizing layer 202 , which may be adjusted by either heat or stress to the spin-polarizing layer 202 . If the spin current generator 200 sends a polarized current 214 to a spintronics device, voltage may be applied to the spin current generator 200 , and the piezoelectric material 206 may generate a transient stress in the spin-polarizing layer 202 . The transient stress influences the spin-polarization efficiency of the spin-polarizing layer 202 , which affects the degree of polarization of the output current. Thus, embodiments in accordance with the present technique may produce unidirectional single-spin polarized current to switch the magnetization of a spintronics device. The direction of the spin current that may be output by the spin current generator 200 is dependent on the arrangement of the transistor 216 , as will be appreciated.
The heater material 206 may comprise refractory metals including, for example, nitride, carbide, and Boride, TiN, ZrN, HfN, VN, NbN, TaN, TiC, ZrC, HfC, VC, NbC, TaC, TiB2, ZrB2, HfB2, VB2, NbB2, TaB2, Cr3C2, Mo2C, WC, CrB2, Mo2B5, W2B5, or compounds such as TiAlN, TiSiN, TiW, TaSiN, TiCN, SiC, B4C, WSix, MoSi2, or elemental materials such as doped silicon, carbon, Pt, Niobium, Tungsten, molybdenum, or metal alloys such as NiCr, for example. In some embodiments, the piezoelectric material 206 may be composed of a conductive piezoelectric material, such as (TaSe4)2I, multi-layered AlxGa1-xAs/GaAs, BaTiO3/VGCF/CPE composites, or other piezoelectric/conductive material composites. In other embodiments, the piezoelectric material 206 may be an insulative material, such as berlinite (AlPO 4 ), quartz, gallium orthophosphate (GaPO 4 ), langasite (La 3 Ga 5 SiO 14 ), ceramics with perovskite or tungsten-bronze structures such as barium titanate (BaTiO 3 ), SrTiO3, bismuth ferrite (BiFeO 3 ), lead zirconate titanate (Pb[Zr x Ti 1-x ]O 3 0<x<1), Pb 2 KNb 5 O 15 , lead titanate (PbTiO 3 ), lithium tantalate (LiTaO 3 ), sodium tungstate (Na x WO 3 ), potassium niobate (KNbO 3 ), lithium niobate (LiNbO 3 ), Ba 2 NaNb 5 O 5 , and other materials such as ZnO, AlN, polyvinylidene fluoride (PVDF), lanthanum gallium silicate, potassium sodium tartrate, sodium potassium niobate (KNN). The nonmagnetic layer 204 may insulate the magnetic layers of the spin current generator 200 from other magnetic layers and may be either conductive or nonconductive. The conductive nonmagnetic layer 204 may comprise Cu, Au, Ta, Ag, CuPt, CuMn, or other nonmagnetic transition metals, or any combination of the above nonmagnetic conductive materials. The nonconductive nonmagnetic layer 204 may comprise Al x O y , MgO, AlN, SiN, CaO x , NiO x , HfO 2 , Ta 2 O 5 , ZrO 2 , NiMnO x , MgF 2 , SiC, SiO 2 , SiO x N y , or any combination of the above nonmagnetic nonconductive materials.
Another embodiment of the present invention is illustrated in FIG. 4 , where a spin current generator 300 can generate arbitrary spin current or spin current polarized in either direction (bi-spin polarity). As used in the present specification, arbitrary spin current refers to spin current polarized in either direction with any desired polarization degree. The spin current generator 300 uses two structures 302 and 304 of opposite magnetization. Each structure has a respective spin polarizing layer 306 and a nonmagnetic layer 308 . The spin-polarizing layer 306 in the structures 302 and 304 have opposite magnetizations, and this enables the spin current generator 300 to generate current spin-polarized in an arbitrary degree for a spintronics device, or in a specified direction based on the selection of the appropriate transistor 314 or 316 . The spin current generator 300 may be employed in applications and systems benefiting from a spin current generator capable of producing a bi-spin polarity current (i.e., a current with a spin-polarity in either direction), such as the memory cells of FIG. 1 .
For example, if a memory cell (as in FIG. 2 ) is selected to be programmed to a low resistance state, a current would pass through the structure 304 of the spin current generator 300 , via the transistor 316 , where the spin-polarizing layer 306 polarizes the spin of the electrons to the left. The spin current generator 300 then outputs a programming current spin polarized to the left 310 , and the left-polarized current 310 switches the magnetization of free layer 108 (of FIG. 2 ) to the left, parallel to the pinned layer 106 , writing the cell in a low resistance state. If a memory cell is selected to be programmed to a high resistance state, a current would pass through the structure 302 of the spin current generator 300 , via the transistor 314 , where the spin-polarizing layer 306 polarizes the spin of the electrons to the right. The programming current is spin polarized to the right 312 , and the right-polarized current 312 switches the magnetization of free layer 108 to the right, antiparallel to the pinned layer 106 , writing the cell in a high resistance state.
The spin-polarizing layer 306 may comprise ferromagnetic materials, such as Co, Fe, Ni or its alloys, NiFe, CoFe, CoNiFe, or doped alloys CoX, CoFeX, CoNiFeX (X=B, Cu, Re, Ru, Rh, Hf, Pd, Pt, C), or other half-metallic ferromagnetic material such as Fe3O4, CrO2, NiMnSb and PtMnSb, and BiFeO, for instance. The nonmagnetic layer 308 may insulate the magnetic layers of the spin current generator 300 from other magnetic layers and may be either conductive or nonconductive. The conductive nonmagnetic layer 308 may comprise Cu, Au, Ta, Ag, CuPt, CuMn, or other nonmagnetic transition metals, or any combination of the above nonmagnetic conductive materials. The nonconductive nonmagnetic layer 308 may comprise Al x O y , MgO, AlN, SiN, CaO x , NiO x , HfO 2 , Ta 2 O 5 , ZrO 2 , NiMnO x , MgF 2 , SiC, SiO 2 , SiO x N y , or any combination of the above nonmagnetic nonconductive materials.
This embodiment and other embodiments in accordance with the present technique may be used in spintronics applications, or in conjunction with or incorporated in any device using electron spin properties. As an example, STT-MRAM cells are programmed into low or high resistance states by switching the magnetization of a free ferromagnetic layer in the memory cell. As previously discussed, the memory cell is programmed to a low resistance state when a programming current switches the magnetization of the free layer to be parallel with the magnetization of a pinned layer in the STT-MRAM cell. The memory cell is programmed to a high resistance state when a programming current switches the magnetization of the free layer to be antiparallel with the magnetization of the pinned layer in the STT-MRAM cell. The typical STT-MRAM cell is structured with bidirectional programming logic, as the free layer requires programming current polarized in both directions, depending on the resistance state it will be switched to. In the embodiments of the present technique, a spin current generator capable of generating current polarized in either direction, or not polarized at all, may allow for simpler unidirectional programming logic in the STT-MRAM cell or other spintronics components.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
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Spin current generators and systems and methods for employing spin current generators. A spin current generator may be configured to generate a spin current polarized in one direction, or a spin current selectively polarized in two directions. The spin current generator may by employed in spintronics applications, wherein a spin current is desired.
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TECHNICAL FIELD
[0001] The invention relates to the production of a floor covering from polymer particles (flakes, vermicelli, grains, etc.) which may cover a very wide range of appearances, including a homogeneous product appearance that has a perfectly smooth and uniform surface.
BACKGROUND
[0002] In the field of floor coverings, resilient products, usually based on PVC, enjoy great success, in a large part due to the variety of decorative possibilities that they permit. Indeed it is possible to print them, to produce chemical or mechanical embossing optionally in connection with printed designs, to produce material effects by combining various types of particles, resulting in graining, imitations of stones or other mineral or more generally natural effects.
[0003] Regarding these material appearances which increasingly appeal to the public and to which the invention relates, two techniques coexist.
[0004] The first, which results in the formation of the family of products known as “homogeneous products” comprises the following steps:
1 Extruding a certain number of films having different colors or mattness from a thermoplastic material, generally PVC 2 Mechanically granulating these films in order to obtain particles having more or less spherical shapes of the order of 5 mm in diameter (function of the final thickness of the product) 3 Mechanically mixing these particles as a function of the appearance desired for the finished product and distributing them on a conveyor using a Villars® type dispenser. In general, a deposition of a single layer of particles is aimed for, that is to say that particles are all in contact with the conveyor and only overlap very little. Since standard dispensers do not permit a deposition that is that uniform, in order to achieve this objective the conveyor may be subjected to vibrations, as the particles are free, the “overflow” may be discharged via the edges of the conveyor. 4 Introducing this assembly of particles into a Hymmen® type double-belt press. These machines act as a calender but make it possible to keep the particles at the desired softening point of the thermoplastic material for several seconds by gradually compressing it. They therefore avoid deforming the particles too much and creating (directional) line effects in the finished product. During the softening under high pressure (up to 40 bar) the particles based on the same thermoplastic material agglomerate with one another, their peaks are crushed so that the product formed has the appearance of a continuous film with perfectly smooth surfaces.
[0009] Each particle, with its color or mattness characteristics, nevertheless remains visible as is, although deformed, which gives the product its specific appearance.
[0010] This product is constituted of a single homogeneous layer of materials (homogeneous since being of the same chemical nature), hence its name.
[0011] When this material is subjected to traffic as a floor covering, its wear will not give rise to a variation in appearance since the product is, by construction, also homogeneous in its thickness (a single layer of particles deposited on the conveyor).
[0012] These products do not therefore intrinsically need additional protection with respect to the traffic linked to their use, that is to say, as for products based on plastisol (see below), a wear layer (or smoothing layer) generally deposited in liquid form at the end of the production process, then gelled in an oven.
[0013] These products make up a family that is highly valued for its strength qualities.
[0014] The particles may have a wide range of colors or mattness. Different esthetic effects may be obtained by varying the diameter of the particles, or even by mixing particles of different diameters.
[0015] Sophisticated embodiments exist which consist in producing relatively coarse designs via a system of covers or drawers arranged below dispensers or in using particles of uncommon sizes or shapes, as is described in patent EP 1838510.
[0016] Nevertheless, it remains impossible, with this technique, to combine particles of different chemical natures and even less mineral or metallic particles, nor particles of non-spherical flake type since these particles will inevitably be deformed during the process. The esthetic range linked to this process is therefore greatly limited.
[0017] The second, which results in the formation of the family of products known as “heterogeneous” products is based on the use of plastisol (mixture of PVC, plasticizer and optionally filler) which is in a liquid form.
[0018] In order to form products known as “heterogeneous” products:
1 Using a doctor blade or rolls or any other suitable means, a first liquid layer of colored plastisol, opaque plastisol or transparent, and therefore unfilled, plastisol (whereas a normal plastisol is 50% filled with, in general, calcium carbonate) is deposited on a substrate which may be, for example, a calendered film reinforced with a web of glass fibers. 2 Particles are then sprinkled over this layer of plastisol using a dispenser, for example of Villars® type. 3 At this stage, the penetration of the particles into the plastisol is not controlled. The particles remain predominantly at the surface, thus creating a random relief. 4 Furthermore, it is impossible to obtain a single-layer type deposition (no vibration possible due to the viscosity of the plastisol) and if it is attempted to remove the excess particles via suction for example, they will inevitably be contaminated by the plastistol which will make them unable to be recycled and will create multiple pollution problems. 5 The product is then pre-gelled. This is to say that it passes under an infrared assembly or into an oven, which will enable a first curing of the plastisol, therefore setting the particles. 6 A new layer of transparent plastisol known as smoothing plastisol is then deposited, the role of which will be to seal the product, that is to say to fill in the voids between the particles or the surface irregularities that the dropping thereof has inevitably caused in the plastisol medium. This plastisol, which is unfilled or not filled very much, is therefore expensive. Furthermore, it is never strictly speaking perfectly transparent and will therefore cause a “milky” haze on top of the decoration produced by the particles. 7 This deposition is followed by a gelling in an oven which will ensure the definitive cohesion of the covering.
[0026] These two succinct descriptions therefore clearly make it possible to comprehend the advantages and drawbacks of each of these two families of products.
[0027] Homogeneous products do not require a transparent smoothing (or wear) layer but remain limited esthetically due to the restricted type of particles that can be used, (due, in particular, to their deformation), whilst heterogeneous products based on plastisol, although they can use particles of all shapes and natures by blending them with one another, require a large supply of “transparent” plastisol which is therefore expensive since it is lightly filled, which will furthermore blur the reading of the decoration, and also a wear layer based on PU, and therefore also expensive.
[0028] With this second technique, appearances close to homogeneous are also impossible to achieve due to the plastisol/dispenser combination which does not allow the deposition of a single layer.
[0029] The read quality of the decoration is poorer than in the case of homogeneous products due to the addition of the smoothing plastisol, the particles never strictly speaking being at the surface of the covering.
[0030] Finally, the current processes using plastisol require a large number of separate successive steps that it is necessary to control individually and which generally increase the production costs.
[0031] To date, these techniques have therefore remained complementary, each being confined to its esthetic and economic range.
BRIEF SUMMARY
[0032] The invention proposes a single technique that makes it possible to obtain a large number of esthetic appearances linked to the use of particles while also benefiting from a perfectly smooth surface finish, even without resorting to a supplementary wear layer.
[0033] The invention also provides a device that makes it possible to obtain such a novel floor covering, and also the covering itself.
[0034] The invention is essentially based on two observations that are surprising for a person skilled in the art.
[0035] First, the quality of surface finish characteristic of homogeneous products may be obtained with pressure levels well below the levels generally required during the formation of such products.
[0036] Specifically, it is advisable, at the moment when what is still only a bed of particles passes into the Hymmen® type double press machine, to distinguish between, on the one hand, the thermodynamic conditions necessary for the adhesion of the particles to one another and therefore the formation of the cohesive film and, on the other hand, the thermodynamic conditions necessary for obtaining a smooth surface.
[0037] As regards the adhesion conditions in the case of homogeneous products, a temperature generally of the order of 160° C. and a pressure of the order of 20 to 40 bar are required in order to deform and sufficiently press the particles against one another. Specifically, not being able to go up to the melting point, which would lead to a mixing of the colors and a total loss of the integrity of the particles, it is necessary to compensate via a very high pressure level.
[0038] It has been determined during laboratory tests using the same type of granules as in homogeneous products that the pressure necessary to obtain a surface that is smooth or at least uniform (since a light embossing of the surface may be desired in order to increase the mattness) and therefore conforming to the surface finish of the belt in contact with the product, was between 1 and 2.5 bar, i.e. well below the pressure for formation of the homogeneous product itself.
[0039] These first tests made it possible to obtain products having the appearance of homogeneous products, i.e. a perfectly smooth film, but of course without sufficient cohesion: the particles detached from one another during handling.
[0040] Since the two phenomena of formation, in the form of a film, of the product and its surface smoothing take place simultaneously in the same machine, it had been wrongly concluded therefrom that they required the same operating conditions.
[0041] The second surprising observation based on the present invention is that the known technique using plastisol may be adapted advantageously in order to obtain products that combine the advantages of this technique with those of a process for the manufacture of homogeneous products.
[0042] Specifically, as indicated above, to date, these two techniques were completely separate and it is generally accepted that they were hardly able to converge due to fundamental differences at the heart thereof.
[0043] During research which led to the present invention, the inventors observed that by keeping the first step of the heterogeneous process using plastisol, namely the distribution of particles over a liquid plastisol layer and by carrying out a gelling or at least a pregelling, it is possible to obtain an advantageous result by using a low pressure of around 2 bar. Indeed, this pressure level proves sufficient to guarantee an excellent surface finish whereas a temperature around 180° C. will allow the pregelling of the plastisol and therefore a perfect adhesion of the particles within the plastisol and the cohesion of the product itself. A definitive gelling may be in fine obtained by conventional means, such as by gelling rolls or ovens (infrared or gas ovens, for example).
[0044] In conclusion, the present invention makes it possible to obtain a thermoplastic floor covering which, in its simplest form, is a homogeneous type covering with the advantages that are associated therewith, mainly a greater wear resistance in the sense that the appearance does not degrade during use, even without a supplementary wear layer, and also a simpler and more economical method of manufacture. Indeed, in a floor covering obtained with the process of the present invention, the particles are side by side as in the case of a homogeneous type covering.
[0045] Moreover, the invention also makes it possible to benefit from the advantages specific to plastisol coverings by offering a greater variability as regards the appearance, and also the production of floor coverings of heavier quality, possessing, where appropriate, a textile sublayer, etc.
[0046] One particular additional advantage of the present invention is that the device or the machine that enables this pregelling at low pressure may comprise two heat-resistant, preferably Teflon-coated conveyor belts, having variable lengths depending on the pregelling time, as a function of the amount of plastisol deposited and the desired production rates.
[0047] In such a machine, said particles of materials are deposited directly onto a layer of plastisol on a heat-resistant conveyor belt or on a support material placed on the latter. This layer then successively passes through a preheating section, heating section and cooling section of a treatment zone of an installation designed to carry out said process. The device preferably enables a guidance system of the upper conveyor belt to be adjusted and secured in a vertical direction.
[0048] Mention may be made, as a machine which may be suitable, with certain adaptations, for the present process of the machine sold under the trademark Thermofix® by the German company Schilling-Knobel GmbH, in particular those described in U.S. Pat. No. 6,217,700 or in patent EP 1 045 751.
[0049] Indeed, to date, these machines were designed and used in the industrial context solely for the use of “dry blend” type powder, but they could fulfill the required conditions (double belts, pressure levels) with certain adaptations appropriate for liquid resins, such as plastisol (doctor blade, roll, suitable gum, etc.).
[0050] But of course other machines that intrinsically permit a higher pressure level may be used, such as the AUMA® type machines constituted of a heating roll and of a belt that adopts around a half circumference of the roll or the Hymmen® type machines described previously.
DETAILED DESCRIPTION
[0051] The present invention therefore proposes a process for manufacturing a novel thermoplastic floor covering comprising the following steps:
[0052] (a) depositing a layer of a liquid component onto a support;
[0053] (b) sprinkling solid particles onto the layer of liquid component; and
[0054] (c) applying pressure and heat in order to form a floor covering that has a smooth surface.
[0055] The step of applying pressure and heat (c) is preferably carried out between two, lower and upper, conveyor belts, more preferably in a double-belt press. The pressure exerted on the floor covering is preferably low and generally lies between 0.05 and 8 bar, preferably between 0.1 and 5 bar and particularly preferably between 0.15 and 3 bar.
[0056] In general, the layer of liquid component has a thickness between 0.5 mm and 3 mm.
[0057] The liquid component is chosen, within the context of the present invention, from a plastisol, an organosol or an emulsion of SBR rubber.
[0058] Preferably plastisol is used. The plastisols that can be used are generally those known to a person skilled in the art, that are optionally transparent or translucent, and compatible with the particles used, for example mixtures based on PVC and plasticizers.
[0059] The component may also be an organosol (mixture based on plasticizer(s) and compatible polymers) which more generally may be suitable for the invention, such as for example the organosols based on PMMA (polymethyl methacrylic acid) or acrylic.
[0060] Certain polymers in the form of emulsion may also be suitable, such as SBRs (styrene butadiene rubbers): reference will then be made to crosslinking rather than gelling.
[0061] Within the present document, the term “plastisol” may therefore as a variant be replaced by the terms “organosol” or “SBR emulsion” and the present invention therefore also relates to these variants. As suggested below, in the case of SBR emulsions, the term “to gel” and also the related terms should be read as having the meaning of “to crosslink”.
[0062] The granules or solid particles that can be used within the context of the present invention are particulate materials comprising thermoplastic materials for example, but not exclusively, polyvinyl chloride (PVC), polyolefilns, polyamides or mixtures thereof, but also particles of mineral or metallic origin. The granules used for the manufacture of a floor covering may be of different nature and/or appearance as long as they are compatible with the plastisol used.
[0063] The amount of particles used may vary from 0 to 60% by weight of the plastisol layer+granules, preferably from 1 to 20% by weight as a function of the appearance and of the other desired properties. The ratio of particles to plastisol is chosen so that the particles, after the processes, are well coated by the gelled plastisol so as to be able to obtain a cohesive surface.
[0064] The size of the particles obviously depends on the thickness of the desired floor covering and consequently on the thickness of plastisol applied. Generally, the largest dimension of the granules does not exceed (significantly) that anticipated for the final covering. Their shape is not, on the other hand, crucial, but makes it possible to vary, further still, the possible decorations.
[0065] The deposition of plastisol may be carried out directly on the lower conveyor belt or onto a support placed on the latter. This support may be removable in order to be detached from the floor covering at the end of the process or subsequently, for example a “release” type paper or any other equivalent means known to a person skilled in the art.
[0066] The support may also be an integral part of the finished floor covering if so desired. In this case, it will be referred to as a sublayer which is chosen, for example, from a calendered sublayer, a textile, a nonwoven fabric, etc., especially made of glass fibers, polyester, natural fibers, etc.
[0067] The process according to the invention advantageously comprises a pregelling step between the step (b) of sprinkling particles onto the layer of liquid plastisol and the step (c) of applying pressure and heat.
[0068] The time necessary for the various steps of the process depends on the nature and on the amount of plastisol and particles deposited, but also on the temperature and the pressure used. As the pressure is relatively low and as the gelling temperature should not exceed a certain threshold in order not to completely melt the granules, it is possible to adapt the speed of the conveyor belts and/or their length as a function of the other parameters.
[0069] Another aspect of the invention relates to a device, in particular, for carrying out the process for manufacturing a thermoplastic floor covering as described above, comprising (a) a lower conveyor belt, (b) an upper conveyor belt placed above a portion of the lower conveyor belt (a) and at a distance from the latter which corresponds to the thickness of the floor covering and that makes it possible to exert a pressure on this floor covering, (c) a heating zone followed by (d) a cooling zone, and also upstream of the heating zone (c), (e) a plastisol applicator, followed by (f) a particulate material applicator above the lower conveyor belt (a).
[0070] The distance between the two conveyor belts (a) and (b) can preferably be adjusted as a function of the thickness of the chosen floor covering. The upper conveyor belt (b) may be designed in a floating manner in order to control the pressure exerted on the floor covering.
[0071] The device optionally comprises a supplementary heating zone (g) (preheating or pregelling zone) before and/or after the particulate material applicator (f) enabling pregelling of the plastisol.
[0072] The plastisol applicator or distributor (e) may be of any known type and preferably comprises a doctor blade and/or one or more rolls. One particularly suitable plastisol applicator makes it possible to deposit a layer of plastisol having a thickness between 0.5 mm and 3 mm. In the case of the use of a support intended to be integrated into the covering, it may be advantageous to carry out the application of plastisol in more than one step, for example by means of a plastisol applicator (e) having two different application zones, separated for example by a supplementary heating zone, in order to pretreat the support. The plastisol applied in the first step, then pregelled then acts as a size for the support.
[0073] The applicator of particulate materials (f) may be in its simplest form a dispenser of granules, flakes, etc. of a single type or appearance, but it may generally be advantageous to be able to apply several types of granules of different appearance, size, nature and/or color, either as a mixture, or successively.
[0074] As already indicated above for the process according to the invention, the device may also comprise (h) a support applicator upstream of the plastisol applicator (a). The support may in this case be removable from the finished floor covering, for example a “release” type paper, or may be an integral part of the floor covering in the form of a firmly attached sublayer, preferably a calendered sublayer, a textile, a nonwoven fabric or a glass web.
[0075] A last aspect of the invention is a thermoplastic floor covering as described above. Advantageously, this is obtained by a process or by means of a device as described previously and comprises solid particles integrated into a gelled plastisol layer, the upper surface of which is essentially smooth.
[0076] As a function of the properties desired for the floor covering, it is also possible to apply it to a substrate, independently of the use of an integrated support, especially to a flexible substrate, for example a layer of foam, or to a rigid substrate, for example made of wood in pure, laminated or pressed form or in the form combined with plastics (composites) or made of a rigid plastic, for example of extruded polypropylene type, etc.
[0077] Finally, even when the floor coverings of the present invention do not a priori need a supplementary wear layer, it may be advantageous or desirable to apply such a supplementary layer, for example having a thickness of a few micrometers based on polyurethane, thereto, for example to further improve the protection against stains.
[0078] Other features and characteristics of the invention will emerge from the example below.
Examples
[0079] Example of a product (floor covering) structure
[0080] From bottom to top: 1 mm calendered sublayer of glass web-1 mm of plastisol to a total thickness of 2 mm.
[0081] Description of the structure: heterogeneous product with decoration in the bulk including an incorporation of particles at the surface without addition of transparent wear layer.
[0082] Procedure for the Structure
[0083] Unwinding of the calendered sublayer—coating of 1 mm of plastisol (for example opaque plastisol) onto the glass web (as a variant, it is possible to “seal” the glass web with a first deposition of 200 μm followed by a gelling pass, then by depositing an 800 μm layer by doctor blade or reverse roll)—distribution of the flakes—passing through an infrared (IR) oven or through a thermal oven—passing into a low-pressure double-belt press (for example of modified Thermofix® type)—optional embossing—optional deposition of a PU finishing layer.
[0084] Parameters of the low-pressure double-belt press
Heating zone: 3 m Top/bottom zone temperature: 190° C. Speed: 0.6 m/min Pressure: 4 bar (but by comparison with the pressure of a double steel belt press the pressure is rather <1 bar)
[0000]
Plastisol formulation
Lacovyl PB 1805 (PVC)
1500.0
Lacovyl PB 1202 (PVC)
750.0
Vinnolit C 66 W (PVC)
750.0
DIHP (plasticizer)
975.0
Viscosity reducer
225.0
Stabilizer
75.0
Epoxidized soybean oil
60.0
RC 82 (titanium)
130.0
[0000]
Flake formulation
Minex S 40 (transparent filler)
270
Stabilizer
180
DINP (plasticizer)
1020
Epoxidized soybean oil
135
Etinox 630 (PVC)
4560
Anti-static agent
60
Mic Red BRN - AQ (20%) (pigment)
0.495
Mic White 220 NQ - F (pigment)
59.565
Mic Blue 138 AQ (GLP - AQ) 20% (pigment)
0.435
Mic Black SRF - NQ F 30% (pigment)
3.675
[0089] The floor covering obtained has a very smooth surface and high cohesion.
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The invention relates to a method for making a ground coating made of a thermoplastic material, that comprises the steps of (a) depositing a layer of a liquid component on a substrate, the liquid component being selected from a plastisol, an organosol or an SBR rubber emulsion, (b) powdering solid particles on the liquid component layer, and (c) applying press heat in order to form a ground coating having a smooth surface. The invention also relates to a device for obtaining such coatings.
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CROSS-REFERENCE TO RELATED APPLICATION
The present patent application/patent claims the benefit of priority of U.S. Provisional Patent Application No. 61/433,736, filed on Jan. 18, 2011, and entitled “BONE PLATE INCORPORATING A STATIC/DYNAMIC COMPRESSION MECHANISM AND ASSOCIATED SURGICAL METHODS,” the contents of which are incorporated in full by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to bone plates for stabilizing and partially or wholly immobilizing bone fragments, adjacent vertebrae, or the like while providing the application of constant static compression intra-operatively and constant static or dynamic compression post-operatively.
BACKGROUND OF THE INVENTION
In the treatment of various orthopedic and spinal ailments and defects, it is desirable to stabilize or partially or wholly immobilize two or more bony segments, with bone arthrodesis or fusion being the desired outcome. By applying compressive force across the site, bone growth is enhanced according to Wolff's law. This is believed to decrease healing time and increase fusion quality.
Similarly, in the treatment of fractures and other orthopedic conditions, stabilizing or immobilizing devices are often placed on bone fragments to maintain bony alignment and impart stability to promote healing. Healing can be further promoted by creating compression across the fracture site intra-operatively and, ideally, allowing dynamic compression across the fracture site post-operatively.
Specifically, spinal fusion is one example of a surgical procedure that is used to stabilize or immobilize adjacent vertebrae in the treatment of an injury or degenerative condition. During the procedure, the intervertebral disc is removed and the intervertebral space is filled with bone graft material and/or a fusion cage. A bone plate is typically used to provide stability to the affected spinal segment, keeping the bone graft material and/or fusion cage in place and providing rigidity.
Often, however, the bone graft material or the bony fragments exhibit bone resorption, which is the process of osteoclasts breaking down the bone and releasing minerals into the bloodstream. As the bone graft material resorbs, there is a loss of contact with the host bone and less compression of the bone graft material, leading to progressively less likelihood of incorporation and healing of the fusion. This process is usually the result of a lack of stimulus for bone maintenance, i.e. compression. This also leads to an exponentially increased load on the bone plate, resulting in an increased occurrence of failed implants, which typically requires revision surgery and means longer recovery times for patients.
The use of a bone plate that allows for dynamic compression post-operatively would enhance the bone arthrodesis process. Dynamic compression would stimulate the healing of the bone graft material to the host bone, resulting in a more rapid and solid fusion. In the case where the bone graft material undergoes resorption or a fusion cage is compromised, dynamic compression would allow for the vertebral column to shift axially, thus promoting the maintenance of bony contact and compression stimulus at the arthrodesis site. In a worst case where the bone graft material completely resorbs and adjacent host bones are then touching, compression stimulus is still applied and arthrodesis can still take place, thereby imparting spinal stability.
BRIEF SUMMARY OF THE INVENTION
In various exemplary embodiments, the present invention provides a bone plate that includes a sliding mechanism that allows for both static and dynamic loading and the associated stabilization or partial or whole immobilization of two or more adjacent bone fragments or vertebral bodies of the spine. This sliding mechanism is designed such that as bone resorbs or the like, the sliding mechanism maintains axial compression in a collinear manner across the bone segments.
In one exemplary embodiment, the present invention provides a bone plate incorporating a compression mechanism, including: a plate structure defining a plurality of screw receiving plate holes and a plurality of screw receiving plate slots; and a carriage assembly engaging the plurality of screw receiving plate slots, wherein the carriage assembly translates axially with respect to the plate structure via the plurality of screw receiving plate slots, thereby providing the compression mechanism. The plurality of screw receiving plate holes receive and retain a plurality of screws that pass through the plate structure and into a first bony structure disposed beneath the plate structure, thereby securing the plate structure to the first bony structure. The carriage assembly includes a plurality of screw receiving carriage assembly stems and an elongate member that joins the plurality of screw receiving carriage assembly stems. The plurality of screw receiving carriage assembly stems receive and retain a plurality of screws that pass through the carriage assembly and into a second bony structure disposed beneath the carriage assembly, thereby securing the carriage assembly to the second bony structure. The plurality of screw receiving plate slots translatably receive the plurality of screw receiving carriage assembly stems. The plurality of screw receiving carriage assembly stems are axially translated with respect to the plate structure in unison and in parallel with respect to one another. The plurality of screw receiving carriage assembly stems prevent rotation of the carriage assembly with respect to the plate structure when the carriage assembly is translated with respect to the plate structure. The carriage assembly translates axially with respect to the plate structure, thereby changing the relative position of a plurality of screws associated with the plate structure and a plurality of screws associated with the carriage assembly, without changing the axial length of the bone plate. The bone plate provides for axial translation of a first bony structure secured to the plate structure with respect to a second bony structure secured to the carriage assembly in a laterally and rotationally constrained manner. The bone plate provides dynamic compression between a first bony structure secured to the plate structure and a second bony structure secured to the carriage assembly.
In another exemplary embodiment, the present invention provides a bone plate incorporating a compression mechanism, including: a plate structure defining a plurality of screw receiving plate holes and a plurality of screw receiving plate slots; and a carriage assembly engaging the plurality of screw receiving plate slots, wherein the carriage assembly translates axially with respect to the plate structure via the plurality of screw receiving plate slots, thereby providing the compression mechanism; wherein the plate structure is secured to a first bony structure using a plurality of screws; wherein the carriage assembly is secured to a second bony structure using a plurality of screws; and wherein the engagement of the plate structure and the carriage assembly provides dynamic compression between the first bony structure and the second bony structure. The plurality of screw receiving plate holes receive and retain the plurality of screws that pass through the plate structure and into the first bony structure disposed beneath the plate structure, thereby securing the plate structure to the first bony structure. The carriage assembly includes a plurality of screw receiving carriage assembly stems and an elongate member that joins the plurality of screw receiving carriage assembly stems. The plurality of screw receiving carriage assembly stems receive and retain the plurality of screws that pass through the carriage assembly and into the second bony structure disposed beneath the carriage assembly, thereby securing the carriage assembly to the second bony structure. The plurality of screw receiving plate slots translatably receive the plurality of screw receiving carriage assembly stems. The plurality of screw receiving carriage assembly stems are axially translated with respect to the plate structure in unison and in parallel with respect to one another. The plurality of screw receiving carriage assembly stems prevent rotation of the carriage assembly with respect to the plate structure when the carriage assembly is translated with respect to the plate structure. The carriage assembly translates axially with respect to the plate structure, thereby changing the relative position of the plurality of screws associated with the plate structure and the plurality of screws associated with the carriage assembly, without changing the axial length of the bone plate. The bone plate provides for axial translation of the first bony structure secured to the plate structure with respect to the second bony structure secured to the carriage assembly in a laterally and rotationally constrained manner.
In a further exemplary embodiment, the present invention provides a bone plate incorporating a compression mechanism, including: a plate structure defining a plurality of screw receiving plate holes and a plurality of screw receiving plate slots; and a carriage assembly engaging the plurality of screw receiving plate slots, wherein the carriage assembly translates axially with respect to the plate structure via the plurality of screw receiving plate slots, thereby providing the compression mechanism; wherein the plate structure is secured to a first bony structure using a plurality of screws; wherein the carriage assembly is secured to a second bony structure using a plurality of screws; and wherein the carriage assembly is locked to the plate structure during implantation. The carriage assembly is subsequently unlocked from the plate structure subsequent to implantation to provide dynamic compression between the first bony structure and the second bony structure. Optionally, the carriage assembly is subsequently locked to the plate structure subsequent to implantation after a compressive load is applied between the carriage assembly and the plate structure to provide static compression between the first bony structure and the second bony structure. The bone plate is implanted through one of an open surgical procedure and a percutaneous surgical procedure, and in one of a single level, double level, and multiple level configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like device components/method steps, as appropriate, and in which:
FIG. 1 is a planar side view illustrating one exemplary embodiment of a single level bone plate of the present invention;
FIG. 2 is a planar front view illustrating the single level bone plate of FIG. 1 ;
FIG. 3 is a planar back view illustrating the single level bone plate of FIGS. 1 and 2 ;
FIG. 4 is another planar front view illustrating the single level bone plate of FIGS. 1-3 , highlighting translation of the carriage assembly;
FIG. 5 is a disassembled perspective view illustrating the single level bone plate of FIGS. 1-4 ;
FIG. 6 is a planar side view illustrating one exemplary embodiment of a double level bone plate of the present invention;
FIG. 7 is a planar front view illustrating the double level bone plate of FIG. 6 ;
FIG. 8 is a planar back view illustrating the double level bone plate of FIGS. 6 and 7 ; and
FIG. 9 is a flowchart illustrating exemplary embodiments of percutaneous and open surgical procedures for implanting and using the bone plates of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1-5 , in one exemplary (single level) embodiment, the bone plate 10 incorporating a compression mechanism 12 includes a plate structure 14 defining a plurality of screw receiving plate holes 16 and a plurality of screw receiving plate slots 18 . The plate structure 14 has an overall axial length of between about 20 mm and about 36 mm, an overall lateral width of between about 20 mm and about 30 mm, and an overall thickness of between about 1.8 mm and about 3 mm, although other suitable dimensions can be utilized. As used herein, the term “axial” refers to the direction along the bone fragments or bony structures (i.e. fractured bone or vertebrae) to be joined and the term “lateral” refers to the direction that is substantially perpendicular to the “axial” direction. The plate structure 14 has a generally square or rectangular shape with rounded corners and edges, although other suitable shapes can be utilized. The plate structure 14 can be made of titanium, cobalt chrome, or another alloy, although other suitable surgically implantable materials can be utilized. The plurality of holes 16 are each formed through the plate 14 and sized to receive a conventional bone screw or the like, having a locking head or otherwise. Preferably, the plurality of holes 16 each include a conventional screw retention mechanism, such as a lip, c-ring, petal structure, retention plate, or the like, suitable for retaining the bone screws once in place and preventing them from backing out. Upon implantation, the bone screws are disposed through the holes 16 and into an underlying bony structure, thereby securing the plate 14 to the bony structure. In the non-limiting exemplary embodiment illustrated, two holes 16 are provided. The plate 14 can include any number of additional holes 16 , 20 that are desirable as a matter of design choice.
The bone plate 10 also includes a carriage assembly 22 that engages the plurality of screw receiving plate slots 18 . The plurality of slots 18 are each formed through the plate 14 and have an axial length of between about 4 mm and about 8 mm, although other suitable dimensions can be utilized. The carriage assembly 22 includes a plurality of screw receiving stems 24 that are joined by an elongate bridge member 26 . The stems 24 (a pair of which are illustrated in this non-limiting exemplary embodiment) each include a pair of semicircular arcuate members 28 that are separated by opposed notches 30 . The stems 24 are each sized to receive a conventional bone screw or the like, having a locking head or otherwise. Preferably, the stems 24 each include a conventional screw retention mechanism, such as a lip, c-ring, petal structure, retention plate, or the like, suitable for retaining the bone screws once in place and preventing them from backing out. Upon implantation, the bone screws are disposed through the stems 24 and into an underlying bony structure, thereby securing the carriage assembly 22 to the bony structure. In the non-limiting exemplary embodiment illustrated, the stems 24 are disposed through the slots 18 from the bottom of the plate 14 , with the bridge member 26 fitting in a recess manufactured into the bottom of the plate 14 . It will be readily apparent to those of ordinary skill in the art, however, that the stems 24 could be disposed through the slots 18 from the top of the plate 14 , with the bridge member 26 fitting in a recess manufactured into the top of the plate 14 , or the stems 24 could be disposed through the slots 18 from inside the plate 14 , with the bridge member 26 fitting in a recess manufactured into the interior of the plate 14 . Optionally, the screws inserted into the stems 24 are configured to bias the arcuate members 28 outwards such that they impinge on the sides of the slots 18 to a predetermined degree, thereby providing some resistance of the stems 24 to translation within the slots 18 . Further, the bridge member 26 includes a port or screw hole 34 that selectively receives a tool for setting the initial compression provided by the bone plate 10 and/or a screw that rigidly secures the bridge member 26 to the plate 14 (via an additional plate slot 36 or the like), such as intra-operatively or post-operatively, depending upon the preference of the surgeon employing the device.
The carriage assembly 22 translates axially with respect to the plate structure 14 via the plurality of screw receiving plate slots 18 , thereby providing the compression mechanism 12 . The plurality of screw receiving plate holes 16 receive and retain a plurality of screws that pass through the plate structure 14 and into a first bony structure disposed beneath the plate structure 14 , thereby securing the plate structure 14 to the first bony structure. The carriage assembly 22 includes a plurality of screw receiving carriage assembly stems 24 and an elongate member 26 that joins the plurality of screw receiving carriage assembly stems 24 . The plurality of screw receiving carriage assembly stems 24 receive and retain a plurality of screws that pass through the carriage assembly 22 and into a second bony structure disposed beneath the carriage assembly 22 , thereby securing the carriage assembly 22 to the second bony structure. The carriage assembly 22 may also include additional holes for receiving screws, as desired. The plurality of screw receiving plate slots 18 translatably receive the plurality of screw receiving carriage assembly stems 24 . The plurality of screw receiving carriage assembly stems 24 are axially translated with respect to the plate structure 14 in unison, in a collinear manner, and in parallel with respect to one another. The plurality of screw receiving carriage assembly stems 24 prevent rotation of the carriage assembly 22 with respect to the plate structure 14 when the carriage assembly 22 is translated with respect to the plate structure 14 . The carriage assembly 22 translates axially with respect to the plate structure 14 , thereby changing the relative position of the plurality of screws associated with the plate structure 14 and the plurality of screws associated with the carriage assembly 22 , without changing the axial length of the bone plate 10 . The bone plate 10 provides for axial translation of a first bony structure secured to the plate structure 14 with respect to a second bony structure secured to the carriage assembly 22 in a laterally and rotationally constrained manner. Thus, the bone plate 10 provides dynamic compression between thefirst bony structure secured to the plate structure 14 and the second bony structure secured to the carriage assembly 22 .
In effect, the bone plate 10 of the present invention provides multiple levels of screws that are secured to bony fragments or structures that are to be joined. These levels of screws are axially translatable with respect to one another, without varying the axial length of the bone plate 10 . This provides contact maintenance and dynamic compression between the bony fragments or structures as resorption occurs, etc., thereby promoting fusion at the arthrodesis site.
Referring now to FIGS. 6-8 , in another exemplary (double level) embodiment, the bone plate 10 incorporating a compression mechanism 12 includes a plate structure 14 defining a plurality of screw receiving plate holes 16 and a plurality of screw receiving plate slots 18 . The plate structure 14 has an overall axial length of between about 34 mm and about 54 mm, an overall lateral width of between about 20 mm and about 30 mm, and an overall thickness of between about 1.8 mm and about 3 mm, although other suitable dimensions can be utilized. As used herein, the term “axial” refers to the direction along the bone fragments or bony structures (i.e. fractured bone or vertebrae) to be joined and the term “lateral” refers to the direction that is substantially perpendicular to the “axial” direction. The plate structure 14 has a generally rectangular shape with rounded corners and edges, although other suitable shapes can be utilized. The plate structure 14 can be made of titanium, cobalt chrome, or another alloy, although other suitable surgically implantable materials can be utilized. The plurality of holes 16 are each formed through the plate 14 and sized to receive a conventional bone screw or the like, having a locking head or otherwise. Preferably, the plurality of holes 16 each include a conventional screw retention mechanism, such as a lip, c-ring, petal structure, retention plate, or the like, suitable for retaining the bone screws once in place and preventing them from backing out. Upon implantation, the bone screws are disposed through the holes 16 and into an underlying bony structure, thereby securing the plate 14 to the bony structure. In the non-limiting exemplary embodiment illustrated, two holes 16 are provided. The plate 14 can include any number of additional holes 16 , 20 that are desirable as a matter of design choice.
The bone plate 10 also includes a pair of carriage assemblies 22 that engage the plurality of screw receiving plate slots 18 . The plurality of slots 18 are each formed through the plate 14 and have an axial length of between about 4 mm and about 8 mm, although other suitable dimensions can be utilized. Each carriage assembly 22 includes a plurality of screw receiving stems 24 that are joined by an elongate bridge member 26 . The stems 24 (a pair of which are illustrated for each carriage assembly 22 in this non-limiting exemplary embodiment) each include a pair of semicircular arcuate members 28 that are separated by opposed notches 30 . The stems 24 are each sized to receive a conventional bone screw or the like, having a locking head or otherwise. Preferably, the stems 24 each include a conventional screw retention mechanism, such as a lip, c-ring, petal structure, retention plate, or the like, suitable for retaining the bone screws once in place and preventing them from backing out. Upon implantation, the bone screws are disposed through the stems 24 and into underlying bony structures, thereby securing the carriage assemblies 22 to the bony structures. In the non-limiting exemplary embodiment illustrated, the stems 24 are disposed through the slots 18 from the bottom of the plate 14 , with the bridge members 26 fitting in recesses manufactured into the bottom of the plate 14 . It will be readily apparent to those of ordinary skill in the art, however, that the stems 24 could be disposed through the slots 18 from the top of the plate 14 , with the bridge members 26 fitting in recesses manufactured into the top of the plate 14 , or the stems 24 could be disposed through the slots 18 from inside the plate 14 , with the bridge members 26 fitting in recesses manufactured into the interior of the plate 14 . Optionally, the screws inserted into the stems 24 are configured to bias the arcuate members 28 outwards such that they impinge on the sides of the slots 18 to a predetermined degree, thereby providing some resistance of the stems 24 to translation within the slots 18 . Further, the bridge members 26 each include a port or screw hole 34 that selectively receives a tool for setting the initial compression provided by the bone plate 10 and/or screws that rigidly secures the bridge members 26 (one or both) to the plate 14 (via an additional plate slot 36 or the like), such as intra-operatively or post-operatively, depending upon the preference of the surgeon employing the device.
The carriage assemblies 22 translate axially with respect to the plate structure 14 via the plurality of screw receiving plate slots 18 , thereby providing the compression mechanism 12 . The plurality of screw receiving plate holes 16 receive and retain a plurality of screws that pass through the plate structure 14 and into a first bony structure disposed beneath the plate structure 14 , thereby securing the plate structure 14 to the first bony structure. The carriage assemblies 22 include a plurality of screw receiving carriage assembly stems 24 and elongate members 26 that join the plurality of screw receiving carriage assembly stems 24 . The plurality of screw receiving carriage assembly stems 24 receive and retain a plurality of screws that pass through the carriage assemblies 22 and into second and third bony structures disposed beneath the carriage assemblies 22 , respectively, thereby securing the carriage assemblies 22 to the second and third bony structures. The carriage assemblies 22 may also include additional holes for receiving screws, as desired. The plurality of screw receiving plate slots 18 translatably receive the plurality of screw receiving carriage assembly stems 24 . The plurality of screw receiving carriage assembly stems 24 are axially translated with respect to the plate structure 14 , in pairs, for example, and in unison, in a collinear manner, and in parallel with respect to one another. The plurality of screw receiving carriage assembly stems 24 prevent rotation of the carriage assembly 22 with respect to the plate structure 14 when the carriage assemblies 22 are translated with respect to the plate structure 14 . The carriage assemblies 22 translate axially with respect to the plate structure 14 , thereby changing the relative position of the plurality of screws associated with the plate structure 14 and the plurality of screws associated with the carriage assemblies 22 , without changing the axial length of the bone plate 10 . The bone plate 10 provides for axial translation of a first bony structure secured to the plate structure 14 with respect to second and third bony structuressecured to the carriage assemblies 22 in a laterally and rotationally constrained manner. Thus, the bone plate 10 provides dynamic compression between the first bony structure secured to the plate structure 14 and the second and third bony structures secured to the carriage assemblies 22 . It will be readily apparent to those of ordinary skill in the art that these concepts can be extended to multiple level embodiments as well. The double level embodiment and these multiple level embodiments are especially useful in spinal applications. It should be noted that pins or other attachment mechanisms can be substituted for screws in all embodiments.
Again, in effect, the bone plate 10 of the present invention provides multiple levels of screws that are secured to bony fragments or structures that are to be joined. These levels of screws are axially translatable with respect to one another, without varying the axial length of the bone plate 10 . This provides contact maintenance and dynamic compression between the bony fragments or structures as resorption occurs, etc., thereby promoting fusion at the arthrodesis site.
As an alternative to the above embodiments, the slots 18 /bridge member 26 of the present invention may be asymmetric and/or the various screw holes 16 , 18 /screws may be asymmetric/independently locking such that asymmetric compression may be applied by the bone plate 10 , for example if a fusion cage and/or bone graft is asymmetric.
Referring now to FIG. 9 , in one exemplary embodiment, the surgical approach used to implant the bone plate 10 ( FIGS. 1-8 ) of the present invention is open. In this open approach, an incision is first made over the target implant site 40 . Next, an implant drill/inserter is placed substantially perpendicular to the implant site and the implant is positioned 42 . The surgeon also ensures that the implant's carriage assembly 22 ( FIGS. 1-8 ) is freely moving. Once the positioning is adequately determined, the implant's locking feature is toggled, such that the carriage assembly 22 is no longer moveable. Next, an awl or other bone piercing instrument is used to mark a drilling location and the locking screw holes or the like are drilled using a drill guide and/or associated instrumentation 44 . Next, the locking screws or the like are engaged with the various bony structures through the implant 46 . Next, the implant's locking toggle is released to allow for dynamic compression 48 . Finally, the implant instrumentation is removed and the implant is left in the patient 50 .
Referring again to FIG. 9 , in another exemplary embodiment, the surgical approach used to implant the bone plate 10 ( FIGS. 1-8 ) of the present invention is percutaneous. In this percutaneous approach, a tube is first inserted substantially perpendicular to the target implant site 52 . Next, an implant drill/inserter is placed substantially perpendicular to the implant site and the implant is positioned 54 . The surgeon also ensures that the implant's carriage assembly 22 ( FIGS. 1-8 ) is freely moving. Once the positioning is adequately determined, the implant's locking feature is toggled, such that the carriage assembly 22 is no longer moveable. Next, an awl or other bone piercing instrument is used to mark a drilling location and the locking screw holes or the like are drilled using a drill guide and/or associated instrumentation 56 . Next, the locking screws or the like are engaged with the various bony structures through the implant 58 . Next, the implant's locking toggle is released to allow for dynamic compression 60 . Finally, the implant instrumentation is removed and the implant is left in the patient 62 .
Optionally, static compression can be applied across the surgical site after the implant is placed by releasing the locking toggle, applying a compressive load, and subsequently locking the locking toggle to maintain the compressive load across the surgical site.
Although the present invention has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present invention, are contemplated thereby, and are intended to be covered by the following claims.
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The present invention provides a bone plate that includes a sliding mechanism that allows for both static and dynamic loading and the associated stabilization or partial or whole immobilization of two or more adjacent bone fragments or vertebral bodies of the spine. This sliding mechanism is designed such that as bone resorbs or the like, the sliding mechanism maintains axial compression in a collinear manner across the bone segments.
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SUMMARY OF THE INVENTION
In a first aspect of the invention there is provided a compound of the formula ##STR2## wherein m is an integer of 1 to 3;
n is an integer of 1 or 2;
q is an integer of 1 to 6;
x is an integer of 2 to 6;
Ph is phenylene
or a pharmaceutically acceptable salt thereof.
In accordance with a second aspect of the invention, there is provided a method for glutamate receptor inhibition which comprises administering to a mammal in need thereof an effective amount of said compound or a pharmaceutically acceptable salt thereof.
In accordance with a third aspect of the invention, there is provided a composition for glutamate receptor inhibition which contains an effective amount of said compound to provide a glutamate receptor inhibition effect, together with at least one pharmaceutically acceptable carrier, dilient or excipient therefor.
DETAILED DESCRIPTION OF THE INVENTION
The presence of chemical substances in spiders which paralyze the nerve of anthropodes such as insects has been elucidated and such substances have been isolated. It has also been confirmed that the nerve paralyzing action of those substances is due to glutamic receptor inhibiting action [N. Kawai, A. Miwa, T. Abe, Brain Res., 247 169-171 (1982); N. Kawai, A. Miwa, M. Saito, M. Yoshioka, Microelectrophoretic Investigations of Mammalian Central Transmitters, Aug. 25, 1983, Camberra, Australia, Lecture Summaries p. 4; N. Kawai, A. Miwa, M. Saito, M. Yoshioka, 29th Congress of the International Union of Physiological Sciences, Aug. 29, 1983, Sydney, Australia, Lecture Summaries p. 89; N. Kawai, 8th Conference en Neurobiologie, Nov. 25, 1983, Gif, France, Lecture Summaries, P. 10; N. Kawai, A. Miwa, T. Abe, Advances in Biological Psychopharmacology, 37 221-227 (1983); T. Abe, N. Kawai, A. Miwa, J. Physiol., 339 243-252 (1983); N. Kawai, A. Miwa, T. Abe, Biomed. Res. 3 353-5 (1982); N. Kawai, S. Yamagishi, M. Saito, K. Furuya, Brain Res., 278 346-349 (1983); and U.S. patent application Ser. No. 59517]. Some of the relevant chemical structures have been reported. For instance, "Proceedings of the Japan Academy", 62 Ser. B, 359 (1986) discloses N 1 -(2,4-dihydroxyphenylacetylasparaginyl)-N 5 -(arginyl-cadaverino-β-alanyl)cadaverine and the like and Chemical Abstracts, 105: 186106d (1986) discloses (2,4-dihydroxyphenylacetylasparaginyl)-polyamine-(arginyl) wherein the polyamine a is --NH(CH 2 ) 3 NH(CH 2 ) 3 NH(CH 2 ) 5 NH--. Nakajima et al., U.S. Pat. No. 4,918,107 (not prior art by virtue of the date of filing subsequent to the priority date of this application) discloses compounds which are cited to show the state of the art.
Contemplated are compounds of the general formula: ##STR3## wherein R is a hydrogen atom or an acyl group, m is an integer of 1 to 3, n is an integer of 1 to 4, p is an integer of 1 to 2, q is an integer of 1 to 6, x is an integer of 2 to 6 and y is an integer of 1 to 3, with the proviso that, when (i) ##STR4## (ii) n is 1, (iii) p is 1, (iv) q is 5 and (v) R is a hydrogen atom, [(CH 2 )x--NH]y is neither (CH 2 ) 2 NH(CH 2 ) 3 NH(CH 2 ) 3 NH nor (CH 2 ) 2 NH(CH 2 ) 4 NH(CH 2 ) 3 NH, or that, when ##STR5## is ##STR6## n is an integer of 2 to 4, p is 2 or [(CH 2 )x--NH]y--R is (CH 2 ) 2 NH 2 , or a salt thereof (referred to as "compound I" hereinafter).
The symbol R in compound I is a hydrogen atom or an acyl group. As the acyl group, mention may be made of, for example, a C 1-6 alkanoyl group (e.g., formyl, acetyl, propionyl, butyryl, isobutyryl, etc.), a C 2-6 alkenoyl group (e.g., acryloyl, crotonoyl, etc.), an aromatic carbonyl group such as C 6-10 arylcarbonyl (e.g., benzoyl, etc.), and a 5- or 6-membered nitrogen- or oxygen-containing heterocyclic carbonyl group (e.g., nicotinoyl, furanoyl, etc.). These acyl groups may be further substituted with for example one or two groups selected from halogen atom (fluorine, chlorine, bromine, iodine, etc.), hydroxyl group, thiol group, carboxyl group and carbamoyl group. Preferred examples of R include H.
The symbol m in compound I is an integer of 1 to 3. That is, 1 to 3 hydroxyl groups may be attached to any of the 2,3,4,5 and 6 positions of the benzene ring and examples thereof are 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2,4-dihydroxyphenyl, 2,5-dihydroxyphenyl, 3,4-dihydroxyphenyl and 2,4,5-trihydroxyphenyl. Preferred examples of m include 1 and 2. Accordingly preferred examples of ##STR7## include groups of ##STR8##
The symbol n in compound I is an integer of 1 to 4. That is, --(CH 2 ) n -- indicates --CH 2 --, --(CH 2 ) 2 --, --(CH 2 ) 3 -- or --(CH 2 ) 4 --. Preferred examples of n include 1 and 2.
The symbol p in compound I is an integer of 1 to 2. That is, ##STR9## indicates ##STR10## which may be abbreviated as --Asn-- or --Gln-- in this specification, respectively.
The symbol q in compound I is an integer of 1 to 6. That is, --(CH 2 )q-- indicates --CH 2 --, --(CH 2 ) 2 --, --(CH 2 ) 3 --, --(CH 2 ) 4 --, --(CH 2 ) 5 -- or --(CH 2 ) 6 --. Preferred examples of q include 5.
The symbols x and y of --[(CH 2 )x--NH]y-- in compound I are an integer of 2 to 6 and an integer of 1 to 3, respectively. That is, --[(CH 2 )x--NH]y-- indicates --(CH 2 )x 1 --NH-- when y is 1, and --(CH 2 )x 2 --NH--(CH 2 )x 3 --NH-- when y is 2, and --(CH 2 )x 4 --NH--(CH 2 )x 5 --NH--(CH 2 )x 6 --NH-- when y is 3, respectively, with the proviso that each of the symbols x 1 to x 6 is independently an integer of 2 to 6 like x. Preferred examples of [(CH 2 )x--NH]y include groups of (CH 2 ) 2 NH and (CH 2 ) 2 NH(CH 2 ) 4 NH(CH 2 ) 3 NH.
Compound I may be a salt with an inorganic acid or organic acid. Examples of salts of inorganic acids are hydrochlorides, sulfates, carbonates and nitrates and examples of salts of organic acids are formates, acetates, propionates, oxalates, succinates, benzoates and p-toluenesulfonates. Preferred examples of the salts include hydrochlorides and acetates. Further, compound I may be a complex salt with a metal such as calcium, zinc, magnesium, cobalt, copper or iron. The amino acid which constitutes compound I may be of the L-form, D-form or DL-form, but the L-form is preferred.
Compound I may be produced, for example, by the following process.
Compound I may be produced by reacting a carboxylic acid [II] of the formula: ##STR11## wherein the symbols are the same as defined above, or a salt or a reactive derivative thereof (referred to as "compound II" hereinafter) with a compound [III] of the formula:
NH.sub.2 (CH.sub.2)q--NHCO--[(CH.sub.2)x--NH]y--R [III]
wherein the symbols are the same as defined above, or a salt thereof (referred to as "compound III" hereinafter) and, if necessary, eliminating a protecting group (Reaction formula 1). ##STR12##
In the above reaction formula 1, the starting compound [II] may be a salt or a reactive derivative thereof and the starting compound [III] may be a salt.
The salt of compound [II] includes inorganic base salts or organic base salts of [II]. Examples of the inorganic base salts of [II] are alkali metal salts, e.g., a sodium salt or a potassium salt and alkaline earth metal salts, e.g., a calcium salt. Examples of the organic base salts of [II] are a trimethylamine salt, triethylamine salt, tert-butyldimethylamine salt, cyclohexylamine salt, dibenzylmethylamine salt, benzyldimethylamine salt, N,N-dimethylaniline salt, pyridine salt or quinoline salt. The reactive derivative of the starting compound [II] means a reactive derivative at the carboxyl group of the compound. The reactive derivative of compound [II] includes acid halides, acid azides, acid anhydrides, mixed acid anhydrides, active amides, active esters and active thioesters. Examples of acid halides of [II] are the acid chloride and the acid bromide. Examples of the mixed acid anhydrides are monoalkylcarbonic acid-mixed acid anhydrides, e.g., mixed acid anhydrides of [II] with monomethylcarbonic acid, monoethylcarbonic acid, monoisopropylcarbonic acid, monoisobutylcarbonic acid, mono-tert-butylcarbonic acid, monobenzylcarbonic acid, mono-(p-nitrobenzyl)carbonic acid or monoallylcarbonic acid, aliphatic carboxylic acid-mixed acid anhydrides, e.g., mixed acid anhydrides of [II] with acetic acid, trichloroacetic acid, cyanoacetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, trifluoroacetic acid, trichloroacetic acid or acetoacetic acid, aromatic carboxylic acid-mixed acid anhydrides, e.g., mixed acid anhydrides of [II] with benzoic acid, p-toluic acid or p-chlorobenzoic acid and organic sulfonic acid-mixed acid anhydrides, e.g., mixed acid anhydrides of [II] with methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid or p-toluenesulfonic acid. Examples of the active amides are amides with nitrogen-containing heterocyclic compounds, e.g., acid amides of [II] with pyrazole, imidazole or benzotriazole and these nitrogen-containing heterocyclic compounds may have a substituent such as a C 1-4 alkyl group (e.g., methyl), a C 1-4 alkoxy group (e.g., methoxy), a halogen atom (e.g., Br,Cl,F), an oxo group, a thioxo group or a C 1-4 alkylthio group (e.g., methylthio). As active esters of [II], there may be used all of those which are used for the synthesis of peptides. Examples thereof include, in addition to organic phosphates, e.g., diethoxy phosphate and diphenoxy phosphate, p-nitrophenyl ester, 2,4-dinitrophenyl ester, cyanomethyl ester, pentachlorophenyl ester, N-hydroxysuccinimide ester, N-hydroxyphthalimide ester, 1-hydroxybenzotriazole ester, 6-chloro-1-hydroxybenzotriazole ester and 1-hydroxy-1H-2-pyridone ester. Examples of the active thioesters of [II] include esters with aromatic heterocyclic thiol compounds, e.g., 2-pyridylthiol ester and 2-benzothiazolylthiol ester and these heterocyclic rings may have a substituent such as an alkyl group, an alkoxy group, a halogen atom or an alkylthio group.
One to three hydroxyl groups on the benzene ring of the starting compound II may be protected with an easily removable protecting group. As examples of the protecting groups, mention may be made of substituted or unsubstituted alkanoyl groups, e.g., acetyl, propionyl and trifluoroacetyl, substituted oxycarbonyl groups, e.g., methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, tert-butoxycarbonyl, phenoxycarbonyl, benzyloxycarbonyl, p-methylbenzyloxycarbonyl or benzhydryloxycarbonyl, a tert-butyl group, aralkyl groups, e.g., benzyl, p-methylbenzyl, p-methoxybenzyl, p-chlorobenzyl, benzhydryl and trityl, and substituted silyl groups, e.g., trimethylsilyl and tert-butyldimethylsilyl. Preferred examples of the protecting group for the hydroxyl group include C 7-10 aralkyl such as benzyl and p-methylbenzyl.
The salt of the starting compound [III] includes salts with inorganic acids or organic acids. Examples of the inorganic acid salts include hydrochloride, hydrobromide, sulfate, nitrate and phosphate. Examples of the organic acid salts include formate, acetate, trifluoroacetate, methanesulfonate and p-toluenesulfonate.
The imino group (including the amino group in the case of R being a hydrogen atom) of the starting compound [III] may be protected with an easily removable protecting group. As examples of the protecting groups for the imino group, mention may be made of substituted or unsubstituted alkanoyl groups, e.g., formyl, acetyl, monochloroacetyl, trichloroacetyl, monoiodoacetyl, 3-oxobutyryl, p-chlorophenylacetyl and p-chlorophenoxyacetyl, aromatic carbonyl groups, e.g., benzoyl and p-tert-butylbenzoyl, substituted oxycarbonyl groups, e.g., methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, p-chlorobenzyloxycarbonyl, p-methylbenzyloxycarbonyl and benzhydryl. Preferred examples of the protecting group for the imino group include substituted oxycarbonyl group such as tert-butoxycarbonyl, benzyloxycarbonyl and p-chlorobenzyloxycarbonyl.
The preparation of salts or reactive derivatives of [II], and of salts of [III], and the introduction of a protecting group into [II] or [III] are easily performed by known processes or processes similar thereto. For the reaction between compound II and compound III, for example, a reactive derivative of starting compound [II] as a substance isolated from a reaction mixture may be reacted with compound III. Alternatively, a reaction mixture as such which contains the reactive derivative of the starting compound [II] which is left unisolated may be reacted with the compound III. A reaction between compound III and compound II, in the case when latter compound is in free acid or in salt form, is effected in the presence of a suitable condensation agent. The condensation agent includes, for example, N,N'-disubstituted carbodiimides such as N,N'-dicyclohexylcarbodiimide, azolides such as N,N'-carbonyldiimidazole, and N,N'-thiocarbonyldiimidazole, dehydrating agents such as N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, phosphorus oxychloride and alkoxyacetylene and 2-halogenopyridinium salts such as 2-chloropyridiniummethyl iodide and 2-fluoropyridiniummethyl iodide. In the case of using these condensation agents, the reaction is considered to proceed through the reactive derivative of [II]. The reaction of compound II and compound III is usually carried out in a solvent. A suitable solvent is selected from those which do not harm the reaction. Examples of the solvent include ethers such as dioxane, tetrahydrofuran, diethyl ether, tert-butyl methyl ether, diisopropyl ether and ethylene glycol dimethyl ether, esters such as ethyl formate, ethyl acetate and butyl acetate, halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, trichlene and 1,2-dichloroethane, hydrocarbons such as n-hexane, benzene and toluene, amides such as formamide, N,N-dimethylformamide and N,N-dimethylacetamide, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, nitriles such as acetonitrile and propionitrile and besides dimethylsulfoxide, sulforan, hexamethylphosphoroamide and water. These may be used alone or as mixed solvents. Preferred examples of the solvent include diethyl ether, toluene, N,N-dimethylformamide, acetonitrile and mixtures thereof. The amount of compound III used is usually 1 to 5 moles, preferably 1 to 3 moles, more preferably 1 to 2 moles per mole of starting compound II.
The reaction is effected at a temperature of -80° to 80° C., preferably -40° to 50° C., most preferably -30° to 30° C. Room temperature (20° to 25° C.) may conveniently be employed. Reaction time varies depending on the nature of the starting compounds II and compound III, the nature of the solvent including the mixing ratio in the case of a mixed solvent, and the reaction temperature, but is usually in the range of from 1 minute to 72 hours, preferably from 15 minutes to 36 hours, more preferably from 2 to 24 hours.
In the case when an acid halide of [II] is used as the compound II, the reaction may be effected in the presence of a deoxidizer for the removal of hydrogen halide generated from the reaction system. As the deoxidizer, mention may be made of, for example, inorganic bases such as sodium carbonate, potassium carbonate, calcium carbonate and sodium bicarbonate, tertiary amines such as triethylamine, tripropylamine, tributylamine, diisopropylethylamine, cyclohexyldimethylamine, pyridine, lutidine, γ-collidine, N,N-dimethylaniline, N-methylpiperidine, N-methyl-pyrrolidine and N-methylmorpholine and alkylene oxides such as propylene oxide and epichlorohydrin.
The objective compound I of the present invention is obtained by allowing compound II to react with compound III as mentioned above and, if necessary, elimination of the protecting group and purification. Elimination of the protecting group for the hydroxyl group is effected by the process as it is which is usually employed in the field of the synthesis of peptides. For example, methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl or phenoxycarbonyl is eliminated by acids, for example, hydrochloric acid or trifluoroacetic acid, benzyloxycarbonyl, p-methylbenzyloxycarbonyl or benzhydryloxycarbonyl is eliminated by catalytic reduction, benzyl, p-methylbenzyl, p-methoxybenzyl, p-chlorobenzyl, benzhydryl or trityl is eliminated by acids, for example, trifluoroacetic acid, or catalytic reduction, and trimethylsilyl or tert-butyldimethylsilyl is eliminated by water alone, or in the presence of acetic acid.
When elimination of a protecting group is carried out, the hydroxyl or/and imino group-protected compound I, which has been isolated from a reaction mixture obtained from the reaction of the compound II and the compound III, may be subjected to the elimination of the protecting group. Alternatively, the reaction mixture may be subjected as it is to elimination of a protecting group. Purification of the hydroxyl, amino or/and imino group-protected compound I or the objective compound I is carried out by the known methods such as extraction, gel filtration, ion-exchange resin column chromatography, silica gel thin-layer chromatography, high-performance liquid chromatography and recrystallization. Compound II and compound III are available by known methods or similar methods thereto.
Furthermore, compound I can also be produced by the following process.
Compound I may be produced by reacting a carboxylic acid [IV] of the formula: ##STR13## wherein the symbols are the same as defined above, or a salt or a reactive derivative thereof (referred to as "compound IV" hereinafter) with a compound [V] of the formula: ##STR14## wherein the symbols are the same as defined above, or a salt thereof (referred to as "compound V" hereinafter) and, if necessary, eliminating a protecting group (Reaction formula 2). ##STR15##
In the above formula 2, the starting compound IV may be a salt or a reactive derivative of [IV]. The salt of the compound [IV] includes inorganic base salts and organic base salts as mentioned for salts of compound [II]. The reactive derivative of compound [IV] includes acid halides, acid azides, acid anhydrides, mixed acid anhydrides, active amides, active esters and active thioesters as mentioned for the reactive derivatives of compound [II]. The salt of the starting compound [V] includes salts with organic acids as mentioned in relation of the compound [III]. The hydroxyl group on the benzene ring of the starting compound IV may be protected and the protective group includes protective groups as mentioned for the protective groups of compound II. Furthermore, the imino group (including the amino group in the case of R being a hydrogen atom) of the starting compound IV may be protected and the protective group includes protective groups as mentioned for the protective groups of compound III.
The preparation of salts or reactive derivatives of [IV] and salts of [V] and the introduction of a protecting group into IV or V are easily performed by known processes or processes similar thereto. The reaction between compound IV and compound V is performed under the same reaction conditions (for example, the presence or absence of condensation agent and kind thereof, the kind of solvent, reaction temperature, reaction time, mole number of starting compounds) and treatment conditions after the reaction (for example, for the elimination of the protecting group and the purification) as mentioned for the reaction between compound II and compound III. Compound [IV] and compound [V] are available by known methods or similar methods thereto.
Compound I has a glutamate receptor inhibiting activity. Therefore, compound I is important for research on isolation, structure elucidation and local analysis of the glutamate receptor. Further, the compound I is useful for the elucidation of the mechanism of memory and cranial nerve diseases with which glutamic acid is associated. Accordingly, the compound [I] or a pharmaceutically acceptable salt thereof can be employed as a medicine for therapy or/and for the prevention of the sequelae of cerebral apoplexy in warm-blooded animals, particularly mammals (e.g. human, mouse, rat, cat, dog, rabbit, etc.).
The compound [I] or salt thereof, when used as a medicine, may be administered orally or parenterally as it is, or in the form of a powder, granule, tablet, capsule, solution, suspension, emulsion, suppository or injection, which is prepared according to the conventional methods using pharmaceutically acceptable excipients, vehicles and diluents. The dose varies according to the animal, the symptom, the compound and the administration route; for example, the dose may be about 0.001 mg to 50 mg preferably 1 mg to 5 mg of the compound of this invention per kg of body weight of a warm-blooded animal described above, in the case of oral administration, and may be administered one to three times per day.
The preparations are produced by per se known processes. The above-mentioned oral preparations, for example tablets, are produced by suitable combination with a binder (e.g. hydroxypropylcellulose, hydroxypropylmethylcellulose, macrogol, etc.), a disintegrator (e.g. starch, calcium carboxylmethylcellulose, etc.), or a lubricant (e.g. magnesium stearate, talc, etc.).
The parenteral preparations, for example injections, are produced by suitable combination with an isotonicity factor (e.g. glucose, D-sorbitol, D-mannitol, sodium chloride, etc.), an antisepetic (e.g. benzyl alcohol, chlorobutanol, methyl p-hydroxybenzoate, probyl p-hydroxybenzoate, etc.), or a buffer (e.g. phosphate buffer, sodium acetate buffer, etc.).
The invention is further illustrated by the following specific examples.
EXAMPLE 1 ##STR16##
18-[N-(N-3,4-Dihydroxyphenylacetyl)asparaginyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate ##STR17##
To 1,4-diaminobutane (84.6 g) cooled with ice, acrylonitrile (50.9 g) was added dropwise. After the addition had been completed, the reaction mixture was stirred for 20 minutes under ice cooling, at 40° C. for one hour and at 100° C. for three hours in this order. The resultant mixture was purified by distillation under reduced pressure to obtain as colorless oil 1-(N-2-cyanoethyl)amino-4-aminobutane (66 g).
Boiling point: 120°-121° C./1.7 mmHg.
Elemental analysis for C 7 H 15 N 3 : Calcd. C: 59.53; H : 10.71; N : 29.76. Found C: 59.61; H : 10.66; N : 29.62. ##STR18##
To a solution of 1-(N-2-cyanoethyl)amino-4-aminobutane (62.8 g) in ethanol (200 ml), a solution of ethyl acrylate (48.2 g) in ethanol (200 ml) was added in small portions. The reaction mixture was refluxed under heating for two hours, and then the solvent was distilled off under reduced pressure to obtain as colorless oil 1-(N-2-cyanoethyl)amino-4-(N-2-ethoxycarbonylethyl)aminobutane (108 g).
IR ν neat (cm -1 ): 1730(C═O), 2260(CN).
Elemental analysis for C 12 H 23 N 3 O 2 : Calcd. C: 59.72; H: 9.61; N: 17.41. Found C: 59.64; H: 9.70; N: 17.36. ##STR19##
To a solution of 1-(N-2-cyanoethyl)amino-4-(N-ethoxycarbonylethyl)aminobutane (60 g) in ethanol (600 ml), Raney-nickel (30 g) was added and reduction was carried out in an autoclave for 3 hours at the reaction temperature of 25° C. and under the pressure in hydrogen stream of 100 kg/cm 2 . After the reaction, the catalyst was removed by filtration and the filtrate was concentrated under reduced pressure to obtain as colorless oil 1-(N-3-aminopropyl)amino-4-(N-2-ethoxycarbonylethyl)aminobutane (60 g).
IR ν neat (cm -1 ): 1725(C═O). NMR δ ppm (CDCl 3 ): 1.26 (t, 3H), 1.2-1.8, (m, 6H), 2.3-3.0 (m, 12H) 4.14 (q, 2H).
Elemental analysis for C 12 H 27 N 3 O 2 : Calcd. C: 58.74; H: 11.09; N: 17.13. Found C: 58.80; H: 10.83; N: 16.88. ##STR20##
To a solution of 1-(N-3-aminopropyl)amino-4-(N-2-ethoxycarbonylethyl)aminobutane (12.2 g) in dichloromethane (200 ml), triethylamine (28 ml) was added, followed by dropwise addition of benzyloxycarbonyl chloride (Cbz-Cl) (29 ml) in small portions under ice cooling and stirring. The reaction mixture was stirred at room temperature for 12 hours, washed by a saturated aqueous sodium hydrogencarbonate solution and 1N hydrochloric acid solution in this order, and dried over anhydrous magnesium sulfate. Colorless oil obtained by distilling the solvent was purified by a silica gel column chromatography. From fractions eluted with dichloromethane-methanol (20: 1), 1-(N-2-ethoxycarbonylethyl-N-benzyloxycarbonyl)amino-4-[N-3-(N-benzyloxycarbonyl)aminopropyl-N-benzyloxycarbonyl]aminobutane (16.0 g) was obtained as colorless oil.
NMR δ ppm (CDCl 3 ): 1.20 (t, 3H), 1.1-1.8, (m, 6H), 2.53(t, 2H), 2.9-3.6 (m, 10H), 4.27 (q, 2H), 5.10(s, 6H), 7.33(m, 15H).
Elemental analysis for C 36 H 45 N 3 O 8 : Calcd. C: 66.75; H: 7.00; N: 6.49. Found C: 66.79; H: 7.12; N: 6.32. ##STR21##
A solution of 1-(N-2-ethoxycarbonylethyl-N-benzyloxycarbonyl)amino-4-[N-3-(N-benzyloxycarbonyl)aminopropyl-N-benzyloxycarbonyl]aminobutane (21 g) in 1N potassium hydroxide-ethanol (68 ml) was stirred at room temperature for 2 hours. Water (100 ml) was added to the reaction mixture, followed by washing twice with diethyl ether (100 ml). The aqueous layer was adjusted to being acidic with 1N hydrochloric acid solution and the resultant was extracted with ethyl acetate. The ethyl acetate layer was washed with water and dried over anhydrous magnesium sulfate. The distillation of ethyl acetate under reduced pressure gave colorless powder of N 4 ,N 9 ,N 13 -tribenzyloxycarbonyl-4,9,13-triazatridecanoic acid (16.3 g).
Elemental analysis for C 34 H 41 N 3 O 8 : Calcd. C: 65.89; H: 6.67; N: 6.78. Found C: 65.77; H: 6.39; N: 6.60. ##STR22##
To a solution of N-(tert-butoxycarbonyl)cadaverine (2.2 g) and N 4 ,N 9 ,N 13 -tribenzyloxycarbonyl-4,9,13-triazatridecanoic acid (6.7 g) in acetonitrile (100 ml), 1-hydroxybenzotriazole (1.46 g) and dicyclohexylcarbodiimide (2.43 g) were added under ice cooling and stirring. The reaction mixture was stirred at room temperature for 12 hours and the precipitated insoluble matter was removed by filtration. The filtrate was concentrated under reduced pressure to give an oily product. The oily product was dissolved in dichloromethane (200 ml), followed by washing with 10% aqueous citric acid solution, a saturated aqueous sodium hydrogencarbonate solution and water in this order. The dichloromethane layer was dried over anhydrous magnesium sulfate. The solvent was distilled under reduced pressure to obtain an oil. The oil was purified by a silica gel column chromatography. From fractions eluted with dichloromethane-methanol (30: 1), 1-(N-benzyloxycarbonyl)amino-18-(N-tert-butoxycarbonyl)amino-N 4 ,N.sup.9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (2.8 g) was obtained as colorless oil.
NMR δ ppm (CDCl 3 ): 1.1-1.9(m, 12H), 1.43(s, 9H), 2.37(t, 2H), 2.9-3.7(m, 14H), 5.10(s, 6H), 7.35(m, 15H).
Elemental analysis for C 44 H 61 N 5 O 9 : Calcd. C: 65.73; H: 7.65; N: 8.71. Found C: 65.54; H: 7.70; N: 8.50. ##STR23##
A solution of 1-(N-benzyloxycarbonyl)amino-18-(N-tert-butoxycarbonyl)amino-N 4 ,N.sup.9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (2.75 g) in trifluoroacetic acid (10 ml) was stirred at room temperature for 10 minutes, followed by addition of dichloromethane (100 ml). The resultant mixture was adjusted to pH 9.0 with a saturated aqueous sodium hydrogencarbonate solution. The organic layer was separated and dried over anhydrous magnesium sulfate. The solvent was distilled to an obtain oil (2.67 g). This oil was dissolved in acetonitrile (50 ml), followed by addition of N-tert-butoxycarbonyl-L-asparagine (1.19 g), 1-hydroxybenzotriazole (0.92 g) and dicyclohexylcarbodiimide (1.06 g) in this order. The reaction mixture was stirred at room temperature for 5 hours. After the reaction had been completed, the precipitated insoluble matter was removed by filtration. The filtrate was concentrated and the resulting oil was dissolved in ethyl acetate (100 ml), followed by washing with 0.5N hydrochloric acid solution, a saturated aqueous sodium hydrogen carbonate solution and water in this order. The ethyl acetate layer was dried over anhydrous magnesium sulfate. The solvent was distilled and the resultant was purified by reprecipitation with ethyl acetatediethyl ether (1: 2) to obtain 18-[N-(N-tert-butoxycarbonyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (1.78 g) as colorless powder.
Elemental analysis for C 48 H 67 N 7 O 11 : Calcd. C: 61.58; H: 7.43; N: 10.48. Found C: 61.43; H: 7.44; N: 10.19. ##STR24##
a) To a solution of 3,4-dibenzyloxyphenylacetic acid (930 mg) in acetonitrile (50 ml), 1-hydroxybenzotriazole (478 mg) and dicyclohexylcarbodiimide (551 mg) were added. The resulting mixture was stirred at room temperature for 2 hours and the precipitate was removed by filtration. The filtrate was concentrated under reduced pressure and to the resultant acetonitrile (20 ml) was added. Insoluble matter was again removed by filtration. The filtrate was used in the following reaction b).
Elemental analysis for C 48 H 67 N 7 O 11 : Calcd. C: 61.58; H: 7.43; N: 10.48. Found C: 61.43; H: 7.44; N: 10.19. ##STR25##
a) To a solution of 3,4-dibenzyloxyphenylacetic acid (930 mg) in acetonitrile (50 ml), 1-hydroxybenzotriazole (478 mg) and dicyclohexylcarbodiimide (551 mg) were added. The resulting mixture was stirred at room temperature for 2 hours and the precipitate was removed by filtration. The filtrate was concentrated under reduced pressure and to the resultant acetonitrile (20 ml) was added. Insoluble matter was again removed by filtration. The filtrate was used in the following reaction b).
b) 1-(N-Benzyloxycarbonyl)amino-18-[N-(N-tert-butoxycarbonyl)asparaginyl]amino-N 4 ,N 9 -benzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (2.04 g) was dissolved in trifluoroacetic acid (5 ml), followed by stirring at room temperature for 30 minutes. To the reaction mixture, toluene (50 ml) was added and distillation was conducted under reduced pressure. To the resultant diethyl ether was added, followed by stirring, to give white precipitate. This precipitate was collected by filtration, dried and dissolved in acetonitrile (30 ml), followed by addition of triethylamine (0.31 ml) under ice cooling and stirring. To the resulting mixture, N,N-dimethylformamide (2 ml) and the acetonitrile solution obtained in the above a) were added. The reaction mixture was stirred at room temperature for 2 hours. The resulting crystalline powder was collected by filtration and dried to obtain 1-(N-benzyloxycarbonyl)amino-18-[N-(N-3,4-dibenzyloxyphenylacetyl)asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (1.1 g) as colorless crystalline powder.
M.p. 150°-151° C.
Elemental analysis for C 65 H 77 N 7 O 12 . 1/2H 2 O: Calcd. C: 67.45; H: 6.79; N: 8.47. Found C: 67.24; H: 6.72; N: 3.45. ##STR26##
To a solution of the protected form, 1-(N-benzyloxycarbonyl)amino-18-[N-(N-3,4-dibenzyloxyphenylacetyl)asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (970 mg) in methanol (68 ml), acetic acid (0.17 ml) and 10% palladium-carbon (300 mg) were added, and catalytic reduction was carried out for 22 hours at room temperature in a hydrogen stream. The catalyst was removed by filtration and the filtrate was concentrated under reduced pressure to obtain a glassy product. This product was purified by column chromatography using Cephadex LH-20. Fractions eluted with 0.1N acetic acid solution in distilled water were collected and lyophilized to obtain colorless glassy 18-[N-(N-3,4-dihydroxyphenylacetyl)asparaginyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate (290 mg).
SIMS: m/z=566[M + +H + ] (C 27 H 47 N 7 O 6 : M=565).
EXAMPLE 2 ##STR27##
18-[N-(N-2,4-Dihydroxyphenylacetyl)glutaminyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate ##STR28##
A solution of 1-(N-benzyloxycarbonyl)amino-18-(N-tert-butoxycarbonyl)amino-N 4 ,N.sup.9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (2.0 g) obtained in Example 1-6) in trifluoroacetic acid (3 ml) was stirred for 30 minutes at room temperature, followed by addition of ethyl acetate (50 ml). The resultant mixture was adjusted to pH 9.3 with a saturated aqueous sodium hydrogencarbonate solution. The ethyl acetate layer was separated and dried over anhydrous magnesium sulfate. The solvent was distilled and the resulting glassy product was dissolved in acetonitrile (50 ml). To the resultant solution, N-tert-butoxycarbonyl-L-glutamine (827 mg), 1-hydroxybenzotriazole (602 mg) and dicyclohexylcarbodiimide (693 mg) in this order. The reaction mixture was stirred for 12 hours at room temperature and the precipitated insoluble matter was removed by filtration. The filtrate was concentrated under reduced pressure and the resultant was dissolved in ethyl acetate (100 ml). The ethyl acetate layer was washed with 0.5N hydrochloric acid solution, a saturated aqueous sodium hydrogencarbonate solution and water in this order, and then dried over anhydrous magnesium sulfate. The solvent was distilled to obtain glassy 18-[N-(N-tert-butoxycarbonyl)glutaminyl]amino-1-(N-benzyloxycarbonyl)amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (1.20 g).
Elemental analysis for C 49 H 69 N 7 O 11 : Calcd. C: 63.14; H: 7.46; N: 10.52. Found C: 62.87; H: 7.41; N: 10.24. ##STR29##
a) To a solution of 2,4-dibenzyloxyphenylacetic acid (495 mg) in acetonitrile (30 ml), 1-hydroxybenzotriazole (254 mg) and dicyclohexylcarbodiimide (293 mg) were added, followed by stirring for 5 hours at room temperature. The resulting precipitate was removed by filtration and the filtrate was concentrated under reduced pressure. To the resultant, acetonitrile (20 ml) was added and insoluble matter was removed by filtration again. The filtrate was used in the following reaction b).
b) 1-(N-Benzyloxycarbonyl)amino-18-[N-(N-tert-butoxycarbonyl)glutaminyl]-amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (1.25 g) was dissolved in trifluoroacetic acid (5 ml), followed by stirring for 30 minutes at room temperature. To the reaction mixture, toluene (50 ml) was added, followed by distillation under reduced pressure. To the resultant, diethyl ether was added and under stirring white powder was precipitated. This powder was collected by filtration, dried and dissolved in acetonitrile (16 ml), followed by addition of triethylamine (0.19 ml) under ice cooling and stirring. The resulting mixture, N,N-dimethylformamide (1.5 ml) and the acetonitrile solution obtained in the above a) were added. The reaction mixture was stirred for 12 hours at room temperature, and the precipitated crystalline powder was collected by filtration and dried to obtain as colorless crystalline powder 1-(N-benzyloxycarbonyl)amino-18-[N-(N-2,4-dibenzyloxyphenylacetyl)glutaminyl]amino-N 4 ,N 9 -benzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (378 mg).
M.p. 144°-147° C.
Elemental analysis for C 66 H 79 N 7 O 12 . H 2 O: Calcd. C: 67.15; H: 6.92; N: 8.31. Found C: 67.21; H: 6.78; N: 8.16. ##STR30##
To a solution of a protected form, 1-(N-benzyloxycarbonyl)amino-18-[N-(N-3,4-dibenzyloxyphenylacetyl)glutaminyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (350 mg) in methanol (24 ml), acetic acid (0.06 ml) and 10% palladium-carbon (30 mg) were added, and catalytic reduction was carried out for 23 hours at room temperature in a hydrogen stream. Thereafter, treatments were effected in the same manner as in Example 1-9) to obtain as colorless powder 18-[N-(N-2,4-dihydroxyphenylacetyl)glutaminyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate (144 mg).
SIMS: m/z=580[M + +H + ] (C 28 H 49 N 7 O 6 : M=579).
EXAMPLE 3 ##STR31##
18-[N-[N-3-(2,4-Dihydroxyphenyl)propionyl]asparaginyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate ##STR32##
a) To a solution of 3-(2,4-dibenzyloxyphenyl)propionic acid (370 mg) in acetonitrile (20 ml), 1-hydroxybenzotriazole (201 mg) and dicyclohexylcarbodiimide (231 mg) were added, followed by stirring for 3 hours at room temperature. The precipitated insoluble matter was removed by filtration and the filtrate was concentrated under reduced pressure. To the resultant, acetonitrile (20 ml) was added and insoluble matter was removed by filtration again. The filtrate was used in the following reaction b).
b) 1-(N-Benzyloxycarbonyl)amino-18-[N-(N-tert-butoxycarbonyl)asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (850 mg) was dissolved in trifluoroacetic acid (5 ml), followed by stirring for 30 minutes at room temperature. To the reaction mixture, toluene (50 ml) was added and distillation was carried out under reduced pressure. To the resultant, diethyl ether was added and stirred to precipitate colorless crystalline powder. This powder was collected by filtration, dried and dissolved in acetonitrile (30 ml), followed by addition of triethylamine (0.14 ml) under ice cooling and stirring. To the resulting mixture, N,N-dimethylformamide (1.5 ml) and the acetonitrile solution obtained in the above a) were added. The reaction mixture was stirred for 22 hours at room temperature, and the precipitated crystalline powder was collected by filtration and dried to obtain 1-(N-benzyloxycarbonyl)amino-18-[N-[N-3-(2,4-dibenzyloxyphenyl)propionyl]asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (340 mg).
M.p. 138°-140° C. ##STR33##
To a solution of a protected form, 1-(N-benzyloxycarbonyl)amino-18-[N-[3-(2,4-dibenzyloxyphenyl)propionyl]asparaginyl]amino-N 4 ,N 9 -dibenzyloxy-4,9,13-triaza-12-oxooctadecane (328 mg) in methanol (50 ml), acetic acid (0.05 ml) and 10% palladium-carbon (50 mg) were added, and catalytic reduction was carried out for 24 hours at room temperature in a hydrogen stream. Thereafter, treatments were effected in the same manner as in Example 1-9) to obtain as colorless powder 18-[N-[N-3-(2,4-dihydroxyphenyl)propionyl]asparaginyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate (93 mg).
SIMS: m/z=580[M + +H + ] (C 28 H 49 N 7 O 6 : M=579).
EXAMPLE 4 ##STR34##
18-[N-(N-2,5-Dihydroxyphenylacetyl)asparaginyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate ##STR35##
a) To a solution of 2,5-dibenzyloxyphenylacetic acid (116 mg) in acetonitrile (7 ml), 1-hydroxybenzotriazole (60 mg) and dicyclohexylcarbodiimide (69 mg) were added, followed by stirring for 4 hours at room temperature. The resulting precipitate was removed by filtration and the filtrate was concentrated under reduced pressure. To the resultant, acetonitrile (10 ml) was added and insoluble matter was removed by filtration again. The filtrate was used in the following reaction b).
b) 1-(N-Benzyloxycarbonyl)amino-18-[N-(N-tert-butoxycarbonyl)asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (313 mg) obtained in Example 1-7) was dissolved in trifluoroacetic acid (1 ml), followed by stirring for 30 minutes at room temperature. To the reaction mixture, toluene (30 ml) was added and distillation was carried out under reduced pressure. To the resultant, diethyl ether was added and after stirring powder was precipitated. The powder was collected by filtration, dried and dissolved in acetonitrile (5 ml), followed by addition of triethylamine (0.05 ml) under ice cooling and stirring. To the resulting mixture, N,N-dimethylformamide (1.5 ml) and then the acetonitrile solution obtained in the above a) were added. The reaction mixture was stirred for 12 hours at room temperature, and the precipitated crystalline powder was collected by filtration and dried to obtain as colorless crystalline powder 1-(N-benzyloxycarbonyl)amino-18-[N-(N-2,5-dibenzyloxyphenylacetyl)asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl4,9,13-triaza-12-oxooctadecane (143 mg).
M.p. 150°-152° C.
Elemental analysis for C 65 H 77 N 7 O 12 . H 2 O: Calcd. C: 66.93; H: 6.83; N: 8.41. Found C: 66.76; H: 6.82; N: 8.07. ##STR36##
To a solution of 1-(N-benzyloxycarbonyl)amino-18-[N-(N-2,5-dibenzyloxyphenylacetyl)asparaginyl]amino-N 4 ,N 9 -dibenzyloxycarbonyl-4,9,13-triaza-12-oxooctadecane (130 mg) in methanol (10 ml), acetic acid (0.02 ml) and 10% palladium-carbon (20 mg) were added, and catalytic reduction was carried out for 23 hours at room temperature in hydrogen stream. Thereafter, treatments were effected in the same manner as in Example 1-9) to obtain 18-[N-(N-2,5-dihydroxyphenylacetyl)asparaginyl]amino-4,9,13-triaza-12-oxo-1-aminooctadecane triacetate (30 mg).
SIMS: m/z=566[M + +H + ] (C 27 H 47 N 7 O 6 : M=565).
EXAMPLE 5 ##STR37##
9-[N-(N-2,4-Dihydroxyphenylacetyl)asparaginyl]amino-4-aza-3-oxo-1-aminononane ##STR38##
To a solution of 1-amino-5-(N-tert-butoxcarbonyl)aminopentane (4.0 g) in N,N-dimethylformamide (20 ml), N-benzyloxycarbonyl-β-alanine (4.42 g), 1-hydroxybenzotriazole (2.68 g) and dicyclohexylcarbodiimide (4.09 g) in this order were added. Thereafter, treatments were effected in the same manner as in Example 1-7) to obtain as colorless powder 9-(N-tert-butoxycarbonyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (3.50 g).
Elemental analysis for C 21 H 33 N 3 O 5 : Calcd. C: 61.89; H: 8.16; N: 10.31. Found C: 61.76; H: 8.30; N: 10.04. ##STR39##
A solution of 9-(N-tert-butoxycarbonyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (3.50 g) in trifluoroacetic acid (20 ml) was stirred for 10 minutes at room temperature. Trifluoroacetic acid was distilled off under reduced pressure and to the resultant, 1N hydrochloric acid-dioxane solution (10 ml) was added. Dioxane was distilled off and to the resultant diethyl ether was added, followed by stirring, to obtain powder. This powder was collected by filtration and dried to obtain 9-amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane monohydrochloride (2.77 g).
Elemental analysis for C 16 H 25 N 3 O 3 . HCl: Calcd. C: 55.88; H: 7.62; N: 12.22. Found C: 55.80; H: 7.77; N: 11.96. ##STR40##
To a solution of 9-amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane monohydrochloride (3.43 g) in N,N-dimethylformamide (30 ml), N-tert-butoxycarbonylasparagine (2.32 g), triethylamine (1.54 ml), 1-hydroxybenzotriazole (1.35 g) and dicyclohexylcarbodiimide (2.17 g) in this order were added under stirring. The reaction mixture was stirred for 12 hours. Thereafter, treatments were effected in the same manner as in Example 1-7) to obtain as colorless powder 9-[N-(N-tert-butoxycarbonyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (5.0 g).
Elemental analysis for C 25 H 39 N 5 O 7 : Calcd. C: 57.56; H: 7.54; N: 13.43. Found C: 57.49; H: 7.70; N: 13.14. ##STR41##
A solution of 9-[N-(N-tert-butoxycarbonyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (4.18 g) in trifluoroacetic acid (20 ml) was stirred for 30 minutes at room temperature. Thereafter, treatments were effected in the same manner as in Example 5-2) to obtain as colorless powder 9-(N-asparaginyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane monohydrochloride (3.51 g).
Elemental analysis for C 20 H 31 N 5 O 5 . HCl: Calcd. C: 52.45; H: 7.04; N: 15.29. Found C: 52.39; H: 6.88; N: 15.03. ##STR42##
To a solution of 9-(N-asparaginyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane monohydrochloride (386 mg) in N,N-dimethylformamide (10 ml), 2,4-dibenzyloxyphenylacetic acid (510 mg), triethylamine (0.16 ml), 1-hydroxybenzotriazole (150 mg) and dicyclohexylcarbodiimide (250 mg) in this order were added under stirring. After the reaction mixture was stirred for 12 hours at room temperature, treatments were effected in the same manner as in Example 5-3) to obtain as colorless crystal 9-[N-(N-2,4-dibenzyloxyphenylacetyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (364 mg).
M.p. 183°-184° C.
Elemental analysis for C 42 H 49 N 5 O 8 : Calcd. C: 67.09; H: 6.57; N: 9.32. Found C: 66.80; H: 6.43; N: 9.08. ##STR43##
To a solution of 9-[N-2,4-dibenzyloxyphenylacetyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (320 mg) in methanol (20 ml), 10% palladium-carbon (50 mg) was added, and catalytic reduction was carried out for 20 hours at room temperature in a hydrogen stream. Thereafter, treatments were effected in the same manner as in Example 1-9) to obtain as colorless powder 9-[N-(N-2,4-dihydroxyphenylacetyl)asparaginyl]amino-4-aza-3-oxo-1-aminononane (160 mg).
Elemental analysis for C 20 H 31 N 5 O 6 . 1/2H 2 O: Calcd. C: 53.80; H: 7.22; N: 15.69. Found C: 53.90; H: 7.50; N: 15.46.
EXAMPLE 6 ##STR44##
9-[N-(N-3,4-Dihydroxyphenylacetyl)asparaginyl]amino-4-aza-3-oxo-1-aminononane ##STR45##
To a solution of 9-(N-asparaginyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (642 mg) obtained in Example 5-4) in N,N-dimethylformamide (10 ml), 3,4-dibenzyloxyphenylacetic acid (435 mg), triethylamine (0.22 ml), 1-hydroxybenzotriazole (189 mg) and dicyclohexylcarbodiimide (383 mg) in this order were added under stirring. After the reaction mixture was stirred for 12 hours at room temperature, treatments were effected in a the same manner as in Example 5-3) to obtain as colorless powder 9-[N-(N-3,4-dibenzyloxyphenylacetyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (600 mg).
Elemental analysis for C 42 H 49 N 5 O 8 : Calcd. C: 67.09; H: 6.57; N: 9.32. Found C: 66.79; H: 6.41; N: 9.12. ##STR46##
To a solution of 9-[N-(N-3,4-dibenzyloxyphenylacetyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (420 mg) in methanol (20 ml), 10% palladium-carbon (56 mg) was added, and catalytic reduction was carried out for 20 hours at room temperature in hydrogen stream. Thereafter, treatments were effected in the same manner as in Example 1-9) to obtain as colorless crystal 9-[N-(N-3,4-dihydroxyphenylacetyl)asparaginyl]amino-4-aza-3-oxo-1-aminononane (176 mg).
M.p. 88°-91° C.
Elemental analysis for C 20 H 31 N 5 O 6 : Calcd. C: 54.91; H: 7.14; N: 16.01. Found C: 55.12; H: 7.23; N: 15.83.
EXAMPLE 7 ##STR47##
9-[N-(N-2,4-Dihydroxyphenylacetyl)glutaminyl]amino-4-aza-3-oxo-1-aminononane monoacetate ##STR48##
To a solution of 9-amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane monohydrochloride (1.10 g) obtained in Example 5-2) in N,N-dimethylformamide (20 ml), N-tert-butoxycarbonylglutamine (1.18 g), triethylamine (0.52 ml), 1-hydroxybenzotriazole (650 mg) and dicyclohexylcarbodiimide (990 mg) in this order were added under stirring. After the reaction mixture was stirred for 12 hours at room temperature, treatments were effected in the same manner as in Example 1 -7) to obtain as colorless powder 9-[N-(N-tert-butoxycarbonyl)glutaminyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (700 mg).
Elemental analysis for C 26 H 41 N 5 O 7 . H 2 O: Calcd. C: 56.40; H: 7.83; N: 12.65. Found C: 56.33; H: 7.70; N: 12.41. ##STR49##
A solution of 9-[N-(N-tert-butoxycarbonyl)glutaminyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (670 mg) in trifluoroacetic acid was stirred for 10 minutes at room temperature. Thereafter, treatments were effected in the same manner as in Example 5-2) to obtain as colorless powder 9-(N-glutaminyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane monohydrochloride (460 mg).
To a solution of this powder in N,N-dimethylformamide (20 ml), 2,4-dibenzyloxyphenylacetic acid (470 mg), triethylamine (0.19 ml), 1-hydroxybenzotriazole (182 mg) and dicyclohexylcarbodiimide (257 mg) in this order were added under stirring. After the reaction mixture was stirred for 12 hours at room temperature, treatments were effected in the same manner as in Example 5 -3) to obtain as colorless crystal 9-[N-(N-2,4-benzyloxyphenylacetyl)glutaminyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (620 mg).
M.p. 217°-219° C.
Elemental analysis for C 43 H 51 N 5 O 8 : Calcd. C: 67.43; H: 6.71; N: 9.15. Found C: 67.60; H: 6.49; N: 8.83. ##STR50##
To a solution of 9-[N-(N-2,4-dibenzyloxyphenylacetyl)glutaminyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (0.57 g) in methanol (10 ml), acetic acid (0.1 ml) and 10% palladium-carbon (50 mg) were added, and catalytic reduction was carried out for 20 hours at room temperature in hydrogen stream. Thereafter, treatments were effected in the same manner as in Example 1-9) to obtain as colorless powder 9-[N-(N-2,4-dihydroxyphenylacetyl)glutaminyl]amino-4-aza-3-oxo-1-aminononane monoacetate (380 mg).
Elemental analysis for C 21 H 33 N 5 O 6 .CH 3 COOH.H 2 O: Calcd. C: 52.16; H: 7.42; N: 13.23. Found C: 52.40; H: 7.29; N: 12.98.
EXAMPLE 8 ##STR51##
9-[N-(N-3-Hydroxyphenylacetyl)asparaginyl]amino-4-aza-3-oxo-1-aminononane ##STR52##
To a solution of 9-(N-asparaginyl)amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (642 mg) obtained in Example 5-4) in N,N-dimethylformamide (10 ml), 3-hydroxyphenylacetic acid (213 mg), triethylamine (0.22 ml), 1-hydroxybenzotriazole (189 mg) and dicyclohexylcarbodiimide (383 mg) in this order were added under stirring. After the reaction mixture was stirred for 12 hours at room temperature, treatments were effected in the same manner as in Example 5-3) to obtain as colorless powder 9-[N-(N-3-hydroxyphenylacetyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (530 mg).
Elemental analysis for C 28 H 37 N 7 O 5 : Calcd. C: 60.52; H: 6.71; N: 12.61. Found C: 60.33; H: 6.89; N: 12.48. ##STR53##
To a solution of 9-[N-(N-3-hydroxyphenylacetyl)asparaginyl]amino-1-(N-benzyloxycarbonyl)amino-4-aza-3-oxononane (470 mg) in methanol (10 ml), 10% palladium-carbon (50 mg) was added, and catalytic reduction was carried out at room temperature in hydrogen stream. The reaction mixture was treated in the same manner as in Example 1-9) to obtain as colorless crystal 9-[N-(N-3-hydroxyphenylacetyl)asparaginyl]amino-4-aza-3-oxononane (310 mg).
M.p. 114°-115° C.
Elemental analysis for C 20 H 31 N 5 O 5 : Calcd. C: 56.99; H: 7.14; N: 16.62. Found C: 56.74; H: 7.03; N: 16.31.
EXAMPLE 9
In the same manner as in Example 8, compounds of Table-1 were obtained.
TABLE 1______________________________________ ##STR54## Elemental analysis Calcd.m.p. molecular (Found)R (°C.) formula C H N______________________________________2-OH 82-85 C.sub.20 H.sub.31 N.sub.5 O.sub.5 56.99 7.14 16.62 (56.90 6.88 16.39)4-OH 180-183 C.sub.20 H.sub.31 N.sub.5 O.sub.5 56.99 7.14 16.62 (57.20 7.38 16.40)2,5-di-OH crystalline C.sub.20 H.sub.31 N.sub.5 O.sub.6 54.91 7.14 16.01 powder (54.68 7.00 15.73)______________________________________
REFERENCE EXAMPLE 1 ##STR55##
(i) 2,4-Dihydroxybenzaldehyde (14.5 g) was dissolved in ethanol (60 ml) and then thereto were added benzyl chloride (30 ml) and sodium carbonate (1.7 g), followed by reflux under heating for 5 hours. Insoluble matters were removed by filtration. The filtrate was allowed to stand for cooling and then the produced solid was collected by filtration and recrystallized from ethanol to obtain 2,4-dibenzyloxybenzaldehyde (20 g, yield 60%). Melting point: 89°-90° C.
(ii) 2,4-Dibenzyloxybenzaldehyde (20 g) was dissolved in methanol (700 ml) and then thereto was added sodium borohydride (3.6 g) and this was left to stand at room temperature (20° C.) for 1.5 hours. To the reaction mixture was added water (1.5 l) and the resulting precipitate was collected by filtration and recrystallized from ethanol to obtain 2,4-dibenzyloxybenzyl alcohol (19.8 g, yield 98%). Melting point; 84°-85° C.
(iii) 2,4-Dibenzyloxybenzyl alcohol (19.8 g) was dissolved in anhydrous benzene (150 ml) and then thereto was added thionyl chloride (40 g), followed by reflux under heating for 1 hour. This was concentrated to dryness under reduced pressure to obtain crude 2,4-dibenzyloxybenzyl chloride. This product was used for the subsequent reaction without purification.
(iv) The above obtained crude 2,4-dibenzyloxybenzyl chloride was dissolved in dimethyl sulfoxide (150 ml) and then thereto was added sodium cyanide (4 g), followed by stirring for 2 hours at room temperature (20° C.). The reaction mixture was added to water (1 l) and extracted with dichloromethane (1 l). The dichloromethane extract was concentrated under reduced pressure and the residue was purified by a silica gel column (inner diameter: 10 cm, length 50 cm; developer: dichloromethane-n-hexane 1: 1 (v/v) mixed solution) and furthermore, was recrystallized from diethyl ether-n-hexane 2: 1 (v/v) mixed solution to obtain 2,4-dibenzyloxyphenylacetonitrile (14.3 g, yield 70% from 2,4-dibenzyloxybenzyl alcohol). Melting point: 99°-100° C.
(v) 2,4-Dibenzyloxyphenylacetonitrile (14.3 g) was dissolved in ethanol (250 ml) and then, thereto was added an aqueous potassium hydroxide solution (prepared by dissolving 32 g of potassium hydroxide in 80 ml of water), followed by reflux under heating for 15 hours. The reaction mixture was concentrated under reduced pressure and then dissolved in water (100 ml). The solution was made acidic with concentrated hydrochloric acid and extracted with dichloromethane. The dichloromethane extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. Thereafter, the residue was subjected to separation and purification by a silica gel column (inner diameter: 10 cm, length: 50 cm; developer: dichloromethane-ethyl acetate 4: 1 (v/v) mixed solution). Thus separated and purified product was recrystallized from benzene to obtain 2,4-dibenzyloxyphenylacetic acid (14.4 g, yield 95%). Melting point: 139° C.
REFERENCE EXAMPLE 2 ##STR56##
(i) To a solution of 2,4-dibenzyloxybenzaldehyde (702 mg) in toluene (30 ml), ethoxycarbonylmethylenetriphenylphosphoran (1.0 g) was added, followed by reflux under heating for 2.5 hours. After the reaction mixture was allowed to stand for cooling, the solvent was distilled off and the residue was purified by a silica gel column chromatography. From the fraction eluted with dichloromethane was obtained ethyl 3-(2,4-dibenzyloxyphenyl)-2-propenoate (794 mg) as an oily product.
Elemental analysis for C 25 H 24 O 4 : Calcd. C: 77.30; H: 6.23 Found C: 77.28; H: 6.30
NMR δ ppm(CDCl 3 ): 1.27(t, 3H), 4.20(q, 2H), 5.00(s, 2H), 5.08(s, 2H), 6.46-6.63(m, 3H), 7.10-7.50(m, 5H), 7.67-7.80(d, 1H), 7.86-8.05(d, 1H)
(ii) Sodium borohydride (10 mg) was added to an ethanolic solution (100 ml) of nickel chloride (100 mg), followed by stirring for 5 minutes. Then, thereto was added ethyl 3-(2,4-dihydroxyphenyl)-2-propenoate (780 mg), followed by addition of sodium borohydride (100 mg) in small portions under ice cooling and stirring. After the reaction terminated, 5N hydrochloric acid solution (0.2 ml) was added and the precipitated insoluble matter was removed by filtration. Ethanol was distilled off and the resultant was dissolved in dichloromethane. The dichloromethane solution was washed with water and dried over anhydrous sodium sulfate. Dichloromethane was distilled off to obtain ethyl 3-(2,4-dibenzyloxyphenyl)propionate (750 mg) as colorless oil.
Elemental analysis for C 25 H 26 O 4 :
Calcd. C: 76.90; H: 6.71.
Found C: 76.78; H: 6.84.
NMR δ ppm(CDCl 3 ): 1.18(t, 3H), 2.45-3.05(m, 4H), 4.07(q, 2H), 4.97(s, 2H), 5.01(s, 2H), 6.38-7.50(m, 13H)
(iii) To a solution of ethyl 3-(2,4-dibenzyloxyphenyl)propionate (12.0 g) in ethanol (300 ml), sodium hydroxide (10.3 g) was added, followed by stirring at room temperature for 6 hours. The reaction mixture was adjusted to pH 4.0 with addition of 5N hydrochloric acid solution. Ethanol was distilled off and to the residue was added water. The precipitated crystal was collected by filtration, washed with water and dried to obtain as colorless crystal 3-(2,4-dibenzyloxyphenyl)propionic acid (9.4 g).
M.p. 125°-127.5° C.
Elemental analysis for C 23 H 22 O 4 : Calcd. C: 76.22; H: 6.12. Found C: 76.37; H: 6.30.
NMR δ ppm(CDCl 3 ): 2.47-3.03(m, 4H), 4.97(s, 2H), 5.02(s, 2H), 6.40-7.53(m, 13H).
REFERENCE EXAMPLE 3
Boc--NH(CH 2 ) 5 NH 2
5-(N-tert-Butoxycarbonyl)amino-1-aminopentane (N-tert-butoxycarbonylcadaverine) ##STR57##
i) To a solution of 5-amino-1-pentanol (10 g) in dioxane (50 ml), tert-butyl 4,6-dimethylpyrimidin-2-ylthiolcarbonate (Boc-SDP)(23.31 g) was added, followed by stirring at room temperature for 12 hours. The solvent was distilled off and the resultant was dissolved in ethyl acetate (300 ml). The ethyl acetate solution was washed with 1N hydrochloric acid solution and dried over anhydrous sodium sulfate. The solvent was distilled off to obtain as colorless oil 5-(N-tert-butoxycarbonyl)amino-1-pentanol (14.3 g).
Elemental analysis for C 10 H 21 NO 3 : Calcd. C: 66.90; H: 8.42; N: 5.57. Found C: 66.77; H: 8.19; N: 5.36.
ii) To a solution of 5-(N-tert-butoxycarbonyl)amino-1-pentanol (21.3 g) in anhydrous tetrahydrofuran (300 ml), triphenylphosphine (54.9 g), phthalimide (30.8 g) and dimethylazodiformate (30.6 g) were added under ice cooling and stirring. The reaction mixture was stirred at room temperature for 3 hours. The solvent was distilled off under reduced pressure and the resultant was extracted with n-hexane-ethyl acetate (2: 1). The organic layer was concentrated under reduced pressure to obtain colorless oil. The oil was purified by a silica gel column chromatography. From fractions eluted with n-hexane-ethyl acetate (2: 1), N-[5-(N-tert-butoxycarbonyl)amino]pentylphthalimide (22.5 g) was obtained.
M.p. 81°-83° C.
Elemental analysis for C 18 H 24 N 2 O 4 : Calcd. C: 65.04; H: 7.28; N: 8.43. Found C: 64.87; H: 7.02; N: 8.70.
iii) To a solution of N-[5-(N-tert-butoxycarbonyl)amino]pentylphthalimide (21.5 g) in methanol (500 ml), hydrazine hydrate (20 ml) was added, followed by stirring for 4 hours under heating at 80° C. The precipitated crystal was removed by filtration and the filtrate was concentrated under reduced pressure to obtain as colorless oil 5-(N-tert-butoxycarbonyl)amino-1-aminopentane (11.9 g).
Elemental analysis for C 10 H 22 N 2 O 2 : Calcd. C: 59.37; H: 10.96; N: 13.85. Found C: 59.10; H: 10.71; N: 13.79.
REFERENCE EXAMPLE 4 ##STR58##
i) To a solution of 3,4-dihydroxyphenylacetic acid (10 g) in N,N-dimethylformamide (50 ml), potassium carbonate (74 g) and benzyl bromide (37 g) were added, followed by stirring at 40° C. for 6 hours. The solvent was distilled off and the resultant was extracted with dichloromethane. The dichloromethane extract was washed with water and then dried over anhydrous sodium sulfate. The solvent was distilled off to obtain as colorless crystal benzyl 3,4-dibenzyloxy phenylacetate (16.0 g).
M.p. 71.5°-72.5° C.
Elemental analysis for C 29 H 26 O 4 : Calcd. C: 79.43; H: 5.98. Found C: 79.42; H: 5.86.
ii) Potassium hydroxide (6.2 g) was added to a solution of benzyl 3,4-dibenzyloxyphenylacetate (16.0 g) in methanol (200 ml), followed by stirring at room temperature for 6 hours. The reaction mixture was adjusted to pH 4.0 with 5N hydrochloric acid solution. The solvent was distilled off and to the residue was added water. The precipitated crystal was collected by filtration, washed with water and dried to obtain as colorless crystal 3,4-dibenzyloxyphenylacetic acid (10.0 g).
M.p. 112°-113° C. Elemental analysis for C 22 H 20 O 4 : Calcd. C: 75.84; H: 5.79. Found C: 75.79; H: 5.80.
REFERENCE EXAMPLE 5 ##STR59##
i) In the same manner as in Reference example 4-i), benzyl 2,5-dibenzyloxyphenylacetate was obtained from 2,5-dihydroxyphenylacetic acid.
M.p. 73°-74.5° C.
Elemental analysis for C 29 H 26 O 4 : Calcd. C: 79.43; H: 5.98. Found C: 79.50; H: 5.77.
ii) In the same manner as in Reference example 4-ii), benzyl 2,5-dibenzyloxyphenylacetate was hydrolized to obtain 2,5-dibenzyloxyphenylacetic acid.
M.p. 95.5°-100° C.
Elemental analysis for C 22 H 20 O 4 : Calcd. C: 75.84; H: 5.79. Found C: 75.81; H: 5.63.
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A compound is provided which has the formula ##STR1## wherein m is an integer of 1 to 3;
n is an integer of 1 or 2;
p is an integer of 1 or 2;
q is an integer of 1 to 6;
x is an integer of 2 to 6;
Ph is phenylene
or a pharmceutically acceptable salt thereof. Also provided is a method for glutamate receptor inhibition which comprises administering to a mammal in need thereof an effective amount of said compound or a pharmaceutically acceptable salt thereof. Compositions for glutamate receptor inhibition are provided which contain an effective amount of said compound to provide a glutamate receptor inhibition effect, together with at least one pharmaceutically acceptable carrier, dilient or excipient therefor.
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BACKGROUND OF THE INVENTION
The present invention relates to a current controlling device for an electromagnetic winding. In particular, it relates to a current controlling device for controlling a starting current and a holding current supplied to an electromagnetic winding of a solenoid valve and the like.
To Drive an electromagnetic appliance such as a solenoid valve, an electromagnetic nozzle or an electromagnetic relay, in general, a large starting current initially is supplied to an electromagnetic winding thereof, and then, the current is reduced to a controllable holding current lower than the starting current in order to hold the condition after start up.
FIG. 1 shows a prior controlling device to perform the above current control, and FIG. 2 shows a characteristic curve of current flowing through an electromagnetic winding of the circuit in FIG. 1. This current controlling device has been shown in the U.S. Pat. No. 4,345,296.
In those figures, when a driving signal 1 is not supplied, an input terminal 2 has zero potential. Consequently, transistors 3 and 5 are in off state, and a transistor 4 is in on state. Therefore, the current does not flow through an electromagnetic winding 6. A comparator 7 at its (+)input terminal is grounded through resistors 8 and 9, and a (-)input terminal thereof is supplied with a source voltage by means of an on state of a transistor 10. Therefore, the output level of the comparator 7 is in L level (low level), and a transistor 11 is cut off. If the driving signal 1 appears at the input terminal 2 at the time point t 0 of FIG. 2, the potential of the input terminal 2 becomes high, thus the transistors 3, 5 are conductive, and the transistors 4, 10 are cut off. When the transistor 10 is cutt off, the (-)input terminal of the comparator 7 is supplied with the source voltage divided by resistors 12 and 13. When the transistor 5 is conductive, a starting current IA flows through the electromagnetic winding 6 and rises gradually, thereby causing the voltage drop across the resistor 9 to increase. If the starting current IA rises to the maximum value IA max , the voltage applied to the (+)input terminal of the comparator 7 exceeds the voltage applied to the (-)input terminal thereof, and the output level of the comparator 7 becomes H level (high level), thereby causing the transistor 11 to be conductive. Therefore, a zener diode 14 is inserted in parallel into the series connection of the base-emitter circuit of the transistor 5 and the resistor 9. Consequently, when the zener voltage is applied to said series connection, the current which flows through the electromagnetic winding 6 decreases from IA max to a lower holding current IH. If the driving signal 1 comes to an end, the potential at the input terminal 2 becomes zero, and the circuit is returned to the initial condition.
However, the prior controlling circuit has disadvantages as described below.
According to the prior art, since the starting current IA rises freely to the maximum value IA max thereof, the heat loss in the electromagnetic winding increases, and undesirable heating may be produced. That is to say, in order to reduce the heat loss, it is preferable that the maximum value IA max of the starting current be a lower value. In the prior art, however, the reduction of the maximum value IA max is accompanied by narrowing of the starting period T, and results in obstruction of the driving of, for example, a solenoid valve to be controlled. Consequently, in the prior art, since the reduction of the maximum value IA max is difficult, heat loss is increased because of the large starting current.
Also, in the prior art, the large current flows until the starting current attains the maximum value IA max even if the solenoid value has been completely opened before the end of the starting period T, causing heat loss to increase still more.
Further, in the prior art, since the reference voltage of the comparator 7 is obtained by dividing the source voltage by the resistors 12 and 13, the reference voltage is easily varied with the fluctuation of the source voltage. Therefore, the characteristics of the current flowing through the electromagnetic winding vary, and the stable control of the solenoid valve may be obstructed.
SUMMARY OF THE INVENTION
It is an object, therefore, of the present invention to overcome the disadvantages and limitations of prior current controlling devices by providing a new and improved current controlling device.
Another object of the present invention is to provide current controlling device which can reduce a heat loss in an electromagnetic winding.
Still another object of the present invention is to provide a current controlling device which can control an electromagnetic appliance using an electromagnetic winding stably in spite of fluctuation of a source voltage.
The above and other objects are attained by a current controlling device comprising an input circuit for receiving a driving signal; reference voltage supply means for supplying a first reference voltage or a second reference voltage lower than the first reference voltage, said first and second reference voltage being controlled to constant voltages, respectively, and said second reference voltage being supplied until the end of the driving signal and after a predetermined time from the input of the driving signal, instead of said first reference voltage; a detecting resistor for detecting the current flowing through the electromagnetic winding; and current control means for supplying the electromagnetic winding with the starting current and the holding current, the starting current being regulated to a predetermined value as it rises on the basis of the detected voltage of said detecting resistor and said first reference voltage, and the holding current being regulated to another predetermined value lower than said predetermined value on the basis of said detected voltage and said second reference voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and attendant advantages of the present invention will be appreciated as the same become better understood by means of the following description and accompanying drawings wherein;
FIG. 1 is a circuit diagram of a current controlling device in the prior art,
FIG. 2 is a characteristic curve of current flowing through an electromagnetic winding of the circuit of FIG. 1,
FIG. 3 is a circuit diagram of a current controlling device according to the present invention,
FIG. 4 is an operational time chart of the circuit of FIG. 3 according to the present invention.
FIG. 5 shows starting characteristic curves given by the constant current control of the starting current shown in FIG. 4 and the non-control of the starting current shown in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows a current controlling device for driving an electromagnetic winding 20 of a solenoid valve. Even when the electromagnetic winding 20 is applied to an electromagnetic nozzle or an electromagnetic relay, the device in FIG. 3 can be used.
The current controlling device comprises an input circuit 30 for receiving a driving signal VI, current control means 40 for controlling the current flowing through the electromagnetic winding 20, reference voltage supply means 50 for supplying the current control means 40 with a first reference voltage V R1 and a second reference voltage V R2 lower than the first reference voltage V R1 , and a detecting resistor 60 for detecting the current which flows through the electromagnetic winding 20.
An input terminal IN of the input circuit 30 is connected to a photo diode 302 of the photo coupler 301. A photo transistor 303 of the photo coupler 301 at its emitter is grounded, and its collector is connected to a base of switching transistor 304. The base of the transistor 304 is also connected through a resistor 305 to the power source line. An emitter of the transistor 304 is grounded, and its collector is introduced in the current control means 40. The transistor 304 is conductive when the driving signal VI is not supplied, because the photo transistor 303 is cut off. On the other hand, when the driving signal VI is supplied, the transistor 304 is cut off because the photo transistor 303 is conductive.
The collector of the switching transistor 304 is connected through a resistor 402 to an output side of a comparison amplifier 401 of the current control means 40. The junction point between the collector of the transistor 304 and the resistor 402 is connected to a base of a forward-stage driving transistor 403. The transistor 403 constitutes a driving circuit of the electromagnetic winding 20 together with a current limiting circuit 404 and a rearward-stage driving transistor 405. The collector of the forward-stage driving transistor 403 is connected to the current limiting circuit 404, and its emitter is connected to the base of the rearward-stage driving transistor 405. The current limiting circuit 404 which comprises two transistors 406, 407 and two resistors 408, 409 limit the collector current of the transistor 403. By means of this limiting, extreme saturation of the rearward-stage driving transistor 405 is prevented. A collector of the transistor 405 is connected to one end of the electromagnetic winding 20, and its emitter is connected to one end of the detecting resistor 60. The other end of the electromagnetic winding 20 is connected to the power source line. The other end of the detecting resistor 60 is grounded. The current I flowing through the electromagnetic winding 20 is supplied by the rearward-stage driving transistor 405. The base current of the transistor 405 is the emitter current of the forward-stage driving transistor 403. The base current of the transistor 403 is supplied from the comparison amplifier 401.
The comparison amplifier 401 constitutes a comparison amplifier circuit together with a resistor 402, a capacitor 410, a zener diode 411 and a resistor 412. Preferably, the comparison amplifier 401 is composed of an operational amplifier of which input stage transistors are PNP type (for example, μPC1251C of Nippon Electric Co., Ltd.). According to such an operational amplifier, the lowest value of the input voltage range is 0 (V) since there is no retained voltage in the input stage. While, according to an operational amplifier which has NPN transistors in its input stage, the lowest value of the input voltage range is higher than 0 (V) because of residual voltage in the input stage. Therefore, if the comparison amplifier 401 is composed of the preferable operational amplifier, the relative resistance value of the detecting resistor 60 to the electromagnetic winding 20 can be decreased, for example, to 1/5 or less as compared with the operational amplifier having the NPN transistors in the input stage, since it is not necessary that the voltage drop across the detecting resistor 60 be enlarged. Therefore, the power consumption of the detecting resistor 60 and the heat loss thereof can be reduced. Thus, not only the power loss of the detecting resistor 60 but also the consideration for a heat resisting property will be decreased.
The comparison amplifier 401 at its (-)input terminal is connected through the resistor 412 to the point between the transistor 405 and the resistor 60. Therefore, the (-)input terminal of the amplifier 401 is supplied with the detected voltage V s corresponding to the current I flowing through the electromagnetic winding 20. A feedback circuit including the parallel connection of the capacitor 410 and the zener diode 411 is inserted between the (-)input terminal and the output terminal of the comparison amplifier 401. The capacitor 410 is for the phase compensation of the amplifier 401. The zener diode 411 functions as the voltage limiter of the amplifier 401. The zener diode 411 suppresses the over-bias to the forward-stage driving transistor 403 at the starting operation, and reduces the overshooting of the current I. The (+)input terminal of the amplifier 401 is connected to the reference voltage supply means 50, and receives the first reference voltage V R1 or the second reference voltage V R2 from the supply means 50. The output of the amplifier 401 is applied to the base of the transistor 403 so that the difference between the first reference voltage V R1 or the second reference voltage V R2 and the detected voltage V S becomes zero.
The (+)input terminal of the comparison amplifier 401 is connected to a resistor 501 of the reference voltage supply means 50 by means of a slider, and also connected to another resistor 502. The first reference voltage V R1 is supplied by the resistor 501. The second reference voltage V R2 is supplied by the parallel insertion of the resistor 502 to the resistor 501. The resistor 501 is connected in parallel to a zener diode 503. The anode of the zener diode 503 is grounded, and the cathode thereof is connected through a constant-current FET 504 to the power source line. The other resistor 502 with its one end connected to the (+)input terminal of the amplifier 401 has the other end grounded through a collector-emitter circuit of a switching transistor 505. By means of such connection between the resistors 501, 502 and the zener diode 503, a constant voltage is applied to the resistors 501, 502. Therefore, the first reference voltage V R1 and the second reference voltage V R2 do not fluctuate even when the source voltage fluctuates.
The switching transistor 505 constitutes a switching means together with a resistor 506, a comparator 507, resistors 508, 509 and a capacitor 510. This switching means inserts the resistor 502 in parallel with the resistor 501, or separates the resistor 502 from the resistor 501. The resistors 508, 509 and the capacitor 510 constitute a time constant circuit. The base of the transistor 505 is connected through the resistor 506 to the output terminal of the comparator 507. The (+)input terminal of the comparator 507 is connected through the resistor 508 to the base of the forward-stage driving transistor 403, and also grounded through the parallel connection of the resistor 509 and the capacitor 510. Consequently, the (+)input terminal of the comparator 507 is supplied with an input voltage V C rising in accordance with the time constant determined by the resistors 508, 509 and the capacitor 510, when the transistor 304 is cut off. The (-)input terminal of the comparator 507 is connected to the (+)input terminal of the comparison amplifier 401. Therefore, the (-)input terminal of the comparator 507 is supplied with the first reference voltage V R1 or the second reference voltage V R2 . The comparator 507 makes the transistor 505 conduct when the input voltage V C attains to the first reference voltage V R1 , and makes the transistor 505 cut off when the input voltage V C becomes the second reference voltage V R2 or less. The resistor 502 is inserted in parallel with the resistor 501 when the transistor 505 is conductive. The resistor 502 is separated from the resistor 501 when the transistor 505 is cut off.
FIG. 4 shows the operational time chart of the device of FIG. 3. The driving signal V I , the current I, the detected voltage V S , the input voltage V C , the first reference voltage V R1 and the second reference voltage V R2 are shown in FIG. 4.
If the driving signal V I is not applied to the input terminal NI, the photo transistor 303 is in an off state, and the switching transistor 304 is conductive since the transistor 304 is supplied with base current through the resistor 305. Therefore, the base potential of the forward-stage driving transistor 403 is approximately 0 (V). Therefore, the current I which flows through the electromagnetic winding 20 is zero because the transistors 403 and 405 are not driven. On the other hand, since the input voltage V C applied to the (+)input terminal of the comparator 507 is approximately 0 (V), the switching transistor 505 is in off state. Consequently, the (+)input terminal of the amplifier 401 is supplied with the first reference voltage V R1 by means of the resistor 501. The (-)input voltage of the amplifier 401 is zero because the current I is zero. Therefore, the output voltage of the amplifier 401 is saturated in the direction so that the amplifier 401 provides the current I with the electromagnetic winding 20. Since this saturation voltage is limited by the zener diode 411, the amplifier 401 is prevented from oversupplying the base current to the forward-stage driving transistor 403 when the transistor 304 is cut off, and the overshooting of the current I is suppressed.
If the driving signal V I is supplied to the input terminal IN, the photo transistor 303 is conductive. Therefore, the base potential of the switching transistor 304 becomes approximately zero, and the transistor 304 is cut off. Consequently, the base of the forward-state driving transistor 403 is supplied with the output of the amplifier 401, and then, the rearward-stage driving transistor 405 is driven. Accordingly, the starting current I a begins to flow through the electromagnetic winding 20. As shown in FIG. 4, the starting current I a rises freely until the detected voltage V S (or the voltage drop of the detecting resistor 60) rises to the first reference voltage V R1 , and then, the starting current I a is controlled so that the detected voltage V S corresponds to the first reference voltage V R1 . Consequently, the starting current I a is controlled to a constant value as shown in FIG. 4. This constant value is set to a current value lower than the maximum value IA max in FIG. 2.
When the switching transistor 304 is cut off, the input voltage V C applied to the (+)input terminal of the comparator 507 rises according to the time constant determined by the resistors 508, 509 and the capacitor 510. When the input voltage V C attains to the first reference voltage V R1 , the output of the comparator 507 inverts to the H level. Thus, the switching transistor 505 is conductive, and the resistor 502 is inserted in parallel with the resistor 501. Consequently, the second reference voltage V R2 , which is lower than the first reference voltage V R1 , is supplied to the amplifier 401 and the comparator 507.
The amplifier 401, therefore, reduces the mean output voltage so that the detected voltage V S corresponds to the second reference voltage V R2 . Thus, the current I is reduced to the holding current I b , which is lower than the starting current I a , as shown in FIG. 4.
The input voltage V C of the comparator 507 decreases in accordance with the reduction of the mean output voltage of the amplifier 401. However, since the reference voltage applied to the (-)input terminal of the comparator 507 changes into the second reference voltage V R2 , which is lower than the first reference voltage V R1 , the output level of the comparator 507 is not inverted. Therefore, the transistor 505 continues in the on state.
If the driving signal V I ends, the switching transistor 304 becomes conductive again. Therefore, the driving transistor 403 and 405 are cut off, and the current I is zero. Since the input voltage V C becomes less than the second reference voltage V R2 because of the on state of the transistor 304, the output of the comparator 507 inverts to the L level. Thus, the switching transistor 505 is cut off, and the first reference voltage V R1 is supplied again to the amplifier 401 and the comparator 507.
FIG. 5 shows starting characteristic curves given by the constant current control of the starting current according to the present invention shown in FIG. 4 and the non-control of the starting current shown in FIG. 2. In FIG. 5, the curve (A) shows the variation of the starting current given by the constant current control, and the curve (A') of the broken line shows that given by the non-control. The curve (B) shows the variation of the magnetic flux of electromagnetic winding given by the constant current control, and the curve (B') shows that given by the non-control. The curve (C) shows the variation of the generated force given by the constant current control, and the (C') shows that given by the non-control. The curve (D) shows the movement of the valve given by the constant current control, and the curve (D') shows that given by the non-control. As apparent from FIG. 5, even when the starting current is made constant as it rises, there is scarcely any difference with respect to the generated force and the valve movement between the constant current control and the non-control.
As described in detail, the current controlling device according to the present invention can reduce the heat loss in the electromagnetic winding, since the starting current is regulated to a constant value lower than the maximum value IA max as in the case where the starting current rises freely. Further, the present current controlling device can control an electromagnetic appliance stably even if the source voltage fluctuates, since the first and second reference voltages are controlled to constant voltages, respectively.
From the foregoing it will now be apparent that a new and improved current controlling device has been found. It should be understood of course that the embodiment disclosed is merely illustrative and is not intended limit to the scope of the invention. Reference should be made to the appended claims, therefore, rather than the specification as indicating the scope of the invention.
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A current controlling device comprises an input circuit for receiving a driving signal, means for supplying a first reference voltage or a second reference voltage lower than the first reference voltage, a detecting resistor for detecting current flowing through an electromagnetic winding, and means for supplying the electromagnetic winding with a starting current and a holding current. The starting current initially rises then is maintained at a constant value based upon the detected voltage of the detecting resistor and the first reference voltage. The second reference voltage is supplied in place of the first reference voltage after a predetermined period of time and continues to be supplied until the driving signal ends. The holding current is maintained at a constant value lower than said constant value of the starting current based upon the detected voltage and the second reference voltage. Both the first and second reference voltages are controlled to be constant voltages.
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BACKGROUND OF THE INVENTION
Synthesis of many retroviral protease and renin inhibitors containing a hydroxyethylamine, hydroxyethylurea or hydroxyethylsulfonamide isostere include the preparation of a key chiral amine intermediate. The synthesis of the key chiral amine requires a multi-step synthesis starting from a chiral amino acid such as L-phenylalanine. The key chiral amine intermediate can be prepared by diastereoselective reduction of an intermediate amino chloromethylketone or amine opening of a chiral epoxide intermediate. The present invention relates to a cost effective method of obtaining enantiomerically, diastereomerically and chemically pure chiral amine intermediate. This method is applicable for large scale (multikilogram) productions.
Roberts et al. (Science, 248, 358 (1990)), Krohn et al. (J. Med. Chem. 344, 3340 (1991)) and Getman et al. (J. Med. Chem., 346, 288 (1993)) disclosed the synthesis of protease inhibitors containing the hydroxyethylamine or hydroxyethylurea isostere which include the opening of an epoxide generated in a multi-step synthesis starting from an amino acid. These methods also contain steps which include diazomethane and the reduction of an amino chloromethyl ketone intermediate to an amino alcohol prior to formation of the epoxide. The overall yield of these syntheses are low and the use of explosive diazomethane additionally prevents such methods from being commercially acceptable.
Tinker et al. (U.S. Pat. No. 4,268,688) disclosed a catalytic process for the asymmetric hydroformylation to prepare optically active aldehydes from unsaturated olefins. Similarly, Reetz et al. (U.S. Pat. No. 4,990,669) disclosed the formation of optically active alpha amino aldehydes through the reduction of alpha amino carboxylic acids or their esters with lithium aluminum hydride followed by oxidation of the resulting protected beta amino alcohol by dimethyl sulfoxide/oxalyl chloride or chromium trioxide/pyridine. Alternatively, protected alpha amino carboxylic acids or esters thereof can be reduced with diisobutylaluminum hydride to form the protected amino aldehydes.
Reetz et al. (Tet. Lett., 30, 5425 (1989) disclosed the use of sulfonium and arsonium ylides and their reactions of protected α-amino aldehydes to form aminoalkyl epoxides. This method suffers from the use of highly toxic arsonium compounds or the use of combination of sodium hydride and dimethyl sulfoxide which is extremely hazardous in large scale. Sodium hydride and DMSO are incompatible (Sax, N. I., "Dangerous Properties of Industrial Materials", 6th Ed., Van Nostrand Reinhold Co., 1984, p. 433). Violent explosions have been reported on the reaction of sodium hydride and excess DMSO ("Handbook of Reactive Chemical Hazards", 3rd Ed., Butterworths, 1985, p. 295).
Matteson et al. (Synlett., 1991, 631) reported the addition of chloromethyllithium or bromomethyllithium to racemic aldehydes. J. Ng et al. (WO 93/23388 and PCT/US94/12201, both incorporated herein by reference in their entirety) disclose methods of preparing chiral epoxide, chiral cyanohydrin, chiral amine and other chiral intermediates useful in the preparation of retroviral protease inhibitors.
Various enzyme inhibitors, such as renin inhibitors and HIV protease inhibitors, have been prepared using the above described methods or variations thereof. EP 468641, EP 223437, EP 389898 and U.S. Pat. No. 4,599,198 for example describe the preparation of hydroxyethylamine isostere containing renin inhibitors. U.S. Pat. No. 5,157,041, WO 94/04492 and WO 92/08701 (each of which is incorporated herein by reference in its entirety) for example describe the preparation of hydroxyethylamine, hydroxyethylurea or hydroxyethylsulfonamide isostere containing retroviral protease inhibitors.
SUMMARY OF THE INVENTION
Human immunodeficiency virus (HIV), the causative agent of acquired immunodeficiency syndrome (AIDS), encodes three enzymes, including the well-characterized proteinase belonging to the aspartic proteinase family, the HIV protease. Inhibition of this enzyme is regarded as a promising approach for treating AIDS. One potential strategy for inhibitor design involves the introduction of hydroxyethylene transition-state analogs into inhibitors. Inhibitors adapting a hydroxyethylamine, hydroxyethylurea or hydroxyethylsulfonamide isostere are found to be highly potent inhibitors of HIV proteases. Despite the potential clinical importance of these compounds, the synthesis of these compounds are difficult and costly due to the number of chiral centers. Efficient processes for preparing large scale (multikilogram quantities) of such inhibitors is needed for development, clinical studies and cost effective pharmaceutical preparations.
This invention improves the synthesis of intermediates which are readily amenable to the large scale preparation of chiral hydroxyethylamine, hydroxyethylurea or hydroxyethylsulfonamide retroviral protease, renin or other aspartyl protease inhibitors. Specifically, the method includes precipitating, crystallizing or recrystallizing a salt of the desired chiral amine intermediate.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to a method of preparation of retroviral protease inhibitor that allows the preparation of commercial quantities of intermediates of the formulae ##STR1## wherein R 1 , R 3 , P 1 and P 2 are as defined below. Typical preparations of one diastereomer from enantiomerically pure starting materials, such as L-phenylalanine or D-phenylalanine, using methods as described herein and elsewhere result in enantiomeric mixtures of the alcohol containing carbon (--CHOH--) ranging from about 50:50 to about 90:10. Isolation of the desired enantiomer usually involves chromatographic separation. Alternatively, the enantiomeric mixture is used without separation and enantiomerically pure material is obtained at a later step in the synthesis of the inhibitors. These approaches increase the time and cost involved in the manufacture of a pharmaceutical preparation. Chromatographic separations increase the cost of manufacture. Using impure materials increases the amount of other reactants used in later steps of the inhibitor synthesis, and increases the amount of side products and waste produced in the later steps. Furthermore, these compounds often show indications of poor stability and may not be suitable for storage or shipment in large quantity (multikilograms) for long periods of time. Storage and shipment stability of such compounds is particularly important when the manufacture of the pharmaceutical preparation is carried out at different locations and/or in different environments. Alternatively, the amine can be protected with an amine protecting group, such as tert-butoxycarbonyl, benzyloxycarbonyl and the like, as described below and purified, such as by chromatography, crystallization and the like, followed by deprotection of the amine. This alternative adds more steps to the overall synthesis of the inhibitors and increases the manufacturing costs.
The present invention relates to a simple, economical process of isolating substantially enantiomerically and/or diastereomerically pure forms of Formula I. The process involves forming and isolating a salt of Formula I from crude reaction mixtures. The salt can be formed in the reaction mixture from which it precipitates. The precipitate can then be crystallized or recrystallized from the appropriate solvent system, such as ethanol, methanol, heptane, hexane, dimethylether, methyl-tert-butylether, ethyl acetate and the like or mixtures thereof. Alternatively, the reaction mixture solvent can be removed, such as in vacuo, and dissolved in a more appropriate solvent or mixture of solvents, such as methanol, ethanol, toluene, xylene, methylene chloride, carbon tetrachloride, hexane, heptane, petroleum ethers, dimethylether, ethyl acetate, methyl-tert-butylether, tetrahydrofuran, and the like or mixtures thereof. This may also permit removal, such as by filtration or extraction, of undesired materials from the reaction mixture, such as salts, side products, and the like. After the crude reaction mixture is dissolved, then the salt of Formula I can be precipitated or crystallized and recrystallized if desired or necessary. Formation, precipitation, crystallization and/or recrystallization of such salts can also be accomplished using water and water miscible or soluble organic solvent(s) mixtures, such as water/methanol, water/ethanol, and the like.
A salt of Formula I is prepared by the addition of an organic or inorganic acid, preferably in at least an equimolar quantities and more preferably in greater than equimolar quantities, directly to the reaction mixture or to the crude reaction mixture in solution as described above. Such salts may be monovalent, divalent or trivalent acid salts, may be monoprotic, diprotic, or triprotic, may be mixed or complex salts, or combinations thereof. Preferred organic acids which may be employed to form salts of Formula I include but are not limited to the following: acetic acid, aconitatoc acid, adipic acid, alginic acid, citric acid, aspartic acid, benzoic acid, benzenesulfonic acid, butyric acid, camphoric acid, camphorsulfonic acid, digluconic acid, isocitric acid, cyclopentylpropionic acid, undecanoic acid, malaic acid, dodecylsulfonic acid, ethanesulfonic acid, malic acid, glucoheptanoic acid, heptanoic acid, hexanoic acid, fumaric acid, 2-hydroxyethanesulfonic acid, lactic acid, maleic acid, mandelic acid, methanesulfonic acid, nicotinic acid, oxalacetic acid, 2-naphthalenesulfonic acid, oxalic acid, palmitic acid, pectinic acid, 3-phenylpropionic acid, picric acid, pivalic acid, propionic acid, succinic acid, glycerophosphoric acid, tannic acid, trifluoroacetic acid, toluenesulfonic acid, tartaric acid, diacetyltartaric acid, dibenzoyltartaric acid, ditoluyltartaric acid and the like. More preferred organic acids include acetic acid, camphorsulfonic acid, toluenesulfonic acid, methanesulfonic acid, malic acid, tartaric acid, mandelic acid, trifluoroacetic acid and oxalic acid. Most preferred organic acids include acetic acid, oxalic acid and tartaric acid. Racemic mixtures or optically pure isomers of an organic acid may be used, such as D, L, DL, meso, erythro, threo, and the like isomers. Preferred inorganic acids which may be employed to form salts of Formula I include but are not limited to the following: hydrochloric acid, hydrobromic acid, phosphoric acid, sulfurous acid, sulfuric acid and the like. A more preferred inorganic acid is hydrochloric acid.
The salts of Formula I and in particular crystalline salts of Formula I of the present invention are typically more stable under normal storage and shipping conditions than Formula I.
Formula I of the present invention means the formula ##STR2## wherein R 1 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl or aralkyl radicals, which are optionally substituted with alkyl, halogen, NO 0 , OR 9 or SR 9 , where R 9 represents hydrogen, alkyl, aryl or aralkyl. Preferably, R 1 is alkyl, cycloalkylalkyl or aralkyl radicals, which are optionally substituted with alkyl, halogen, NO 2 , OR 9 or SR 9 , where R 9 represents hydrogen, alkyl, aryl or aralkyl. Most preferably, R 1 is 2-(methylthio)ethyl, phenylthiomethyl, benzyl, (4-fluorophenyl)methyl, 2-naphthylmethyl or cyclohexylmethyl radicals.
R 3 represents hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl or N-mono- or N,N-disubstituted aminoalkyl radicals, wherein said substituents are alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, or heterocycloalkylalkyl radicals, or in the case of a disubstituted aminoalkyl radical, said substituents along with the nitrogen atom to which they are attached, form a heterocycloalkyl or a heteroaryl radical. Preferably, R 3 represents hydrogen, alkyl, cycloalkyl, cycloalkylalkyl or aralkyl radicals. More preferably, R 3 represents hydrogen, propyl, butyl, isobutyl, isoamyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclohexylmethyl, cyclopentylmethyl, phenylethyl or benzyl radicals. Most preferably, R 3 represents radicals as defined above which contain no alpha-branching, e.g., as in an isopropyl radical or a t-butyl radical. The preferred radicals are those which contain a --CH 2 --moiety between the nitrogen and the remaining portion of the radical. Such preferred groups include, but are not limited to, benzyl, isobutyl, n-butyl, isoamyl, cyclohexylmethyl, cyclopentylmethyl and the like.
P 1 and P 2 are each independently hydrogen or amine protecting groups, including but not limited to, aralkyl, substituted aralkyl, cycloalkenylalkyl and substituted cycloalkenylalkyl, allyl, substituted allyl, acyl, alkoxycarbonyl, aralkoxycarbonyl and silyl. Examples of aralkyl include, but are not limited to benzyl, 1-phenylethyl, ortho-methylbenzyl, trityl and benzhydryl, which can be optionally substituted with halogen, alkyl of C 1 -C 8 , alkoxy, hydroxy, nitro, alkylene, acylamino and acyl. Examples of aryl groups include phenyl, naphthalenyl, indanyl, anthracenyl, durenyl, 9-(9-phenylfluorenyl) and phenanthrenyl, which can be optionally substituted with halogen, alkyl of C 1 -C 8 , alkoxy, hydroxy, nitro, alkylene, acylamino and acyl. Suitable acyl groups include carbobenzoxy, t-butoxycarbonyl, iso-butoxycarbonyl, benzoyl, substituted benzoyl such as 2-methylbenzoyl, 2,6-dimethylbenzoyl 2,4,6-trimethylbenzoyl and 2,4,6-triisopropylbenzoyl, 1-naphthoyl, 2-naphthoyl butyryl, acetyl, tri-fluoroacetyl, tri-chloroacetyl, phthaloyl and the like.
Additionally, P 1 and P 2 protecting groups can form a heterocyclic ring system with the nitrogen to which they are attached, for example, 1,2-bis(methylene)benzene (i.e., 2-isoindolinyl), phthalimidyl, succinimidyl, maleimidyl and the like and where these heterocyclic groups can further include adjoining aryl and cycloalkyl rings. In addition, the heterocyclic groups can be mono-, di- or tri-substituted, e.g., nitrophthalimidyl.
Suitable carbamate protecting groups include, but are not limited to, methyl and ethyl carbamate; 9-fluorenylmethyl carbamate; 9-(2-Sulfo)fluorenylmethyl carbamate; 9-(2,7-dibromo)fluorenylmethyl carbamate; 2,7-di-t-butyl- 9-(10,10-dioxo-10,10,10-tetrahydrothioxanthyl)methyl carbamate; 4-methoxyphenacyl carbamate; 2,2,2-trichloroethyl carbamate; 2-trimethylsilylethyl carbamate; 2-phenylethyl carbamate; 1-(1-adamantyl)-1-methylethyl carbamate; 1, f-dimethyl-2-haloethyl carbamate; 1,1-dimethyl-2,2-dibromoethyl carbamate; 1,1-dimethyl-2,2,2-trichloroethyl carbamate; 1-methyl-1-(4-biphenylyl)-ethyl carbamate; 1-(3,5-di-t-butylphenyl)-1-methylethyl carbamate; 2-(2'-and 4'-pyridyl)ethyl carbamate; 2-(N,N-dicyclohexylcarboxamido) ethyl carbamate; t-butyl carbamate; 1-adamantyl carbamate; vinyl carbamate; allyl carbamate; 1-isopropylallyl carbamate; cinnamyl carbamate; 4-nitrocinnamyl carbamate; 8-quinolyl carbamate; N-hydroxypiperidinyl carbamate; alkyldithio carbamate; benzyl carbamate; p-methoxybenzyl carbamate; p-nitrobenzyl carbamate; p-bromobenzyl carbamate; p-chlorobenzyl carbamate; 2,4-dichlorobenzyl carbamate; 4-methylsulfinylbenzyl carbamate; 9-anthrylmethyl carbamate; diphenylmethyl carbamate; 2-methylthioethyl carbamate; 2-methylsulfonylethyl carbamate; 2-(p-toluenesulfonyl)ethyl carbamate; 2-(1,3-dithianyl)methyl carbamate; 4-methylthiophenyl-2,4-dimethylthiophenyl, 2-phosphonioethyl carbamate; 2-triphenylphosphonioisopropyl carbamate; 1,1-dimethyl-2-cyanoethyl carbamate; m-chloro-p-acyloxybenzyl carbamate; p-(dihydroxyboryl)benzyl carbamate; 5-benzoisoxazolylmethyl carbamate; 2-(trifluoromethyl)-6-chromonylmethyl carbamate; m-nitrophenyl carbamate; 3,5-dimethoxybenzyl carbamate; o-nitrobenzyl carbamate; 3,4-dimethoxy-6-nitrobenzyl carbamate; phenyl(o-nitrophenyl)methyl carbamate; phenothiazinyl-(10)-carbonyl derivative; N'-p-toluenesulfonylaminocarbonyl derivative; N'-phenylaminothiocarbonyl derivative t-amyl carbamate; S-benzyl thiocarbamate; p-cyanobenzyl carbamate; cyclobutyl carbamate; cyclohexyl carbamate; cyclopentyl carbamate; cyclopropylmethyl carbamate; p-decyloxybenzyl carbamate; diisopropylmethyl carbamate; 2,2-dimethoxycarbonylvinyl carbamate; o-(N,N-dimethylcarboxamido)benzyl carbamate; 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate; 1,1-dimethylpropynyl carbamate; di(2-pyridyl)methyl carbamate; 2-furanylmethyl carbamate; 2-iodoethyl carbamate; isobornyl carbamate; isobutyl carbamate; isonicotinyl carbamate; p-(p'-methoxyphenylazo)benzyl carbamate; 1-methylcyclobutyl carbamate; 1-methylcyclohexyl carbamate; 1-methyl-1-cyclopropylmethyl carbamate; 1-methyl-1-(3,5-dimethoxyphenyl)ethyl carbamate; 1-methyl-1-(p-phenylazophenyl)ethyl carbamate; and 1-methyl-1-phenylethyl carbamate. T. Greene and P. Wuts ("Protective Groups In Organic Synthesis," 2nd Ed., John Wiley & Sons, Inc. (1991)) describe the preparation and cleavage of such carbamate protecting groups.
The term silyl refers to a silicon atom substituted by one or more alkyl, aryl and aralkyl groups. Suitable silyl protecting groups include, but are not limited to, trimethylsilyl, triethylsilyl, tri-isopropylsilyl, tert-butyldimethylsilyl, dimethylphenylsilyl, 1,2-bis(dimethylsilyl)benzene, 1,2-bis(dimethylsilyl)ethane and diphenylmethylsilyl. Silylation of the amine functions to provide mono- or bis-disilylamine can provide derivatives of the aminoalcohol, amino acid, amino acid esters and amino acid amide. In the case of amino acids, amino acid esters and amino acid amides, reduction of the carbonyl function provides the required mono- or bis-silyl aminoalcohol. Silylation of the amino-alcohol can lead to the N,N,O-tri-silyl derivative. Removal of the silyl function from the silyl ether function is readily accomplished by treatment with, for example, a metal hydroxide or ammonium fluoride reagent, either as a discrete reaction step or in situ during the preparation of the amino aldehyde reagent. Suitable silylating agents are, for example, trimethylsilyl chloride, tert-buty-dimethylsilyl chloride, phenyldimethylsilyl chloride, diphenylmethylsilyl chloride or their combination products with imidazole or DMF. Methods for silylation of amines and removal of silyl protecting groups are well known to those skilled in the art. Methods of preparation of these amine derivatives from corresponding amino acids, amino acid amides or amino acid esters are also well known to those skilled in the art of organic chemistry including amino acid/amino acid ester or aminoalcohol chemistry.
Preferably P 1 is aralkyl, substituted aralkyl, alkylcarbonyl, aralkylcarbonyl, arylcarbonyl, alkoxycarbonyl or aralkoxycarbonyl, and P 2 is aralkyl or substituted aralkyl. Alternatively, when P 1 is alkoxycarbonyl or aralkoxycarbonyl, P 2 can be hydrogen. More preferably, P 1 is t-butoxycarbonyl, phenylmethoxycarbonyl, (4-methoxyphenyl)methoxycarbonyl or benzyl, and P 2 is hydrogen or benzyl.
Because the same synthetic and purification procedures are applicable to the preparation of each of the four possible diastereomers of Formula I, provided the proper chiral amino acid starting material is utilized, Formula I though shown in one configuration is intended to encompass all four diastereomers individually. Thus, the preparation procedures described herein and the definitions of R 1 , R 3 , P 1 and P 2 also apply to the other three configurational isomers ##STR3##
Protected amino epoxides of the formula ##STR4## protected amino alpha-hydroxycyanides and acids of the formula ##STR5## wherein X is --CN, --CH 2 NO 2 or --COOH, protected alpha-aminoaldehyde intermediates of the formula ##STR6## and protected chiral alpha-amino alcohols of the formula ##STR7## wherein P 1 , P 2 and R 1 are as defined above, are also described herein.
As utilized herein, the term "amino epoxide" alone or in combination, means an amino-substituted alkyl epoxide wherein the amino group can be a primary, or secondary amino group containing substituents selected from hydrogen, alkyl, aryl, aralkyl, alkenyl, alkoxycarbonyl, aralkoxycarbonyl, cycloalkenyl, silyl, cycloalkylalkenyl radicals and the like and the epoxide can be alpha to the amine. The term "amino aldehyde" alone or in combination, means an amino-substituted alkyl aldehyde wherein the amino group can be a primary, or secondary amino group containing substituents selected from hydrogen, alkyl, aryl, aralkyl, alkenyl, aralkoxycarbonyl, alkoxycarbonyl, cycloalkenyl, silyl, cycloalkylalkenyl radicals and the like and the aldehyde can be alpha to the amine. The term "alkyl", alone or in combination, means a straight-chain or branched-chain alkyl radical containing from 1 to 10, preferably from 1 to 8, more preferably from 1 to 5 carbon atoms. Examples of such radicals include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl, octyl and the like. The term "alkenyl", alone or in combination, means a straight-chain or branched-chain hydrocarbon radial having one or more double bonds and containing from 2 to 10 carbon atoms, preferably from 2 to 8, more preferably from 2 to 5 carbon atoms. Examples of suitable alkenyl radicals include ethenyl, propenyl, allyl, 1,4-butadienyl and the like. The term "alkynyl", alone or in combination, means a straight-chain hydrocarbon radical having one or more triple bonds and containing from 2 to about 10, preferably from 2 to 8, more preferably from 2 to 5 carbon atoms. Examples of alkynyl radicals include ethynyl, propynyl, (propargyl), butynyl and the like. The term "alkoxy", alone or in combination, means an alkyl ether radical wherein the term alkyl is as defined above. Examples of suitable alkyl ether radicals include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy and the like. The term "cycloalkenyl", alone or in combination, means an alkyl radical which contains from 5 to 8, preferably 5 to 6 carbon atoms, is cyclic and contains at least one double bond in the ring which is non-aromatic in character. Examples of such cycloalkenyl radicals include cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, dihydrophenyl and the like. The term "cycloalkenylalkyl" means cycloalkenyl radical as defined above which is attached to an alkyl radical as defined above. The term "cycloalkyl", alone or in combination, means a cyclic alkyl radical which contains from about 3 to about 8, preferably 3 to 6, more preferably 5 to 6 carbon atoms. The term "cycloalkylalkyl" means an alkyl radical as defined above which is substituted by a cycloalkyl radical as defined above. Examples of such cycloalkyl radicals include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. The term "aryl", alone or in combination, means a phenyl or naphthyl radical either of which is optionally substituted by one or more alkyl, alkoxy, halogen, hydroxy, amino, nitro and the like, as well as p-tolyl, 4-methoxyphenyl, 4-(tert-butoxy)phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-hydroxyphenyl, 1-naphthyl, 2-naphthyl, and the like. The term "aralkyl", alone or in combination, means an alkyl radical as defined above substituted by an aryl radical as defined above, such as benzyl, 1-phenylethyl and the like. Examples of substituted aralkyl include 3,5-dimethoxybenzyl, 3,4-dimethoxybenzyl, 2,4-dimethoxybenzyl, 3,4,5-trimethoxybenzyl, 4-nitrobenzyl, 2,6-dichlorobenzyl, 4-(chloromethyl)benzyl, 2-(bromomethyl)benzyl, 3-(chloromethyl)benzyl, 4-chlorobenzyl, 3-chlorobenzyl, 2-(chloromethyl)benzyl, 6-chloropiperonyl, 2-chlorobenzyl, 4-chloro-2-nitrobenzyl, 2-chloro-6-fluorobenzyl, 2-(chloromethyl)-4,5-dimethylbenzyl, 6-(chloromethyl)duren-3-ylmethyl, 10-(chloromethyl)anthracen-9-ylmethyl, 4-(chloromethyl)-2,5-dimethylbenzyl, 4-(chloromethyl)-2,5-dimethoxybenzyl, 4-(chloromethyl)anisol-2-ylmethyl, 5-(chloromethyl)-2,4-dimethylbenzyl, 4-(chloromethyl)mesitylen-2-ylmethyl, 4-acetyl-2,6-dichlorobenzyl, 2-chloro-4-methylbenzyl, 3,4-dichlorobenzyl, 6-chlorobenzo-1,3-dioxan-8-ylmethyl, 4-(2,6-dichlorobenzylsulphonyl)benzyl, 4-chloro-3-nitrobenzyl, 3-chloro-4-methoxybenzyl, 2-hydroxy-3-(chloromethyl)-5-methylbenzyl and the like. The term aralkoxycarbonyl means an aralkoxyl group attached to a carbonyl. Carbobenzoxy is an example of aralkoxycarbonyl. The term "heterocyclic" means a saturated or partially unsaturated monocyclic, bicyclic or tricyclic heterocycle having 5 to 6 ring members in each ring and which contains one or more heteroatoms as ring atoms, selected from nitrogen, oxygen, silicon and sulphur, which is optionally substituted on one or more carbon atoms by halogen, alkyl, alkoxy, oxo, and the like, and/or on a secondary nitrogen atom (i.e., --NH--) by alkyl, aralkoxycarbonyl, alkanoyl, phenyl or phenylalkyl or on a tertiary nitrogen atom (i.e. ═N--) by oxido. "Heteroaryl" means an aromatic monocyclic, bicyclic, or tricyclic heterocycle which contains the heteroatoms and is optionally substituted as defined above with respect to the definition of aryl. Examples of such heterocyclic groups are pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiamorpholinyl, pyrrolyl, phthalimide, succinimide, maleimide, and the like. Also included are heterocycles containing two silicon atoms simultaneously attached to the nitrogen and joined by carbon atoms. The term "alkylamino" alone or in combination, means an amino-substituted alkyl group wherein the amino group can be a primary, or secondary amino group containing substituents selected from hydrogen, alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl radicals and the like. The term "halogen" means fluorine, chlorine, bromine or iodine. The term dihaloalkyl means two halogen atoms, the same or different, substituted on the same carbon atom. The term "oxidizing agent" includes a single agent or a mixture of oxidizing reagents. Examples of mixtures of oxidizing reagents include sulfur trioxide-pyridine/dimethylsulfoxide, oxalyl chloride/dimethyl sulfoxide, acetyl chloride/dimethyl sulfoxide, acetyl anhydride/dimethyl sulfoxide, trifluoroacetyl chloride/dimethyl sulfoxide, toluenesulfonyl bromide/dimethyl sulfoxide, phosphorous pentachloride/dimethyl sulfoxide and isobutylchloroformate/dimethyl sulfoxide.
A general Scheme for the preparation of amino epoxides, useful as intermediates in the synthesis of HIV protease inhibitors is shown in Scheme 1 below. ##STR8##
An economical and safe large scale method of preparation of protease inhibitors of the present invention can alternatively utilize amino acids or amino alcohols to form N,N-protected alpha aminoalcohol of the formula ##STR9## wherein P 1 , P 2 and R 1 are described above.
Whether the compounds of Formula II are formed from amino acids or aminoalcohols, such compounds have the amine protected with groups P 1 and p 2 as previously identified. The nitrogen atom can be alkylated such as by the addition of suitable alkylating agents in an appropriate solvent in the presence of base.
Alternate bases used in alkylation include sodium hydroxide, sodium bicarbonate, potassium hydroxide, lithium hydroxide, potassium carbonate, sodium carbonate, cesium hydroxide, magnesium hydroxide, calcium hydroxide or calcium oxide, or tertiary amine bases such as triethyl amine, diisopropylethylamine, pyridine, N-methylpiperidine, dimethylaminopyridine and azabicyclononane. Reactions can be homogenous or heterogenous. Suitable solvents are water and protic solvents or solvents miscible with water, such as methanol, ethanol, isopropyl alcohol, tetrahydrofuran and the like, with or without added water. Dipolar aprotic solvents may also be used with or without added protic solvents including water. Examples of dipolar aprotic solvents include acetonitrile, dimethylformamide, dimethyl acetamide, acetamide, tetramethyl urea and its cyclic analog, dimethylsulfoxide, N-methylpyrrolidone, sulfolane, nitromethane and the like. Reaction temperature can range between about -20° to 100° C. with the preferred temperature of about 25°-85° C. The reaction may be carried out under an inert atmosphere such as nitrogen or argon, or normal or dry air, under atmospheric pressure or in a sealed reaction vessel under positive pressure. The most preferred alkylating agents are benzyl bromide or benzyl chloride or monosubstituted aralkyl halides or polysubstituted aralkyl halides. Sulfate or sulfonate esters are also suitable reagents to provide the corresponding benzyl analogs and they can be preformed from the corresponding benzyl alcohol or formed in situ by methods well known to those skilled in the art. Trityl, benzhydryl, substituted trityl and substituted benzhydryl groups, independently, are also effective amine protecting groups P 1 , P 2 ! as are allyl and substituted allyl groups. Their halide derivatives can also be prepared from the corresponding alcohols by methods well known to those skilled in the art such as treatment with thionyl chloride or bromide or with phosphorus tri- or pentachloride, bromide or iodide or the corresponding phosphoryl trihalide. Examples of groups that can be substituted on the aryl ring include alkyl, alkoxy, hydroxy, nitro, halo and alkylene, amino, mono- and dialkyl amino and acyl amino, acyl and water solubilizing groups such as phosphonium salts and ammonium salts. The aryl ring can be derived from, for example, benzene, napthelene, indane, anthracene, 9-phenylfluorenyl, durene, phenanthrene and the like. In addition, 1,2-bis (substituted alkylene) aryl halides or sulfonate esters can be used to form a nitrogen containing aryl or non-aromatic heterocyclic derivative with P 1 and P 2 ! or bis-heterocycles. Cycloalkylenealkyl or substituted cyloalkylene radicals containing 6-10 carbon atoms and alkylene radicals constitute additional acceptable class of substituents on nitrogen prepared as outlined above including, for example, cyclohexylenemethylene.
Compounds of Formula II can also be prepared by reductive alkylation by, for example, compounds and intermediates formed from the addition of an aldehyde with the amine and a reducing agent, reduction of a Schiff Base, carbinolamine or enamine or reduction of an acylated amine derivative. Reducing agents include metals platinum, palladium, palladium hydroxide, palladium on carbon, platinum oxide, rhodium and the like! with hydrogen gas or hydrogen transfer molecules such as cyclohexene or cyclohexadiene or hydride agents such as lithium aluminum hydride, sodium borohydride, lithium borohydride, sodium cyanoborohydride, diisobutylaluminum hydride or lithium tri-tert-butoxyaluminum hydride.
Additives such as sodium or potassium bromide, sodium or potassium iodide can catalyze or accelerate the rate of amine alkylation, especially when benzyl chloride was used as the nitrogen alkylating agent.
Phase transfer catalysis wherein the amine to be protected and the nitrogen alkylating agent are reacted with base in a solvent mixture in the presence of a phase transfer reagent, catalyst or promoter. The mixture can consist of, for example, toluene, benzene, ethylene dichloride, cyclohexane, methylene chloride or the like with water or a aqueous solution of an organic water miscible solvent such as THF. Examples of phase transfer catalysts or reagents include tetrabutylammonium chloride or iodide or bromide, tetrabutylammonium hydroxide, tri-butyloctylammonium chloride, dodecyltrihexylammonium hydroxide, methyltrihexylammonium chloride and the like.
A preferred method of forming substituted amines involves the aqueous addition of about 3 moles of organic halide to the amino acid or about 2 moles to the aminoalcohol. In a more preferred method of forming a protected amino alcohol, about 2 moles of benzylhalide in a basic aqueous solution is utilized. In an even more preferred method, the alkylation occurs at 50° C. to 80° C. with potassium carbonate in water, ethanol/water or denatured ethanol/water. In a more preferred method of forming a protected amino acid ester, about 3 moles of benzylhalide is added to a solution containing the amino acid.
The protected amino acid ester is additionally reduced to the protected amino alcohol in an organic solvent. Preferred reducing agents include lithium aluminum hydride, lithium borohydride, sodium borohydride, borane, lithium tri-tert-butoxyaluminum hydride, borane.THF complex. Most preferably, the reducing agent is diisobutylaluminum hydride (DiBAL-H) in toluene. These reduction conditions provide an alternative to a lithium aluminum hydride reduction.
Purification by chromatography is possible. In the preferred purification method the alpha amino alcohol can be purified by an acid quench of the reaction, such as with hydrochloric acid, and the resulting salt can be filtered off as a solid and the amino alcohol can be liberated such as by acid/base extraction.
The protected alpha amino alcohol is oxidized to form a chiral amino aldehyde of the formula ##STR10## Acceptable oxidizing reagents include, for example, sulfur trioxide-pyridine complex and DMSO, oxalyl chloride and DMSO, acetyl chloride or anhydride and DMSO, trifluoroacetyl chloride or anhydride and DMSO, methanesulfonyl chloride and DMSO or tetrahydrothiaphene-S-oxide, toluenesulfonyl bromide and DMSO, trifluoromethanesulfonyl anhydride (triflic anhydride) and DMSO, phosphorus pentachloride and DMSO, dimethylphosphoryl chloride and DMSO and isobutylchloroformate and DMSO. The oxidation conditions reported by Reetz et al Angew Chem., 99, p. 1186, (1987)!, Angew Chem. Int. Ed. Engl., 26, p. 1141, 1987) employed oxalyl chloride and DMSO at -78° C.
The preferred oxidation method described in this invention is sulfur trioxide pyridine complex, triethylamine and DMSO at room temperature. This system provides excellent yields of the desired chiral protected amino aldehyde usable without the need for purification i.e., the need to purify kilograms of intermediates by chromatography is eliminated and large scale operations are made less hazardous. Reaction at room temperature also eliminated the need for the use of low temperature reactor which makes the process more suitable for commercial production.
The reaction may be carried out under an inert atmosphere such as nitrogen or argon, or normal or dry air, under atmospheric pressure or in a sealed reaction vessel under positive pressure. Preferred is a nitrogen atmosphere. Alternative amine bases include, for example, tri-butyl amine, tri-isopropyl amine, N-methylpiperidine, N-methyl morpholine, azabicyclononane, diisopropylethylamine, 2,2,6,6-tetramethylpiperidine, N,N-dimethylaminopyridine, or mixtures of these bases Triethylamine is a preferred base. Alternatives to pure DMSO as solvent include mixtures of DMSO with non-protic or halogenated solvents such as tetrahydrofuran, ethyl acetate, toluene, xylene, dichloromethane, ethylene dichloride and the like. Dipolar aprotic co-solvents include acetonitrile, dimethylformamide, dimethylacetamide, acetamide, tetramethyl urea and its cyclic analog, N-methylpyrrolidone, sulfolane and the like. Rather than N,N-dibenzylphenylalaninol as the aldehyde precursor, the phenylalaninol derivatives discussed above can be used to provide the corresponding N-monosubstituted either P 1 or P 2 =H! or N,N-disubstituted aldehyde.
In addition, hydride reduction of an amide or ester derivative of the corresponding alkyl, benzyl or cycloalkenyl nitrogen protected phenylalanine, substituted phenylalanine or cycloalkyl analog of phenyalanine derivative can be carried out to provide a compound of Formula III. Hydride transfer is an additional method of aldehyde synthesis under conditions where aldehyde condensations are avoided, cf, Oppenauer Oxidation.
The aldehydes of this process can also be prepared by methods of reducing protected phenylalanine and phenylalanine analogs or their amide or ester derivatives by, e.g., sodium amalgam with HCl in ethanol or lithium or sodium or potassium or calcium in ammonia. The reaction temperature may be from about -20° C. to about 45° C., and preferably from abut 5° C. to about 25° C. Two additional methods of obtaining the nitrogen protected aldehyde include oxidation of the corresponding alcohol with bleach in the presence of a catalytic amount of 2,2,6,6-tetramethyl-l-pyridyloxy free radical. In a second method, oxidation of the alcohol to the aldehyde is accomplished by a catalytic amount of tetrapropylammonium perruthenate in the presence of N-methylmorpholine-N-oxide.
Alternatively, an acid chloride derivative of a protected phenylalanine or phenylalanine derivative as disclosed above can be reduced with hydrogen and a catalyst such as Pd on barium carbonate or barium sulphate, with or without an additional catalyst moderating agent such as sulfur or a thiol (Rosenmund Reduction).
An important aspect of the present invention is a reaction involving the addition of chloromethyllithium or bromomethyllithium to the α-amino aldehyde. Although addition of chloromethyllithium or bromomethyllithium to aldehydes is known, the addition of such species to racemic or chiral amino aldehydes to form aminoepoxides of the formula ##STR11## is novel. The addition of chloromethyllithium or bromomethyllithium to a chiral amino aldehyde with appropriate amino protecting groups is highly diastereoselective. Preferably, the chloromethyllithium or bromomethyllithium is generated in-situ from the reaction of the dihalomethane and n-butyl lithium. Acceptable methyleneating halomethanes include chloroiodomethane, bromochloromethane, dibromomethane, diiodomethane, bromofluoromethane and the like. The sulfonate ester of the addition product of, for example, hydrogen bromide to formaldehyde is also a methyleneating agent. Tetrahydrofuran is the preferred solvent, however alternative solvents such as toluene, dimethoxyethane, ethylene dichloride, methylene chloride can be used as pure solvents or as a mixture. Dipolar aprotic solvents such as acetonitrile, DMF, N-methylpyrrolidone are useful as solvents or as part of a solvent mixture. The reaction can be carried out under an inert atmosphere such as nitrogen or argon. Other organometallic reagents can be substituted for n-butyl lithium, such as methyl lithium, tert-butyl lithium, sec-butyl lithium, phenyl lithium, phenyl sodium, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, other amide bases, and the like. The reaction can be carried out at temperatures of between about -80° C. to 0° C. but preferably between about -80° C. to -20° C. The most preferred reaction temperatures are between -40° C. to -15° C. Reagents can be added singly but multiple additions are preferred in certain conditions. The preferred pressure of the reaction is atmospheric however a positive pressure is valuable under certain conditions such as a high humidity environment.
Alternative methods of conversion to the epoxides of this invention include substitution of other charged methylenation precursor species followed by their treatment with base to form the analogous anion. Examples of these species include trimethylsulfoxonium tosylate or triflate, tetramethylammonium halide, methyldiphenylsulfoxonium halide wherein halide is chloride, bromide or iodide.
The conversion of the aldehydes of this invention into their epoxide derivative can also be carried out in multiple steps. For example, the addition of the anion of thioanisole prepared from, for example, a butyl or aryl lithium reagent, to the protected aminoaldehyde, oxidation of the resulting protected aminosulfide alcohol with well known oxidizing agents such as hydrogen peroxide, tert-butyl hypochlorite, bleach or sodium periodate to give a sulfoxide. Alkylation of the sulfoxide with, for example, methyl iodide or bromide, methyl tosylate, methyl mesylate, methyl triflate, ethyl bromide, isopropyl bromide, benzyl chloride or the like, in the presence of an organic or inorganic base. Alternatively, the protected aminosulfide alcohol can be alkylated with, for example, the alkylating agents above, to provide a sulfonium salts that are subsequently converted into the subject epoxides with tert-amine or mineral bases.
The desired epoxides form, using most preferred conditions, diastereoselectively in ratio amounts of at least about an 85:15 ratio (S:R). The product can be purified by chromatography to give the diastereomerically and enantiomerically pure product but it is more conveniently used directly without purification to prepare HIV protease inhibitors.
The epoxide is then reacted, in a suitable solvent system, with an equal amount, or preferably an excess of, with R 3 NH 2 to form the amino alcohol of Formula I ##STR12## wherein R 3 is as defined above.
The reaction can be conducted over a wide range of temperatures, e.g., from about 10° C. to about 100° C., but is preferably, but not necessarily, conducted at a temperature at which the solvent begins to reflux. Suitable solvent systems include those wherein the solvent is an alcohol, such as methanol, ethanol, isopropanol, and the like, ethers such as tetrahydrofuran, dioxane and the like, and toluene, N,N-dimethylformamide, dimethyl sulfoxide, and mixtures thereof. A preferred solvent is isopropanol. Exemplary amines corresponding to the formula R 3 NH 2 include benzylamine, isobutylamine, n-butyl amine, isopentylamine, isoamylamine, cyclohexylmethylamine, cyclopentylmethylamine, naphthylmethylamine and the like. In some cases, R 3 NH 2 can be used as the solvent, such as iso-butylamine.
Alternatively, the protected amino aldehyde of Formula III can also be reacted with a cyanide salt, such as sodium cyanide or potassium cyanide to form a chiral cyanohydrin of the formula ##STR13## Preferably, a reaction rate enhancer, such as sodium bisulfite, is used to enhance the rate of cyanohydrin formation. Alternatively, trimethylsilylnitrile can be used to form a trimethylsilyloxycyano intermediate, which can be readily hydrolyzed to the cyanohydrin.
The reaction can be carried out at temperatures of between about -5° C. to 5° C. but preferably between about 0° C. to 5° C. The desired cyanohydrins form, using sodium cyanide and sodium bisulfite, diastereoselectively in ratio amounts of at least about an 88:12 ratio (S:R). The product can be purified by chromatography to give the diastereomerically and enantiomerically pure product.
The cyano group can be reduced to the amine of Formula V ##STR14## The reduction can be accomplished using a variety of reducing reagents, such as hydride transfer, metal reductions and catalytic hydrogenation which are well known to those skilled in the art. Examples of hydride reagents with and without heavy metal(s) or heavy metal salts as adjunct reagents include, for example, lithium aluminum hydride, lithium tri-tert-butoxyaluminum hydride, lithium trimethoxy-aluminum hydride, aluminum hydride, diborane (or borane), borane/THF, borane/dimethyl sulfide, borane/pyridine, sodium borohydride, lithium borohydride, sodium borohydride/cobalt salts, sodium borohydride/Raney-nickel, sodium borohydride/acetic acid and the like. Solvents for the reaction include, for the more reactive hydrides, THF, diethyl ether, dimethoxy ethane, diglyme, toluene, heptane, cyclohexane, methyl tert-butyl ether and the like. Solvents or solvent mixtures for reductions using reagents such as sodium borohydride, in addition to the non-protic solvents listed above, can include ethanol, n-butanol, tert-butyl alcohol, ethylene glycol and the like. Metal reductions include, for example, sodium and ethanol. Reaction temperatures can vary between solvent reflux and -20° C. An inert atmosphere such as nitrogen or argon is usually preferred especially where the possibility of flammable gas or solvent production/evolution is possible. Catalytic hydrogenation (metal catalyst plus hydrogen gas) can be carried out in the same solvents as above with metals or metal salts such a nickel, palladium chloride, platinum, rhodium, platinum oxide or palladium on carbon or other catalysts known to those skilled in the art. These catalysts can also be modified with, for example, phosphine ligands, sulfur or sulfur containing compounds or amines such as quinoline. Hydrogenations can be carried out at atmospheric pressure or at elevated pressures to about 1500 psi at temperatures between 0° to about 250° C. The most preferred reducing reagent is diborane.tetrahydrofuran, preferably at room temperature under an atmosphere of nitrogen and atmospheric pressure.
The amine of Formula V can then be reacted with R 3 L, wherein L is a leaving group selected from halo, tosylate, mesolate and the like, and R 3 represents alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aralkyl or heteroaralkyl. Alternatively, the primary amino group of Formula V can be reductively alkylated with an aldehyde to introduce the R3 group. For example, when R3 is an isobutyl group, treatment of Formula V with isobutyraldehyde under reductive amination conditions affords the desired Formula I. Similarly, when R3 is an isoamyl group, treatment of Formula V with isovaleraldehyde under reductive amination conditions affords the desired Formula I. Other aldehydes can be used to introduce various R3 groups. Reductive amination can be performed using a variety of reaction conditions well-known to those skilled in the art. For example, the reductive amination of Formula V with an aldehyde can be carried out with a reducing agent such as sodium cyanoborohydride or sodium borohydride in a suitable solvent, such as methanol, ethanol, tetrahydrofuran and the like. Alternatively, the reductive amination can be carried out using hydrogen in the presence of a catalyst such as palladium or platinum, palladium on carbon or platinum on carbon, or various other metal catalysts known to those skilled in the art, in a suitable solvent such as methanol, ethanol, tetrahydrofuran, ethyl acetate, toluene and the like.
Alternatively, the amine of Formula I can be prepared by reduction of the protected amino acid of formula ##STR15## (commercially available from Nippon Kayaku, Japan) to the corresponding alcohol of formula ##STR16## The reduction can be accomplished using a variety of reducing reagents and conditions. A preferred reducing reagent is diborane.tetrahydrofuran. The alcohol is then converted into a leaving group (L') by tosylation, mesylation or conversion into a halo group, such as chloro or bromo: ##STR17## Finally, the leaving group (L') is reacted with R 3 NH 2 as described above to form amino alcohol of Formula I. Alternatively, base treatment of the alcohol can result in the formation of the amino epoxide of Formula IV.
The above preparation of amino alcohol of Formula I is applicable to mixtures of optical isomers as well as resolved compounds. If a particular optical isomer is desired, it can be selected by the choice of starting material, e.g., L-phenylalanine, D-phenylalanine, L-phenylalaninol, D-phenylalaninol, D-hexahydrophenyl alaninol and the like, or resolution can occur at intermediate or final steps. Chiral auxiliaries such as one or two equivalents of camphor sulfonic acid, citric acid, camphoric acid, 2-methoxyphenylacetic acid and the like can be used to form salts, esters or amides of the compounds of this invention. These compounds or derivatives can be crystallized or separated chromatographically using either a chiral or achiral column as is well known to those skilled in the art.
A further advantage of the present process is that materials can be carried through the above steps without purification of the intermediate products. However, if purification is desired, the intermediates disclosed can be prepared and stored in a pure state.
The practical and efficient synthesis described here has been successfully scaled up to prepare large quantity of intermediates for the preparation of HIV protease inhibitors. It offers several advantages for multikilogram preparations: (1) it does not require the use of hazardous reagents such as diazomethane, (2) it requires no purification by chromatography, (3) it is short and efficient, (4) it utilizes inexpensive and readily available commercial reagents, (5) it produces enantiomerically pure alpha amino epoxides. In particular, the process of the invention produces enantiomerically-pure epoxide as required for the preparation of enantiomerically-pure intermediate for further synthesis of HIV protease inhibitors.
The amino epoxides were prepared utilizing the following procedure as disclosed in Scheme II below. ##STR18##
In Scheme II, there is shown a synthesis for the epoxide, chiral N, N,α-S-tris(phenylmethyl)-2S-oxiranemethan-amine. The synthesis starts from L-phenylalanine. The aldehyde is prepared in three steps from L-phenylalanine or phenylalaninol. L-Phenylalanine is converted to the N,N-dibenzylamino acid benzyl ester using benzyl bromide under aqueous conditions. The reduction of benzyl ester is carried out using diisobutylaluminum hydride (DIBAL-H) in toluene. Alternatively, lithium aluminum hydride may be used. Instead of purification by chromatography, the product is purified by an acid (hydrochloric acid) quench of the reaction, the hydrochloride salt is filtered off as a white solid and then liberated by an acid/base extraction. After one recrystallization, chemically and optically pure alcohol is obtained. Alternately, and preferably, the alcohol can be obtained in one step in 88% yield by the benzylation of L-phenylalaninol using benzylbromide under aqueous conditions. The oxidation of alcohol to aldehyde is also modified to allow for more convenient operation during scaleup. Instead of the standard Swern procedures using oxalyl chloride and DMSO in methylene chloride at low temperatures (very exothermic reaction), sulfur trioxide-pyridine/DMSO was employed (Parikh, J., Doering, W., J. Am. Chem. Soc., 89, p. 5505, 1967) which can be conveniently performed at room temperature to give excellent yields of the desired aldehyde with high chemical and enantiomer purity which does not require purification.
An important reaction involves the addition of chloromethyllithium or bromomethyllithium to the aldehyde. Although addition of chloromethyllithium or bromomethyllithium to aldehydes has been reported previously, the addition of such species to chiral α-amino aldehydes to form chiral-aminoepoxides is believed to be novel. Now, chloromethyllithium or bromomethyllithium is generated in-situ from chloroiodomethane(or bromochloromethane) or dibromomethane and n-butyl lithium at a temperature in a range from about -78° C. to about -10° C. in THF in the presence of aldehyde. The desired chlorohydrin or bromohydrin is formed as evidenced by TLC analyses. After warming to room temperature, the desired epoxide is formed diastereoselectively in a 85:15 ratio (S:R). The product can be purified by chromatography to give the diastereomerically pure product as a colorless oil but it is more conveniently used directly without purification.
Scheme III illustrates the preparation of the aminopropylurea (9) utilizing mixed protected amine of phenylalaninol, where BOC is t-butoxycarbonyl and Bn is benzyl. ##STR19##
Scheme IV illustrates an alternative preparation of the amino epoxide (5) utilizing a sulfur ylide. ##STR20##
The aminopropylurea (9) was also prepared utilizing the procedure as disclosed in Scheme V below. ##STR21## In Scheme V a mixed protected amine of phenylalaninal, where BOC is t-butoxycarbonyl and Bn is benzyl, was reacted with potassium cyanide to form the desired stereoisomeric cyanohydrin (12) in high yield. In additional to the stereospecificity of the cyanohydrin reaction, this process has the added advantage of being easier and less expensive because the temperature of the reactions need not be less than -5° C.
The aminourea (9) was also prepared utilizing the procedure as disclosed in Scheme VI below. ##STR22## The procedure in Scheme VI required only one protecting group, BOC, for the amine of the hydroxyamino acid. This procedure has the advantage of having the desired stereochemistry of the benzyl and hydroxy groups established in the starting material. Thus the chirality does not need to be introduced with the resulting loss of material due to preparation of diastereomers.
EXAMPLE 1
β-2- Bis(phenylmethyl)amino!benzenepropanol
METHOD 1: βS-2- Bis(phenylmethyl)amino!benzenepropanol from the DIBAL Reduction of N,N-bis(phenylmethyl)-L-Phenylalanine phenylmethyl ester
Step 1
A solution of L-phenylalanine (50.0 g, 0.302 mol), sodium hydroxide (24.2 g, 0.605 mol) and potassium carbonate (83.6 g, 0.605 mol) in water (500 mL) was heated to 97° C. Benzyl bromide (108.5 mL, 0.605 mol) was then slowly added (addition time--25 min). The mixture was stirred at 97° C. for 30 minutes under a nitrogen atmosphere. The solution was cooled to room temperature and extracted with toluene (2×250 mL). The combined organic layers were washed with water and brine, dried over magnesium sulfate, filtered and concentrated to an oil. The identity of the product was confirmed as follows. Analytical TLC (10% ethyl acetate/hexane, silica gel) showed major component at Rf value=0.32 to be the desired tribenzylated compound, N,N-bis(phenylmethyl) -L-phenylalanine phenylmethyl ester. This compound can be purified by column chromatography (silica gel, 15% ethyl acetate/hexane). Usually the product is pure enough to be used directly in the next step without further purification. 1 H NMR spectrum was in agreement with published literature. 1 H NMR (CDCL 3 ) ∂, 3.00 and 3.14 (ABX-system, 2H, J AB =14.1 Hz, J AX =7.3 Hz and J BX =5.9 Hz), 3.54 and 3.92 (AB-System, 4H, J AB =13.9 Hz), 3.71 (t, 1H, J=7.6 Hz), 5.11 and 5.23 (AB-System, 2H, J AB =12.3 Hz), and 7.18 (m, 20H). EIMS: m/z 434 (M-1).
Step 2
The benzylated phenylalanine phenylmethyl ester (0.302 mol) from the previous reaction was dissolved in toluene (750 mL) and cooled to -55° C. A 1.5M solution of DIBAL in toluene (443.9 mL, 0.666 mol) was added at a rate to maintain the temperature between -55° to -50° C. (addition time--1 hr). The mixture was stirred for 20 minutes under a nitrogen atmosphere and then quenched at -55° C. by the slow addition of methanol (37 ml). The cold solution was then poured into cold (5° C.) 1.5N HCl solution (1.8 L). The precipitated solid (approx. 138 g) was filtered off and washed with toluene. The solid material was suspended in a mixture of toluene (400 mL) and water (100 ml). The mixture was cooled to 5° C. and treated with 2.5N NaOH (186 mL) and then stirred at room temperature until solid dissolved. The toluene layer was separated from the aqueous phase and washed with water and brine, dried over magnesium sulfate, filtered and concentrated to a volume of 75 mL (89 g). Ethyl acetate (25 mL) and hexane (25 mL) were added to the residue upon which the desired alcohol product began to crystallize. After 30 min, an additional 50 mL hexane were added to promote further crystallization. The solid was filtered off and washed with 50 mL hexane to give 34.9 g of first crop product. A second crop of product (5.6 g) was isolated by refiltering the mother liquor. The two crops were combined and recrystallized from ethyl acetate (20 mL) and hexane (30 mL) to give 40 g of βS-2- Bis(phenylmethyl)amino!benzenepropanol, 40% yield from L-phenylalanine. An additional 7 g (7%) of product can be obtained from recrystallization of the concentrated mother liquor. TLC of product Rf=0.23 (10% ethyl acetate/hexane, silica gel); 1 H NMR (CDCl 3 ) ∂ 2.44 (m, 1H,), 3.09 (m, 2H), 3.33 (m, 1H), 3.48 and 3.92 (AB-System, 4H, J AB =13.3 Hz), 3.52 (m, 1H) and 7.23 (m, 15H); α! D 25 +42.4 (c 1.45, CH 2 Cl 2 ); DSC 77.67° C.; Anal. Calcd. for C 23 H 25 ON: C, 83.34;H, 7.60; N, 4.23. Found: C, 83.43;H, 7.59;N, 4.22. HPLC on chiral stationary phase: Cyclobond I SP column (250×4.6 mm I.D.), mobile phase: methanol/triethyl ammonium acetate buffer pH 4.2 (58:42, v/v), flow-rate of 0.5 ml/min, detection with detector at 230 nm and a temperature of 0° C. Retention time: 11.25 min., retention time of the desired product enantiomer: 12.5 min.
METHOD 2: Preparation of βS -2- Bis(phenylmethyl)amino! benzene-propanol from the N,N-Dibenzylation of L-Phenylalaninol
L-phenylalaninol (176.6 g, 1.168 mol) was added to a stirred solution of potassium carbonate (484.6 g, 3.506 mol) in 710 mL of water. The mixture was heated to 65° C. under a nitrogen atmosphere. A solution of benzyl bromide (400 g, 2.339 mol) in 3A ethanol (305 mL) was added at a rate that maintained the temperature between 60°-68° C. The biphasic solution was stirred at 65° C. for 55 min and then allowed to cool to 10° C. with vigorous stirring. The oily product solidified into small granules. The product was diluted with 2.0 L of tap water and stirred for 5 minutes to dissolve the inorganic by products. The product was isolated by filtration under reduced pressure and washed with water until the pH is 7. The crude product obtained was air dried overnight to give a semi-dry solid (407 g) which was recrystallized from 1.1 L of ethyl acetate/heptane (1:10 by volume). The product was isolated by filtration (at -8° C.), washed with 1.6 L of cold (-10° C.) ethyl acetate/heptane (1:10 by volume) and air-dried to give 339 g (88% yield) of βS-2- Bis(phenylmethyl)amino!benzene-propanol, Mp=71.5°-73.0° C. More product can be obtained from the mother liquor if necessary. The other analytical characterization was identical to compound prepared as described in Method 1.
EXAMPLE 2
αS- Bis(phenylmethyl)amino!benzenepropanaldehyde
METHOD 1
βS-2- Bis(phenylmethyl)amino!benzene-propanol (200 g, 0.604 mol) was dissolved in triethylamine (300 mL, 2.15 mol). The mixture was cooled to 12° C. and a solution of sulfur trioxide/pyridine complex (380 g, 2.39 mol) in DMSO (1.6 L) was added at a rate to maintain the temperature between 8°-17° C. (addition time--1.0 h). The solution was stirred at ambient temperature under a nitrogen atmosphere for 1.5 hour at which time the reaction was complete by TLC analysis (33% ethyl acetate/hexane, silica gel). The reaction mixture was cooled with ice water and quenched with 1.6 L of cold water (10°-15° C.) over 45 minutes. The resultant solution was extracted with ethyl acetate (2.0 L), washed with 5% citric acid (2.0 L), and brine (2.2 L), dried over MgSO 4 (280 g) and filtered. The solvent was removed on a rotary evaporator at 35°-40° C. and then dried under vacuum to give 198.8 g of αS- Bis-(phenylmethyl)amino!-benzenepropanaldehyde as a pale yellow oil (99.9%). The crude product obtained was pure enough to be used directly in the next step without purification. The analytical data of the compound were consistent with the published literature. α! D 25=-92.9° (c 1.87, CH 2 Cl 2 ); 1 H NMR (400 MHz, CDCl 3 ) ∂, 2.94 and 3.15 (ABX-System, 2H, J AB =13.9 Hz, J AX =7.3 Hz and J BX =6.2 Hz), 3.56 (t, 1H, 7.1 Hz), 3.69 and 3.82 (AB-system, 4H, J AB =13.7 Hz), 7.25 (m, 15H) and 9.72 (s, 1H); HRMS Calcd for (M+1) C 23 H 24 NO 330.450, found: 330.1836. Anal. Calcd. for C 23 H 23 ON: C, 83.86;H, 7.04;N, 4.25. Found: C, 83.64;H, 7.42;N, 4.19. HPLC on chiral stationary phase:(S,S) Pirkle-Whelk-O 1 column (250×4.6 mm I.D.), mobile phase: hexane/isopropanol (99.5:0.5, v/v), flow-rate: 1.5 ml/min, detection with UV detector at 210 nm. Retention time of the desired S-isomer: 8.75 min., retention time of the R-enantiomer 10.62 min.
METHOD 2
A solution of oxalyl chloride (8.4 ml, 0.096 mol) in dichloromethane (240 ml) was cooled to -74° C. A solution of DMSO (12.0 ml, 0.155 mol) in dichloromethane (50 ml) was then slowly added at a rate to maintain the temperature at -74° C. (addition time ˜1.25 hr). The mixture was stirred for 5 min. followed by addition of a solution of βS-2- bis(phenylmethyl)amino!benzene-propanol (0.074 mol) in 100 ml of dichloromethane (addition time--20 min., temp. -75° C. to -68° C.). The solution was stirred at -78° C. for 35 minutes under a nitrogen atmosphere. Triethylamine (41.2 ml, 0.295 mol) was then added over 10 min. (temp. -78° to -68° C.) upon which the ammonium salt precipitated. The cold mixture was stirred for 30 min. and then water (225 ml) was added. The dichloromethane layer was separated from the aqueous phase and washed with water, brine, dried over magnesium sulfate, filtered and concentrated. The residue was diluted with ethyl acetate and hexane and then filtered to further remove the ammonium salt. The filtrate was concentrated to give αS- bis(phenylmethyl)amino! benzenepropanaldehyde. The aldehyde was carried on to the next step without purification.
METHOD 3
To a mixture of 1.0 g(3.0 mmoles) of βS-2- bis(phenylmethyl)amino!benzenepropanol 0.531 g(4.53 mmoles) of N-methyl morpholine, 2.27 g of molecular sieves(4A) and 9.1 mL of acetonitrile was added 53 mg (0.15 mmoles) of tetrapropylammonium perruthenate(TPAP). The mixture was stirred for 40 minutes at room temperature and concentrated under reduced pressure. The residue was suspended in 15 mL of ethyl acetate, filtered through a pad of silica gel. The filtrate was concentrated under reduced pressure to give a product containing approximately 50% of αS-2- bis(phenylmethyl)amino!benzene propanaldehyde as a pale yellow oil.
METHOD 4
To a solution of 1.0 g (3.02 mmoles) of βS-2- bis(phenylmethyl)amino!benzenepropanol in 9.0 mL of toluene was added 4.69 mg (0.03 mmoles) of 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical (TEMPO), 0.32g(3.11 mmoles) of sodium bromide, 9.0 mL of ethyl acetate and 1.5 mL of water. The mixture was cooled to 0° C. and an aqueous solution of 2.87 mL of 5% household bleach containing 0.735 g(8.75 mmoles) of sodium bicarbonate and 8.53 mL of water was added slowly over 25 minutes. The mixture was stirred at 0° C. for 60 minutes. Two more additions (1.44 mL each) of bleach was added followed by stirring for 10 minutes. The two phase mixture was allowed to separate. The aqueous layer was extracted twice with 20 mL of ethyl acetate. The combined organic layer was washed with 4.0 mL of a solution containing 25 mg of potassium iodide and water(4.0 mL), 20 mL of 10% aqueous sodium thiosulfate solution and then brine solution. The organic solution was dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 1.34 g of crude oil containing a small amount of the desired product aldehyde, αS- bis(phenylmethyl)amino!benzenepropanaldehyde.
METHOD 5
Following the same procedures as described in Example 2 (Method 1) except 3.0 equivalents of sulfur trioxide pyridine complex was used and αS- bis(phenylmethyl)amino!benzenepropanaldehyde was isolated in comparable yields.
EXAMPLE 3
N,N,αS-Tris(phenylmethyl)-2S-oxiranemethanamine
METHOD 1
A solution of αS- Bis(phenylmethyl)amino!benzenepropanaldehyde (191.7 g, 0.58 mol) and chloroiodomethane (56.4 mL, 0.77 mol) in tetrahydrofuran (1.8 L) was cooled to -30° to -35° C. (colder temperature such as -70° C. also worked well but warmer temperatures are more readily achieved in large scale operations) in a stainless steel reactor under a nitrogen atmosphere. A solution of n-butyl lithium in hexane (1.6M, 365 mL, 0.58 mol) was then added at a rate that maintained the temperature below -25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. More additions of reagents were carried out in the following manner: (1) additional chloroiodomethane (17 mL) was added, followed by n-butyl lithium (110 mL) at <-25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. This was repeated once. (2) Additional chloroiodomethane (8.5 mL, 0.11 mol) was added, followed by n-butyl lithium (55 mL, 0.088 mol) at <-25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. This was repeated 5 times. (3) Additional chloroiodomethane (8.5 ML, 0.11 mol) was added, followed by n-butyl lithium (37 mL, 0.059 mol) at <-25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. This was repeated once. The external cooling was stopped and the mixture warmed to ambient temp. over 4 to 16 hours when TLC (silica gel, 20% ethyl acetate/hexane) indicated that the reaction was completed. The reaction mixture was cooled to 10° C. and quenched with 1452 g of 16% ammonium chloride solution (prepared by dissolving 232 g of ammonium chloride in 1220 mL of water), keeping the temperature below 23° C. The mixture was stirred for 10 minutes and the organic and aqueous layers were separated. The aqueous phase was extracted with ethyl acetate (2×500 mL). The ethyl acetate layer was combined with the tetrahydrofuran layer. The combined solution was dried over magnesium sulfate (220 g), filtered and concentrated on a rotary evaporator at 65° C. The brown oil residue was dried at 70° C. in vacuo (0.8 bar) for 1 h to give 222.8 g of crude material. (The crude product weight was >100%. Due to the relative instability of the product on silica gel, the crude product is usually used directly in the next step without purification). The diastereomeric ratio of the crude mixture was determined by proton NMR: (2S)/(2R): 86:14. The minor and major epoxide diastereomers were characterized in this mixture by tlc analysis (silica gel, 10% ethyl acetate/hexane), Rf=0.29 & 0.32, respectively. An analytical sample of each of the diastereomers was obtained by purification on silica-gel chromatography (3% ethyl acetate/hexane) and characterized as follows:
N,N,αS-Tris(phenylmethyl)-2S-oxiranemethanamine
1 H NMR (400 MHz, CDCl 3 ) ∂ 2.49 and 2.51 (AB-System, 1H, J AB =2.82), 2.76 and 2.77 (AB-System, 1H, J AB =4.03), 2.83 (m, 2H), 2.99 & 3.03 (AB-System, 1H, J AB =10.1 Hz), 3.15 (m, 1H), 3.73 & 3.84 (AB-System, 4H, J AB =14.00), 7.21 (m, 15H); 13 C NMR (400 MHz,CDCl 3 ) ∂ 139.55, 129.45, 128.42, 128.14, 128.09, 126.84, 125.97, 60.32, 54.23, 52.13, 45.99, 33.76; HRMS Calcd for C 24 H 26 NO (M+1) 344.477, found 344.2003.
N,N,αS-Tris(phenylmethyl)-2R-oxiranemethanamine
1 H NMR (300 MHz, CDCl 3 ) ∂ 2.20 (m, 1H), 2.59 (m, 1H), 2.75 (m, 2H), 2.97 (m, 1H), 3.14 (m, 1H), 3.85 (AB-System, 4H), 7.25 (m, 15H).HPLC on chiral stationary phase: Pirkle-Whelk-O 1 column (250×4.6 mm I.D.), mobile phase: hexane/isopropanol (99.5:0.5, v/v), flow-rate: 1.5 ml/min, detection with UV detector at 210 nm. Retention time of(8): 9.38 min., retention time of enantiomer of (4): 13.75 min.
METHOD 2
A solution of the crude aldehyde 0.074 mol and chloroiodomethane (7.0 ml, 0.096 mol) in tetrahydrofuran (285 ml) was cooled to -78° C., under a nitrogen atmosphere. A 1.6M solution of n-butyl lithium in hexane (25 ml, 0.040 mol) was then added at a rate to maintain the temperature at -75° C. (addition time--15 min.). After the first addition, additional chloroiodomethane (1.6 ml, 0.022 mol) was added again, followed by n-butyl lithium (23 ml, 0.037 mol), keeping the temperature at -75° C. The mixture was stirred for 15 min. Each of the reagents, chloroiodomethane (0.70 ml, 0.010 mol) and n-butyl lithium (5 ml, 0.008 mol) were added 4 more times over 45 min. at -75° C. The cooling bath was then removed and the solution warmed to 22° C. over 1.5 hr. The mixture was poured into 300 ml of saturated aq. ammonium chloride solution. The tetrahydrofuran layer was separated. The aqueous phase was extracted with ethyl acetate (1×300 ml). The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and concentrated to give a brown oil (27.4 g). The product could be used in the next step without purification. The desired diastereomer can be purified by recrystallization at a subsequent step. The product could also be purified by chromatography.
METHOD 3
A solution of αS- Bis(phenylmethyl)amino!benzenepropanaldehyde (178.84 g, 0.54 mol) and bromochloromethane (46 mL, 0.71 mol) in tetrahydrofuran (1.8 L) was cooled to -30° to -35° C. (colder temperature such as -70° C. also worked well but warmer temperatures are more readily achieved in large scale operations) in a stainless steel reactor under a nitrogen atmosphere. A solution of n-butyl lithium in hexane (1.6M, 340 mL, 0.54 mol) was then added at a rate that maintained the temperature below -25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. More additions of reagents were carried out in the following manner: (1) additional bromochloromethane (14 mL) was added, followed by n-butyl lithium (102 mL) at <-25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. This was repeated once. (2) Additional bromochloromethane (7 mL, 0.11 mol) was added, followed by n-butyl lithium (51 mL, 0.082 mol) at <-25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. This was repeated 5 times. (3) Additional bromochloromethane (7 mL, 0.11 mol) was added, followed by n-butyl lithium (51 mL, 0.082 mol) at <-25° C. After addition the mixture was stirred at -30° to -35° C. for 10 minutes. This was repeated once. The external cooling was stopped and the mixture warmed to ambient temp. over 4 to 16 hours when TLC (silica gel, 20% ethyl acetate/hexane) indicated that the reaction was completed. The reaction mixture was cooled to 10° C. and quenched with 1452 g of 16% ammonium chloride solution (prepared by dissolving 232 g of ammonium chloride in 1220 mL of water), keeping the temperature below 23° C. The mixture was stirred for 10 minutes and the organic and aqueous layers were separated. The aqueous phase was extracted with ethyl acetate (2×500 mL). The ethyl acetate layer was combined with the tetrahydrofuran layer. The combined solution was dried over magnesium sulfate (220 g), filtered and concentrated on a rotary evaporator at 65° C. The brown oil residue was dried at 70° C. in vacuo (0.8 bar) for 1 h to give 222.8 g of crude material.
METHOD 4
Following the same procedures as described in Example 3 (Method 3) except the reaction temperatures were at -20° C. The resulting N,N, αS-tris(phenylmethyl)-2S-oxiranemethanamine was a diastereomeric mixture of lesser purity then that of Method 3.
METHOD 5
Following the same procedures as described in Example 3 (Method 3) except the reaction temperatures were at -70°-78° C. The resulting N,N,αS-tris(phenylmethyl)-2S-oxiranemethanamine was a diastereomeric mixture, which was used directly in the subsequent steps without purification.
METHOD 6
Following the same procedures as described in Example 3 (Method 3) except a continuous addition of bromochloromethane and n-butyl lithium was used at -30° to -35° C. After the reaction and work up procedures as described in Example 3 (Method 3), the desired N,N,αS-tris(phenylmethyl)-2S-oxiranemethanamine was isolated in comparable yields and purities.
METHOD 7
Following the same procedures as described in Example 3 (Method 2) except dibromomethane was used instead of chloroiodomethane. After the reaction and work up procedures as described in Example 3 (method 2), the desired N,N,αS-tris(phenylmethyl)-2S-oxiranemethanamine was isolated.
EXAMPLE 4
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine
To a solution of crude N,N-dibenzyl-3(S)-amino-1,2(S)-epoxy-4-phenylbutane (388.5 g, 1.13 mol) in isopropanol (2.7 L) (or ethyl acetate) was added isobutylamine (1.7 kgm, 23.1 mol) over 2 min. The temperature increased from 25° C. and to 30° C. The solution was heated to 82° C. and stirred at this temperature for 1.5 h. The warm solution was concentrated under reduced pressure at 65° C., The brown oil residue was transferred to a 3-L flask and dried in vacuo (0.8 mm Hg) for 16 h to give 450 g of 3S- N,N-bis(phenylmethyl)amino-4-phenylbutan-2R-ol as a crude oil.
An analytical sample of the desired major diastereomeric product was obtained by purifying a small sample of crude product by silica gel chromatography (40% ethyl acetate/hexane). Tlc analysis: silica gel, 40% ethyl acetate/hexane; Rf=0.28; HPLC analysis: ultrasphere ODS column, 25% triethylamino-/phosphate buffer pH 3-acetonitrile, flow rate 1 mL/min, UV detector; retention time 7.49 min.; HRMS Calcd for C 28 H 27 N 2 O (M+1) 417.616, found 417.2887. An analytical sample of the minor diastereomeric product, 3S- N,N-bis(phenylmethyl)amino!1-(2-methylpropyl)amino-4-phenylbutan-2S-ol was also obtained by purifying a small sample of crude product by silica gel chromatography (40% ethyl acetate/hexane).
EXAMPLE 5
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine.oxalic acid salt
To a solution of oxalic acid (8.08 g, 89.72 mmol) in methanol (76 mL) was added a solution of crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol {39.68 g, which contains about 25.44 g (61.06 mmol) of 3(S),2(R) isomer and about 4.49 g (10.78 mmol) of 3(S),2(S) isomer} in ethyl acetate (90 mL) over 15 minutes. The mixture was stirred at room temperature for about 2 hours. Solid was isolated by filtration, washed with ethyl acetate (2×20 mL) and dried in vacuo for about 1 hour to yield 21.86 g (70.7% isomer recovery) of 97% diastereomerically pure salt (based on HPLC peak areas). HPLC analysis: Vydec-peptide/protein C18 column, UV detector 254 nm, flow rate 2 mL/min., gradient {A=0.05% trifluoroacetic acid in water, B=0.05% trifluoroacetic acid in acetonitrile, 0 min. 75% A/25% B, 30 min. 10% A/90% B, 35 min. 10% A/90% B, 37 min. 75% A/25% B}; Retention time 10.68 min. (3(S),2(R) isomer) and 9.73 min. (3(S),2(S) isomer). Mp=174.99° C.; Microanalysis: Calc.: C 71.05%, H 7.50%, N 5.53%; Found: C 71.71%, H 7.75%, N 5.39%.
Alternatively, oxalic acid dihydrate (119 g, 0.94 mole) was added to a 5000 mL round bottom flask fitted with a mechanical stirrer and a dropping funnel. Methanol (1000 ml) was added and the mixture stirred until dissolution was complete. A solution of crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl) amino-4-phenylbutan-2(R)-ol in ethyl acetate (1800 ml, 0.212 g amino alcohol isomers/mL, 0.9160 moles) was added over a twenty minute period. The mixture was stirred for 18 hours and the solid product was isolated by centrifugation in six portions at 400 G. Each portion was washed with 125 mL of ethyl acetate. The salt was then collected and dried overnight at 1 torr to yield 336.3 g of product (71% based upon total amino alcohol). HPLC/MS (electrospray) was consistent with the desired product (m/z 417 M+H! + ).
Alternatively, crude 3(S)- N,N-bis(phenylmethyl) amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol (5 g) was dissolved in methyl-tert-butylether (MTBE) (10 mL) and oxalic acid (1 g) in methanol (4 mL) was added. The mixture was stirred for about 2 hours. The resulting solid was filtered, washed with cold MTBE and dried to yield 2.1 g of white solid of about 98.9% diastereomerically pure (based on HPLC peak areas).
EXAMPLE 6
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine.acetic acid salt
To a solution of crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol in methyl-tert-butylether (MTBE) (45 mL, 1.1 g amino alcohol isomers/mL) was added acetic acid (6.9 mL) dropwise. The mixture was stirred for about 1 hour at room temperature. The solvent was removed in vacuo to yield a brown oil about 85% diastereomerically pure product (based on HPLC peak areas). The brown oil was crystallized as follows: 0.2 g of the oil was dissolved in the first solvent with heat to obtain a clear solution, the second solvent was added until the solution became cloudy, the mixture was heated again to clarity, seeded with about 99% diastereomerically pure product, cooled to room temperature and then stored in a refrigerator overnight. The crystals were filtered, washed with the second solvent and dried. The diastereomeric purity of the crystals was calculated from the HPLC peak areas. The results are shown in Table 1.
TABLE 1______________________________________ Diastereo-First Second Solvent Recovery mericSolvent Solvent Ratio Weight (g) Purity (%)______________________________________MTBE Heptane 1:10 0.13 93.3MTBE Hexane 1:10 0.03 99.6Methanol Water 1:1.5 0.05 99.5Toluene Heptane 1:10 0.14 98.7Toluene Hexane 1:10 0.10 99.7______________________________________
Alternatively, crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol (50.0 g, which contains about 30.06 g (76.95 mmol) of 3(S),2(R) isomer and about 5.66 g (13.58 mmol) of 3(S),2(S) isomer} was dissolved in methyl-tert-butylether (45.0 mL). To this solution was added acetic acid (6.90 mL, 120.6 mmol) over a period of about 10 min. The mixture was stirred at room temperature for about 1 hour and concentrated under reduced pressure. The oily residue was purified by recrystallization from methyl-tert-butylether (32 mL) and heptane (320 mL). Solid was isolated by filtration, washed with cold heptane and dried in vacuo for about 1 hour to afford 21.34 g (58.2% isomer recovery) of 96% diastereomerically pure monoacetic acid salt (based on HPLC peak areas). Mp=105°-106° C.; Microanalysis: Calc.: C 75.53%, H 8.39%, N 5.87%; Found: C 75.05%, H 8.75%, N 5.71%.
EXAMPLE 7
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine.L-tartaric acid salt
Crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol (10.48 g, which contains about 6.72 g (16.13 mmol) of 3(S),2(R) isomer and about 1.19 g (2.85 mmol) of 3(S),2(S) isomer} was dissolved in tetrahydrofuran (10.0 mL). To this solution was added a solution of L-tartaric acid (2.85 g, 19 mmol) in methanol (5.0 mL) over a period of about 5 min. The mixture was stirred at room temperature for about 10 min. and concentrated under reduced pressure. methyl-tert-butylether (20.0 mL) was added to the oily residue and the mixture was stirred at room temperature for about 1 hour. Solid was isolated by filtration to afford 7.50 g of crude salt. The crude salt was purified by recrystallization from ethyl acetate and heptane at room temperature to yield 4.13 g (45.2% isomer recovery) of 95% diastereomerically pure L-tartaric acid salt (based on HPLC peak areas). Microanalysis: Calc.: C 67.76%, H 7.41%, N 4.94%; Found: C 70.06% H 7.47%, N 5.07%.
EXAMPLE 8
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine.dihydrochloric acid salt
Crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol (10.0 g, which contains about 6.41 g (15.39 mmol) of 3(S),2(R) isomer and about 1.13 g (2.72 mmol) of 3(S),2(S) isomer} was dissolved in tetrahydrofuran (20.0 mL) To this solution was added hydrochloric acid (20 mL, 6.0N) over a period of about 5 min. The mixture was stirred at room temperature for about 1 hour and concentrated under reduced pressure. The residue was recrystallized from ethanol at 0° C. to yield 3.20 g (42.7% isomer recovery) of 98% diastereomerically pure dihydrochloric acid salt (based on HPLC peak areas). Microanalysis: Calc.: C 68.64%, H 7.76%, N 5.72%; Found: C 68.79%, H 8.07%, N 5.55%.
EXAMPLE 9
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine.toluenesulfonic acid salt
Crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol (5.0 g, which contains about 3.18 g (7.63 mmol) of 3(S),2(R) isomer and about 0.56 g (1.35 mmol) of 3(S),2(S) isomer) was dissolved in methyl-tert-butylether (10.0 mL). To this solution was added a solution of toluenesulfonic acid (2.28 g, 12 mmol) in methyl-tert-butylether (2.0 mL) and methanol (2.0 mL) over a period of about 5 min. The mixture was stirred at room temperature for about 2 hours and concentrated under reduced pressure. The residue was recrystallized from methyl-tert-butylether and heptane at 0° C., filtered, washed with cold heptane and dried in vacuo to yield 1.85 g (40.0% isomer recovery) of 97% diastereomerically pure monotoluenesulfonic acid salt (based on HPLC peak areas).
EXAMPLE 10
N- 3(S)- N,N-bis(phenylmethyl)amino!-2(R)-hydroxy-4-phenylbutyl!-N-isobutylamine.methanesulfonic acid salt
Crude 3(S)- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2(R)-ol (10.68 g, which contains about 6.85 g (16.44 mmol) of 3(S),2(R) isomer and about 1.21 g (2.90 mmol) of 3(S),2(S) isomer) was dissolved in tetrahydrofuran (10.0 mL). To this solution was added methanesulfonic acid (1.25 mL, 19.26 mmol). The mixture was stirred at room temperature for about 2 hours and concentrated under reduced pressure. The oily residue was recrystallized from methanol and water at 0° C., filtered, washed with cold methanol/water (1:4) and dried in vacuo to yield 2.40 g (28.5% isomer recovery) of 98% diastereomerically pure monomethanesulfonic acid salt (based on HPLC peak areas).
EXAMPLE 11
3S- N,N-Bis(phenylmethyl)amino!-1-(3-methylbutyl)amino-4-phenylbutan-2R-ol
Example 4 was followed using isoamylamine instead of isobutylamine to prepare 3S- N,N-Bis(phenylmethyl)amino!-1-(3-methylbutyl)amino-4-phenylbutan-2R-ol and 3S- N,N -Bis (phenylmethyl)amino!-1-(3-methylbutyl)amino-4-phenylbutan-2S-ol in comparable yields to that of Example 4. The crude amine was used in the next step without further purification.
EXAMPLE 12
N- 3S- N,N-Bis(phenylmethyl)amino!-2R-hydroxy-4-phenyl butyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
A solution of the crude 3S- N,N-bis(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol (446.0 g, 1.1 mol) from Example 4 in tetrahydrofuran (6 L) (or ethyl acetate) was cooled to 8° C. t-Butyl isocyanate (109.5 g, 1.1 mol) was then added to the solution of the amine from an addition funnel at a rate that maintained the temperature between 10°-12° C. (addition time was about 10 min). The external cooling was stopped and the reaction was warmed to 18° C. after 30 min. The solution was transferred directly from the reactor to a rotary evaporator flask (10 L) through a teflon tube using vacuum and then concentrated. The flask was heated in a 50° C. water bath during the 2 hours required for the distillation of the solvent The brown residue was dissolved in ethyl acetate (3 L), washed with 5% aq citric acid solution (1×1.2 L), water (2×500 mL), brine (1×400 mL), dried over magnesium sulfate (200 g) and filtered. The volume of product solution was reduced to 671 mL over 2 h on a rotary evaporator at 50° C. The concentrate was stirred and diluted with 1.6 L of hexane. The mixture was cooled to 12° C. and stirred for 15 hours. The product crystals were isolated by filtration, washed with 10% ethyl acetate/hexane (1×500 mL), hexane (1×200 mL) and dried in vacuo (2 mm) at 50° C. for 1 hour to give 248 g of N- 3S- N,N-bis-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)-urea. The mother liquor and washes were combined and concentrated on a rotary evaporator to give 270 g of a brown oil. This material was dissolved in ethyl acetate (140 mL) at 50° C. and diluted with hexane (280 mL) and seeded with crystals of the first crop product (20 mg). The mixture was cooled in an ice bath and stirred for 1 h. The solid was isolated by filtration, washed with 10% ethyl acetate/hexane (1×200 mL) and dried in vacuo (2 mm) at 50° C. for 1 h to give 55.7 g of 11 as the second crop (49% overall yield). Mp 126° C.; α!D25=-59.0° (c=1.0, CH2Cl2), TLC: Rf 0.31 (silica gel, 25% ethyl acetate/hexane).
An analytical sample of the minor diastereomer, N- 3S- N,N-bis(phenylmethyl)amino!-2S-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea was isolated by silica-gel chromatography (10-15% ethyl acetate/hexane) in an earlier experiment and characterized.
EXAMPLE 13
N- 3S- N,N-Bis(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea
The crude product from Example 11 was reacted with t-butylisocyanate following the method of Example 12 to prepare N- 3S- N,N-Bis(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea and N- 3S- N,N-Bis(phenylmethyl)amino!-2S-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea in comparable yields to that of Example 12.
EXAMPLE 14
N- 3S-Amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
N- 3S- N,N-Bis(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea (125.77 g, 0.244 mol) from Example 12 was dissolved in ethanol (1.5 L) (or methanol) and 20% palladium hydroxide on carbon (18.87 g) (or 4% palladium on carbon) was added to the solution under nitrogen. The mixture was stirred at ambient temperature under a hydrogen atmosphere at 60 psi for approximately 8 hours. The catalyst was removed by filtration and the filtrate was concentrated to give 85 g of N- 3S-Amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N'-(2-methylpropyl)urea as a colorless oil.
EXAMPLE 15
N- 3S-Amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl) -N-(3-methylbutyl)urea
N- 3S- N,N-Bis(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea from Example 13 was hydrogenated following the method of Example 14 to prepare N- 3S-Amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea in comparable yields to Example 14.
EXAMPLE 16
N-benzyl-L-phenylalaninol
METHOD 1
L-Phenylalaninol (89.51 g, 0.592 moles) was dissolved in 375 mL of methanol under inert atmosphere, 35.52 g (0.592 moles) of glacial acetic acid and 50 mL of methanol was added followed by a solution of 62.83 g (0.592 moles) of benzaldehyde in 100 mL of methanol. The mixture was cooled to approximately 15° C. and a solution of 134.6 g (2.14 moles) of sodium cyanoborohydride in 700 mL of methanol was added in approximately 40 minutes, keeping the temperature between 15° C. and 25° C. The mixture was stirred at room temperature for 18 hours. The mixture was concentrated under reduced pressure and partitioned between 1 L of 2M ammonium hydroxide solution and 2 L of ether. The ether layer was washed with 1 L of 1M ammonium hydroxide solution, twice with 500 mL water, 500 mL of brine and dried over magnesium sulfate for 1 hour. The ether layer was filtered, concentrated under reduced pressure and the crude solid product was recrystallized from 110 mL of ethyl acetate and 1.3 L of hexane to give 115 g (81% yield) of N-benzyl-L-phenylalaninol as a white solid.
METHOD 2
L-Phenylalaninol (5 g, 33 mmoles) and 3.59 g (33.83 mmoles) of benzaldehyde were dissolved in 55 mL of 3A ethanol under inert atmosphere in a Parr shaker and the mixture was warmed to 60° C. for 2.7 hours. The mixture was cooled to approximately 25° C. and 0.99 g of 5% platinum on carbon was added and the mixture was hydrogenated at 60 psi of hydrogen and 40° C. for 10 hours. The catalyst was filtered off, the product was concentrated under reduced pressure and the crude solid product was recrystallized from 150 mL of heptane to give 3.83 g (48% yield) of N-benzyl-L-phenylalaninol as a white solid.
EXAMPLE 17
N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninol
N-benzyl-L-phenylalaninol (2.9 g, 12 mmoles) from Example 16 was dissolved in 3 mL of triethylamine and 27 mL of methanol and 5.25 g (24.1 mmoles) of di-tert-butyl dicarbonate was added. The mixture was warmed to 60° C. for 35 minutes and concentrated under reduced pressure. The residue was dissolved in 150 mL of ethyl acetate and washed twice with 10 mL of cold (0°-5° C.), dilute hydrochloric acid (pH 2.5 to 3), 15 mL of water, 10 mL of brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product oil was purified by silica gel chromatography (ethyl acetate: hexane, 12:3 as eluting solvent) to give 3.98 g (97% yield) of colorless oil.
EXAMPLE 18
N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninal
METHOD 1
To a solution of 0.32 g (0.94 mmoles) of N-(t-Butoxycarbonyl) -N-benzyl-L-phenylalaninol from Example 17 in 2.8 mL of toluene was added 2.4 mg (0.015 mmoles) of 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical (TEMPO), 0.1 g (0.97 mmoles) of sodium bromide, 2.8 mL of ethyl acetate and 0.34 mL of water. The mixture was cooled to 0° C. and an aqueous solution of 4.2 mL of 5% household bleach containing 0.23 g (3.0 mL, 20738 mmoles) of sodium bicarbonate was added slowly over 30 minutes. The mixture was stirred at 0° C. for 10 minutes. Three more additions (0.4 mL each) of bleach was added followed by stirring for 10 minutes after each addition to consume all the stating material. The two phase mixture was allowed to separate. The aqueous layer was extracted twice with 8 mL of toluene. The combined organic layer was washed with 1.25 mL of a solution containing 0.075 g of potassium iodide, sodium bisulfate(0.125 g) and water(1.1 mL), 1.25 mL of 10% aqueous sodium thiosulfate solution, 1.25 mL of pH 7 phosphate buffer and 1.5 mL of brine solution. The organic solution was dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 0.32 g (100% yield) of N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninal.
METHOD 2
To a solution of 2.38 g (6.98 mmoles) of N-(t-butoxycarbonyl)-N-benzyl-L-phenylalaninol from Example 17 in 3.8 mL (27.2 mmoles) of triethylamine at 10° C. was added a solution of 4.33 g (27.2 mmoles) of sulfur trioxide pyridine complex in 17 mL of dimethyl sulfoxide. The mixture was warmed to room temperature and stirred for one hour. Water (16 mL) was added and the mixture was extracted with 20 mL of ethyl acetate. The organic layer was washed with 20 mL of 5% citric acid, 20 mL of water, 20 mL of brine, dried over magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to give 2.37 g (100% yield) of N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninal.
EXAMPLE 19
N,αS-Bis(phenylmethyl)-N- (t-butoxycarbonyl)-2S-oxiranemethanamine
METHOD 1
A solution of 2.5 g (7.37 mmoles) of N-(t-butoxycarbonyl)-N-benzyl-L-phenylalaninal from Example 18 and 0.72 mL of chloroiodomethane in 35 mL of THF was cooled to -78° C. A 4.64 mL of a solution of n-butyllithium (1.6M in hexane, 7.42 mmoles) was added slowly, keeping the temperature below -70° C. The mixture was stirred for 10 minutes between -70° to -75° C. Two additional portions of 0.22 mL of chloroiodomethane and 1.4 mL of n-butyllithium was added sequentially and the mixture was stirred for 10 minutes between -70° to -75° C. after each addition. Four additional portions of 0.11 mL of chloroiodomethane and 0.7 mL of n-butyllithium was added sequentially and the mixture was stirred for 10 minutes between -70° to -75° C. after each addition. The mixture was warmed to room temperature for 3.5 hours. The product was quenched at below 5° C. with 24 mL of ice-cold water. The biphasic layers were separated and the aqueous layer was extracted twice with 30 mL of ethyl acetate. The combined organic layers was washed three times with 10 mL water, then with 10 mL brine, dried over sodium sulfate, filtered and concentrated under reduced pressure to give 2.8 g of a yellow crude oil. This crude oil (>100% yield) is a mixture of the diastereomeric epoxides N,αS-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2S-oxiranemethanamine and N,αS-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2R-oxiranemethanamine. The crude mixture is used directly in the next step without purification.
METHOD 2
To a suspension of 2.92 g (13.28 mmoles) of trimethylsulfoxonium iodide in 45 mL of acetonitrile was added 1.49 g (13.28 mmoles) of potassium t-butoxide. A solution of 3.0 g (8.85 mmoles) of N-(t-butoxycarbonyl) -N-benzyl-L-phenylalaninal from Example 18 in 18 mL of acetonitrile was added and the mixture was stirred at room temperature for one hour. The mixture was diluted with 150 mL of water and extracted twice with 200 mL of ethyl acetate. The organic layers were combined and washed with 100 mL water, 50 mL brine, dried over sodium sulfate, filtered and concentrated under reduced pressure to give 3.0 g of a yellow crude oil. The crude product was purified by silica gel chromatography (ethyl acetate/hexane: 1:8 as eluting solvent) to give 1.02 g (32.7% yield) of a mixture of the two diastereomers N,αS-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2S-oxiranemethanamine and N,αS-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2R-oxiranemethanamine.
METHOD 3
To a suspension of 0.90 g (4.42 mmoles) of trimethylsulfonium iodide in 18 mL of acetonitrile was added 0.495 g (4.42 mmoles) of potassium t-butoxide. A solution of 1.0 g (2.95 mmoles) of N-(t-butoxycarbonyl) -N-benzyl-L-phenylalaninal from Example 18 in 7 mL of acetonitrile was added and the mixture was stirred at room temperature for one hour. The mixture was diluted with 80 mL of water and extracted twice with 80 mL of ethyl acetate. The organic layers were combined and washed with 100 mL water, 30 mL brine, dried over sodium sulfate, filtered and concentrated under reduced pressure to give 1.04 g of a yellow crude oil. The crude product was a mixture of the two diastereomers N,60 S-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2S-oxiranemethanamine and N,αS-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2R-oxiranemethanamine.
EXAMPLE 20
3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol
To a solution of 500 mg (1.42 mmoles) of the crude epoxide from Example 19 in 0.98 mL of isopropanol was added 0.71 mL (7.14 mmoles) of isobutylamine. The mixture was warmed to reflux at 85° C. to 90° C. for 1.5 hours. The mixture was concentrated under reduced pressure and the product oil was purified by silica gel chromatography (chloroform:methanol, 100:6 as eluting solvents) to give 330 mg of 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol as a colorless oil (54.5% yield). 3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2S-ol was also isolated. When purified N,αS-bis(phenylmethyl)-N-(t-butoxycarbonyl)-2s-oxiranemethanamine was used as starting material, 3s- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol was isolated after purification by chromatography in an 86% yield.
EXAMPLE 21
N- 3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
To a solution of 309 mg (0.7265 mmoles) of 3s- N -(t-butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol from Example 20 in 5 mL of THF was added 0.174 mL(l.5 mmoles) of t-butylisocyanate. The mixture was stirred at room temperature for 1.5 hours The product was concentrated under reduced pressure to give 350 mg (92% yield) of a white solid crude product. The crude product was purified by silica gel chromatography (ethyl acetate/hexane: 1:4 as eluting solvents) to give 324 mg of N- 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea as a white solid (85.3% yield).
EXAMPLE 22
3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-2S -hydroxy-4-phenylbutyronitrile
A solution of 7.0 g (20.65 mmoles) of N-(t-butoxycarbonyl)-N-benzyl-L-phenylalaninal from Example 18 in 125 mL of THF was cooled to -5° C. A solution of 12.96 g of sodium bisulfite in 68 mL of water was added over 40 minutes, keeping the temperature below 5° C. The mixture was stirred for 3 hours at 0° to 5° C. An additional 1.4 g of sodium bisulfite was added and the mixture was stirred for another two hours. Sodium cyanide (3.3 g, 82.56 mmoles) was added to the bisulfite product at 0° to 5° C. and the mixture was stirred at room temperature for 16 hours. The biphasic mixture was extracted with 150 mL of ethyl acetate. The aqueous layer was extracted twice each with 100 mL of ethyl acetate. The combined organic layers was washed twice with 30 mL water, twice with 25 mL brine, dried over sodium sulfate, filtered and concentrated under reduced pressure to give 7.5 g (100% crude yield of both diastereomers) of crude oil. The crude oil was purified by silica gel chromatography (ethyl acetate: hexane, 1:4 as eluting solvents) to give 5.725 g (76% yield) of 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-2S-hydroxy-4-phenylbutyronitrile as the major later eluting diastereomer and 0.73 g (9.6% yield) of 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyronitrile as the minor diastereomer. The combined yields of both isomers of cyanohydrins is 85.6% yield.
EXAMPLE 23
3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-1-amino-4-phenylbutan-2R-ol
To a solution of 205.5 mg (0.56 mmoles) of 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-2S-hydroxy-4-phenylbutyronitrile from Example 22 in 4 mL of THF was added 2.4 mL of a solution of borane in THF (1.0M, 4 mmoles). The mixture was stirred at room temperature for 30 minutes. An additional 1.4 mL of borane in THF was added and the mixture was stirred for another 30 minutes. The mixture was cooled to 0° C. and 2.0 mL of cold(0°-5° C.) water was added slowly. The mixture was warmed to room temperature and stirred for 30 minutes. The product was extracted twice with 30 mL of ethyl acetate. The organic layers were combined and washed with 4 mL water, 4 mL brine, dried over sodium sulfate, filtered and concentrated under reduced pressure to give 200 mg of 3S - N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-1-amino-4-phenylbutan-2R-ol as a white solid (96.4% yield).
EXAMPLE 24
3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol
To a solution of 2.41 g (6.522 mmoles) of 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-1-amino-4-phenylbutan-2R-ol from Example 23 in 40 mL of methanol was added 0.592 mL (6.522 mmoles) of isobutyraldehyde and 0.373 mL (6.522 mmoles) of acetic acid. The mixture was stirred for 10 minutes. Sodium cyanoborohydride (1.639 g, 26 mmoles) was added and the mixture was stirred for 16 hours at room temperature. The product mixture was concentrated under reduced pressure and partitioned between 150 mL of ethyl acetate and 50 mL of 1.5M ammonium hydroxide. The organic layer was washed twice with 20 mL water, twice with 20 mL brine, dried over sodium sulfate, filtered and concentrated to an yellow oil. The crude product was purified by silica gel chromatography (chloroform: methanol, 100:6 as eluting solvents) to give 2.326 g of 3S- N-(t-butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol as a colorless oil (88.8% yield).
EXAMPLE 25
N- 3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
To a solution of 309 mg (0.7265 mmoles) of 3S- N-(t -butoxycarbonyl)-N-(phenylmethyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol from Example 24 in 5 mL of THF was added 0.174 mL(1.5 mmoles) of t-butylisocyanate. The mixture was stirred at room temperature for 1.5 hours. The product was concentrated under reduced pressure to give 350 mg (92% yield) of a white solid crude product. The crude product was purified by silica gel chromatography (ethyl acetate/hexane: 1:4 as eluting solvents) to give 324 mg of N- 3S- N-(t -butoxycarbonyl)-N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea as a white solid (85.3% yield). cl EXAMPLE 26
N- 3S- N-(Phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
To a solution of 210 mg (0.4 mmoles) of N- 3S- N-(t-Butoxycarbonyl)-N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea from Example 25 in 5.0 mL of THF was added 5 mL of 4N hydrochloric acid. The mixture was stirred at room temperature for two hours. The solvents were removed under reduced pressure to give 200 mg (100%) of N- 3S- N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea as a white solid.
EXAMPLE 27
N- 3S-Amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
To a solution of 200 mg (0.433 mmoles) of N- 3S- N-(phenylmethyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea from Example 26 in 7 mL of 3A ethanol was added 0.05 g of 20% palladium on carbon. The mixture was hydrogenated at 40° C. for 1.8 hours at 5 psi followed by hydrogenation at 60 psi at room temperature for 22 hours. The catalyst was filtered and the solvent and by-product were removed under reduced pressure to give 150 mg (93.4% yield) of N- 3S-amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea as a white solid.
EXAMPLE 28
3S-(N-t-Butoxycarbonyl)amino-4-phenylbutan-1,2R-diol
To a solution of 1 g (3.39 mmoles) of 2S-(N-t -butoxycarbonyl)amino-1S-hydroxy-3-phenylbutanoic acid (commercially available from Nippon Kayaku, Japan) in 50 mL of THF at 0° C. was added 50 mL of borane-THF complex (liquid, 1.0M in THF), keeping the temperatures below 5° C. The reaction mixture was warmed to room temperature and stirred for 16 hours. The mixture was cooled to 0 ° C. and 20 mL of water was added slowly to destroy the excess BH 3 and to quench the product mixture, keeping the temperature below 12° C. The quenched mixture was stirred for 20 minutes and concentrated under reduced pressure. The product mixture was extracted three times with 60 mL of ethyl acetate. The organic layers were combined and washed with 20 mL of water, 25 mL of saturated sodium chloride solution and concentrated under reduced pressure to give 1.1 g of crude oil. The crude product was purified by silica gel chromatography (chloroform/methanol, 10:6 as eluting solvents) to give 900 mg (94.4% yield) of 3S-(N-t-butoxycarbonyl)amino-4-phenylbutan-1,2R-diol as a white solid.
EXAMPLE 29
3S-(N-t-Butoxycarbonyl)amino-2R-hydroxy-4-phenylbut-1-yl Toluenesulfonate
To a solution of 744.8 mg (2.65 mmoles) of 3S-(N-t-butoxycarbonyl)amino-4-phenylbutan-1,2R-diol from Example 28 in 13 mL of pyridine at 0° C. was added 914 mg of toluenesulfonyl chloride in one portion. The mixture was stirred at 0 ° C. to 5° C. for 5 hours. A mixture of 6.5 mL of ethyl acetate and 15 mL of 5% aqueous sodium bicarbonate solution was added to the reaction mixture and stirred for 5 minutes. The product mixture was extracted three times with 50 mL of ethyl acetate. The organic layers were combined and washed with 15 mL of water, 10 mL of saturated sodium chloride solution and concentrated under reduced pressure to give about 1.1 g of a yellow chunky solid. The crude product was purified by silica gel chromatography (ethyl acetate/hexane 1:3 as eluting solvents) to give 850 mg (74% yield) of 3S-(N-t-butoxycarbonyl)amino-2R-hydroxy-4-phenylbut-1-yl toluenesulfonate as a white solid.
EXAMPLE 30
3S- N-(t-Butoxycarbonyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol
To a solution of 90 mg (0.207 mmoles) of 3S-(N-t-butoxycarbonyl)amino-2R-hydroxy-4-phenylbut-1-yl toluenesulfonate from Example 29 in 0.143 mL of isopropanol and 0.5 mL of toluene was added 0.103 mL (1.034 mmoles) of isobutylamine. The mixture was warmed to 80° to 85° C. and stirred for 1.5 hours. The product mixture was concentrated under reduced pressure at 40° to 50 ° C. and purified by silica gel chromatography (chloroform/methanol, 10:1 as eluting solvents) to give 54.9 mg (76.8% yield) of 3S- N-(t-butoxycarbonyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol as a white solid.
EXAMPLE 31
N- 3S- N-(t-Butoxycarbonyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
To a solution of 0.1732 g (0.516 mmoles) of 3S- N-(t-butoxycarbonyl)amino!-1-(2-methylpropyl)amino-4-phenylbutan-2R-ol from Example 30 in 5 mL of ethyl acetate at 0° C. was added 1.62 mL (12.77 mmoles) of t-butylisocyanate and the mixture was stirred for one hour. The product was concentrated under reduced pressure and purified by silica gel chromatography (chloroform/methanol, 100:1.5 as eluting solvents) to give 96 mg (42.9% yield) of N- 3S- N-(t-butoxycarbonyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea as a white solid.
EXAMPLE 32
N- 3S-amino-2R-hydroxy-4-phenylburyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea
To a solution of 10 mg (0.023 mmoles) of N- 3S- N-(t-butoxycarbonyl)amino!-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea from Example 31 in 1 mL of methanol at 0° C. was added 1.05 mL of a 4M hydrogen chloride in methanol and the mixture was stirred at room temperature for 45 minutes. The product was concentrated under reduced pressure. The residue was dissolved 5 mL of methanol and concentrated under reduced pressure. This operation was repeated three times to remove water form the product, after which 8.09 mg (95.2% yield) of N- 3S-amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(2-methylpropyl)urea hydrochloride salt was obtained as a white solid.
EXAMPLE 33
3S-(N,N-Dibenzyl)amino-2S-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether
To a solution of 24.33 g (73.86 mmol) of 2S-(N,N-dibenzyl)amino-3-phenylpropanal in 740 mL of anhydrous methylene chloride at -20° C. under a nitrogen atmosphere, was added 11.8 mL (8.8 g, 88.6 mmol) of trimethylsilylcyanide, then 19.96 g (88.6 mmol) of anhydrous zinc bromide. After 4 hours at -15° C., and 18 hours at room temperature, the solvent was removed under reduced pressure, ethyl acetate was added, washed with water, brine, dried over magnesium sulfate, filtered and concentrated to afford 31.3 g of a brown oil, which was identified as a 95:5 mixture of 3S-(N,N-dibenzyl)amino-2S-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether, m/e=429(M+H) and 3S-(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether, respectively.
EXAMPLE 34
3S-(N,N-Dibenzyl)amino-2S-hydroxy-4-phenylbutyronitrile
A solution of 10.4 g (24.3 mmol) of the crude 95:5 mixture of 3S-(N,N-dibenzyl)amino-2S-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether, and 3S-(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether from Example 33 in 40 mL of methanol, was added to 220 mL of 1N hydrochloric acid with vigorous stirring. The resulting solid was collected, dissolved in ethyl acetate, washed with aqueous sodium bicarbonate, brine, dried over anhydrous magnesium sulfate, filtered and concentrated to afford 8.04 g of crude product. This was recrystallized from ethyl acetate and hexane to afford pure 3S-(N,N-dibenzyl) amino-2S-hydroxy-4-phenylbutyronitrile, m/e=357 (M+H).
EXAMPLE 35
3S-(N,N-Dibenzyl)amino-2R-hydroxy-4-phenylbutylamine
METHOD 1
A solution of 20.3 g (47.3 mmol) of the crude 95:5 mixture of 3S-(N,N-dibenzyl)amino-2S-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether, and 3S-(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether from Example 34 in 20 mL of anhydrous diethyl ether, was added to 71 mL (71 mmol) of a 1M solution of lithium aluminum hydride in diethyl ether at reflux. After the addition, the reaction was refluxed for 1 hour, cooled to 0° C., and quenched by the careful addition of 2.7 mL of water, 2.7 mL of 15% aqueous sodium hydroxide, and 8.1 mL of water. The resulting solids were removed by filtration and the filtrate washed with water, brine, dried over magnesium sulfate, filtered and concentrated to afford 13.8 g of crude material, which was recrystallized from tetrahydrofuran and isooctane to afford 10.6 g of 3S -(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutylamine, Mp=46°-49° C., m/e=361 (M+H), which was contaminated by approximately 2% of 3S-(N,N-dibenzyl)amino-2S-hydroxy-4-phenylbutylamine.
METHOD 2
To 15.6 mL (60.4 mmol) of 70% sodium bis(methoxyethoxy)aluminum hydride in toluene, was added 15mL of anhydrous toluene, and then after cooling to 0° C., a solution of 20.0 g (46 mmol) of the crude 95:5 mixture of 3S-(N,N-dibenzyl)amino-2S-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether, and 3S-(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutyronitrile, O-trimethylsilyl ether from Example 34 in 10 mL of anhydrous toluene, at a rate so as to maintain the temperature below 15° C. After 2.5 hours at room temperature, the reaction was quenched by the careful addition of 200 mL of 5% aqueous sodium hydroxide. The solution was diluted with ethyl acetate, washed with 5% sodium hydroxide, sodium tartrate solution, brine, dried over magnesium sulfate, filtered and concentrated to afford 16.6 g of crude product, which was assayed by HPLC and shown to contain 87% of 3S-(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutylamine.
EXAMPLE 36
N- 3S-(N,N-Dibenzyl)amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea
Step 1
To a solution of 1.0 g (2.77 mmol) of 3S-(N,N-dibenzyl)amino-2R-hydroxy-4-phenylbutylamine from Example 35 in 4.6 mL of ethanol, was added 0.3 mL (0.24 g, 2.77 mmol) of isovaleraldehyde. After 1 hour at room temperature, the ethanol was removed under reduced pressure, 4 mL of ethyl acetate was added and the solution purged with nitrogen. To the solution was added 360 mg of 5% platinum on carbon catalyst, the solution purged with 40 psig of hydrogen and then maintained under 40 psig of hydrogen for 20 hours. The solution was purged with nitrogen, the catalyst removed by filtration and the solvent removed under reduced pressure to afford 473 mg of the crude product.
Step 2
The crude product from Step A was directly dissolved in 5.4 mL of ethyl acetate and 109 mg (1.1 mmol) of tertiary-butyl isocyanate was added. After 1 hour at room temperature, the solution was washed with 5% citric acid, brine, dried over magnesium sulfate, filtered and concentrated to afford 470 mg of crude product. The crude product was recrystallized from ethyl acetate and isooctane to afford 160 mg of N- 3S-(N,N-Dibenzyl)amino-2R-hydroxy-4-phenylbutyl!-N'-(1,1-dimethylethyl)-N-(3-methylbutyl)urea, Mp=120.4°-121.7° C., m/e=530 (M+H).
From the foregoing detailed description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various uses and conditions.
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Chiral hydroxyethylamine, hydroxyethylurea or hydroxyethylsulfonamide isostere containing retroviral protease and renin inhibitors can be prepared by multi-step syntheses that utilize key chiral amine intermediates. This invention is a cost effective method of obtaining such key chiral amine intermediates enantiomerically, diastereomerically and chemically pure. The method is suitable for large scale (multikilogram) productions. This invention also encompasses organic acid and inorganic acid salts of the amine intermediates.
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This is a division, of application Ser. No. 367,203, filed Apr. 12, 1982, now U.S. Pat No. 4,421,818.
TECHNICAL FIELD
The present invention relates to a patterned, nonwoven, articulated fabric comprised of interlocking synthetic fiber elements and to a process for making said fabric utilizing self-assembling fibers. The basic method comprises the steps of: (a) preparing fiber elements that will pass irreversibly from a substantially straight configuration to a substantially closed ring upon appropriate stimulation, e.g., heating; (b) continuously juxtaposing said fiber elements in a predetermined configuration prior to curling; (c) subjecting said fiber elements to external stimulation to make them curl and interlock with one another in a predetermined pattern; and (d) completing the closure of said substantially continuous interlocked loops by joining the ends thereof to form a permanent structure. The resultant chain-mail type fabric exhibits extremely favorable drape and conformability characteristics.
BACKGROUND ART
Prior art fabrics exhibiting desirable drape and conformability characteristics are most typically produced by weaving or knitting processes. However, the labor of weaving or knitting such prior art fabrics is immense. According to Man-Made Fibers by R. W. Moncrieff, John Wiley & Sons, New York, 1975, there will be about six or seven million yarn intersections in a square yard of an ordinary woven jappe. While the loom makes these fairly efficiently, their number sets a limit to the speed with which fabric can be produced. Somewhat similar considerations apply to knitting. There has, therefore, been a considerable incentive to make fabric by methods which avoided the onerous processes of weaving and knitting fabrics either: (a) from film; (b) from felts; (c) from fibers which are bonded or stuck together with some drysetting adhesive to form a felt-like sheet; or by (d) the preparation of similar felt-like sheets on a rubber or plastic backing, usually for carpets; (e) welding of fibers which soften when heated so that one fiber welds to another; (f) bonding with a latent solvent for the fibers; etc.
While prior art nonwoven fabrics are cheaper and less time consuming to produce than the aforementioned knitted and woven fabrics, they generally do not possess the qualities of a woven fabric. Such qualities as drape, hand, and sometimes strength are lacking, since bonding between fibers restricts freedom of motion.
Accordingly, it is an object of the present invention to produce a nonwoven fabric from synthetic monofilament fibers in the form of a regulated chain-mail type structure.
It is a further object of the present invention to prepare a synthetic monofilament fiber that will pass irreversibly from the configuration of a straight rod to that of a substantially closed ring, upon appropriate stimulation, e.g., a change in the surrounding temperature.
It is a further object of the present invention to provide method and apparatus for continuously juxtaposing said treated fiber segments prior to curling so that they will intertwine appropriately to form the aforesaid chain-mail type of structure upon external stimulation.
It is yet another object of the present invention to provide method and apparatus for completing the closure of the ringed, intertwined synthetic fiber segments, e.g., as by a chemical treatment localized at the cut ends of the fiber.
DISCLOSURE OF THE INVENTION
In a particularly preferred embodiment, the present invention relates to a patterned, nonwoven, articulated fabric comprised of interlocking synthetic fiber elements. A preferred method for producing said articulated fabric comprises the steps of: (a) preparing fiber elements that will pass irreversibly from a substantially straight configuration to that of a substantially closed ring upon appropriate stimulation, e.g., heating; (b) continuously juxtaposing said fiber elements in a predetermined orientation and configuration prior to curling; (c) subjecting said fiber elements to external stimulation to make them curl and interlock with one another in a predetermined pattern; and (d) completing the closure of said substantially continuous interlocked loops by securing the opposing free ends of each loop to one another to increase the strength of and impart permanence to the resultant structure.
In a particularly preferred embodiment of the present invention, assembly of the fiber elements into a chain-mail type network is carried out in a fluid medium. The resultant fabric structure exhibits a regulated pattern as well as high drape and conformability due to the controlled interlocking of the individual fiber elements. As utilized herein, the term "regulated" refers to the highly deterministic non-random quality of formed fabrics of the present invention and the accompanying degree of process control that achieves this end objective. In a particularly preferred embodiment of the present invention, the fiber elements are comprised of nylon monofilaments treated approximately half way through their cross-section with phenol to permit subsequent curling in a predetermined orientation upon the application of heat.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the present invention will be better understood from the following description in which:
FIG. 1 is a simplified schematic illustration of a single filament which has been interlocked with four adjacent filaments;
FIG. 2 is a simplified schematic illustration of a single filament of the type utilized to create the structure illustrated in FIG. 1;
FIG. 2A is a greatly enlarged cross-sectional view taken along section line 2A--2A of FIG. 2;
FIG. 3 is an illustration of the filament shown in FIG. 2 as the curling process is being carried out;
FIG. 4 is a simplified schematic illustration of the manner in which straight filaments of the type shown in FIG. 2 are oriented relative to one another in order to create the interlocking system disclosed in FIG. 1;
FIG. 5 is an illustration of the filaments shown in FIG. 4 after the self-curling process has been initiated; and
FIG. 6 is an illustration generally similar to that of FIG. 5 showing the filaments just prior to closure of the opposing filament ends with one another.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 discloses a single unit pattern taken from a continuous sample of a particularly preferred interlocked chain-mail type fabric 10 of the present invention formed by means of a plurality of self-curling fibers 20 of the present invention. It is of course recognized that a two-dimensional fabric of the present invention can be created utilizing an even more basic unit pattern comprising a first fibrous loop formed by a first fibrous element interlocked with as few as three additional fibrous loops also formed by fibrous elements. It is further recognized that it is not necessary for every fibrous loop within such a fabric be similarly interlocked with three additional fribrous loops. Some such loops may interlock with as few as two additional fibrous loops to create a continuous two-dimensional structure of the aforementioned type.
For purposes of illustration, the single centrally located fibrous element 20 shown in FIG. 1 is interlocked with four peripherally located fibrous elements 20. While it is contemplated that the present invention would be practiced on a macroscopic scale by similarly interlocking said peripheral fibrous elements 20 with one or more similar fibrous elements 20 in whatever pattern is desired in the resultant structure, said additional linkages have not been shown in order to simplify the description of the present invention.
In the condition illustrated in FIG. 1, five discrete synthetic fiber elements 20 have been caused to curl in a predetermined orientation such that their opposing free ends have come into abutting contact with one another, and the opposing free ends of each element have thereafter been secured at joints 30 to form discrete circular links permanently interlocked, but otherwise unbonded to one another.
The basic steps involved in the preparation of a fabric such as that illustrated in FIG. 1 include: (1) preparation of fiber segments that will pass irreversibly from straight lengths to closed rings upon appropriate stimulation, e.g., a change in the temperature or composition of the surrounding medium; (2) continuously juxtaposing said fiber segments prior to curling such that when the fiber segments are subjected to external stimulation they will intertwine and interlock in predetermined fashion; and (3) completing the closure of the ringed, intertwined fiber segments, preferably by a thermal or chemical treatment that is effective only at the cut ends of the fibers. It is of course recognized that for complex patterns of interlocking fiber segments, the juxtaposing and curling steps may be carried out in more than a single stage to avoid collisions which might otherwise occur if all of the fibers utilized in the resultant fabric are caused to undergo simultaneous curling.
The crimping or tendency to curl inherent in natural fibers is a commonly observed phenomenon. Wool is one such naturally crimping fiber. The crimping of synthetic fibers is also known. For example, U.S. Pat. No. 4,172,172 issued to Suzuki et al. on Oct. 23, 1979 discloses a non-patterned, nonwoven fabric composed of synthetic fiber, preferably 100 percent polyester fiber, wherein individual fibers are held together by three-dimensional entanglement into a stabilized sheet form without being subjected to any bonding treatment. The described method for manufacturing a web of the type disclosed in the patent to Suzuki et al. comprises placing on a substantially smooth supporting member a web composed of highly shrinkable synthetic fiber having a potential heat shrinkage of 50% or more, exposing said web to the impact of fine jet streams of water discharged under a pressure of 10-35 kilograms per square centimeter, thereby allowing individual fibers to entangle with one another, thereafter subjecting the web to wet heat treatment at free length conditions to allow the web to shrink by 50% or more in area, drying the web at a temperature at which no change takes place in the shape and internal structure of the individual fibers, and then subjecting the web to heat setting under an applied pressure of 200 grams per square centimeter or more.
A nonwoven web 10 of the present invention differs from the web disclosed in the aforementioned patent to Suzuki et al. in that the resultant web is patterned rather than random. In addition, the opposing free ends of the circular links formed are bonded to one another to provide interlocked rings arranged in a predetermined pattern, but otherwise unadhered to one another.
In particular, the monofilament fibers 20 employed in the practice of the present invention are treated so as to curl in a predetermined orientation in response to an external stimulus. The treated fibers are thereafter placed in a high viscosity fluid medium from which curling is to take place in a regulated, deterministic fashion. Accordingly, nonwoven fabrics of the present invention can be made to exhibit the regulated aspects of woven and knitted fabrics, while being produced with the ease and facility of nonwoven webs. In addition, since the filaments are only interlocked, but not bonded to one another, nonwoven fabrics of the present invention exhibit drape, conformability and strength not achievable in prior art nonwoven webs.
In a particularly preferred embodiment of the present invention, the crimping exhibited by the fibers 20 is caused by temperature or solvent-induced relaxation of a monofilament fiber, the cross-section of which has previously been asymmetrically treated along its length. In a particularly preferred embodiment, an asymmetric phenol treatment of round nylon fibers to cause highly controllable, irreversible, planar curling, which occurs upon heating, is carried out. While not wishing to be bound by the theory of operation, it is believed that the overall mechanism of curling is very similar to that which occurs in a bicomponent metallic strip, such as that used in thermostats.
When the opposing free ends of each fiber are to be permanently joined to one another after the curl-inducing stimulus has been removed, it is important that the curl induced in each fiber be irreversible in nature. As utilized herein, the term "irreversible" shall mean that the curled fiber substantially retains its curled conformation upon removal of the curl-inducing stimulus rather than returning to a substantially straight configuration. However, in embodiments of the present invention wherein the opposing free ends of each fiber are permanently joined to one another either instantaneously upon contact or in the presence of the curl-inducing stimulus, irreversibility upon removal of the curl-inducing stimulus is non-critical. Clearly, once the opposing free ends of each fiber have been permanently joined to one another, the fiber can no longer return to a planar condition when the curl-inducing stimulus is removed, regardless of the irreversibility of the induced curl.
In an exemplary embodiment, the present fiber preparation process may be carried out utilizing 0.35 millimeter diameter monofilament fishing line substantially round in cross-section and comprised of highly oriented Nylon 6, such as is available from E. I. DuPont De Nemours & Company, Inc. of Wilmington, Delaware, under the specification "Stren", ten pound test. The monofilament fishing line is preferably subjected to the following steps: (1) reorient the monofilament to overcome its having been wound on a spool. This may be done by annealing the line under tension, preferably for a period of about 12 hours at a temperature of about 200° F.; (2) wash the monofilament line with heptane to remove the silicone oil typically added in the commercial process for making the line to prevent sticking of the wound fibers; (3) cut the line into predetermined lengths slightly greater than that desired in the finished fibers, e.g., a cut length of slightly in excess of one centimeter; (4) float the discrete cut fibers on a seven percent phenol solution for a period of approximately three seconds to allow for the asymmetric diffusion of phenol approximately half way through the monofilament's cross-section. A methylene blue dye is preferably incorporated in the phenol solution so that the treated portion of the fiber may later be distinguished from the untreated portion; (5) quench the treated fibers in a two percent sodium hydroxide solution; (6) wash the treated and quenched fibers with water; (7) coat the entire external surface of each treated fiber with varnish or any similar material which is substantially impermeable to solutions of phenol by completely immersing said fibers in said phenol-impermeable material to facilitate subsequent bonding of only the fiber ends to one another; (8) provide each of the treated and coated fibers with uncoated end surfaces by cutting off both ends of each fiber to produce individual treated and coated fiber elements of the desired length, e.g., a cut length of approximately one centimeter. It will be appreciated that although the cuts shown in the Drawing Figures are oriented substantially perpendicular to the longitudinal axis of the fiber, parallel cuts may be made at any desired angle to the fiber's axis to increase the available bonding area and to minimize alignment problems between the fiber's free ends after curling; (9) immersing the treated, coated and cut fibers in a second and more concentrated phenol solution, preferably having a strength on the order of about twenty percent, to soften the exposed cut ends of each of the fibers; (10) juxtaposing said fibers in a predetermined orientation in a high viscosity fluid medium such as vaseline; and (11) subjecting said fibers to heat sufficient to cause said fibers to assume a predetermined curled and interlocked conformation with their opposing cut ends substantially in contact with one another and under slight pressure, whereby said opposing ends which have been softened by exposure to said concentrated phenol solution are bonded to one another to form a permanent structure.
As an alternative to the foregoing process, the fibers could be initially cut to the desired finished length, and coating step (7) and secondary end cutting step (8) could be eliminated. In the latter case, only the ends of the treated fibers rather than the entire surface of the fibers would be exposed to the more concentrated phenol solution prior to the juxtaposing and curling operations. This would produce an interlocked fabric structure similar in configuration to that described in conjunction with the process described earlier herein. However, the latter fabric embodiment differs from the former fabric embodiment in that it is comprised of fibers which do not have a phenol impervious coating on their exterior surfaces.
In still another embodiment of the present invention, an adhesive material may be applied to one or both opposing ends of each of the fibers prior to carrying out the juxtaposing and curling operations. This could be via a conventional adhesive or by application of a small amount of nearly any material having a softening point below the temperature required to produce curling of the fibers. The softened material solidifies and serves to permanently bond the opposing free ends of the fibers to one another when the temperature of the curled fibers returns to ambient. One such material suitable for use with nylon fibers of the type described herein is polyethylene wax.
As a result of the assymetric phenol treatment described earlier herein, monofilament fibers 20 of the present invention typically exhibit an untreated portion 22, i.e., that portion which floats above the surface of the phenol solution, and a treated portion 21, i.e., that portion which is immersed in the phenol solution. An exemplary treated fiber 20 is illustrated in FIG. 2. Since the fibers are not caused to rotate during the foregoing treatment, the treated portion 21 of the fiber, which corresponds approximately to half of the fiber's cross-section, extends substantially uniformly along the fiber's length.
It has been demonstrated that substantially straight treated fibers 20 of the present invention may be caused to assume a curled conformation in the direction of the treated portion 21, as generally illustrated in FIG. 3, when placed in vaseline and subjected to an external stimulus, such as a temperature of approximately 200° F. for approximately 15 seconds. While not wishing to be bound by the theory of operation, it is believed that the phenol solution treatment disrupts hydrogen bonds in the drawn and annealed nylon, which is heavily oriented and hydrogen bonded. It is further believed that this disruption of hydrogen bonds only in the areas where said phenol solution is allowed to diffuse causes the molecular chains present in the treated portion 21 of the fiber 20 to revert to a more random coil state. Reversion of the fiber 20 to a coiled state is resisted by the untreated portion 22 of the fiber which remains highly oriented until such time as heat is applied. The heat permits slippage of the molecular chains in the treated portion 21 of the fiber 20, resulting in curling in the direction of the treated portion of the fiber.
Because both the degree and orientation of curl can be determined ahead of time with fibers 20 of the present invention, it is possible to orient the fibers while in a straight configuration such that upon external stimulation, the fibers will be caused to curl and interlock with one another in a predetermined configuration.
While vaseline has been preferred as a fiber retention medium during the fiber juxtaposing and curling operations employed in practicing the present invention, nearly any fluid medium which will not adversely react with the fibers and which exhibits a viscosity high enough to hold the fibers in position at temperatures below the curling temperature, yet low enough that it will not impede curling of the fibers when the curling temperature is reached may be employed with equal facility.
One such arrangement for creating an articulated nonwoven fabric 10 of the type generally disclosed in FIG. 1 is illustrated in FIG. 4. In the arrangement illustrated in FIG. 4, four of the treated monofilament fibers 20 are oriented so as to substantially intersect and form a cross with one another. These particular treated fibers 20 are oriented so that their untreated surfaces 22 are embedded in a substrate of vaseline 50. A fifth treated fiber 20 which forms the central loop illustrated in FIG. 1 is positioned so that it is slightly to the left of the intersection of the remaining fibrous elements 20 and is so oriented that the dividing line between its untreated surface 22 and its treated surface 21 is in a plane substantially perpendicular to the plane of the vaseline substrate 50.
When the treated fibers 20 illustrated in FIG. 4 are subjected to external stimulation, in this case a temperature of approximately 200° F., those fibers with their phenol treated surfaces 21 upwardly oriented from the vaseline substrate 50 are caused to curl out of the vaseline in the direction generally indicated by the arrows of FIG. 5. Meanwhile, the fifth or centrally located treated fiber 20 begins to curl in the direction of its treated portion 21 to form a loop in a plane substantially parallel to that of the vaseline substrate 50.
As the curling process continues, the four treated fiber elements 20 initially having their phenol treated portions 21 upwardly oriented curl out of the plane of the vaseline to form substantially closed rings, as generally shown in FIG. 6. Meanwhile, the fifth treated fiber element 20 having its line of demarcation between the treated portion 21 and the untreated portion 22 of the fiber 20 initially oriented perpendicular to the plane of the vaseline substrate 50 forms an identical circular link which ties the four vertically oriented circular links into interlocking relation with one another.
The heating process is completed when the fiber elements 20 conclude their deformation, i.e., when the opposing free ends of each of the respective elements contact one another.
In the embodiment illustrated in FIGS. 1-6, the exposed cut ends of the fiber elements 20 are unprotected by the phenol-impermeable coating 40 applied to the monofilaments during fiber processing. For purposes of clarity, the phenol-impervious coating 40 which is very thin in relation to the diameter of the fiber 20, is shown only in the cross-sectional view of FIG. 2A. Since the exposed cut ends of the interlocking loops are softened by exposure to a concentrated phenol solution prior to juxtaposing the fibers in the vaseline substrate 50 and initiating the curling process, the softened opposing free ends of each fiber are permanently bonded to one another at joints 30, as generally disclosed in FIG. 1. Because only the exposed cut ends of the fibers 20 are affected by the secondary concentrated phenol treatment, the interlocked continuous rings thus formed remain free to articulate with respect to one another, thus providing outstanding drape and conformability in the resultant nonwoven patterned fabric 10.
While the present invention has been described only in conjunction with a manual process, it is within the scope of the present invention to fully automate the present process, as by continuously treating the monofilament fiber as it is extruded, continuously coating the exterior surfaces of the treated fiber to resist bonding, automatically cutting the coated fiber into discrete predetermined lengths, exposing the cut ends of the fiber to a softening chemical as the fibers are being cut into discrete lengths, automatically applying the coated and treated fibers to one or more sets of vaseline coated combining rolls in a predetermined pattern and in preoriented condition and thereafter subjecting the continuous pattern of preoriented fibers to an elevated temperature sufficient to cause the curling phenomenon to be carried out in the nip between said combining rolls.
It is further recognized that while nylon fibers which have been treated by phenol solution have been disclosed as an exemplary embodiment, other types of fibers could likewise be employed. Furthermore, homogeneous fibers of constant, but irregular cross-section could be extruded to provide an even more pronounced tendency to curl in a predetermined orientation when chemically treated in assymetric fashion, as generally disclosed herein. This would of course necessitate care during the assymetric chemical treatment process to ensure that the fiber's tendency to curl upon external stimulation is enhanced rather than negated. In still other embodiments, bicomponent fibers having dissimilar coefficients of expansion and contraction might also be employed in conjunction with the assymetric chemical treatment to provide fibers exhibiting a highly pronounced tendency to curl in a predetermined orientation upon external stimulation.
While particular, embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It is intended to cover in the appended claims all such modifications that are within the scope of this invention.
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A patterned, nonwoven, articulated fabric exhibiting a substantially uniform texture and comprised of a multiplicity of synthetic fiber elements, the opposing free ends of each of said synthetic fiber elements being joined to one another to form substantially continuous loops, said loops being interconnected to one another in a predetermined pattern. Method for producing said nonwoven fabric using specially prepared fiber elements which curl in a predetermined configuration in response to an external stimulus is also disclosed.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for controlling the flow of fluids through subterranean formations.
It is well-known that subterranean formations comprise layers or zones of different permeabilities. In the recovery of hydrocarbon material such as oil or natural gas from a subterranean reservoir, highly porous or permeable zones often create significant problems.
For example, in enhanced or secondary oil recovery operations such as water or surfactant flooding wherein an aqueous fluid is injected into the formation to drive the hydrocarbon to a producing wellbore, a disproportionately high amount of the injected drive fluid bypasses through zones of high permeability into the producing wellbore without sweeping appreciable amounts of hydrocarbon from the reservoir. This greatly reduces the efficiency of the operation. In addition, excessive amounts of water are recovered along with the hydrocarbon.
Alternatively, water, normally in the form of brine, is commonly native to the formation. The communication of a water-containing strata with a producing wellbore via a highly permeable zone can cause excessive water to be produced along with the hydrocarbon. This results in a high pumping cost and a disposal problem for the recovered water.
Various solutions have been proposed heretofore to control the permeability of subterranean formations. For example, it has been proposed to place a solid plug of a material such as cement within the more permeable zones of the formation. Similarly, suspensions of finely divided solids have been pumped into the formation in an attempt to plug highly permeable zones. Materials employed in such attempts have included organic matter such as ground leather or ground walnut shells and inorganic materials such as clays and finely ground silica. Unfortunately, the use of solid plugs or finely divided solid powders has frequently proved unsuccessful due to the fact that the material fails to plug the zones of high permeability or, conversely, the material indiscriminately and permanently plugs both hydrocarbon bearing zones as well as other zones in the formation, thereby resulting in a permanent loss of the desired hydrocarbon fluid. Moreover, even when the operation is successful, completely plugging portions of the formation does not significantly increase the recovery operation.
Alternatively, it has been proposed to control the permeability of a formation and hence modify the mobility of a fluid through the formation using a viscous fluid pumped into the hydrocarbon-bearing formation. For example, U.S. Pat. No. 3,039,529 describes incorporating a partially hydrolyzed polyacrylamide into an aqueous drive fluid to increase its viscosity and hence to control its mobility through the formation. Unfortunately, substantial quantities of the polymer are employed to maintain a desirably high viscosity. Moreover, in many cases, particularly in a highly porous zone of relatively low porosity, substantial quantities of the drive fluid are recovered with the hydrocarbon.
As an alternative method for controlling the mobility of a drive fluid and/or water production in an oil-producing well, it has been proposed to plug some of the more porous formations by introducing a water-soluble acrylamide-carboxylic acid copolymer into the formation (see, e.g., U.S. Pat. No. 3,087,543). The polymer is forced into the formation and reduces the permeability of the formation to water without substantially decreasing the permeability of the same formation to hydrocarbon. Unfortunately, any beneficial effects only last for a relatively short time because of the inherent water-solubility of the polymer.
An improved method for controlling the flow of a fluid through a subterranean formation consists of injecting a cross-linked, water-insoluble gel of a water-soluble polymer into the formation (U.S. Pat. No. 3,921,733). Similarly, it has also been proposed to add discrete, spheroidal microgels of a water-swellable or water-swollen cross-linked polymer to the formation to control the mobility of fluids (see, e.g., U.S. Pat. Nos. 4,182,417 and 4,291,069). These cross-linked polymers have been shown to be effective in modifying the permeability of the formation to improve the efficiency of the recovery operation, thereby producing hydrocarbon which contains lesser amounts of water or other drive fluid. Unfortunately, due to their high viscosities, it is often difficult to pump the cross-linked polymer into the formation.
Alternatively, it has also become a practice to modify the control fluids in a formation by introducing a water-soluble polymer into the formation and cross-linking the polymer in situ using a metallic (e.g., sodium dichromate/sodium bisulfite) or an organometallic (e.g., aluminum citrate) cross-linking agent to form a water-soluble gel(see, e.g., U.S. Pat. Nos. 3,780,806; 3,785,437; 3,809,160 and 3,701,384). Unfortunately, the cross-linking of water-soluble polymers such as polyacrylamides and hydrolyzed polyacrylamides using a metallic or organometallic cross-linking agent can be difficult to control. Moreover, other materials present in the formation such as surfactants, soluble anions or dissolved gases can interfere with the cross-linking of the polymer.
In view of the deficiencies of the prior art methods, it remains highly desirable to provide an improved method for modifying the permeability of subterranean structures and hence, the flow of fluids therethrough.
SUMMARY OF THE INVENTION
Accordingly, in one aspect, the present invention is such a method for reducing the permeability of the more porous zones in a subterranean formation. Specifically, the method of the present invention comprises contacting the subterranean formation with at least one cross-linkable, water-soluble polymer having pendant carboxamide groups and a hypohalite cross-linking agent at conditions such that the polymer is or has been cross-linked to form a gel.
Using a hypohalite to cross-link the carboxamide polymer, a stable gel particularly useful for modifying the permeability of a subterranean formation is formed. The resulting gel is generally of lower toxicity and is more resistant to acidic or basic injection fluids than the cross-linked gels, formed by the methods of the prior art, which are used for the same purpose. The cross-linking reaction is also not found to be as significantly affected by other agents which may be present in the formation as is a metallic or an organometallic gelling agent. Moreover, the properties of the cross-linked polymeric gel are more easily controlled than when using a metallic or an organometallic gelling agent.
Using the described techniques, the permeability of the highly porous zones can be selectively reduced. For example, by the method of the present invention, the amounts of water native to the formation which are recovered in the production of a hydrocarbon can be effectively reduced. In addition, in a secondary or tertiary oil recovery operation or other operation in which a fluid is injected into an injection well to drive the oil or other hydrocarbon towards a producing wellbore, there is less tendency for the drive fluid to channel along or through the more permeable zones of the formation. As a result, the hydrocarbon is more uniformly forced towards the producing wellbore and the overall efficiency of the operation improved.
In another aspect, the present invention is such an improved enhanced oil recovery method. Specifically, in this aspect, the enhanced oil recovery method comprises injecting an aqueous drive fluid through an injection wellbore into a hydrocarbon-bearing formation to drive the hydrocarbon from the formation to a producing wellbore. The improvement in the method comprises introducing, through the injection wellbore, into the formation, a water-soluble carboxamide polymer and a hypohalite cross-linking agent in amounts and at conditions such that the polymer is or has been cross-linked to form a gel thereby restricting the passage of the drive fluid through the more permeable zones of the formation.
DETAILED DESCRIPTION OF THE INVENTION
The cross-linkable polymers suitably employed in the practice of the present invention are polymers (referred to herein as "carboxamide polymers") bearing pendant carboxamide groups with a carboxamide group being represented by the formula: ##STR1## wherein each R is individually hydrogen, alkyl or hydroxyalkyl, provided at least one R is hydrogen. Advantageously, the carboxamide polymers are at least inherently water-dispersible, i.e., can be dispersed in water to form a stable dispersion without the aid of a surfactant, and preferably, are water-soluble such that they are capable of forming at least a one weight percent solution when dispersed in an aqueous liquid, including aqueous acid or aqueous base. More preferably, the carboxamide polymer is soluble in water to the extent of at least 5 weight percent and most preferably to an extent of 20 percent of more by weight.
The carboxamide polymer can be a homopolymer of an ethylenically unsaturated carboxamide monomer, such as acrylamide, methacrylamide, fumaramide, ethacrylamide or the like, a copolymer of one or more carboxamide monomer(s) or a copolymer of two or more carboxamide monomer(s) with one or more other ethylenically unsaturated monomers copolymerizable therewith. Examples of copolymerizable monomers are water-soluble comonomers including ethylenically unsaturated anionic monomers such as unsaturated aliphatic acids and anhydrides, e.g., acrylic acid, methacrylic acid, maleic anhydride and their water-soluble salts, particularly alkali metal salts such as sodium acrylate or sodium methacrylate, and ethylenically unsaturated sulfonic acids such as vinyl benzyl sulfonic acid; ethylenically unsaturated cationic monomers such as aminoalkyl esters of unsaturated carboxylic acids, e.g., 2-aminoethyl methacrylate, and ethylenically unsaturated sulfonium compounds; nonionic water-soluble comonomers such as vinylesters of saturated carboxylic acids, e.g., vinyl acetate and vinyl propionate and the like.
In addition, various water-insoluble monomers such as monovinylidene aromatic compound, e.g., styrene; a vinyl halide, e.g., vinyl chloride or vinylidene chloride; and hydroxyalkyl and alkyl esters of α,β-ethylenically unsaturated carboxylic acids such as ethyl acrylate, methyl acrylate, butyl acrylate, methyl methacrylate, and hydroxyethyl acrylate can be employed in preparing the carboxamide polymer. It is understood that the specific comonomers employed and their concentrations are selected so that they do not react with the amide functionality of the carboxamide monomer or otherwise substantially interfere with the cross-linking reaction. Amide polymers are sometimes subject to some degree of hydrolysis during preparation or may purposefully have a portion of their amide groups hydrolyzed to carboxylate groups during or after preparation. For the purposes of this invention, such partially hydrolyzed amide polymer is equivalent to the corresponding copolymer of the carboxamide monomer and unsaturated aliphatic acid or acid-salt. Preferably, the carboxamide polymer is a homopolymer of acrylamide or a copolymer of acrylamide and an unsaturated carboxylic acid, preferably acrylic acid, or salt thereof.
Also included within carboxamide polymers which can be employed in the practice of the present invention, are those graft polymers wherein the amide monomer or other suitable monomers are grafted on cellulosic polymers such as cellulose, methylated cellulose and hydroxypropyl and methyl cellulose.
Preferably, the carboxamide polymer is a polymer wherein from about 50 to about 100 mole percent of the polymerized monomer units have pendant carboxamide groups. More preferably, from about 70 to about 100 mole percent and most preferably from about 80 to about 100 mole percent of polymerized monomer units contain carboxamide groups.
The molecular weight at which the polymer is most advantageously prepared is dependent on the specific monomeric components and cross-linking agent employed and the specific end-use application. Provided the carboxamide polymer has a sufficient molecular weight to react with the polyaldehyde to cross-link to a gel of desired properties, the molecular weight of the amide polymer is not particularly critical. The viscosity of an aqueous solution of the carboxamide polymer is an index of its molecular weight. In general, it is desirable that the carboxamide polymers have a molecular weight such that the desired amounts of polymer can be formed in an aqueous solution without producing excessive viscosity such as to render the solution difficult or impossible to pump. For example, the carboxamide polymers can have a significantly low molecular weight such that the viscosity of a 40 weight percent solution in water is only about 50 centipoise. Alternatively, the method of the present invention can alos be employed when the carboxamide polymer has a molecular weight characterized by a viscosity of as high as 60 centipoise for an aqueous 0.2 percent by weight solution of the polymer. In practice, to effectively influence the permeability of the subterranean formation, it is preferred to use solutions containing from 0.05 to 2 weight percent of the carboxamide polymer. In view of this, for ease of handling and placing the carboxamide polymer into the pore structure, an aqueous 20 percent by weight solution of carboxamide polymer is preferably characterized by a viscosity of from about 10,000 to about 30,000 centipoise measured using a Brookfield Viscometer, LVT Type (No. 5 spindle at 20 rpm) at 23° C.
The carboxamide polymer can be prepared in an aqueous solution using a variety of known techniques. For example, the carboxamide monomer(s) or monomer mixture containing the carboxamide monomer(s) can be dissolved in water and solution polymerization using free radical initiation, e.g., a redox catalyst system such as a peroxide-bisulfite system, or a peroxide or azo catalyst with controlled heating. Alternatively, the polymer may be prepared as a water-in-oil suspension or emulsion comprising a continuous phase of a water-insoluble liquid such as a liquid hydrocarbon and a disperse phase of droplets of an aqueous liquid containing the carboxamide polymer using techniques such as described in U.S. Pat. No. 3,284,393. Subsequently, the desired polymer solution can be prepared by inverting the emulsion, for example, with the aid of an inverting surfactant, to form an aqueous solution of the polymer. Alternatively, the amide polymer can be dried and redissolved in an aqueous liquid to form the suitable aqueous solution.
The hypohalite employed to cross-link the carboxamide polymer is suitably any hypohalite salt, including metal hypohalites, capable of cross-linking the carboxamide polymer. Advantageously, the hypohalite salt employed in the practice of the present invention is an alkali metal hypochlorite or alkali metal hypobromite, with an alkali metal hypochlorite being preferred. More preferably, the hypohalite is sodium or potassium hypochlorite, with sodium hypochlorite being most preferred.
The hypohalite salt is advantageously employed in the form of an aqueous solution prepared by dissolving the corresponding free halogen in a slight molar excess of alkali metal hydroxide or other relatively strong base with cooling to prevent the formation of halites or halates. In general, to stabilize the hypohalite solution, a slight excess of base is beneficially employed to provide an aqueous solution of hypohalite having a pH of at least about 12 and preferably at least about 13. Although the concentration of the hypohalite in solution can vary widely, in general, the hypohalite solution is prepared containing from about 5 to about 10 weight percent of the hypohalite salt and the solution diluted to from about 0.1 to about 0.5, weight percent prior to use. For economical reasons, it is most preferable to employ a commercial household bleach which is an aqueous solution containing about 5 to about 5.5 weight percent of sodium hypochlorite, an approximately equimolar proportion of sodium chloride and sufficient excess of sodium hydroxide to provide a solution having a pH of 13.5 or slightly higher. In commercial bleach, the stabilizing excess of NaOH corresponds to about 0.3 to 1 percent by weight of the solution.
The amounts of the hypohalite cross-linking agent most advantageously employed in the practice of the present invention are dependent on a variety of factors including the specific carboxamide polymer and hypohalite cross-linking agent employed, the conditions at which the cross-linking reaction is conducted, particularly the temperature and pH of the liquid in which gelation occurs and the desired properties of the resulting cross-linked product.
In normal practice, the hypohalite is advantageously employed in an amount from 1 to about 1000, preferably from about 10 to about 100, millimoles of hypohalite anion per mole of carboxamide moiety in the amide polymer.
In the practice of the present invention, the carboxamide polymer and hypohalite are introduced into the subterranean formation at conditions such that the carboxamide polymer is cross-linked, either prior, during or subsequent to its introduction into the formation, to form a gel. Although the carboxamide polymer can be cross-linked using the hypohalite to form a gel and the gel subsequently introduced into the subterranean formation, it is generally more advantageous if the gelling of the polymer is delayed until its introduction into the subterranean formation.
In general, solutions, at the desired concentrations of the carboxamide polymer and hypohalite salt, are advantageously added simultaneously or sequentially (preferably, the solution of the polymer being followed by the solution of the hypohalite) to the subterranean formation. Although any suitable liquid can be employed in forming the solutions of desired concentrations, the solutions of the carboxamide polymer and hypohalite salt are generally prepared using an aqueous liquid. Either tap water or deionized water can be employed in preparing the aqueous solution(s). However, it will often be more convenient to use the brine native to the subterranean formation to prepare an aqueous solution of the polymer or hypohalite. In addition, the aqueous liquid can be a mixture of water and a water-miscible organic liquid such as a lower aldehyde, e.g., methanol or ethanol; an organic acid; a glycol such as ethylene glycol or the like.
By varying the specific carboxamide polymer and hypohalite employed and by adjusting the temperature and/or pH of the reaction mixture, a wide range of gel times can be obtained and conditions are selected accordingly.
For example, the cross-linking reaction, particularly the rate of the reaction, is influenced, to a substantial extent, by the pH of the aqueous medium in which the reaction occurs. In general, to obtain a desired rate of cross-linking, the reaction mixture is advantageously maintained at a pH at least about 7. The maximum pH of the reaction mixture is advantageously less than about 12. Preferably, the pH is maintained within the range of about 7 to about 9, more preferably between about 7.2 and about 8.5. For optimum gel formation, the reaction medium most preferably exhibits a pH of from about 7.5 to about 8.5.
In general, the aqueous medium found in subterranean formations and/or employed in making the solution of the polymer or hypohalite do not possess such pH. therefore, it is normally desirable to add a basic material to the formation to cause cross-linking and gelation to occur within a reasonable amount of time. Generally, any base capable of generating the desired pH which does not otherwise interfere with the cross-linking reaction is usefully employed herein. Examples of basic materials which can advantageously be employed herein include alkali metal hydroxides; metal phosphates such as trisodium phosphate; metal carbonates such as disodium carbonate, alkylamines such as dimethylamine, methylamine and trimethylamine; and other organic bases such as ethylene diamine. Of the foregoing basic materials, alkali metal hydroxides, particularly sodium hydroxide and potassium hydroxide, and the metal phosphates, particularly trisodium phosphate are preferred.
In a preferred method, an aqueous solution of the carboxamide polymer, preferably containing from about 0.1 to about 4, more preferably from about 0.2 to about 2.5, most preferably from about 0.05 to about 2, weight percent of the polymer is mixed with the desired amounts of an aqueous solution containing from about 0.1 to about 20, more preferably about 0.2 to about 15, most preferably from about 0.25 to about 10, weight percent of the hypohalite and the resulting mixture introduced to the formation. Subsequently, if employed, the basic material, preferably in the form of an aqueous solution comprising from about 0.01 to about 5, more preferably from about 0.1 to about 1, weight percent of the basic material is added to the subterranean formation.
In the practice of the present invention in conjunction with the enhanced recovery of hydrocarbons using a fluid drive, i.e., a water or gas flood, the enhanced oil recovery operation is continued in a conventional manner until undesirable amounts of the drive fluid break through into the producing wellbore. At such time, the carboxamide polymer, hypohalite and, if employed, the basic material are introduced into the formation at conditions to cross-link the polymer and form a gel at the desired depth in the formation. In general, the introduction of the drive fluid is interrupted during the addition of the carboxamide polymer, hypohalite and other components and, subsequent thereto, to allow cross-linking of the polymer. Following gel formation, the drive fluid can be re-initiated for further recovery of the hydrocarbon from the hydrocarbon containing strata.
The following examples illustrate the invention but are not to be construed to limit its scope. All parts and percentages are by weight unless otherwise indicated.
EXAMPLE 1
To 100 milliliters (mls) of an aqueous solution containing about 1.5 percent of a polymer of acrylamide (30 percent hydrolyzed) having a weight average molecular weight of about five million and about 2 percent potassium chloride is added 2 mls of a 5 weight percent solution of household bleach (5.25 percent sodium hypochlorite). The resulting mixture is mixed thoroughly. Within an hour after initial mixing, a clear gel is formed. The gel reaches its final strength in about twenty-four hours. At this time, the gel is rigid and does not flow. The gel is stable and remains essentially unaffected to an aqueous buffer material having a pH of 3.2 and to an aqueous base solution containing about 2 percent sodium hydroxide.
EXAMPLE 2
To 100 mls of a fresh water solution containing about 2 percent of a low molecular weight polymer of acrylamide (non-hydrolyzed) having a weight average molecular weight of about 500,000 is added 10 mls water containing 0.8 percent trisodium phosphate and 4 percent sodium hypochlorite. The resulting mixture is mixed thoroughly. Within an hour after initial mixing, a clear gel is formed. The gel reaches its final strength in about twenty-four hours. At this time, the gel flows when acted upon the by the force of gravity. Specifically, the gel deforms when inverted and hangs from the container. The gel is stable and remains essentially unaffected to an aqueous buffer material having a pH of 3.2 and to an aqueous base solution containing about 2 percent sodium hydroxide.
EXAMPLE 3
In an enhanced oil recovery operation using a water-flooding technique, a well is producing little oil with a concurrent recovery of excess amounts of water which is being employed as the drive fluid. The method of the present invention can be used to control the mobility of the drive fluid in the following manner.
To 8,500 kg of an aqueous solution containing about 20 percent of a homopolymer of acrylamide (12 percent hydrolyzed) having a molecular weight of 500,000 which aqueous solution has a pH of about 11 and a viscosity of about 20,000 centipoise at 25° C. as determined using a Brookfield LVT viscometer, No. 5 spindle at 20 rpm is added sufficient amounts of available field brine to make a two percent solution of the polymer. To the resulting polymer solution is added 4,000 grams (g) of a commercial bleach (5.25 percent sodium hypochlorite) and 834 grams of a 1 percent aqueous solution of sodium triphosphate. The resulting mixture comprises about 100 millimoles of hypohalite per mole of carboxamide moiety on the polymer. The resulting solution is thoroughly mixed and then injected into the formation through an injection wellbore. Following the additon of the solution into the formation, 85,000 kg of water are added to the formation to push the mixture into the formation and away from the wellbore. The injected materials are allowed to stand for 48 hours. After that period, water flooding is again commenced at the same conditions as prior to the treatment. Within several days, an increase in the average output of oil and a decrease in the average output of water is noticed.
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The permeability of subterranean formations, and hence, the mobility of fluids through the formation, can be controlled by introducing a carboxamide polymer and a hypohalite such as sodium hypochlorite to the formation at conditions such that the polymer has been cross-linked, either prior to its introduction or in situ, to form a gel. By this method, the permeability of highly porous zones can selectively be reduced. Therefore, in an enhanced recovery operation wherein a drive fluid is injected into the subterranean formation to force hydrocarbon therefrom, the drive fluid can more uniformly sweep the formation resulting in a more effective recovery process.
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CONTRACTUAL ORIGIN OF THE INVENTION
This invention was made with United States Government support under Contract No. DE-AC22-88ID12735 awarded by the Department of Energy. The Government has certain rights in this invention.
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
The present invention is related to two co-pending U.S. Patent Applications. A first related application (Ser. No. 08/192,691) entitled "Method and Apparatus for Spraying Molten Materials", has a common assignee with the present patent application. The first application was filed concurrently with the present application and has as its inventors, R. J. GLOVAN, J. TIERNEY, L. JOHNSON, L. MCLEAN, G. NELSON, & Y. M. LEE. A second related application (Ser. No. 08/192,697) entitled "Heater for Metal Spray Apparatus" has a common assignee with the present patent application. The second application is being filed concurrently with the present patent application and has as its inventors, R. J. GLOVAN, J. TIERNEY, L. JOHNSON, L. MCLEAN & D. VERBAEL.
FIELD OF THE INVENTION
The invention relates to self-locking threaded fasteners.
BACKGROUND OF THE INVENTION
In many instances, there is a need to fasten two objects together so that they can be subsequently separated without destruction of either of the objects. This problem has been solved imperfectly by the use of threaded fasteners. There are many threaded fasteners which have a self-locking feature, but there are none with the degree of reliability which results from a riveted or welded connection between objects. It has been a long sought after goal to provide a threaded fastener which will operate with the reliability of a riveted or welded connection. This need for reliability is particularly acute where assembled objects operate at high temperatures. Typical high temperature applications such as engines and turbines are ones in which assembled parts are heated during operation of the engine or turbine and then cooled when the engine or turbine is not operating. This temperature cycling produces severe expansion and contraction of a threaded fastener. The cyclical expansion and contraction takes a toll on fastener reliability.
Many prior art self-locking threaded fasteners rely on elastomeric inserts as locking devices. These fasteners are unsuitable for high temperature applications, i.e., temperatures above 200 degrees centigrade. When these fasteners are exposed to high temperatures such as those encountered in a turbine, the elastomeric inserts are useless because they disintegrate.
Another problem that develops with threaded fasteners in high temperature settings is corrosion. Typically, the fastener is made from a material that is dissimilar to the objects being held together. Virtually any dissimilarity between adjacent metal at high temperature will result in corrosion. When a threaded fastener corrodes, it loses some of its strength. Corrosion of a fastener also creates an undesirable adhesion between the threads of the fastener and the objects being fastened. Consequently, when the time comes to disassemble the secured objects, it is often the case that the fastener will not unthread from the object but will instead break away inside the object.
It is desirable therefore to provide a self-locking fastener that is highly reliable when securing objects at a high temperature but will be readily releasable when the objects are at a low temperature. It is also desirable that such a fastener can be produced in an expedient and cost effective manner.
SUMMARY OF THE INVENTION
The present invention is directed to a producing a threaded fastener with a coating of shape memory alloy on its threads. When the fastener is inserted at a low temperature, the coating readily distorts. When the fastener is raised to a higher temperature, the coating changes its crystal structure and produces a locking stress on the fastener. When the fastener is cooled the locking stress is relieved and the fastener is readily removable.
Viewed from one aspect the present invention is directed to a threaded fastener which comprises a threaded member and a coating of shape memory alloy on the threads of the member.
Viewed from another aspect, the present invention is directed to a male threaded fastener that comprises a threaded base member having thread dimensions which are no larger than a corresponding opening in a female threaded opening into which the base member is to be inserted. A coating of shape memory alloy is applied to the threads of the base member, which coating has a thickness sufficient to produce an interference fit between the male threaded fastener and the female threaded opening into which the male threaded fastener is to be inserted.
Viewed from yet another aspect, the present invention is directed to a method of producing a threaded self-locking fastener. The method comprises the steps of producing a spray plume of droplets of molten shape memory alloy and placing the threaded fastener into the spray plume to coat the threads of the fastener with the shape memory alloy.
Viewed from still another aspect, the present invention is directed to a method of fastening a female threaded object into a desired location which location is intended to be exposed to temperatures above 100 degrees centigrade. The method comprises the steps of determining the inside diameter of the female threads, coating threads of a male threaded fastener with a shape memory alloy so that the overall outside diameter of the coated threads exceeds the inside diameter of the female threads, and inserting the coated male threaded fastener into the female threaded object at a temperature below 35 degrees centigrade whereby the coating of shape metal alloy is distorted and will subsequently produce a locking stress on the female object when the female object is heated to a temperature above 100 degrees centigrade.
The invention will be better understood from the following detailed description taken in consideration with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows, symbolically, a metal spray apparatus which is useful in producing objects in accordance with the apparatus 10;
FIG. 2 shows a comparative graphical relationship between inlet pressure and throat pressure in prior art apparatus and the apparatus of FIG. 1;
FIG. 3 shows a sectional view of a nozzle that is used in the apparatus of FIG. 1;
FIG. 3A is a detailed view of a portion of the nozzle of FIG. 3;
FIG. 4 shows an elevational, partially sectioned view of a portion of the apparatus of FIG. 1;
FIG. 5 shows a perspective view of a heater that is part of the apparatus of FIG. 1;
FIG. 6 is a sectional view of a gas heater portion of the apparatus of FIG. 1;
FIG. 7 is an end view of a heating element of the gas heater of FIG. 6;
FIG. 8 is elevational view of the heating element of FIG. 7;
FIG. 9 is a symbolic representation of a portion of the apparatus of FIG. 1 showing one operational aspect thereof;
FIG. 10 is a symbolic representation of a portion of the apparatus of FIG. 1 showing another operational aspect thereof;
FIG. 11 is a symbolic representation of a method of producing objects in accordance with the present invention; and
FIG. 11A is a partial cross-sectional view of a fastener of FIG. 11 showing a coating of Shape Memory Alloy thereon.
The drawings are not necessarily to scale.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown symbolically a metal spraying apparatus 10 that is useful in producing fasteners in accordance with the present invention. The apparatus 10 comprises a chamber 12, a nozzle 14 (shown partially sectioned for purposes of clarity), a tundish assembly 16 (shown partially sectioned for purposes of clarity), a heater 18 (shown partially removed for purposes of clarity), a metal source unit 20, a gas heater 22, a tundish pressure control unit 24, a heater control unit 26, a gas delivery unit 28, an exhaust unit 30 and a substrate support 32. The substrate support 32 holds an object to be sprayed or a substrate 34 within a spray plume 36.
The tundish assembly 16 and the metal source unit 20 are coupled to the nozzle 14. The heater 18 surrounds the nozzle 14 and the tundish assembly 16. The nozzle 14, the tundish assembly 16, the heater 18, and the substrate support 32 are enclosed within the chamber 12. The gas heater 22 is coupled to the nozzle 14 through a wall of the chamber 12. The metal source unit 20 is coupled to the tundish assembly 16 through a wall of the chamber 12. The chamber 12 is adapted to maintain a desired ambient pressure therein. The exhaust unit 30 is coupled to the chamber 12 and is adapted to withdraw and filter exhaust gases from the chamber 12. The tundish pressure control unit 24 is coupled to the metal source unit 20 The heater control unit 26 has a first output coupled to the heater 18 and a second output coupled to the gas heater 22. The gas delivery unit 28 is coupled to an input end of the gas heater 22.
In operation, the metal spraying apparatus 10 produces a spray plume 36 of uniformly sized droplets of liquid metal which are propelled against a surface of the substrate 34 to produce a coating of metal on the substrate 34. The plume 36 is produced as gas flows from the gas delivery unit 28 through the gas heater 22 and through the nozzle 14. Metal is introduced into the gas through a port 38 which interconnects an interior of the nozzle 14 with an interior of the tundish assembly 16. Within the interior of the tundish assembly 16, there is a pool 39 of liquid metal which is generated by the metal source unit 20. The heater 18 maintains the temperature of the nozzle 14 and the tundish assembly at a high enough level so that liquid metal produced by the metal source unit 20 remains in a molten state. The nozzle 14 has a converging-diverging configuration and is capable of accelerating gas from a sub-sonic to a supersonic velocity. The port 38 which interconnects the interior of the tundish assembly 16 with the interior of the nozzle 14 is positioned at a point in the nozzle 14 where the shape of the nozzle 14 changes from a converging to a diverging cross-section. This arrangement results in the production of liquid metal droplets which have a very uniform size. These highly uniform droplets exit the nozzle in the form of the plume 36 which deposits a uniform coating of the metal on the substrate 34.
The tundish pressure control unit 24 produces a static pressure on the pool 39 of the liquid metal that is held in the tundish assembly 16. As the static pressure is increased, the droplets of metal within the plume 36 are increased in size. Conversely, when the static pressure from the tundish pressure control unit 24 is decreased, the droplet size within the plume 36 is reduced. Even though the droplet size can be changed from large to small, the droplet size uniformity does not change. For example, if at a given static pressure of 1800 mm Hg the droplet size in the plume 36 is nominally 10 microns, the variation in size of any one droplet relative to all the other droplets is no greater than about 10 percent. Similarly, if at a static pressure of 2000 mm Hg, the droplet size in the plume 36 is 15 microns, the variation in size from one droplet to all other droplets in the plume 36 is no greater than about 10 percent.
The achievement of this type of control provides a marked departure over prior art systems. In prior art systems such as conventional twin wire arc systems, a spray plume is generated with droplets which vary in size relative to one another 500 percent or more. In other prior art spraying systems such as that disclosed in U.S. Pat. No. 4,919,853 (Alvarez et al.) issued Apr. 24, 1990 the spray droplets are uniform in size, but the Alvarez et al. spraying system cannot be readily adapted to produce a relatively large droplet spray for one application and a smaller droplet spray for some other application in which a smaller droplet spray is more suited. The apparatus 10 is uniquely capable of producing spray plumes with uniformly sized droplets with a large range of selected diameters with a wide range of droplet velocities. This flexibility is achieved because the apparatus 10 can be operated with a wide range of gas flow rates.
Because of this flexibility, it is possible to employ the apparatus 10 to produce metal powders of uniform size. This can be done by spraying metal into the chamber 12 and allowing the metal droplets to freeze before they strike an object or substrate.
Referring now to FIG. 2, there is shown a graph 40 that displays differences in operating parameters between the apparatus 10 and the prior art as embodied in the Alvarez et al. patent. A graph line 42 depicts a relationship between inlet pressure at an inlet end of a converging-diverging nozzle and throat pressure at a selected point in a throat of the nozzle. A horizontal line 44 represents a typical ambient pressure within a chamber in which the nozzle is located. It can be seen that when the inlet pressure is equal to the ambient pressure, the throat pressure is also equal to ambient pressure as shown at a point 46. As the inlet pressure increases, the throat pressure decreases to a minimum at point 48. Increasing inlet pressure eventually produces a condition in which the throat pressure is once again at ambient pressure. This is shown at a point 50. The nozzle of the Alvarez et al. patent must operate within a range of inlet pressures shown between the points 46 and 50. These points represent the range of inlet pressures which will produce throat pressures below ambient pressure. In other words, points 46 and 50 show the range of operation of a nozzle which is dependent upon aspiration for its operation.
The nozzle 14 of the apparatus 10 is operable throughout the entire range of pressures shown between the point 46 and a point 52. It has been found that an ideal range of operating conditions for the nozzle 14 of the apparatus 10 is shown between a point 54 and the point 52. The nozzle 14 is not dependent on the principle of aspiration for its operation. Because a negative throat pressure is not required, the inlet pressure can be increased substantially above ambient pressure. Additionally, the pressure can be varied widely. This variability of inlet pressure produces great flexibility in the flow rate of gas through the nozzle 14. This flexibility in choice of flow rate provides an opportunity to choose a flow rate which produces an optimum particle size and particle velocity for every coating application.
Because the molten metal is independently pressurized, the metal can be injected at higher pressures. This enhances atomization and mixing by assuring that the droplets penetrate further into the gas flow through the nozzle 14. By extending the range of nozzle inlet pressures, substantially higher gas and droplet velocities can be achieved at the exit of the nozzle 14. Since adhesion strength and density generally improve as droplet velocity increases, this feature enhances the quality of a sprayed coating produced by the apparatus 10.
In order to assure repeatability and uniformity of operating characteristics of the apparatus 10, the chamber 12 is maintained at a controlled ambient pressure. The controlled ambient pressure in the chamber 12 allows the apparatus 10 to function independently of local atmospheric conditions.
Because of inherent flexibility of the apparatus 10, we have found that a single configuration of the nozzle 14 of FIG. 1 is suitable for a wide range of applications.
Referring now to FIGS. 3 and 3A there is shown a cross-sectional view of the nozzle 14. The nozzle comprises a conical converging section 60, a conical diverging section 62 and a cylindrical throat section 64. The port 38 enters the throat section 64. It has been found that suitable material for the nozzle 14 is boron nitride. FIG. 3 shows a series of dimensional relations indicated with the letters A through F. The nozzle 14 has been found to perform effectively within the following ranges of the dimensions A through F:
A between about 2 degrees and 7 degrees;
B between about 3 degrees and 7 degrees:
C between about 4 inches and 7 inches
D between about 0.5 inches and 0.75 inches;
E between about 0.04 inches and 0.05 inches;
F between about 0.08 inches and 0.12;
We have found that the diameter of port 38 can be between about 0.008 and 0.012 inches. We have also found that the centerline of the port 38 should be located at a midpoint of the throat section 62 or toward the exit end thereof.
Referring now to FIG. 4 there is shown a detailed, partially sectioned elevational view of an embodiment of the apparatus 10. A portion of the metal source unit 20 of FIG. 1 is in contact with the tundish assembly 16. The tundish assembly 16, the nozzle 14 and the heater 18 are encased in an insulator 66. The insulator 66 is formed from a material known as rigidized carbon felt. This material is available as a commercial product from companies such as Polycarbon Inc of Valencia, Calif. The gas heater 22 of FIG. 1 extends through a wall of the chamber 12.
The heater 18 is formed of a single piece of graphite in a serpentine configuration that effectively surrounds the nozzle 14 and a lower portion of the tundish assembly 16. A more detailed description of the heater 18 is provided hereinbelow in connection with a discussion of FIG. 5.
The tundish assembly 16 is comprised of a tundish 80, an inner metal source adapter 82, an outer metal source adapter 84, a set of o-rings 86, a water-cooled ring 87 and a threaded fastener 88. It can be seen that an upper portion of the outer metal source adapter 84 projects out of the insulator 66. During operation, this upper portion remains in contact with a lower end 89 of the metal source unit 20. In the case of the embodiment of the invention shown in FIG. 1, the metal source unit 20 is a conventional twin wire arc unit such as a Model 9000 manufactured and sold by Hobart/Tafa of Concord, N.H. In this type of twin wire arc unit, the lower end 89 of the unit 20 is water cooled. This water cooled feature of the unit 20 is used advantageously in the apparatus 10. When the water cooled lower end 89 is placed into contact with the outer metal source adapter 84, the adapter 84 transfers its stored heat to the unit 20. The water-cooled ring 87 provides additional cooling. Thus the portion of the adapter 84 which projects out of the insulator 100 remains relatively cool. Because this projecting portion of the adapter 84 remains cool, the adapter can be fitted with conventional o-rings 86 and the o-rings 86 do not melt. Thus an effective pressure seal between the unit 20 and the tundish assembly 16 can be maintained. This is of critical importance in the apparatus 10 because it is necessary to maintain a desired static pressure on the molten metal which is held in the tundish 80. As was discussed in connection with FIG. 1, the desired static pressure is generated in the metal source unit 20 by the tundish pressure control unit 24 of FIG. 1. Thus a positive pressure seal between the tundish 80 and the metal source unit 20 is a requisite to maintaining a desired static pressure on the molten metal in the tundish 80.
Referring back new to FIG. 1, the utility of the o-rings 86 can be even better understood when one considers how the metal spray apparatus 10 is initially set up and brought to operating conditions. In order to avoid any oxidation of the metal droplets in the plume 36, the spraying operation is preferably carried out in an inert gas atmosphere within the chamber 12. This inert gas atmosphere is produced by first drawing a vacuum in the chamber 12 and then backfilling the chamber 12 with an inert gas such as argon. During the drawing of the vacuum, it is necessary that the lower end 89 (FIG. 2) of the metal source unit 20 be removed from the chamber 12. If the lower end 89 were to be allowed to remain in the chamber 12 during this set-up stage, a vacuum could not be successfully produced because the unit 20 is not sufficiently leak resistant. Thus the chamber 12 is provided with a conventional gate valve (not shown) though which the lower end 89 of the metal source unit 20 is inserted after the chamber 12 is charged with argon at the desired ambient pressure. In order to assure that the apparatus 10 is an efficient manufacturing unit, it is necessary that the lower end 89 can be coupled easily and quickly with the tundish assembly 16. The o-ring 86 (FIG. 4) seal on the outer metal source adapter 84 (FIG. 4) allows for the desired expedient coupling. The lower end 89 simply slides into the outer metal source adapter 84.
Referring now to FIG. 5 there is shown a detailed perspective view of the heater 18 employed in the apparatus 10. The heater 18 is formed from a continuous piece of solid graphite. The heater 18 is shaped so that it comprises a nozzle heating portion 90, a tundish heating portion 92 and first and second power connectors 95 and 96, respectively. The heater 18 is formed in a serpentine configuration with grooves and cylindrical holes formed therein to produce a substantially uniform cross-sectional area of the graphite along a current path that extends from the first power connector 94 to the second power connector 96. The nozzle heating portion 90 and the tundish heating portion 92 are shaped basically like two hollow cylinders with intersecting axes. For purposes of clarity, the heater is designated to have an entrance end 93, a top side 95, a bottom side 97 and an exit end 99.
A cylindrical hole 98, large enough to accommodate the nozzle 14 (FIG. 1) is formed on an axis parallel to the nozzle heating portion 90. A cylindrical hole 101 large enough to accommodate the tundish assembly 16 (FIG. 1) is formed in the tundish heating portion 92 on a axis parallel with the tundish heating portion 92. A slot 105 extends through a wall of the tundish heating portion 92 on the exit end 99 of the heater 18. A slot 107 extends through the wall of the nozzle heating portion 90 along the entire bottom side 97 of the nozzle heating portion 90. First, second third and fourth transverse slots designated 109, 110, 112 and 114, respectively extend through the walls of the heater 18. The first transverse slot 109 extends through a portion of the wall of the tundish heating portion 92 which faces the entrance end 93 of the heater 18. The first transverse slot 109 also extends from a point approximately midway along the axis of the tundish heating portion 92 to a point that is approximately aligned with a central axis of the nozzle heating portion 90. The second transverse slot 110 extends from the bottom side 97 of the nozzle heating portion 90 to a point that is substantially aligned with the central axis of the nozzle heating portion 90. The third transverse slot 112 extends from the top side 95 of the nozzle heating portion 90 to a point that is substantially aligned with the central axis of the nozzle heating portion 90. The fourth transverse slot 114 extends through the wall of the tundish heating portion 92 on the side of that portion which faces the entrance end 93 of the heater 18. The fourth transverse slot 114 intersects with the first transverse slot 109.
This arrangement of slots and holes produces a path for electric current in the graphite of the heater 18 which has a substantially uniform cross-sectional area. The current path extends from the first power connector 95 down to the bottom side 97 between the entrance end 93 and the transverse slot 112. Then the current path goes to the top side 65 between the transverse slots 112 and 110. The current path then goes to the bottom side 97 between the transverse slots 110 and 109. The current path then goes into the tundish heating portion 92 between the slot 105 and the transverse slot 109. The current path proceeds around a top of the tundish heating portion 92 and down the far side of the slot 105. The current path follows a similar course on the far side of the heater 18 until the path terminates at the second power connector 96.
The sizes of the holes and slots are selected so that the resultant heater is comprised of graphite that has a substantially uniform cross-sectional area along the entire length of the current path. When electric current is introduced to the heater 18 through the power connectors 95 and 96, there is a substantially uniform voltage drop along the entire current path. This results in a substantially uniform temperature distribution around the entire volume of the heater 18.
This arrangement is particularly desirable in the operation of the metal spray apparatus 10 (FIG. 1) because a uniformity of temperature of the nozzle 14 (FIG. 1) and the tundish 80 (FIG. 2) is essential to achieving a uniformity of size in the droplets of liquid metal which the apparatus 10 produces.
If the tundish 80 and the nozzle 14 were heated with separate heaters, then there would be a need to use complex control systems to assure that the temperatures of both of the separate heaters remained the same. The unique design of the heater 18 permits the use of one simple current controller to control temperature of both the nozzle 14 and the tundish 80.
Referring now to FIG. 6 there is shown a cross-sectional view of the gas heater 22 of FIG. 1. The gas heater 22 comprises a resistance heating element 120, a cylinder of rigidized carbon felt insulation 122, two water-cooled electrodes 124 and 126, a gas inlet 128, a gas outlet 130, a water-cooled cover plate 132, an end plate 134, a water-cooled heater vessel 136 and a heater extension 138. The heating element 120 is supported by the end plate 134 within a cylindrical opening in the insulation 122. The element 120 and the insulation 122 are aligned with each other so that a substantially uniform annular space is developed along the length of the element 120. The annular space forms a passageway through which gas flows. The electrodes 124 and 126 are each coupled to one side of the element 120. Water cooling in the vessel 136, the electrodes 124 and 126, and the cover plate 132 prevents these items from melting during operation of the heater 22.
Referring now to FIGS. 7 and 8, there is shown a detailed side view and end view of the heater element 120 of FIG. 5. The element 120 is comprised a top leg 140 and a bottom leg 142. The legs 140 and 142 traverse almost the entire length of the element 120. Each of the legs 140 and 142 are provided with electrode attachment points 144 and 146, respectively. The legs 140 and 142 are interconnected at an end 148. It can be seen that the element 120 is essentially a solid cylinder with a horizontal slot formed along almost its entire length. The slot does not pass through the end 148. Thus the resulting structure of the element is a long U-shaped cylinder with a substantially uniform cross-sectional area. An outer surface of the element 120 is covered with threads 150 as shown in a detail bubble portion of FIG. 8. Materials such as graphite or a refractory metal such as molybdenum are suitable for construction of the element 120.
Referring back now to FIG. 6, it can be seen that in operation the gas heater 22 achieves a high temperature when low frequency, AC current is passed through the electrodes 24 and 126. A current path passes into the electrode 124, continues into and along the top leg 140 of the element 120. The current path continues around the end 148 of the element 20, then along the other leg 142 and finally into the electrode 126. Gas passes over the threaded surface of the element 120 in the annular opening between the element 120 and the insulation 122 of FIG. 6. The threads 150 produce turbulence in the gas, thus providing for an optimization of heat transfer from the element to the gas. The annular space between the element 120 and the insulation 122 is about 0.065 inches. The threads 150 are about 0.035 inch or greater in depth. This combination produces a virtually complete turbulence in the gas flow in the annular space.
As the gas passes along the length of the element 120, the gas becomes progressively hotter. In fact, when the gas reaches the end 148, the temperature of the gas can be as high as 2000 degrees centigrade.
The unique utility of the shape of the element 120 can be best understood when considering the high exit temperature of the heater 22. Both of the electrodes 124 and 126 are attached to the element 120 at an input end of the heater 22 where the gas temperature is relatively low. Thus the electrodes 124 and 126 are able to operate in temperature conditions in which they do not melt. If either of the electrodes were to be located near the output end of the heater 22, then the heater could not be operated at such a high temperature because such an electrode would melt if the electrode were not water cooled. However if the electrode were water cooled, then the exit gas temperature would be reduced. Therefore, it can be seen that the unique U-shaping of the element 120 provides for a gas heater that can be operated at heretofore unattainable output temperatures.
When the unique gas heater 22 of FIG. 6 is combined with the unique nozzle and tundish heater of FIG. 5, there is an extraordinary capability imparted to the spraying apparatus 10 of FIG. 1. Gas injected into the nozzle 14 can be heated to temperatures in excess of 2000 degrees centigrade. This extremely hot gas can undergo substantial heat losses during expansion in the nozzle 14 and still emerge from the nozzle 14 at a high enough temperature to provide a very hot carrier for metal droplets. Thus the droplets do not freeze during transit to the substrate. In this regard, the apparatus 10, is uniquely capable of operating with high pressures in the throat of the nozzle 14. High pressure in the throat of the nozzle 14, of course, permits the nozzle 14 to spray metal without aspiration. Consequently, the apparatus 10 is operable in a much wider range of gas flow and pressure conditions than those to which prior art metal spray equipment is limited.
Referring now to FIGS. 9 and 10 there is shown, symbolically, an operational sequence of the metal spray apparatus 10. The nozzle 14 is shown projecting through the wall of the chamber 12. Attached to the chamber 12 there is a sub-chamber 152. The sub-chamber 152 is provided with an isolating door 154. A robotic unit 156 is mounted within the chamber 12. The robotic unit 156 is adapted to reach into the sub-chamber 152 through the door 154 and pick up a substrate or workpiece 158. After one of the workpieces 158 is engaged with the robotic unit 156, the unit moves the engaged workpiece 158 into position in front of the nozzle 14 as shown in FIG. 10. After the engaged workpiece 158 is in position in front of the nozzle 14, the spraying operation is started and the workpiece 158 is coated with a desired metal.
After the workpiece 158 is coated, the robotic unit 156 returns the coated workpiece 158 to the sub-chamber 152 as shown in FIG. 9. The robotic unit 94 then engages with one of the uncoated workpieces 158 and the above described process is repeated. In this way a plurality of the workpieces 158 can be coated without a need to open and recharge the chamber 12 with inert gas. Use of the sub-chamber 152 with its isolating door 154 permits each of the workpieces 158 to be independently coated without risk of cross-contamination. In other words, each of the workpieces 158 is coated separately and the workpieces 158 in the sub-chamber 152 are not subject to being undesirably contacted with overspray particles.
The apparatus 10 can also produce objects of near-net shape. A mold (not shown) with an impression of a desired shape can be used as the workpiece 158. The spray plume 36 is directed into the mold and the mold becomes coated with metal to fill the impression. When the solidified metal is removed from the mold, an object of the desired shape is obtained.
Referring now to FIG. 11 there is shown a particularly useful application of the metal spraying apparatus of FIG. 1 which is in accordance with the present invention. FIG. 11 show a threaded fastener 160 positioned in front of the nozzle 14. A portion of the fastener 160 is in the spray plume 36. The tundish assembly 16 is charged with a specialized molten metal known as a shape memory alloy (SMA).
In operation, the robotic unit of FIGS. 9 and 10 moves the fastener 160 vertically and rotationally within the spray plume 36 so that all of the threads of the fastener 160 are uniformly exposed to the spray plume 36. This results in the threads being coated with shape memory alloy.
A coating 162 of the SMA is shown in FIG. 11A, which is a partially sectioned view of the fastener 160.
Shape memory alloys (SMA), such as those obtainable from TiNi Alloy Company, San Leandro, Calif., have unique characteristics. When an SMA is cold or below its transformation temperature, it has a very low yield strength and can be deformed quite easily into any new shape. However, when the material is heated above its transformation temperature, it undergoes a change in crystal structure which causes it to become hard and to return to its original shape.
These characteristics are used advantageously on the threaded fasteners 160. The fasteners 160 are coated with SMA to a coating thickness that results in an interference fit between the male threads of the fastener 160 and the female threads of the object into which the fastener is to be placed. This results in a distortion of the SMA coating when the fastener 160 is installed. This distortion is particularly useful when the fastener 160 is used to secure components that operate in a high temperature environment. As the component is placed into service where its temperature rises, e.g., engines. turbines, etc., the SMA undergoes a transition to a different crystal structure that has a much higher yield strength and attempts to restore itself to its original dimensions. This stress locks the fastener 160 in place. When the component cools, transition to the low temperature crystal occurs and the fastener can be readily removed.
Thus the fastener 160 operates at high temperatures with all the security of a rivet or weld, but at low temperatures, the fastener 160 operates with all the convenience of a bolt.
We have found that when the fasteners 100 are installed at temperatures below 35 degrees centigrade, they will develop a substantial locking stress at temperatures above 100 degrees centigrade. We have also found that when the spray plume 36 is comprised of droplets no greater in diameter than 100 microns then the fasteners 100 achieve a predictable and repeatable locking stress at high temperatures.
It is to be appreciated and understood that the specific embodiments of the invention are merely illustrative of the general principles of the invention. Various modifications may be made by those skilled in the art which are consistent with the principles set forth. For example, it is possible to apply coatings of shape memory alloy to threads of fasteners with electroplating techniques.
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A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures.
A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy.
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FIELD OF THE INVENTION
The exemplary embodiment(s) of the present invention relates to bone repairing substance for medicaments. More specifically, the exemplary embodiment(s) of the present invention relates to a bone cement formula.
BACKGROUND OF THE INVENTION
Bone cement compositions are widely used in bonding, filling, and/or repairing damaged natural bone. Bone cement is typically used in orthopedic, dental procedures, and/or other medical applications.
The applicant of the present application in U.S. patent application Ser. No. 12/907,091, filed 19 Oct. 2010, discloses a bone cement formula having a powder component and a setting liquid component, wherein the powder component includes a calcium sulfate source and a calcium phosphate source with a weight ratio of the calcium sulfate source less than 65%, based on the total weight of the calcium sulfate source and the calcium phosphate source, and the setting liquid component comprises ammonium ion (NH 4 + ) in a concentration of about 0.5 M to 4 M, wherein the calcium phosphate source includes tetracalcium phosphate (TTCP) and dicalcium phosphate in a molar ratio of TTCP to dicalcium phosphate of about 0.5 to about 2.5, and the calcium sulfate source is calcium sulfate hemihydrate (CSH), calcium sulfate dehydrate (CSD), or anhydrous calcium sulfate. The disclosure of the U.S. patent application Ser. No. 12/907,091 is incorporated herein by reference.
For a minimally invasive procedure of injecting a cement paste into a bone cavity, a thin, long tube is usually used for the transportation of the paste. To more easily deliver the paste through such long, thin tube, use of a less viscous (more dilute or higher LIP ratio) paste has its inherent advantages. However, a less viscous paste has higher tendency to be dispersed upon contact with water, body fluid or blood. The dispersion of the paste into its original powder form may cause various clinical complications, such as cement embolism.
SUMMARY OF THE INVENTION
A primary objective of the present invention is to provide a calcium-based bone cement composition with enhanced non-dispersive ability.
It is discovered that adding a very small amount of poly(acrylic acid) in the calcium-based bone cement can dramatically lower the possibility/risk of dispersion of the resulting cement paste. In other words, with addition of a small amount of poly(acrylic acid), the cement paste can tolerate a more dilute (higher LIP ratio) paste, which can be more easily delivered minimally invasively, without worrying about its being dispersed when injected into a bone cavity or other types of implantation site.
The embodiments of the present invention provides methods for providing a bone cement formula, bone cement paste, hardened bone cement composite, hardened bone cement composite with enhanced strength, and porous hardened bone cement composite.
An embodiment of the present invention provides a method for filling a hole or cavity in a bone with an exemplary embodiment of bone cement paste which will cure or harden in a hole or cavity in need of treatment. Another embodiment of the present invention provides a method for implanting hardened bone cement composite during a treatment.
One embodiment of the present invention provides a calcium-based bone cement formula comprising a powder component and a setting liquid component with a liquid to powder ratio of 0.20 ml/g to 0.50 ml/g, preferably 0.25 ml/g to 0.45 m/g, wherein the powder component comprises a calcium phosphate source and the calcium phosphate source comprises tetracalcium phosphate (TTCP), characterized in that the bone cement formula further comprises, based on the total weight of the bone cement formula, 0.01-1%, preferably 0.03-0.5%, of poly(acrylic acid) having a repeating unit of —(CH 2 —C(COOH)H)n-, wherein n=50-50000, preferably 1000-5000, and more preferably 1500-2500.
Preferably, the poly(acrylic acid) is liquid, and is contained in the setting liquid component. Alternatively, the poly(acrylic acid) is solid, which can be powder, and contained in the powder component or dissolved in the setting liquid component prior to mixing the powder component and the setting liquid component.
In one embodiment, the powder component further comprises 5-65% of a calcium sulfate source, based on the total weight of the calcium sulfate source and the calcium phosphate source powder. The calcium sulfate source is calcium sulfate hemihydrate (CSH), calcium sulfate dehydrate (CSD), or anhydrous calcium sulfate, and preferably, CSH. The calcium phosphate source, in one aspect, further includes dicalcium phosphate, preferably dicalcium phosphate anhdydrous (DCPA), in a molar ratio of TTCP to dicalcium phosphate of approximately 0.5 to 2.5, preferably about 08 to 2.0, and more preferably about 1.0.
In one embodiment, the setting liquid component comprises ammonium ion (NH 4 + ) in a concentration of about 0.075 M to 3.0 M.
The setting liquid component, in one example, is a solution of NH 4 H 2 PO 4 , (NH 4 ) 2 HPO 4 , (NH 4 ) 3 PO 4 .3H 2 O, (NH 4 ) 3 PO 4 or a mixture of them. Preferably, the setting liquid component is a solution of (NH 4 ) 2 HPO 4 . Preferably, the setting liquid component is an aqueous solution.
In one embodiment, the bone cement formula further comprises, based on the total weight of the powder component, 0.1-5%, preferably 0.25-5%, of a magnesium setting modifier selected from an oxide, hydroxide, fluoride, chloride, carbonate, phosphate, sulfate and silicate of magnesium. Preferably, the magnesium setting modifier is an oxide, phosphate or sulfate of magnesium, and more preferably, magnesium sulfate.
Additional features and benefits of the present invention will become apparent from the detailed description, figures and claims set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 ( a ) and ( b ) are photographs showing green bodies of bone cement pastes (TTCP/DCPA:CSH=65/35, 0.45 M (NH 4 ) 2 HPO 4 , L/P=0.30 cc/g) injected into Hanks' solution, wherein ( a ) is without an addition of poly(acrylic acid) (abbreviated as PAA), and ( b ) is with an addition of 3 vol % PAA according to the present invention, respectively.
FIGS. 2 ( a ) and ( b ) are photographs showing green bodies of bone cement pastes (TTCP/DCPA:CSH=65/35, 0.60 M (NH 4 ) 2 HPO 4 , L/P=0.33 cc/g) injected into Hanks' solution, wherein ( a ) is without an addition of poly(acrylic acid) (abbreviated as PAA), and ( b ) is with an addition of 3 vol % FAA according to the present invention, respectively.
FIGS. 3 ( a ) and ( b ) are photographs showing green bodies of bone cement pastes (TTCP/DCPA:CSH=35/65, 0.60 M (NH 4 ) 2 HPO 4 , L/P=0.33 cc/g) injected into Hanks' solution, wherein ( a ) is without an addition of poly(acrylic acid) (abbreviated as PAA), and ( b ) is with an addition of 3 vol % PAA according to the present invention, respectively.
FIGS. 4 ( a ) and ( b ) are photographs showing green bodies of bone cement pastes (TTCP/DCPA:CSH=45/55, 0.60 M (NH 4 ) 2 HPO 4 , L/P=0.33 cc/g) injected into Hanks' solution, wherein ( a ) is without an addition of poly(acrylic acid) (abbreviated as FAA), and ( b ) is with an addition of 3 vol % PAA according to the present invention, respectively.
DETAILED DESCRIPTION OF THE INVENTION
Embodiment(s) of the present invention is a calcium-based bone cement formula with an enhanced non-dispersive ability, which is applicable to various medical fields, such as orthopedic, spinal, and dental surgeries. The calcium-based bone cement formula of the present invention has convenient working time and setting time to form a hardened block with high strength, excellent biocompatibility and superior osteoconductivity.
A process for preparing bone cement paste, in one embodiment, comprises mixing powder component with setting liquid component by a mixing mechanism such as agitation. The powder component, for example, may include mixture of calcium sulfate source and calcium phosphate source. Alternatively, calcium sulfate source and calcium phosphate source can be separate powders. In this case, calcium sulfate source and calcium phosphate source are combined first to form a power mixture prior to mixing with setting liquid component.
The calcium sulfate source and calcium phosphate source discussed earlier can be tetracalcium phosphate (TTCP) and/or dicalcium phosphate anhydrous (DCPA) powders. It should be noted that other types of sources can be used as long as they have similar chemical properties or characteristics as TTCP and/or DCPA.
The bone cement paste, in one embodiment, becomes hard or cured within a period of setting time under an atmosphere environment or an environment surrounded by body fluid such as blood. During an operation, an operator or doctor places bone cement paste into a hole or cavity at a damaged bone via a suitable tool through an incision. For example, for an orthopedic, spinal or root canal treatment, when bone cement paste becomes or cures into hardened bone cement composite in-situ, the hardened bone cement will be resorbed by the subject body over time in accordance with a predefined bioresorption rate.
The bone cement paste, in one embodiment, can be injected into a bone hole or cavity through a thin tube or with an orthopedic paste delivering tool such as a conventional medical instrument described in U.S. Pat. No. 7,325,702 B2, in which the paste will form a block of hardened bone cement. It should be noted that an orthopedic delivering tool is able to continually deliver the paste into a bone cavity until the cavity is filled.
The following examples via experimental procedures are illustrative and are intended to demonstrate embodiments of the present invention, which, however, should not be taken to limit the embodiments of the invention to the specific embodiments, but are for explanation and understanding only, since numerous modifications and variations will be apparent to those skilled persons in this art.
EXPERIMENTAL PROCEDURES
Abbreviation
TTCP: tetracalcium phosphate
DCPA: dicalcium phosphate anhydrous
CSH: calcium sulfate hemihydrate
WT: Working time
ST: Setting time
L/P ratio: Liquid/powder ratio
Chemicals Used for the Study
Manu- Loca- Chemical Formula facturer tion Tetracalcium Ca 4 (PO 4 ) 2 O Fabricated Taiwan phosphate (TTCP) in-house Dicalcium CaHPO 4 ACROS New phosphate jersey, anhydrous (DCPA) USA Calcium sulfate CaSO 4 •½H 2 O Showa Tokyo, hemihydrate (CSH) Japan Diammonium (NH 4 ) 2 HPO 4 Showa Tokyo, hydrogen phosphate Japan Poly(acrylic acid) —(CH 2 —C(COOH)H) n — Showa Tokyo, Japan
Preparation of TTCP Powder
The TTCP powder was fabricated in-house from the reaction of dicalcium pyrophosphate (Ca 2 P 2 O 7 ) (Sigma Chem. Co., St. Louis, Mo., USA) and calcium carbonate (CaCO 3 ) (Katayama Chem. Co., Tokyo, Japan) using the method suggested by Brown and Epstein [ Journal of Research of the National Bureau of Standards—A Physics and Chemistry 6 (1965) 69A 12].
TTCP powder was prepared by mixing Ca 2 P 2 O 7 powder with CaCO 3 powder uniformly for 12 hours. The mixing ratio of Ca 2 P 2 O 7 powder to CaCO 3 powder was 1:1.27 (weight ratio) and the powder mixture was heated to 1400° C. to allow two powders to react to form TTCP.
Preparation of a TTCP/DCPA/CSH Composite Paste
Appropriate amounts of TTCP and DCPA powders were uniformly mixed in a ball miller, followed by uniformly mixing with appropriate amount of CSH powder. The resultant TTCP/DCPA/CSH mixed powders were mixed uniformly with a desirable setting solution (e.g., 0.6M (NH 4 ) 2 HPO 4 ) at a desirable LAP ratio (e.g., 0.28 ml/g) to form a TTCP/DCPA/CSH paste.
Preparations of TTCP/DCPA, TTCP/CSH and TTCP/DCPA:CSH Powder Components
Appropriate amounts of TTCP and CSH powders were uniformly mixed in a ball miller to obtain a powder component of TTCP/CSH. TTCP and DCPA powders were uniformly mixed in a ball miller in a molar ratio of 1:1 to obtain a powder component of TTCP/DCPA. Appropriate amounts of the resulting TTCP/DCPA mixed powder and CSH powder were uniformly mixed in a ball miller to obtain a powder component of TTCP/DCPA:CSH. The weight ratios of TTCP, DCPA and CSH of the TTCP/DCPA:CSH powder components used in following examples of the present application are listed as follows, wherein TTCP and DCPA mixed are in a molar ratio of 1:1:
TTCP/DCPA:CSH TTCP:DCPA:CSH (by weight) (by weight) 90:10 2.69:1:0.41 85:15 2.69:1:0.65 80:20 2.69:1:0.92 75:25 2.69:1:1.23 65:35 2.69:1:1.99 55:45 2.69:1:3.02 45:55 2.69:1:4.51 35:65 2.69:1:6.85 25:75 2.69:1:11.07 10:90 2.69:1:33.21
Preparations of Setting Liquid Components
Poly(acrylic acid) (abbreviated as PAA) has a molecular weight of 150,000 and was obtained as 25 wt % aqueous solution (reagent grade, Showa, Japan). Diammonium hydrogen phosphate [(NH 4 ) 2 HPO 4 ] solutions of different concentrations were used to prepare (NH 4 ) 2 HPO 4 solutions having different volume percentages of the PAA aqueous solution by mixing the (NH 4 ) 2 HPO 4 solutions separately with the PAA aqueous solution as-received in different volume ratios, expressed as “PAA conc in setting soln (vol %)” in the Tables of the following examples.
Working Time/Setting Time Measurement
The working time of cement paste was determined by the time after that the cement paste was no longer workable. The setting time of cement paste was measured according to the standard method set forth in ISO 1566 for dental zinc phosphate cements. The cement is considered set when a 400 gm weight loaded onto a Vicat needle with a 1 mm diameter tip fails to make a perceptible circular indentation on the surface of the cement.
Dispersion Behavior Evaluation
A cement paste was prepared by mixing a powder component and a setting liquid component with a desired liquid to powder ratio (ml/g) for one minute, and then the paste was immediately injected into a Hanks' solution bath at 37° C. via a 5 ml syringe. The injected cement paste green body in the Hanks' solution was observed to determine its dispersion behavior.
Severity Level of Dispersion Upon Contact with Water:
1—Negligible
2—Mild
3—Extensive
4—Extremely severe
Example 1. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “65:35” Composite Cement Paste Prepared from 0.45 M (NH 4 ) 2 HPO 4 Setting Solution with L/P Ratio of 0.35 ml/g
A cement paste was prepared by mixing the TTCP/DCPA:CSH=65:35 powder component with 0.45 M (NH 4 ) 2 HPO 4 setting solution containing various volume percentages of PAA and with a L/P ratio of 0.35 ml/g, and dispersion behavior and working/setting time of the resulting paste were evaluated. The results and the contents of PAA are listed in the following Table 1.
TABLE 1 TTCP/DCPA:CSH = 65:35, 0.45M (NH 4 ) 2 HPO 4 , L/P ratio of 0.35 ml/g PAA conc PAA conc Severity index in setting in paste WT/ST of paste Powder soln (vol %) (wt %)* (Min) dispersion 65:35 — 0 11.5/13.3 3 65:35 0.25 0.018 11.4/13.8 2 65:35 0.5 0.036 11.2/14.4 1 65:35 5.0 0.355 9.4/13.0 1 65:35 7.0 0.497 9.3/12.8 1 65:35 10.0 0.709 9.2/13.1 1 *PAA conc in paste (wt %): percentage of PAA based on the total weight of the cement paste
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula. (2) WT/ST significantly decreases as PAA concentration>5 vol % in solution.
Example 2. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “65:35” Composite Cement Paste Prepared from 0.45 M (NH 4 ) 2 HPO 4 Setting Solution with L/P Ratio of 0.30 ml/g
This example was conducted similarly as in Example 1 except that L/P ratio was changed from 0.35 ml/g to 0.30 ml/g. The results and the contents of PAA are listed in the following Table 2.
TABLE 2 TTCP/DCPA:CSH = 65:35, 0.45M (NH 4 ) 2 HPO 4 , L/P ratio of 0.30 ml/g PAA conc PAA conc Severity index in setting in paste WT/ST of paste Powder soln (vol %) (wt %)* (Min) dispersion 65:35 — 0 10.3/12.8 4 a) 65:35 0.5 0.032 9.5/11.9 2 65:35 1.0 0.063 9.5/11.9 1 b) 65:35 3.0 0.190 6.7/8.7 1 65:35 5.0 0.316 6.5/8.5 1 *same as in Table 1. a),b) Photographs of the injected green bodies of the cement pastes in Hanks' solution are shown in FIG. 1 (a) and (b), respectively.
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula. (2) WT/ST significantly decreases as PAA concentration>3 vol % in solution.
Example 3. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “65:35” Composite Cement Paste Prepared from 0.60 M (NH 4 ) 2 HPO 4 Setting Solution with L/P Ratio of 0.33 ml/g
A cement paste was prepared by mixing the TTCP/DCPA:CSH=65:35 powder component with 0.60 M (NH 4 ) 2 HPO 4 setting solution containing 3 vol % of PAA with a L/P ratio of 0.33 ml/g, and dispersion behavior and working/setting time of the resulting paste were evaluated. In this example, some of the cement pastes prepared were added with a magnesium-containing compound, which was added to the powder component prior to mixing with the setting solution.
MgSO 4 purchased from Showa (Japan) was ground and filtered with a sieve with a mesh number of 200, so that sizes of the particles were controlled at about 0.074 mm.
MgO purchased from Showa (Japan) was ground by ball milling with two times of the weight of the MgO of alumina milling balls (diameter of 10 mm) in a 500 ml plastic bottle for two hours.
Mg 3 (PO 4 ) 2 was prepared by heating Mg 3 P 2 O 8 .8H 2 O purchased from Sigma-Aldrich (Germany) in an oven at 500° C. for three hours to remove the crystalline water.
For the cement pastes further containing a magnesium-containing compound, 30 g of the TTCP/DCPA:CSH=65:35 powder component, 60 g of alumina milling balls (diameter of 10 mm), and a desired amount of the powder of the magnesium-containing compound were added into a 500 ml plastic bottle, and the resulting mixture was ball milled for one day.
The results and the contents of PAA are listed in the following Table 3.
TABLE 3 TTCP/DCPA:CSH = 65:35, 0.60M (NH 4 ) 2 HPO 4 , L/P ratio of 0.33 ml/g PAA conc in PAA conc Severity index setting soln in paste WT/ST of paste Powder (vol %) (wt %)* (Min) dispersion 65:35 — 0 8.5/10.3 3 a) 65:35 3.0 0.203 6.0/7.9 1 b) 65:35 + 0.25% 3.0 0.203 15.4/17.7 1 MgSO 4 65:35 + 0.5% 3.0 0.203 14.7/17.0 1 MgSO 4 65:35 + 1% 3.0 0.203 14.4/16.5 1 MgSO 4 65:35 + 0.5% 3.0 0.203 5.9/8.2 1 Mg 3 (PO 4 ) 2 65:35 + 1.0% 3.0 0.203 13.8/16.1 1 Mg 3 (PO 4 ) 2 65:35 + 0.5% 3.0 0.203 11.5/13.9 1 MgO 65:35 + 1.0% 3.0 0.203 11.7/14.3 1 MgO *same as in Table 1. a),b) Photographs of the injected green bodies of the cement pastes in Hanks' solution are shown in FIG. 2 (a) and (b), respectively.
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula. (2) WT/ST significantly decreases as PAA concentration>3 vol % in solution. (3) As small amounts of MgSO 4 , Mg 3 (PO 4 ) 2 or MgO are further added, the PAA-induced decrease in WT/ST is recovered.
Example 4. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “65:35”, “35:65” and “45:55” Composite Cement Pastes Prepared from 0.60 M (NH 4 ) 2 HPO 4 Setting Solution with LIP Ratios of 0.30, 0.33 and 35 ml/g
In this example the cement pastes were prepared with 0.60 M (NH 4 ) 2 HPO 4 setting solution and various powder components, and LIP ratios as indicated in the following Table 4, wherein the severity index of paste dispersion is for each cement paste is also listed.
TABLE 4 TTCP/DCPA:CSH = 65:35, 35:65 and 45:55, 0.60M (NH 4 ) 2 HPO 4 , L/P ratios of 0.30, 0.33 and 35 ml/g PAA conc PAA conc Severity index* in setting in paste L/P WT/ST of paste Powder soln (vol %) (wt %)* (ml/g) (Min) dispersion 65:35 — 0 0.30 8.5/10.3 3 65:35 3.0 0.189 0.30 5.7/7.2 1 35:65 — 0.35 8.4/9.3 3 a) 35:65 0.5 0.035 0.35 9.0/10.5 2 35:65 1.0 0.071 0.35 9.4/10.3 2 35:65 3.0 0.212 0.35 10.5/11.2 1 b) 35:65 — 0.33 7.8/8.8 4 35:65 3.0 0.203 0.33 7.5/8.8 1 45:55 — 0.35 10.5/12.8 4 45:55 1.0 0.071 0.35 10.9/13.0 2 45:55 3.0 0.212 0.35 4.2/6.5 1 45:55 — 0.30 5.8/7.9 4 45:55 1.0 0.063 0.30 6.3/8.5 2 45:55 3.0 0.189 0.30 4.0/6.4 1 *Same as in Table 1 a),b) Photographs of the injected green bodies of the cement pastes in Hanks' solution are shown in FIG. 3 (a) and (b), respectively.
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula.
Example 5. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “45:55” Composite Cement Paste Prepared from 0.60 M (NH 4 ) 2 HPO 4 Setting Solution with L/P Ratio of 0.33 ml/g
In this example some of the cement pastes prepared were added with a magnesium-containing compound similarly as in Example 3.
TABLE 5 TTCP/DCPA:CSH = 45:55, 0.60M (NH 4 ) 2 HPO 4 , L/P ratio of 0.33 ml/g PAA conc in PAA conc Severity index* setting soln in paste WT/ST of paste Powder (vol %) (wt %)* (Min) dispersion 45:55 — 0 8.8/10.5 4 a) 45:55 1.0 0.068 9.7/11.8 2 45:55 3.0 0.203 4.1/6.2 1 b) 45:55 + 0.5% 3.0 0.203 15.7/18.3 1 MgSO 4 45:55 + 1.0% 3.0 0.203 11.3/13.5 1 MgSO 4 45:55 + 0.5% 3.0 0.203 14.3/16.5 1 Mg 3 (PO 4 ) 2 45:55 + 0.5% 3.0 0.203 11.5/14.5 1 MgO *Same as in Table 1 a),b) Photographs of the injected green bodies of the cement pastes in Hanks' solution are shown in FIG. 4 (a) and (b), respectively.
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula. (2) WT/ST significantly decreases as PAA concentration>3 vol % in solution. (3) As small amounts of MgSO 4 , Mg 3 (PO 4 ) 2 or MgO are further added, the PAA-induced decrease in WT/ST is recovered.
Example 6. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “85:15” Composite Cement Paste Prepared from 0.0375 M (NH 4 ) 2 HPO 4 Setting Solution with L/P Ratio of 0.25 ml/g
In this example a setting solution of 0.0375 M (NH 4 ) 2 HPO 4 containing 1 vol % of PAA was used to evaluate the effect on the dispersion behavior. The conditions and results are listed in the following Table 6.
TABLE 6 TTCP/DCPA:CSH = 85:15, 0.0375M (NH 4 ) 2 HPO 4 , L/P ratio of 0.25 ml/g PAA conc PAA conc Severity index* in setting in paste WT/ST of paste Powder soln (vol %) (wt %)* (Min) dispersion 85/15 — 0 — 4 85/15 1.0 0.056 — 2 *Same as in Table 1
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as a small amount of PAA is introduced into the formula.
Example 7. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “TTCP/DCPA” Cement Paste Prepared from 0.0375M (NH 4 ) 2 HPO 4 Setting Solution
In this example setting solutions of 0.0375 M (NH 4 ) 2 HPO 4 containing small amounts of PAA were used to evaluate the effect on the dispersion behavior. The conditions and results are listed in the following Table 7.
TABLE 7 TTCP/DCPA = 1:1 (mole), 0.0375M (NH 4 ) 2 HPO 4 TTCP/ PAA conc in PAA conc Severity in- DCPA setting soln in paste L/P WT/ST dex* of paste Powder (vol %) (wt %)* (ml/g) (Min) dispersion 1:1 (mole) — 0 0.28 10.4/13.0 3 1:1 (mole) 0.5 0.030 0.28 9.4/11.0 2 1:1 (mole) 2.0 0.121 0.28 8.6/9.9 1 1:1 (mole) — — 0.26 10.1/12.2 3 1:1 (mole) 0.5 0.029 0.26 8.3/9.6 2 1:1 (mole) 1.0 0.057 0.26 7.7/9.3 1 1:1 (mole) — — 0.24 6.7/8.0 4 1:1 (mole) 0.5 0.027 0.24 5.2/6.6 2 1:1 (mole) 1.0 0.054 0.24 5.4/6.6 2 *Same as in Table 1
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula.
Example 8. Effect of PAA Concentration on Dispersion Behavior of TTCP/CSH=45:35 Cement Paste Prepared from 0.45 M and 0.60 M (NH 4 ) 2 HPO 4 Setting Solutions with L/P Ratios of 0.35 and 0.30 ml/g
TTCP powder and CSH powder were mixed thoroughly in a ratio of 45:35 by weight, and to the resulting powder mixture (NH 4 ) 2 HPO 4 setting solutions containing various volume percentages of PAA were added according to L/P ratios as listed in the following Table 8. The dispersion behavior of the resulting pastes were evaluated. The conditions and results are listed in the following Table 8.
TABLE 8 TTCP/CSH = 45:35, 0.45M and 0.60M (NH 4 ) 2 HPO 4 , L/P ratios of 0.35 and 0.30 ml/g PAA conc Severity in setting PAA conc L/P index* (NH 4 ) 2 HPO 4 soln in paste ratio of paste TTCP:CSH (M) (vol %) (wt %) (ml/g) dispersion 45:55 0.45 — 0 0.35 4 45:55 0.45 1.0 0.071 0.35 1 45:55 0.45 3.0 0.213 0.35 1 45:55 0.45 — 0 0.35 4 45:55 0.45 3.0 0.190 0.30 1 45:55 0.60 — 0 0.30 4 45:55 0.60 3.0 0.189 0.30 1 *Same as in Table 1
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula.
Example 9. Effect of PAA Concentration on Dispersion Behavior and Working/Setting Time of “TTCP” Cement Paste Prepared from 0.0375M (NH 4 ) 2 HPO 4 Setting Solution with L/P Ratio of 0.33 ml/g
TTCP powder and 0.0375 (NH 4 ) 2 HPO 4 setting solution containing various volume percentages of PAA were mixed with a L/P ratio of 0.33. The dispersion behavior and working/setting time of the resulting pastes were evaluated. The conditions and results are listed in the following Table 9.
TABLE 9 TTCP, 0.0375M (NH 4 ) 2 HPO 4 , L/P ratio of 0.33 ml/g PAA conc PAA conc Severity index* in setting in paste WT/ST of paste Powder soln (vol %) (wt %) (Min) dispersion TTCP — 0 6.6/7.9 4 TTCP 2.0 0.138 6.3/7.7 3 TTCP 5.0 0.344 — 2
Results:
(1) The severity of cement paste dispersion in water dramatically decreases as small amounts of PAA are introduced into the formula.
Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention except as and to the extent that they are included in the accompanying claims. Many modifications and variations are possible in light of the above disclosure.
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A calcium-based bone cement formula having a powder component and a setting liquid component with a liquid to powder ratio of 0.20 ml/g to 0.50 ml/g is provided, wherein the powder component includes tetracalcium phosphate. The bone cement formula further contains, based on the total weight of the bone cement formula, 0.01-1% of poly(acrylic acid) having a repeating unit of —(CH 2 —C(COOH)H)n-, wherein n=50-50000.
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BACKGROUND OF THE INVENTION
This is a continuation of application Ser. No. 280,151, filed Aug. 14, 1972, now abandoned.
The present application is a continuation-in-part of copending application Ser. No. 59,339, filed July 29, 1970, now abandoned, in favor of a continuation application Ser. No. 242,218, filed Apr. 7, 1972.
FIELD OF THE INVENTION
The present invention relates to, in general, topical deodorant compositions and, in particular, to deodorant compositions to be applied to the skin. More particularly, the invention is directed to novel, topical deodorant compositions containing, as an active perspiration odor reducer or retarder, an effective amount of a biological protease-inhibitor.
Description of the Prior Art
Perspiration, or sweat, is the clear liquid exuded from or excreted by the sudoriparous glands. It possesses a characteristic odor, and a salty taste; its reaction is normally alkaline, but, when mixed with sebum, it is acid. It contains sodium chloride, cholesterin, fats, and fatty acids and traces of albumin, urea, and other compounds.
The perspiration or sweat, in combination with skin bacteria, provide a suitable medium for the elaboration and production of biological proteases or proteolytic enzymes further contributing to the odor caused by perspiration.
Cosmetic preparations whish have a perspiration odor-reducing or retarding effect are well-known. Many substances of different chemical compositions have, heretofore, been suggested for use as materials capable of reducing or retarding the odor of perspiration. Among such substances may be mentioned, for example, 2,2'-methylene-bis-( 3,4,6-trichlorophenol), chlorinated diphenyl ureas, such as, 3,4,4'-trichlorocarbanilide, 1.6di-4-chlorophenyl-diquanidohexane, hydroxy benzoic acid methyl ester halogenated phenols, such as, bis-(hydroxy-3,5-dichlorophenyl) sulphide, as well as other bacteriostatic materials, such as, for example, antibiotics.
Many of the aforementioned substances, however, exhibit characteristics which detract from their value as deodorants and militate against their extended use because they are not well tolerated by the human body and induce undesirable side effects, such as, skin irritation, eczema allergies, and the like. Additionally, many of such substances of the prior art have the disadvantage of forming strong acid solutions which can cause damage to clothing and delicate fabrics.
DESCRIPTION OF THE INVENTION
The present invention contemplates improved topical compositions of matter containing biological protease-inhibitors which, when applid to the living skin, effectively reduce or retard the odor caused by perspiration.
The biological protease-inhibitors which find utility in the manufacture of the improved topical compositions of the invention as deodorants include protease-inhibitors as, for example, kallikrein-trypsin-inhibitors from pancreas, liver, lung, lymph glands, parotid glands, spleen and blood serum and protease-inhibitors of vegetable origin, for example the inhibitors from potatoes [A. K. Balls, C. A. Ryan, J. Biological Chem. 238, 2976 (1963)] and leguminous plants.
Biological protease-inhibitors, such as kallikrein-inhibitors, are readily available by the methods and procedures described, for example, in U.S. Pat. No. 3,181,997 and U.S. Pat. No. 3,558,773.
In the compositions of the invention, the concentration of the biological protease-inhibitor is not necessarily a critical feature of the invention and can be varied over a wide range. It has been found, however, that 0.1 to 5.0 weight percent solutions of the biological protease-inhibitors incorporated into the deodorant compositions provide compositions suitable as deodorants with immediate and lasting effects. Particularly suitable compositions comprise aqueous solutions containing from about 0.1 to 1.0 weight percent of the biological protease-inhibitor. Such solutions will provide at least a concentration on the skin area, for deodorizing purposes, of 0.1 ml. per cm 2 . As the compositions of the invention are amenable for use in forms other than aqueous solutions, such as, creams, ointments, lotions, aerosol sprays, stick pencils, soaps, and the like, similar dosages or concentrations of the biological protease-inhibitors therein are to be observed. In preparing such formulations, standard manufacturing processes can be employed. Typical processes for formulating various cosmetic preparations are illustrated in Chemie-Lexikon, 6th Edition, Vol. 1, Col. 1402 and 1403 (H. Rompp).
It is to be understood that the biological protease-inhibitors can be used alone or in combinations with one another to obtain, in some cases, a synergistic effect. Also, it is to be understood that other ingredients can be incorporated into the compositions to obtain a product having properties from a purely cosmetic aspect. Further, if desired, various bacteriostatic and germicidal agents may be added to the compositions of the invention. The use of such additives is optional and, while contemplated in the commercial practice of the invention, their presence is not essential to the deodorizing function of the compositions of the invention.
The efficacy of the various compositions of the invention as deodorants was demonstrated in many series of experiments and demonstrated that they possessed strong deodorizing action without undesirable side effects. In a typical experiment, a swatch of cloth moistened with a solution containing 1.5 weight percent of a biological protease-inhibitor, such as, kallikrein-inhibitor, was placed in one armpit and a comparable swatch moistened with distilled water was placed in the other armpit overnight. Upon subsequent examination and observation, it was found that the swatch moistened with the aqueous solution containing the biological protease-inhibitor remained completely odorless, while the swatch of cloth moistened with distilled water possessed a distinct odor of sweat.
The following examples will serve to illustrate the various forms in which the invention can be utilized and the utility thereof in maintaining and/or enhancing the odor reducing or retarding effects of the compositions when applied to the living body in the sweat producing areas, such as the armpits of a person.
EXAMPLE 1
A small piece of cloth was immersed into an aqueous solution containing 1.5 weight percent of kallikrein-trypsin inhibitor and the cloth, thus dampened, was placed into the armpit of a human test subject and, by way of comparison, an equivalent piece of cloth, dampened with distilled water, was placed into the opposite armpit and both pieces left overnight.
Prior to placing both pieces of dampened cloth into their respective armpits, they are examined visually and sniffed for odor and found to be visually identical and odorless. Subsequently, both pieces were removed and examined visually and tested for odor. The piece of cloth that had been dampened with an aqueous solution of kallikrein-trypsin inhibitor was odorless while the piece of cloth dampened with distilled water had a definite odor of sweat when sniffed to detect same.
EXAMPLE 2
An emulsified base for a deodorant body cream is prepared comprising the following ingredients:
a. 60 grams of a non-organic emulsifier;
b. 70 grams of paraffin oil;
c. 50 grams of neutral oil;
d. 10 grams of Purcellin liquid; and
e. 310 grams of water.
The above ingredients are mixed and emulsified at a temperature of 70°C. and the resultant emulsion cooled to a temperature of 45°C. Subsequently, the emulsion is combined with a solution of the biological protease inhibitor isolated from potatoes and 400 grams of water and the entire mass further emulsified to form a deodorant cream mixture.
Application of the deodorant cream mixture to the armpits of human subjects in a manner similar to Example 1, above, provides similar results.
Similar results are also obtained by substituting in the above formulation the kallikrein-trypsin inhibitor for the biological protease inhibitor derived from potatoes.
EXAMPLE 3
A deodorant soap is prepared, in accordance with the invention, by mixing together 1000 grams of flakes of soap having a palm nut fatty acids-coconut fatty acids base and 30 grams of pelletized biological protease inhibitor derived from potatoes. After thorough mixing, the mixture is divided and pressed into cakes of soap.
Washing and bathing by human subjects with the deodorant cakes of soaps prepared above provides results similar to those of Example 1.
Similar results are also obtained by substituting in the above formulation the kallikrein-trypsin inhibitor for the biological protease inhibitor derived from potatoes.
EXAMPLE 4
A deodorant stick or pencil is prepared by heating together at a temperature of 80°C.:
a. 500 grams of propylene glycol; and
b. 125 grams of Isonon liquid 70%. The mixture is allowed to cool to a temperature of 45°C. and combined with a solution of 20 grams of the biological protease inhibitor derived from potatoes in 285 grams of water. The resultant mixture is cast into forms of pencil bodies and cooled.
Subsequent application of the deodorant pencil sticks prepared above to the armpits of human subjects provides results similar to those observed in Example 1.
Similar results are also obtained by substituting in the above formulation the kallikrein-trypsin inhibitor for the biological protease inhibitor derived from potatoes.
While the invention has been described in detail above, it is apparent that it is capable of numerous modifications and embodiments without departing from the essential spirit and character thereof. Thus, the scope of the invention is not intended to be limited by the specific disclosure above but only as defined by the subjoined claims.
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A method of reducing body odor by applying to the body an aqueous odor-reducing composition containing a perspiration odor-reducing or retarding amount of a biological protease-inhibitor.
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FIELD OF THE INVENTION
[0001] This invention is directed to delivery devices for delivering subcutaneous cavity marking devices. More particularly, the delivery device may be used with biopsy systems permitting efficient placement of a biopsy marker within a cavity. The device may include an intermediate member which assists in deployment of the marking device. The device may also include a deployment lock to prevent premature deployment of a biopsy marker. The invention may further include the capability to match an orientation of a biopsy probe that has been rotated upon procurement of a biopsy sample.
BACKGROUND OF THE INVENTION
[0002] Over 1.1 million breast biopsies are performed each year in the United States alone. Of these, about 80% of the lesions excised during biopsy are found to be benign while about 20% of these lesions are malignant.
[0003] In the field of breast cancer, stereotactically guided and percutaneous biopsy procedures have increased in frequency as well as in accuracy as modem imaging techniques allow the physician to locate lesions with ever-increasing precision. However, for any given biopsy procedure, a subsequent examination of the biopsy site is very often desirable. There is an important need to determine the location, most notably the center, as well as the orientation and periphery of the subcutaneous cavity from which the lesion is removed.
[0004] In those cases where the lesion is found to be benign, for example, a follow-up examination of the biopsy site is often performed to ensure the absence of any suspect tissue and the proper healing of the cavity from which the tissue was removed. This is also the case where the lesion is found to be malignant and the physician is confident that all suspect tissue was removed and the tissue in the region of the perimeter of the cavity is “clean”.
[0005] In some cases, however, the physician may be concerned that the initial biopsy failed to remove a sufficient amount of the lesion. Such a lesion is colloquially referred to as a “dirty lesion” or “having a dirty margin” and requires follow-up observation of any suspect tissue growth in the surrounding marginal area of the initial biopsy site. Thus, a re-excision of the original biopsy site must often be performed. In such a case, the perimeter of the cavity must be identified since the cavity may contain cancerous cells. Moreover, the site of the re-excised procedure itself requires follow-up examination, providing further impetus for accurate identification of the location of the re-excised site. Therefore, a new marker may be placed after re-excision.
[0006] While biopsy markers are well known, examples of improved biopsy markers are described in U.S. patent application Ser. No. 09/285,329 entitled “SUBCUTANEOUS CAVITY MARKING DEVICE AND METHOD” and 09/347,185 entitled “SUBCUTANEOUS CAVITY MARKING DEVICE AND METHOD” each of which is incorporated by reference herein. Placement of such biopsy markers may occur through either invasive surgical excision of the biopsy, or minimally invasive procedures such as fine needle aspiration or vacuum assisted biopsy.
[0007] In a fine needle aspiration biopsy, a small sample of cells is drawn by a thin needle from the lump or area of suspect tissue. If the suspect area or lump cannot be easily felt, non-invasive imaging may be used to help the doctor guide the needle into the right area. A core biopsy is similar to a fine needle aspiration biopsy, except that a larger needle is used. Under a local anaesthetic, the doctor makes a very small incision in the patient's skin and removes several narrow sections of tissue from the suspect area of tissue through the same incision. The core biopsy provides a breast tissue sample rather than just individual cells. Thus making it easier for the pathologist to identify any abnormalities.
[0008] Vacuum-assisted biopsy is performed through the skin and may rely upon ultrasound or stereotactic guidance to determine the location of a suspect area of tissue. Two commonly used vacuum-assisted breast biopsy systems are Mammotome® supplied by Johnson & Johnson Ethicon Endo-surgery or MIBB® supplied by Tyco International. Examples of such devices may be found in U.S. Pat. No. 5,526,822 entitled “Methods and Apparatus for Automated Biopsy and Collection of Soft Tissue,” U.S. Pat. No. 5,649,547 entitled “Methods and Devices for Automated Biopsy and Collection,” U.S. Pat. No. 6,142,955 entitled “Biopsy Apparatus and Method” and U.S. Pat. No. 6,019,733 entitled “Biopsy Apparatus and Method” the entirety of each of which is incorporated by reference herein. Such breast biopsy systems include a probe that is inserted through the skin and is usually adapted to provide a vacuum to assist in obtaining the biopsy sample.
[0009] FIGS. 1 A- 1 D illustrate an exemplary biopsy probe 10 . As illustrated, the distal ends of probes 10 of these biopsy systems are adapted to both penetrate tissue and to contain a cutting member 12 which facilitates the removal of the biopsy sample. The cutting member 12 will contain an aperture 14 (often referred to as a “probe window.”) The aperture 14 may be located on a side of a probe 10 .
[0010] Once inserted through the skin, the cutting member 12 of the probe 10 aligns with suspect tissue 1 via stereotactic, ultrasound, or other means. After proper positioning of the probe 10 , a vacuum draws the breast tissue 1 through the probe aperture 14 into the probe 10 . As illustrated in FIG. 1B, once the tissue 1 is in the probe 10 , the cutting member 12 actuates to capture a tissue sample 3 . The tissue sample 3 may then be retrieved through the probe 10 to a tissue collection area (e.g., a standard pathology tissue cassette). FIG. 1C illustrates the probe 10 after the tissue sample is cleared from the aperture 14 . Note that the illustration depicts a portion of the cutting member 12 as being retracted, leaving aperture 14 open; the cutting member 12 may alternatively be placed in a closed position during retrieval of the tissue sample.
[0011] The biopsy system is often adapted such that the cutting member 12 and aperture 14 rotate (e.g., via manipulation of a thumbwheel on the probe or biopsy system) with respect to the biopsy system. After excision of a tissue sample from the area of suspect tissue, the radiologist or surgeon may rotate the probe 10 and the aperture 14 to a new position relative to the biopsy system. FIG. 1D illustrates the probe 10 and aperture 14 after being rotated but without being removed from the body. The rotation of the probe 10 and aperture 14 permits excision of multiple subsequent biopsy samples from a target area of suspect tissue with only a single insertion of the biopsy probe 10 . It should be noted that FIG. 1D is provided merely to illustrate the rotation of the probe 10 within the body. As such, the placement of biopsy markers is not illustrated in the figure. Moreover, the cutting member 12 is depicted in a closed position. This may ease rotation of the probe 10 within the tissue.
[0012] The entire cycle may be repeated until sampling of all desired areas occurs (typically, 8 to 30 samples of breast tissue are taken up to 360 degrees around the suspect area). Accordingly, it is important that the operator of the biopsy system is able to identify the orientation of the probe aperture 14 relative to the biopsy system at any given time while the probe aperture 14 remains within the tissue. Often, demarcations on the thumbwheel permit the identification of the probe orientation.
[0013] The above described removal of tissue samples creates tissue cavities. Hence, for reasons that are apparent to those familiar with such biopsy procedures, placement of a biopsy marker through the probe is most desirable. For example, repeated removal of the probe and insertion of a biopsy marking device may cause unneeded additional discomfort to the patient undergoing the procedure; removal of the probe may introduce error in placement of the biopsy marker into the desired location; repeated removal and insertion of each of the devices may prolong the duration of the procedure or spread cancer cells; after the probe removes a tissue sample, it is in the optimal location to deposit a marker; etc.
[0014] Biopsies may be performed with other tissue sampling devices as described in U.S. Pat. Nos. 4,699,154; 4,944,308, and 4,953,558 the entirety of each of which is incorporated by reference herein. Such devices obtain a biopsy sample through a hollow biopsy needle having an aperture located in a distal end of the biopsy needle. As with the biopsy devices previously described, once the tissue sampling devices removes tissue and creates a biopsy cavity, it may be desirable to place a marker in the area of the biopsy cavity.
[0015] In view of the above, there remains a need for an improved biopsy marker delivery system that may facilitate placement of a biopsy marker and also may be used with commercially available biopsy systems.
SUMMARY OF THE INVENTION
[0016] This invention relates to delivery systems for delivery of biopsy cavity marking devices. A basic variation of the invention includes a tissue marker delivery device comprising a tube having a lumen extending therethrough, a tissue marker removably seated in a distal end of the tube, a rod slidably located within the tube lumen and having a first end extending through a proximal end of tube and a second end in the tube lumen; and an intermediate member separating the rod from the biopsy marker, where advancement of the rod in a distal direction displaces the intermediate member to displace the tissue marker from said marker seat. In a variation of this invention, the intermediate member is discrete from both the rod and the tissue marker. The intermediate member may comprises a flexible covering as described herein.
[0017] Another variation of the invention includes a delivery device for use with a biopsy probe having an aperture, the delivery device comprising a body having proximal and distal ends and a passageway extending therethrough, an elongate sheath having a lumen extending therethrough, the sheath extending distally from the distal end of the body, the sheath lumen in fluid communication with the body passageway, an access tube having a proximal and a distal end and a lumen extending from at least a portion of the access tube through the proximal end, the access tube slidably located within the body passageway and the sheath lumen, a marker seat located towards the distal end of the access tube, a rod slidably located within the access tube lumen and having a first end extending through the proximal end of the body and a second end in communication with the marker seat, wherein advancement of the rod in a distal direction advances the marker seat distally until the marker seat is adjacent to the probe aperture such that a marker in the marker seat may be deployed from the aperture. For example, when using a biopsy probe having an aperture in a side wall of the probe, the marker seat may be advanced within the aperture and subsequently deploys a marker. When the inventive device is used with biopsy probes having an aperture in a distal end of the probe, the marker seat may be advanced just proximal to the aperture in preparation for subsequent deployment of the marker.
[0018] The rod may advance the marker seat through a number of configurations. For example, the rod may be sized to have an interference fit with a portion of the access tube lumen. Another example includes a device configured such that the rod engages a marker which is situated in the marker seat. In such a case, a sheath may restrain the marker in the marker seat. Thus, until the marker is no longer constrained by the sheath, the rod will advance the marker within the sheath. In another variation, the rod may be in communication with a fluid that is itself in communication with the marker seat. In such a case, the rod may apply a force on the fluid to advance the marker seat and/or displace a marker from the marker seat. In some variations, the fluid may serve to displace a flexible covering out of the marker seat. It is contemplated that the rod of the present invention may advance the marker seat through a combination of configurations either described herein or known to those familiar with similar delivery devices.
[0019] A variation of the invention also includes a delivery device as described above, wherein the body further comprises a keyway along the passageway, and the body has an orientation being defined relative to the keyway, the delivery device further comprising an access tube key located on the access tube and adapted to be slidably located within the body keyway, the access tube key adapted to maintain an orientation of the access tube with the body orientation.
[0020] Variations of the invention may also include a deployment lock having a first end and a second end, the first end moveably located in the body and the second end located outside of the body, the first end adapted to engage a portion of the rod to prevent at least distal movement of the rod, whereupon disengagement of the first end of the deployment lock from the portion of the rod permits distal movement of the rod. The deployment lock may be removable from the device or may be moveable within the device so as to permit disengagement of the lock from the rod while still being attached to the body of the device.
[0021] The invention also may include a rod stop fixedly located on the rod, wherein after the rod is advanced into the marker seat, the rod stop engages the access tube stop preventing further distal movement of the rod. The rod stop may also include a rod key that is adapted to maintain an orientation of the rod with the body orientation.
[0022] A variation of the device includes an access tube stop fixedly located on a portion of the access tube being located within the body, wherein advancement of the rod in a distal direction advances the marker seat distally until the access tube stop engages the distal end of the body preventing further distal movement of the access tube whereupon further distal advancement of the rod advances into the marker seat. In one variation of the invention, engagement of the access tube stop against the distal end of the body places the marker seat adjacent to the biopsy probe aperture.
[0023] In another variation of the invention a portion of the distal end of the access tube is removed to define the marker seat. The invention may also include a covering located over at least the marker seat, where at least a portion of the covering is adapted to displace into and out of the marker seat. Movement of the rod into the marker seat displaces the covering out of the marker seat. In variations of the invention using such a covering, there is no direct contact between the actuator (e.g., rod, etc.) and a marker placed within the marker seat.
[0024] In another variation of the invention, the inventive device includes a delivery device key adapted to seat in the biopsy probe and maintain an orientation of the access tube with an orientation of the biopsy probe. The delivery device key may be located on the elongated sheath or on the body of the device. In some variations of the invention, seating the delivery device key in the biopsy probe will cause a distal end of the outer sheath to be placed immediately proximal to the biopsy probe aperture.
[0025] Variations of the invention also may include a biopsy marker that is seated in the marker seat.
[0026] Although the delivery device and method described herein for delivering a marking device to a subcutaneous cavity is suited for use with a biopsy probe, the invention is not necessarily limited as such. Variations of the inventive device may be used with any type of biopsy procedure.
[0027] The invention also contains a kit containing a biopsy marker delivery device as described herein and an introducer cannula. The introducer cannula may be used to facilitate insertion of the delivery device into the patient to assist in delivery of a biopsy marker. The kit may also include a biopsy probe. The biopsy probe may be a spring-loaded biopsy probe.
[0028] The invention also includes a method for marking a biopsy cavity. In one variation, the inventive method includes using a delivery device having a marker, a tube removably seating the marker, a rod within the tube, and an intermediate member separating the rod and the marker, the method comprising, advancing the marker and delivery device to the biopsy cavity, actuating the rod to displace the intermediate member on the delivery device; and depositing the marker in the cavity upon displacing the intermediate member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] [0029]FIG. 1A illustrates biopsy probe for use with variations of the present invention.
[0030] [0030]FIG. 1B illustrates the biopsy probe of FIG. 1A in which tissue is drawn through an aperture of the probe for excision of a biopsy sample.
[0031] [0031]FIG. 1C illustrates the biopsy probe of FIG. 1A where the biopsy sample is cleared from the aperture.
[0032] [0032]FIG. 1D illustrates the biopsy probe of FIG. 1A rotated within the body.
[0033] [0033]FIG. 2 provides a perspective view of a variation of a delivery device of the present invention.
[0034] FIGS. 3 A- 3 K illustrate various components that may be used in delivery devices of the present invention.
[0035] FIGS. 4 A- 4 C provide cross sectional views of a portion of a delivery device of the present invention during actuation of the device.
[0036] FIGS. 5 A- 5 D illustrate cross sectional views of a delivery device of the present invention deploying a marker.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The following discussion of the variations of the invention and the reference to the attached drawings are for explanatory purposes and do not exhaustively represent the possible combinations and variations of the invention. Those skilled in the art will readily appreciate that many variations may be derived using the following description. The following examples are intended to convey certain principles of the invention. These examples are not intended to limit the scope of the claims to any particular example. It is understood that the claims are to be given their broadest reasonable interpretation in view of the description herein, any prior art, and the knowledge of those of ordinary skill in the field. Furthermore, it is understood that the invention is not limited to the markers described herein. Instead, the invention may be used with any type of biopsy marker or tissue marker.
[0038] [0038]FIG. 2 illustrates a perspective view of a variation of a biopsy marker delivery device 20 of the present invention. In this variation, the delivery device 20 includes a body 22 having an elongate sheath 28 extending from a distal end 24 of the body 22 and a rod 30 extending from a proximal end 26 of the body 22 . This variation of the device 20 also includes a deployment lock 32 having a first end 34 moveably located in the body 22 of the device 20 and second end 36 located outside of the body 22 . As discussed below, the first end 34 of the deployment lock 32 engages a portion (not shown) of the rod 30 preventing distal movement of the rod. Disengagement of the first end 34 of the deployment lock 32 from the rod 30 permits movement of the rod 30 within the device 20 .
[0039] As will be apparent, the device 20 may incorporate features to permit ease in handling the device 20 . For example, the proximal ends of the body 22 and the rod 30 each may have portions 40 , 42 of increased surface area that assist in the ability to actuate the device. Also, the second end 36 of the deployment lock may have raised surface areas 44 that permit an operator to grip the deployment lock 32 when an operator disengages the first end 34 of the deployment lock 32 from the rod 30 . Such features, which permit ease in handling the device, are well known to those skilled in the art and are not meant to limit the scope of the invention.
[0040] [0040]FIG. 3A illustrates a cross sectional view of a body 22 and elongate sheath 28 of a variation of the inventive device. In this variation, the body 22 has a proximal end 26 , a distal end 24 , and a passageway 46 extending through the body 22 . The variation of the body 22 depicted in FIG. 3A also contains a keyway 48 extending through at least a portion of the body passageway 46 . As described below, the keyway 48 permits alignment and/or maintaining orientation of components of the inventive device with an orientation of the body 22 . The ability to identify an orientation of the device relative to, for example, a biopsy probe is desirable for proper deployment of a biopsy marker. The keyway 48 may be a male or female keyway which permits mating of a corresponding key such that a component having such a key will maintain orientation while moved through the device.
[0041] In the variation depicted in FIG. 3A, the distal end 24 of body 22 includes an end component 50 that reduces a diameter of the passageway 46 therethrough. It should be noted that the body 22 may be optionally designed without such an end component 50 . For example, the body 22 could be designed as a unitary piece. In variations where the body 22 is constructed as a unitary piece, the body passageway 46 may optionally have an area of reduced diameter at the distal end 24 . This area of reduced diameter made from a uniform reduction of the diameter of the passageway 46 or may have one or more protrusions which effectively reduce the diameter of the passageway 46 . The body 22 may also include an opening 52 through which a deployment lock may be inserted through the body 22 . As discussed above, the body 22 may also include a portion 40 of increased surface area that permits handling of the device. The body may be formed out of materials such as ABS, polycarbonate, acetal, or acrylic.
[0042] The inventive device also includes an elongate sheath 28 extending distally from a distal end 24 of the body 22 . The elongate sheath 28 contains a lumen (not shown) that extends through the sheath 28 . The sheath lumen is in fluid communication with the body passageway 46 . By fluid communication, it is meant that the passageways merely intersect or join one another. The elongate sheath 28 may be flexible such that the sheath 28 may be advanced to a biopsy site, either through a device, such as a biopsy probe, cannula, etc., or through a biopsy tract created by the biopsy procedure. In any case, variations of the invention may include sheaths 28 that may have sufficient rigidity to access the biopsy cavity (in some cases the sheath 28 may even contain a reinforcing member, e.g., a braid, stiffening member.) The sheath may comprise materials such as polyethylene (PE), especially high density PE (HDPE), nylon, urethane, or a fluoropolymer.
[0043] A variation of the inventive device, as illustrated in FIG. 3A, may also contain a delivery device key 38 . The delivery device key 38 may be located on the elongated sheath 28 (as illustrated) or may be located on the body 22 . As discussed above, it may be necessary to rotate a biopsy probe to retrieve multiple tissue samples. The delivery device key 38 is adapted to be seated into a biopsy probe (not shown) such that when the biopsy probe is rotated, an orientation of the device may match the orientation of the aperture of the biopsy probe. The delivery device key 38 may include a raised protrusion or other surface which may mate with a portion of the biopsy probe. In some variations of the inventive device, the length of the elongate sheath 28 is selected such that when the delivery device key 38 is engaged in a biopsy probe, the distal end of the elongate sheath 28 is located adjacent to an aperture of the biopsy probe.
[0044] [0044]FIG. 3B illustrates a cross sectional view of a variation of a deployment lock 32 of the inventive device. The deployment lock 32 includes a first end 34 and a second end 36 . The first end 34 of the deployment lock 32 is adapted to be inserted into the device body and to engage a portion of a rod (as illustrated below) to at least prevent the rod from distal movement through the device. Thus, “locking” the device. The second end 36 of the deployment lock 32 may be located outside of the device body and is adapted to permit disengagement of the deployment lock 32 from the rod. For example, the variation of the deployment lock 32 depicted in FIG. 3B is adapted to be removed from the device via pulling the second end 36 of the deployment lock 32 . While this variation of the deployment lock 32 is designed to be removed from the device, variations of deployment locks of the present invention may remain within the device while simultaneously disengaging from a rod to permit movement of the rod. Additionally, variations of the deployment lock 32 may also contain one or more securing arms 51 , which assist in retention of the deployment lock 32 in a “locked” position.
[0045] [0045]FIG. 3C illustrates a side view of a rod 30 of the present invention. The rod 30 may be a tubular or other member. The rod 30 may have a lumen extending therethrough. The rod 30 may be flexible as required to navigate through a sheath which may itself be located in a biopsy probe. Some materials from which the rod may be constructed include nylon, urethane, PE, and fluoropolymers. As discussed above, the rod 30 may have a portion 42 of increased surface area or increased diameter at a proximal end or along any length of the rod 30 . The rod 30 also includes a rod stop 54 located along a length of the rod 30 . FIG. 3D illustrates a cross sectional view of the rod stop 54 taken along the line 3 D- 3 D of FIG. 3C. As shown in FIG. 3D, variations of the rod stop 54 may include a rod key 56 . The rod key 56 is adapted to mate with the body keyway to maintain the orientation of the rod with respect to the device. Although the rod key 56 depicted in FIG. 3D is a male key, the rod key 56 is intended to mate with the corresponding keyway. Accordingly, the rod key 56 may be a female rather than male fitting. Furthermore, the rod key 56 of the present invention is not limited to placement on the rod stop 54 . For example, variations of the inventive device may include a rod key which may be located on a rod 30 as opposed to the rod stop 54 .
[0046] [0046]FIG. 3E illustrates a side view of a variation of an access tube 58 of the present invention. The access tube 58 comprises proximal 68 and distal ends 70 with a lumen 72 extending at least from a portion of the tube 58 through the proximal end 68 . In some variations of the invention, the lumen may extend throughout the tube. However, the lumen may also be closed at a distal end 70 such that when a biopsy marker (not shown) is placed in a marker seat 62 , the biopsy marker is prevented from advancing distally within the access tube. This is especially useful when side ejection of a marker is desired. In such a case, the closed distal end 70 prevents a marker from remaining within a portion of the lumen 72 of the tube 58 at the distal end 70 . The distal end 70 may be either closed or have a occluding member placed therein. The access tube 58 may be flexible as required by the procedure being used to access a biopsy cavity. The access tube 58 may be constructed from materials such as nylon, urethane, PE, or a fluoropolymer.
[0047] As illustrated in FIG. 3E, the access tube may also include an access tube stop 60 . In this variation, the access tube stop 60 is located at the proximal end 68 of the access tube 58 . However, the invention is not limited as such as the access tube stop 60 may be located over any portion of the access tube 58 . FIG. 3F illustrates a cross-sectional view of the access tube stop 60 of FIG. 3E as taken along lines 3 F- 3 F. In this variation the access tube stop 60 also contains an access tube key 66 . As discussed above, the access tube key 66 mates with a body keyway such that the access tube 58 and marker seat 62 are able to maintain a desired orientation within the device. The access tube key 66 may be male or female depending upon the body keyway.
[0048] The access tube 58 will contain a marker seat 62 located towards a distal end 70 of the tube 58 . The marker seat 62 will be adapted depending upon the biopsy marker used with the device. For example, a marker seat 62 may be formed by removing a portion of the access tube 58 . In some variations of the invention, the invention may have an intermediate member that separates the biopsy marker from the actuating member of the device (e.g., the rod, etc.) and ejects/deploys the marker from the device. The intermediate covering may be discrete from the tube and tissue marker, e.g., a flexible covering 64 as described below. However, it is also contemplated that a portion of the tube itself could be configured to serve as the intermediate member (e.g., a weakened section of a tube that is adapted to fold into the tube lumen to seat the marker and unfold from the lumen to deploy the marker.)
[0049] As described above, a variation of the invention includes an intermediate member that is a flexible covering 64 . The flexible covering 64 may be located over a portion of the tube 58 which includes the marker seat 62 . FIG. 3G illustrates a cross-sectional view of the marker seat 62 taken along the line 3 G- 3 G of FIG. 3E. FIG. 3G illustrates the marker seat 62 covered by the flexible covering 64 . As shown, at least a portion of the flexible covering 64 is placed or folded into the marker seat 62 . In such variations, the flexible covering 64 assists in deployment of the marker as the flexible covering 64 may be displaced and/or unfolded out of the marker seat 62 . In any case, when a flexible covering is used, there may be no contact between any actuator (e.g., rod, etc.) and marker. The flexible covering may be made from any commercially available medical grade flexible material such as polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), or FEP.
[0050] [0050]FIG. 3E also illustrates a rod 30 slidably located within the access tube 58 where a distal end of the rod 30 may be located adjacent to the marker seat 62 . Distal advancement of the rod 30 advances the access tube 58 within the device. In one variation, the distal end of the rod 30 may be urged against a marker (not shown) seated in the marker seat 62 . Since the marker will be constrained within the marker seat, which is located within an elongate sheath (not shown), the marker will be unable to deploy from the marker seat 62 . Accordingly, as a result of the rod 30 pushing against the marker (constrained within the marker seat 62 ) the access tube 58 and marker seat 62 advance with the rod 30 . Once the marker is no longer constrained by a sheath, e.g., the marker and marker seat are either placed within or advanced out of an aperture of the biopsy probe, then the force of the rod 30 applied against the marker will eject the marker from the marker seat 62 .
[0051] In another variation, the distal end of the rod 30 and the lumen 72 of the access tube 58 may be sized such to provide a friction fit between the lumen 72 and the rod 30 . Thus, the friction fit permits the rod 30 to advance the access tube 58 until the access tube 58 meets with sufficient resistance to permit the rod 30 to advance independently of the access tube 58 . In any case, advancement of the rod 30 in a distal direction advances the marker seat 62 distally until the marker seat 62 is adjacent to the probe aperture such that a marker located in the marker seat 62 may be ejected from the probe aperture.
[0052] The invention includes variations where the rod advances the marker seat through a combination of configurations either described herein or known to those familiar with similar delivery devices.
[0053] [0053]FIG. 3H illustrates a side view of a portion of the access tube 58 of FIG. 3E. In this illustration, the rod 30 is able to advance independently of the access tube 58 and advances into the marker seat 62 . As a result, the rod 30 displaces and/or unfolds the flexible covering 64 out of the marker seat 62 . Although not illustrated, this action permits the deployment of the marker (not shown) seated within the marker seat 62 . In those variations of the invention not having a flexible covering 64 , the rod 30 may deploy the marker via direct contact. In such cases, the distal end of the rod 30 is adapted to assist in deploying the marker (e.g., the distal end of the rod may be tapered, rounded, hinged to eject the marker, etc.) Variations of the invention also include a marker seat that permits deployment of a marker through a distal opening in the lumen of the elongate sheath.
[0054] [0054]FIG. 31 illustrates another variation of the present invention. In this variation, a rod 30 is slidably located within the access tube 58 where a distal end 76 of the rod 30 is adjacent to a fluid 74 . In this variation, distal advancement of the rod 30 also advances the access tube 58 within the device when a marker (not shown) is constrained in the marker seat 62 by an outer sheath (not shown.) Such a result occurs as advancement of the rod 30 displaces the fluid 74 . Because the marker is constrained in the marker seat 62 , the fluid 74 cannot displace the flexible covering 64 from the marker seat 62 . Instead, the force on the fluid 74 applied by the distal end 76 of the rod 30 acts to distally advance the marker seat 62 and marker out of the sheath. Once the marker is advanced out of the sheath and is no longer constrained, the force applied by the distal end 76 of the rod 30 displaces the fluid 74 which displaces the flexible covering 64 thereby ejecting the marker from the marker seat 62 .
[0055] [0055]FIG. 3J illustrates a state of the device after the marker is freed from constraint by the sheath. As illustrated, the displacement of the fluid 74 by the distal end of the rod 76 displaces the flexible covering 64 from the marker seat 62 to eject the marker. As illustrated in FIGS. 3I and 3J, the distal end 76 of the rod 30 may be adapted such that it forms a seal (e.g., through sizing, use of a sealing gasket, etc.) with the lumen 72 of the access tube 58 .
[0056] In some variations of the invention the rod 30 may be entirely replaced with fluid. In such a case, a syringe or similar apparatus would provide an actuator/pressure source to displace the fluid and deploy the marker. Moreover, the flexible covering 64 may also be fluid-tight such that the fluid cannot escape from the device. For example, FIGS. 3I and 3J show the flexible covering 64 as having fluid tight seals 78 . It is noted that the position of the seals 78 , as illustrated, is merely for exemplary purposes as the seals may be placed in any position such that fluid does not escape. As is apparent, in most cases, the distal end 70 of the access tube 58 will be sealed to prevent leakage of the fluid 74 . In some cases, the distal end 70 may be adapted to deliver or leak the fluid in a controlled manner. The fluid 74 may be any biocompatible liquid or gas, e.g., saline fluid, air, etc. In some cases, as the rod 30 exerts a force on the fluid 74 , the fluid may compress 74 . In such cases, it may become necessary to add additional fluid 74 to the device.
[0057] [0057]FIG. 3K illustrates a variation of an access tube 58 for use with the present invention. As illustrated, the distal end 70 of the access tube 58 may be tapered to permit the access tube 58 to enter a cavity where tissue has collapsed or narrowed the tract entering the cavity.
[0058] It should be noted that the rod 30 and access tube 58 of the present invention may be sufficiently flexible to navigate through a biopsy probe, cannula, etc., to access a biopsy site. However, some applications may require variations of the invention having a rigid access tube and rod.
[0059] [0059]FIG. 4A illustrates a cross sectional view of a portion of a variation of inventive delivery device 20 . As illustrated, the device 20 is in a “locked” position as the deployment lock 32 engages a portion of the rod 30 to prevent at least distal movement of the rod 30 . In this variation, a first end 34 of the deployment lock 32 engages a rod stop 54 on a rod 30 . Although the deployment lock 32 may be removed from the body 22 , variations of the invention contemplate that the deployment lock 32 may disengage from the rod 30 while remaining attached to the body 22 . As mentioned above, in variations of the device 20 for use with a biopsy probe (not shown), the device may have a delivery device key (not shown) as well. The delivery device key permits the orientation of the device to match the orientation of the probe aperture as it is rotated within the body of a patient. Moreover, the delivery device key may be placed such that the distal end of the elongate sheath 28 is placed adjacent to the probe aperture when the delivery device key is engaged to the biopsy probe.
[0060] [0060]FIG. 4B illustrates a cross sectional view of a portion of the variation of the inventive delivery device 20 where the deployment lock (not shown) is removed from the body 22 via an opening 52 in the body 22 . As a result, the rod 30 is able to be advanced in a distal direction within the device 20 . As described above, advancement of the rod 30 permits advancement of a access tube 58 within the device 20 . As illustrated in FIG. 4B, once an access tube stop 60 engages a distal end 24 of the body 22 , the access tube 58 is prevented from further distal movement. Therefore, once the access tube 58 advances out of a distal end of the elongated sheath 28 , the access tube stop 60 engages the distal end 24 of the body 22 preventing further distal movement. However, the access tube 58 advances sufficiently to permit advancement of the marker seat out of the distal end of the sheath 28 . In some variations of the inventive device 20 , the body 22 may also contain a keyway (not shown) as discussed above. Accordingly, the access tube 58 will contain a corresponding key which permits the orientation of the access tube to match the orientation of the device. Maintaining this orientation may also permit the marker seat to be oriented within the device 20 such that it is aligned with an aperture of a probe to permit deployment of the marker through the probe aperture.
[0061] In variations of the invention not having an access tube stop 60 , distal movement of the rod 30 advances the marker seat distally due to the distal end of the rod pushing against a marker within the marker seat. Since the marker is constrained by the sheath and/or biopsy probe, it remains within the marker seat. Once the marker is advanced out of the sheath 28 and is placed adjacent to the probe-aperture, it is no longer constrained by the sheath 28 or the biopsy probe. At this point, further distal movement of the rod 30 ejects the now unconstrained marker from the marker seat through the probe aperture and into a biopsy cavity.
[0062] [0062]FIG. 4C illustrates a cross sectional view of the device 20 of FIG. 4B where the rod 30 is further distally advanced to deploy a marker. In this variation, the rod contains a rod stop 54 which limits the distal advancement of the rod 30 . Accordingly, the device 20 will be configured such that the rod 30 is able to deploy the marker prior to being prevented from further distal advancement.
[0063] FIGS. 5 A- 5 B illustrate a partial cross sectional view of a variation of a delivery device of the present invention for use with a biopsy probe 10 . FIG. 5A illustrates the inventive delivery device after the access tube 58 is advanced out of the elongate sheath 28 . As discussed above, the elongate sheath 28 may be placed immediately adjacent to an aperture 14 of the probe 10 and the access tube 58 is advanced within the aperture 14 . Also as discussed above, the device may permit orientation of the components of the device with the aperture 14 of the probe 10 .
[0064] [0064]FIG. 5B illustrates the invention where the rod 30 may move independently of the access tube 58 . In variations of the device having a marker 100 seated in the marker seat 62 upon a flexible covering 64 , distal movement of the rod 30 may force the flexible covering 64 out of the marker seat 62 thereby deploying the marker 100 .
[0065] [0065]FIG. 5C illustrates the use of the inventive device used with a probe 10 that contains a distal aperture 14 (e.g., a biopsy needle, etc.) In this case, the device is advanced out of the aperture 14 so that the marker 100 maybe deployed in a biopsy cavity. FIG. 5D illustrates another variation of the inventive device where a distal end 70 of the rod 30 permits advancement of the device through a tissue tract (the channel leading from the biopsy cavity to the outside of the patient's body which is created during the biopsy procedure) that may constrict in diameter. It is noted that the sheath 28 may also be adapted to facilitate advancement through a narrowed tissue tract. For instance, if a biopsy probe is removed from the site, the device illustrated in FIG. 5D may be solely advanced into the tissue tract to deposit the biopsy marker 100 . Furthermore, the device illustrated in FIG. 5D may be used with a biopsy probe as shown in FIG. 5C.
[0066] From the foregoing, it is understood that the invention provides an improved biopsy marker delivery system. While the above descriptions have described the invention for use in the marking of biopsy cavities made through a vacuum-assisted breast biopsy procedure, the invention is not limited to such. The invention disclosed herein may be used with any biopsy procedure discussed herein or otherwise known.
[0067] The invention herein has been described by examples and a particularly desired way of practicing the invention has been described. However, the invention as claimed herein is not limited to that specific description in any manner. Equivalence to the description as hereinafter claimed is considered to be within the scope of protection of this patent.
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An apparatus for delivering subcutaneous cavity marking devices. More particularly, the delivery devices may be used with biopsy systems permitting efficient placement of a biopsy marker within a cavity. The device may include an intermediate member which assists in deployment of the marking device. The devices may also include a deployment lock to prevent premature deployment of a biopsy marker. The invention may further include the capability to match an orientation of a biopsy probe which has been rotated upon procurement of a biopsy sample.
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FIELD OF THE INVENTION
The present invention relates to a composite logic circuit and particularly to a double-triggered logic circuit.
BACKGROUND OF THE INVENTION
Nowadays, digital systems are increasingly diversified. How to reduce power consumption of chipsets is a one of main research focuses. Digital synchronous systems usually have one or more sets of clock systems. Clock signals are used to control data movement. The clock system consists of a clock system distribution network and a flip-flop. It consumes greatest power in the chipset. Power consumption can be divided into static power consumption and dynamic power consumption. The dynamic power consumption can be divided into switch power consumption and short circuit current power consumption. The static power consumption mostly is leakage power consumption.
The technique for reducing power can target reducing static power and reducing dynamic power. As the dynamic power consumption always is much greater than the static power consumption, design of circuits mainly focuses on reducing the dynamic power consumption. The most effective approach to reduce power consumption is lowering operation voltage. But lowering the voltage often results in lower speeds. Another alternative is adopting a double-edge trigger design. It can reduce power without decreasing throughput. Thus in practice of circuit design a pulse triggered flip-flop is adopted to reduce system clock loading capacitance and power consumption.
Refer to FIGS. 1 and 2 for the structure of a conventional flip-flop. It includes two latches. Clock signals have a positive edge and a negative edge to control data sampling and holding activities. Referring to FIG. 1 , the master latch 1 performs data sampling and the slave latch 2 performs data holding. When in use, data is moved from a data input end (Din) 3 to a data output end (Qout) 4 in sync with an edge signal at a clock signal input end (Clock) 5 . A positive edge triggered mode only samples a positive edge signal of the data input end (Din) 3 from the clock signal input end (Clock) 5 , and a negative edge triggered mode samples a negative edge signal of the data input end (Din) 3 from the clock signal input end (Clock) 5 . Then the data transmission can be accomplished. Thus every complete transaction of data transmission requires two clock signals.
Refer to FIG. 2 for the time series of the flip-flop shown in FIG. 1 . A clock signal 6 has a positive edge to sample a data 7 and a negative edge to hold a data 8 . Such a phenomenon creates a race trough problem. Hence a time factor that maintaining the flip-flop in normal duty conditions has to be taken into account.
The conventional double edge trigger flip-flop (hereafter is referred to as DETFF) requires only one clock signal 6 to complete the entire transaction of data transmission. A typical DETFF can save data at the positive edge or negative edge of the clock signal. But the transmission delay is longer. The driven loading capacitance at the clock signal input end (Clock) 5 also is greater. Although the clock signal input end (Clock) 5 at the positive edge or negative edge can save data, the original clock signal at the clock signal input end (Clock) 5 must have a double frequency to become a new clock signal. Hence the clock frequency used on the DETFF is one half of the clock frequency of the ordinary single edge triggered flip-flop. But a same data transmission rate can be achieved. As power consumption is proportional to the operational clock frequency, the consumed power also is lower. Hence DETFF is frequently adopted on power reducing designs.
Compared with the single edge triggered flip-flop, the DETFF has a more complex structure and requires a greater chipset size to contain more internal nodes and capacitor exchanging. And it results in the benefit of reducing the frequency is offset.
To address the aforesaid issues other techniques have been developed, such as explicit-pulsed-triggered flip-flop and implicit-pulsed-trigger flip-flop. Both of them can be further divided into a single-edge pulse triggered type and a double-edge pulse triggered type. When the explicit-pulsed-triggered flip-flop is adopted on multiple and serial-and-parallel circuits the pulse generator can be shared, but not so for the implicit-pulsed-trigger flip-flop. Hence total power consumption is much lower when the explicit pulsed-triggered flip-flop is adopted. However, in a serial-and-parallel environment a greater loading capacitance occurs that could result in not able to generate the pulses. As a result, the explicit-pulsed-triggered flip-flop does not provide as much benefits as the implicit-pulsed-trigger flip-flop does. Moreover, with addition of the pulse generator on the circuit, power consumption increases. The implicit-pulsed-trigger flip-flop also has a higher average duty frequency than the explicit-pulsed-triggered flip-flop.
As the pulse-triggered flip-flop provides a less complicated circuit design, it is increasingly accepted in applications of registers. The pulse generator has another important feature, namely control of its operation mode. The traditional pulse generator operates only in one mode. Refer to FIG. 3 for a conventional dual-mode logic circuit. It has a MUX circuit 9 A to control two logic circuits, one is a AND logic circuit 9 B and another is a XNOR logic circuit 9 C. A mode selection signal input E is sent to the MUX circuit 9 A as a transmission mode selection signal. Such a logic circuit requires a great number of transistors. Although the circuit is simpler, the loading capacitance of the clock signal input (CLK) 9 D is greater and huge power consumption is caused.
On technical development for the design of lower power, multiple duty modes often is a requirement for single-pulse triggered or double-pulse triggered. For instance, at the stage of data synchronization on a data communication circuit, effective duty frequency can be doubled through the double-edge triggered mode. Once the stage of data synchronization is accomplished, the circuit can be switched to single-edge triggered to reduce the power consumption by the effective clock. It the past such a design usually requires pulse generators of two different modes. The single-edge pulse triggered circuit often includes an inverter and an AND or an OR logic gate to generate a positive or negative pulse signal. The double-edge pulse triggered circuit often includes an inverter and a XNOR logic gate and a XOR logic gate, and another MUX circuit to do selections.
On CMOS circuits of the conventional logic circuits, such as those for applications of XOR, XNOR, AND, OR and MUX, the circuits are relatively simple, but they have the problem of threshold voltage loss. The problem of threshold voltage loss is because circuits cannot function at a low voltage and consume a greater amount of power. Such a problem creates other problems on the circuits such as not adequate driving power and short circuit current. In short, adopted the conventional techniques to make a customized circuit are time-consuming and take great efforts. It requires a lot of time to design, execute, customize features and perform integration. There is a need for an improved circuit to provide desired time series specifications, minimum power consumption and enhanced processing speed.
SUMMARY OF THE INVENTION
Therefore the primary object of the present invention is to provide a double-triggered logic circuit that consists of two types of logic circuits and is structured at a lower complexity.
Based on the foregoing object the double-triggered logic circuit of the invention aims to connect a clock signal input end and a clock delay signal input end. It includes a first PMOS transistor, a second PMOS transistor, a first NMOS transistor, a second NMOS transistor and a third PMOS transistor.
The first PMOS transistor is connected to a mode selection signal input E and the clock delay signal input end. The second PMOS transistor is connected to the first PMOS transistor and the clock signal input end. The first NMOS transistor is connected to the first PMOS transistor. The second NMOS transistor is connected to the clock signal input end A and coupled with the third PMOS transistor. The second PMOS transistor, the first NMOS transistor, the second NMOS transistor and the third PMOS transistor are connected to generate an output signal.
By means of the structure set forth above, the double-triggered logic circuit of the invention can provide the following advantages:
1. The logic circuit thus formed has a logic gate consisting of a smaller number of transistors, thus electronic elements are fewer and complexity is lower and the loading capacitance of the clock system is reduced. Hence power consumption is greatly reduced. Furthermore, by adopting the dual operation mode, it is not limited to single usage but can meet requirements of wider applications.
2. To provide a simpler circuit design, the invention has no path of grounding power supply. Hence there is no significant short circuit current during switch of the transistors and no power consumption occurs. Operation difference of XNOR and AND logic circuits is used to control mode selection, so that the MUX circuit adopted in the conventional techniques can be omitted. As a result, the time delay is further reduced and power-delay-product (hereafter is referred to as PDP) also is lower.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying embodiments and drawings. The embodiments discussed below serve only for illustrative purpose and are not the limitations of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a conventional flip-flop.
FIG. 2 is a schematic view of the time series of a conventional master-slave flip-flop.
FIG. 3 is a schematic view of a conventional dual-mode logic circuit.
FIG. 4 is a circuit diagram of the double-triggered logic circuit of the invention.
FIG. 5 is a truth table of an AND and a XNOR.
FIG. 6 is an AND/XNOR logic circuit diagram designed according to the truth table of an AND and a XNOR.
FIG. 7 is a circuit diagram to overcome threshold voltage loss.
FIG. 8 is a circuit diagram of a double-pulse triggered flip-flop formed according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The related details and techniques of the invention is further described as the following embodiments. The embodiments are used to illustrate the invention but not to limit practices of the invention.
Please referring to FIG. 4 , the invention, a double-triggered logic circuit, provides a connection between a clock signal input end A and a clock delay signal input end B. It includes a first PMOS transistor P 1 , a second PMOS transistor P 2 , a first NMOS transistor N 1 , a second NMOS transistor N 2 and a third PMOS transistor P 3 .
The first PMOS transistor P 1 has a source connecting to a mode selection signal input E and a gate connecting to the clock delay signal input end B. The second PMOS transistor P 2 has a source connecting to a drain of the first PMOS transistor P 1 and a gate connecting to the clock signal input end A. The first NMOS transistor N 1 has a gate connecting to the gate of the first PMOS transistor P 1 . The second NMOS transistor N 2 has a gate connecting to the clock signal input end A and also is coupled with the third PMOS transistor P 3 . The drains of the second PMOS transistor P 2 and the first NMOS transistor N 1 and the sources of the second NMOS transistor N 2 and the third PMOS transistor P 3 are connected to generate an output signal.
In front of the clock delay signal input end B there is at least one first inverter 10 . In an embodiment of the invention three sets of the first inverter 10 are provided to connect to the third PMOS transistor P 3 .
Also refer to FIG. 5 for the truth table of an AND and a XNOR. To reduce the circuit complexity, based on the truth table of an AND and a XNOR, when both the clock signal input end A and the clock delay signal input end B are “0” at the same time, output of the AND is “0” and output of the XNOR is “1”. Such a difference can be used to control the selection of the mode selection signal input E.
Refer to FIG. 6 for an AND/XNOR logic circuit adopted FIG. 5 . It does not have a direct power supply grounding path. Hence during switch of transistors, no obvious short current occurs to consume power. The circuit shown in FIG. 6 also does not have the conventional MUX circuit 9 A shown in FIG. 3 . Hence the time delay is reduced, and the PDP is lower. But it still has drawbacks. Referring to FIGS. 5 and 6 , when the clock signal input end A, clock delay signal input end B and mode selection signal input end E have respectively input signals “000, 011 and 111”, output still has the problem of threshold voltage loss. The conditions “011 and 111” take place during the clock positive edge is “0→1” when the circuit is adopted on a pulse generator. Referring to FIG. 7 , such a problem can be overcome by adding a second inverter 20 and a transistor 30 . It aims to resolve the problem of threshold voltage loss. If the circuit is adopted on a pulse generator (which not shown in the drawings), when the clock signal input end A, clock delay signal input end B and mode selection signal input end E have respectively an input signal EAB of “000, the circuit does not generate a pulse signal. Hence the input signal does not affect the circuit of the pulse generator. Therefore upon connecting to the pulse generator, since the pulse wave is narrower, the power consumption caused by short current also is lower. Thus there is no problem of threshold voltage loss.
Referring to FIGS. 4 and 7 , the second inverter 20 in FIG. 7 can be replaced by the first inverter 10 shown in FIG. 4 . In practice, the dual-mode logic circuit can be formed with five transistors as shown in FIG. 4 . The invention, by having three sets of first inverter 10 to provide clock delay function and incorporating with the circuit shown in FIG. 7 , can form the dual-mode logic circuit depicted in FIG. 4 . The Boolean algebra formula of the circuit is as follow:
F=Ē ( A⊕B )+ E ( A+B )
EMBODIMENT EXAMPLES
Referring to FIGS. 5 and 8 , a clock input signal CLK, a clock delay input signal CLKD and mode selection signal input E 1 shown in FIG. 8 are to map the clock signal input end A, clock delay signal input end B and mode selection input signal E shown in FIG. 5 . The circuit diagram is for a double-pulse mode triggered flip-flop formed according to the invention. Circuit operation is as follow:
(1) When the mode selection signal input E 1 is “1” (double-edge pulse triggered generation mode):
a. Both the clock input signal CLK and clock delay input signal CLKD are “0” (the clock input signal CLK is at a lower edge): a first transistor MP 1 and a second transistor MP 2 are in an ON condition, and generate a pulse signal “1” to set on a latch 40 . Data is transmitted from a data input end 50 to a data output end 60 ; b. When both the clock input signal CLK and clock delay input signal CLKD are “1” (the clock input signal CLK is at an upper edge): a third transistor MN 1 , a fourth transistor MN 2 and a fifth transistor MP 3 are in an ON condition, and generate the pulse signal “1” to set on the latch 40 . Data is transmitted from the data input end 50 to the data output end 60 ; c. When the clock input signal CLK and clock delay input signal CLKD are “01” or “10” (the clock input signal CLK is fixed: the third transistor MN 1 or fourth transistor MN 2 is in an “ON” condition and the pulse signal is “0” (no pulse generated), the latch 40 maintains the voltage at the data output end 60 through a circuit feedback function of a third inverter 70 .
(2) When the mode selection signal input E 1 is “0” (single-edge pulse triggered generation mode):
a. Both the clock input signal CLK and clock delay input signal CLKD are “0” (the clock input signal CLK is at a lower edge): the first transistor MP 1 and second transistor MP 2 are in an ON condition, and the pulse signal is “0” (no pulse generated); the latch 40 maintains the voltage at the data output end 60 through the circuit feedback function of the third inverter 70 ; b. When both the clock input signal CLK and clock delay input signal CLKD are “1” (the clock input signal CLK is at an upper edge): the third transistor MN 1 , the fourth transistor MN 2 and the fifth transistor MP 3 are in an ON condition, the pulse signal is 1″ (a pulse generated), and the latch 40 is set on. Data is transmitted from the data input end 50 to the data output end 60 ; c. When the clock input signal CLK and clock delay input signal CLKD are “01” or “10” (the clock input signal CLK is fixed: the third transistor MN 1 or the fourth transistor MN 2 is “ON” and the pulse signal is “0” (no pulse generated), the latch 40 maintains the voltage at the data output end 60 through the circuit feedback function of the third inverter 70 .
As a conclusion, the double-triggered logic circuit provided by the invention employs AND/XNOR logic modules and can support two types of pulse triggered modes: a single-edge triggered mode and a double-edge triggered mode. It can save transistor number and layout size, and achieve high speed operation and consume less power, thus is adaptable to a wide scope of applications and offers significant improvement over the conventional techniques.
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A double-triggered logic circuit is a composite circuitry consisting of a plurality of PMOS, NMOS, inverters and a signal line. It includes an AND logic circuit and a XNOR logic circuit to generate an adjustable pulse mode to solve the problem of threshold voltage loss.
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BACKGROUND OF THE INVENTION
The invention pertains to a self-drilling blind tension rivet which includes a rivet casing with a stop flange and a rivet spindle on one end of which a drilling unit is provided, and at other end region of which at least one rotation and tension force application element is provided to apply force by rotation and tensioning of a tool for drilling and setting the blind tension rivet.
Self-drilling blind rivets have already become known in various designs. For example, a self-drilling blind rivet is known from DE-A-2,554,557, where the rivet spindle or shank has over its entire length two parallel surfaces that extend along the spindle where the rivet casings or sleeves have surfaces complimentary to the surface of the spindle, in order to achieve a torsion-locked connection between the rivet spindle and the rivet casing. On the one hand, a special construction of the rivet casing is recruited, whereby the rivet spindle and the rivet casing must be precisely tailored to fit each other. On the other hand, immediately upon setting of the rivet, that is, upon application of tensioning movements, problems arise. When setting a tightened blind rivet relatively large forces, acting in the axial direction of the tensioning spindle, must be applied, so that a fixed clamping of the rivet spindle in an appropriate tool is necessary.
The same problems arise in a design of a self-drilling rivet disclosed in DE-A-2,548,860 where the rivet spindle has a quadratic cross-section. In this design as well, it is intended that a rotation-locked connection be established between the rivet spindle and the rivet casing, and thus here too, a special design of the open area cross section of the rivet casing will be needed.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a self-drilling blind rivet which would ensure a simple installation of the end region of the tensioning spindle thereof in a tool and, on the other hand, it will enable the transfer of the tensioning forces when setting an optimal clamping action on the tool.
According to the invention, the tensioning shank or spindle of the rivet has at least one protrusion, or similarly designed force application section at its end region having the rotational and tensioning force application element that emanates from the free end and passes across at least a portion of the length of the free projecting region over the rivet sleeve, said protrusion running over the cross section of the section of the tensioning shank and parallel to the axis of the tensioning shank. The section for force application is provided over at least a part of its surface with roughening, transverse ribs, undulations, knobs, or a knurled edge.
In this manner the rivet shank can be pushed into the tool with no problems, since no back-cutting is necessary as for the other known designs. Due to the protrusions or similar elements protruding radially over the cross-section of the shank, a sufficiently good rotational engagement of the tensioning shank with the tool will occur during the drilling process. Precisely due to the formation of at least one partial section of the section for the force application with toughening, transverse ribs, undulations, knobs or a knurled edge, no particularly large radial clamping forces are needed for the rivet shank in order to transfer the relatively large axial forces when setting the tension blind rivet. Therefore, a simple pressing of the corresponding tool parts onto the section of the tensioning shank for the force application suffices to achieve a sufficient friction force due to the surface configuration of the corresponding partial section or a partial force-closed connection when setting the rivet.
Due to the special design of the tensioning section of the shank it will suffice, for example, to provide clamping jaws that are held spring-loaded in a conical portion of the tool.
One particularly simple design is obtained when the section for force application has two diametrically opposing protrusions, or similar features, and its cross section is designed roughly at a right angle to the axis of the rivet. It is particularly advantageous that the section for force application has a width (measured transversely with respect to the axial direction) which is greater than the diameter of the rivet shank and a thickness (measured at a right angle to the axis) that is smaller than the diameter of the tensioning shank.
Therefore, during the drilling process, relatively large surfaces for force application will be provided for the rotation with two diametrically opposing protrusions or portions or similar features. Moreover, relatively large surfaces will be available that are equipped with roughening, transverse ribs, undulations, knobs, or a knurled edge, and are suitable for the transfer of tensile forces when setting the rivet. It is advantageous that the entire device has a consistent cross section throughout, and the end region of the tensioning shank is designed as a surface for force application, emanating practically from its free end, so that a simple insertion of the rivet spindle or shank into an appropriate tool will be always possible.
According to an embodiment of the present invention the width of the section for force application is at least 1.2 times the diameter of the tensioning shank. This will assure not only an excellent rotational lock for the transfer of the necessary torque when drilling, but also the advantage is achieved that the rivet sleeve does not need to be separately secured against lost even when it is only loosely placed onto the tensioning shank and slides axially along a partial region.
According to another embodiment, parallel to the protrusions, or similar elements on the section for force application, one or more grooves or channels are provided on the tensioning shank. Thus for the rotational lock, it is possible to adapt the shank to even special tools, where an excellent force application is possible for the tensioning motion due to a corresponding larger surface in conjunction with the roughening, transverse ribs, or similar features provided on the surface.
According to yet another embodiment, protrusions, or similar elements formed on the section for force application are formed by partial protrusions following each other in an axial direction. These protrusions, or similar elements thus form not only an optimal potential structure for force application in a rotational drive, but due to the recesses formed between the partial protrusions, they will also provide an excellent potential structure for force application during the tightening movement.
It is further advantageous if the section for force application is produced by pressing the end region of the tensioning shank after the preassembly of the rivet sleeve. Thus, the free end region of the section for force application can be deformed after the assembly of the rivet sleeve accordingly, so that the rivet sleeve itself can have a cylindrical drilled hole in the usual manner, and thus will be held easily sliding and rotating on the tensioning shank. Due to this holding of the rivet sleeve, it is also possible, without any problems, to produce a rivet sleeve with a painted or colored surface. Due to the excellent rotational lock in the region of the tensioning shank, there is no need to make use of the rivet sleeve for the transfer of torque. The rivet sleeve during the drilling process will not rotate since it is sitting loosely on the tensioning shank. In addition, the surface of the part being attached, and also the stop flange of the rivet sleeve itself will not be damaged by any means at the end of the drilling process. Paint applied to the rivet sleeve and to the part being attached thus will not peel off. Due to the loose holding of the rivet sleeve it is also possible to provide the stop flange with any kind of head shape.
Due to the subsequent deformation of the end region of the tensioning shank, an optimum proof against loosing the attached parts will be provided for the rivet sleeve, so that in addition, the optimum cross-sectional shape of the section for force application can be produced.
Additional advantages of the present invention will be explained in greater detail below with reference to the drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a self-drilling blind rivet of the invention; and
FIG. 2 is a side view of the tension blind rivet of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The blind rivet consists essentially of a rivet casing or sleeve (1) and of a tensioning spindle or shank (2) that has on its one end a drilling unit (3) and on its other end region a force application section (4). At the transition between the tensioning shank (2) and the drilling unit (3), there is an expansion portion (5) that will cause an expansion of the free end of the rivet sleeve (1) when setting the blind rivet into the bore. A stop flange (6) is provided in the usual manner on the rivet sleeve (1).
In the region of the force application section (4) there is at least one protrusion or portion (9), or similar element that protrudes radially over the cross section of the section (2a) of the tensioning shank (2) located in the rivet sleeve (1); this protrusion or other element runs parallel to the axis of the tensioning shank (2).
Section for force application (4) of the tensioning shank (2) has at least one flattening (7). This flattening emanates from its free end and runs across the major part of the length of the free region extending over the rivet sleeve (1). This flattened part of shank (2) is used together with the protrusions (9) for the rotational lock of the tensioning shank (2) during the drilling process. Preferably, the section for force application (4) has an approximately rectangular cross section so that at least two diametrically opposing elongated projections (9), and also two flattenings (7) are formed.
The section (4) for force application of the tensioning shank (2) is provided on at least one partial segment thereof with toughenings, transverse ribs (8), undulations, knobs, or a knurled edge. The transverse ribs (8) or similar features form a special configuration of the tensioning shank (2) in order to better transfer the axial forces when setting the rivet by the tool, without making the clamping jaws of the tool grasping the tensioning shank (2) apply an excessively large force radially against the tensioning shank. One favorable effect, of course, will also be obtained when the corresponding clamping jaws of the tool have a surface corresponding to the roughenings, transverse ribs, undulations, knobs, or knurled edges.
With regard to the shown example it is further provided that the section (4) for force application has a width B, measured transversely to the axial direction, which is greater than the diameter (D) of the tensioning shank (2), and furthermore, a thickness (A) measured at a right angle to that width is smaller khan the diameter (D) of the tensioning shank (2).
In the illustrated embodiment, it is also evident that the width (B) of the section for force application (4) measured parallel to the flattenings (7) is at least 1.2 times the diameter (D) of the tensioning spindle (2). Thus a relatively broad flattening (7) will be possible for the rotational lock during the drilling process. Moreover, even when the transverse ribs (8) are provided along the broad flattenings (7), an optimum force transfer will be possible when setting the rivet.
The production of the section for force application (4) takes place in a very simple manner by flat pressing of the one end region of the tensioning shank (2) after the mounting of the rivet sleeve (1). Thus, after the final assembly of the blind rivet, only the section for force application will have to be shaped by deformation of the tensioning shank (2). During this shaping process, the roughenings, transverse ribs (8), undulations, knobs, or a knurled edge can be produced.
In the illustrated example, the transverse ribs (8) or similar features are provided on the flattenings (7), or at least on one of the two flattenings (7). It would also be possible to use the region of flattenings (7) solely for the transfer of the torque during the drilling process, so that the transverse ribs (8) or similar features could also be provided on one or both protrusions (9) of the section for force application (4). It is also possible to provide only one flattening (7), where the transverse ribs (8) or similar features could be provided to correspond with the cylindrical part lying opposite the flattening (7).
The term "flattening" is intended to mean not only a precisely planar surface; it would also be possible to design the flattenings (7) as slightly cambered so that the section (4) for force application could have a roughly elliptical cross-section, for example. It is also not absolutely required that the cross-section of the section (4) for force application be roughly rectangular. It would be quite possible to design the section (4) for force application having a three- or five-cornered configuration, for example, so that possibly also more than two protrusions (9), or similar features or flattenings (7) would be distributed across the perimeter of the section (4) for force application. Thus it is also possible to provide an asymmetrical cross-section for the section for force application, so that in regular or irregular sequence, bars, protrusions, or similar features, and also channels or grooves can be formed.
The transverse ribs (8) or similar parts can also be provided completely around the perimeter in the region of the section for force application (4).
As already mentioned, one or more channels or grooves can be provided on the tensioning shank (2) parallel to each protrusion (9) or similar feature, or parallel to several protrusions (9), respectively, or similar features at the section (4) for force application.
The protrusions (9), or similar features formed on the section (4), for force application need not cover its entire length, but can also be formed as partial bars or partial protrusions following in sequence in the axial direction.
As has been mentioned in the description, bars, protrusions, or similar features are produced by deformation or by pressing one end region of the tensioning shank. It would also be possible to bend the free end region of the tensioning shank around, for example, by 180°, so that this end region will again extend parallel to the tensioning shank in the opposite direction. This turned end will then form the bar protruding over the cross section of the tensioning shank, so that even then an excellent rotational lock and a large surface for force application will be created during the tensioning motion. In this regard it is also possible to design the end region of the tensioning shank in the shape of a curved eyelet, so that the two diametrically opposing curvatures of such eyelet will run parallel to the axis and form bars or protrusions extending across the cross section of the tensioning spindle.
The drilling unit (3) in the form of a drilling plate (10) is provided in the rivet. The inventive design described herein is not limited to blind rivets with this kind of the drilling unit (3). The drilling unit (3) can be designed in any other manner, where it can be manufactured as a single piece with the tensioning shank (2), or attached by a weld joint, and e.g., designed as a roughly cylindrical drilling part.
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A self-drilling blind tension rivet has a sleeve with a stop flange and a rivet shank and having at one end a drilling unit and at the other end a flattened section for engagement with a rotation and tension applying tool for drilling in and setting the blind tension rivet. The flattened section which extends over the major part of the length of the shank has roughened surfaces formed by transverse ribs and is limited by two elongated portions protruding radially beyond the outer diameter of a cylindrical part of the shank.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to dart games and in particular to a computerized dart game which has more than one microcomputer and which has a novel dart board.
2. Description of the Prior Art
Electronic dart games are known such as illustrated in U.S. Pat. Nos. 4,057,251, 1,199,564, 2,808,266, 2,818,259, and 3,309,091 in which patents impinge upon a board so as to cause segments of the board to close a switch and wherein such switches are connected to components for registering, totalling and displaying the score of the player.
SUMMARY OF THE INVENTION
The present invention comprises a computerized dart game which has a novel dart board formed with segments that are guided by guide ribs so as to actuate a matrix switch and wherein at least two microcomputers are utilized with one of the microcomputers scanning the matrix switch of the dart board to detect scoring and the other microcomputer controlling various indicator, totallizing and other functions of the game. The use of at least two microcomputers allows the operation of the game to be very rapid and allows many different functions to be provided for the game.
Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the dart game of the invention;
FIG. 2 illustrates the indicator and control board of the invention;
FIG. 3 is a plan view of the dart board of the invention;
FIG. 4 is a sectional view illustrating the details of the dart board;
FIG. 5 is a cut-away sectional view illustrating the dart board segments;
FIG. 6 is another cut-away view of the dart board;
FIG. 7 illustrates the positioning of the switch elements;
FIG. 8 is a sectional view of the dart board;
FIG. 9 illustrates the matrix switch of the invention;
FIGS. 10A and 10B comprise a schematic view of the microcomputer boards;
FIGS. 11A, 11B and 11C comprise electrical schematic of the detecting and control boards; and
FIG. 12 comprises electrical schematic of the audio board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the dart game 10 of the invention which has a base 11 and a top extending portion 12 which carries the dart board 13. A control panel 14 is illustrated in FIG. 2 in greater detail and comprises a game selector switch 36 which allows for example the selection of five different games with three levels of skill such as high score which can be selectived by depressing a switch 39, 501 which can be selected by depressing a switch 38, 301 which can be selected by depressing a switch 37, shanghai which can be selected by depressing a switch 43, and scram which can be selected by depressing a switch 42. A double in switch segment 40 allows double in to be selected and a double out switch segment 41 can also be selected. It is to be realized, of course, that both double in and double out can be selected upon payment of the appropriate fee by each player. Coin slots 21 are mounted on the side of the game 10 and a coin ejector and return 22 is also mounted on the game 10.
The control board 14 also carries indicator such as remove dart indicator 31, a bust indicator 32, a throw dart indicator 33, a game over indicator 34, a push button 44 and scoring indication 23 which has first, second, third and fourth player indicators 24, 25, 26 and 27, a temporary score 28 and a dart round indicator 29.
FIGS. 3 through 8 illustrate in detail the dart board 13 of the game. The target 13 comprises a plurality of radial ribs 81 through 100 which are spaced equal angularly relative to each other and which are joined at their outer ends by a rim 73 which has its inner edge tapered so as to throw darts into the target. Radial dividers 200, 201, 202 and 203 are also provided in the target and target segments comprise the inner bullseye 204, a plurality of first inner pie-shaped elements 205a through t are located in the spaces between the ribs 81 through 100 and the ring 202 and 203. Smaller double score elements 206a through 206t are mounted between rings 201 and 202. Target segments 207a through 207t are mounted between rings 200 and 201. Smaller triple score segments 208, 208a through 208t are mounted between rings 73 and 200.
As shown in FIG. 8, the target assembly 13 is attached to the front panel 71 of the upper part 12 of the case by a screw 77 and a rim 76. A matrix switch structure 211 is mounted to the upper portion 12 by bolt 212 which is connected to the portion 71 as shown in FIG. 8. Each of the target segments 203 through 208 are formed with feet 213 as is illustrated in FIG. 8 which are mounted so as to engage the pressure switch 211a which is mounted on the pressure switch support 211 as illustrated in FIG. 8. As illustrated in FIG. 7, the matrix switch 211 has openings so that the feet 213 can close the switch at locations associated with the feet 213 of the target segments so as to indicate when a dart 214 impinges on a switch segment as illustrated in FIG. 4. Each of the switch segments is formed with a plurality of openings 216 into which the point of the dart 214 can enter and the reaction of the segments such as segment 205d when hit by the dart is to cause its associated switch actuated feet 213 to engage a rubber pad 217 which overlies the matrix switch 211a and the feet 213 of the target segment 205d will close the switches associated with the target segment 205d when the target segment is hit with a dart 214.
As shown in FIGS. 5 and 6, guide ribs 220 are mounted on the ribs 81 through 100 so as to engage and guide the target segments 203 through 208 of the target board.
FIGS. 10A and 10B illustrate the leads 101 to 120 which are connected to the dart board switch matrix 211a and these leads are connected to a microcomputer 66 which may be an Intel type 8748 which scans the dart board matrix switch to detect when darts strike the target board. The Intel type 8748 includes a clock, an eight bit CPU, a 1024 word program memory, a 64 word data memory, an eight bit timer event counter and 27 input/output lines.
Certain of the leads 101 through 120 are connected to the microcomputer 66 through the unit 67 which may be a type 74LS156. A second microcomputer 45 may be of the type 8031 available from Intel which receives an input from an oscillator on terminal 10 from the crystal CR. The microcomputer 45 can be reset by the reset switch 57 which is connected to terminal 9. Leads 32 through 39 are connected from the microcomputer 45 to a buffer 62 which may be a type 74LS273 and to a unit 63 which may be a type 2716 and to a unit 64 which may be a type 2716. The leads 32 through 39 are also connected to a unit 46 which may be a type 74LS244. The microcomputers 45 and 66 are connected together by leads 401 through 403 as shown.
As shown by FIGS. 11A, 11B and 11C, the matrix switch 211 supplies inputs through the transistors Q25, Q26, Q27 and Q28 to displays 501 through 517. Unit 518 is connected to unit 519 and the unit 518 might be a type 74LS244 and the unit 519 may be a latch buffer type 74LS2737 which is connected through suitable driver amplifiers to the displays 501 through 504. The unit 521 is also connected to the unit 518 and might be a type of 74LS273 and drives the displays 506 through 509 through the driver amplifiers illustrated.
The unit 518 is also connected to the unit 522 which might be a type 74LS273 which is connected to the display units 510 through 513. The unit 518 is also connected to unit 523 which might be a type 74LS273 which is connected through suitable drivers to the displays 514 through 517. A unit 524 is connected to unit 518 and might be a type 74LS273 and is connected through suitable drivers to transistors Q1 through Q8 which drive lights 525 through 532 which might be respectively light up the indications which show the temporary score, the throw darts, player number 1, player number 3, player number 4, player number 2, game over, and Push.
A unit 533 is connected to unit 518 and might be a type 74LS273 and is connected through suitable drivers to transistors Q9, Q10, Q14, Q15 and Q16, to drive lamps 534 through 538. Lamp 534 might be "Darts". Lamp 535 might indicate bust, lamp 536 might indicate rounds, and light 538 might indicate remove darts.
The unit 540 which might be a type 74LS173 is connected to unit 518 and is connected through suitable drivers to transistors Q17 through Q24 which drive lights 541 through 548 which might respectively indicate 25 cents, Scram, count-up, 501, 301, shanghai, double-in, and double-out.
The programs for the microcomputers 45 and 66 are attached.
FIG. 12 illustrates the audio board and comprises speech in terminals audio out terminals, speaker out terminal and power in terminals and tone-in terminal which are respectively connected to amplifiers 561, 562 and 563. A unit 560 might be a type 7815 is connected as shown and the audio board.
It is to be realized that in use the players deposit coins in the slot 21 and presses the selected switch 36 to choose the game they wish to play. Then the players alternately throw their darts at the target board 13 and the scores are recorded on the scoring indicia 23. As each dart is thrown, if it hits any of the target segments the associated switches in the switch matrix 211a will be closed which will be fed to the scanning microcomputer 66 which will then be supplied through the microcomputer 45 to the displays 501 through 517 to indicate the scores of the players.
This continues until the game has ended at which time the game over light 34 will be illuminated and the winner will be indicated.
If points of the darts break off in the target, the matrix 211 can be by taking the nuts 212a off of bolts 212 and then the broken points can be pushed through the target.
The software for the microcomputers is such that if a dart is thrown which hits another dart in the board and then is deflected to a second segment only the score in the second segment will result.
The audio board produces an audible sound when a segment is struck.
Although the invention has been described with respect to preferred embodiments, it is not to be so limited as changes and modifications will be made which are within the full intended scope as defined by the appended claims.
PROGRAM FOR MICROPROCESSORS 45 AND 66 ##SPC1## ##SPC2## ##SPC3## ##SPC4## ##SPC5## ##SPC6## ##SPC7## ##SPC8##
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A novel dart game which allows one or more players to participate and which has a dart board mounted over a matrix switch and with segments to actuate the matrix switch when struck by a dart thrown by a player and which uses a first microcomputer to scan the matrix switch to detect where the dart struck the dart board and a second microcomputer which performs numerous functions such as totalizing the score for each player, actuating indicators which inform the players of the conditions and score of the game for each player. The novel dart board is formed with movable segments which are guided by guide ribs so as to provide smooth and accurate response of the segments to darts received on the board.
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BACKGROUND OF THE INVENTION
The present invention relates to a ride-on toy stylized as a friendly character. Such toys are also often styled in a saddle-type configuration including a saddle-type seat. The toy is typically connected to the supporting surface by a connector. The connector can include a motorized member that moves the seat automatically or a biasing member that manually reacts to the movement of the child. Whether the toy and connector are motorized or self-powered, children get excited about and spend endless hours enjoying such ride-on toys. Generally, the connector supports the seat, allowing the seat to move in various directions. Specifically, in addition to an up and down (vertical) riding (bouncing) motion, some connectors of ride-on toys enable rotation or spinning of the seat while the child is sitting on the seat. Although rotation of the seat is desirable after the child has been seated on the toy, the climbing onto or off of a rotating toy may be somewhat difficult.
Parents generally encourage children to play independently as early as possible. For a small child, however, the rotation and bouncing of the seat on a conventional ride-on device can make an unsupervised mounting of such toys an unstable and even potentially dangerous undertaking. There is therefore a need to develop a ride-on toy which allows relative rotation between the seat and connector, but which prevents rotation of the seat when the child is mounting the toy and then again allows rotation of the seat after the child has safely mounted the toy. In this way, the child can safely mount the toy and then safely enjoy the freedom of seat rotation and bouncing.
SUMMARY OF THE INVENTION
Generally, the present specification discloses a children's ride-on activity toy device. The ride-on toy device includes a seat, a connector and a base. The seat is stylized as a friendly character and includes a saddle/seating area (e.g., a saddle formed on the character's back). The connector supports the seat above a base, the base contacting and stabilizing the device on a supporting surface in a manner that allows multiple degrees of freedom between the seat and the connector.
Specifically, the present invention seat is stylized as an animal character (e.g., a horse, zebra, camel etc.). The back of the animal character may include a seating area stylized a saddle. A connector, in accordance with the present invention, may support the seat above a base (and thus also above the supporting surface) and may include a first connector portion and a second connector portion. The first connector portion being connected to the seat and the second connector portion being connected to the base.
A connector in accordance with the present invention may be connected to the seat at a connection portion located on the bottom of the seat. The connector may be in the form of a compressible column and includes an upper column portion or first connector portion that moves telescopically relative to a lower column portion or second connector portion. The upper end of the first connector portion may be connected to the seat and the lower end of the second connector portion may be connected to the base. When a child sits on the seating area of the seat, the force of the child's weight is transmitted through the first connector portion to a biasing member to compress the biasing member and force the first connector portion toward the second connector portion, thus reducing the overall length of the connector. Furthermore, a child who sits on the seat with their legs touching the ground can adjust the force applied to the biasing member to initiate a bouncing (up and down in the vertical direction) movement with the seat.
In order to provide a safe play experience, the present invention includes a safety mechanism that prevents the seat from rotating relative to the base when insufficient force is applied to the biasing member, but allows the seat portion to rotate relative to the base when sufficient compressive force (e.g, the weight of the child) is applied to the seat (and thus, the biasing member). The safety mechanism includes a first series of projections associated with the connector's first connector portion and a second series of projections that are associated with the connector's second connector portion.
When insufficient compressive force is applied to the biasing member, the biasing member forces the first series of projections toward the second series of projections such that the first and second series of projections are in rotational alignment (i.e., they are interlocked). When the first and second series of projections are in rotational alignment, rotation of the seat, and thus, rotation of the first connector portion, causes the first series projections to engage with the second series of projections to prevent rotation of the seat about a vertical axis. However, when sufficient compressive force (e.g., weight of a child) is applied to the seat and thus to the biasing member, the first series of projections separates from the second series of projections (the first and second series of projections are moved out of rotational alignment). As a result, when a relative rotational force is applied between the seat and the base, the first series of projections rotates freely about a vertical axis relative the second series of projections. In other words, when the seat along with the first connector portion is sufficiently compressed relative the second connector portion, the seat is allowed to rotate freely about a vertical axis relative to the second connector portion and the base.
In use, when a child attempts to mount the seat, because the seat is yet unloaded, the biasing member engages the safety mechanism to prevent the seat portion from rotating about a vertical axis relative to the base. However, when the child has mounted the seat, the weight of the child compresses the biasing member to disengage the safety mechanism allowing the seat portion to rotate about a vertical axis relative to the base (as well as bounce up and down on the vertical axis).
Along with a seat, the ride-on toy of the present invention may also include a hand grip for stability. A hand grip also helps to allow a child to transfer motion energy to this self-energized toy. In addition, the ride-on toy of the present invention may include an electronic entertainment device with sensors that are added to detect operation (motion energy) of the ride-on toy and trigger sensory stimulating output (e.g., lights, sounds etc.) to increase the entertainment experience of the child.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a perspective view of the ride-on activity device in accordance with the present invention.
FIG. 1B illustrates a perspective view of the ride-on activity device of the FIG. 1A showing how an electronic entertainment device interconnects with the ride-on activity device.
FIG. 1C illustrates an electronic schematic of the electronic entertainment device of FIG. 1B .
FIG. 2 illustrates a child (in phantom lines) seated on the ride-on activity device of FIG. 1A with their feet on the base and clutching the handle members of the electronic entertainment device.
FIG. 3 illustrates an exploded view of the ride-on activity device of the FIG. 1A showing the seat, the connector, and the base.
FIG. 4 illustrates an enlarged perspective view of a connector in accordance with the present invention showing the first (upper) connector portion assembled onto the second (lower) connector portion.
FIG. 5 illustrates an enlarged perspective view of the unloaded connector of FIG. 4 (with the cover member of the first connector portion removed to expose the internal workings of the connector).
FIG. 6 illustrates an enlarged perspective view of the connector of FIG. 5 with the biasing member and the first connector portion in the loaded position.
FIG. 7 illustrates a close-up side view of the connector of FIG. 5 with the side walls of the cover member and flange of the first connector portion removed to expose the connector's rotational safety feature.
FIG. 8 illustrates a close-up perspective view of the loaded connector of FIG. 6 with the side walls of the cover member and flange of the first connector portion removed to expose the connector's rotational safety feature.
FIG. 9 illustrates a child sitting on a ride-on device in accordance with the present invention moving the device in directions indicated by the directional arrows.
Like reference numerals have been used to identify like elements throughout this disclosure.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, a ride-on activity device 100 is disclosed. FIG. 1A illustrates a perspective view of the ride-on activity device 100 in accordance with the present invention. The device 100 includes a base 120 for stabilizing the ride-on activity toy on a supporting surface (floor) 101 , a seat 102 on which a child sits and a connector 110 for connecting and movably supporting the seat above the supporting surface 101 . A child sitting on the seating area 105 of the seat 102 with their feet on the base 120 can bounce up and down (along a vertical axis) relative to supporting surface 101 and spin (about the vertical axis) relative to supporting surface 101 .
The seat 102 is stylized as a friendly character or other attractive object. Specifically, as illustrated, the toy 100 can be stylized as animal and the seating area 105 can be stylized as a saddle. The base 120 serves as a stabilizer for the device 100 on the supporting surface 101 . Thus, the base 120 functions to prevent the device 100 from tipping over. The base 120 also serves as a foot rest for a child using the device 100 . The base 120 could be eliminated if the connector 100 is otherwise secured to the supporting surface 101 .
FIG. 1B illustrates a perspective view of the ride-on activity device 100 of the FIG. 1A showing how an electronic entertainment device 130 interconnects with the ride-on activity device 100 . The electronic entertainment device 130 connects to the head portion of the animal character and includes a handle portion 132 , 134 and an electronics unit 131 . The handle portion includes two handle members 132 , 134 that connect to the head of the animal character. The handle members 132 , 134 provide handles with which a child can stabilize themselves while the child is bouncing and spinning on the seating area 105 . In mounting the electronic entertainment member 130 to the device 100 , each handle member 132 , 134 includes an end connector 140 A, 140 B which are respectively received in openings 145 A and 145 B ( 145 B not visible in FIG. 1B ) in the head of the animal character. A further support connection is made between the electronic entertainment device 130 and the device 100 as the post 150 of the electronic entertainment device 130 is received in the receptacle 155 in the head of the animal character. The handle members 132 , 134 also support the electronics unit 131 therebetween.
FIG. 1C illustrates an electronic schematic of the electronics unit 131 of the electronic entertainment device 130 of FIG. 1B . The general operation of the electronics unit 131 is managed by a microprocessor/controller 175 powered when ON/OFF switch 165 is turned to the ON position. The electronics unit 131 further includes a conventional motion switch 170 for triggering sensory output (e.g., sounds, lights, vibration etc.). Other types of switches may be employed that receive external input (e.g., sound, motion, pressed button etc.) signals from the inputs and transmit those signals to the controller 175 for processing. Upon receipt of activation signals from the various inputs, the controller 175 then triggers a number of colorful LEDs 160 and a speaker 180 to generate sensory output (including music and/or sound effects).
Furthermore, the electronic entertainment device 130 includes attractive entertainment characters that are mechanically connected to the electronic electronics unit 131 by resilient members 137 A, 137 B (e.g., springs etc.). In addition, the electronics unit 131 includes a mechanical roller 139 containing a switch for triggering electronic sensory stimulation (e.g., sounds and lights) to encourage a child to spin the roller 139 .
FIG. 2 illustrates a child 200 (in phantom lines) seated on the ride-on activity device 100 of FIG. 1A with their feet on the base 120 and clutching the handle members 132 , 134 of the electronic entertainment device 130 . In this position, the child 200 can bend their knees to bounce up and down (along a vertical axis) on the device 100 . The connector 110 enables the seat 102 to bounce relative to the base 120 as further described below.
FIG. 3 illustrates an exploded view of the ride-on activity device 100 of FIG. 1A showing the seat 102 , the connector 110 , and the base 120 . Specifically, FIG. 3 shows how the connector 110 is positioned between the base 120 and the seat 102 . A portion of the connector 110 fits into an opening 305 in the base 120 and is secured to the base 120 . The pivotal connection between the connector 110 and the seat 102 will be described below.
FIG. 4 illustrates an enlarged perspective view of a connector 110 in accordance with the present invention showing the first (upper) connector portion (generally designated as 420 ) assembled onto the second (lower) connector portion (generally designated as 430 ). First connector portion 420 is separable into a cover member 420 A and a lower ring 420 B. Cover member 420 A and lower ring 420 B are connectable by snapping cover member 420 A onto lower ring 420 B. Cover member 420 A includes projection 420 H, disposed on guide member 420 C. Lower ring 420 B includes a catch member 420 G having an opening for receiving projection 420 H when catch member 420 G is slid onto projection 420 H. Lower ring 420 B also includes a receiver 420 D that is engaged by guide member 420 C to ensure alignment between catch member 420 G and projection 420 H. Also, as the cover member 420 A is snapped onto lower ring 420 B, flange 4201 receives the lower edge (not shown) of the cover member 420 A. Furthermore, FIG. 4 shows reinforcement ribs 420 N and a bias guide 440 extending from an opening in cover member 420 A and also shows securing members 420 E, 420 F for securing the first connector portion 420 to the underside of the seat 102 .
As mentioned above, the connector 110 securely supports the seat 102 above the base 120 while allowing the seat 102 the freedom to bounce up and down (along a vertical axis) and to rotate relative to the base 120 (about a vertical axis). To this end, the first connector portion 420 , moves telescopically up and down relative to second connector portion 430 . In other words, as cover member 420 A is compressed downward relative to column post 430 B, cover member 420 A, guide ring 420 J, and the lower ring 420 B slide downward relative to column post 430 B. The relative telescopic movement between the first connector portion 420 and the second connector portion 430 is more clearly illustrated in the figures below. Furthermore, the rotational relationship between the first connector portion 420 and the second connector portion 430 will be discussed below in conjunction with the rotation safety feature of the device 100 .
FIG. 5 illustrates an enlarged perspective view of the unloaded connector 110 of FIG. 4 with the cover member 420 A of the first connector portion 420 removed to expose the internal workings of the connector 110 . The cover member 420 A is removed to reveal interior portions of the connector 110 including the biasing member 530 that provides the resilience for the vertical bouncing feature of the device 100 . FIG. 5 also shows an upper stop 430 A of the column post 430 B that limits the relative compression between the first connector portion 420 and the second connector portion 430 by limiting the overall downward travel of the cover member 420 A. Biasing member opening 550 is disposed in the upper stop 430 A for receiving the biasing member 530 . The biasing member 530 rests on a biasing surface (not shown) that is fixed relative to the second connector portion 430 . When loaded, the biasing member 530 is compressed between the biasing surface (not shown) and the biasing guide 540 . In other words, when the cover member 420 A pushes the bias guide 540 downward, bias guide 540 in turn compresses the biasing member 530 against the biasing surface (not shown). When the compressive force is released, the biasing member 530 exerts a reactive force back against the cover member 420 A to urge the seat 102 back upward. Therefore, the up and down bouncing motion is accomplished by cyclically loading the biasing member 530 and releasing the load as the child bounces up and down on the seat 102 .
As discussed above, in addition to the up and down bouncing motion, the connection between the connector 110 and the seat 102 allows the seat 102 to rotate about a vertical axis relative to the base 120 . However, this rotational connection mechanism of the present invention includes a safety feature that prevents rotation in certain situations when rotation might be inconvenient or unsafe for a child. More specifically, the connector 110 includes a safety mechanism that enables a child to mount and dismount the seat 102 without fear that the rotating seat 102 will cause a potential instability.
FIG. 6 illustrates an enlarged perspective view of the loaded connector 110 of FIG. 5 with the biasing member 530 and the first connector portion 420 in the loaded position. In FIG. 6 , the bias guide 540 is shown in a lower, more compressed state, than that shown in FIG. 5 to illustrate its configuration under compression by a force F (caused by a child sitting on the seat 102 ). Correspondingly, the lower ring 420 B is shown in a lowered compressed state relative to that shown in FIG. 5 . In the compressed configuration of FIG. 6 , the inner ring surface 420 K of the lower ring 420 B and the lower stop 430 D can be seen. When the lower ring 420 B is shown in the compressed configuration illustrated in FIG. 6 , the ring projections 420 L disposed on the inner ring surface 420 K of the lower ring 420 B are visible and the stop projections 430 M disposed on underside surface the lower stop 430 D are also visible.
The rotation safety feature of the device 100 in accordance with the present invention will now be discussed. In a non-compressed state (as illustrated in FIG. 5 ), lower stop 430 D of the second connector portion 430 and ring surface 420 K of the first connector portion 420 remain close to each other such that stop projections 430 M engage with ring projections 420 L to prevent relative rotation between lower ring 420 B and lower stop 430 D. In other words, when an insufficient compressive force F (insufficient to compress the biasing member 530 ) is applied to the connector 110 , ring projections 420 L rotatably engage stop projections 430 M to prevent the first connector portion 420 from rotating relative to the second connector portion 430 . On the other hand, when the seat 102 is sufficiently loaded (sufficient to compress the biasing member 530 ), it in turn sufficiently loads the first connector portion 420 to cause clearance between ring projections 420 L and stop projections 430 M. Therefore, when sufficient compressive force is present such as illustrated in FIG. 6 , lower ring 420 B, cover member 420 A, and thus the seat 102 is freely rotatable relative to second connector portion 430 .
FIG. 7 illustrates an enlarged cut away view of the connector 110 in an unloaded state as also illustrated in FIG. 5 . In the FIG. 7 illustration, flange 4201 is partially removed to more clearly show ring projections 420 L and stop projections 430 M in a rotational alignment which prevents rotation of the first connector portion 420 relative to the second connector portion 430 .
FIG. 8 illustrates an enlarged perspective view of the connector 110 of the invention in a compressed configuration (as also illustrated in FIG. 6 ) that separates the ring projections 420 L and the stop projections 430 M out of rotational alignment with each other. Again, the separation of ring projections 420 L and stop projections 420 M enable relative rotation between first connector portion 420 and second connector portion 430 .
FIG. 9 illustrates a ride-on activity device 100 of FIG. 1A in accordance with an embodiment of the present invention showing arrows indicating the direction of a child bouncing and rotating on the device 100 . In use, a child 200 approaches the ride-on activity device 100 and attempts to mount the device 100 . During mounting, the child 200 benefits from being able to support himself/herself against the seat 102 that does not rotate when urged (e.g., when swinging a leg around the back of the seat 102 ). The device 100 allows the child 200 to mount the seat 102 with maximum support by preventing rotation during mounting. After, the child 200 has mounted the seat 102 , the weight of the child will load the bias member 530 and allow the child 200 to bounce up and down on the seat as indicated in FIG. 9 by arrows 910 A, 910 B. In addition, the bias member 530 is chosen such that the weight of the child 200 sufficiently loads the seat 102 and thus the first connector portion 420 to force the connector 110 to the compressed configuration as discussed above (with respect to FIGS. 6 and 8 ). In this compressed configuration, the safety rotation mechanism disengages (causing ring projections 420 L to be separated from stop projections 430 M) to allow the seat 102 to freely rotate as indicated in FIG. 9 by arrow 920 . The child 200 will then be able to freely bounce and rotate. When the child 200 is ready to dismount, the child 200 rises from the seat 102 to unload the connector 110 . Unloading the device 100 causes the rotation safety mechanism to again engage (causing ring projections 420 L to be in contact with stop projections 430 M) to prevent rotation so that the child 200 can support themselves as they dismount safely.
It will be appreciated that the embodiments described above and illustrated in drawings represent only a few of the many ways of implementing the present invention. For example, the relative movement between the seat 102 and the base 120 or supporting surface 101 is due to the connections between the seat 102 and connector's first connector portion 420 , between the connector's first connector portion 420 and the connector's second connector portion 430 , or the connector's second connector portion 430 and the base 120 . In other words, relative movement between the seat 102 and base 120 can be due to any of the foregoing connections. Specifically, the rotation between the seat 102 and the base 120 may be due to the connection between the second connector portion 430 and the base 120 rather than between the first connector portion 420 and the seat 102 .
The connection between the seat 102 and the connector 110 can be located anywhere on the seat 102 , but is shown on the bottom of the seat 102 in the drawings. The connection between the first connector portion 420 and the second connector portion 430 can be of any type, but is shown as a telescopic connection in the drawings. The connection between the second connector portion 430 and the base 120 can be any type of connection and can be similar to the connection between the first connector portion 420 and the seat 102 .
The connection between the seat 102 and first connector portion 420 may be in an upper portion of the seat 102 when the connector 110 is an overhead support (not shown in the drawings). Alternatively, the connection between the seat 102 and first connector portion 420 may be in a lower portion of the seat 102 when the connector 110 is a column-type support.
The electronics assembly 130 in accordance with the present invention may include any combination of sensors, switches, lights, speakers, animated members, motors, and sensory output generating devices. The microprocessor unit 175 may produce any combination of audio and visual effects including, but not limited to, animation, lights, and sound (music, speech, and sound effects). The output pattern is not limited to that which is discussed herein and includes any pattern of music, lights, and/or sound effects. The electronics assembly 130 may also include additional switches or sensors to provide additional sensory output activation without departing from the scope of the present invention.
Thus, it is intended that the present invention cover the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. For example, it is to be understood that terms such as “left”, “right” “top”, “bottom”, “front”, “rear”, “side”, “height”, “length”, “width”, “upper”, “lower”, “interior”, “exterior”, “inner”, “outer” and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration.
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A ride-on activity device is disclosed, wherein the device includes a seat, a base and a connector for movably connecting the seat relative to the base. The connection between the seat and the base allows multiple degrees of freedom such that the seat is capable of bouncing and rotating relative to the base. The connection between the seat and the connector includes a rotation safety mechanism that allows rotation at the connection when the seat is occupied by a user and prevents rotation at the connection when the seat is unoccupied. Furthermore, the connector includes a resilient member that allows the seat to bounce vertically relative to the base.
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BACKGROUND OF THE INVENTION
The objective of the invention relates to a method for the processing of tires and for the manufacture of products comprised of the tire material, to a device for cutting up tires as well as construction of interwoven mesh structures or bodies such as blocks, hollow bodies, mats or aligned units manufactured from the cut-up tires.
The invention is particularly applicable to the conversion of used tires, non-recyclable for traffic purposes, arising from motor cars, road haulage trucks and aircraft, into a new basic construction element which can be used for the manufacture of a wide scope of commercial products. Intermediates for the manufacture of new end-products are rings cut out of the tires.
Comminution of tires no longer permissible for use as such, by means of shredders for example, with subsequent use of the fragments as aggregate material, in cement production or as fillers in road construction substrates for example, is well known. Further application possibilities for discarded tires are incineration and thus the production of heat energy, chemical decomposition into raw products or deposition on dumping grounds.
SUMMARY OF THE INVENTION
Of disadvantage in the known application possibilities is that the said possibilities only permit recycling after loss of quality, raw material or characteristic properties. Centralization of the application can only proceed via transportation of the tires without reduction of their volume.
Patent No. DE 39 33 729 A1 describes a process for recycling discarded tires wherein the tires are cut up to form endless ribbons. The array of utilities of such endless ribbons is relatively limited.
In Patent No. DE 33 086 51 A1 a network of tire shaped bodies is described wherein the tires are not cut into narrower slices or are arranged in cut form into rings or strips.
The disadvantage of this solution is that additional fastening elements such as rivets, clasps or pins are necessary for the interconnection of rings produced from tires.
In patent No. DE 42 009 49 A1 a method and device for the dismemberment of discarded tires is described wherein a fixed rotationally driven tire is cut into slices by means of adjustably arranged cutters on the outside face, resulting in production of the running tread of the tire, two tire walls and two wheel rim beads.
The invention is thus based on the objective of creating a method and a device by means of which effective reprocessing of a wide variety of tires is possible and intermediates of new end products with high user quality can be manufactured in simple ways at attractive prices.
A further objective of the invention is to demonstrate a new range of applications and utilization of the end products.
The said objective is achieved according to the invention by the features defined in sections of claims 1, 9 and 18 in conjunction with the features generic to the independent claims in each case.
Appropriate embodiments of the invention are to be found in the subordinate claims.
A particular advantage of the invention is that the conversion of the tires into intermediate product rings is a fully environmentally friendly production method, in the process of which no waste accrues and no pollutants are discharged, and wherein the tires are dismembered by a sequence of cuts in such a way that the two side walls are separated from the running tread and the rings arising from the side walls and/or running tread are combined together to form new products. The rubber-cased metal ring ensuring firm seating of the tire on the wheel rim can also be recycled.
All tires which cannot be fully remolded, are not deformed and have not been cut open transverse to the tread can be used for the method in terms of the invention. The method enables conversion of tires wherever they accumulate.
A further advantage of the invention exists in the fact that the elasticity of the rings retains its proportional share of the strength associated with the tire, production of the rings being such that the tire is fixed to a holding facility and rotated by a drive roller which produces an internal swelling and is aligned with a shaft possessing at least one cutting blade which cuts through the running tread of the tire from the inside.
The surface area and volume of the mass to be transported is reduced to material volume or unit weight respectively by the ring form created. In its new form, i.e. as rings, the tire is transportable without occupying the former volume of a complete tire. The rings created can be compressed to any desired two and three dimensional form permitted by the ring created.
The rings in suitable form can be stacked and transported. If the rings are to be transported to permanently installed cutting facilities or another recycling facility, it is advantageous for the purpose of saving transport space to slit the tires parallel to the middle of the running tread in such a way that two U-shaped parts result which can be stacked inside each other.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained hereinafter as several exemplary embodiments, part of which at least is shown in the Figures.
FIG. 1 shows a stylized view of the steering of the cut in a tire represented as a half,
FIG. 2 shows the products of the cut steering as represented in FIG. 1,
FIGS. 2A to 2 C show variants of the cutting devices,
FIG. 3A shows the formation of a ring chain,
FIG. 3B shows the formation of a interwoven material
FIG. 3C shows the construction of a basic element (four-component element)
FIG. 3D shows the construction of a basic element (three-component element)
FIG. 3E shows the formation of a mesh from basic elements according to FIG. 3C,
FIG. 3F shows the formation of a mat from basic elements according to FIG. 3C,
FIG. 3G shows the formation of a three-dimensional body from basic elements according to FIG. 3C,
FIG. 3H shows the formation of a rounded body from basic elements according to FIG. 3C,
FIG. 3K shows a cutout of initially interwoven mat,
FIG. 3L shows a woven bag,
FIG. 3M shows a woven tubular hollow body with a bottom,
FIG. 3N shows a cutout of a second interwoven mat,
FIG. 3O shows a cutout of a third interwoven mat,
FIGS. 3P to 3 U show further variants of interweaving for construction elements such as aligned units, mats and three-dimensional bodies for example,
FIG. 4 The arrangement of bodies for the construction of dikes
FIG. 5 shows the arrangement of mats as river bank protection,
FIG. 6 shows the arrangement of mats on the bed of a body of water,
FIG. 7 shows the arrangement of hollow bodies filled with bulk material for the construction of artificial dams,
FIG. 8 shows the arrangement of hollow bodies filled with water for the construction of artificial dams,
FIG. 9 shows the lining of a dam with interwoven mats,
FIG. 10 shows the reinforcement of a bank with interwoven mats,
FIG. 11 shows the construction of fascines for bank protection,
FIG. 12 shows the offsetting of depressions on the bed of a body of water by covering with a mat,
FIG. 13 shows the offsetting of depressions on the bed of a body of water by filling out with mats,
FIG. 14 shows the covering of underwater reefs with mats,
FIG. 15 shows the demarcation of fishery areas constructed with mats,
FIG. 16 shows the arrangement of mats for the protection of coral banks,
FIG. 17 shows the arrangement of mats for protection in lock flooding basins,
FIG. 18 shows the arrangement of mats for protection against the breakthrough of ice sheets,
FIG. 19 shows the arrangement of mats in pools,
FIG. 20 shows the arrangement of mats in rivets,
FIG. 21 shows the arrangement of mats as breakwaters,
FIG. 22 shows the arrangement of interwoven bodies as breakwaters,
FIG. 23 shows the arrangement of interwoven bodies as absorbers of undercurrents,
FIG. 24 shows the arrangement of interwoven bodies for quay protection,
FIG. 25 shows the arrangement of interwoven bodies for the protection of structures/buildings,
FIG. 26 shows the arrangement of interwoven bodies or mats for the protection of bridge piers,
FIG. 27 shows the arrangement of interwoven bodies or mats for the protection of bridge piers and similar structures,
FIG. 28 shows the arrangement of interwoven bodies as protection against shifting ice,
FIG. 29 shows the deployment of mats or interwoven bodies as filters,
FIG. 30 shows the deployment of mats or interwoven bodies as protection against falls over the edge,
FIG. 31 shows the deployment of mats or interwoven bodies as protection of the outside hull of ships,
FIG. 32 shows the deployment of mats for earth stabilization,
FIG. 33 shows the deployment of mats for plant protection,
FIG. 34 shows the deployment of mats for the construction of reservoir dams,
FIG. 35 shows the deployment of mats or bodies as avalanche protection,
FIG. 36 shows the deployment of mats or bodies in the foundations of buildings,
FIG. 37 shows the deployment of mats for the construction of reservoir dams or bodies as road substrata,
FIG. 38 shows the deployment of mats for lining pipe or cable shafts,
FIG. 39 shows the deployment of mats or bodies as protective elements during explosions,
FIG. 40 shows the deployment of mats for the prevention of falling rocks,
FIG. 41 shows the deployment of mats or bodies for the construction of shelters in earthquake zones,
FIG. 42 shows the deployment of mats for the protection of bunkers,
FIG. 43 shows the deployment of mats in connection with protective barriers,
FIG. 44 shows the deployment of mats as traffic guidance and crash protection in road traffic,
FIG. 45 shows the deployment of mats for drainage purposes,
FIG. 46 shows the deployment of mats for fencing purposes,
FIG. 47 shows the deployment of mats as load distribution elements,
FIG. 48 shows the deployment of mats for tree protection,
FIG. 49 shows the deployment of mats for silage coverage,
FIG. 50 shows the deployment of mats for landfill demarcation,
FIG. 51 shows the deployment of mats for raised access routes,
FIG. 52 shows the deployment of fire mats for burnt aisle counteraction against fires,
FIG. 53 shows the deployment of mats for lightning protectors and vehicle shelters,
FIG. 54 shows the deployment of mats for laying out paddy fields,
FIG. 55 shows the deployment of mats for road marking,
FIG. 56 shows transportation possibilities for mats and/or bodies respectively,
FIG. 57 shows the deployment of mats for the construction of safety cages in space.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a tire is cut in such a way that a running tread ring 1 and two side wall rings 2 , are obtained. The running tread ring 1 and side wall rings 2 are shown in FIG. 2 .
The running tread ring 1 can be dismembered into narrower rings by further cuts, just as can the side wall rings 2 . FIGS. 2A to 2 C show variants of the cutting devices.
The tire 3 is fixed in a holding facility or guide 4 or unsupported and rotated by a transversally arranged drive roller 5 and is laterally guided. The cutting blade 8 swings inside against the swelling 7 induced by the drive roller and cuts the tire 3 into at least 2 annular parts. The cutting edges are arranged in such a way that the rubber is tensioned against them during the process of cutting. Deposition of the halves of the tire as shown in FIG. 2C occurs on both sides, on top of each other and held together by suitable means. By using multiple cutter systems, several cutters 8 are variably adjustable on the shaft 6 in terms of their distance apart. Several rings of the same or different widths can be prepared from the running tread 1 of the tire 3 by this means. Removal of the rings from the cutting system into the stacking unit is effected by grasping elements. Stabilization of the cutting process is achieved by clamping the wheel rim beading in a receptive device. Any mechanical procedures as well as computer aided positioning techniques can be used. Cutting up the tires using a cutter 8 from the outside is also possible.
Creation of interwoven mesh structures or three-dimensional bodies is performed by joining the rings up by hand or by means of handling manipulators or clamping/gripping elements. Combination of the rings by hand is performed by gripping a ring and pressing it together in such a way that equivalent sized loops are formed to the left and right. Passage of a folded further ring through the two loops or openings makes it possible to grasp the loops of the second ring. Opening of the starting ring is prevented by fixation with the result that a new ring can be passed through the newly created loops. The weaving process described can be supported by devices diverting the weave created away from the amenity such that a continuous production process proceeds with the weaving equipment.
Several embodiments of the interwoven mesh structures and bodies obtainable from weaving are shown in FIGS. 3A to 3 H. Mats which can be used for the reinforcement of dikes against the influence of swollen waters for example are very effectively produced interwoven patterns.
FIG. 3A shows the creation of a ring chain where the individual rings are knotted together. FIG. 3B shows the creation of an interwoven mesh. FIG. 3C represents the construction of a four-component basic element, FIG. 3D that of a three-component basic element. FIG. 3E shows the creation of a mesh structure out of basic elements of type 3 C. FIG. 3F shows the construction of a mat, FIG. 3G the construction of a rectangular three-dimensional body, and FIG. 3H that of rounded bodies. FIG. 3K represents a cutout of an interwoven mat. FIG. 3L shows a woven bag which can serve as a container for hardcore for example. FIG. 3M represents a tubular hollow body closed at one end by a rounded bottom. FIG. 3N shows a cutout of a second interwoven mat and FIG. 3O a cutout of a third interwoven mat. FIGS. 3P-3U show further weaving variants providing construction elements for roping, mats and three-dimensional bodies for example.
A variety of different applications for new products manufactured by interweaving a series of closed rings is described hereinafter. FIG. 4 shows the construction of dams exhibiting filled hollow bodies 13 or interwoven bodies 25 in their interior. Stabilization of the dam structure results from hollow bodies 13 , interwoven bodies 25 or the incorporation of mats 9 , with the effect that the dam can stand up to greater loads than if merely constructed of earth 15 .
FIG. 5 shows the incorporation of mats as bank protective measures, where two overlapping mats 9 are arranged in the present embodiment. The mats 9 are let into the bank 10 , redistributing the pressure generated by the water 11 over the mats 9 and protecting the bank 10 against alluvial deposition and undermining erosion. This protective measure can be applied both for canals and natural banks.
FIG. 6 shows the arrangement of mats 9 on the bed of a body of water 12 preventing the scouring away of sand for example and the generation of underwater potholes/channels in the bedding. FIG. 7 represents hollow bodies filled with bulk material such as sand which can be installed as artificial dams of any desired length, height and width in the water 11 . A further construction form of hollow bodies 13 is shown in FIG. 8 where the hollow bodies 13 are filled with water 11 . To avoid the water escaping through the interstices of the woven structure the hollow bodies are lined with a waterproof sheeting 14 .
FIG. 9 shows the lining of a dam with woven mats 9 where the dam lining is covered with earth 15 and the dam exhibits a counter-shaft 16 which is also lined by the mats 9 . FIG. 10 represents a simplified form of bank reinforcement consisting of woven mats 9 where the mats 9 are partially let into the earth both in the water and on the bank. FIG. 11 shows the construction of fascines for bank protection where the rings 1 act in conjunction with stakes 17 . FIGS. 12 and 13 show the offsetting of depressions on the bed of a body of water by covering with a mat. With regard to the embodiment exemplified in FIG. 12, the depression 18 is covered over with a mat 9 , whereas in the embodiment exemplified in FIG. 13 the depression is filled out with mats 9 . FIG. 14 represents the covering over of underwater reefs 19 with mats 9 . This measure serves to protect watercraft against collision.
FIG. 15 shows practical implementation of the demarcation of fishery areas where mats 9 provide the said demarcation of the bodies of water. Fish can be effectively reared within the confines of the body of water separated by the mats 9 . FIG. 16 shows the arrangement of mats 9 for the protection of coral banks.
FIG. 17 represents an exemplary application where the internal space of lock flooding basins is lined with mats 9 . The mat 9 may serve for the recovery and security of vessels such as sports boats for example. FIG. 18 represents the application of mats as protection against the breakthrough of ice sheets. The mats 9 are attached to buoys 22 anchored below the surface of the water. If the water freezes over with an ice sheet 23 , the protective system of mats 9 and buoys 22 is situated below the surface of the ice. If a person should break through the ice 23 , the said person will be protected against submersion and/or drowning by the mats 9 .
The arrangement of mats according to FIG. 19 serves the purpose of removing refuse from ponds, for example fire deartment reservoir-pools by means of raising the mats 9 . FIG. 20 represents the application of mats 9 in rivers 24 in which the mats are incorporated as linings on the bed of the river. The said lining prevents any erosion of the bedding and deposition of sediment.
FIGS. 21-23 show the arrangement of mats 9 or interwoven bodies 25 respectively as wave absorbers or breakwaters. The mats 9 or interwoven bodies 25 respectively are arranged entirely or partly underwater. FIG. 24 represents an exemplary embodiment in which the interwoven bodies are arranged for the protection of quay facilities. The interwoven bodies can act in conjunction with buoys 22 , be anchored on the bed 12 of the body of water or be permanently fixed in the bed 12 . FIG. 25 is a general representation of the protection of structures/buildings by interwoven bodies 25 . Mats 9 may also be used instead of the interwoven bodies 25 . Selected structures in the present embodiment are buildings which are to be protected from contact with an excavator, or water engineering facilities such as harbors or bridges. The special protection of bridge piers 28 is represented in FIG. 26 where the bridge pier 28 is encased by mats 9 in this case. A further exemplary embodiment for the protection of bridge piers 28 , arches and dams against damage is represented in FIG. 27 . The application is achieved either by mats 9 in conjunction with buoys, or by interwoven bodies 25 . The interwoven bodies 25 or mats 9 respectively are arranged in front of the bridge piers 28 . FIG. 28 shows the arrangement of interwoven bodies 25 in water for protection against ice shifting during breakup on rivers, lakes and the sea. The masses of ice are intercepted by interwoven bodies so that damage can be avoided. The use of mats 9 or interwoven bodies 25 as filters is represented in FIG. 29 . For example, the mats 9 can be drawn through the water 11 by a boat 31 in order to pick up waste matter in the net structure of the mats 9 . It is equally possible to introduce mats 9 into sewage treatment tanks 29 to pick up waste matter. A further possible application of the mats 9 consists in arranging the said mats in front of the entry into the collecting basins so that waste matter is filtered out. An arrangement of mats 9 or interwoven bodies 25 as active protection of persons or animals is represented in FIG. 30 . The mats 9 or interwoven bodies 25 prevent possible falls over the edge. The arrangement of mats 9 on the outside hull of a ship protects the outer hull from mechanical damage. The use of mats 9 for earth stabilization is represented in FIG. 32. A special field of application is the securing of slopes, where either a single mat 9 or several mats 9 arranged over one another can be deployed. FIG. 33 represents the use of mats 9 for plant protection. The earth surface is laid out with mats 9 and the plants/shoots located in the interstices of the woven structure. FIG. 34 shows the use of mats 9 for constructing dams and overflow basins for water arising from swollen rivers. The mat 9 is laid out in a trench and stabilizes the dike of the overflow basin. As an alternative to the construction of overflow basins the dams stabilized by means of the mats 9 can also be used to construct saline recovery basins. FIG. 35 shows the application of mats 9 or interwoven bodies 25 as avalanche protection. The mats 9 and/or interwoven bodies 25 are arranged on the slope 33 and serve to intercept avalanches. FIG. 36 shows the use of mats 9 or interwoven bodies in the foundations of buildings. It is possible to stabilize both strip foundations and full surface foundations by the use of mats 9 or interwoven bodies 25 . FIG. 37 represents the arrangement of mats 9 as road construction substrate. The mats 9 are arranged under the road 34 . Instead of roads 34 , pathways and open spaces, particularly playing fields, can also be stabilized by use of mats under the ground. FIG. 38 shows the application of mats 9 for lining pipe or cable shafts. The pipes 35 or cables 36 respectively are bedded into the mats 9 and covered by overlaps if required. The application of mats 9 or interwoven bodies 25 as protective elements during explosions is represented in FIG. 39 . Thus, the mats 9 can be deployed as bomb protection mats or arranged for use during the detonation of ammunition findings. It is also possible to deploy staggered arrangements of interwoven bodies 25 as protective elements during blasting operations. In order to limit the evacuation radius during defusing/removal of unexploded bombs or minimize the effect of shrapnel on detonation, the said bombs or other explosive ammunition findings can be covered by mats 9 or interwoven bodies 25 .
Prevention of falling rocks is served by the arrangement of mats 9 as represented in FIG. 40 . The use of mats 9 or interwoven bodies 25 for the construction of shelters, in earthquake zones for example, is represented in FIG. 41 . Dugout shelters or bunkers as shown in FIG. 42 can be constructed using mats 9 or interwoven bodies 25 . The external surfaces of bunkers 38 can be dammed by mats 9 . Dugout shelters in mountainous regions can be constructed as before using mats 9 and/or interwoven bodies 25 , which also offer protection against lightning. The aforementioned results from the Faraday cage effect of metallic components of the weave.
FIG. 43 shows the deployment of mats 9 in conjunction with protective barriers. The mats 9 are arranged in such a way that they form an interceptive possibility for vehicles coming off the road. Damage to the vehicles is minimized by the elasticity of the mats 9 . FIG. 44 shows the deployment of interwoven bodies 25 or mats 9 as traffic guidance elements and crash protection in road traffic. The said elements are primarily arranged parallel to the road 34 in the region of curves. FIG. 45 represents the use of mats for drainage purposes next to the road 34 . The mats are rolled up in the present embodiment and thus achieve the drainage function. In FIG. 46, the mats 9 are used as fences and serve to separate areas from humans and animals. Fences of this kind are also applicable against snowdrifts or accumulations of other material, in the proximity of landfills for example. FIG. 47 shows an application variant as load redistribution elements. Use of the mats 9 effects a redistribution of the loading and reduction of the pressure on the ground when freight is set down. The application of mats 9 as shown in FIG. 48 is suitable for the protection of trees. Thus on the one hand, the trunks of the trees can be protected by envelopment in mats 9 , and on the other hand, the root area by laying out mats 9 . The use of mats 9 for covering silage heaps is as shown in FIG. 49 . The contents of the silage heap is covered over with mats 9 , resulting in protective coverage on the one hand and weighting on the other hand. The deployment of mats 9 for landfill demarcation is represented in FIG. 50 . Mats 9 are arranged both underneath and above the body of the waste 43 , on the one hand covering the body of the waste 43 , and on the other hand delimiting the said waste 43 against the surrounding earth. The arrangement of mats 9 according to FIG. 51 is suitable for the construction of chronologically raised access routes. As the body of the landfill 43 increases in height mats are laid out in a staggered arrangement on top of one another. The use of mats 9 as burnt aisle fire mats is represented in FIG. 52 . The mats are laid out and set on fire in order to produce a counteracting fire. The spread of fire is thus effectively prevented during forest fires for example. The arrangement of mats 9 according to FIG. 54 serves the laying out of paddy fields for example. The use of mats in arid regions is represented in FIG. 55, where mats 9 are incorporated in the road or trail 34 . If the roadway is covered by sand drifts a metal detector reacting to the metal parts woven into the mat can be used to locate the original route 34 . Mats and interwoven bodies can be transported or put in place with the aid of carrier units such as gas-filled balloons, helicopters or airships. Transportation can be either in horizontal or vertical position, as can be seen in FIG. 56 . The use of mats 9 and interwoven bodies ( 25 ) in space is indicated in FIG. 57, where aerospace technology ( 45 ) can be set up in a safety cage constructed from mats 9 or interwoven bodies 25 .
The invention is not restricted to the exemplary embodiments represented here. On the contrary, it is possible to implement other embodiment variants by combination and modification of the means and features explained without abandoning the terms of reference of the invention.
List of reference codes
1 Running tread
2 Side rings
3 Tire
4 Guide
5 Drive roller
6 Shaft
7 Swelling
8 Cutting blade
9 Mat
10 Bank
11 Water
12 Bed of body of water
13 Hollow body
14 Waterproof sheeting
15 Earth
16 Counter shaft
17 Pole
18 Depression
19 Reef
20 Fish
21 Lock flooding basin
22 Buoy
23 Ice sheet
24 River
25 Interwoven body
26 Waves
27 Quay facilities
28 Bridge pier
29 Sewage treatment tank
30 Entry into tanks
31 Ship
32 Plants
33 Slope
34 Road
35 Pipe
36 Cable
37 Ground opening
38 Bunker
39 Crash barrier
40 Load
41 Tree
42 Silage heap
43 Body of landfill
44 Paddy fields
45 Aerospace technology
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A method for processing tires and providing a product made form the tire material, by cutting each tire by a sequence of cuts to form two side walls and several tire rings of the running tread, separating the two side walls from the tire rings of running tread, combining the tire rings together to form the product by looping a first tire rings directly to a second tire rings, the second tire rings is looped directly to the third tire rings until the n−1 tire rings is looped to the last tire rings to form an interwoven mesh product, which may be formed to provide a flat product or a hollow product.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of prior application Ser. No. 12/037,409, filed Feb. 26, 2008 (Attorney Docket DON09 P-1422), which is a continuation of prior application Ser. No. 11/505,268, filed on Aug. 16, 2006, now U.S. Pat. No. 7,334,925, which is a continuation of application Ser. No. 10/287,565, filed Nov. 4, 2002, now U.S. Pat. No. 7,140,755, which is a continuation of application Ser. No. 09/938,182, filed on Aug. 23, 2001, now U.S. Pat. No. 6,474,853, which is a continuation of application Ser. No. 09/630,332, filed on Jul. 31, 2000, now U.S. Pat. No. 6,280,069, which is a continuation of application Ser. No. 09/420,658, filed on Oct. 19, 1999, now U.S. Pat. No. 6,099,155, which is a continuation of application Ser. No. 09/232,316, filed on Jan. 18, 1999, now U.S. Pat. No. 6,074,077, which is a continuation of application Ser. No. 08/934,490, filed on Sep. 19, 1997, now U.S. Pat. No. 5,863,116, which is a continuation of application Ser. No. 08/607,285, filed on Feb. 26, 1996, now U.S. Pat. No. 5,669,705, which is a continuation of application Ser. No. 08/333,412, filed on Nov. 2, 1994, now U.S. Pat. No. 5,497,305, which is a continuation of application Ser. No. 08/011,947, filed on Feb. 1, 1993, now U.S. Pat. No. 5,371,659.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to security systems for vehicles and, more particularly, to remotely actuated, personal safety lighting systems. The invention is particularly adapted to incorporation in the exterior mirrors of a vehicle.
[0003] Personal security in and around vehicles has become an important concern. In particular, an increasing number of assaults and robberies are committed in parking lots while occupants are entering and exiting vehicles. While remote-operated, keyless entry systems have been incorporated in vehicles in order to unlock the vehicle and illuminate interior lights, such systems merely expedite entry to the vehicle and do not, per se, enhance security around the vehicle. Accordingly, a need exists for a vehicle security system to increase the security for vehicle occupants while entering and exiting the vehicle. Any such system would need to be aesthetically pleasing and not burdensome in use.
SUMMARY OF THE INVENTION
[0004] The present invention is intended to provide a personal safety feature for a vehicle in the form of a floodlight adapted to projecting light generally downwardly on an area adjacent a portion of the vehicle in order to create a lighted security zone in the area. Advantageously, the floodlight is preferably positioned in the housing of an exterior mirror having a reflective element also positioned in the housing. According to an aspect of the invention, an actuator is provided for the floodlight including a base unit in the vehicle and a remote transmitter. The base unit is responsive to a signal from the remote transmitter in order to actuate the floodlight. This allows the vehicle operator to actuate the floodlight from a distance in order to establish the security zone prior to approaching the vehicle.
[0005] According to another aspect of the invention, an actuator for the floodlight includes a lockout device in order to prevent actuation of the floodlight during operation of the vehicle. According to yet a further aspect of the invention, a signal light that is adapted to projecting light generally rearwardly of the vehicle is included in the exterior mirror housing. An actuator for the warning light is connected with the stoplight circuit, turn signal circuit, or both the stoplight and turn signal circuit, of the vehicle in order to actuate the warning light when either the stoplight or turn signal is being actuated.
[0006] According to yet another aspect of the invention, the floodlight is adapted to projecting a pattern of light from the housing on an area adjacent a portion of the vehicle that extends laterally onto the vehicle and downwardly and rearwardly of the vehicle. In this manner, a security zone is established from the vehicle door to the rear of the vehicle. The signal light is adapted to projecting a pattern of light extending laterally away from the vehicle and rearwardly of the vehicle. In this manner, the pattern generated by the signal light cannot be substantially observed by a driver of the vehicle. However, the pattern generated by the signal light may be observed by a driver of another vehicle passing the vehicle equipped according to the invention.
[0007] The floodlight and signal lights may be generated by a light emitting diode positioned in the housing, a vacuum fluorescent lamp positioned in the housing, an incandescent lamp positioned in the housing or a light source in the vehicle and a light pipe between the light source and the mirror housing.
[0008] By providing a lighted security zone adjacent the vehicle, users can observe suspicious activity around the vehicle. The pattern of light generated by a security light according to the invention establishes a security zone around, and even under, the vehicle in the important area where the users enter and exit the vehicle. The provision for remote actuation of the security light provides a deterrent to ward off persons lurking around the protected vehicle while the users are still at a safe distance from the vehicle. The provision for a lockout circuit ensures that the security light will not inadvertently be actuated while the vehicle is in motion. The invention, further, conveniently combines a signal light that acts in unison with the vehicle's turn signal, brake light, or both, with the security light in an exterior mirror assembly. The signal light may be designed to be observed by other vehicles passing the equipped vehicle but not directly by the driver of the equipped vehicle.
[0009] These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view taken from the front of a mirror assembly (rear of the vehicle) incorporating the invention;
[0011] FIG. 2 is a rear view of the mirror assembly in FIG. 1 ;
[0012] FIG. 3 is a top view of the mirror assembly in FIG. 1 ;
[0013] FIG. 4 is the same view of FIG. 1 of an alternative embodiment of the invention;
[0014] FIG. 5 is a block diagram of a control system according to the invention;
[0015] FIG. 6 is a block diagram of an alternative embodiment of a control system according to the invention;
[0016] FIG. 7 is a breakaway perspective view of the system in FIG. 1 revealing internal components thereof;
[0017] FIG. 8 is a sectional view taken along the lines VIII-VIII in FIG. 7 ;
[0018] FIG. 9 is a sectional view taken along the lines IX-IX in FIG. 7 ;
[0019] FIG. 10 is a side elevation of a vehicle illustrating the security zone light pattern generated by a security light according to the invention;
[0020] FIG. 11 is a top plan view of the vehicle and light pattern in FIG. 10 ;
[0021] FIG. 12 is a rear elevation of the vehicle and light pattern in FIG. 10 ;
[0022] FIG. 13 is a side elevation of a vehicle illustrating the light pattern generated by a signal light useful with the invention;
[0023] FIG. 14 is a top plan view of the vehicle and light pattern in FIG. 13 ;
[0024] FIG. 15 is a rear elevation of the vehicle and light pattern in FIG. 13 ;
[0025] FIG. 16 is the same view as FIG. 7 of a first alternative light source according to the invention;
[0026] FIG. 17 is the same view as FIG. 7 of a second alternative light source;
[0027] FIG. 18 is the same view as FIG. 7 of a third alternative light source;
[0028] FIG. 19 is the same view as FIG. 7 of a fourth alternative light source; and
[0029] FIG. 20 is the same view as FIG. 7 of the invention embodied in an alternative mirror structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Referring now specifically to the drawings, and the illustrative embodiments depicted therein, a vehicle personal security lighting system 25 includes an exterior mirror assembly 26 having a conventional reflectance element 28 , a security light 30 , preferably white, or clear, and a signal light 32 , preferably red, incorporated in a housing, or casing, 34 . Casing 34 is connected by a neck 36 to a stationary panel or sail 38 adapted for incorporation with the forward portion of the vehicle side window assembly, and which mounts mirror assembly 26 to the door of a vehicle 40 (see FIG. 10 ). Reflectance element 28 may be any of several reflectors, such as glass coated on its first or second surface with a suitable reflective layer or layers, such as those disclosed in U.S. Pat. No. 5,179,471, the disclosure of which is hereby incorporated by reference herein, or an electro-optic cell including a liquid crystal, electrochromic, or electrochemichromic fluid, gel or solid-state compound for varying the reflectivity of the mirror in response to electrical voltage applied thereacross as disclosed in U.S. Pat. No. 5,151,824, the disclosure of which is hereby incorporated by reference herein.
[0031] With reference to FIGS. 7 and 8 , as is conventional, reflectance element 28 is mounted to a bracket 43 by an actuator 42 . Casing 34 is mounted to bracket 43 . Actuator 42 provides remote positioning of reflectance element 28 on two orthogonal axes. Such actuators are well known in the art and may include a jackscrew-type actuator 42 such as Model No. H16-49-8001 (right-hand mirror) and Model No. H16-49-8051 (left-hand mirror) by Matsuyama of Kawagoe City, Japan, as illustrated in FIG. 7 , or a planetary-gear actuator 42 ′ such as Model No. 540 (U.S. Pat. No. 4,281,899) sold by Industrie Koot BV (IKU) of Montfoort, Netherlands, as illustrated in FIG. 20 . As is also conventional, the entire casing 34 including actuator 42 , 42 ′ is mounted via bracket 43 for breakaway motion with respect to stationary panel 38 by a breakaway joint assembly 44 . Breakaway joint assembly 44 ( FIG. 9 ) includes a stationary member 46 attached to vehicle 40 , a pivoting member 48 to which bracket 43 and casing 34 are attached, and a wire-way 50 through which a wire cable 52 passes. Wire cable 52 includes individual wires to supply control signals to actuator 42 , 42 ′, as well as signals to control the level of reflectivity, if reflective element 28 is of the variable reflectivity type noted above, such as an electrochromic mirror. Power may also be supplied through cable 52 for a heater (not shown) as disclosed in U.S. Pat. No. 5,151,824 in order to evaporate ice and dew from reflective element 28 .
[0032] With reference to FIG. 5 , actuator 42 , 42 ′ receives a first set of reversible voltage signals from a switch 54 , in order to bidirectionally pivot in one axis, and a second set of reversible signals from a switch 56 , in order to bidirectionally pivot in the opposite axis, as is conventional. Switches 54 and 56 are actuated by a common actuator (not shown) that is linked so that only one of the switches 54 and 56 may be actuated at a time. In this manner, actuator 42 , 42 ′ may utilize one common conductor for both switches 54 , 56 .
[0033] Each of the security light 30 and signal light 32 includes a light source 60 and reflector 62 behind a lens 64 ( FIG. 8 ). Light source 60 , reflector 62 and lens 64 are designed for security light 30 to project a pattern 66 of light, such as white light, through a clear, non-filtering lens, in order to establish a security zone around the vehicle ( FIGS. 10-12 ). Pattern 66 extends rearward from mirror assembly 26 . Vertically, pattern 66 contacts the ground at 68 in the vicinity of entry and exit by the vehicle occupants ( FIGS. 10 and 12 ). Laterally, pattern 66 fans out into contact with the side 70 a , 70 b of the vehicle. This contact washes the sides of the vehicle to reflect the light in order to further illuminate the area in order to establish the security lighting zone ( FIGS. 11 and 12 ). In a preferred embodiment, pattern 66 extends rearwardly from mirror assembly 26 without projecting any portion of the pattern forwardly of the mirror assembly.
[0034] Signal light 32 generates a light pattern 72 , which is directed generally horizontally rearwardly of vehicle 40 ( FIGS. 13-15 ). Pattern 72 is laterally directed substantially away from side 70 a , 70 b of vehicle 40 so that the driver of vehicle 40 does not directly intercept pattern 72 , although a minor intensity (such as 10%) of the pattern is intercepted by the driver in order to provide awareness of the actuating of the signal light. Pattern 72 fans laterally away from side 70 a , 70 b to an extent that is parallel the face of reflectance element 28 , which is substantially perpendicular to side 70 a , 70 b ( FIG. 14 ). Thus, the driver of another vehicle (not shown) passing vehicle 40 on the left or right side of vehicle 40 will intercept pattern 72 while the vehicle is behind and beside vehicle 40 . Although, in an illustrated embodiment, lens 64 of signal light 32 is substantially planar, lens 64 of signal light 32 could be made to wrap around the outward side of casing 34 in order to function as a side marker for the vehicle as is required in some European countries.
[0035] Vehicle mirror assembly security system 25 is actuated by a control system 74 ( FIG. 5 ). Control system 74 includes means for actuating security light 30 including a remote transmitting device 76 and a stationary receiving device 78 . Transmitting device 76 may be remotely carried by the vehicle operator and includes switches 80 and 81 in order to actuate the transmitting circuitry to transmit a signal form antenna 82 , which is received by antenna 84 of receiving device 78 . Receiving device 78 is mounted in the vehicle, such as in the vehicle trunk compartment, and includes an output 86 in order to operate remote door lock circuit 88 , as is conventional. Output 86 is, additionally, provided as an input 90 of a lockout circuit 92 , whose output 94 is supplied to security lamp 30 . Input 90 may additionally be actuated by a timeout circuit 96 , which is conventionally supplied in a vehicle in order to dim the interior lights, following a slight delay, after the occurrence of an event, such as the opening and closing of the doors of the vehicle. Signal light 32 is actuated on line 98 from either a turn indicator circuit 100 or a stop lamp indicator circuit 102 , both of which are conventionally supplied with vehicle 40 .
[0036] In operation, when the operator actuates switch 80 of transmitting device 76 , receiving device 78 produces a signal on output 86 in order to cause remote door lock circuit 88 to unlock the doors. Alternatively, actuation of switch 81 on remote transmitting device 76 causes receiving device 78 to produce a signal on output 86 to cause remote door lock circuit 88 to lock the vehicle doors. The signal on output 86 actuates security lamp 30 provided that lockout circuit 92 does not inhibit the signal. Lockout circuit 92 responds to operation of the vehicle in order to avoid actuation of security lamp 30 when the vehicle is in motion. Such lockout circuits are conventional and may be responsive to placing of the vehicle transmission in gear of sensing of the speed of the vehicle, or the like. Security lamp 30 is also actuated, in response to interior lighting device timeout circuit 96 , whenever the interior lights of the vehicle are being actuated by timeout circuit 96 , provided that lookout circuit 92 does not inhibit the signal from security lamp 30 . This is provided in order to allow security lamp 30 to be actuated in response to the entry to, or exit from, vehicle 40 without the operator utilizing transmitting device 76 to lock or unlock the doors. Signal lamp 32 is actuated in response to turn indicator circuit 100 whenever the operator moves the indicator stick in the direction of that particular signal lamp 32 . Signal lamp 32 may additionally be actuated from stop lamp circuit 102 in response to the driver actuating the vehicle's brakes.
[0037] In the embodiment illustrated in FIGS. 1 and 5 , lens 64 of signal lamp 32 is adapted to filter the light provided from lamp 32 so as to be red and is provided for vehicles 40 in which the stop lamps and rear turn indicator lamps are, likewise, red. Because signal lamp 32 shines red, pattern 72 is restricted from extending forward of the vehicle. This is in order to comply with regulations prohibiting red lights from causing confusion with emergency vehicles by shining forward of the vehicle.
[0038] For vehicles having red stoplights and amber turn indicators in the rear, a vehicle mirror security assembly 25 ′ includes an exterior mirror assembly 26 ′ and a control system 74 ′ ( FIGS. 4 and 6 ). Exterior mirror assembly 26 ′ includes a security light 30 ′, preferably white or clear, and a pair of signal lights 32 a ′ and 32 b ′. Signal light 32 a ′ is amber and is actuated directly from turn indicator circuit 100 ′. This amber color can be provided either by an amber light bulb or source, or a filtering lens providing an amber color. Signal light 32 b ′ is red and is actuated directly from stop lamp circuit 102 ′. Each of the light patterns generated by signal lights 32 a ′ and 32 b ′ substantially correspond with light pattern 72 . The light pattern generated by security light 30 ′ is substantially equivalent to pattern 66 . With the exception that turn signal indicator circuit 100 ′ actuates signal light 32 a ′ and stop lamp circuit 102 ′ actuates signal light 32 b ′, control system 74 ′ operates substantially identically with control circuit 74 .
[0039] In the illustrated embodiment, light source 60 , for both security light 30 and signal light 32 , may be supplied as a conventional incandescent or halogen lamp 60 a ( FIG. 7 ). Alternatively, a conventional incandescent fuse lamp 60 b may be used ( FIG. 16 ). Alternatively, a vacuum fluorescent lamp 60 c , which is available in various colors, may be used ( FIG. 17 ). Alternatively, a light emitting diode 60 d may be used ( FIG. 18 ). As yet a further alternative, a fiber optic bundle 104 forming a light pipe may be positioned to discharge light behind lens 64 . Fiber optic bundle 104 passes through breakaway joint 44 in wire-way 50 in order to transmit light from a source (not shown) within vehicle 40 . By way of example, lens 64 may be supplied as a segmented lens, a prismatic lens, or a Fresnel lens in order to generate light patterns 66 and 72 . Bracket 43 and breakaway joint 44 are marketed by Donnelly Corporation, the present assignee, of Holland, Mich. The remote actuator composed of remote transmitting device 76 and stationary receiving device 78 may be radio frequency coupled, as is conventional. Alternatively, they may be infrared coupled as illustrated in U.S. Pat. No. 4,258,352.
[0040] Although the invention is illustrated in a mirror assembly utilizing an automatic remote actuator, it may also be applied to manual remote actuators and handset actuators. As previously set forth, reflectance element 28 may be conventional or may be supplied as an electrochromic self-dimming mirror. Although the invention is illustrated with breakaway joint 44 , the invention may also be applied to mirrors that are rigidly mounted to the vehicle.
[0041] Changes and modifications in the specifically described embodiments can be carried out without departing form the principles of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the Doctrine of Equivalents.
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A lighted exterior rearview mirror system includes an exterior rearview mirror assembly including a reflective element and an electrically-operable actuator. The exterior rearview mirror assembly includes a breakaway joint assembly. The reflective element has an electrically powered heater operable to remove ice or dew from the reflective element. The exterior rearview mirror assembly includes a turn signal indicator lamp that has a light source and a lens. The lamp is included in the exterior rearview mirror assembly and unaffected by operation of the actuator. The breakaway joint assembly includes a wire-way through which a wire cable passes. The wire cable includes wires for operating the actuator, the heater and the lamp. The lens of the lamp has a portion that faces rearward of the vehicle and a portion that wraps around an outward side of a casing of the exterior rearview mirror assembly.
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BACKGROUND OF THE INVENTION
The present invention relates to integrated circuit (IC) memory devices and, more particularly, to the inclusion of one or more thin layers, such as Si, Al, IrO 2 , or Al plus TiN, as an adhesion layer between a noble metal layer, such as Pt, and a silicon dioxide (SiO 2 )layer to form the electrode for high-k dielectric Dynamic Random Access Memory (DRAM) and Ferroelectric Random Access Memory (FRAM) applications.
Capacitors with high dielectric constant (high-k) materials as the dielectric are increasingly used in high density devices. The high-k dielectrics used in DRAM devices are generally formed at a high temperature oxidation ambient, as are ferroelectric materials used in FRAM devices. To avoid oxidation of the electrodes at these high temperatures, noble metal electrodes are used with the dielectric. Platinum (Pt) electrodes are typically used for the high-k dielectric capacitors in DRAM devices and for FRAM devices because of its excellent oxidation resistance and high work function. However, Pt poorly adheres to silicon dioxide and results in peeling of the Pt at various process steps, such as during the formation of the capacitor and during the following Back End of Line (BEOL) processes. To prevent peeling, an intermediate adhesion layer may be added between the Pt and SiO 2 layers. Currently, the adhesion layers used include Ti, TaSiN or TiN.
Though these materials can improve the adhesion between the Pt and SiO 2 layers in the “as-deposited” state, roughening of the Pt surface or a local peeling has been observed after the subsequent annealing step which is typically at a temperature of 500 to 580° C. in an oxygen ambient. Further, when high-k dielectric and ferroelectric layers are deposited at temperatures below 500° C., the layers have degraded film quality with decreased capacitance, which degrades the performance of the device.
It is therefore desirable to provide an improved adhesion layer between the noble metal electrodes and the SiO 2 layers. It is also desirable to provide an adhesion layer that prevents the peeling of the noble metal electrodes of the capacitor structures.
SUMMARY OF THE INVENTION
The present invention provides one or more adhesion layers which prevent the Pt electrode from peeling from the SiO 2 . Such layers include IrO 2 , Si, Al, or Al plus TiN as the adhesion layer.
According to an aspect of the invention, in a semiconductor capacitor structure formed on a silicon dioxide (SiO 2 ) substrate and having a noble metal electrode, an adhesion layer is disposed between the electrode and the SiO 2 substrate. The adhesion layer is selected from a group consisting of silicon (Si), aluminum (Al), aluminum (Al) plus titanium nitride (TiN) and iridium oxide (IrO 2 ).
According to a further aspect of the invention, an adhesion layer is selected from a group consisting of Si, Al, Al plus TiN, and IrO 2 and is disposed between a noble metal layer and a silicon dioxide layer.
According to another aspect of the invention, a high dielectric constant (high-k) capacitor structure is fabricated. An adhesion layer is deposited on a SiO2 substrate. The adhesion layer is selected from a group consisting of Si, Al, Al plus TiN, and IrO 2 . A noble metal bottom electrode is deposited on the adhesion layer.
In accordance with this aspect of the invention, a high-k dielectric material is deposited on the bottom electrode. A top electrode is deposited on the high-k dielectric layer, and the top electrode and the high-k dielectric are patterned. An insulation layer is deposited thereon, and vias are opened in the insulation layer. A metal pad layer is deposited in the vias and atop the insulation layer, and the metal pad layer is patterned.
According to a still further aspect of the invention, a 3-dimensional capacitor structure is fabricated. A silicon dioxide layer is deposited on a substrate, and vias are opened in the silicon dioxide layer. Polycrystalline silicon is deposited into the vias, and the polycrystalline silicon is planarized and recessed back to form poly plugs in the vias. A barrier layer is deposited in the vias, and the barrier layer is planarized. An adhesion layer is deposited atop the barrier layer and the SiO 2 layer. The adhesion layer is selected from a group consisting of Si, Al, Al plus TiN, and IrO 2 . A noble metal bottom electrode is deposited on the adhesion layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of the invention with reference to the drawings in which:
FIG. 1 is a graph illustrating x-ray diffraction analysis data and showing the stability of IrO 2 at temperatures of up to 750° C.
FIG. 2 is a cross-sectional view showing a planar capacitor structure of a device according to an embodiment of the invention.
FIG. 3 is a cross-sectional view showing a first three-dimensional capacitor structure of a device according to another embodiment of the invention.
FIG. 4 is a cross-sectional view showing a second three-dimensional capacitor structure of a device according to a further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention is directed to the use of one or more layers, such as IrO 2 , Si and Al plus TiN, that improve adhesion between an electrode layer and a SiO2 layer.
IrO 2 , as an example, has a good adhesion to silicon oxide as can be predicted by its oxygen bonding nature. IrO 2 remains stable up to 750° C. when exposed to an oxygen ambient, as shown in FIG. 1 . Further, polycrystalline IrO 2 is conductive and can serve as a part of the electrode.
Alternatively, thin Si or Al layers can form a uniform thin silicon oxide or aluminum oxide layer underneath a Pt electrode to improve the adhesion of Pt on SiO 2 layer without decreasing dielectric film quality on the Pt.
TABLE 1
Adhesion Test Results
Adhesion Layer and
Thickness
Pt Thickness
Adhesion (Mpam1/2)
None
1000 Å
Failed
TiN, CVD, 50 Å
1000 Å
<0.16
TaSiN, 250 Å
2500 Å
0.24
Ti, PVD, 50 Å
1000 Å
0.26
Al, 100 Å
1000 Å
0.23
Al, 100 Å, +Ti, 200 Å
1000 Å
0.32
Poly Si, 50 Å
1000 Å
0.30
Table 1 shows the adhesion properties of various materials after exposure in an oxygen ambient at 640° C. for five minutes. Samples with a known chemical vapor deposited (CVD) TiN adhesion layer could not be tested since its adhesion was less than 0.16. Samples with known Ti or TaSiN adhesion layers had improved adhesion over the CVD physical vapor deposition (PVD) but were not suitable because of dielectric layer degradation on a Pt/Ti or TaSiN/SiO 2 structure. Better or at least comparable adhesion was obtained for samples with a polycrystalline Si, Al, or Al plus Ti adhesion layers of the invention.
To test the adhesion, a planar capacitor structure, such as is shown in FIG. 2 , was prepared by first depositing an adhesion layer 21 on a SiO 2 layer atop a substrate (not shown). The adhesion layer is preferably Si, Al, Al plus Ti or IrO 2 . A Pt bottom electrode 23 is then deposited atop the adhesion layer 21 . A high-k dielectric 24 is then deposited atop the adhesion layer, and a top electrode 25 (Pt) is deposited thereon. The high-k dielectric may be a (Ba,Sr)TiO 3 (BST) material. The top electrode 25 and the high-k dielectric 24 are then patterned and an insulation (SiO 2 ) layer 26 is thereafter deposited atop this structure. Vias are then opened in the SiO 2 , and a Al or W a metal pad layer 27 is deposited in and on top of the vias and is then patterned.
Electrical testing results using the planar capacitor structure shown in FIG. 2 show essentially no change in the capacitance of the dielectric layer when using a poly Si adhesion layer, as Table 2 shows.
TABLE 2
Electrical Test Results
Adhesion Layer
Capacitance (pF)
None
350-400
Poly Si, 50 Å
350-400
The adhesion layers of the invention may be used in any integration scheme where adhesion of the electrode to the SiO 2 layer is of importance. Without limiting the scope of the invention, two examples using three-dimensional capacitor structures on devices for a DRAM application are now described.
Referring to FIG. 3 , a SiO 2 layer 31 is formed on a device substrate (not shown). Vias are opened in the SiO 2 layer 31 , and a polycrystalline Si layer 32 is deposited on top of the SiO 2 and into the vias. The polycrystalline Si is planarized to remove any material atop the SiO 2 layer, using a chemical mechanical polish (CMP) process, and the polysilicon is then recessed back, leaving poly plugs in the vias between the surface of the SiO 2 layer. Next, a barrier layer 33 is deposited atop the SiO 2 layer and the poly plugs, and the barrier layer is likewise subjected to a CMP process. An adhesion layer 34 is then deposited, and a Pt bottom electrode 35 is deposited atop the adhesion layer. If a conductive adhesion layer is used, such as IrO 2 the bottom electrode is deposited directly onto the adhesion layer. Alternatively, if a non-conductive adhesion layer is used, the part of the adhesion layer that is over the barrier layer is removed, and then the bottom electrode 35 is then deposited. Thereafter, the bottom electrode layer is patterned to form a three-dimensional structure (not shown). A high-k dielectric, such as BST, is then deposited and is covered with Pt top electrode layer to form the capacitor structure.
An alternative three-dimensional structure is shown in FIG. 4 . First, a SiO 2 layer 41 is deposited on a device substrate (not shown). Vias are then opened in the SiO 2 layer, and a polycrystalline Si layer 42 is formed in the vias and atop the SiO 2 . The polycrystalline Si is then planarized using a CMP process and recessed back, thereby leaving poly plugs in the vias. Next, a barrier layer 43 is deposited and subjected to a CMP process. A SiO 2 layer 44 is deposited and then patterned to form a three-dimensional structure, and an adhesion layer 45 is deposited thereon. A bottom (Pt) electrode 46 is deposited directly on the adhesion layer when the adhesion layer is conductive, such as when IrO 2 is used. Alternatively, the adhesion layer is removed in the regions above the barrier layer 43 and the bottom electrode is thereafter deposited. The top planar part of the bottom electrode 46 is then removed (not shown), and a high-k dielectric, such as BST, is deposited and covered with a Pt layer to form capacitors.
While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims.
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Si, Al, Al plus TiN, and IrO2 are used as adhesion layers to prevent peeling of noble metal electrodes, such as Pt, from a silicon dioxide (SiO 2 ) substrate in capacitor structures of memory devices.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Japanese Patent Application No. 2012-187241 filed Aug. 28, 2012, the content of which is hereby incorporated herein by reference in its entirety.
BACKGROUND
The present disclosure relates to a sewing machine that can sew an embroidery pattern on a sewing workpiece held by an embroidery frame, and to a non-transitory computer-readable medium.
In a sewing machine that has a function of sewing an embroidery pattern on a sewing workpiece held by an embroidery frame, various functions that set a layout of the embroidery pattern on the sewing workpiece are being considered. In a known sewing machine, in a case where a plurality of embroidery patterns are combined and sewn, when an embroidery pattern that is first in sewing order is sewn, a stitch that indicates a reference position of the embroidery pattern is sewn.
SUMMARY
In the known sewing machine, when the position of at least one stitch to be sewn is adjusted with respect to at least one sewn stitch, a user has to arrange the stitch indicating the reference position in a position that is to be a needle drop point when sewing of each embroidery pattern is started, and thus the position adjustment operation is troublesome.
Embodiments of the broad principles derived herein provide a sewing machine capable of easily performing position adjustment of at least one stitch to be sewn with respect to at least one sewn stitch, and a non-transitory computer-readable medium.
Embodiments provide a sewing machine that includes a sewing device, a processor, and a memory. The sewing device is configured to form stitches on a sewing workpiece held by an embroidery frame. The memory is to store computer-readable instructions that, when executed by the processor, instruct the processor to perform processes including: acquiring embroidery data, the embroidery data being data to sew an embroidery pattern on the sewing workpiece, the embroidery pattern being formed by a plurality of stitches; generating stitched marker data based on the acquired embroidery data, the stitched marker data being data to form at least one stitched marker in a position where the at least one stitched marker is covered by the embroidery pattern, and each of the at least one stitched marker being formed by at least one stitch used as a reference for at least one of a first sewing position and a first sewing angle of the embroidery pattern; causing the sewing device to sew the at least one stitched marker in accordance with the generated stitched marker data; causing the sewing device to start sewing the embroidery pattern in accordance with the acquired embroidery data; identifying a pattern to be sewn when the sewing of the embroidery pattern is stopped, the pattern to be sewn having at least one stitch included in the plurality of stitches of the embroidery pattern and not yet sewn; detecting at least one of a second sewing position and a second sewing angle of the at least one stitched marker on the sewing workpiece when the sewing of the embroidery pattern is stopped; setting at least one of a third sewing position and a third sewing angle of the identified pattern to be sewn, in accordance with at least one of a fourth sewing position and a fourth sewing angle of a sewn pattern on the sewing workpiece, based on the detected at least one of the second sewing position and the second sewing angle, the sewn pattern having at least one sewn stitch that is included in the plurality of stitches of the embroidery pattern; correcting data to be used to sew the pattern to be sewn included in the embroidery data based on the set at least one of the third sewing position and the third sewing angle; and causing the sewing device to restart sewing the embroidery pattern in accordance with the embroidery data including the corrected data for the pattern to be sewn.
Embodiments farther provide a non-transitory computer-readable medium storing computer-readable instructions. The computer-readable instructions, when executed, instruct a processor of a sewing machine to perform processes including: acquiring embroidery data, the embroidery data being data to sew an embroidery pattern on a sewing workpiece held by an embroidery frame, the embroidery pattern being formed by a plurality of stitches; generating stitched marker data based on the acquired embroidery data, the stitched marker data being data to form at least one stitched marker in a position where the at least one stitched marker is covered by the embroidery pattern, and each of the at least one stitched marker being formed by at least one stitch used as a reference for at least one of a first sewing position and a first sewing angle of the embroidery pattern; causing a sewing device to sew the at least one stitched marker in accordance with the generated stitched marker data, the sewing device being configured to form stitches on the sewing workpiece held by an embroidery frame; causing the sewing device of the sewing machine to start sewing the embroidery pattern in accordance with the acquired embroidery data; identifying a pattern to be sewn when the sewing of the embroidery pattern is stopped, the pattern to be sewn having at least one stitch included in the plurality of stitches of the embroidery pattern and not yet sewn; detecting at least one of a second sewing position and a second sewing angle of the at least one stitched marker on the sewing workpiece when the sewing of the embroidery pattern is stopped; setting at least one of a third sewing position and a third sewing angle of the identified pattern to be sewn, in accordance with at least one of a fourth sewing position and a fourth sewing angle of a sewn pattern on the sewing workpiece, based on the detected at least one of the second sewing position and the second sewing angle, the sewn pattern having at least one sewn stitch that is included in the plurality of stitches of the embroidery pattern; correcting data to be used to sew the pattern to be sewn included in the embroidery data based on the set at least one of the third sewing position and the third sewing angle; and causing the sewing device to restart sewing the embroidery pattern in accordance with the embroidery data including the corrected data for the pattern to be sewn.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments will be described below in detail with reference to the accompanying drawings in which:
FIG. 1 is an oblique view of a sewing machine;
FIG. 2 is an explanatory diagram showing a lower end portion of a head and an internal configuration of the head;
FIG. 3 is a block diagram that shows an electrical configuration of the sewing machine;
FIG. 4 is an explanatory diagram of a stitched marker;
FIG. 5 is an explanatory diagram representing an order of sewing of embroidery patterns;
FIG. 6 is a flowchart of main processing;
FIG. 7 is a flowchart of stitched marker sewing processing that is performed in the main processing shown in FIG. 6 ;
FIG. 8 is an explanatory diagram of an embroidery pattern image that is represented by data that is generated by the stitched marker sewing processing shown in FIG. 7 ;
FIG. 9 is an explanatory diagram of a stitched marker image that is represented by the data that is generated by the stitched marker sewing processing shown in FIG. 7 ;
FIG. 10 is an explanatory diagram of an image obtained by overlapping the embroidery pattern image and the stitched marker image;
FIG. 11 is an explanatory diagram of a feature point image that is represented by data that is generated by the main processing shown in FIG. 6 ;
FIG. 12 is an explanatory diagram of a captured image that is represented by image data that is acquired by the main processing shown in FIG. 6 ;
FIG. 13 is an explanatory diagram of an arrangement of a plurality of feature points that are detected based on the image data that represents the captured image shown in FIG. 12 ; and
FIG. 14 is an explanatory diagram of processing that sets a sewing position and a sewing angle of a pattern to be sewn with respect to a sewn pattern.
DETAILED DESCRIPTION
Hereinafter, embodiments will be explained with reference to the drawings. First, a physical configuration of a sewing machine 1 will be explained with reference to FIG. 1 and FIG. 2 . The upper side, the lower side, the lower left side, the upper right side, the upper left side and the lower right side of FIG. 1 are respectively defined as the upper side, the lower side, the left side, the right side, the rear side, and the front side of the sewing machine 1 . More specifically, a surface on which a plurality of operation switches 21 are arranged is the front face of the sewing machine 1 . The longitudinal direction of a bed 11 and an arm 13 is the left-right direction of the sewing machine 1 , and the side on which a pillar 12 is arranged is the right side. The extending direction of the pillar 12 is the up-down direction of the sewing machine 1 .
The sewing machine 1 is provided with the bed 11 , the pillar 12 , and the arm 13 . The bed 11 is a base portion of the sewing machine 1 and extends in the left-right direction. The pillar 12 extends upward from the right end of the bed 11 . The arm 13 extends to the left from the upper end of the pillar 12 such that the arm 13 faces the bed 11 . The left end of the arm 13 is a head 14 . A needle plate (not shown in the drawings) is disposed on a top surface of the bed 11 . Below the needle plate (namely, inside the bed 11 ), a feed dog (not shown in the drawings), a feed mechanism 87 (refer to FIG. 3 ), a shuttle mechanism (not shown in the drawings) and a feed adjustment motor 77 (refer to FIG. 3 ) are provided as structural elements of a sewing mechanism 89 (refer to FIG. 3 ) that forms stitches on a sewing workpiece 100 . The feed dog may be driven by the feed mechanism 87 , and may move the sewing workpiece (a work cloth, for example) by a predetermined feed distance. The feed distance of the feed dog may be adjusted by the feed adjustment motor 77 . The shuttle mechanism is configured to entwine a needle thread with a bobbin thread below the needle plate.
As shown in FIG. 2 , a needle bar 29 and a presser bar 31 extend downward from a lower end portion of the head 14 . A sewing needle 28 may be replaceably attached to the lower end of the needle bar 29 . A presser foot 30 may be replaceably attached to the lower end of the presser bar 31 . The presser foot 30 may hold the sewing workpiece in place. A needle bar mechanism (not shown in the drawings), a needle swinging mechanism 88 (refer to FIG. 3 ) and a needle swinging motor 80 (refer to FIG. 3 ) and the like are provided on the head 14 as structural elements of the sewing mechanism 89 (refer to FIG. 3 ). The needle bar mechanism is configured to drive the needle bar 29 to move in the up-down direction. The needle bar mechanism may be driven by a drive shaft 81 (refer to FIG. 3 ) that may be driven by a sewing machine motor 79 (refer to FIG. 3 ). The needle swinging mechanism 88 is configured to swing the needle bar 29 in the left-right direction. The needle swinging mechanism 88 may be driven by the needle swinging motor 80 .
An image sensor 90 is attached to the head 14 , at a position forward of the needle bar 29 and slightly to the right of the needle bar 29 such that the image sensor 90 can capture an image of the entire needle plate (not shown in the drawings). The image sensor 90 is provided with a complementary metal oxide semiconductor (CMOS) sensor and a control circuit. The image sensor 90 is configured to generate image data that represents the image captured by the CMOS sensor. In the present embodiment, a support frame 99 is attached to a sewing machine frame (not shown in the drawings) of the sewing machine 1 . The image sensor 90 is fixed to the support frame 99 . The image data generated by the image sensor 90 may be used in main processing that will be described later.
As shown in FIG. 1 , a cover 16 that can be opened and closed is provided on an upper portion of the arm 13 . In FIG. 1 , the cover 16 is in an open state. A thread housing portion 18 is provided below the cover 16 , namely, inside the arm 13 . The thread housing portion 18 is provided with a thread spool pin 19 that extends in the left-right direction. A thread spool 20 is housed in the thread housing portion 18 such that the thread spool pin 19 passes through the thread spool 20 . The needle thread (not shown in the drawings) that is wound around the thread spool 20 is supplied to the sewing needle 28 attached to the needle bar 29 via a thread hook (not shown in the drawings) provided on the head 14 . The plurality of operation switches 21 including a start/stop switch are provided on a lower portion of a front face of the arm 13 .
A liquid crystal display (hereinafter referred to as an LCD) 15 is provided on a front face of the pillar 12 . The LCD 15 displays an image that includes various items, such as commands, illustrations, setting values and messages. A touch panel 26 is provided on a front face side of the LCD 15 . When a user performs a pressing operation (hereinafter this operation is referred to as a “panel operation”) on the touch panel 26 using a finger or a dedicated stylus pen, which item is selected is recognized corresponding to the pressed position detected by the touch panel 26 . Through this type of panel operation, the user can select a pattern to be sewn and a command to be executed.
A connector 38 (refer to FIG. 3 ) is provided on a right side surface of the pillar 12 . An external storage device (not shown in the drawings), such as a memory card, can be connected to the connector 38 . The sewing machine 1 can fetch embroidery data and various programs (which will be described later) from the external storage device connected to the connector 38 .
The sewing machine 1 further includes an embroidery device 2 . The embroidery device 2 can be mounted on and removed from the bed 11 . FIG. 1 shows a state in which the embroidery device 2 is mounted on the sewing machine 1 . When the embroidery device 2 is mounted on the sewing machine 1 , the embroidery device 2 and the sewing machine 1 are electrically connected. When the embroidery device 2 and the sewing machine 1 are electrically connected, the embroidery device 2 may function as a part of the sewing mechanism 89 (refer to FIG. 3 ) of the sewing machine 1 . The embroidery device 2 is provided with a body 51 and a carriage 52 .
The carriage 52 is provided above the body 51 . The carriage 52 has a rectangular parallelepiped shape that is long in the front-rear direction. The carriage 52 is provided with a frame holder (not shown in the drawings), a Y axis moving mechanism 86 (refer to FIG. 3 ) and a Y axis motor 84 (refer to FIG. 3 ). An embroidery frame 53 can be attached to and removed from the frame holder. Although not shown in the drawings, a plurality of types of the embroidery frame that are different in size and shape are prepared. The frame holder is provided on a right side surface of the carriage 52 . Although not shown in detail, the embroidery frame 53 has a known structure and holds a sewing workpiece 100 between an inner frame and an outer frame of the embroidery frame 53 . The sewing workpiece 100 held by the embroidery frame 53 may be arranged above the bed 11 and below the needle bar 29 and the presser foot 30 . The Y axis moving mechanism 86 is configured to move the frame holder in the front-rear direction (Y direction). As the frame holder is moved in the front-rear direction, the embroidery frame 53 moves the sewing workpiece 100 in the front-rear direction. The Y axis motor 84 may drive the Y axis moving mechanism 86 . A CPU 61 (refer to FIG. 3 ) of the sewing machine 1 may control the Y axis motor 84 .
The body 51 is internally provided with an X axis moving mechanism 85 (refer to FIG. 3 ) that is configured to move the carriage 52 in the left-right direction (X direction) and an X axis motor 83 (refer to FIG. 3 ). As the carriage 52 is moved in the left-right direction, the embroidery frame 53 moves the sewing workpiece 100 in the left-right direction. The X axis motor 83 may drive the X axis moving mechanism 85 . The CPU 61 of the sewing machine 1 may control the X axis motor 83 .
The sewing mechanism 89 moves the embroidery frame 53 in the left-right direction (X direction) and the front-rear direction (Y direction), and drives the needle bar 29 shown in FIG. 2 and the shuttle mechanism (not shown in the drawings) synchronized with the motion of the embroidery frame 53 , and thereby sews an embroidery pattern on the sewing workpiece 100 held by the embroidery frame 53 . When a normal practical pattern that is not an embroidery pattern is sewn, the sewing is performed while the sewing workpiece 100 is being moved by the feed dog (not shown in the drawings) in a state in which the embroidery device 2 is removed from the bed 11 .
An electrical configuration of the sewing machine 1 will be explained with reference to FIG. 3 . A control portion 60 of the sewing machine 1 is provided with the CPU 61 , a ROM 62 , a RAM 63 , a flash ROM 64 , an external access RAM 65 and an input/output interface 66 . The CPU 61 , the ROM 62 , the RAM 63 , the flash ROM 64 , the external access RAM 65 and the input/output interface 66 are mutually electrically connected via a bus 67 . The ROM 62 may store data and various programs including a program that is used by the CPU 61 to execute the main processing that will be described later. The flash ROM 64 may store a plurality of types of embroidery data that are used by the sewing machine 1 to sew an embroidery pattern, and various types of parameters etc. to extract feature points from the image data generated by the image sensor 90 . The connector 38 is connected to the external access RAM 65 .
The operation switches 21 , the touch panel 26 , the image sensor 90 and drive circuits 71 to 76 are electrically connected to the input/output interface 66 . The drive circuits 71 to 76 respectively drive the LCD 15 , the sewing machine motor 79 , the X axis motor 83 , the Y axis motor 84 , the feed adjustment motor 77 and the needle swinging motor 80 .
A stitched marker 150 will be explained with reference to FIG. 4 . The left-right direction and the up-down direction in FIG. 4 respectively correspond to the X direction and the Y direction of the sewing machine 1 . The stitched marker 150 is formed by stitches, and may be used as a reference for at least one of a sewing position and a sewing angle of an embroidery pattern. In the present embodiment, the sewing position and the sewing angle of the embroidery pattern are represented by the stitched marker 150 . At least one of the sewing position and the sewing angle of a pattern (stitches) is defined as a layout of the pattern (stitches). Particularly, in the present embodiment, the layout of the pattern (stitches) indicates the sewing position and the sewing angle of the pattern (stitches). When sewing of an embroidery pattern including a plurality of stitches is stopped in the main processing that will be described later, the stitched marker 150 is used as a reference to set the layout of a pattern to be sewn with respect to a sewn pattern. The sewn pattern includes at least one stitch that has been sewn among a plurality of stitches that form the embroidery pattern. The pattern to be sewn includes at least one stitch that has not been sewn among the plurality of stitches that form the embroidery pattern. As shown in FIG. 4 , the stitched marker 150 has a cross shape and includes four stitches 151 to 154 that extend in the X direction and four stitches 155 to 158 that extend in the Y direction. The length of the stitched marker 150 in the X direction indicated by an arrow 159 and the length of the stitched marker 150 in the Y direction indicated by an arrow 160 may be each 4 mm, for example. The sewing position of the stitched marker 150 is set to a position where the stitched marker 150 will be covered by the embroidery pattern, in accordance with the main processing that will be described later. Unit data of the stitched marker 150 may be stored in the flash ROM 64 . The unit data is data that represents relative coordinates to be used to sew the stitches 151 to 158 that form the stitched marker 150 . The relative coordinates are represented by coordinates in an embroidery coordinate system. The embroidery coordinate system is a coordinate system of the X axis motor 83 and the Y axis motor 84 that may cause the carriage 52 to move. By using coordinates in the embroidery coordinate system, it is possible to represent a position on the sewing workpiece 100 held by the embroidery frame 53 .
Using an embroidery pattern 200 as an example, the embroidery pattern formed by a plurality of stitches that can be sewn using the sewing machine 1 and the embroidery data will be explained with reference to FIG. 5 . The user can select a desired embroidery pattern by the panel operation from among a plurality of embroidery patterns stored in the flash ROM 64 (refer to FIG. 3 ). The embroidery pattern 200 is an embroidery pattern that is sewn using three colors of thread. In accordance with the embroidery data, the embroidery pattern 200 is sewn in the order of a pattern 201 of a first color, a pattern 202 of a second color and a pattern 203 of a third color. The embroidery data to sew the embroidery pattern 200 includes a data number, coordinate data and thread color data. The data number represents the number of needle drop points from the start of sewing. The coordinate data is data that represents positions (specifically, needle drop points) of the stitches included in the embroidery pattern. For example, the coordinate data represents relative coordinates of an (N+1)-th needle drop point with respect to an N-th needle drop point, namely, an X axis movement amount and a Y axis movement amount of the embroidery frame 53 , or represents absolute coordinates in the embroidery coordinate system of the stitches included in the embroidery pattern. The needle drop point is a position at which the sewing needle 28 pierces the sewing workpiece 100 . The coordinate data defines the layout and the size of the embroidery pattern. The coordinate data of the embroidery data is corrected as appropriate when the layout and the size of the embroidery pattern with respect to the sewing workpiece 100 are changed. In the present embodiment, the embroidery coordinate system and a coordinate system for the whole of space (hereinafter referred to as a world coordinate system) are associated in advance. The sewing machine 1 has a function to correct the coordinate data represented by the embroidery coordinate system, using coordinates represented by the world coordinate system. The thread color data is data that represents the color of thread used to sew stitches.
Hereinafter, the main processing of the present embodiment will be explained with reference to FIG. 6 to FIG. 9 . The main processing is started, for example, when the user selects an embroidery pattern by the panel operation and inputs a command to start sewing of the embroidery pattern after editing the embroidery pattern and specifying the layout of the embroidery pattern. When the main processing is started, the sewing workpiece 100 is held by the embroidery frame 53 and the embroidery frame 53 is mounted on the embroidery device 2 . When the main processing is started, the thread of the first color of the embroidery pattern is mounted on the sewing machine 1 . The program to perform the main processing is stored in the ROM 62 (refer to FIG. 3 ) and is performed by the CPU 61 . In the explanation below, an image represented by the image data that is generated by the image sensor 90 and is output to the control portion 60 is referred to as a captured image. The data that is acquired or calculated in the course of performing the main processing is stored in the RAM 63 , as appropriate. As a specific example, a case will be explained in which the sewing workpiece 100 is removed from the embroidery frame 53 in the middle of sewing the embroidery pattern 200 .
As shown in FIG. 6 , in the main processing, the CPU 61 acquires, from the flash ROM 64 , the embroidery data to sew the embroidery pattern 200 selected by the user (step S 1 ). The editing and the specified layout of the embroidery pattern are reflected in the embroidery data acquired by the processing at step S 1 . Next, the CPU 61 performs stitched marker sewing processing (step S 3 ). In the stitched marker sewing processing of the present embodiment, the CPU 61 generates stitched marker data that is data to sew the stitched marker 150 in a position where the stitched marker 150 will be covered by the embroidery pattern 200 . The CPU 61 controls the sewing mechanism 89 (refer to FIG. 3 ) to sew the stitched marker 150 in accordance with the generated stitched marker data. When the sewing position of the stitched marker 150 is set, the CPU 61 arranges a reference point of the stitched marker 150 at an inside position of the embroidery pattern 200 and determines whether the stitched marker 150 will be covered by the embroidery pattern 200 under the condition that the stitched marker 150 is formed according to the position of the reference point. The inside position of the embroidery pattern 200 is a position inside the embroidery pattern 200 including the contour of the embroidery pattern 200 . The reference point of the stitched marker 150 is a point that represents the sewing position of the stitched marker 150 . When the CPU 61 determines that the stitched marker 150 will be covered by the embroidery pattern 200 , the CPU 61 generates the stitched marker data to sew the stitched marker 150 whose reference point is arranged at the inside position. The CPU 61 preferentially reads out, from among the plurality of needle drop points represented by the embroidery data, the coordinates of the needle drop point that comes later in a sewing order, and sets the coordinates as the reference point of the stitched marker 150 . Hereinafter, the stitched marker sewing processing will be explained in detail with reference to FIG. 7 .
As shown in FIG. 7 , the CPU 61 sets a variable T to 0 (step S 41 ). The variable T is a variable used to count the number of the stitched markers 150 that have already been set. Next, the CPU 61 generates data of an embroidery pattern image based on the embroidery data acquired by the processing at step S 1 shown in FIG. 6 (step S 43 ). The embroidery pattern image is an image that represents the finished embroidery pattern 200 when the embroidery pattern 200 is sewn in accordance with the embroidery data. When the coordinate data of the embroidery data represents the X axis movement amount and the Y axis movement amount of the embroidery frame 53 , the CPU 61 identifies the coordinates of the needle drop point in the embroidery coordinate system for each data number, based on the coordinate data. When the coordinate data of the embroidery data represents the coordinates in the embroidery coordinate system, this processing is omitted. Next, the CPU 61 represents the stitches included in the embroidery pattern 200 as line segments connecting the needle drop points of the respective data numbers, to generate data of the embroidery pattern image. As a specific example, data that represents an embroidery pattern image 170 shown in FIG. 8 is generated based on the embroidery data of the embroidery pattern 200 .
Next, the CPU 61 sets a final needle drop point number L as a needle drop point number M (step S 45 ). The needle drop point number M is a variable used to preferentially read out, from among the plurality of needle drop points represented by the embroidery data, the coordinates of the needle drop point that comes later in the sewing order. The final needle drop point number L is a maximum value of the data numbers included in the embroidery data. Next, from among the coordinates of the needle drop points identified by the processing at step S 43 , the CPU 61 acquires coordinates of the needle drop point number M (the data number is M) (step S 47 ). Next, the CPU 61 temporarily sets the coordinates acquired at step S 47 as the coordinates of the reference point of the stitched marker 150 (step S 49 ). In the present embodiment, a center point 161 (refer to FIG. 4 ) of the stitched marker 150 is used as the reference point of the stitched marker 150 . As a result of the processing at step S 49 , the reference point of the stitched marker 150 is temporarily arranged at the inside position. Next, the CPU 61 generates data of a stitched marker image based on the unit data of the stitched marker 150 , the coordinates acquired at step S 47 and an extra length that is set in advance (step S 51 ). The stitched marker image is an image that represents the finished stitched marker 150 when the stitched marker 150 is sewn in a position where the reference point of the stitched marker 150 matches the coordinates acquired at step S 47 . The stitched marker image is used in processing that sets the sewing position of the stitched marker 150 to a position where the stitched marker 150 will be covered by the embroidery pattern 200 . The extra length is an excess length that is set in advance in order to set the sewing position of the stitched marker 150 to a position where the stitched marker 150 will completely be covered by the embroidery pattern 200 . The extra length of the present embodiment may be 1 mm. The CPU 61 sets the size of the stitched marker 150 in the X direction and the Y direction such that the size is increased by an amount corresponding to the extra length, and then generates data of the stitched marker image. As a specific example, data that represents a stitched marker image 180 shown in FIG. 9 is generated.
Next, the CPU 61 determines whether the stitched marker 150 will be covered by the embroidery pattern 200 when the stitched marker 150 is formed in the position temporarily set at step S 49 (step S 53 ). Based on the data generated at step S 43 and step S 51 , the CPU 61 overlaps the embroidery pattern image 170 and the stitched marker image 180 , and when the whole stitched marker 150 is overlapped with the embroidery pattern 200 , the CPU 61 determines that the stitched marker 150 will be covered by the embroidery pattern 200 . In the present embodiment, particularly, when the whole stitched marker 150 is overlapped only with stitches of the same thread color as the stitch of the needle drop point number M, it is determined that the stitched marker 150 will be covered by the embroidery pattern 200 . As shown by an image 190 in FIG. 10 , when the sewing position of the stitched marker 150 is indicated by a position 251 in FIG. 9 with respect to the sewing position of the embroidery pattern 200 , the whole stitched marker 150 overlaps only with stitches of the pattern 203 of the third color (yes at step S 53 ). Therefore, the CPU 61 increments the variable T by one (step S 55 ). Next, based on the unit data of the stitched marker 150 and the coordinates acquired at step S 47 , the CPU 61 generates the stitched marker data to sew the T-th stitched marker 150 in the position indicated by the position 251 (step S 57 ). The CPU 61 stores the needle drop point number M in the RAM 63 in association with the variable T. Through the processing at step S 57 , the data to sew the stitched marker 150 such that the reference point of the stitched marker 150 is arranged at a position inside the embroidery pattern 200 is generated as the stitched marker data.
Next, the CPU 61 controls the sewing mechanism 89 (refer to FIG. 3 ), to sew the stitched marker 150 based on the stitched marker data generated at step S 57 (step S 59 ). In the processing at step S 59 of the present embodiment, a task of replacing the thread spool 20 is taken into consideration, and the thread of the first color of the embroidery pattern 200 is used to sew the stitched marker 150 . The CPU 61 stores the color of the T-th stitched marker 150 in association with the variable T. Next, when the variable T is equal to or less than 2 (no at step S 61 ), the CPU 61 sets the needle drop point number M to a value obtained by subtracting a constant K from the needle drop point number M (step S 63 ). The constant K is a constant that is set in advance, considering setting the sewing position of each of the stitched markers 150 such that the plurality of stitched markers 150 do not overlap with each other. The constant K may be 50, for example.
In the processing at step S 53 , when the sewing position of the stitched marker 150 with respect to the sewing position of the embroidery pattern 200 is shown by a position 254 on the image 190 in FIG. 10 , the stitched marker 150 will be not covered by the embroidery pattern 200 (no at step S 53 ). When the sewing position of the stitched marker 150 with respect to the sewing position of the embroidery pattern 200 is shown by a position 255 on the image 190 in FIG. 10 , although the stitched marker 150 will be covered by the embroidery pattern 200 , the stitched marker 150 overlaps with the pattern 201 of the first color, as well as overlapping with the pattern 203 of the third color of thread (no at step S 53 ). In these cases, the CPU 61 decrements the needle drop point number M by one (step S 65 ). After the processing at step S 63 or the processing at step S 65 , if the needle drop point number M is equal to or more than 2 (no at step S 67 ), the processing returns to step S 47 . When the needle drop point number M is less than 2 (yes at step S 67 ), the CPU 61 controls the drive circuit 71 (refer to FIG. 3 ) and causes the LCD 15 to display an error message (step S 69 ). The error message is displayed to notify the user of the fact that three of the stitched markers 150 cannot be formed. After the processing at step S 69 , the stitched marker sewing processing ends and the processing returns to the main processing shown in FIG. 6 .
The processing at step S 53 is repeatedly performed, and if, with respect to the sewing position of the embroidery pattern 200 , the sewing position of the stitched marker 150 is sequentially set to three positions (i.e., the position 251 , a position 252 and a position 253 ) shown in FIG. 10 , it is determined that the variable T is more than 2 (yes at step S 61 ). In this case, the stitched marker sewing processing ends here and the processing returns to the main processing shown in FIG. 6 .
After the processing at step S 3 in FIG. 6 , the CPU 61 controls the sewing mechanism 89 (refer to FIG. 3 ) and causes the sewing of the embroidery pattern 200 to be started in accordance with the embroidery data acquired at step S 1 (step S 5 ). Next, the CPU 61 determines whether the sewing of the embroidery pattern 200 is stopped (step S 7 ). In the processing at step S 7 of the present embodiment, the CPU 61 determines that the sewing of the embroidery pattern 200 has been stopped in each of the following cases: when thread replacement is necessary; when the sewing workpiece 100 has been removed from the embroidery frame 53 ; and when the user performs the panel operation to command that the sewing of the embroidery pattern 200 be stopped. When the sewing has been stopped (yes at step S 7 ), the CPU 61 identifies a current needle drop point number N (step S 9 ). The current needle drop point number N is a maximum value of the data numbers corresponding to the sewn pattern.
Next, the CPU 61 determines whether the number of the stitched markers 150 that are not covered by the sewn pattern is two or more (step S 11 ). Based on the current needle drop point number N identified at step S 9 and on the needle drop point number M and the variable T stored at step S 57 in FIG. 7 , the CPU 61 sequentially determines whether the T-th stitched marker 150 is covered by the sewn pattern, and identifies the number of the stitched markers 150 that are not covered by the sewn pattern. The processing at step S 11 is processing to identify the number of the stitched markers 150 that can be detected based on a captured image. In the present embodiment, taking account of detection accuracy of the stitched marker 150 , the stitched marker 150 that is assumed not to overlap with the sewn pattern at all is taken as the stitched marker 150 that can be detected based on the captured image. Specifically, when a number obtained by adding a constant S to the current needle drop point number N is larger than the needle drop point number M that corresponds to the variable T, the CPU 61 determines that the T-th stitched marker 150 is covered by the sewn pattern. The constant S is a constant that is set in consideration of conditions that include the size of the stitched marker 150 , the position of the reference point with respect to the whole stitched marker 150 and the length of the stitches of the embroidery pattern 200 . The constant S may be 25, for example.
In the specific example, when the three stitched markers 150 are not covered by the sewn pattern (yes at step S 11 ), the CPU 61 generates data that represents a feature point image based on the stitched marker data generated by the processing at step S 57 in FIG. 7 (step S 13 ). The feature point image is an image that represents positions of the feature points in the embroidery coordinate system. In the processing at step S 13 , the CPU 61 sets, as the feature points, the reference points of the stitched markers 150 that are not covered by the sewn pattern identified by the processing at step S 11 . The feature point image of the specific example is shown as in an image 260 in FIG. 11 . The image 260 includes feature points 261 to 263 that correspond to the stitched markers 150 sewn in the positions 251 to 253 (refer to FIG. 10 ) based on the stitched marker data generated in the processing at step S 57 in FIG. 7 .
When the number of the stitched markers 150 that are not covered by the sewn pattern is smaller than 2 (no at step S 11 ), the CPU 61 cannot set the layout (the sewing position and the sewing angle) of the pattern to be sewn, based on the positions of the stitched markers 150 . To address this, the CPU 61 extracts feature points from a sewn pattern image, and generates data of the feature point image (step S 15 ). The sewn pattern image is an image that represents the finished sewn pattern when the sewn pattern is sewn in accordance with the embroidery data. In the processing at step S 15 , when there is the stitched marker 150 that is not covered by the sewn pattern, the CPU 61 sets the reference point of the stitched marker 150 as a part of the feature points. The processing that extracts feature points from the sewn pattern image is performed in the following manner, for example. First, the CPU 61 generates, for the sewn pattern, data that represents the sewn pattern image, in the same manner as the data generated by the processing at step S 43 , based on the embroidery data acquired at step S 1 and the current needle drop point number N identified at step S 9 . Next, based on the generated data, the CPU 61 performs image processing (known edge detection processing, for example) on the sewn pattern image, and extracts feature points (intersection points of line segments included in the image, for example). As an edge detection technique, a known method may be used, such as a method that performs first-order differentiation on the image and detects a position at which the gradient is maximum, or a method that performs second-order differentiation on the image and detects a zero crossing point. Through the processing at step S 15 , the CPU 61 generates the feature point image that represents a plurality of feature points.
Next, the CPU 61 stands by until a command to restart the sewing is input by the panel operation (no at step S 17 ). When the command to restart the sewing is input by the panel operation (yes at step S 17 ), the CPU 61 acquires image data output from the image sensor 90 (step S 19 ). When an image capturing range of the image sensor 90 is smaller than a sewing area that is set inside the embroidery frame 53 , there are cases in which the stitched marker 150 and the sewn pattern are not included in the captured image, depending on the position of the embroidery frame 53 with respect to the carriage 52 . In this type of case, the relative position of the embroidery frame 53 may be appropriately changed until the stitched marker 150 and the sewn pattern are detected from the image data that represents the captured image. In the present embodiment, in order to simplify the explanation, a case will be explained in which the stitched marker 150 and the sewn pattern are included in the captured image represented by the image data acquired at step S 19 . As a specific example, a case will be explained which image data that represents a captured image 265 in FIG. 12 is acquired. In the specific example, a sewn pattern 266 is the pattern for which sewing is stopped in the middle of sewing the pattern 202 (refer to FIG. 5 or FIG. 8 ) of the second color.
Next, the CPU 61 detects feature points based on the image data acquired by the processing at step S 19 (step S 21 ). Processing that detects the feature points from the image data may be performed, as appropriate, using a known method. For example, at step S 21 , the feature points are detected in accordance with the following procedure. First, the CPU 61 extracts, from the captured image, a color that is similar to the color of a detection target (at least one of the stitched marker 150 and the sewn pattern), and thereafter performs edge detection using a known method (the above-described method, for example) on the captured image. Next, the CPU 61 extracts feature points (intersection points of line segments included in the image, for example) from the detected edges. In the a specific example, the CPU 61 extracts feature points 271 to 278 shown on an image 270 of FIG. 13 , based on the image data that represents the captured image 265 in FIG. 12 . The feature points 271 to 278 indicate positions of the intersection points that are extracted based on the edges obtained by processing the image data.
Next, the CPU 61 uses pattern matching to compare the feature points of the captured image and the feature point image generated in the processing at step S 13 or step S 15 , and determines whether a pattern (a layout of a plurality of feature points) that matches feature points of the feature point image is included among the feature points of the captured image (step S 23 ). For example, when a pattern that matches the feature points 261 to 263 of the image 260 in FIG. 11 is included among the feature points 271 to 278 extracted from the captured image 265 (yes at step S 23 ), the CPU 61 corrects the embroidery data (step S 27 ). In the specific example, the feature points 271 to 273 respectively correspond to the feature points 261 to 263 . The CPU 61 identifies coordinates in the world coordinate system of the feature points 271 to 273 based on the image data acquired at step S 19 . A known method can be used, as appropriate, as a method for identifying the coordinates in the world coordinate system. For example, the coordinates in the world coordinate system may be identified using a method described in detail in Japanese Patent Application Publication No. JPA-2010-246885, relevant portions of which are herein incorporated by reference.
For example, the CPU 61 uses the feature point 261 as a reference for the sewing position, and sets the sewing position of the pattern to be sewn based on the coordinates of the feature point 261 and the feature point 271 . The CPU 61 sets the sewing angle of the pattern to be sewn based on, for example, an inclination of a line segment that connects the feature point 261 and the feature point 263 and an inclination of a line segment that connects the feature point 271 and the feature point 273 in the embroidery coordinate system. At this time, the position of the feature point 262 with respect to the line segment that connects the feature point 261 and the feature point 263 , and the position of the feature point 272 with respect to the line segment that connects the feature point 271 and the feature point 273 are taken into consideration. In the specific example, based on the layout of the three stitched markers 150 , the CPU 61 sets the sewing position and the sewing angle of a pattern 281 to be sewn with respect to the layout of the sewn pattern 266 , as shown by an image 280 in FIG. 14 , and corrects data that is included in the embroidery data and that is used to sew the pattern 281 to be sewn. Next, the CPU 61 controls the sewing mechanism 89 (refer to FIG. 3 ), and causes the sewing mechanism 89 to sew the pattern 281 to be sewn in accordance with the embroidery data corrected at step S 27 (S 29 ). Specifically, the CPU 61 causes the sewing mechanism 89 to form stitches that correspond to the needle drop point number (N+1) onward. The needle drop point number (N+1) is the number following the needle drop point number N identified at step S 9 .
When the pattern that matches the feature points of the feature point image is not included in the feature points of the captured image (no at step S 23 ), the CPU 61 controls the drive circuit 71 (refer to FIG. 3 ) and causes the LCD 15 to display an error message (step S 25 ). After that, the processing returns to step S 17 . The error message is displayed to notify the user of the fact that the layout of the pattern 281 to be sewn cannot be set based on the image data, and to prompt the user to redo the operation to cause the embroidery frame 53 to clamp the sewing workpiece 100 . The error message is, for example, “There is no corresponding image on the cloth. Please re-attach the cloth”.
When the sewing is not stopped in the processing at step S 7 (no at step S 7 ), or after processing at step S 29 , when the sewing of the embroidery pattern 200 is not complete (no at step S 31 ), the processing returns to step S 7 . When the sewing of the embroidery pattern 200 is complete (yes at step S 31 ), the main processing ends there.
With the sewing machine 1 of the present embodiment, when the position of the pattern 281 to be sewn is adjusted with respect to the sewn pattern 266 , it is possible to automatically set the layout of the pattern 281 to be sewn with respect to the sewn pattern 266 . Since the stitched markers 150 are covered by the embroidery pattern 200 , there is no need to remove the stitched markers 150 after the sewing. Since the stitched markers 150 are covered by the embroidery pattern 200 , the stitched markers 150 do not degrade the appearance of the embroidery pattern 200 . When the stitched markers 150 are detected, the sewing machine 1 can detect the position of each of the stitched markers 150 on the sewing workpiece 100 based on the image data generated by capturing an image of the stitches formed on the sewing workpiece 100 . The sewing machine 1 sews a plurality of the stitched markers 150 for the single embroidery pattern 200 . Therefore, the sewing machine 1 can accurately set the layout of the pattern 281 to be sewn, in comparison to a case in which the layout of the pattern 281 to be sewn is set based on a single stitched marker. For that reason, the sewing machine 1 can improve the appearance of the finished embroidery pattern, in comparison to the case in which the layout of the pattern 281 to be sewn is set based on a single stitched marker. In the present embodiment, the three stitched markers 150 are sewn for the single embroidery pattern 200 . It is therefore possible to set the sewing angle with even greater accuracy, in comparison to a case in which the number of the stitched markers 150 is two.
When the processing that detects the stitched markers 150 is performed, if the number of the stitched markers 150 that are not covered by the sewn pattern 266 is less than 2 (no at step S 11 ), feature points are extracted also from the sewn pattern image. Therefore, in comparison to a case in which the layout of the pattern 281 to be sewn is set based on a single feature point, the sewing machine 1 can accurately set the layout of the pattern 281 to be sewn and can thus improve the finished appearance of the embroidery pattern 200 . When the stitched marker 150 is not detected, the sewing machine 1 can set the layout of the pattern 281 to be sewn based on the layout of the sewn pattern 266 . Therefore, regardless of whether the stitched markers 150 are covered by the sewn pattern 266 at a point in time at which the sewing of the embroidery pattern 200 is stopped, it is possible to easily adjust the position of the pattern 281 to be sewn with respect to the sewn pattern 266 .
Through the processing at step S 43 , step S 45 , step S 47 , step S 49 , step S 51 , step S 53 , step S 57 , step S 63 and step S 65 in FIG. 7 , the sewing machine 1 can set the sewing position of the stitched marker 150 to a position where the stitched marker 150 will be covered by the embroidery pattern 200 , using a relatively simple procedure. The sewing machine 1 can preferentially form the stitched marker 150 that will be covered by stitches to be formed later in the sewing order. Thus, in comparison to a case in which the stitched marker 150 is covered by stitches that are fanned relatively early in the sewing order, it is possible to reduce the possibility that the stitched marker 150 is covered by the embroidery pattern 200 at a point in time at which the sewing of the embroidery pattern 200 is stopped. Therefore, the sewing machine 1 can reduce the possibility that the stitched marker 150 cannot be used for position adjustment of the pattern 281 to be sewn due to the fact that the stitched marker 150 is completely covered by the embroidery pattern 200 at the point in time at which the sewing of the embroidery pattern 200 is stopped. In the processing at step S 53 , the sewing machine 1 determines that the stitched marker 150 will be covered by the embroidery pattern 200 when the whole stitched marker 150 overlaps only with stitches of the same thread color as the stitch of the needle drop point number M. This is because it is considered that the feature points can be more easily extracted from the image that represents the stitched marker 150 when the stitched marker 150 does not overlap with the embroidery pattern 200 at all. Thus, in comparison to a case in which the position to form the stitched marker 150 is set without considering the stitches that overlap with the stitched marker 150 , the sewing machine 1 can reduce the possibility that the stitched marker 150 will overlap with the stitches of the embroidery pattern 200 at the point in time at which the sewing of the embroidery pattern 200 is stopped. For that reason, the sewing machine 1 can secure the accuracy of the processing that extracts feature points from the image that represents the stitched marker 150 .
The sewing machine according to the present disclosure is not limited to the embodiments described above, and various types of modifications may be made. For example, the modifications (A) to (E) described below may be made as desired.
(A) The structure of the sewing machine 1 may be changed as appropriate according to need. For example, the structure of the sewing machine 1 may be applied to an industrial-use sewing machine and to a multi-needle sewing machine. The sewing machine 1 may be configured such that the embroidery device 2 is not removable from the sewing machine 1 . The type and the layout of the image sensor 90 may be changed as appropriate. More specifically, the image sensor 90 may be an imaging element other than the CMOS image sensor, such as a CCD camera or the like. When image data is not used in the processing that detects the layout of the stitched markers 150 , the imaging element may be omitted.
(B) In the stitched marker sewing processing shown in FIG. 7 , the sewing machine 1 need not necessarily detect the layout of the stitched markers 150 based on the image data generated by the image sensor 90 . For example, the sewing machine 1 may detect the layout of the stitched markers 150 using an ultrasonic pen that generates an ultrasonic wave and a detector that detects the ultrasonic wave. In this case, the user may press a pen tip of the ultrasonic pen against the center point 161 of the stitched marker 150 on the sewing workpiece 100 . The sewing machine 1 may identify the coordinates in the world coordinate system of the stitched marker 150 by identifying the position of a transmission source of the ultrasonic wave.
(C) The color, the design, the shape, the size and the number of the stitched markers 150 can be changed as appropriate. For example, the stitched marker 150 may be sewn using a thread color other than the colors used to sew the embroidery pattern, such as a thread color that is determined taking into account a contrast with the sewing workpiece. When the stitched marker 150 indicates the sewing position, the shape of the stitched marker 150 may be a cross shape, a circle or a star shape, for example. The size of the stitched marker may be automatically changed, taking the size etc. of the embroidery pattern into account. The sewing machine 1 may sew at least one stitched marker with respect to one embroidery pattern. The stitched marker 150 may be used as a reference for at least one of the sewing position and the sewing angle of the embroidery pattern. For example, when arrow shaped stitches are used as a stitched marker, a single stitched marker may represent at least one of the sewing position and the sewing angle. In this case, for example, the direction indicated by the arrow may represent the angle of the embroidery pattern with respect to the reference, and the tip end of the arrow may represent the position of the reference point (the center point, for example) of the embroidery pattern with respect to the sewing workpiece. It is sufficient if the reference point of the stitched marker is a point that represents the sewing position of the stitched marker. The reference point of the stitched marker is not limited to a point on the stitched marker, such as the center point 161 of the stitched marker 150 , and may be a point that is not on the stitched marker, such as a vertex of a rectangle in which the stitched marker 150 is inscribed.
(D) It is sufficient that the program that includes an instruction to execute the main processing is stored in a storage device included in the sewing machine 1 before the sewing machine 1 executes the program. The acquiring method and the acquiring route of the program, and the device that stores the program may each be changed as appropriate. Therefore, the program executed by the CPU 61 may be received from another device via a communication cable or wireless communication and may be stored in a storage device, such as the flash ROM 64 . Examples of the other device include a personal computer (PC) and a server that is connected via a network. In a similar manner, it is sufficient that data, such as the embroidery data, is stored in a storage device included in the sewing machine 1 until the sewing machine 1 executes the program. The acquiring method and the acquiring route of the embroidery data and the device that stores the embroidery data may each be changed as appropriate. The data, such as the embroidery data, may be received from another device via a communication cable or wireless communication, and may be stored in a storage device, such as the flash ROM 64 .
(E) Each of the steps of the main processing shown in FIG. 6 and FIG. 7 is not limited to the example performed by the CPU 61 , and some or all of the steps may be performed by another electronic device (an application-specific integrated circuit (ASIC), for example). Each of the steps of the main processing may be performed in a distributed manner by a plurality of electronic devices (a plurality of CPUs, for example). Each of the steps of the main processing may be performed in a different order or may be omitted, or another step may be added, if necessary. For example, the following modifications (E-1) to (E-3) may be made.
(E-1) In the processing at step S 11 shown in FIG. 6 , at a point in time at which the sewing of the embroidery pattern is stopped, the data of the feature point image to be generated by the CPU 61 need not necessarily be different depending on whether the number of the stitched markers that are not covered by the sewn pattern is two or more, and may be the same. More specifically, regardless of whether each of the stitched markers is covered by the embroidery pattern, the sewing machine 1 may generate a feature point image that represents feature points representing sewing positions of the stitched markers. In this case, when the generated feature point image does not match the feature points extracted from the captured image, the sewing machine 1 may extract feature points from the sewn pattern image or from the embroidery pattern image. Even when the sewing of the embroidery pattern is stopped (yes at step S 7 ), if there is no need to reset the layout of the pattern to be sewn, the processing that sews the pattern to be sewn may be performed in accordance with the embroidery data. Based on the sewing position of at least one of the stitched marker and the sewn pattern, the sewing position of the pattern to be sewn may be set in accordance with the sewing position of the sewn pattern on the sewing workpiece. Based on the sewing angle of at least one of the stitched marker and the sewn pattern, the sewing angle of the pattern to be sewn may be set in accordance with the sewing angle of the sewn pattern on the sewing workpiece. Even in these cases, the sewing machine 1 can save the user the trouble of setting one of the sewing position and the sewing angle of the pattern to be sewn in accordance with the layout of the sewn pattern on the sewing workpiece.
(E-2) In the stitched marker sewing processing shown in FIG. 7 , the coordinates of the needle drop points of the stitches of the embroidery pattern represented by the embroidery data need not necessarily be read out in the reverse order of sewing and set as the reference points of the stitched markers. The sewing machine 1 may read out the coordinates of the needle drop points of the stitches of the embroidery pattern represented by the embroidery data in the order of sewing, and may set the read-out coordinates as the reference points of the stitched markers. The sewing machine 1 may randomly read out the coordinates of the needle drop points of the stitches of the embroidery pattern represented by the embroidery data, and may set the read-out coordinates as the reference points of the stitched markers. The coordinates inside the embroidery pattern may be read out, in a predetermined order, as coordinates to be set as the reference points of the stitched markers. In this case, the predetermined order may be an order from the upper left to the lower right of the embroidery pattern image, for example.
(E-3) When the stitched marker is covered by the sewn pattern, the sewing machine 1 need not necessarily extract feature points from the sewn pattern and detect the layout of the sewn pattern with respect to the sewing workpiece. When the layout of the stitched marker cannot be detected as a result of, for example, the stitched marker being covered by the sewn pattern, the sewing machine 1 need not necessarily perform the processing that sets at least one of the sewing position and the sewing angle of the pattern to be sewn with respect to the sewn pattern.
The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles.
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A sewing machine includes a sewing device, a processor, and a memory. The sewing device is configured to form stitches on a sewing workpiece. The memory is to store computer-readable instructions that, when executed by the processor, instruct the processor to perform processes including acquiring embroidery data, generating stitched marker data, causing the sewing device to sew the at least one stitched marker, causing the sewing device to start sewing an embroidery pattern, identifying a pattern to be sewn when the sewing of the embroidery pattern is stopped, detecting at least one of a second sewing position and a second sewing angle when the sewing of the embroidery pattern is stopped, setting at least one of a third sewing position and a third sewing angle, correcting data to be used to sew the pattern to be sewn, and causing the sewing device to restart sewing the embroidery pattern.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to German Patent Application No. DE 10 2012 212 832.8, filed Jul. 23, 2012, which is hereby incorporated by reference herein in its entirety.
BACKGROUND
The present technology relates to an assembly for a line conduit to be molded in a part, particularly made from concrete, comprising a positioning module to fasten the assembly at a wall or a casting, a fire protection module, which comprises an intumescent fire protection element, and an oblong casting sheath, which jointly form a passage for a line.
Line conduits are used in the production of construction parts, made from concrete or another liquid building material, in order to provide clear wall or ceiling passages for lines, for example, wires or pipelines, or to integrate them here. The line conduits are positioned in a mold, into which the liquid building material is filled, and they keep a clearance in the wall or the ceiling when the building material is filled in.
The line conduits may be removed after the building material has cured. Frequently, however, they are left in the wall and additional elements, for example, seals or fire prevention elements, are arranged therein, which in case of a fire can close the passage in the wall or the ceiling. The fire protection element may comprise an intumescent material, which increases its volume under the influence of heat and this way closes the wall passage.
An assembly of such a line conduit should be flexible in its use, so that on site a quick adjustment to the various thicknesses of the component is possible and/or the fire prevention element can be positioned arbitrarily within the passage. On the other hand, the assembly must be easily handled, ideally assembled without the use of tools.
BRIEF SUMMARY
Certain aspects of the present technology relate to an assembly for a line conduit which allows a quick and flexible adjustment of the assembly to the desired installment conditions, but can easily be handled.
According to at least some embodiments of the present technology, an assembly is provided for the line conduit to be molded in a construction part, particularly made from concrete. The assembly includes a positioning module for fastening the assembly at a wall or a casting, a fire protection module with an intumescent fire protection element, and an oblong casting sheath, which jointly form a passage for a line. Accepts may be provided at the fire protection module for a reversible fastening of the casting sheath and/or the positioning module.
In prior art, either different prefabricated line conduits are provided for different applications or the fire protection module is produced separately from the sheath, which defines a passage, and subsequently assembled therein. The assembly according to the present technology offers the advantage that the assembly can be easily assembled on site because no additional connection elements are required. By exchanging the casting sheath or the positioning module, a simple adjustment to the installation conditions is possible. By a suitable positioning module, for example, an adjustment to arbitrary underground conditions is possible, while by an appropriate length of the casting sheath, an adjustment is possible to the desired thickness of the construction part.
For example, the fire protection module can be embodied annularly or cylindrically, so that it can entirely encompass a line in the circumferential direction and the passage can quickly and reliably be closed in case of a fire. The accepts are preferably provided at the axial faces of such an embodiment, so that the positioning module and the casting sheath can easily be assembled in the longitudinal direction at the fire protection module and here a cylindrical passage is formed by the three elements.
An anchoring element may be provided at the fire protection module. The anchoring element may comprising metal and may extend e.g., radially outwardly, from the fire protection element. The anchoring element may be embodied such that it also extends into the expanded fire protection element. Thus, via the anchoring element, the fire protection module is stabilized in the assembly and/or in the passage such that, after activation and expansion, it is held reliably in its position in the passage and the passage can be sealed, even under great stress, for example, by a fire fighting—water jet impinging the fire protection element.
This anchoring element may be embodied annularly, for example, and extend in the circumferential direction around the fire protection module so that it is circumferentially anchored in the component and cannot be displaced.
In order to achieve additional sealing of the passage, independent from the fire protection module, a sealing membrane may be provided at the inside of the assembly. In some embodiments the sealing element may be provided at the fire protection module and may be made, for example, from ethylene propylene diene rubber (EPDM). The sealing membrane may be constructed to seal the passage against moisture, dust, or noise for example.
The assembly may additionally comprise a reinforcement sheath, which covers the fire protection module in the circumferential direction and/or at least partially at the faces. This reinforcement sheath serves, on the one hand, to protect the fire protection module during the production of the component so that the fire protection module cannot be damaged by the liquid building material. On the other hand, the fire protection module serves for stabilization in order to reinforce the accepts at the fire protection module for the positioning module and the casting sheath so that the assembly is embodied in a more stable fashion. The reinforcement sheath may, for example, be connected to the fire protection module and/or adhered thereto. The fire protection module may, for example, be injection molded in the reinforcement sheath and thus be connected with said part in a material-to-material connection.
In order to allow a simple plug-in connection of the modules of the assembly, the accepts may be formed, for example, by annular slots at the faces of the fire protection modules so that the positioning module as well as the casting sheath can easily be inserted into the fire protection module.
The casting sheath and/or the positioning module may be embodied cylindrical. In particular, they may be embodied adjustable with regard to their length so that a simple and quick adjustment of the assembly to the desired installation conditions is possible, for example, the position of the fire protection module in the component or the thickness of the part.
At the end opposite the fire protection module, the casting sheath and the positioning module may be closed via an end cap so that, during the production of the part, any penetration of the liquid building material into the passage is prevented.
At the face away from the fire protection module a radially projecting assembly flange may be provided at the positioning module by which the assembly can be fastened and/or fixed at a mold to cast the part, for example, a concrete casting.
In some embodiments, this flange may comprise positioning elements, which allow a precise fixation and/or adjustment of the assembly to the mold. They may represent particularly adjusted devices in order to fasten the assembly on an uneven underground, for example, a troughed sheet, or on castings for prefabricated concrete parts. For example, in some embodiments at least some of the positioning elements may comprise a magnet which can adhere to an element that can be magnetized.
In some embodiments, the casting sheath and/or the positioning module may be made from plastic or cardboard, which allows a simple and cost-effective production.
In some embodiments of the assembly, the positioning module may be a cylindrical solid body. In order to allow a simple plug-in connection of the positioning module and the fire protection module, the positioning module may be provided with a brim and/or a flange. Here, the primary body of the positioning module is dimensioned such that it can be inserted into the passage opening formed by the fire protection module, and the fire protection module contacts the brim and/or the flange. The diameter of the solid body is beneficially selected such that it completely fills and particularly seals the passage opening formed by the fire protection module and perhaps also the casting sheath. This prevents any excessively deep insertion of the positioning module during the composition of the assembly and/or any displacement of the positioning module in the direction of the fire protection module during the generation of the component and thus ensures the position of the fire protection module inside the passage opening.
By the thickness of the brim and/or the flange, the insertion thickness of the fire protection module in the component to be produced can be selected such that an easy and quick adjustment of the assembly to the desired installation conditions is possible.
In this embodiment, the positioning module may be a beneficial plastic, such as polystyrene.
In some embodiments, the positioning module may, alternatively, be formed like a plate, upon which the fire protection module can simply be placed. In order to fixate the position of the fire protection module, the plate may be provided with a cylindrical projection with the fire protection module being plugged thereon and thus its position being fixed.
In the two most recently mentioned embodiments, the positioning module may be fixated, for example, via fastening elements, such as nails, to the casting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded illustration of an assembly according to certain embodiments of the present technology.
FIGS. 2 a and 2 b are various production steps to produce a component with the assembly according to certain embodiments of the present technology.
FIG. 3 is a component with an assembly according to certain embodiments of the present technology.
FIG. 4 is a detail of the fire protection module of the assembly of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows schematically an assembly 10 for a line conduit in a component 12 (also see FIG. 3 ). The component 12 is produced from a liquid material 48 , which is inserted into a mold 26 (see FIGS. 2 a and 2 b ) and cures therein. During the production of the component 12 , the assembly 10 preserves a passage 14 through which, after the component 12 has been produced, lines can be guided, for example, pipelines or wires. Additionally, this assembly 10 can seal the passage 14 and this way, for example, in case of a fire, prevent the penetration of smoke, fire, or moisture.
The assembly 10 comprises a positioning module 16 , as shown in the following, which serves for the positioning and/or fixation of the assembly 10 during the production of the component 12 as well as a casting sheath 18 and a fire protection module 20 .
The positioning module 16 is essentially embodied cylindrical and comprises an assembly flange 24 at its end 22 , facing away from the fire protection module 20 . The assembly flange 24 can be fastened and/or fixated on or in the mold 26 in order to determine the position of the passage 14 .
The casting sheath 18 is also embodied cylindrical and may be embodied in a longitudinally adjustable fashion, similar to the positioning module 16 . The casting sheath 18 and the positioning module 16 may be closed at their end facing away from the fire protection module 20 , by respective removable end cap 28 , 30 . The end caps 28 , 30 can be removed after the production of the component 12 so that the passage 14 is freely accessible.
As is particularly discernible in FIG. 4 , the fire protection module 20 comprises a fire protection element 32 made from an intumescent material as well as a reinforcement sheath 34 , which is embodied with a U-shaped cross-section and covers the fire protection element 32 in the circumferential direction and partially at the faces. The fire protection element 32 is connected to a reinforcement sheath 34 in a material-to-material connection, for example, by way of adhesion or by injecting material of the fire protection element 32 into the reinforcement sheath 34 .
When the intumescent material of the fire protection element 32 is heated, the intumescent material expands. Due to the fact that the fire protection module 20 is arranged in the passage 14 , the fire protection element 32 seals the passage 14 by way of foaming so that any penetration by fire or smoke is prevented.
Accepts 44 , 46 , formed by annular slots 40 , 42 , are each provided at the faces 36 , 38 of the fire protection module 20 into which the positioning module 16 and/or the casting sheath 18 can be inserted in the longitudinal direction L.
In order to produce a component 12 the positioning module 16 is inserted into the first accept 44 and the oblong casting sheath 18 into the second accept 46 ( FIG. 2 a ) and the end caps 28 , 30 are placed thereon. This way, a closed passage 14 is formed into which no liquid material can flow.
Subsequently, this component 10 is fixated at the mold 26 by the assembly flange 24 of the positioning module 16 being fastened on the mold 26 . This may occur, for example, by additional fastening elements, for example, using screws or nails, which project through bore holes at the assembly flange 24 into the mold 26 .
Alternatively, cooperating positioning elements may be provided at the assembly flange 24 and at the mold 26 . For example, a magnetic element may be provided at the assembly flange 24 . The mold 26 may be produced at least partially from a material that can be magnetized or comprises positioning elements that can be magnetized, so that magnetic elements of the assembly 10 adhere magnetically to the mold 26 . The magnet may also be provided at the mold 26 so that the flange 24 and/or the positioning module 16 show no magnetic features after the installation. The positioning module 16 and/or the assembly flange 24 may also be fastened prior to the composition of the assembly 10 at the mold 26 .
After the alignment and fixation of the assembly 10 at the mold 26 , the mold 26 is filled with a liquid building material 48 ( FIG. 2 b ), for example concrete, which cures after being inserted. After the building material 48 has cured, the mold 26 is removed, with in the exemplary embodiment shown the positioning module 16 together with the mold 26 and the end cap 28 being removed ( FIG. 3 ). It is also possible that the positioning module 16 remains in the component 12 and only the end cap 28 is removed.
Subsequently, the end cap 30 of the casting sheath 18 is removed so that the passage 14 is freely accessible and a line can be guided through the passage 14 .
Due to the fact that this assembly 10 is designed in a modular fashion, a quick and simple adjustment is possible to the desired installation conditions. By an appropriate selection of the casting sheath 18 , an adjustment of the assembly 10 to the desired thickness of the component 12 is possible. Additionally, by exchanging the positioning module 16 , the position of the fire protection module 20 can be varied in the component 12 . It is also possible that a longitudinally adjustable casting sheath 18 and/or a longitudinally adjustable positioning module 16 are used.
Depending on the desired sealing requirements for the assembly 10 and/or the line conduit, for example, the fire protection module 20 can be selected accordingly, or additional sealing measures can be installed.
FIG. 4 shows a second embodiment of a fire protection module 20 , as an example. The design of this fire protection module 20 is essentially equivalent to the previously shown exemplary embodiment. The fire protection module 20 additionally comprises an annularly formed anchoring element 50 , which extends in the radial direction into the fire protection element 32 , as well as a sealing membrane 52 , which extends into the passage 14 .
The anchoring element 50 is embodied such that it extends both in the non-expanded state as well as in the expanded state of the fire protection element 32 into it and is anchored therein. If applicable, the anchoring element may be deformed jointly with the fire protection element in the passage 14 . By the anchoring element 50 the fire protection element 32 is particularly stabilized in the expanded state in the passage 14 such that it can also withstand major stress, for example, a water jet impinging the fire protection element 32 , and a reliable sealing of the passage 14 is ensured.
The sealing membrane 52 may prevent the penetration of dust, liquids, etc. independent from the function of fire protection. The sealing membrane 52 may be produced, for example, from an ethylene propylene diene rubber (EPDM), which ensures a permanent water seal of the membrane.
In an alternative embodiment of the assembly flange 24 , the positioning module 16 may be constructed from a foam block, which is arranged inside the passage 14 . Such a foam block can simply be placed upon the mold 26 . Subsequently, the assembly 10 can be placed upon this foam block and fixated thereon. The foam block additionally fulfills the function of the end cap so that an additional part can be waived, here.
While particular elements, embodiments, and applications of the present invention have been shown and described, it is understood that the invention is not limited thereto because modifications may be made by those skilled in the art, particularly in light of the foregoing teaching. It is therefore contemplated by the appended claims to cover such modifications and incorporate those features which come within the spirit and scope of the invention.
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An assembly for a line conduit is configured to be molded into a construction part, such as a concrete casting. The assembly includes positioning module configured for fastening the assembly to a structure, such as a wall or casting. The assembly also includes a casting sheath and a fire protection module, which includes an intumescent fire protection element. The positioning module, the fire protection module and the casting sheath cooperate to form a line passage. The fire protection module includes accepts for a reversible fastening of the casting sheath and/or the positioning module.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process and to a device for measuring the velocity and the flow rate of a fluid stream.
2. Description of the Prior Art
Accurate determination of the circulation rate of fluids in pipes and of the corresponding flow rates is important in many fields, notably in chemical plants, chromatography, etc.
A known process for determining the velocity and the flow rate of a fluid stream circulating in a pipe is for example described in WO-93/14,382 or U.S. Pat. No. 4,308,754. It essentially consists in measuring the difference between the respective traveltimes of acoustic pulses between emitting and receiving transducers situated along a fluid feeder, at a known distance from one another, according to whether the waves are propagated upstream or downstream in relation to the direction of flow.
The flowsheet of FIG. 1 shows two piezoelectric type emitting-receiving transducers for example, arranged on either side of a pipe in which a fluid circulates at a velocity v, in two transverse planes thereof at a distance from one another. They simultaneously emit, one in the direction of the other (slantwise), ultrasonic pulses of frequency f 0 (transducers tuning frequency) and of duration t 0 much shorter than the traveltime of the waves between the two transducers. The arrival times t AB and t BA of the signals are measured and the acoustic transit times (or traveltimes) tv 1 (in the direction of flow) and tv 2 (in the opposite direction) are deduced by subtracting therefrom the different parasitic lag times obtained by calibration.
Propagation times tv 1 and tv 2 are respectively written as follows: tv 1 = L C + V cos α and tv 2 = L C - V cos α
It is readily deduced therefrom that: V = L · Δ t 2 · tv 1 · tv 2 · cos α
where Δt=tv 2 −tv 1 .
The flow rate is then expressed by Qv=v.S, if S represents the cross-section of the stream.
In a practical example where the transducers are about 10 cm apart and the celerity of the waves in the fluid is 1500 m/s, the traveltime is about 60 μs. It can be noticed, with such a practical example, that if the desired accuracy is of the order of 10 −3 when measuring the velocity of flow, it must be possible to measure time intervals of the order of a few ns. This is very difficult to achieve by direct measurement of the propagation times with detection of the times when the energy received exceeds a certain threshold, because the accuracy is generally insufficient and implies working out many averages.
The process according to the invention notably overcomes this drawback and obtains, at a comparatively much lower cost than with the previous solution, a very high accuracy when measuring the displacement velocity of a fluid stream and consequently the flow rate of this stream.
SUMMARY OF THE INVENTION
The process of the invention allows determination of the velocity of flow of a fluid stream by comparison of the respective traveltimes of acoustic pulses respectively emitted and received between points spaced out along the fluid stream, according to whether they are propagated upstream or downstream in relation to the direction of flow. It is characterized in that the average traveltime and the difference between the traveltimes are measured by determination of the frequency spectrum associated with each pulse received and precise measurement of the relative phase lags affecting the frequency spectra of the acoustic pulses received, resulting from their traveltime.
According to an advantageous embodiment (suitable for relatively less absorbent fluids), a first acoustic pulse is emitted at each point, a second acoustic pulse is emitted from another point and an echo, at this other point, of the first acoustic pulse are successively detected at each point, the frequency spectra of the various pulses detected are calculated, and the average traveltime of the acoustic pulses detected and the differences between their respective traveltimes are determined.
According to another embodiment, the average traveltime is determined from reference spectra obtained by calibration from spectra of received acoustic pulses.
According to another embodiment, the difference between the respective traveltimes of the acoustic pulses received is determined from their frequency spectra and from a time difference obtained by calibration.
According to a preferred embodiment, the process comprises transmitting acoustic pulses simultaneously from a first point along a fluid stream in the direction of a second point downstream from the first point and vice versa from the second point in the direction of the first point, and detecting the pulses received at both points in fixed reception windows subjected to the same time lag in relation to the common times of emission of these pulses, the phase lag measured for each frequency spectrum depending on the position of the corresponding pulse received in the corresponding reception window.
To remove any ambiguity about the phase lag value, the slope of the line representative of the phase variation as a function of the traveltime is preferably determined on a determined portion of the frequency spectrum of the pulses.
A device allowing implementation of the method comprises for example at least two emitting-receiving transducers arranged in distinct places along a fluid stream, an impulse generator connected to the transducers, a signal acquisition unit samples and digitizes the signals received by the transducers during a fixed acquisition window and a processing unit for determining the phase lags affecting at least a portion of the frequency spectrum of each pulse received, due to the variable traveltime of the acoustic pulses emitted.
The processing unit comprises for example a signal processor programmed to determine the FFT frequency spectrum of each signal from a series of samples acquired in said window.
The process according to the invention provides very high accuracy for measurement of the traveltime of waves through the fluid in motion. It allows very short time intervals difficult to measure with accuracy under acceptable economic conditions to be translated into large phase variations with great amplification. Simulations showed that accuracies higher than 1‰ can be obtained for velocity measurement.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the process and of the device according to the invention will be clear from reading the description hereafter of a non limitative realization example, with reference to the accompanying drawings wherein.
FIG. 1 is a diagram illustrating the measuring principle,
FIG. 2 shows an example of variation of the amplitude A of a received acoustic pulse as a function of time,
FIG. 3 shows an example of variation of the complex amplitude G(k) of the frequency spectrum of a received pulse as a function of the sampling index k,
FIGS. 4 a and 4 b respectively show the variation of the amplitude G(k) of the frequency spectrum in the vicinity of a spectral maximum I M and the corresponding phase variation,
FIGS. 5 a and 5 b respectively show the variation of the amplitude G(k) of the frequency spectrum in the vicinity of a spectral maximum I M and the relative phase difference obtained after restoration of the variation continuity,
FIG. 6 shows the monotonic variation of the relative phase on 9 samples around the sampling index corresponding to a spectral maximum,
FIG. 7 illustrates the principle for calculating a calibration coefficient,
FIG. 8 illustrates the principle of the measuring method associating measurement of the direct arrivals of the pulses after propagation and measurement of the arrivals of their echoes in return, and
FIG. 9 shows a mode of layout of the device for implementing the process, with two acoustic pulse emitting-receiving transducers spaced out along a fluid stream.
DETAILED DESCRIPTION OF THE INVENTION
The process can be implemented for example by placing at two points A, B (FIG. 1) two ultrasonic wave emitting-receiving transducers P A , P B respectively in two distinct cross-sections of a pipe in which a fluid stream circulates at a velocity V, so arranged that each one can receive the waves emitted from the other transducer. The tranducers simultaneously emit, one in the direction of the other (slantwise for example), ultrasonic pulses of frequency f 0 (transducers tuning frequency) and of duration t 0 much shorter than the acoustic transit time (or traveltime) tv of the waves between the two transducers. The arrival times t AB and t BA of the signal are measured (FIG. 2 ), and traveltimes tv 1 (in the direction of flow) and tv 2 (in the opposite direction) are deduced by subtracting therefrom the different parasitic lag times obtained by calibration.
The propagation times are respectively written as follows: tv 1 = L C + V cos α and tv 2 = L C - V cos α
It can be readily deduced therefrom that: V ≅ Δ t · L 2 · tv 1 · tv 2 · cos α
where Δt=tv 2 −tv 1 .
Measurement of tv 1 and tv2 must be very accurate. In particular, the value of Δt=(tv 1 -tv 2 ) must be known with a higher accuracy than that desired for the device. The measured times include the response times of the piezoelectric elements on emission and reception for translating the electric signals into waves and vice versa. These response times are not known a priori and they can be different from one device to the other because of manufacturing variations. On the other hand, they can be considered to be substantially constant in time. The method comprises accurate measurement of time intervals by measuring the phase lags existing between the signals, due to their propagation, whose principle, known in the art, is described hereafter.
Consider two signals S 1 , S 2 emitted simultaneously from two transducers such as A, B during an emission window that is of course shorter than their traveltimes. They are respectively received at the opposite transducers in a single acquisition window opened at the same time t 0 and sampled with sampling frequency F e , N samples (N is for example equal to 2048) of each of these three signals are acquired. Their complex frequency spectra G 1 (k), G 2 (k) are determined by FFT, k being a sampling index ranging from 0 to N−1 (N=number of points of the FFT).
If G 1 (f) and G 2 (f) are the Fourier transforms of the two signals, the corresponding discrete transforms are obtained by replacing f by the sequence of integers k with the correspondance: f k = kF e N
Fe being the sampling frequency. ( F e N = frequency interval or Δ f ) .
These complex functions of k can be represented either by G(k)=ρ(k)(cos θ(k)+j sin θ(k)), or by G(k)=ρ(k)e jθ(k) (ρ=amplitude, θ=phase).
By application of the delay theorem, the Fourier transform of S 2 is: G 2 (f)=aG 1 (f)e −2πif(t2−t1) , (a representing the wave attenuation between the two receivers).
In the case of a discrete transform, if f is replaced by the sequence k such that: f k = kF e N ,
it is obtained: G 2 ( k ) = aG 1 ( k ) - 2 π i kF e N ( t 2 - t 1 ) ( 2 )
If G 2 (k) and G 1 (k) are now represented by ρ 2 (k)e jθ2(k) and ρ 1 (k)e jθ1(k) , equation (2) is written as follows: ρ 2 ( k ) j θ 2 ( k ) = a ρ 1 ( k ) j ( θ 1 ( k ) - 2 π j kF e N ( t 2 - t 1 ) ) ( 3 )
an equation that can also be written by means of the Napierian logarithm: ln ( ρ 2 ( k ) ) + j θ 2 ( k ) = ln ( a ρ 1 ( k ) ) + j ( θ ( k ) - 2 π kF e N ( t 2 - t 1 ) )
which directly gives: Δ t = ( t 2 - t 1 ) = - N 2 π kF e ( θ 2 ( k ) - θ 1 ( k ) ) ( 4 )
The function known as function of theoretical difference between the phases θ Δ (k)=θ 2 (k)−θ 1 (k) is a line passing through the origin for k=0 since Δt=(t 2 −t 1 ) is independent of k when remaining around a rather narrow portion (of ±150 kHz for example) of the spectrum centered around the emission frequency. The absolute value of the phase does not exceed π radians and the amplitude decreases rather fast on either side of the maximum with a correlative phase noise increase. The ambiguity about the value of the phase therefore has to be removed.
Method for Removing the Ambiguity About the Phase Difference
The maximum of the amplitude is determined on spectrum G 1 for example (FIG. 3 ), which gives an index k(Im).±4 points are (for example) taken around Im on the 2 spectra G 1 and G 2 , and the monotonicity of the phase variation is restored on these 9 points. This operation consists in replacing all the phase jumps of absolute value greater than π by their 2π complement (FIG. 5 b ). The phase values obtained for A and B are then subtracted point by point.
The relative phase difference is obtained (because it is known only to within 2nπ), i.e. θr Δ (k)=θ 1 (k)-θ 2 (k), whose variation curve is only close to a straight line, unlike the theoretical phase difference curve (FIG. 6 ).
By definition, the estimated phase is a straight line: θe Δ (k)=σ×k. Several methods can be used to determine the slope a of this line: calculation of a regression line going through the least squares at the points selected, calculation of the average of the slopes measured between two consecutive points, etc.
The difference between the estimated phase θe Δ (k) and the relative phase difference θr Δ (k) should thus be 2nπ (n integer representing a calibration coefficient) as illustrated by FIG. 7 . To calculate τ, it is sufficient to have the phase at one point, for example the point corresponding to the maximum of the amplitude of the spectrum, i.e., Im.
The measuring results show that the accuracy of the relative phase difference, i.e. θr Δ (Im), is higher than that of the estimated phase difference, i.e. θe Δ (Im)=σ×Im. The absolute (or restored) phase difference is selected to be:
θ Δ (Im)=θr Δ (Im)+2nπ (5)
with n = E * ( θ e Δ ( Im ) - θ r Δ ( Im ) 2 π + 0.5 )
( E * representing the whole part ) . ( 6 )
It can be noted that, for this restoration to be achieved without errors, it is necessary and sufficient that:
|θe Δ (Im)−θr Δ (Im)−2nπ|<π (7)
The time τ is thus obtained with the formula: τ = θ Δ ( Im ) N 2 π ImFe . ( 8 )
Echo Method
This method uses the signal corresponding to the echo of the signal emitted by each transducer, that returns after reflection on the opposite target transducer (FIG. 8 ). It has been experimentally verified that, for less absorbent fluids such as water or liquefied gases such as LPG, the piezoelectric transducers switched to reception receive not only the signal from the opposite element, but also the echo of their own emission reflected on the surface of the opposite element.
The time intervals measured between the primary signals and the echo signals then no longer depend on the emission delays (common to the two signals), and the following procedure can be carried out.
Two measurement windows W 1 , W 2 starting at times Tf 1 and Tf 2 are defined in relation to the time of emission of each wavetrain, so as to limit the number of points of the FFT and to have a good calibration coefficient n (meeting the criterion of equation (7)).
The times T ABe and T BAe , which are the time lags between the signals of equal form from receivers A and B, are measured by recording the direct signals in window W 1 , i.e. S A and S B , and the echo signals in window W 2 , i.e. Se A and Se B (for the same emission), and the four FFT complex spectra, i.e. G A (k), G B (k), Ge A (k) and Ge B (k), are calculated by FFT.
Determination of the Average Traveltime t vm
The procedure defined above is applied twice:
between Ge A (k) and G B (k), which gives a time τ AB =T ABe , i.e. difference (W 1 −W 2 )
between Ge B (k) and G A (k), which gives a time τ BA =T BAe , i.e. difference (W 2 −W 1 ) and finally T ABe =τ BA +(Tf 2 −Tf 1 ) and T BAe =τ AB +(Tf 2 −Tf 1 ).
If r E−A and r E−B respectively denote the delayed translation of the electric excitation signals of transducers A and B on emission into acoustic waves and if r R−A and r R−B denote the corresponding delays on reception by transducers A and B, the measured times t AB and t BA can be respectively expressed by:
T ABe =tv 1 +r R — B −r R — A
T BAe =tv 2 +r R — A −r R — B .
It can be seen that, by doing the half-sum, the parasitic delays cancel each other out and that the average traveltime t vm is expressed by: T ABe + T BAe 2 = tv 1 + tv 2 = t vm ( 8 )
Determination of Δt
The values τ BA and τ AB allow determination of Δt to within a constant error:
T BAe −T ABe =tv 2 +r R — A −r R — B −(tv 1 +r R — B −r R — A )=Δt+2r R — A .
Hence: Δt=T BAe −T ABe −τ 0 =τ AB −τ BA −τ 0
τ 0 can be obtained by calibration since it is known from equation (1) that Δt=0 if the velocity of the fluid is zero.
(τ 0 =τ AB −τ BA for V=0).
According to another embodiment, the time difference between signals S A and S B can also be measured directly by means of an aforementioned phase lag measurement between G B (k) and G A (k), which gives the time τ=t BA −t AB :
t BA −t AB =tv 2 −tv 1 +r E — B +r R — A −r E — A −r R — B , i.e,
Δt=τ−(r E — B +r R — A −r E — A −r R B )=τ−τ p0
the value τ p0 being obtained by calibration as above: τ p0 =τ at V=0.
The previous two modes can also be combined and the average of the Δt obtained is calculated in these two ways in order to increase the measuring accuracy.
Restored Reference Signal Method
It is possible that measurement of the velocity of very absorbent fluids (emulsions, muds, etc.) does not allow obtaining echoes. In this case, only the two spectra G A (k) and G B (k) corresponding to the signals S A and S B measured in window W 1 , obtained by FFT, are available when measuring.
Δt can therefore be readily obtained as mentioned above.
In this case, determination of the average traveltime t vm requires two reference signals of the same form as the signals received but of zero acoustic delay, therefore reproducing the acoustic waves as emitted. In practice, this type of signal is not directly accessible. In the calibration phase, the average traveltime t vm can be determined by means of the aforementioned echo method by filling the measuring system with a suitable fluid. It is also possible to use a test loop having another velocity measurement mode with the required accuracy. These examples are of course not limitative. The spectrum G A (k) is multiplied by: 2 π j kFe N ( t vm - Tf l )
The same procedure is applied to spectrum G B (k), and spectra G 0A (k) and G 0B (k) or reference spectra are thus obtained.
For measurement itself, the procedure of §4.1 is applied between G A (k) and G 0A (k) on the one hand and between G B (k) and G 0B (k) on the other, which leads to the values of τ A and τ B . tm=½(τ A +τ B )+Tf 1 is deduced therefrom.
Since interest is only in the phases of the spectra on a small number of points around the maximum of the amplitude, the reference spectra can be limited to the phase values on these points.
Velocity Calculation
Traveltimes tv 1 and tv 2 are obtained by calculating tv 1 =tvm+½Δt and tv 2 =tvm−½Δt, and relation (1) can be applied: V = L · Δ t 2 · tv 1 · tv 2 · cos α
or more simply with a negligible error: V = L · Δ t 2 · tv m 2 · cos α
The celerity C of the waves can be obtained by calculating: C = L tvm
The implementation device comprises (FIG. 9) an impulse generator G supplying transducers P A and P B , and an acquisition unit A intended for acquisition of the signals picked up by these transducers after their propagation in the fluid stream, that is coupled to a processing unit T programmed for real-time computation of the time intervals and phase lags according to the method described. Switching means (not shown) allows successive connection of each transducer to signal generator G for pulse emission and to acquisition unit A as soon as emission is finished.
Processing unit T preferably comprises a specialized signal processor such as a DSP of a well-known type.
The process proposed keeps its performance if the nature of the fluid and therefore the emission frequency are changed: sampling frequency Fe will be adapted accordingly.
An embodiment of the process has been described where significant phase changes in the velocity of flow of a fluid stream are measured on pulses simultaneously emitted from two points, one situated downstream from the other in relation to the direction of flow, in the direction of the other point. Without departing from the scope of the invention, any other wave emission-reception device can be adopted, with transducers arranged differently in relation to the fluid stream, possibly distinct for emission and reception, allowing comparison or accumulation of traveltimes of pulses propagating in the direction of flow and countercurrent, whether emitted simultaneously or successively.
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A process and device for measuring the velocity of flow of a fluid stream by measuring the difference between the respective traveltimes of acoustic pulses emitted by means of a generator (G) respectively between two points (P A , P B ) spaced out along the fluid stream, according to whether they are propagated upstream or downstream in relation to the direction of flow, a difference that is indicative of the displacement velocity of the fluid stream. Measurement of this traveltime difference comprises using an acquisition unit (A) coupled to a processing unit (P) allowing determination of the frequency spectrum of each pulse and measurement of the phase lag affecting at least part of the frequency spectrum of each pulse, resulting from the traveltime thereof. Measurement of the velocity of flow of the fluid stream and of the resulting flow rate is very accurate. The process can be applied in chemical industries, chromatography, etc.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional patent application of U.S. patent application Ser. No. 10/287,153, filed Nov. 4, 2002, which claims the benefit of the filing date of U.S. Patent Application No. 60/338,901, filed on Nov. 5, 2001, the entire contents of which are hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to compositions and methods for increasing patient compliance with therapies comprising the administration of aldehyde dehydrogenase inhibitors, and for preventing, ameliorating or treating alcoholism. Such compositions and methods may be used to facilitate alcohol cessation, and may comprise a combination of aldehyde dehydrogenase inhibitors and monoamine oxidase inhibitors.
[0004] 2. Description of the Related Art
[0005] Alcohol is a commonly abused drug. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), problematic alcohol use is divided into alcohol abuse and alcohol dependence.
[0006] Alcohol abuse involves recurrent alcohol consumption that negatively affects one's life, whereas alcohol dependence includes alcohol abuse and additionally symptoms of tolerance and withdrawal [McRae et al., “Alcohol and Substance Abuse,” In: Advances in Pathophysiology and Treatment of Psychiatric Disorders: Implications for Internal medicine, 85(d):779-801 (2001); Swift, R. M., New England J. Med. 340:1482-1490 (1999); Kick, S., Hospital Practice 95-106 (1999)]. In 1997, the estimated lifetime prevalence for alcohol abuse was 9.4% and for alcohol dependence was 14.1%, with men having significantly higher rates of dependence than women [McRae et al., supra]. Alcohol abuse and dependence commonly lead to other problems such as alcohol-related violence, motor vehicle accidents, and medical consequences of chronic alcohol ingestion including death [McRae et al., supra; Swift, supra].
[0007] One of the pharmacotherapies that have been suggested for treating alcoholism, including facilitating alcohol cessation, is the administration of agents that inhibiting the enzyme aldehyde dehydrogenase (ALDH), an enzyme involved in the removal of acetaldehyde, a toxic metabolite of alcohol. Examples of ALDH inhibitors include, e.g., disulfiram, coprine, cyanamide, 1-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, and any of their metabolites or analogs exhibiting ALDH-inhibiting activity including, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, and S-methyl N,N-diethylthiocarbamate sulfoxide. Patients who consume such inhibitors of ALDH experience mild to severe discomfort if they ingest alcohol. The efficacy of therapies using ALDH inhibitors depends on the patient's own motivation to self-administer the ALDH inhibitors, e.g., oral forms of the inhibitors, or to receive additional therapies, e.g., DEPO forms of disulfiram. In fact, patient compliance is a significant problem with these types of therapies.
[0008] Although multiple forms of ALDH exist. ALDH-I (also known as ALDH- 2 ) and ALDH-II (also known as ALDH- 1 ) are the major enzymes responsible for the oxidation of acetaldehyde. ALDH-I has a higher affinity for acetaldehyde than ALDH-II, and is thought to be the primary enzyme involved in alcohol detoxification [Keung, W. M., et al., Proc. Natl. Acad. Sci. USA 95:2198-2203 (1998)]. The discovery that 50% of the Asian population carries a mutation in ALDH-I that inactivates the enzyme, together with the low occurrence of alcohol abuse in this population supports the contention that it is this isozyme of ALDH that is primarily responsible for alcohol detoxification. Recent studies also implicate ALDH-I in the metabolism of monoamine neurotransmitters such as serotonin (5-HT) and dopamine (DA) [Keung, W. M., et al., Proc. Natl. Acad. Sci. USA 95:2198-2203 (1998)].
[0009] Disulfiram, also known as tetraethylthioperoxydicarbonic diamide, bis-diethylthiocarbamoyl disulfide, tetraethylthiuram disulfide, Cronetal™, Abstenil™, Stopetyl™, Contrain™, Antadix™, Anietanol™, Exhoran™, ethyl thiurad, Antabuse™, Etabuse™, RO-sulfiram, Abstinyl™, Thiuranide™, Esperal™, Tetradine™, Noxal™, Tetraeti™ [Swift, supra], is a potent irreversible inhibitor of ALDH-II and inhibits ALDH-I only slightly. Recent studies suggest that the inhibition of ALDH-I by disulfiram occurs indirectly via its metabolites, e.g., S-methyl-N,N-diethylthiocarbamate sulfoxide (DETC-MeSO) [Yourick et al., Alcohol 4:463 (1987); Yourick et al., Biochem. Pharmacol. 38:413 (1989); Hart et al., Alcohol 7:165 (1990); Madan et al., Drug Metab. Dispos. 23:1153-1162 (1995)]. Ingestion of alcohol while taking disulfiram results in the accumulation of aldehydes, which causes tachycardia, flushing, diaphoresis, dyspnea, nausea and vomiting (also known collectively as the disulfiram or disulfiram-ethanol reaction).
[0010] Although disulfiram has been available in the United States for many decades, patients frequently have difficulty complying with disulfiram treatment therapies. One reason for poor compliance is the lack of motivation for the patient to continue to take disulfiram, that is, other than self-motivation (i.e., there is no positive reinforcement for taking disulfiram). Another reason is because of the discomfort that arises if the patient ingests alcohol during disulfiram therapy [McRae et al., supra; Swift, R. M., supra; Kick, S., supra]. In fact, disulfiram has not proven to be useful in maintaining long-term sobriety [Kick, supra].
[0011] Coprine (N5-(hydroxycyclopropyl)-L-glutamine) has been shown to inhibit ALDH via its active metabolite, 1-aminocyclopropanol (ACP). U.S. Pat. No. 4,076,840 describes the synthesis and use of cyclopropyl benzamides, including coprine, for the treatment of alcoholism. In rat studies, coprine effectively suppressed ethanol consumption, and was shown to be a more potent inhibitor of ALDH as compared to disulfiram [Sinclair et al., Adv. Exp. Med. Biol. 132:481-487 (1980); U.S. Pat. No. 4,076,840].
[0012] Cyanamide has been described as an alcohol-sensitizing agent that is less toxic than disulfiram [Ferguson, Canad. M.A.J. 74:793-795 (1956); Reilly, Lancet 911-912 (1976)]. Although cyanamide is unable to inhibit either ALDH-I or ALDH-II in vitro, a reactive product of cyanamide catabolism inhibits both isozymes in vivo, indicating that cyanamide inhibits ALDH via a reactive species [DeMaster et al., Biochem. Biophys. Res. Com. 107:1333-1339 (1982)]. Cyanamide has been used for treating alcoholism but has not been approved in the U.S. Citrated calcium cyanamide is marketed in other countries as Temposil™, Dipsane™ and Abstem™, and plain cyanamide is marketed as Colme™ in Spain [See, U.S. Pat. No. 6,255,497].
[0013] Daidzin is a selective potent reversible inhibitor of ALDH-I, originally purified from an ancient Chinese herbal treatment for alcohol abuse. Its analogs include daidzein-7-O-[ω-carboxynonyl] ether (deczein), daidzein-7-O-[ω-carboxyhexyl] ether (hepzein), daidzein-7-O-[ω-carboxypentyl] ether (hexzein), daidzein, puerarin, and dicarboxymethyl-daidzein [Keung, Chemico - Bio. Int. 130-132:919-930 (2001)]. U.S. Pat. Nos. 5,204,369; 5,886,028; 6,121,010; and 6,255,497 describe methods for treating alcohol dependence or abuse using these compounds.
[0014] One of the major problems associated with therapies using ALDH inhibitors is ensuring patient compliance with the regimen. According to applicant's knowledge, there have been no teachings that suggest pharmacotherapies that adequately address this problem. For example, WO 99/21540 describes the administration of disulfiram in combination with compounds that bind to the D1 and/or D5 receptors and mimic dopamine to reduce craving for addictive substances in mammals. However, WO 99/21540 does not suggest pharmacotherapy for ensuring patient compliance with the regimen, which is important for the success of the treatment.
[0015] Another pharmacotherapy that has been suggested for treating alcoholism involves the inhibition of monoamine oxidases (MAOs). MAOs catalyze the oxidation of a variety of monoamines, including epinephrine, norepinephrine, serotonin and dopamine. MAOs are iron containing enzymes that exist as two isozymes A (MAOA) and B (MAOB). Various publications have described treatments for alcoholism using MAOB inhibitors [e.g., WO 92/21333, WO 96/37199]. WO 96/35425 discusses a treatment for alcoholism using a selective MAOB inhibitor in combination with a partial agonist of the 5-TH1A receptor. WO 00/71109 discusses a treatment for alcohol withdrawal symptoms using the MAOB inhibitor desmethylselegiline in combination with a second drug that treats alcohol withdrawal symptoms. U.S. Pat. No. 6,239,181 describes methods for alleviating symptoms associated with alcoholic neuropathy by administering the MAOB inhibitor, selegiline. However, none of the above references teach or suggest the use of MAOB inhibitors in therapies using ALDH inhibitors. Moreover, none of these references teach that MAOB inhibitors have a sustained effect on ensuring patient compliance with other therapies.
[0016] The present invention provides a solution for the deficiencies in traditional therapies using ALDH inhibitors to stop, prevent or reduce recidivism, thus, promoting compliance. The present invention also provides unexpectedly new and better compositions and methods for treating diseases that require the self-administration of an ALDH inhibitor.
SUMMARY OF THE INVENTION
[0017] The present invention provides compositions and methods for preventing, treating or reducing alcoholism comprising administering a therapeutically effective amount of an ALDH inhibitor in combination with an MAOB inhibitor.
[0018] There is provided in one embodiment of the present invention compositions and methods for increasing the rate of continuous abstinence, delaying resumption of abuse or dependence and/or preventing relapses in patients being treated for alcoholism.
[0019] There is further provided a method for increasing patient compliance with therapies that require self-administration of an ALDH inhibitor comprising the step of administering a therapeutically effective amount of a MAOB inhibitor.
[0020] According to one embodiment of the invention, the patient to be treated suffers from a disease requiring treatment with an ALDH inhibitor and consumes or can consume alcohol during therapy. The therapy does not involve forcing the patient to intake alcohol as part of the treatment. According to one preferred embodiment of this invention, the patient to be treated is suffering from alcoholism.
[0021] A composition according to the latter embodiment of the invention comprises an MAOB inhibitor and an ALDH inhibitor. The ALDH inhibitor may inhibit ALDH-I. The ALDH inhibitor may be, e.g., disulfiram, coprine, cyanamide, 1-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, or any of their metabolites or analogs exhibiting ALDH-inhibiting activity including, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, or S-methyl N,N-diethylthiocarbamate sulfoxide. In a more preferred embodiment, the ALDH inhibitor is disulfiram or an ALDH-inhibiting metabolite thereof. According to one preferred embodiment, the amount of disulfiram or an ALDH-inhibiting metabolite thereof administered is 500 mg per day.
[0022] In one embodiment, the MAOB inhibitor is, e.g., selegiline, pargyline, desmethylselegiline, rasagiline [R(+) N-propargyl-laminoindan], 3-N-phenylacetylamino-2,5-piperidinedione or caroxyazone. In a more preferred embodiment, the MAOB inhibitor is selegiline. According to one preferred embodiment, the amount of selegiline administered is 15 mg or less per day.
DETAILED DESCRIPTION OF THE INVENTION
[0023] An MAOB inhibitor according to this invention is a compound that inhibits MAOB but causes much less or no inhibition of MAOA activity, or a compound that selectively inhibits MAOB (e.g., within a particular dosage range). Hereinafter, the activity of an MAOB inhibitor as used according to this invention will be referred to as “selective MAOB inhibitor activity.”
[0024] In one embodiment, the MAOB inhibitor is selected from the group consisting of selegiline (Jumex®, Jumexal® Carbex®, Eldepryl®, Movergan®; Aptapryl®, Anipryl®; Eldeprine®; Plurimen®), desmethylselegiline, pargyline (Eudatin®, Supirdyl®, Eutonyl®) [U.S. Pat. No. 3,155,584], rasagiline [R(+)N-propargyl-laminoindan], 3-N-phenylacetylamino-2,5-piperidinedione, caroxyazone, AGN-1135 [WO 92/21333], MDL 72195 [WO 92/21333], J 508 [WO 92/21333], lazabemide [WO 00/45846], milacemide [WO 00/45846], IFO [WO 00/45846], mofegiline [WO 00/45846], and 5-(4-(4,4,4-trifluorobutoxy)phenyl)-3-(2-methoxyethyl)-1,3,4-oxadiazol-2(3H)-one [WO 00/45846]. In another embodiment, prodrugs or metabolites of the MAOB inhibitors are contemplated. Said metabolite should have substantially the same or better selective MAOB inhibitor activity as its unmetabolized form.
[0025] A prodrug of a MAOB inhibitor is a derivatized MAOB inhibitor that is metabolized in vivo into the active inhibitory agent. Prodrugs according to this invention preferably have substantially the same or better therapeutic value than the underivatized MAOB inhibitor. For example, a prodrug useful according to this invention can improve the penetration of the drug across biological membranes leading to improved drug absorption; prolong duration of the action of the drug, e.g., slow release of the parent drug from the prodrug and/or decrease first-pass metabolism of the drug; target the drug action; improve aqueous solubility and stability of the drug (e.g., intravenous preparations, eyebrows etc.); improve topical drug delivery (e.g., dermal and ocular drug delivery); improve the chemical and/or enzymatic stability of drugs (e.g., peptides); or decrease side effects due to the drug. Methods for making prodrugs are readily known in the art.
[0026] The term “MAOB inhibitor” according to this invention or metabolite thereof, as used herein includes pharmaceutically acceptable salts of those compounds. Pharmaceutically acceptable salts of MAOB inhibitors useful according to the methods of this invention are salts prepared from pharmaceutically acceptable reagents. In one embodiment, said pharmaceutically acceptable salt is a hydrochloride salt.
[0027] Methods known in the art for evaluating the activity of MAOB and MAOA can be used for selecting MAOB inhibitors according to this invention. For example, blood samples can be drawn to determine platelet MAO activity using radiolabelled benzylamine or phenylethylamine. (i.e., evaluating MAOB inhibitory activity). [Murphy, D. L., et al., Psychopharm. 62:129-132 (1979); Murphy, D. L., et al., Biochem. Med. 16:254-265 (1976); all incorporated by reference herein] In one embodiment, MAOB activity is decreased greater than 80% compared to MAOB enzyme activity before treatment. In a preferred embodiment, MAOB activity is decreased greater than 90% or 95% compared to MAOB activity before treatment.
[0028] MAOA inhibitory activity can, for example, be evaluated by measuring levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) or 5-hydroxyindoleacetic acid (5-HIAA) in the plasma of blood or in cerebral spinal fluid (CSF) by using gas chromatography-mass spectroscopy (gc-ms). [Murphy, D. L., et al., Clinical Pharmacology in Psychiatry, 3rd Series., Eds. Dahl, Gram, Paul, and Potter, Springer-Verlag: 1987; Major, L. F., et al., J. Neurochem. 39:229-231 (1979); Jimerson, D. C., et al., Biomed. Mass. Spectrom. 8:256-259 (1981); all incorporated by reference herein]. In one embodiment, after administration of the MAOB inhibitor, plasma MHPG levels should not be reduced lower than 45% of pretreatment levels of plasma MHPG. In a preferred embodiment, after administration of the MAOB inhibitor, plasma MHPG or CSF 5-HIAA levels should not be reduced more than 80% of pretreatment levels of MHPG or 5-HIAA levels, respectively.
[0029] ALDH inhibitors according to the invention are compounds that are capable of inhibiting the activity of one or more of the several isozymes of ALDH, e.g., ALDH-I and ALDH-IL. According to one embodiment, the ALDH is involved in alcohol metabolism. ALDH inhibitors according to this invention include, e.g., disulfiram, coprine, cyanamide, I-aminocyclopropanol (ACP), daidzin, cephalosporins, antidiabetic sulfonyl ureas, metronidazole, and any of their metabolites or analogs exhibiting ALDH-inhibiting activity. In another embodiment, the ALDH inhibitor is disulfiram or an ALDH-inhibiting metabolite thereof. Such metabolites include, e.g., S-methyl N,N-diethyldithiocarbamate, S-methyl N,N-diethyldithiocarbamate sulfoxide, and S-methyl N,N-diethylthiocarbamate sulfoxide.
[0030] The term “ALDH inhibitor” according to the invention or metabolite thereof, as used herein, includes pharmaceutically acceptable salts of those compounds.
[0031] The term “alcoholism” according to the invention includes alcohol abuse and alcohol dependence as described below.
[0032] The term “alcohol abuse” is defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Alcohol abuse as a maladaptive pattern of alcohol use that leads to clinically significant impairment or distress. Symptoms include one or more of the following occurring within a 12-month period: (1) recurrent alcohol use that results in a failure to fulfill major role obligations at work, school or home; (2) recurrent alcohol use in physically hazardous situations; (3) recurrent alcohol-related legal problems; and (4) continued alcohol use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance [McRae et al., supra; Swift, R. M., supra; Kick, S., supra].
[0033] Alcohol dependence occurs when symptoms of abuse are accompanied by three or more of the following: (1) tolerance defined by either: (a) a need for markedly increased amounts of alcohol to achieve intoxication or desired effect, or (b) markedly diminished effect with continued use of the same amount of alcohol; (2) withdrawal manifested by either: (a) characteristic withdrawal syndrome for alcohol or (b) alcohol taken to relieve or avoid withdrawal symptoms; (3) alcohol taken in larger amounts over a longer period than as intended; (4) a persistent desire or unsuccessful efforts to reduce or control drinking; (5) much time spent in activities necessary to obtain alcohol, use alcohol, or recover from its effects; (6) important social, occupational, or recreational activities being given up or reduced because of drinking; and (7) continued use despite knowledge of having a persistent or recurrent physical or psychological problem caused or exacerbated by alcohol [McRae et al., supra; Swift, R. M., supra; Kick, S., supra].
[0034] Alcohol abuse or dependence can also result in other symptoms including dyspepsia or epigastric pain, headache, diarrhea, difficulty in sleeping, fatigue, unexplained weight loss, apparent malnutrition, easy bruising, increased mean corpuscular volume, elevated transaminase levels (especially an aspartate transaminase level greater than of alanine transaminase), elevated γ-glutamyl transferase levels, iron-deficiency anemia, hepatomegaly, jaundice, spider angiomata, ascites, and peripheral edema. Behavioral symptoms associated with alcohol abuse or dependence include absenteeism from work or school, increasing irritability, difficulties with relationships, verbal or physical abuse, and depression [McRae et al., supra; Swift, R. M., supra; Kick, S., supra].
[0035] Alcoholism is often diagnosed using questionnaires, known to those of ordinary skill in the art, which are structured to obtain information related to the symptoms of alcohol abuse and/or dependence as outlined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The most commonly used screening test used for detecting alcohol abuse or dependence is the CAGE questionnaire [Kick, S., supra]. Alcoholics Anonymous describes another questionnaire.
[0036] A patient to be treated for, or protected against, the onset of alcoholism according to this invention can be a human, including children and adults, who are susceptible to or are suffering from alcoholism or who are being treated for alcoholism and are susceptible to experiencing relapses. A patient who is having difficulty complying with, or is being induced to comply with, treatments using ALDH inhibitors or their active metabolites according to this invention can be a human, including children and adults.
[0037] Compositions according the present invention comprise a pharmaceutically acceptable carrier together with an ALDH inhibitor and an MAOB inhibitor. According to one embodiment, the ALDH inhibitor is disulfiram, or a metabolite or prodrug thereof. According to another embodiment, the composition comprises 500 mg, 250 mg, 125 mg, or 60 mg of disulfiram, or metabolite or prodrug thereof. According to yet another embodiment, the MAOB inhibitor is selegiline, or a metabolite or prodrug thereof. According to a further embodiment, the composition comprises 15 mg or less of selegiline, or metabolite or prodrug thereof.
[0038] In a preferred embodiment, the composition comprises 500 mg, 250 mg, 125 mg or 60 mg of disulfiram, or metabolite or prodrug thereof, and 15 mg or less of selegiline, or metabolite or prodrug thereof. In a more preferred embodiment, the composition comprises about 60 mg of disulfiram, or a metabolite or prodrug thereof, and about 2 mg of selegiline, or a metabolite or prodrug thereof.
[0039] The effective dosage of a composition of the invention administered to a patient is at least an amount required to minimize, reduce or eliminate one or more symptoms associated with preventing or treating alcoholism, typically one of the symptoms discussed above. The magnitude of a prophylactic or therapeutic dose of the composition of the invention in the treatment of a patient will vary with the symptoms being exhibited, the severity of the patient's affliction, the desired degree of therapeutic response, the route of administration, and the concomitant therapies being administered. The dose and dose frequency will also vary according to the age, weight and response of the individual patient. Generally, however, treatment for alcoholism will be ongoing, although the intensity of treatment can vary depending on the patient's condition and exposure to biochemical and environmental stimuli that can warrant a variation on the treatment. Dosages can be administered in a single or multiple dosage regimen.
[0040] According to one preferred embodiment of the invention, the composition comprising 500 mg, 250 mg, 125 mg or 60 mg of disulfiram and 15 mg or less selegiline is administered twice a day, in the morning and at noon or late afternoon. In another preferred embodiment, a composition comprising about 125 mg of disulfiram and about 5 mg of selegiline is administered twice a day, in the morning and at noon or late afternoon.
[0041] Selegiline can be administered twice a day, in the morning and at noon or late afternoon. An initial daily non-oral dose can be at least about 0.01 mg per kg of body weight, calculated on the basis of the free secondary amine, with progressively higher doses being employed depending upon the response to therapy. The final daily dose can be between about 0.05 mg/kg of body weight to about 0.15 mg/kg of body weight (all such doses being calculated in the basis of the free secondary amine).
[0042] The present invention when employing selegiline is not limited to a particular form of selegiline and the drug can be used either as a free base or as a pharmaceutically acceptable acid addition salt. In the latter case, the hydrochloride salt is preferred. However, other salts useful in the invention include those derived from organic and inorganic acids such as, without limitation, hydrobromic acid, phosphoric acid, sulfuric acid, methane sulfonic acid, acetic acid, tartaric acid, lactic acid, succinic acid, citric acid, malic acid, maleic acid, aconitic acid, salicylic acid, thalic acid, embonic acid, enanthic acid, and the like.
[0043] The treating physician will know how to increase, decrease or interrupt treatment based upon the patient's response. Improvement for alcoholics or potentially relapsing alcoholics can be assessed by observing increased abstinence from consuming alcohol by the patient, following the methods of this invention, as compared to patients where therapy did not comprise the co-administration of a MAOB inhibitor. Improvement in compliance with self-administering ALDH inhibitors can be assessed by observing the increased duration over which patients, following the methods of this invention, take the ALDH inhibitor as compared to patients whose therapy did not comprise the co-administration of an MAOB inhibitor.
[0044] Any suitable route of administration can be employed for providing the patient with an effective dosage of a composition of this invention. For example, oral, peroral, buccal, nasal, pulmonary, vaginal, lingual, sublingual, rectal, parenteral, transdermal, intraocular, intravenous, intraarterial, intracardial intramuscular, intraperitoneal, intracutaneous, subcutaneous, sublingual, intranasal, intramuscular, and intrathecal administration and the like can be employed as appropriate. The term parenteral as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques. According to one preferred aspect of this invention, the route of administration is the oral route.
[0045] The composition can be conveniently presented in unit dosage form and prepared by any of the methods well-known in the art of pharmacy. Dosage forms can include tablets, scored tablets, coated tablets, pills, caplets, capsules (e.g., hard gelatin capsules), troches, dragees, powders, aerosols, suppositories, parenterals, dispersions, suspensions, solutions, transdermal patches and the like, including sustained release formulations well known in the art. In one preferred embodiment, the dosage form is a scored tablet or a transdermal patch. U.S. Pat. No. 5,192,550, incorporated herein by reference, describes a dosage form for selegiline comprising an outer wall with one or more pores, in which the wall is impermeable to selegiline but permeable to external fluids. This dosage form can have applicability for oral, sublingual or buccal administration.
[0046] The compositions of this invention can be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, and aqueous suspensions and solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are administered orally, the active ingredient (i.e., ALDH inhibitor and/or MAOB inhibitor) is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavoring and/or coloring agents can be added.
[0047] The compositions according to this invention can be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous or oleaginous suspension. This suspension can be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation can also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are mannitol, water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil can be employed including synthetic mono- or diglycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions can also contain a long-chain alcohol diluent or dispersant such as Ph. Helv or a similar alcohol.
[0048] Methods for making transdermal patches including selegiline transdermal patches have been described in the art. [See e.g., U.S. Pat. Nos. 4,861,800; 4,868,218; 5,128,145; 5,190,763; and 5,242,950; and EP-A 404807, EP-A 509761, EP-A 593807, and EP-A 5509761, all of which are incorporated by reference herein.]
[0049] Compositions of this invention can also be administered in the form of suppositories for rectal administration. These compositions can be prepared by mixing a compound of this invention with a suitable non-irritating excipient which is solid at room temperature but liquid at the rectal temperature and therefore will melt in the rectum to release the active components. Such materials include, but are not limited to, cocoa butter, beeswax and polyethylene glycols.
[0050] The compositions of this invention can be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and can be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art.
[0051] Patients can be regularly evaluated by physicians, e.g., once a week, to determine whether there has been an improvement in symptoms and whether the dosage of the composition of the invention needs to be adjusted.
[0052] According to the methods of this invention, the MAOB inhibitor can be included in the composition comprising the ALDH inhibitor. Alternatively, the MAOB inhibitor can be administered simultaneously with the composition comprising the ALDH inhibitor, or at any time during the treatment of the patient with the ALDH inhibitor.
[0053] The various terms described above such as “therapeutically effective amount,” are encompassed by the above-described dosage amounts and dose frequency schedule. Generally, a therapeutically effective amount of an MAOB inhibitor is that amount at which MAOB is inhibited but MAOA exhibits slight or no reduction in activity in the patient. Slight reduction in activity preferably comprises less than about 30% reduction in activity, more preferably less than about 20% reduction in activity, and yet more preferably less than about 10% reduction in activity. In one embodiment, the dosage of selegiline is an amount equal to or less than 15 mg per day. In another embodiment, the dosage of pargyline is equal to or less than 30 mg/day.
[0054] Throughout this specification, the word “comprise” or variations such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
STATEMENT REGARDING PREFERRED EMBODIMENTS
[0055] While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as defined by the appended claims. All documents cited herein are incorporated in their entirety herein.
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Compositions and methods for treating, preventing, or reducing alcoholism, in particular methods for increasing patient compliance with therapies that require the intake of an ALDH inhibitor comprising the step of administering a monoamine oxidase B inhibitor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 941,540, filed Sept. 15, 1978, being abandoned Sept. 15, 1979, which in turn is a continuation-in-part of application Ser. No. 767,388, filed Feb. 10, 1977 and abandoned Sept. 15, 1978, which in turn is a continuation-in-part of application Ser. No. 581,094, filed May 27, 1975 and abandoned Feb. 11, 1977, which in turn is a continuation-in-part of application Ser. No. 413,372, filed Nov. 6, 1973 and abandoned Tuesday, May 27, 1975.
BACKGROUND OF THE INVENTION
This invention relates to coating compositions based on a water-borne reaction product of a carboxyl-functional polymer, an epoxide, and a tertiary amine, having general utility in coating metallic and paper substrates. It is more particularly directed to coating compositions useful as automotive and can coatings.
Coatings of the prior art are often dissolved or dispersed in organic solvents. Among commonly utilized thermosetting compositions are those based on epoxy resins crosslinked with nitrogen resins, usually in an acid catalyzed process.
Increased awareness of the environmental hazards of allowing organic solvent vapors to enter the atmosphere, the desirability of a single system that can be applied not only by the more conventional techniques of spray, roller or flow coating but also by electrodeposition, and the economy resulting from the substitution of water for some or all of the solvents in a coating composition, are all factors mitigating in favor of water-borne coating compositions.
Aqueous epoxy-acrylic-amine coating compositions of other investigators, including U.S. Pat. Nos. 3,969,300--Nagata (1976) and 4,021,396--Wu (1977) are less stable than desired or lack advantages of the present invention.
The composition of this invention is an aqueous solution or dispersion of the reaction product of a carboxyl-functional polymer, a terminally functional epoxy resin, and a tertiary amine. Such a water-borne system can optionally contain a crosslinking agent, is stable, and can be applied to metallic substrates by spray, roller, dip or flow coating or by electrodeposition at the anode and to paper.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a water-borne coating composition based on polymeric quaternary salts of polymeric acids which are the reaction product of:
(A) not less than 50%, based on the weight of (A) plus (B), preferably not less than 65%, most preferably about 78%, of an epoxy resin containing, on the average, two terminal 1,2-epoxy groups per molecule and having an epoxy equivalent weight of 750-5000, preferably about 1500-4000, most preferably about 3000;
(B) a carboxyl-functional polymer in an amount sufficient to provide at least 1.25, preferably at least about 1.75, most preferably about 4.6, equivalents of carboxyl groups, when the source of the carboxyl group is a mono-protic acid, and at least 2.0 equivalents of carboxyl groups, when the source of such groups is a diprotic acid, per equivalent of 1,2-epoxy groups in the epoxy resin of (A), said polymer having a weight average molecular weight (determined by light scattering) of 10,000-160,000, preferably about 10,000-80,000, most preferably about 13,000-18,000, and an acid number of 100-500, preferably about 150-350, most preferably about 300; and
(C) an aqueous solution of at least 1.25, preferably at least about 1.75, most preferably about 3.0, equivalents of a tertiary amine per equivalent of 1,2-epoxy groups in the epoxy resin of (A), said tertiary amine being selected from the group consisting of R 1 R 2 R 3 N, pyridine, N-methyl pyrrole, N-methyl piperidine, N-methyl pyrrolidine, N-methyl morpholine, and mixtures therein and wherein R 1 and R 2 are substituted or unsubstituted monovalent alkyl groups containing one or two carbon atoms in the alkyl portion and R 3 is a substituted or unsubstituted monovalent alkyl group containing 1-4 carbon atoms; and
(D) optionally, 10-90% of the amount required for stoichiometric reaction with the carboxylfunctional polymer of (B) of at least one primary, secondary or tertiary amine or monofunctional quaternary ammonium hydroxide, wherein Y is at least about 6+0.75(2 X ) wherein Y is the milliequivalent of carboxyl groups neutralized by primary, secondary or tertiary amine or monofunctional quaternary ammonium hydroxide per 100 grams of acid polymer plus epoxy, and X is the epoxy equivalent weight divided by 1000; and wherein for increasing ratios of carboxyl groups to 1,2-epoxy groups, the amount of amine is increased to keep the carboxyl-functional polymer water dispersible. Preferably, components (A), (B) and (C) are capable of forming a hydrogel structure with components (A), (B) and (C) comprising about 0.1-50% of the coating composition and the remainder comprising water and, optionally, organic liquid(s) in a volume ratio of from 70:30 to all water, sometimes preferably 80:20. (Percentages, proportions and ratios herein are by weight except where indicated otherwise.)
The water-borne coating composition can be crosslinked without the addition of a crosslinking agent or, optionally, it can contain crosslinking agents such as a nitrogen resin or a phenolic resin, as well as additives commonly utilized in coating compositions such as pigments, fillers, UV absorbers, and the like.
DESCRIPTION OF THE INVENTION
The water-borne coating composition of the invention is a solution or dispersion of the reaction products of an epoxy resin, a tertiary amine, and a carboxyl-functional polymer. By mixing these components in a random order and utilizing aqueous solutions of highly specific tertiary amines such as dimethyl ethanol amine, a stable, water soluble or dispersible salt of a polymeric quaternary ammonium hydroxide and a carboxyl-functional polymer results which can be crosslinked without the addition of external crosslinking agents. The optional addition of an external crosslinking agent, such as a nitrogen resin, also affords a crosslinkable solution or dispersion which is stable at room temperature. Both compositions, the salt and the solution or dispersion containing an external crosslinking agent, are infinitely dilutable with water.
Whether the coating composition is a solution or a dispersion is largely dependent on the nature of the particular amine used, the stoichiometry of the system, and the epoxy equivalent weight. Even when the composition is opaque some of the resinous components may be dissolved, and when the composition appears to be a clear solution it is possible that small amounts of the components are in a dispersed state. For sake of simplicity, hereafter the term "dispersion" will be used to denote the water-borne coating composition.
The dispersion, with or without an external crosslinking agent, as prepared, usually has a pH of above 7 and a nonvolatile content of up to 50%. Upon drying, a hard, solvent-resistant film having excellent resistance to acids, bases, hot water, and detergent results.
The low molecular weight epoxy resins to be utilized in the present invention are commonly known in the art. One class of such resins has the generalized formula ##STR1## wherein R is an alkylene group of 1-4 carbon atoms and n is an integer from 1-12. The epoxy resins utilized in this invention contain an average of two terminal 1,2-epoxy groups per molecule and are in the epoxy equivalent weight range of 750-5000, preferably 1500-4000. They can also contain substituted aromatic rings.
One such preferred epoxy resin is "Epon 1004" where R is isopropylidene, the average value of n is 5, having an epoxy equivalent weight of 875-1025, with an average of about 950±50. The epoxy equivalent weight is defined as the grams of resin containing 1 gram-equivalent of epoxide as measured by ASTM-D-1652. The coating composition containing "Epon 1004" affords a glossy, flexible, chemically-resistant film. Another preferred epoxy resin is "Epon 1007" where R is isopropylidene, the average value of n is 11, having an epoxy equivalent weight of 2000-2500, with an average of about 2175±50. The coating composition containing "Epon 1007" affords glossy, tough, flexible films upon cure. Another preferred epoxy is an analog of "Epon 1009" with an average epoxy eqivalent weight of 3000 made by chain extending "Epon 829" (EW 195) with bisphenol A.
The quantity of the epoxy resin to be utilized in the coating composition of this invention is determined in relation to the amount of carboxyl-functional polymer and the relative amounts are dependent on the end use application of the coating but there must be at least 50%, preferably in the range of 65-90%, of epoxy resin present. There must be, furthermore, at least 1.25, preferably at least 1.75, and most preferably about 4.6, equivalents of carboxyl groups per equivalent of 1,2-epoxy groups in the epoxy resin. This minimum equivalent requirement is valid for those carboxyl-functional polymers which contain monoprotic acids derived from alpha,beta-ethylenically unsaturated acid monomers such as acrylic acid, methacrylic acid, monoesters of alkanols having 1-8 carbon atoms with diacids, such as maleic acid, itaconic acid, fumaric acid, mesaconic acid, citraconic acid and the like, and mixtures thereof. For those carboxyl-functional polymers which contain diprotic acids derived from diacids such as maleic acid, itaconic acid, fumaric acid, mesaconic acid, citraconic acid, and mixtures thereof, the minimum requirement is 2.0 equivalents, preferably at least 2.5 equivalents, of carboxyl group per 1,2-epoxy groups. Usually, no more than 10.0, and preferably no more than 6.0, equivalents of carboxyl groups, per equivalent of 1,2-epoxy groups, will be present.
The carboxyl-functional polymers utilized in this invention are prepared by conventional free radical polymerization techniques from at least one ethylenically unsaturated monomer and at least one ethylenically unsaturated acid monomer. The choice of the alpha,beta-unsaturated monomer(s) is dictated by the intended end use of the coating composition and is practically unlimited. A variety of acid monomers can be used; their selection is dependent on the desired final polymer properties.
This acid monomer can be an ethylenically unsaturated acid, mono-protic or diprotic, anhydride or monoester of a dibasic acid, which is copolymerizable with the other monomer(s) used to prepare the polymer.
Illustrative monobasic acids are those represented by the structure ##STR2## where R is hydrogen or an alkyl radical of 1-6 carbon atoms.
Suitable dibasic acids are those represented by the formula ##STR3## where R 1 and R 2 are hydrogen, an alkyl radical of 1-8 carbon atoms, halogen, cycloalkyl of 3-7 carbon atoms or phenyl, and R 3 is an alkylene radical of 1-6 carbon atoms. Half-esters of these acids with alkanols of 1-8 carbon atoms are also suitable.
The most preferred acid monomers are acrylic acid, methacrylic acid, and itaconic acid.
The acid number of the polymers is 100-500, which corresponds to concentrations of about 10-77% of the acid monomers by weight of the polymer. The acid number is the number of miligrams of potassium hydroxide required to neutralize one gram of the polymer. For purposes of illustration, an acid number of 100 corresponds to the presence in the polymer of either 12.8% acrylic acid, 15.3% of methacrylic acid, 11.5% of itaconic acid, or 10.3% of maleic or fumaric acid. An acid number of 500 corresponds to 64% of acrylic acid, 76.5% of methacrylic acid, 57.5% of itaconic acid, or 51.5% of maleic or fumaric acid in the polymer. Preferred acid number values are 150-350.
Vinyl aromatic monomers are commonly utilized to be copolymerized with the acid monomers. They are represented by the structure: ##STR4## where R, R 1 , R 2 , and R 3 are hydrogen or an alkyl radical of 1-5 carbon atoms. Illustrative of these monomers are styrene, α-methyl styrene, vinyl toluene, and the like. The best polymers, in terms of final film properties, are those in which this type of monomer is styrene. The vinyl aromatic monomers can be present from 0-80% of the carboxyl-functional polymer, preferably from 40-80%, most preferably from 40-70%, and specifically at concentrations of about 42, 53, and 66%. For some purposes 10-45% may be preferred and, in some applications, the polymer contains no such monomer.
Other commonly utilized monomers are the α,β-unsaturated nitriles represented by the structure: ##STR5## where R and R 1 are hydrogen, an alkyl radical of 1-18 carbon atoms, tolyl, benzyl or phenyl, and R 2 is hydrogen or methyl. Most commonly utilized are acrylonitrile and methacrylonitrile. The nitrile monomer can be present from 0-40% based on the carboxyl-functional polymer. The polymers preferably contain 10-30% and more preferably 18-22% of the polymer, of the nitrile monomer. For certain purposes it may be desirable to use 5-10% of the nitrile monomer and in some cases no such monomer is included in the polymers.
Other suitable monomers are esters of acrylic acid, methacrylic acid or mixtures thereof with C 1 -C 16 alkanols. Preferred esters are the methyl, ethyl, propyl, n-butyl isobutyl, and 2-ethylhexyl esters of acrylic acid or methacrylic acid or mixtures of such esters. These esters can be present in concentrations of 0-97%, preferably 50-90% for automotive finishes and coil coatings and, for can coatings and appliance finishes, preferably 0-50%.
One can also utilize hydroxyalkyl (meth)acrylate monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate or mixtures thereof. Up to 20% of such ester(s) can be incorporated.
It may be desirable, for certain uses, to include in the polymer acrylamide, methacrylamide or an N-alkoxymethyl (meth)acrylamide such as N-isobutoxymethyl (meth)acrylamide. Alternatively, a polymer containing copolymerized acrylamide or methacrylamide can be post-reacted with formaldehyde and an alkanol to produce an N-alkoxymethylated polymer.
Choice of the particular monomers to be utilized is made with respect to the end use of the coating composition. Preferred polymer compositions include: styrene/acrylonitrile/α,β-ethylenically unsaturated acid//45-84/10-30/15-54, for can coating; styrene/acrylonitrile/alkyl (meth) acrylate/α,β-ethylenically unsaturated acid//30-60/10-30/10-50/15-54, for can coatings and applicance finishes; styrene/alkyl (meth)acrylate/α,β-ethylenically unsaturated acid//20-70/10-60/15-54 or, even more preferably, 35-60/30-50/15-54, for automotive topcoats and primers; methyl methacrylate/alkyl (meth)acrylate/α,β-ethylenically unsaturated acid//20-40/30-74/15-54, for automotive and coil coating applications. Any of the above can also include hydroxylalkyl (meth)acrylate and/or (meth)acrylamide. The alkyl group of the alkyl (meth)acrylate monomer is preferably ethyl, n-butyl, iso-butyl or 2-ethyl-hexyl.
The carboxyl-functional polymers can be prepared by polymerizing suitable monomers, in proper amounts, in an organic liquid medium. In general, this liquid is an organic liquid capable of medium hydrogen bonding, or a combination of this liquid with less than about 50% of an organic liquid capable of strong hydrogen bonding.
Preferably, the liquid medium for the polymerization is an alcohol mixture, generally 62% butanol and 38% of butyl cellosolve. Other media which could be used include either water-soluble or insoluble ketone. Optionally, the ketone can also contain less than about 50% of an ethylene glycol- or diethylene glycol monoalkyl ether (where the alkyl group contains 1-4 carbon atoms), or diacetone alcohol, and/or an alkanol of 1-4 carbon atoms or an alkanediol of 1-7 carbon atoms. A preferred medium is methyl ethyl ketone used by itself. Another preferred medium for the polymerization is a mixture of methyl ethyl ketone and ethylene glycol monobutyl ether.
A catalyst or polymerization initiator is ordinarily used in the polymerization of the carboxylfunctional polymers, in the usual amounts. This can be any free radical initiator that decomposes with a halflife of 0.5 to 2.5 hours at the reflux temperature of the organic liquid medium being used. Tertiary butyl perbenzoate, tertiary butyl peroxypivalate, and tertiary butyl peroxyisobutyrate are preferred.
The polymers utilized in the water-borne coating composition of this invention have a weight average molecular weight, as determined by light scattering or, more conveniently, gel permeation chromatography, using a polystyrene standard, calibrated by light scattering methods of about 10,000-160,000. The preferred weight average molecular weight range is 10,000-80,000. For some applications a 13,000-18,000 molecular weight is preferred.
During the preparation of the coating composition of this invention, an aqueous solution of a tertiary amine, specified below, is brought in contact with a solution of an epoxy resin in organic liquid(s) or with a solutin of an epoxy resin and a carboxyl-functional polymer. A wide variety of organic liquids can be used to dissolve the epoxy resins and the carboxyl-functional polymers. Among the most commonly used solvents are alcohols such as isopropanol, the butyl alcohols, 2-hydroxy-4-methyl-pentane, 2-ethylhexyl alcohol, cyclohexanol, glycols such as ethylene glycol, diethylene glycol, 1,3-butylene glycol, ether alcohols such as ethylene glycol mono-ethyl ether, ethylene glycol mono-butyl ether, diethylene glycol mono-methyl ether, mixtures thereof, and many aliphatic and aromatic hydrocarbons if used admixed with at least one of the above.
While the exact mode of the reaction is not fully understood, it is believed that the tertiary amine first reacts with the carboxyl-functional polymer to form the corresponding salt which, in turn, can dissociate to allow the amine to react with the 1,2-epoxy groups of the epoxy resin. It is also possible, however, that the tertiary amine reacts directly with the 1,2-epoxy groups. In either case, the resulting quaternary ammonium hydroxide can react with the carboxyl-functional polymer to yield a polymeric quaternary ammonium-amine mixed salt of a polymeric acid.
The reaction of tertiary amines with materials containing epoxy groups, to yield adducts containing quaternary ammonium groups, is known. Such reaction, when carried out in presence of water, can afford a product that contains both a hydroxyl group and a quaternary ammonium hydroxide. The reaction can be represented schematically as follows: ##STR6## While most tertiary amines react with epoxy resins to form quaternary ammonium hydroxides, the preparation of the water-borne coating composition of this invention is carried out utilizing at least one tertiary amino selected from the group: R 1 R 2 R 3 N, N -methyl pyrrolidine, N-methyl morpholine, pyridine, N-methyl pyrrole, N-methyl piperidine, and mixtures thereof, wherein R 1 and R 2 are substituted or unsubstituted monovalent alkyl groups containing one or two carbon atoms in the alkyl portion and R 3 is a substituted or unsubstituted monovalent alkyl group containing 1-4 carbon atoms. Some examples of R 1 R 2 R 3 N are: trimethyl amine, dimethyl ethanol amine (also known as dimethyl amino ethanol), methyl diethanol amine, ethyl methyl ethanol amine, dimethyl ethyl amine, dimethyl propyl amine, dimethyl 3-hydroxy-1-propyl amine, dimethylbenzyl amine, dimethyl 2-hydroxy-1-propyl amine, diethyl methyl amine, dimethyl 1-hydroxy-2-propyl amine, and mixtures thereof. Most preferably trimethyl amine or dimethyl ethanol amine is used.
The generation of a polymeric quaternary ammonium hydroxide which is water soluble or dispersible when in presence of a nitrogen resin crosslinking agent is described in U.S. Pat. No. 4,076,676, granted Feb. 28, 1978, and its relevant portions are hereby incorporated by reference.
The amount of tertiary amine needed in the preparation of the water-borne coating composition of this invention is determined by two factors. As a minimum, there is required at least 1.25 equivalents of tertiary amine per equivalent of 1,2-epoxy groups, preferably at least 1.75 equivalents, more preferably 3.0, for the formation of stable dispersions. As the ratio of the number of carboxyl groups in the carboxyl-functional polymer to the number of 1,2-epoxy groups in the epoxy resin increases, the amount of amine is also increased to keep the carboxyl-functional polymer water dispersible. This excess amine is believed to form a salt with some or all of the excess carboxyl groups of the polymer. It is preferred that no excess amine, over the total number of equivalents of carboxyl groups, be used in the coating composition of this invention. The amine utilized in excess of the 1.25 equivalents of the highly specific tertiary amine per equivalent of 1,2-epoxy groups need not be the same as, nor does it necessarily have to be selected from the group of, the highly specific tertiary amines. Any primary, secondary of tertiary amine or monofunctional quaternary ammonium hydroxide can be utilized in neutralizing carboxyl groups of the carboxyl-functional polymer which are not already neutralized. Among such tertiary amines are included: triethyl amine, diethyl ethanol amine, dimethyl cyclohexyl amine, triethanol amine, tributyl amine, dimethyl n-butyl amine, tripropyl amine, dimethyl lauryl amine, and γ-picoline. Primary and secondary amines preferably should not be used along with tertiary amines in the neutralization of the epoxies because unwanted covalent bonds could be formed, and this can interfere with the desired hydrogel formation.
The water-borne coating composition of this invention can be prepared without regard to the sequence of addition of the various components. It is preferred, however, to first dissolve the epoxy resin in the carboxyl-functional polymer, in presence of suitable organic liquids. Addition of a suitable tertiary amine, usually dissolved in water, completes the preparation of the polymeric quaternary ammonium salt of a polymeric acid. Additional water can then be added to achieve the final volume rate of water and organic liquid of from 70:30 preferably to 90:10. Additional amine can also be added to insure dispersibility.
A preferred ratio of tertiary amine to water is approximately 1:5 by weight.
The reaction can be carried out between room temperature and below the boiling point of the reaction medium, preferably between 50°-100° C., most preferably 90°-100° C. In this temperature range there is a rapid rate of reaction.
In another preferred method of preparation of the coating composition, an epoxy resin is dissolved in a suitable organic liquid such as the mono-butyl ether of ethylene glycol or diethylene glycol, followed by the addition of a suitable tertiary amine. After the formation of the polymeric quaternary ammonium hydroxide is substantially complete, a carboxyl-functional polymer, dissolved in a suitable organic liquid is mixed with it with agitation. This latter solution can also contain any additional primary, secondary or tertiary amine, dissolved in water, necessary for dispersability of the coating composition. Mixing of the components completes the preparation of the water-borne coating composition. This sequence of steps can also be carried out between room temperature and temperatures below the boiling point of the reaction media.
Yet another preferred method of preparation comprises the steps of dissolving the carboxyl-functional polymer in a suitable organic liquid, addition of an aqueous solution of a suitable tertiary amine, mixing in of an epoxy resin, and heating, preferably between 50°-100° C. and, more preferably, between 90°-100° C., followed by the requisite amount of water to obtain the final water-to-organic liquid volume ratio of from 70:30 to 90:10.
The polymeric quaternary ammonium-amine mixed salt of the carboxyl-functional polymer of the water-borne coating composition of this invention preferably is a complex hydrogel structure. It is the generation, during the epoxy/carboxyl/amine reaction, of such a hydrogel structure which affords the solubility or dispersibility, and stabilization, in water of the coating composition. A possible schematic formula is shown by the formula below. The exact nature of the bonding is not known. The number of carboxyl groups in the schematically shown polymer molecules and of the relative portion of free acid groups to the amine salt groups are determined by the stoichiometry employed during the preparation of the coating composition. The schematic representation is shown to further the understanding of the nature of the invention: ##STR7## where M.sup.⊕ is hydrogen or a protonated primary, secondary or tertiary amine or a monofunctional quaternary ammonium group and ##STR8## is formed from a tertiary amine selected from the group: R 1 R 2 R 3 N, N-methyl pyrrolidine, N-methyl morpholine, pyridine, N-methyl pyrrole, N-methyl piperidine, and mixtures thereof, wherein R 1 and R 2 are substituted or unsubstituted monovalent alkyl groups containing one or two carbon atoms in the alkyl portion and R 3 is a substituted or unsubstituted monovalent alkyl group containing 1-4 carbon atoms.
The water-borne coating composition of this invention is a stable solution or dispersion and can be used as prepared. It can be crosslinked without the addition of an external crosslinking agent and can also be crosslinked with external crosslinking agent such as phenol formaldehyde resins or, preferably, nitrogen resins.
The nitrogen resins are well known. They are the alkylated products of amino-resins prepared by the condensations of at least one aldehyde with at least one of urea, N,N'-ethyleneurea, dicyandiamide, and aminotriazines such as melamines and guanamines. Among the aldehydes that are suitable are formaldehyde, revertible polymers thereof such as paraformaldehyde, acetaldehyde, crotonaldehyde, and acrolein. Preferred are formaldehyde and revertible polymers thereof. The amino-resins are alkylated with at least one and up to and including six alkanol molecules containing 1-6 carbon atoms. The alkanols can be straight chain, branched or cyclic.
Among the preferred nitrogen resins are partially methylated melamines, partially butylated melamines, hexaethoxymethylmelamine, hexamethoxymethylmelamine, dimethoxytetraethoxymethylmelamine, dibutoxytetramethoxymethylmelamine, butylated benzoguanamine, partially methylated urea, fully methylated urea, fully butylated urea hexabutoxymethylmelamine, and mixtures thereof.
These nitrogen resins can be blended directly into the coating composition at the completion of the preparation or before final dilution with water, either as a solid or as a solution in some miscible organic liquid.
The nitrogen resins are ordinarily added to the compositions of the invention at concentrations ranging from 5 to 35%, preferably 8 to 20%, even more preferably 10 to 15%. The exact amount will be dictated primarily by the final properties desired of the composition and can be determined by one skilled in this art.
In the claims, the term "consisting essentially of" means not including other ingredients in amounts which change the basic and novel characteristics of the invention, including providing an aqueous acid-polymer-modified epoxy coating composition that can form a hydrogel and is useful as an interior coating for cans. Other commonly utilized additives such as coalescing aids, flow-control agents, pigments and the like can be added, in the usual amounts, if this appears necessary or desirable.
The water-borne composition can be applied by a variety of techniques and to a variety of substrates known in industry. For example, the coating composition of this invention can be utilized in the can manufacturing industry which utilizes mainly metallic cans, many of them cylindrical, made from aluminum, tin-free steel, electrolytic tin-plate, and quality-as-rolled steel, among others. Cans utilized for packaging and shipping food and beer or other beverages are mostly of the three-piece or the two-piece drawn-and-ironed (D and I) variety. Cans constructed from three pieces (body, top and bottom) can be roller coated before the metallic sheet is formed into the body of the can or can be spray coated after partial fabrication. The D and I cans, where the metal sheet is stamped to form a cylindrical body closed at one end, are generally spray coated.
The coating composition of this invention can also be applied by electrodeposition. In the electrodeposition process the water-borne composition is placed in contact with an electrically conductive cathode and an electrically conductive anode, with the surface to be coated being the anode. During the process an adherent film is deposited at the anode. The substantial lack of film formation at the cathode is thought to be due to the preferential dissociation of the amine salt of the carboxyl groups over the polymeric quaternary ammonium salt of the carboxyl groups. It is believed that both electronic and steric factors are involved in the control of the dissociation. The negatively charged carboxylate anion migrates to the anode. The nitrogen resin crosslinking agent, if present in the coating composition, also migrates, in a possible physical entanglement with the polymeric quaternary ammonium salt of the carboxyl-functional polymer, to the anode.
The conditions under which the electrocoating is carried out are similar to those used in the electrodeposition of other types of coatings. The applied voltage can be varied, can range from 1 to 1000 volts, and is typically between 25 and 500 volts. The current density is usually between about 1 milliampere and 100 milliamperes per square centimeter. The current density tends to decrease during the coating process as the coating thickness increases. The coating time can vary from 1 to 20 seconds or longer and is typically between 1 and 5 seconds for coating cans.
The concentration of the coating composition depends upon the process parameters to be used and is not generally critical. Ordinarily the film-forming components comprise 0.1-50% and preferably 5-30%, for conventional coating methods, and 1-20%, for electrodeposition, of the total composition, the remainder being water and organic liquid(s). The latter are present in a volume ratio of from 90:10 preferably to 70:30.
The freshly deposited films are capable of being immediately dried and/or crosslinked, without regard to the method of coating used to obtain them.
The coating compositions of this invention can be dried to useful films as is or can be cured thermally as is or when containing, for example, a nitrogen resin crosslinking agent. After the composition has been applied to the substrate, baking at elevated temperatures brings about the desired crosslinking. Temperatures of 150° C. to 260° C., for 0.1 to 30 minutes, are typical baking schedules utilized.
The water-borne coating composition of this invention is useful in a variety of applications. This coating composition finds particular utility in the can industry where the composition can be applied to the interior of two-piece drawn-and-iron and three-piece beer and beverage cans, to the exterior of three-piece beer and beverage cans, to the interior and/or exterior ends of two- or three-piece cans or two- or three-piece sanitary cans. When the coating composition of this invention is applied to the interior of food and beer or beverage cans by spray-coating, a thin uniform film is deposited which, after curing, corresponds to a coating weight of 0.3 to 1.3 milligrams per square centimeter (2-8 milligrams per square inch). Coatings utilized as an interior enamel have excellent taste and odor characteristics, that is to say, low extractables and sorption to prevent taste adulteration.
The water-borne composition also has utility, expecially when crosslinked with a nitrogen resin, in automotive primer, appliance finish, and coil coating applications, the final coated articles having especially desirable hardness and acid, base, solvent, and detergent resistance properties. The cured coatings are also resistant to salt spray and "processing." This latter property is tested in a steam-pressure cooker at approximately 120° C.
The invention is further illustrated by the following examples.
EXAMPLE 1
(A)
A polymer having the composition of styrene/ethyl acrylate/methacrylic acid//34.7/40/25.3 (percent by weight) is prepared similarly to the method of preparation used for the polymer of Example 3(A). The final polymer has an acid number of 164 and a solids content of 55%.
(B)
To a 457.9-gram portion of the polymer from (A) above, are added 666.6 grams of "Epon 1007" (average epoxy equivalent weight about 2,175); butyl cellosolve, 81.5 grams; and butyl carbitol, 81.5 grams. The mixture is heated to between 80°-100° C. and mixed to dissolve the epoxy resin. A solution of 65.9 grams of dimethylamino ethanol in 131.8 grams of water is then added and the reaction mixture is maintained at 75°-80° C. for 30 minutes. To this mixture is then added a fully alkoxylated methoxybutoxymethyl melamine, 181.5 grams, followed by, after mixing for 5 minutes, 2333.1 grams of water. The mix is stirred at 50°-60° C. until uniform. A stable dispersion is obtained having a solids content of 27.5% and a pH of 9.0.
The resulting product contained about 72.6% epoxy resin, 27.4% acrylic resin, by weight, and the equivalent ratios of acid polymer/amine/epoxy was about 2.4/2.4/1. X was 2.175, and Y was 47.
The product is applied to untreated aluminum with a #25 wire-wound rod and baked at 205° C. to afford a coating weight of 25.9 mg/4 square-inch surface. Comparison test data, with product from (C) below, are shown in (D) below.
(C)
Example 1(B) is repeated with the exception that no external crosslinking agent is utilized. The following quantities are added in the same manner as in (B) above:
______________________________________ Grams______________________________________Polymer [from (A) above] 548.4"Epon 1007" 798.4Butyl Cellosolve 54.6Butyl Carbitol 54.6Dimethyl Ethanol Amine 79.0Water (for the amine) 157.9Water 2307.1______________________________________
The stable dispersion so obtained has a solids content of 27.5% and a pH of 9.0. This is applied to untreated aluminum as above and baked to afford a coating weight of 25.1 mg/4 square inch. Test data are shown in (D) below.
(D)
The coated panels from (B) and (C) above are tested as follows: The hard, glossy films from both (B) and (C) pass 40 rubs with methyl ethyl ketone and show no blush and excellent adhesion after a 30-minute exposure to boiling water.
These results indicate that good film properties can be obtained with this invention in presence or absence of an external crosslinking agent.
EXAMPLE 2
(A)
To a suitable reactor is charged the following parts by weight:
______________________________________Styrene 83.318Ethyl Acrylate 78.868Methacrylic Acid 71.850Acetone 35.226Monobutyl Ether of Ethylene Glycol 81.076Normal Butanol 28.518______________________________________
The charge is heated to 85° C. and the heat is turned off. A solution of 1.403 parts of tertiary butyl peroxy isobutyrate in 2.349 parts of monobutyl ether of ethylene glycol is added and the batch exotherms to reflux temperature and is held there for ninety minutes. A second addition of 1.403 parts of tertiary butyl peroxy isobutyrate in 2.349 parts of monobutyl ether of ethylene glycol is added rapidly and reflux is maintained for an additional 60 minutes. A third addition of 1.403 parts of tertiary butyl peroxy isobutyrate in 2.349 parts of monobutyl ether of ethylene glycol is added rapidly and reflux is maintained for an additional 60 minutes. 69.890 parts of normal butyl alcohol and 43.611 parts of monobutyl ether of ethylene glycol are added. 35.226 parts of acetone is removed by distillation. 54.373 parts of diemethylethanol amine and 326.240 parts of deionized water are added. The acid number of the product is 200.
(B)
To a suitable reactor is charged the following parts by weight:
"Epon 829": 1854.6
Bisphenol A: 985.4
Monobutyl Ether of Ethylene Glycol: 424.8
The charge is heated to 130°-140° C. and allowed to exotherm to about 200° C. Temperature is maintained above 165° C. for two hours after peak exotherm temperature is reached. 778.7 Parts of normal butanol are added.
The "Epon 829" has an epoxy equivalent weight of about 195, and it is chain-extended by the bisphenol A to an epoxy equivalent weight of about 3000.
The batch is cooled to 100° C. 2358.8 Parts of the neutralized acrylic polymer prepared in A are added. The batch is maintained at 80°-85° C. for 25 minutes. 5597.7 Parts of deionized water, preheated to 80° C. are added evenly over a 1 hour period, and the batch is mixed an additional 30 minutes.
The resulting product contained about 81% epoxy resin and 19% acrylic resin, by weight, with an equivalent ratio of acid polymer/amine/epoxy of about 2.5/1.8/1. X was 3, and Y was 22.5.
EXAMPLE 3
Into a suitably equipped kettle, inerted with nitrogen, are added the following parts by weight:
Monobutyl Ether of Ethylene Glycol: 91.567
Normal Butanol: 32.503
Ethyl Acrylate: 14.453
Tertiary Butyl Perbenzoate: 0.026
In a separate vessel, the following are added and mixed:
Ethyl Acrylate: 54.764
Methacrylic Acid: 122.060
Styrene: 72.919
Normal Butanol: 2.050
Tertiary Butyl Perbenzoate: 2.351
The reactor is heated to reflux and the monomer mixture is added evenly to the refluxing reactor over a two-hour period. Then 7.932 parts of monobutyl ether of ethylene glycol are added as a rinse for monomer feed lines. Reflux is maintained for one hour, at which point 55.500 parts of normal butanol is added. Reflux temperatures are maintained for an additional hour at which point the heat is turned off and 72.623 parts of normal butanol are added, followed by 82.312 parts of dimethyl ethanol amine and 246.940 parts of deionized water. The product is a solution of a styrene/ethyl acrylate/methacrylic acid//27.6/26.2/46.2 polymer at 30.8% solids in solvent, water and amine. The acid number of the product is 300.
Into a suitably equipped kettle, inerted with nitrogen, are added the following parts by weight:
Monobutyl Ether of Ethylene Glycol: 8.400
"Epon 829": 86.978
Bisphenol A: 46.835
The kettle charge is heated to 130°-140° C., heat removed and allowed to exotherm to 175°-200° C. After the exotherm is exhausted, heat is applied and the reaction mass is maintained above 165° C. for two hours after peak exotherm. At this point, a sample can be removed for determination of completion of reaction. Theoretical epoxy equivalent weight is 3000. 6.655 Parts of monobutyl ether of ethylene glycol and 27.366 parts of normal butanol are added to dilute the reaction mass and cool it to 100° C.
121.131 Parts of the neutralized acrylic polymer prepared in (A) are added rapidly following by 23.181 parts of deionized water. The mass is heated to reflux temperature and held for twenty-five minutes. Heat is turned off and 288.155 parts of deionized water, preheated to 70°-80° C. is added evenly over a one-hour period. This dispersion may be isolated here at 28% solids. It may also be further diluted to 20% solids with 220.159 parts of deionized water and 23.288 parts of normal butanol to provide a ready-to-spray product at water/organic solvent of 80/20 by volume.
The resulting product contained about 77.8% epoxy resin and 22.2% acrylic resin, by weight, with an equivalent ratio of acid polymer/amine/epoxy of about 4.6/3.0/1.0. X was 3, and Y was 51.5.
EXAMPLE 4
Add to 100 grams of Example 3(B) 5.6 grams Cymel 373, partially alkylated melamine formaldehyde resin which is 85% solids in water plus 14.2 water and 3.1 grams normal butanol. This acts as an external crosslinker to aid in curing coated films.
COMPARATIVE TEST 1
Certain tests were performed to determine the relative merits of water-borne coating compositions of the invention with the minimum claimed level of an acid number of 100 and epoxy content of 50% versus comparable compositions outside the invention with an acid number of 65 and an epoxy content of 40%. Minor adjustments had to be made in the equivalent ratios of acid polymer/amine/epoxy in order to accommodate the difference in acid number and epoxy content.
(A)
Compositions of the invention were represented by the reaction product of 50% of an acid polymer with an acid number of 100 made of
styrene: 42.4
ethyl acrylate: 42.3
methacrylic acid: 15.3
and 50% of "Epon 1007" epoxy resin with an average epoxy equivalent weight of about 2175, analyzed at 2368. The acid polymer has been neutralized with enough dimethyl ethanol amine to give theoretical equivalent ratios of acid polymer/amine/epoxy of 3.87/3.87/1 and actual analyzed ratios of 4.21/4.21/1. X was 2.175; Y was 66.1.
(B)
Compositions outside the invention were represented by the reaction product of 60% of an acid polymer with an acid number of 65 made of
styrene: 45
ethyl acrylate: 45
methacrylic acid: 10
and 40% of "Epon 1007" epoxy resin. The reaction product was made in the same manner as in (A) above with enough dimethyl ethanol amine to give theoretical equivalent ratios of acid polymer/amine/epoxy of 3.79/3.79/1 and actual analyzed ratios of 4.13/4.13/1. X was 2.175, and Y was 51.1.
The compositions of (B) were significantly less stable than those of (A). (B) separated by settling in 2-3 weeks under ordinary laboratory conditions, while (A) remained well dispersed. Although (B) could be redispersed by stirring, this settling would be expected to be more severe under stress conditions such as freezing and thawing. Such a lack of stability undesirable and probably commercially unacceptable when a stable product is available.
COMPARATIVE TEST 2
By empirically testing a large number of different compositions, it has been determined that a relationship exists between the epoxy equivalent weight and the milliequivalents (MEQ) of amine-neutralized carboxylic acid polymer for obtaining a stable dispersion. This relationship is expressed by a curve wherein Y is 6+0.75(2 X ), wherein Y is the milliequivalent of carboxyl groups neutralized with primary, secondary or tertiary amine or monofunctional quaternary ammonium hydroxide per 100 grams of acid polymer plus epoxy, and X is the epoxy equivalent weight divided by 1000. The curve represents the approximate locus of borderline stability. Above the curve, the compositions are stable if the other conditions of the invention are met including the acid number and the epoxy equivalent weight; below the curve, they are not. Although there is some flexibility in the precise location of the curve, it lies approximately where this definition puts it.
Data points of borderline stability have been determined as follows:
______________________________________X Y______________________________________0 63/41 71/22 93 124 18______________________________________
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Water-borne reaction products of (a) carboxyl-functional polymers; (b) polyepoxides; and (c) tertiary amines are useful as film-forming components of coating compositions which can be spray-, flow-, dip-, roller-, or electro-coated. The coating compositions are useful as such or can be crosslinked with crosslinking agents such as a nitrogen resin and, when coated on metal and paper substrates, they provide coatings of improved properties, including a high degree of flexibility during machining and stamping of the coated articles, corrosion resistance, gloss, hydrolytic stability, and nonadulterating of foods and beverages in contact therewith.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. §119(c) of U.S. Provisional Patent Application No. 61/321,740 filed Apr. 7, 2010, which application is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates generally to compounds, compositions and methods for prevention or treatment of HIV infection. More specifically, the present invention relates to glycomimetic compounds that inhibit HIV infection, and uses thereof.
[0004] 2. Description of the Related Art
[0005] Acquired Immune Deficiency Syndrome (“AIDS”), a fatal human disease, is generally considered to be one of the more significant diseases to affect humankind, and has affected numerous individuals worldwide. The disease appears to have originated in Africa and then spread to other locations, such as Europe, Haiti and the United States. AIDS began to be recognized as a distinct new disease in about the mid-1970s.
[0006] Due to the devastating effect of AIDS on patients and indications that the disease was spreading, much effort has been devoted to elucidate and identify the cause of the disease. Epidemiological data suggested that AIDS is caused by an infectious agent that is transmitted by exposure to blood or blood products. Groups reported to be at greatest risk of contracting AIDS include homosexual or bisexual males and intravenous drug users. Hemophiliacs who receive blood products pooled from donors and recipients of multiple blood transfusions are also at risk.
[0007] AIDS is a disease that damages the body's immune system, leaving victims susceptible to opportunistic infections, malignancies or other pathological conditions against which a normal immune system would have protected the subject. Clinical manifestations of the disease in its final stage include a collapse of a patient's immune defenses (which generally involves a depletion of helper T cells) accompanied by the appearance of a Kaposi sarcoma and/or various opportunistic infections. The pronounced depression of cellular immunity that occurs in patients with AIDS and the quantitative modifications of subpopulations of their T lymphocytes suggests that T cells or a subset of T cells are a central target for the infectious agent.
[0008] The etiology of AIDS and related disorders has been identified as being associated with infection by a class of lymphotrophic retrovirus termed human immunodeficiency virus (HIV; known previously as HTLV or LAV). The virus is spread when body fluids, such as semen, vaginal fluids or blood, from an infected individual are passed to an uninfected person. As noted above, AIDS is characterized by a disorder associated with an impaired cell-mediated immunity and lymphopenia, in particular, depletion of those T ceils that express the T4 (CD4) glycoprotein. This is due to the fact that HIV preferentially infects the CD4 lymphocyte population (CD4 cells). Both the binding of virus to susceptible target cells and the cell fusion that is a characteristic manifestation of HIV-induced cytopathology involve specific interactions between glycoproteins in the viral envelope and the cell surface of CD4 cells.
[0009] HIV contains two heavily glycosylated external envelope proteins. gp120and gp41, which mediate attachment of virions to glycosylated cell surface receptor molecules. These glycoproteins are encoded by the env gene and translated as a precursor, gp160, which is subsequently cleaved into gp120 and gp41. Gp120 binds to the CD4protein present on the surface of helper T lymphocytes, macrophages, and other cells, thus determining the tissue selectivity of viral infection.
[0010] The CD4 protein is a glycoprotein of approximately 60,000 molecular weight and is expressed on the cell membrane of mature, thymus-derived (T) lymphocytes, and to a lesser extent on cells of the monocyte-macrophage lineage. CD4 cells appear normally to function by providing an activating signal to B cells, by inducing T lymphocytes bearing the reciprocal CD8 marker to become cytotoxic/suppressor cells. and/or by interacting with targets bearing major histocompatibility complex (MHC) class II molecules. The CD4 glycoprotein in addition to playing an important role in mediating cellular immunity also serves as the receptor for HIV.
[0011] Other HIV has infected a cell, it replicates to increase the number of copies of the virus. Replication of the HIV genome proceeds by a series of enzymatic reactions involving two virus-encoded enzymes, reverse transcriptase (“HIV RT”) and integrase, as well as host cell-encoded DNA polymerases and RNA polymerase. HIV RT polymerizes deoxyribonucleotides by using viral RNA as a template and also acts as a DNA polymerase by using the newly synthesized minus strand DNA as a template to produce a double-stranded DNA. More specifically, HIV RT copies the viral RNA to yield an RNA-DNA hybrid. The RNA strand of the hybrid is degraded and then the viral polymerase copies the resultant single-stranded DNA to yield a double-stranded DNA. The latter is integrated into the host cell genome.
[0012] Due to the essential role of HIV RT in the invasion of a host organism by the virus, therapeutic approaches have been based upon an attempt to inhibit HIV RT or to incorporate nucleoside analogs that terminate viral DNA synthesis. The most commonly-used drugs against HIV RT are chain terminators. These molecules are presumably incorporated into the polynucleotide chain by HIV RT, but are unable to be extended on subsequent nucleotide additional steps. For example, azidothymidine (“AZT”), one of the most commonly used drugs for the treatment of AIDS, is directed against HIV RT. However, even these inhibitors of HIV RT have been limited in success because of the extensive genetic variation and high mutation rate of HIV. Therefore, by rapid evolution of HIV, mutations in HIV RT arise frequently in infected individuals and render the virus resistant to HIV RT inhibitors. This is a significant drawback to conventional therapies.
[0013] Although a few drugs such as AZT have prolonged the lives of some individuals with AIDS, there is presently no cure for AIDS. Therapeutic agents are needed for all stages of AIDS infectious. Due to the limited success for previously suggested compositions tor the treatment of AIDs, there is a need in the art for new therapies. The present invention fills this need, and further provides other related advantages. BRIEF SUMMARY
[0014] Briefly stated, compounds, compositions and methods tor preventing or treating HIV infection are provided.
[0015] The present invention in an embodiment provides a compound for inhibiting HIV infection, where the compound consists of a naphthalene, a phenalene, an anthracene, a phenanthrene or an acenaphthylene, joined to at least two glycomimetics selected independency from glycomimetics having the formula:
[0000]
[0000] wherein:
[0016] n=independently selected from 0-1;
[0000]
[0017] Y=C or O;
[0018] R 1 =independently selected from H, C(═0)OCH, L, with the provisos where there are two R i on the same glycomimetic that both R i are not H or U and where Y is O that there us no R 1 at Y;
[0000] R 2 =independently selected from H, C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyL halogenated C 1 -C 8 alkanyl, aryl or heterocycle either of which may be substituted with one or more of Me, OMe, halide, OH, or NHX where X=H, C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyl, halogenated C 1 -C 8 alkanyl, aryl or heterocycle cither of which may be substituted with one or more of Me, OMe, halide, or OH; —C(═ 0 )OX where X is C 1 -C 8 alkanyl, C 2 C 8 alkenyl, C 2 -C 8 alkynyl, aryl or heterocycle either of which may be substituted with one or more of Me, OMe, halide, or OH; —C(═O)NH(CH 2 ) n NH 2 where n=0-30, C(═0)NHX or CX 2 OH, where X=C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyL halogenated C 1 -C 8 alkanyl, aryl or heterocycle either of which may be substituted with one or more of Me, OMc, halide, or OH; OC(═O)X, OX, NHX, NH(═ 0 )X, where X=H, C 1 -C 3 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyl, halogenated C 1 -C 8 alkanyl, aryl or heterocycle either of which may be substituted with, one or more of Me, OMe, halide, or OH;
[0000]
[0000] where R 9 =F, NH 2 , C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, aryl, COOH, or COOR 10 , R 10 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl, R 11 =C 1 -C 8 alkanyl, C 2 -C 8 alkcnyl, or C(═O)R 12 , R 12 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl;
R 3 =H, mannose;
R 5 =H, C 1 -C 8 alkanyl,aryl,
[0000]
[0000] where R 9 =F, NH 2 , C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, aryl, COOH, or COOR 10 , R 10 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl, R 11 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, Or C( O)R 12 , R 12 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl;
R 6 =H, C 1 -C 8 alkanyl, aryl, CH 2 OH,
[0000]
[0000] where R 9 =F, NH 2 , C 1 -C 8 alkanyl, C 2 -C 8 alkenyl aryl, COOH or COOR 10 , R 10 - 32 C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl, R 11 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or C(═O)R 12 , R 12 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl;
[0019] R 7 =H,OH;
[0020] R 8 =H, OH, CH 3 , —(CH 2 ) m CH 3 where m=1-20; and
[0021] L is a linker to which the glycomimetic is covalently joined to the naphthalene, phenalene, anthracene, phenanthrene, or acenaphthytene.
[0022] A compound of the present invention may be covalcntly joined (linked) to a vaccine carrier.
[0023] Compositions are formed by combining a compound of the present invention (with or without a vaccine carrier) with a pharmaceutically acceptable carrier or diluent.
[0024] The present invention provides a method for inhibiting HIV infection in an individual comprising administering to the individual in an amount effective to inhibit HIV infection a compound of the present invention, thereby inhibiting the HIV infection.
[0025] A compound or composition of the present invention can be used to develop therapeutic antibodies (e.g., monoclonal antibodies).
[0026] A compound or composition of the present invention can be used as an inhibitor of HIV infection or in the manufacture of a medicament, for example, for any of the uses recited herein.
[0027] These and other aspects of the present invention will become apparent upon reference to the following detailed description and attached drawings. All references disclosed herein are hereby incorporated by reference in their entirety as if each was incorporated individually. The chemical formulae set forth herein are depicted without regard to axial or equatorial forms or projections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 ( Fig. 1A , Fig. 1B and Fig. 1C ) is a diagram illustrating the synthesis of a glycomimetic.
[0029] Figure 2 is a diagram illustrating the synthesis of a compound of the present invention,
DETAILED DESCRIPTION
[0030] As noted above, the present invention provides compounds, compositions and methods for use in preventing (prophylaxis) or treating HIV infection. The compounds have a variety of uses in vitro and in vivo, including for use to inhibit HIV infection. A compound of the present invention may comprise, or consist of, the compounds disclosed herein, a portion of which, may include any of the formulae depicted herein. The compounds include, or consist of, a naphthalene, phenalene, anthracene, phenanthrene or acenaphthylene, to which is covaicntfy joined at least two (i.e, two or more up to ten including any whole integer in-between) glycomimetics. The glycomimetics are independently selected, i.e., the glycomimetics may be the same or different. Where there are more than two glycomimetics in a compound, it is possible to also have some, but not all, of the glycomimetics the same in the compound.
[0031] All compounds of the present invention or useful thereto (e.g., for pharmaceutical compositions or methods of preventing or treating) include physiologically acceptable salts thereof. Examples of such salts are Na, K, Li, Mg, Ca and CI.
[0032] In one embodiment, at least one of the glycomimetics of the compound has the formula:
[0000]
[0033] In another embodiment, at least one of the giyeomimetics of the compound has the formula:
[0000]
[0000] Y is either carbon or oxygen. In one embodiment, Y is carbon.
[0034] The glycomimctics of the above formulae may possess a variety of substiruents via the R. groups, and n (which may be 0 or 1) is independently selected for (X) n and (Z) n . Thus, each glycomimetic of the compounds may possess no X and Z; no X and one Z; one X and DO Z; or one X and one X.
[0035] Where n is 0 for (X) n , there is no X present. Where n is 1 for (X) n , X is present. X is
[0000]
[0036] Where n is 0 for (Z) n , there is no Z present and the glycomimetics of the compounds have the formulae:
[0000]
[0037] In these glycomimetics, there is no X where this n is 0, or X (as set forth above) is present where this n in 1.
[0038] Where n is 1 for (Z) n , Z is present. Z is
[0000]
[0039] With X present, the glyeonrioiettcs of the eoropoun&s have the formulae:
[0000]
[0040] In these glycomiraclics, there is no X where this n is 0, or X (as set forth above) is present where this n is 1. Z possesses R 1 , R 5 , R 6 and R 7 . R 4 is a ring atom and may be either oxygen (O) or carbon (C). R 5 is H, C 1 -C 8 alkanyl, aryl,
[0000]
[0000] where R 9 =F,
NH 2 , C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, aryl, COOH, or COOR 10 , R 10 =C 1 -C 8 alkanyl, C 1 -C 8 alkenyl, or aryl, R 11 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or C(═O)R 12 , R 12 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyL or aryl. R 6 is H, C 1 -C 8 alkanyl, aryl, CH 2 OH,
[0000]
[0000] where R 9 =NH 2 , C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, aryl, COOH, or COOR 10 , R 10 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl, R 11 -C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or C(═O)R 12 , R 12 -C 1-C 8 alkanyl, C 2 -C 8 alkenyl, or aryl. R 7 is H or OH.
[0041] Other substiltients common to the above formulae are R 1 , R 2 and R 3 . R 1 is independently selected from H, C(═O)OCH 3 or L, with the proviso that both R 1 are not H or L (i.e., where there are two R 1 present on the same glycomimetic, the two R 1 are not both H and the two R 1 are not both L), and with the proviso where Y is oxygen that there is no R 1 at Y. R 2 is independently selected from H, C 1 -C 8 alkanyl, C 2 C 8 alkenyl, C 2 -C 8 alkynyl, halogenated C 1 -C 8 alkanyl, aryl or heteroeycle cither of which may be substituted with one or more of Me, OMe, halide, OH, or NHX where X=H, C 1 -C 8 alkanyl, C 2 -C 8 alkenyl C 2 -C 8 alkynyl, halogenated C 1 -C 8 alkanyl, aryl or heteroeycle either of which may be substituted with one or more of Me, OMe, haiide, or OH; —C(═O)OX where X is C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyl, aryl or heterocyclc either of which may be substituted with one or more of Me, OMe, halide, or OH; —C(═O)NH(CH 2 ) n NH 2 where n=0-30, C(═O)NHX or CX 2 OH, where X=C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyl, halogenated C 1 -C 8 alkanyl, aryl or heteroeycle cither of which may be substituted with one or more of Me, OMe, halide, or OH; OC(═O)X, OX, NHX, NH(═O)X, where X=H, C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyl, halogenated C 1 -C 8 alkanyl, aryl or heteroeycle either of which may be substituted with one or more of Me, OMe, halide, or OH;
[0000]
[0000] where R 9 =F, NH 2 , C 1 -C 8 alkanyl, G 2 -G 8 alkenyl, aryl, COOH, or COOR 10 , R 10 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl, R 11 =C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or C(═O)R 12 , R=C 1 -C 8 alkanyl, C 2 -C 8 alkenyl, or aryl. An example of Ra has the formula:
[0000]
[0000] R 3 is H or mannose.
[0042] R 8 is specific to certain compound embodiments. R 8 is H, OH, CH 3 , —(CH 2 ) m CH 3 where m is 1-20.
[0043] Where L is present, it is a linker. A linker may be biologically active or inactive. In one embodiment, the linker is biologically inactive. A linker may be (or may include) a spacer group, such as —(CH 2 ) p — or —O(CH 2 ) p —where p is generally about 1-20 (including any whole integer range therein). Other examples of spacer groups include a carbonyl or carbonyl containing group such as an amide. An embodiment of such spacer group is
[0000]
[0044] Emodiments of linkers include the following:
[0000]
[0045] Other linkers, e.g, polyethylene glycols (PEG) or —C(═O)—NH (CH 2 ) p —C(═O)—NH 2 where p is as denned above, will be familiar to those in the art or in possession or the present disclosure.
[0046] In another embodiment, the linker is
[0000]
[0047] In another embodiment the linker is
[0000]
[0048] In another embodiment, the linker is —CH(═O)—NH—(CH 2 ) 2 —NH—.
[0049] In another embodiment, the linker is —CH 2 —NH—CH 2 —.
[0050] In another embodiment, the linker is —C(═O)—NH—CH 2 —.
[0051] As used herein, a “C 1 -C 8 alkanyl” refers to an alkane substituent with one to eight carbon atoms and may be straight chain, branched or cyclic (cycloalkanyl). Examples are methyl (“Me”), ethyl, propyl, isopropyl, butyl and t-butyl. A “halogenated C 1 -C 8 alkany” refers to a “C 1 -C 8 alkanyl” possessing at least one halogen. Where there is more than one halogen present, the halogens present may be the same or different or both (if at least three present). A “C 2 -C 8 alkenyl” refers to an aikene substituent with two to eight carbon atoms, at least one carbon carbon double bond, and may be straight chain, branched or cyclic (cycloalkenyl). Examples are similar to “C 1 -C 8 alkanyl” examples except possessing at least one carbon carbon double bond. A “C 2 -C 8 alkynyl” refers to an alkyne substituent with two to eight carbon atoms, at least one carbon-carbon triple bond, and may be straight chain, branched or cyclic (cycloalkynyl). Examples are similar to “C 1 -C 8 alkaynly” examples except possessing at feast one carbon carbon triple bond. An “alkoxy” refers to an oxygen substituent possessing a “C 1 -C 8 alkanyl,” “C 2 -C 8 alkenyl” or “C 2 -C 8 alkynyl.” This is —O-alkyl; for example methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy and the like; and alkenyi or alkynyl variations thereof (except for mcthoxy). It further refers to the group O-alkyl-W-alkyl where W is O or N; for example —O—(CH 2 ) n—W—(CH 2 ) m where n and m are independently 1-10. An “aryl” refers to an aromatic substituent with five to fourteen carbon atoms as ring atoms in one or multiple rings which may be separated by a bond or fused. As used herein, “heterocycle” includes aromatic and nonaromatic subsiituents. A “heterocycle” is a ringed substituent (one or multiple rings) that possesses at least one licteroutom (such as N, O or S) in place of a ring carbon. There are typically three to fourteen ring atoms. Examples of aryls and heterocycies include phenyl, naphthyl, pyridinyl, pyrimidinyl, triazolo, furanyl, oxazolyl, thiophenyl, quinolnyl and diphenyl.
[0052] At least two glycomimetics are joined to a “naphthalene” (i.e., unsubstituted naphthalene or substituted naphthalene), an “anthracene” (i.e., unsubstituted anthracene or substituted anthracene), a “phenalene” (i.e., unsubstituted phenalene or substituted phenalene), an “acenaphthylene” (i.e.. unsubstituted acenaphthylene or substituted acenaphthylene), or a “phenanthrene” (i.e., unsubstituted phenanthrene or substituted phenanthrene). Examples of substituents include C 1 -C 8 alkanyl, halogenated C 1 -C 8 alkanyl, alkoxy and halogens. Unsubstituted naphthalene
[0000]
[0000] is which at least two linkers are attached, Unsubstituted anthracene is
[0000]
[0000] to which at least two linkers are attached. Unsubstituted
phenlene is
[0000]
[0000] to which at least two linkers are attached.
[0000]
[0000] Unsubstituted accnaphthylene is
[0000]
[0000] to which at least two linkers are attached. Unsubstituted phenanthrene is to which at least two linkers are attached. Examples of naphthalene or phenalene include:
[0000]
[0053] R 13 is NH or L. R 13 is used to attach to a glycomimetic. R 14 is H, CHO, L or L.A. L is a linker. L of R 14 is the same or different than L of R 13 . A is a vaccine carrier. Examples of a vaccine carrier include tetanus toxoid, keyhole limpet hemocyanin (KLH) or other protein carriers.
[0054] Compounds as described herein may be present within a pharmaceutical composition. A pharmaceutical composition comprises one or more compounds in combination with (i.e., not covalently bonded to) one or more pharmaceutically or physiologically acceptable carriers, diluents or excipients. Such compositions may comprise buffers (e.g., neutral buffered saline or phosphate buffered saline), carbohydrates (e.g., glucose, mannose, sucrose or dextrans), mannitol, proteins, polypeptides or amino acids such as glycine, antioxidants, chelating agents such as EDTA or glutathione, adjuvants (e.g., aluminum hydroxide) or preservatives. Within yet other embodiments, compositions of the present invention may be formulated as a lyophilizate. Compositions of the present invention may be formulated for any appropriate manner of administration, including for example, topical, oral, nasal, intravenous, intracranial, intraperitoneal, subcutaneous, or intramuscular administration.
[0055] The compositions described herein may be administered as part of a sustained release formulation (i.e., a formulation such as a capsule or sponge that effects a slow release of compound following administration). Such formulations may generally be prepared using wolf known technology and administered by, for example, oral, rectal or subcutaneous implantation, or by implantation at the desired target site. Carriers for use within such formulations are biocompatible, and may also be biodegradable; preferably the formulation provides a relatively constant level of compound release. The amount of compound contained within a sustained release formulation depends upon the site of implantation, the rate and expected duration of release and the nature of the condition to be treated or prevented.
[0056] The above-described compounds including equivalents thereof are useful in methods of the present invention. In one embodiment, one or more of the compounds may be used in a method for inhibiting HIV infection in an individual. The individual may already have been exposed to HIV or may be at risk of such an exposure. Accordingly, the method may be for treating HIV infection or for preventing (prophylaxis) HIV infection. The method comprises administering in an amount effective to inhibit HIV infection a compound described herein. The compound may be with a pharmaceutically acceptable carrier or diluent.
[0057] The above-described compounds may be administered in a manner appropriate to the individual to be treated. Appropriate dosages and a suitable duration and frequency of administration may be determined by such factors as the condition of the patient, the type and severity of the patient's disease and the method of administration. In general, an appropriate dosage and treatment regimen provides the comnound(s) in an amount sufficient to provide therapeutic or prophylactic benefit. Within particularly preferred embodiments of the invention, a compound may be administered at a dosage ranging from 0.001 to 1000 mg/kg body weight (more typically 0.01 to 1000 mg/kg), on a regimen of single or multiple daily doses. Appropriate dosages may generally be determined using experimental models or clinical trials. In general, the use of the minimum dosage that is sufficient to provide effective therapy is preferred. Patients may generally be monitored for therapeutic effectiveness using assays suitable for the condition being treated, which will be familiar to those of ordinary skill in the art.
[0058] A compound or composition of the present invention can be used to develop therapeutic antibodies. Methods for producing therapeutic antibodies are well known in the art. The antibodies may be monoclonal antibodies. In an embodiment, the therapeutic antibodies may have been modified by domain swapping. Such methods are well known m the art. The therapeutic antibodies may be administered to an individual who already has been exposed to HIV or to an individual who may be at risk of such an exposure. Appropriate dosages and a suitable duration and frequency of administration may be determined by such factors as the condition of the patient, the type and severity of the patient's disease and ihe method of administration. In general, an appropriate dosage and treatment regimen provides the antibodies in an amount sufficient to provide therapeutic or prophylactic benefit. Appropriate dosages may generally be determined using experimental models or clinical trials. In general, the use of the minimum dosage that is sufficient to provide effective therapy is preferred. Patients may generally be monitored for therapeutic effectiveness using assays suitable for the condition being treated, which will be familiar to those of ordinary skill in the art.
[0059] A compound or composition of the present invention can be used as an inhibitor of HIV infection or in the manufacture of a medicament, for example for any of the uses recited herein. A medicament may include more than one compound or composition of the present invention. A medicament may include any compounds or compositions known at the time of ihe preparation of the medicament (e.g., one or more compounds useful in the prevention or treatment of HIV).
[0060] At least one (i.e., one or more) of the above described compounds may be administered in combination with at least one (i.e., one or more) anti-HIV agent. The compound may function independent of the agent, or may function in coordination with the agent, e.g., by enhancing effectiveness of the agent or vice versa. In addition, the administration may be in conjunction with one or more other therapies for reducing toxicities of therapy. For example, at least one (i.e., one or more) agent to counteract (at least in part) a side effect of therapy (e.g., anti-HIV therapy) may be administered. Agents (chemical or biological) that promote recovery are examples of such agents. At least one compound described herein may be administered before, after or simultaneous with administration of at least one agent or at least one agent to reduce a side effect of therapy. Where administration is simultaneous, the combination may be administered from a single container or two for more) separate containers.
[0061] The following Examples are offered by way of illustration and not by way of limitation.
EXAMPLES
Example 1
Synthesis of A Representative Glycomimetic (Compound 19 ; FIG. 1 )
A. Synthesis of Compound 12 (FIG. 1A)
[0062] Synthesis of compound 3: Compound 3 (25 g) is synthesized as described in the literature (Carbohydr. Res. 193 (1989) 283-287).
[0063] Synthesis of compound 4: Compound 3 (20g) is stirred with 0.025 M NaOMc in MeOH (200 ml) for 4 h at room temperature. Neutralized with IR-120 (H+) resin, filtered and the liquid is evaporated to dryness to give compound 4 (12 g).
[0064] Synthesis of compound 3: Compound 4 (11.8 g) is co-evaporated with toluene (3×50 ml). The residue is dissolved in diy DMF (125 ml), and α,α-dimethoxy propane (60 ml) is added, followed by p-tohiene-sulfonic acid (0.125 g) with stirring at room temperature. Stirring is continued for 2 days at room temperature, neutralized with triethylamine (0.2 ml) and evaporated to dryness. The residue is dissolved in CH 2 Cl 2 (70 ml) and washed with H 2 O (3×50 ml). Organic layer is dried over Na 2 SO 4 filtered and concentrated to dryness. The residue is crystallized from hcxanes to give compound 5 (12 g).
[0065] Synthesis of compound 6: Compound 5 (11 g) is dissolved in acetone (160 ml), water (8 ml) and p-toluene-sulfonic acid monohydrate (0.8 g) is added with stirring at 40° C. The reaction mixture is stirred at 40° C. for 15 min. Triethylamine (1 ml) and NaHCO 3 (2 g) is added with stirring. The solution is then concentrated to dryness. Water (25 ml) is added and then extracted with hcxanes (2×75 ml). Aqueous layer is then extracted with CH 2 Cl 2 (4×80 ml). Organic layer is dried (Na 2 SO 4 ), filtered and evaporated to dryness. The residue ts crystallized from EtOAc-hexancs to give compound 6 (6 g),
[0066] Synthesis of compound 7: Compound 6 (5.5 g) is dissolved in DMF (40 ml) and cooled to 0° C. NaH (2.5 g, 60% dispersion in oil) is added with stirring. After 15 min, C 6 H 5 CH 2 Br (7.7 ml) is added with stirring in the cold. Ice-bath is removed and the stirring is continued for 7 h at room temperature, followed by addition MeOH (5 ml) with Stirring at room temperature. The reaction mixture is concentrated to dryness, residue is dissolved in. CH 2 Cl 2 (100 ml) and washed successively with brine, 1 N HCI and brine. Organic layer is concentrated to dryness to give crude compound 7. It is used in the next step without further purification.
[0067] Synthesis of compound 8: Compound 7 (12 g crude) is dissolved in AcOH (20 ml), and water (5 ml) is added with stirring at 70° C. Stirring is continued for 1 h at 70° C., solvent is evaporated off and the residue is crystallized from EiOAc-hexanes to compound 8 (5.2 g).
[0068] Synthesis of compound 9: Compound 8 (5 g) is dissolved in CH 2 Cl 2 (200 ml). Allyl bromide (1.2 ml), Bu 4 NBr (1.2 g) and 5% aqueous NaOH solution (20 ml) is added with Stirring. The reaction mixture is vigorously stirred at room temperature for 2 days. Organic layer is washed with H 2 0 (4×150 ml), dried (Na 2 SO 4 ) and concentrated to dryness. The residue is purified by column chromatography (silica gel) to give compound 9 (4.5 g).
[0069] Synthesis of compound 10: Compound 9 (4 g) is dissolved in DMF (30 ml) and cooled to 0° C. NaH (0.64 g, 60% dispersion in oil) is added with stirring. After 15 min, C 6 H 5 CH 2 Br (2.8 ml) is added vvith stirring in the cold. Ice-bath is removed and the stirring is continued for 7h at room temperature followed by addition MeOH (5 ml) with stirring at room temperature. The reaction mixture is concentrated to dryness, residue is dissolved in CH 2 Cl 2 (100 ml) and washed successively with brine, 1 N HCl and brine. Organic layer is concentrated to dryness and purified by column chromatography (silica gel) to give compound 10 (4.2 g).
[0070] Synthesis of compound 11: To a solution of compound 10 (4 g) in dry DMSO (20 ml) is added potassium tert-butoxide (0.5 g) and the reaction mixture is stirred, at 100° C. for 2h under dry nitrogen. The reaction mixture is cooled down to room temperature and H 2 ) (40 ml) is added with stirring. The reaction mixture is extracted with CH 2 Cl 2 (4×50 ml). The organic layer is washed with H 2 O (3×40 ml) and concentrated to dryness. The residue is dissolved in CH 3 COCH 3 —H 2 O (10:1, 33 ml), yellow mercuric oxide ( 2 g) is added with stirring and then a solution of HgCl 2 (2 g) in CH 3 COCH 3 —H 2 O (10:1, 20 ml) is added dropwise with stirring at room temperature. After 30 min, the reaction mixture is filtered through Celite and concentrated to dryness. Diethylether (100 ml) is added and the solution is washed vv ith a saturated solution of KI (1×50 ml) and water (2×50 ml). The organic layer is concentrated to dryness and purified by column chromatography (silica gel) to give compound 11 (2.2 g).
[0071] Synthesis of compound 12: A mixture of compound 11 (2 g), compound 3 (2.4 g), and activated powdered molecular sieves (4Å, 2 g) in dry CH 2 Cl 2 (50 ml) is stirred at room temperature for 1h under argon. The mixture is cooled to 0-5° C. (ice-bath) and NIS (2.2 g) is added while stirring in the cold. A 0.15 M solution of trillic acid in CH 2 Cl 2 (10 ml) is added dropwise over 30 min with stirring in the cold. After 1h, the reaction mixture is filtered through Celite and washed successively with cold 5% aqueous solution of Na 2 S 2 O 3 , saturated solution of NaHCO 3 , and H 2 O. The organic layer is concentrated to dryness and purified by column chromatography (silica gel) to give compound 12 (2.7 g).
B. Synthesis of Compound 13 (FIG. 1B)
[0072] Synthesis of compound II: Commercially available cis-1,2,3,4-tetrahydrophthalic anhydride (I, 50 g) is added to a suspension of amberlyste 35 (50 g, dried under vacuum) in methanol (1L) with stirring. Triethylorthoformate (100 ml) is added immediately while stirring. The reaction mixture is then vigorously stirred for 5 days at room temperature and additional triclhylorthoformate is added. Stirring is continued for an additional 4 days, filtered over celite and washed with methanol. The solvent is removed in vacuum and the residue is dissolved in CH 2 Cl 2 (200 ml). The solution is washed with cold saturated solution of NaHCO 3 (200 ml) and cold brine (200 ml). The organic layer is dried (Na 2 SO 4 ), filtered and concentrated to dryness to afford compound II (55 g).
[0073] Synthesis of compound III: To a suspension of compound II (10 g) in phosphate buffer (400 ml, pH 7) is added PLE (40 mg, 1080 unit). The pH of the mixture is maintained at 7 by continuous drop wise addition of 1M NaOH solution via syringe pump. The reaction is stirred at 20° C. until 1 equivalent of NaOH (50 ml) is used. The reaction mixture is transferred to a seperatory funnel and EtOAc (400 ml) is added. The layers are separated and the organic layer extracted with phosphate buffer (2×250 ml, pH 7). The combined aqueous layers are acidified (pH 2) with aqueous HCl (1M) and extracted with EtOAc (3×400 ml). The combined organic layers are dried (Na 2 SO 4 ). filtered and concentrated to dryness to afford compound III (7.8 g).
[0074] Synthesis of compound IV: To a solution of compound III (2 g) in dry CH 2 Cl 2 (35 ml) is added (COCl); (1.4 ml) and DMF (0.025 ml) and stirred for 3h at RT. The solution is evaporated to dryness (rotavapor is purged with argon). The residue is dissolved in dry THF (40 ml) and added dropwise over a period of 20 min to a boiling suspension of 2-mercaptopyridine-1-oxid sodium salt (2 g), t-BuSH (6 ml), and 4-DMAP (52 mg) in dry THF (100 ml). The solution is stirred under reflux for 3 h. The reaction mixture is cooled down to RT and transferred into a seperatory funnel with EtOAc (100 ml) and washed with H 2 O (100 ml). The aqueous layer is extracted with EtOAc (2×200 ml). The combined organic layers are dried (Na 2 S 4 ), filtered and concentrated to dryness. The crude product is purified by column chromatography (silica) to afford compound IV as yellowish oil (1.1 g).
[0075] Synthesis of compound V: To a suspension of compound IV (4 g) in phosphate buffer (400 ml, pH 7) is added PLE (42 mg) with stirring. The pH is kept at 7 by adding NaOH solution (1 M) via syringe pump. The reaction mixture is stirred at RT until 1 equivalent ofNaOH is used. The reaction mixture is transferred to a seperatory funnel and washed with EtOAc (2×250 ml). The layers are separated and the organic layers extracted with phosphate buffer ( 2 × 250 ml, pH 7). The combined aqueous layers are acidified to pH 2 with aqueous HCl solution and extracted with EtOAc (3×300 ml). The combined organic layers are dried (Na 2 SO 4 ), filtered and evaporated to dryness. The crude product is filtered through a short plug of silica to afford compound V (3 g).
[0076] Synthesis of compound VI: Compound V (4 g) is suspended in water (90 ml) and cooled down to 0° C. NaHCO3 (8 g) is added followed by a solution of Kl (32 g) and I 2 (8 g) in water (75 ml). The reaction mixture is stirred at RT for 24 h and then extracted with CH 2 Cl 2 (3×30 ml). The combined organic layers are washed with a saturated solution of Na 2 S 2 O 3 in water (125 ml). The aqueous layer is extracted with CH 2 Cl 2 (2×30 ml). The combined organic layers are protected from light, dried (Na 2 SO 4 ), filtered, and concentrated to dryness and quickly under high vacuum to afford iodolaetone VI as an off-white solid (7.5 g).
[0077] Synthesis of compound VII: Compound VI (7 g) is dissolved in dry THF (170 ml) and DBU (7 ml) is added. The reaction mixture is refluxed for 20 h and then cooled downed to RT. Diethyl ether ( 1 00 ml) is added and transferred into a separatory funnel and extracted with aqueous solution of HCI (200 ml, 0.5 M). The aqueous layers are extracted with Et 2 O (3×100 ml). The combined organic layers are washed with brine (200 ml), dried (Na 2 SO 4 ), filtered, and concentrated to dryness. The crude product is purified by column chromatography (silica gel) to afford compound VII (3.7 g).
[0078] Synthesis of compound VIII: NaHCO 3 (2.2 g) is dried under vacuum and then dry MeOH (132 ml) is added with stirring followed by compound VII (3 g). The reaction mixture is then stirred at RT under argon for 12 h. The solvent is evaporated off and the residue transferred into a sepcratory funnel with CH 2 Cl 2 (35 ml), extracted with water (40 ml) and with brine (40 ml). The aqueous layer is extracted with CH 2 Cl 2 (2×35 ml). The combined organic layers are dried (Na 2 SO 4 ), filtered, and concentrated to dryness to give compound VIII (5 g).
[0079] Synthesis of compound IX: To a solution of compound VIII (4 g) in dry CH 2 Cl 2 (80 ml) is added tert-butyidimethylsilyl chloride (7.2 ml) in small portions, followed by DBU (9.5 ml). The reaction mixture is stirred for 12 h and then quenched with MeOH (12 ml). The reaction mixture is transferred into a sepcratory funnel with CH 2 Cl 2 (60 ml), washed with cold saturated solution of NaHCO 3 (50 ml) and cold brine (50 ml). The aqueous layers are extracted with CH 2 Cl 2 (2×50 ml). The combined organic layers are dried (Na 2 SO 4 ), filtered and concentrated to dryness. The residue is purified by column chromatography (silica) to give compound IX (6 g).
[0080] Synthesis of compound X: To a cold (10° C.) solution of compound IX (5 g) in CH 2 Cl 2 (125 ml) is added m-CPBA (8 g) with stirring and continued to stir for 15 h at 10° C. The temperature is raised to RT over a period of 2 h and the mixture diluted with CH 2 Cl 2 (400 ml). The mixture is transferred into a sepcratory runnel, washed with a cold saturated solution ofNa 2 S 2 O 3 solution in water (2×400 ml). The organic layer is successively washed with cold saturated solution NaHCO 3 (400 ml) and cold brine (100 ml). The aqueous layers are extracted with CH 2 Cl 2 (2×400 ml). The combined organic layers are dried (Na 2 SO 4 ), filtered, and concentrated to dryness. The crude product is purified by column chromatography (silica) to give compound X (4 g).
[0081] Synthesis of compound 13: CuCN (1.5 g) is dried in high vacuum at 150° C. for 30 min, suspended in dry THF (25 ml) and cooled down to −78° C. MeLi (1.6 M in Et 2 O, 22.5 ml) is added slowly via syringe and the temperature raised to −10° C. over a period of 30 min. The mixture is again cooled down to −78° C. followed by the addition of BF 3 etherate (1.4 ml) in THF (5 ml). After stirring for 20 min. compound X (1 g) in THF (25 ml) is added and stirring continued for 5 h at −7° C. The excess of MeLi is quenched with mixture of MeOH (10 ml) and Et 3 N (10 ml). The mixture is diluted with Et 2 O (250 ml) and transferred into a sepcratory funnel and extracted with an aqueous 25% NH/ e /satd. NH 4 Cl (1:9) solution. The organic layer is successively washed with brine (150 ml), 5% AcOH (150 ml), saturated solution of NaHCO 3 (150 ml), and brine (150 ml). The aqueous layers are extracted with Et 2 O (2×250 ml). The combined organic layers are dried (Na 2 SO 4 ), filtered, and concentrated to dryness. The crude product is purified by column chromatography (silica) to give compound 13 (800 mg).
C. Synthesis of Compound 19 (FIG. 1C)
[0082] Synthesis of compound 14: To a solution of compound 13 (1 g) in CH 2 Cl 2 (25 ml) is added powdered molecular sieves (4Å, 1 g) and compound 12 (2.8 g). The reaction mixture is allowed to stir at room temperature for 2 h at under argon. Silver trifluoromethanesulfonate (1.5 g) is added, and stirring is continued for 15 min. then Br 2 (0.1 ml) is added and the reaction mixture is stirred for a further 2 h under argon. Triethylamine (0.5 ml) is added and the reaction mixture is filtered through a bed of Celite. CH 2 Cl 2 (100 ml) is added and the organic layer is successively washed with 5% Na 2 S 2 O 3 (50 ml), saturated solution of NaHCO 3 (50 ml), and H 2 O (50 ml). Organic layer is concentrated to dryness and the residue is purified by column chromatography (silica gel) to give compound 14 (2 g).
[0083] Synthesis of compound 15: To a solution of compound 14 (1.8 g) in THF (15 ml) is added a solution of ictrabutylammomum fluoride (9.6 ml) and the reaction mixture is stirred at room temperature tor 24 h. Solvent is evaporated off and the residue is purified by column chromatography (silica gel) to give compound 15 (1.5 g).
[0084] Synthesis of compound 16: To a solution of compound 15 (1.4 g) in CH 2 Cl 2 ( 15 ml) is added powdered molecular sieves (4Å, 0.5 g) and compound 12 (1.4 g). The reaction mixture is stirred at room temperature for 2 h under argon. Silver tirifluoromcethanesulfonate (0.8 g) is added, and stirring is continued for 15 min, then Br 2 (0.05 ml) is added and the reaction mixture is stirred for a further 2 h under argon. Triethylamine (0.25 ml) is added and the reaction mixture is filtered through a bed of Celiie. CH 2 Cl 2 (50 ml) is added and the organic layer is successively washed with 5% Na 2 S 2 O 3 (25 ml), saturated solution of NaHCO 3 (25 ml), and H 2 O (25 ml). Organic layer is concentrated to dryness and the residue is purified by column chromatography (silica gel) to give compound 16 (1.2 g).
[0085] Synthesis of compound 17: Compound 16 (1 g) is stirred with 0.025 M NaOMe in MeOH (10 ml) for 4 h at room temperature. Neutralized with IR-120 (H+) resin, filtered and the liquid is evaporated to dryness to give compound 17 (0.5 g).
[0086] Synthesis of compound 18: Compound 17 (0.45 g) is dissolved in McOH (5 ml) and 10% Pd-C (0.25 g) is added. The reaction mixture is shaken under hydrogen for 24 h at room temperature. The reaction mixture is filtered through Celite and the filtrate is evaporated to dryness to give compound 18 (0.25 g). Synthesis of compound 19: Compound 18 (0.2 g) is treated with ethylenediaminc (2 ml) at room temperature overnight, solvent is evaporated off and the residue is purified by sephadex G-10 column to give compound 19 (0.15 g).
Example 2
Synthesis of a Representative Compound (Compound 21; FIG. 2 )
[0087] Synthesis of compound 21: To a solution of commercially available compound 20 (12 mg, Aldrich chemical company, St. Louis, Mo.) in DMF (0.25 ml) is added N,N-Diisopropylethylamine (0.022 ml) and HATU ( 0 . 060 g) and stirred for 3 min at room temperature. To this reaction mixture is added compound 19 (0.1 g) from Example 1, and the reaction mixture is stirred for 30 min at room temperature. The reaction mixture is concentrated to dryness and the residue is first passed through a sep-pak C18 cartridges and then purified by reverse-phase hplc to give compound 21 (0.07 g).
EXAMPLE 3
DC-Sign Assay
[0088] 1. Coat probind 96-well microliter plate: DC-Sign (ECD)
a) Add DC-Sign (R&D Systems. Minneapolis, Minn.) 100 μl /well of 3 μg/ml to columns 1-11 b) Buffer only [Tris-Ca +2 ] to column 12
[0091] 2. Incubate: 2 hours at 37° C. covered
[0092] 3. Block: with BSA
a) Prepare 1% BSA b) Add 100 μ/well of 1% BSA in (Tris-Ca +2 )
[0095] 4 . Incubate: 2 hours at room temp, covered
[0096] 5. Prepare samples in separate round bottom plate: 1
a) Prepare compounds in (Tris-Ca +2 ) with 10% DMSO b) Add 120 μl of compounds to column 1, then 2X dilutions to columns 2-9 c) Buffer only [1% BSA in (Tris-Ca +2 )] to columns 10 & 12 60 μl, and to column 11 120 μl
[0100] 6. Add Le a -PAA-biotin/SA-HRP to round bottom plate
a) Le a -PAA (GlycoTech Corp., Rockville, Md.) is pre-incubated (24 hours) with sStreptavidin-labeled horseradish peroxidase (SA-HRP) to form Le a -PAA/SA-HRP polymer. b) Add 60 μl/well of 0.5 μg/ml Le a -PAA-biotin/SA-HRP polymer to columns 1-10 & 12.
[0103] 7. Wash probind plate: 4 times with Tris-Ca +2
[0104] 8 . Transfer samples: 100 μl/well from round bottom plale to probind plate
[0105] 9 . Incubate: 2 hours at room temp. covered and rotating
[0106] 10 . Wash probind plate: 4 times with Tris-Ca +2
[0107] 11. Add TMB (3,3′,5,5′-tetramethyl benzidine):H 2 O 2 : 100 μl/well
[0108] 12. Incubate: 3 min at room temp.
[0109] 13. Add H 3 PO 4 : 100 μl/well of 1M solution to H 3 PO 4 solution to stop reaction
[0110] 14. Plate reader: read at 450 nm
Example 4
Immunoassay to Determine the Binding of Glycomimetic Antigen for Antibody 2G12
[0111] 1. Coal wells of a 96 microtiter plate with gp120 (Advanced Bioscience Labs, Kensington, Md. overnight in phosphate buffered saline (PBS) pH 7.4 at 4° C.
[0112] 2. Wash plate with PBS and block wells with 1% BSA in PBS pH 7.4 for 2 hours at room temperature.
[0113] 3. Acid 50 ul of glycomimetic antigen in 1% BSA, PBS pH 7.4 serially diluted from well 1 to 11, with well 12 containing buffer but no antigen.
[0114] 4. Add 50 ul of antibody 2G12 (Polymun Scientific, Vienna, Austria) diluted in 1% BSA. PBS pH 7.4 to each well.
[0115] 5. Incubate rotating at room temperature for 2 hours.
[0116] 6. Wash plate with PBS and add secondary antibody (Pierce Chemical Co., Roekford, Ill.) conjugated with horseradish peroxidase (2 ug/ml) in 1% BSA, PBS pH 7.4.
[0117] 7. Incubate rotating at room temperature for 1 hour.
[0118] 8. Wash and add TMB (3,3′5,5′-letramethyl benzidine) reagent (100 ul/well) to each well. Wait 10 minutes. Stop reaction by adding 100 ul of 1 M phosphoric acid to each well, and read optical density at wavelength 450 nm.
[0119] The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents. U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.
[0120] These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
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Compounds, compositions and methods are provided for use to inhibit infection by human immunodeficiency virus (HIV). More specifically, the present invention relates to glycomimetic compounds that inhibit HIV infection, and uses thereof.
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BACKGROUND OF THE INVENTION
The present invention relates to an appliance for correcting rachidial deformities and essentially scoliosis, which is the major cause of such deformities.
The appliance is intended to be surgically implanted along the deformed part of the rachis or vertebral column of a growing child and to remain there a number of months or years during which it exerts a corrective mechanical action on the profile of the rachis for reducing the initial deformity. When growth is at an end or when the correction obtained is satisfactory, surgery takes place again in order to remove the appliance.
Scoliosis is a disease which deforms the rachis and reaches one or more rarely two segments thereof during the growth period. This deformity is particularly serious because, due to the fact that it combines a horizontal torsion and a flexion in a frontal plane, it develops in the three dimensions in space. It is also an evolutive disease, which starts during the growth phase, probably due to the rotation of one or two vertebral bodies. Scoliosis is in particular an evolutive dynamic disease and several known tests (particularly the bending test) show its at least partially correctable nature at the start of the disease. The deformity subsequently has a tendency to become fixed as a result of the stiffening of the articular parts and deformities of the osseous parts. It is therefore important to correct this deformity as early as possible after its detection.
The presently known treatments for scoliosis are firstly orthopedic and dynamic (wearing a rigid corset, traction exerted on the vertebral column particularly by suspending the patient by the head and kinesitherapy). Surgery is carried out if this treatment is inadequate and the deformity is aggravated. The object of the surgery is, after reducing to the maximum possible extent the deformities, to fix the lesions by means of rigid equipment and arthrodesis to prevent aggravation of the deformity. These methods are sometimes necessary to avoid the worst, but nevertheless have the serious disadvantage of being definitive and of stopping the deformity by stopping growth.
SUMMARY OF THE INVENTION
The object of the present invention is a process for the dynamic correction of rachidial deformities by a novel and original action mode on the deformities themselves.
According to the present process, a tension and a gentle torque are applied on a permanent basis to the angle formed by the spinous process and the disk of each vertebra of the deformed part of the rachis so as to obtain the slow and progressive correction of flexions and torsions of said part of the rachis, whilst attempting to bring it back to its normal state.
The present invention also relates to an appliance for the dynamic correction of rachidial deformities and particularly scoliosis utilizing the aforementioned process, which makes it possible to cure the same by a gentle, permanent action of a surgically implanted corrective appliance.
Thus, the present invention also specifically relates to an appliance for the dynamic correction of rachidial deformities, wherein in the deformed part of the rachis which it is wished to correct is implanted a mechanical assembly of biocompatible material comprising screwed onto each vertebra of the deformed area, in the angle formed by the spinous process and the disk, a retaining clamp having at least one guidance opening from one side to the other parallel to the axis of the rachis; and an elastic restoring or return structure having at least one elastic rod with a shape memory of the corresponding part of a normal rachis and introduced into the aforementioned guidance openings of the retaining clamp fixed to each vertebra, immobilized in rotation in each guidance opening and in translation on one of the retaining clamps.
The essential feature of the dynamic corrective appliance according to the invention is that it has an elastic restoring structure with a shape memory corresponding to a rachis with a normal profile, whereby to the diseased rachidial segment is permanently applied a tension and a gentle torque with the object of correcting its deformity. There is no doubt, and this is vital, that the permanent nature of a gentle action is much more effective for at least partly bringing about a correction of the rachis profile and preventing the aggravation of a scoliosis, than a violent, sudden action applied for a limited time. Thus, the gentle action resulting from the permanent stressing of the elastic restoring structure retaining in its memory the correct shape in the three dimensions of the corresponding part of a normal rachis is applied to all the components leading to the scoliotic deformity and in particular the rotation and inflexions in the frontal plane. The complete implanted appliance must obviously be made from a biocompatible material. As a non-limitative example, it is possible to choose stainless steel NSM 21 S (Ugine standard). The length and cross-section of the elastic restoring structure having a memory are defined as a function of the age of the patient and the dynamic performances which it is wished to obtain. It is designed to be placed at the bottom of the spinous fossa along the rear part of each diseased vertebra and must obviously be resistant to wear. Moreover, the very principle of the appliance according to the invention, means that the corrective force and the torque applied by the elastic restoring structure to the diseased rachis part are a direct function of the degree of geometrical deformity of said rachis and increase therewith, which is a very important advantage.
The corrective appliance according to the invention is to be used in a preventative rather than a curative capacity and is consequently fitted as early as possible during the evolutive period of the disease, when the deformities of the rachis are still flexible and the osseous parts have still not undergone any deformation. It is therefore necessary for the purpose of choosing the correct moment for applying the appliance according to the invention, to assess at a very early time the existence and evolutive character of an incipient scoliosis.
It is also pointed out that the rods of the elastic restoring structure, which are to some extent the active element of the corrective appliance according to the invention, are only slid into the guidance openings of the retaining clamps, so as to permit a completely free axial displacement of each vertebra, thereby enabling the growth of the rachis throughout the implantation period of the appliance. The guidance openings of the retaining clamps have a shape corresponding to the cross-section of the elastic rods excluding the rotation thereof about their axis in order to permit the application of torsional stresses, which would not be possible if the rods were able to rotate on themselves in each of the guidance openings. To this end and according to the invention, the guidance openings have a special shape and in particular chosen from oval or polyhedral cross-sections or in the form of rails and crosses. When the guidance openings has an oval cross-section, the major axis of this oval is preferably contained in a sagittal plane. At both their inlet and outlet, the guidance openings of the clamps can have a widened or flared shape, which permits a certain bending of the elastic rod between the different guidance points.
According to the invention, each retaining clamp of the elastic rod is fixed to the associated vertebra by any known means and in particular in accordance with the embodiments described hereinafter.
According to a first embodiment, each retaining clamp is fixed to the associated vertebra by direct screwing into the centro-lateral segment.
According to a second embodiment of the invention, each retaining clamp is fixed to the associated vertebra with the aid of a threaded rod passing through the spinous process and is secured on the other face thereof by a nut applying a bearing plate, which is located in the rear vertebral arch.
According to a third embodiment of the invention each retaining clamp is fixed to the associated vertebra by direct screwing into the vertebral pedicle.
In general terms, the three above embodiments are given in an illustrative and non-limitative nature and it is obvious that both the Expert and the surgeon can use any other fixing mode which he considers appropriate in the particular case and in particular any combination of the three aforementioned cases, without passing beyond the scope of the invention.
The above arrangements of the corrective appliance according to the invention permit the application of the corrective tension of the elastic rod or rods to the rear arch of each vertebra to which there is easy access all along the vertebral column. In general terms, the application point of corrective force must be located as close as possible to the vertebral rotation centre in order to have maximum effectiveness with regards to the torques applied. As this centre is located in the spinal canal, for obvious reasons it is not possible to apply a torque thereto. The closest area and also that which has the easiest access by the dorsal tract is the spine-disk angle, so that the corrective torque of the corrective appliance according to the invention is applied to this area. The appliance applies to the same area the restoring force aiming at correcting the pathological frontal curvatures acquired by a deformed rachis.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein show:
FIG. 1 a general perspective view of the corrective appliance according to the invention, in the case where the elastic restoring structure is constituted by a single elastic rod having a shape memory and which constitutes the active part of the appliance.
FIG. 2 a side view relative to FIG. 1 of the elastic rod fitted on a deformed portion of the rachis.
FIG. 3 an embodiment of the invention in the case where the elastic restoring structure is constituted by several parallel elastic rods.
FIG. 4 a constructional detail of the retaining clamps of the embodiment of FIG. 3.
FIG. 5 the flared shape of the square holes in the retaining clamp of the embodiment of FIG. 4.
FIGS. 6, 7 and 8 different possible methods for fixing the retaining clamps to the corresponding vertebrae.
FIG. 9 a special embodiment of the elastic restoring structure of the corrective appliance according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows four vertebrae 1, 2, 3 and 4 of a rachis portion suffering from a scoliosis-type deformity by turning the drawing to the left relative to the sagittal plane P passing through the axis of vertebra 1. It is possible to see on each vertebra the vertebral body 5 and the transverse processes 6, 7 and spinous process 8. According to the invention, retaining clamps 9, whose shape and fixing will be explained in greater detail with reference to following drawings, are located in the rear vertebral arch between the spinous process 8 and the transverse process 6. In the particular case of FIG. 1, the elastic restoring structure comprises a single rod 11 made from a biocompatible, elastic material. Each retaining clamp 9 is provided with an opening 10, into which is introduced the elastic rod 11 having a shape memory. For reasons of clarity, FIG. 1 only shows rod 11 in a partial manner by means of dotted lines.
The elastic rod 11 has been designed, prior to its implantation in the appliance of FIG. 1, so as to have a shape memory of part of a normal rachis corresponding to vertebrae 1, 2, 3 and 4 of FIG. 1 and consequently precisely exerts the permanent, gentle tension necessary for restoring said vertebrae by flexion and torsion to their correct initial position, i.e. in order to correct the overall rachidial position shown. The guidance openings 10 have a cross-section identical to that of the elastic rod 11 and which is in particular oval, so as to prevent any rotation of rod 11 about its axis in openings 10, thus permitting the torsional action of said rod 11 on the rachis part equipped with the appliance. Moreover, each guidance opening 10 optionally has widened or flared upper and lower ends, so as to permit the harmonious flexion of rod 11 between its different connecting points.
Rod 11, equipped with its different retaining clamps 9, is fixed by a set screw 12 to one of the same, in order to be blocked in longitudinal translation. All the other movements of the rod 11 are consequently permitted and its gentle frictional passage into the retaining clamps 9 makes it possible for the vertebral column of the patient to grow during the complete appliance implantation time.
In FIG. 1, the cross-section of the guidance openings 10 is oval, with a major axis located in a sagittal plane. However, this is not limitative and this cross-section can have a very variable shape, such as polyhedral, or can be shaped like a rail or cross, only a circular cross-section being impossible, because it would permit the rotation of rod 11 about its axis and would cancel out any possibility of a torsional stress thereof on the rachis.
It should also be noted that rod 11 only requires a fixing in translation at one of its retaining flanges, in order to prevent its sliding along the axis. This clamp can, for example, be one of the upper or lower end clamps of the appliance and it is merely necessary to have a small screw passing through the same to secure the rod once the appliance has been fitted.
FIG. 2 shows a profile view of the corrective appliance of FIG. 1, on which it is possible to see the four vertebrae 1, 2, 3, 4, the elastic rod 11 introduced into the flared oval openings 10 of the different clamps 9. It is also possible to see at 12, the outline of the translation fixing screw of rod 11 on the final clamp 9. FIG. 2 inter alia illustrates the curvature of the elastic rod 11 in a sagittal plane.
In FIGS. 1 and 2, the guidance openings 10 are not strictly cylindrical but, according to the invention, have a flared shape, enabling a certain bending of rod 11 between two consecutive retaining clamps 9. This precaution is indispensable to enable the rod to fulfil its complete function by supplying the vertebral column with the support necessary to permit the correction expected of it. In the same way, the guidance openings 10 have an oval cross-section, whereof the major axis is located in a sagittal plane in order to prevent the rotation of rod 11 on itself and to enable it to exert its torque on each vertebra.
FIG. 3 shows a very interesting variant of the appliance of FIG. 1, in which the elastic restoring structure is constituted by a group of four parallel elastic rods. FIG. 3 shows the same elements as in FIG. 1 and carrying the same reference numerals. The single elastic rod of FIG. 1 is merely replaced by the group of four square, elementary rods 13, 14, 15 16, maintained in place in the spine-vertebral segment angle by retaining clamps 17 having four square openings, whereof each corresponds to one of the elementary rods 13, 14, 15, 16 and which will be described in greater detail relative to FIG. 4.
This embodiment is of particular interest, because it makes it possible to use elastic elementary rods 13, 14, 15, 16 of a thinner or more slender type and whereof the thus formed assembly still has all the necessary elasticity and flexibility. Thus, it is possible either to use completely linear elementary rods 13, 14, 15, 16, or rods which are preshaped to a greater or lesser extent to the profile of a corresponding, normal rachis portion. As in the case of FIG. 1, the thus formed restoring structure exerts in a permanent manner on each vertebra a low intensity torque and force, which is the sought fundamental result for obtaining a progressive correction under good conditions.
FIG. 4 shows a larger-scale detail of one of the retaining clamps 17 of FIG. 3, whereof the characteristic curvature of the dorsal part 18 is intended to correspond to the concavity of the spinous zone-segment of each vertebra. Part 17 has four openings such as 19, which have a square cross-section and are flared at their upper and lower inlets, as will be shown relative to the following FIG. 5, in order to permit a certain bending of elementary rods 13 to 16 about each clamp 17. FIG. 4 is in fact a section through the centre of the thickness of clamp 17 showing the opening 20 reserved for screwing into the corresponding vertebra with the aid of a screw 21 having a head 22 which is located in the opening 20 of said clamp 17.
FIG. 5 is a section along line XX of FIG. 4 of one of the passage holes 19 for the elementary rods 13 to 16, whose flared shape is shown in the form of inclined planes 23 permitting a certain bending of the corresponding elastic restoring rod at the inlet and outlet of each square hole 19.
FIGS. 6 to 8 show different shapes and different fixing possibilities for a retaining clamp on the corresponding vertebra 1.
FIG. 6 corresponds to the embodiment of FIG. 1 using a single elastic rod 11 and a retaining clamp 9. The latter is fixed in the vertebral disk 25 with the aid of a screw 21. In a variant, is shown in mixed line diagrammatic form, another possible implantation of screw 21 at 26 in the vertebral pedicle.
In FIG. 7, the retaining clamp 17 corresponding to the embodiment with four elementary rods of FIG. 3, can be fixed as required by screws such as 26 and/or 27, which are either screwed into the vertebral pedicle, or through the spinous process.
Finally, FIG. 8 shows an embodiment having a single elastic rod 11 and a retaining clamp 9, which is fixed by screwing with the aid of screw 28 through the spinous process 29 using a support plate 30, located in the opposite disk-spine angle and which is tightened and prevented from rotation by a nut 31.
In general terms, these different fixing modes which can also be used simultaneously, will be chosen as a function of what is best in each particular case by the surgeon, who will utilize all the resources of the art to choose the best possible solution in each particular case.
FIG. 9 shows another embodiment of the elastic restoring structure of the corrective appliance according to the invention, which has a certain number of polyhedral elementary restoring rods 35, enclosed in a sheath 36 and held in position by retaining rings or collars 37. As in the previous embodiments, a retaining clamp 9 having the flared oval opening 10 surrounds sheath 36 and is fixed with a screw, diagrammatically shown at 38 to the corresponding vertebra.
In the special, non-limitative case of FIG. 9, the construction shown for this elastic restoring structure has ten hexagonal elementary rods in order to fill the interior of sheath 36. In order to improve this system, it would also be possible to envisage providing recesses on the periphery of the lateral faces of the elementary rods 35, so as to decrease the friction coefficient between two adjacent rods, so as to make the elastic structure assembly more flexible.
This embodiment is particularly interesting because it makes it possible to form, with the aid of easily realisable elementary rods, a larger elastic restoring assembly which can be easily preshaped and is also able to produce the restoring torque and forces with the desired intensity with respect to the sought objective.
In all the preceding embodiments, it is possible to use an elastic restoring structure with a linear shape, in which case only the rotations and flexions of the rachis in a frontal plane are corrected. If this is permitted by the bicompatible material used for the structure, it is also possible to preshape it to the profile of a normal vertebral column, thus enabling the corrective appliance, if necessary, to simultaneously act on the rachidial profile in a frontal plane.
The surgical fitting of the dynamic corrective appliance according to the invention takes place in the following way. The patient is firstly placed in ventral decubitus on an ordinary operating table. The surgeon acts on the two spinous fossas and releases the vertebral column up to the articular processes. He then makes the necessary perforations, either of the disk, or of the spinous process by means of a punch on the deformed rachidial segment. An elastic rod of appropriate size and having in its memory the shape of the corresponding part of a healthy rachis is then brought to the appropriate shape on the diseased segment in question. The different retaining clamps are placed on the rod and it is then placed along the rachis of the patient using three special clips and whilst maintaining it in the deformed state. The surgeon then passes the threaded rods into the openings or screws them down in a provisional manner according to the fitting procedure chosen, and also fits the nuts and bearing plates. Once securing and tightening of the assembly has taken place, it is possible to release the clips and the incision is then closed with draining.
The patient must get up immediately and, as it is usually a question of a growing child, he can resume schooling as soon as healing has taken place because no internal traumatism is caused by the fitting of this corrective appliance. It is also recommended that the child carries a lombostat in an almost permanent manner throughout the time when the corrective appliance is fitted to the rachis, in order to limit wear to the parts present as a result of the clearance of the elastic rod in the various retaining clamps. At the end of growth, the implanted internal corrective appliance, which has become useless, has to be removed.
It is finally pointed out that the clearance or play of the elastic restoring structure in the different retaining flanges 9, 17 permits the normal growth of the child and gives the complete appliance the flexibility required for the progressive correction of the deformity. Experience has shown that it is possible to permit a rachidial growth of 5 cm, without it being necessary to change the corrective appliance and replace it by another appliance of a larger size. This is a by no means unimportant advantage of the invention because, on average, this permits an increase in the overall size of the child by 20 cm.
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An appliance for the dynamic correction of rachidial deformities, wherein in the deformed part of the rachis which it is wished to correct is implanted a mechanical assembly of biocompatible material comprising screwed onto each vertebra of the deformed area, in the angle formed by the spinous process and the disk, a retaining clamp having at least one guidance opening from one side to the other parallel to the axis of the rachis; an elastic restoring or return structure having at least one elastic rod with a shape memory of the corresponding part of a normal rachis and introduced into the aforementioned guidance openings of the retaining clamp fixed to each vertebra, immobilized in rotation in each guidance opening and in translation on one of the retaining clamps.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for fabricating a capacitor for a semiconductor device, and more particularly, to a method for fabricating capacitors that exhibit both improved electrical properties and sufficient capacitance required for advanced semiconductor devices.
[0003] 2. Description of the Background Art
[0004] Recently, the degree of integration of memory products has been increased through the application of improved semiconductor processing techniques for producing increasingly smaller device structures. Accordingly, the unit cell area has decreased remarkably and the use of lower operating voltages has increased. Despite the decrease in the size of the cell area, however, the capacitance required to operate memory devices without generating soft errors and reducing refresh times has remained on the order of25 fF per cell. As a result, DRAM capacitor designs using a nitride-oxide (NO) structure as the dielectric film it has typically been necessary to utilize a three-dimensional electrode structure and/or a hemispherical grain surface (HSG) to obtain the necessary capacitance values. The three-dimensional electrode structures increase the effective surface area of the capacitors by increasing the height and vertical surface area of the electrode.
[0005] However, increasing the height of the capacitor electrode structures also complicates subsequent process steps, particularly with regard to photolithography and etch processes. As the height of the capacitor increases, the depth of focus and dimension control that can be obtained during subsequent photolithography processes may be insufficient to accurately reproduce the necessary patterns. This difficulty is the result of the height differences between cell regions and peripheral circuit regions, height differences that can adversely affect subsequent integration processes, particularly after interconnection processes and at increased degrees of integration.
[0006] It is difficult, therefore, to construct a DRAM capacitor using a conventional NO dielectric film that has sufficient capacitance to support DRAMs designs having 256M or more cells.
[0007] In order to overcome some of the disadvantages of the conventional dielectric materials, capacitors using a tantalum oxide film as the dielectric film have been developed. Tantalum oxide films, however, have a non-uniform and unstable stoichiometry that generates vacancy Ta atoms as a result of variations in the composition ratio between tantalum and oxide atoms in the thin film. Thus vacancy Ta atoms in the form of oxygen vacancies are always present in the tantalum oxide film because of its unstable chemical composition.
[0008] Although the number of oxygen vacancies within the tantalum oxide film may be varied somewhat depending on the actual composition and the bonding degrees of the incorporated elements, there is presently no technique or method that will completely eliminate the oxygen vacancies. As a result, a special oxidation process intended to more completely oxidize the tantalum atoms in the thin film is required to stabilize the stoichiometry and thereby prevent generating a leakage current. Additionally, the tantalum oxide film is highly reactive with both polysilicon (oxide film electrode) and titanium nitride (metal electrode), two materials commonly used to form the upper and lower electrodes of a capacitor. As a result, oxygen present in the tantalum oxide thin film may react with the electrode materials, thereby forming a low dielectric oxide layer at the interface and degrading the uniformity and electrical properties of the resulting capacitor.
[0009] In addition, during the formation of the tantalum oxide thin film, carbon (C), carbon compounds (such as CH 4 and C 2 H 4 ) and water vapor (H 2 O) are typically produced by the reaction between the organic tantalum source, frequently Ta(OC 2 H 5 ) 5 , other reaction gases such as O 2 or N 2 O. These impurities can, in turn, be incorporated into the resulting tantalum oxide film. These impurities, as well as other ions, free radicals, and oxygen vacancies, will tend to increase the leakage current and degrade the dielectric properties of the resulting capacitor.
SUMMARY OF THE INVENTION
[0010] Accordingly, a primary object of the present invention is to provide a method for fabricating a semiconductor device that incorporates a dielectric film having excellent electrical properties.
[0011] Another object of the present invention is to provide a method for fabricating a capacitor for a semiconductor device that has sufficient capacitance for the operation of the high integration semiconductor device, by using a dielectric film having a high dielectric constant.
[0012] Still another object of the present invention is to provide a method for fabricating a capacitor for a semiconductor device that can reduce production costs by both decreasing the number of necessary unit process steps and reducing the overall unit processing time.
[0013] In order to achieve the above-described objects, the present invention provides a method for fabricating a capacitor for a semiconductor device comprising the steps of: forming a lower electrode at the upper portion of a semiconductor substrate where a predetermined structure has been formed; forming an amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film on the lower electrode; and forming an upper electrode on the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film.
[0014] There is also provided a method for fabricating a capacitor for a semiconductor device, comprising the steps of: forming a lower electrode at the upper portion of a semiconductor substrate where a predetermined structure has been formed; forming an amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film on the lower electrode; performing a thermal treatment on the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film; and forming an upper electrode on the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film.
[0015] In addition, there is provided a method for fabricating a capacitor for a semiconductor device, comprising the steps of: forming a lower electrode at the upper portion of a semiconductor substrate where a predetermined structure has been formed; forming a (Ta 2 O 5 ) 1−x -(TiO 2 ) x dielectric film on the lower electrode; performing a thermal treatment on the (Ta 2 O 5 ) 1−x -(TiO 2 ) x dielectric film; and forming an upper electrode on the (Ta 2 O 5 ) 1− -(TiO 2 ) x dielectric film.
[0016] The present invention will become better understood in light of the following detailed description and the accompanying figures. The figures are provided by way of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1 to 3 are cross-sectional views illustrating certain of the sequential steps in fabricating a capacitor for a semiconductor device in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] A method for fabricating a capacitor for a semiconductor device in accordance with the present invention will now be described in detail and through reference to the accompanying figures.
[0019] As shown in FIG. 1, an interlayer insulating film 12 is formed at the upper portion of a semiconductor substrate 11 where a gate (not shown), a source (not shown), a drain (not shown) and a bit line (not shown) have previously been formed. A contact opening (not shown) is then formed to expose a predetermined lower electrode contact region of the semiconductor substrate 11 by selectively removing a region of the interlayer insulating film 12 . A first conductive film (not shown) is then formed on the upper portion of the interlayer insulating film 12 and in the contact opening. This first conductive film, preferably doped polysilicon, is then patterned and etched according to known photolithography and etch processes to form a lower electrode 13 .
[0020] Referring to FIG. 2, a dielectric film is formed by depositing an amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 with 0≦×≦0.5 over the entire structure using a low pressure chemical vapor deposition (LPCVD) process. This LPCVD process preferably employs two organic metal compounds, tantalum ethylate (Ta(OC 2 H 5 ) 5 ) and titanium isopropylate (Ti[OCH(CH 3 ) 2 ] 4 ), as the metal sources for the (Ta 2 O 5 ) 1−x -(TiO 2 ) x film. In order to remove any natural oxide film or other impurity present on the surface of the lower electrode 13 , it is preferable to perform a wet cleaning process using a HF solution, or a dry cleaning process using a HF vapor, either in-situ or ex-situ, before depositing the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 . In addition to the wet HF cleaning process, a solution of an addition compound such as Na 4 OH or H 2 SO 4 may be used to improve uniformity.
[0021] The amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 is the product of a series of chemical reactions at or near the surface of the wafer in the LPCVD chamber at a temperature of between 300 and 600° C. The LPCVD deposition is continued until the (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 has reached a predetermined thickness, preferably less than 100 Å. The Ta chemical vapor is obtained by supplying an organic tantalum precursor compound, preferably a Ta(OC 2 H 5 ) 5 solution, into an evaporator or evaporation tube at predetermined rate that is typically less than 300 mg/minute. The evaporator or evaporation tube is generally maintained at a temperature typically between 150 and 250° C. and the feed rate is typically controlled with a mass flow controller (MFC). The evaporated solution is then fed into the LPCVD chamber. The Ti chemical vapor is obtained in a similar fashion by supplying one or more organic titanium precursor compounds, preferably Ti[OCH(CH 3 ) 2 ] 4 , titanium tetrachloride (TiCl 4 ), tetrakis-dimethylamido-Ti (TDMAT), or tetrakis-diethylamodo-Ti (TDEAT) to an evaporator or evaporation tube at a predetermined rate, typically less than 300 mg/minute. The evaporator or evaporation tube is preferably maintained at a temperature above 150° C., and more preferably, a temperature ranging between 200 and 300° C. The Ti chemical vapor is then fed, either in combination with the Ta chemical vapor or via separate inlets, into the LPCVD chamber.
[0022] In order to prevent condensation of the organic metal compound vapors, the complete supply path between the evaporator and the LPCVD chamber, including any orifice, nozzle, or supply tube should be maintained at a temperature of at least 150° C., and preferably a temperature between 150 and 300° C.
[0023] The Ta and Ti chemical vapors and an additional reaction gas then react in the LPCVD chamber to form the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film. The feed ratio of the Ta and Ti chemical vapors may be adjusted to obtain a Ti:Ta mole ratio between 0.01 and 1.0. With feed rates of both the Ta and Ti chemical vapors below 300 mg/minute, the reaction gas, typically O 2 or N 2 O gas, will generally be fed into the LPCVD chamber at a rate of between 5 and 500 sccm during formation of the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 . An excess of the reaction gas, either O 2 or N 2 O, also serves to avoid both the formation of carbon impurities and the presence of vacancy Ta or Ti atoms in the thin film.
[0024] In addition, to improve a quality of the amorphous (Ta 2 O 5 ) 1−x (TiO 2 ) x film 14 and remove pin holes or micro cracks in the film, a low temperature thermal treatment may be carried out at a temperature below 600° C. in an atmosphere of O 2 or N 2 O with a flow rate of 5 to 500 sccm after the deposition of the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 .
[0025] On the other hand, in order to efficiently oxidize the minor amounts of vacancy Ta or Ti atoms and carbon impurities that remain in the thin film, and to enhance the bonding force, the low temperature thermal treatment is preferably performed by using UV-O 3 , or N 2 O or O 2 plasma, at a temperature ranging from 300 to 600° C. after the deposition of the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film 14 .
[0026] As shown in FIG. 3, a second conductive film 15 that will be used to form an upper electrode is formed over the entire structure. This second conductive film 15 may comprise a doped polysilicon film, a TiN film, or a metal substance selected from the group consisting of TaN, W, WN, WSi, Ru, RuO 2 , Ir, IrO 2 and Pt. The upper electrode may also comprise a multilayer structure including both a TiN layer and a doped polysilicon layer.
[0027] As discussed earlier, the method for fabricating the capacitor for the semiconductor device in accordance with the present invention has the following advantages.
[0028] Utilizing the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film (with a dielectric constant ε of between approximately 30 and 50) as the dielectric film for the capacitor provides a significantly higher dielectric constant than that available from a conventional NO film (ε=4˜5). Further, the titanium oxide film, with its tetragonal system structure, is more stable than the conventional tantalum oxide film (ε=25˜27) and is covalently bound in the structure of the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film, thereby providing enhanced mechanical and electrical strength. The capacitor of the present invention also exhibits improved resistance to electrostatic discharge (ESD) induced damage and thus provides superior electrical properties when compared with conventional capacitors. Moreover, the present invention prevents the oxygen vacancy and leakage current resulting from the unstable stoichiometry (Ta x Oy) and carbon impurities in the conventional capacitor relying on only a tantalum oxide film as the dielectric.
[0029] As a result, a capacitor constructed in accordance with the present invention provides a controlled dielectric that is equivalent to a oxide film of less than 20 Å. A capacitor according to the present invention thus provides a capacitance of over 25 fF per cell and improved electrical properties even at the level of integration necessary to support DRAMs of over 256M.
[0030] Therefore, the present invention does not require a complicated capacitor module having complex three-dimensional structures such as a step, cylinder, or fin electrode for increasing the effective electrode area. Especially, when the capacitor is fabricated using the amorphous (Ta 2 O 5 ) 1− -(TiO 2 ) x film as the dielectric film rather than the conventional tantalum oxide dielectric film, the ex-situ RTN process before the deposition of the tantalum oxide film, as well as the subsequent low temperature oxidation process and high temperature thermal treatment, may be eliminated. As a result, as compared with the conventional method, the number of unit processes is decreased and the corresponding unit processing time is reduced, thereby reducing production costs by as much as 30% or more.
[0031] Because the present invention may be practiced in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the invention is not, unless otherwise indicated, limited to the specific details of the foregoing descriptions. The present invention should be construed broadly within the spirit and scope as defined in the appended claims.
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The present invention discloses a method for fabricating a capacitor for a semiconductor device. The method includes the steps of: forming a lower electrode at the upper portion of a semiconductor substrate where a predetermined structure has been formed; forming an amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film on the lower electrode; performing a thermal treatment on the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film; and forming an upper electrode on the amorphous (Ta 2 O 5 ) 1−x -(TiO 2 ) x film. A capacitance for the operation of a high integration device is sufficiently obtained by using the (Ta 2 O 5 ) 1−x -(TiO 2 ) x film having a high dielectric constant, thereby fabricating the capacitor suitable for the high integration semiconductor device.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a Continuation Application claiming priority from the application having Ser. No. 11/125,288, filed date May 9, 2005, now U.S. Pat. No. 7,370,261.
TECHNICAL FIELD
The disclosure herein relates to data storage.
SUMMARY OF THE INVENTION
A method, system and computer program product for storing convolution-encoded data on a redundant array of independent storage devices (RAID) are described. In system form, embodiments comprise a plurality of storage devices and a trellis decoder coupled to the storage devices. The decoder is adapted to process coded data received from the storage devices to produce decoded data. The coded data comprises error correction coded data produced by the convolution of present and past bits of information. The system is adapted to determine if there is a failed storage device and in response to determining that there is a failed storage device the system allocates storage space for the storage of reconstructed data. The reconstructed data comprises coded data previously stored on the failed storage device. The system processes the decoded data to produce the reconstructed data and stores the reconstructed data on the allocated storage space.
In certain embodiments, the system is further adapted to measure a quantity of errors in the decoded data, compare the quantity of errors to an error limit for each of the plurality of storage devices and in response to the quantity of errors exceeding the error limit for a storage device, identifying the storage device as the failed storage device. In certain embodiments, the system is further adapted to receive self monitoring analysis and reporting technology information from the plurality of storage devices and in response to the self monitoring analysis and reporting technology information indicating a failure for a storage device, identifying the storage device as the failed storage device. In certain embodiments, the coded data comprises one or more words, each the word comprising n bits, where n is greater than zero, each the word produced from a convolution encoder processing a portion of information and none of the plurality of storage devices has two or more consecutive words or more than one of the n bits of each the word. In certain embodiments, the system further comprises a metadata controller adapted to process metadata associated with the coded data, the metadata comprising storage location information specifying a storage location for the coded data and/or specifying the type of encoding for the coded data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating aspects of an exemplary storage area network (“SAN”).
FIG. 2 illustrates an exemplary read command.
FIG. 3 illustrates a metadata structure.
FIG. 4 illustrates a convolution RAID with 1-bit wide stripes for 2-bit word-output encoders.
FIG. 5 illustrates a convolution RAID with 2-bit wide stripes for 2-bit word-output encoders.
FIG. 6 illustrates a flowchart for the reading of encoded data from a convolution-encoded RAID.
FIG. 7 illustrates a trellis decoder for (2,1,3) code.
FIG. 8 illustrates a flowchart for using a trellis decoder to detect missing encoded data.
FIG. 9 illustrates a flowchart for using a trellis decoder to reconstruct missing encoded data and the information it represents.
FIG. 10 illustrates a trellis decoder for (2,1,3) code, and with the reconstruction of missing information.
FIG. 11 illustrates a trellis decoder for (3,2,1) code.
FIG. 12 illustrates an encoder state diagram for a (2,1,3) error correction code.
FIG. 13 illustrates the encoder state diagram for a (2,1,3) error correction code of FIG. 12 in table form.
FIG. 14 illustrates a (2,1,3) binary convolution encoder circuit with two outputs, one input, and three stages of delay elements.
FIG. 15 illustrates an exemplary SCSI write command used to write reconstructed encoded data to spare storage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to figures, wherein like parts are designated with the same reference numerals and symbols, FIG. 1 is a block diagram that illustrates aspects of an exemplary storage area network (SAN) 10 . SAN 10 is typically designed to operate as a switched-access-network, wherein switches 67 are used to create a switching fabric 66 . In certain embodiments SAN 10 is implemented using the Small Computer Systems. Interface (SCSI) protocol running over a Fibre Channel (“FC”) physical layer. In other embodiments, SAN 10 may be implemented utilizing other protocols, such as Infiniband, FICON (a specialized form of Fibre Channel CONnectivity), TCP/IP, Ethernet, Gigabit Ethernet, or iSCSI. The switches 67 have the addresses of both the hosts 61 , 62 , 63 , 64 , 65 and controller 80 so that any of hosts 61 - 65 can be interchangeably connected to any controller 80 .
Host computers 61 , 62 , 63 , 64 , 65 are coupled to fabric 66 utilizing I/O interfaces 71 , 72 , 73 , 74 , 75 respectively. I/O interfaces 71 - 75 may be any type of I/O interface; for example, a FC loop, a direct attachment to fabric 66 or one or more signal lines used by host computers 61 - 65 to transfer information respectfully to and from fabric 66 . Fabric 66 includes, for example, one or more FC switches 67 used to connect two or more computer networks. In certain embodiments, FC switch 67 is a conventional router switch.
Switch 67 interconnects host computers 61 - 65 to controller 80 across I/O interface 79 . I/O interface 79 may be any type of I/O interface, for example, a Fibre Channel, Infiniband, Gigabit Ethernet, Ethernet, TCP/IP, iSCSI, SCSI I/O interface or one or more signal lines used by FC switch 67 to transfer information respectively to and from controller 80 and subsequently to a plurality of storage devices 91 - 93 . In the example shown in FIG. 1 , storage devices 91 - 93 and controller 80 are operated within RAID 90 . RAID 90 may also include spare storage 97 that may be exchanged with storage devices 91 - 93 in case of the failure of any of storage devices 91 - 93 . Additional storage in excess of storage devices 91 - 93 could be included in RAID 90 . Alternately, storage 91 - 93 could be physically remote from each other as well as controller 80 , so that a single disaster could jeopardize only one of storage devices 91 - 93 .
RAID 90 typically comprises one or more controllers 80 to direct the operation of the RAID. Controller 80 may take many different forms and may include an embedded system, a distributed control system, a personal computer, workstation, etc. FIG. 1 shows a typical RAID controller 80 with processor 82 , metadata controller 98 , random access memory (RAM) 84 , nonvolatile memory 83 , specific circuits 81 , coded data interface 85 and host information interface 89 . Processor 82 , RAM 84 , nonvolatile memory 83 , specific circuits 81 , metadata controller 98 , coded data interface 85 and host information interface 89 communicate with each other across bus 99 .
Alternatively, RAM 84 and/or nonvolatile memory 83 may reside in processor 82 along with specific circuits 81 , coded data interface 85 , metadata controller 98 , and host information interface 89 . Processor 82 may include an off-the-shelf microprocessor, custom processor, FPGA, ASIC, or other form of discrete logic. RAM 84 is typically used as a cache for data written by hosts 61 - 65 or read for hosts 61 - 65 , to hold calculated data, stack data, executable instructions, etc. In addition, RAM 84 is typically used for the temporary storage of coded data 87 from an encoder (i.e. encoder 86 ) before that data is stored on storage devices 91 - 93 . An example of an encoder is convolution encoder 220 ( FIG. 14 ). In certain embodiments convolution encoder 220 may reside in specific circuits 81 . RAM 84 is typically used for the temporary storage of coded data 87 after that data is read from storage devices 91 - 93 , before that data is decoded by decoder 77 . Examples of decoder 77 are trellis decoder 300 in FIG. 7 and trellis decoder 500 in FIG. 11 .
In certain embodiments, distributor 101 is implemented in processor 82 by software, firmware, dedicated logic or combinations thereof. In addition, all or part of distributor 101 may reside outside controller 80 , such as in a software implementation in one of hosts 61 - 65 . Distributor 101 distributes coded data (i.e. coded data 87 ) to RAM 84 , and/or directly to storage devices in a format such that the coded data and/or the source information may be decoded and/or reconstructed from non-failing storage devices in the case where one or more storage devices have failed. During a write process, when distributor 101 distributes the data to the storage devices, such as devices 91 - 93 , the distribution is done in accordance with metadata 88 , so that the distributed data can be later read from the storage devices. During a read process, distributor 101 retrieves the data from the storage devices, such as devices 91 - 93 , and reassembles coded data 87 to RAM 84 , based on the same metadata 88 .
Nonvolatile memory 83 may comprise any type of nonvolatile memory such as Electrically Erasable Programmable Read Only Memory (EEPROM), flash Programmable Read Only Memory (PROM), battery backup RAM, hard disk drive, or other similar device. Nonvolatile memory 83 is typically used to hold the executable firmware and any nonvolatile data, such as metadata 88 . Details of metadata 88 are further discussed below with reference to FIG. 3 .
In certain embodiments, coded data interface 85 comprises one or more communication interfaces that allow processor 82 to communicate with storage devices 91 - 93 . Host information interface 89 allows processor 82 to communicate with fabric 66 , switch 67 and hosts 61 - 65 . Examples of coded data interface 85 and host information interface 89 include serial interfaces such as RS-232, USB (Universal Serial Bus), SCSI (Small Computer Systems Interface), Fibre Channel, Gigabit Ethernet, etc. In addition, coded data interface 85 and/or host information interface 89 may comprise a wireless interface such as radio frequency (“RF”) (i.e. Bluetooth) or an optical communications device such as Infrared (IR).
In certain embodiments, metadata controller 98 is implemented in processor 82 by software, firmware, dedicated logic or combinations thereof. In addition, all or part of metadata controller 98 may reside outside controller 80 , such as in a software implementation in one of hosts 61 - 65 or another processing device. Metadata controller 98 , manages metadata associated with information received for storage as coded data on storage devices. In certain embodiments, metadata controller 98 is responsible for generating, changing, maintaining, storing, retrieving and processing metadata (i.e. metadata 88 ) associated with information received for storage as coded data.
Specific circuits 81 provide additional hardware to enable controller 80 to perform unique functions, such as fan control for the environmental cooling of storage devices 91 - 93 , controller 80 , and decoder 77 . Decoder 77 may be implemented as a Trellis decoder. Specific circuits 81 may comprise electronics that provide Pulse Width Modulation (PWM) control, Analog to Digital Conversion (ADC), Digital to Analog Conversion (DAC), exclusive OR (XOR), etc. In addition, all or part of specific circuits 81 may reside outside controller 80 , such as in a software implementation in one of hosts 61 - 65 .
Decoder 77 may be implemented as a trellis decoder to decode coded data read from RAID storage devices (i.e. storage devices 91 - 93 ). The operation of a trellis decoder may be explained by use of trellis diagram 300 ( FIG. 7 ). States S 0 -S 7 are shown in FIG. 7 and it is assumed that the initial contents of all memory registers, of the convolution encoder used to encode the information into the coded data stored on the storage devices are initialized to zero. For example, memory registers 230 - 232 of convolution encoder 220 ( FIG. 14 ) are initialized to zero. This has the result that the trellis diagram used to decode the coded data 87 read from the storage devices to produce the original host information 78 always begins at state S 0 and concludes at state S 0 .
Trellis diagram 300 ( FIG. 7 ) begins at state S 0 310 A. From S 0 310 A, trellis diagram 300 transitions to either S 0 310 B or S 1 311 B. The increase from suffix A to suffix B in the numbering of the states in trellis diagram 300 is called a branch, and the branch index I is zero when transitioning from suffix A to suffix B. From S 0 310 B, trellis diagram 300 transitions to either S 0 310 C or S 1 311 C; and from S 1 311 B, transitions to either S 2 312 C or S 3 313 C, and the branch index I is 1. From S 0 310 C, trellis diagram 300 transitions to either S 0 310 D or S 1 311 D; from S 1 311 C transitions to either S 2 312 D or S 3 313 D; from S 2 312 C transitions to either S 4 314 D or S 5 315 D; or from S 3 313 C transitions to either S 6 316 D or S 7 317 D, and the branch index I is 3.
The next series of transitions in trellis diagram 300 show the full breath of the decoding effort. From S 0 310 D, trellis diagram 300 transitions to either S 0 310 E or S 1 311 E; from S 1 311 D transitions to either S 2 312 E or S 3 313 E; from S 2 312 D transitions to either S 4 314 E or S 5 315 E; or from S 3 313 D transitions to either S 6 316 E or S 7 317 E, and the branch index I is 4. Also, From S 7 317 D, trellis diagram 300 transitions to either S 7 317 E or S 6 316 E; from S 6 316 D transitions to either S 5 315 E or S 4 314 E; from Ss 315 D transitions to either S 3 313 E or S 2 312 E; or from S 4 314 D transitions to either S 1 311 E or S 0 310 E.
Typically, what is shown for branch index I=4 is repeated a plurality of times in a trellis diagram. However, brevity permits only one such iteration in FIG. 7 . For the rest of FIG. 7 , the trellis diagram is shown to conclude, indicating the ending of the decoding process. From S 0 310 E, trellis diagram 300 transitions only to S 0 310 F; from S 1 311 E transitions only to S 2 312 F; from S 2 312 E transitions only to S 4 314 F; and from S 3 313 E transitions only to S 6 316 F, and the branch index I is 5. Also, from S 7 317 E, trellis diagram 300 transitions only to S 6 316 F; from S 6 316 E transitions only to S 4 314 F; from S 5 315 E transitions only to S 2 312 F; and from S 4 314 E transitions only to S 0 315 E. From S 0 310 F, trellis diagram 300 transitions only to S 0 310 G; and from S 2 312 F transitions only to S 4 314 G; and the branch index I is 6. Also, from S 6 316 F, trellis diagram 300 transitions only to S 4 314 G; and from S 4 314 F transitions only to S 0 310 G. Finally, from S 0 310 G trellis diagram 300 transitions only to S 0 310 H; and the branch index I is 7. Also, from S 4 314 G, trellis diagram 300 transitions only to S 0 310 H.
In FIG. 7 , example highlighted decoding path S 0 310 A, S 311 B, S 3 313 C, S 7 317 D, S 7 317 E, S 6 316 F, S 4 314 G, and S 0 310 H takes the encoded data 11100110010011 and decodes it into 1111000, per table 290 , FIG. 13 .
Flowchart 700 , shown in FIG. 6 outlines a process to implement one embodiment to decode error correction coded data obtained from RAID storage devices. The process begins at step 701 and flows to decision step 705 , to determine if controller 80 received a request for stored information from a source (i.e. host computers) 61 - 65 ). The information requested from controller 80 may have been previously stored on the storage devices by a customer, a third party providing a service to a customer, a user or any other entity that has access to controller 80 . If a request for stored information is not received, the process cycles back to step 705 . In certain embodiments, host information interface 89 receives the request for stored information and transfers the request to other components coupled to controller 80 (i.e. processor 82 , specific circuits 81 , etc.). If a request for stored information is received, the process flows to step 707 , where controller 80 first obtains the metadata 88 ( FIG. 3 ) associated with the desired stored information, based on the desired file name 626 (or other identifier) requested by one of hosts 61 - 65 , to determine upon what storage device(s) (i.e. by use of designator 621 , FIG. 3 ) the coded data has been placed, the starting LBA 622 of the coded data, the transfer length 623 to obtain the coded data, stripe width 624 , and the sequence number 625 . Metadata 88 could be obtained from nonvolatile memory 83 .
In certain embodiments a metadata controller (i.e. metadata controller 98 ) locates and processes metadata 88 associated with the coded data, the metadata comprising storage location information specifying a storage location for the coded data and/or encoder information specifying the type of encoding for the coded data. The storage location information specifying a storage location for the error correction coded data may comprise a storage device persistent name, a logical block address, a device number, a logical unit number, a volume serial number or other storage location identifiers. Processor 82 may be used to implement a metadata controller to locate the desired metadata 88 from nonvolatile memory 83 , in step 707 .
From step 707 , the process flows to step 708 , where controller 80 uses a read command (i.e. read command 605 FIG. 2 )) to read the coded information from individual storage 91 - 93 and place it into RAM 84 . For example, referring to FIG. 5 , V(1,1), V(1,2), V(4,1), V(4,2) V(7,1), V(7,2), V(10,1), V(10,2) etc., are read from drive 281 ; V(2,1), V(2,2), V(5,1), V(5,2) V(8,1), V(8,2), V(11,1), V(11,2) etc., are read from drive 282 ; and V(3,1), V(3,2), V(6,1), V(6,2) V(9,1), V(9,2), V(12,1), V(12,2) etc., are read from drive 281 to complete coded data 290 . Within read command 605 are the logical unit number 609 (obtained from metadata 88 , FIG. 3 ) of the target storage device, the starting logical block address 607 (obtained from metadata 88 , FIG. 3 ) and the transfer length 608 (obtained from metadata 88 , FIG. 3 ) of the coded data stored on the storage device at logical unit number 609 . Read command 605 maybe implemented across a SCSI or Fibre Channel interface. Read command 605 is a SCSI read command and it is only one possible read command which could be used. Read command 605 may be used more than once to retrieve the coded data from storage devices 91 - 93 . Read command 605 is typically used at least once for each storage device.
FIG. 4 shows an example of error correction coded data distributed to storage devices ( 260 ), when a (2,1,3) binary convolution encoder ( FIG. 14 ) was used to process the information to produce error correction coded data. Each word of the error correction coded data may comprise, for example two bits (n=2) as shown in FIG. 4 , the first word comprises V(1,1) and V(1,2), the second word comprises V(2,1) and V(2,2), the third word comprises V(3,1) and V(3,2), etc. For this example, none of the of storage devices receives more than one of the two bits of each the word.
FIG. 5 shows an example of error correction coded data distributed to storage devices ( 280 ), when a (2,1,3) binary convolution encoder ( FIG. 14 ) is used to process the information to produce error correction coded data. Each word of the error correction coded data may comprise, for example two bits (n=2) as shown in FIG. 5 , the first word comprises V(1,1) and V(1,2), the second word comprises V(2,1) and V(2,2), the third word comprises V(3,1) and V(3,2), etc. For this example, none of the of storage devices receives two or more consecutive words. For this embodiment, consecutive words comprises, for example, first word (V(1,1), V(1,2)) and second word (V(2,1), V(2,2)) or second word (V(2,1), V(2,2)) and third word (V(3,1) and V(3,2)). Examples of non consecutive words are: first word (V(1,1), V(1,2)) and third word (V(3,1) and V(3,2)) or second word (V(2,1), V(2,2)) and fourth word ((V(4,1), V(4,2)).
For the data distribution shown in FIG. 4 , read command 605 could be invoked six times in step 708 , to read the information stored in storage devices 261 - 266 . For the data distribution shown in FIG. 5 , read command 605 could be invoked three times in step 708 , to read the information stored in storage devices 281 - 283 .
Once all of the coded data has been read from each drive and placed into RAM 84 , the process flows to step 709 where controller 80 assembles the coded data from each drive into coded data 87 . Examples of coded data 87 assembled from the coded data read from each drive are 270 ( FIG. 4) and 290 ( FIG. 5 ). This assembly is based on the sequence number 625 in metadata 88 , where the sequence number determines the proper assembly of coded data 87 from the coded data previously spread across the RAID.
Similarly, FIG. 4 also shows a table ( 270 ) of an example of error correction coded data as stored in a memory device, for example RAM 84 , in step 709 . Table 270 is organized into columns, where each column comprises error correction coded data that was read in step 708 from a respective storage device (i.e. storage devices 91 - 93 ). For example, the first column of table 270 shows the error correction coded data read from drive 261 in step 708 .
FIG. 5 also shows a table ( 290 ) of an example of assembled error correction coded data 87 as assembled in a memory device, for example RAM 84 , in step 709 . Table 290 is organized into columns, where each column comprises error correction coded data that has been read in step 708 from a respective storage device. For example the first column of table 290 shows the error correction coded data read from drive 281 in step 708 .
After the completion of step 709 , where coded data 87 has been assembled in RAM 84 , the process flows to step 711 where coded data 87 is decoded to produce decoded data (i.e. information 78 ). Step 711 may be accomplished by a trellis decoder (i.e. trellis decoder 77 in specific circuits 81 , which decodes the coded data 87 to obtain the original information 78 for one or more of hosts 61 - 65 ) coupled to storage devices (i.e. by use of coded data 87 assembled in RAM 84 ). Trellis decoder 77 may be adapted to process coded data received from storage devices 91 - 93 to produce decoded data. The coded data comprising error correction coded data produced by the convolution of present and past bits of information 78 . Decoder 77 may be a trellis decoder represented by the diagrams of FIG. 7 or 11 , or any other trellis decoder. Alternately, decoder 77 could employ a “stack algorithm” which can be considered a binary, tree-like implementation of a trellis diagram.
In certain embodiments, decoder 77 , consists of expanding the state diagram of the encoder ( FIG. 12 ) in time, to represent each time unit with a separate state diagram. The resulting structure is called a trellis diagram, as shown in FIGS. 7 and 11 . The path through the trellis diagram with the smallest Hamming distance is the desired path for decoding (i.e. reading) the coded data 87 to produce the desired information 78 . The preferred smallest Hamming distance is zero, meaning that there is no error between coded data 87 and the path chosen through the trellis diagram to decode that coded data 87 into information 78 .
The Hamming distance is calculated by the word read for that branch of trellis diagram, and the word assigned to each path in that branch. The read word and the assigned word are added without carryover (XOR) to produce the Hamming distance for each path in that branch. For example if 111 was the word read, but a path had an assigned word of 010 the Hamming distance is 111+010101.
It is desired that the Hamming distance in each branch be zero. For example, if 111 was the word read, and there was a path in that branch with an assigned word of 111, then 111+111=000 would represent a zero Hamming distance. That path would be the desired path for that branch and the information assigned to that same path would then represent the original information before the encoding took place.
If a zero Hamming distance is not achieved, then all possible paths through the trellis diagram are calculated for the read encoded data, and the path with the minimum Hamming distance across all branches is chosen as the path representing both the encoded data and the original information. Thus, the trellis diagram is in fact a maximum likelihood decoding algorithm for convolutional codes, that is, the decoder output selection is always the code word that gives the smallest metric in the form of the Hamming distance.
For the read (decoding) process, the first branch of the trellis diagram always emanates from state S 0 and the last branch of the trellis diagram always terminates at state S 0 . This is indicative of beginning and ending the encoding process with all memory initialized to zero in the convolution encoder, such as memory 230 - 232 in FIG. 14 .
For proper operation, decoder 77 obtains the ordering of the bits which comprise the words from metadata 88 , via stripe width 624 . For example, the bits in table 270 ( FIG. 4 ) and table 290 ( FIG. 5 ) are arranged differently. By accounting for the stripe width 624 in metadata 88 , the individual bits of encoded data are processed in the correct order by trellis diagrams 300 ( FIG. 7) and 500 ( FIG. 11 ).
In certain embodiments the coded data comprises one or more words, each word comprising n bits, where n is greater than zero, each word produced from a convolution encoder processing a portion of information and where none of the plurality of storage devices has more than one of the n bits of each the word.
In certain embodiments the coded data comprises one or more words, each word comprising n bits, where n is greater than zero, each word produced from a convolution encoder processing a portion of information and where none of the plurality of storage devices has two or more consecutive words.
From step 711 , the process flows to step 712 , to determine if all of the coded data necessary to produce the information requested by a requester has been decoded by decoder 77 . If the answer is YES, the process flows to step 713 , where host information interface 89 receives information 78 from decoder 77 and any other components coupled to controller 80 (i.e. processor 82 , specific circuits 81 , etc.) which may be necessary to enact that transfer, and transfers information 78 derived from coded data 87 to the requesting host 61 - 65 . Information 78 may be temporary stored in a memory device (i.e. RAM 84 , nonvolatile memory 83 , a dedicated processor memory, etc.) before, during or after decoder 77 processes error correction coded data 87 . The error correction coded data 87 and/or the derived information 78 may be stored in RAM (i.e. RAM 84 ) in advance of distribution to the requesting host computers 61 - 65 of SAN 10 . Alternatively, the error correction coded data 87 may be stored in nonvolatile memory 83 , another memory device, cache memory, etc as it is being assembled from the segments being read (by read command 605 of FIG. 2 ) from the storage devices. In certain embodiments, error correction coded data 87 is stored in RAM 84 in a format identical to the format that was used previously for distribution to the storage devices for storage.
If at step 712 , all of the coded data 87 has been decoded, then step 713 is executed. Step 713 sends the information 78 requested by the requestor to the requester and returns program control to step 705 to process another request. If at step 712 , more coded data 87 needs to be decoded, then step 715 is executed.
At step 715 , the trellis decoding of coded data 87 may detect errors. In certain embodiments, each time that a non-zero Hamming distance is uncovered in the decoding process, a decoding error is detected. If there are no errors detected in the decoding of the coded data 87 , (i.e. a path is found in either trellis diagram 300 or 500 with zero Hamming distance) then control flows back to step 711 to continue the decoding process. In certain embodiments, step 715 is implemented by continuously examining the decoding of the coded data to detect errors via non-zero Hamming distances. Alternately, the decoding process may be examined periodically. For example, continuously or periodically examining may comprise examining bit by bit, multiple bits, word by word, multiple words or other portion of coded data, decoded data or derived information to detect errors. In there are errors in the coded data, decoded data, derived information or combinations thereof then control flows to step 720 to determine if a storage device has failed.
If at step 720 , a storage device has not failed, then step 722 is executed. At step 722 , the errors are corrected and control returns back to step 711 to resume decoding coded data 87 . This error correction would consist of backing up the decoding process to before an error (non-zero Hamming distance) existed that then resuming the decoding process while looking at all possible paths for the minimum Hamming distance. This minimum Hamming distance is preferably zero.
In one embodiment step 720 is accomplished by measuring a quantity of ECC (error correction code) errors in reading of the encoded data within individual storage devices (i.e., within each of storage devices 91 - 93 ) and comparing the quantity of ECC errors to an error limit within each of the storage devices (i.e. storage devices 91 - 93 ), in step 715 . In response to the quantity of ECC errors exceeding the error limit for a given storage device, the system identifies that storage device as a failed storage device in step 720 .
In an alternative embodiment, step 720 is accomplished by receiving Self Monitoring Analysis and Reporting Technology (i.e. S.M.A.R.T. technology) information from each storage device (i.e. storage devices 91 - 93 ) and in response to the self monitoring analysis and reporting technology information indicating a failure for a storage device, identifying that storage device as a failed storage device.
S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended to recognize conditions that indicate a drive failure (i.e. storage devices 91 - 93 ) and is designed to provide sufficient warning of a failure to allow data back-up before an actual failure occurs. A storage device may monitor specific attributes for degradation over time but may not predict instantaneous drive failures.
Each attribute for degradation monitors a specific set of failure conditions in the operating performance of the drive, and the thresholds are optimized to minimize “false” and “failed” predictions S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the rate of degraded error rate increases to an unacceptable level. To determine rate, error events are logged and compared to the number of total operations for a given attribute. The interval defines the number of operations over which to measure the rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter.
S.M.A.R.T. measures error rate, hence for each attribute the occurrence of an error is recorded. A counter keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter. Error rate is simply the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of error is to set thresholds for the number of errors and the interval. If the number of errors exceeds the threshold before the interval expires, then the error rate is considered to be unacceptable. If the number of errors does not exceed the threshold before the interval expires, then the error rate is considered to be acceptable. In either case, the interval and failure counters are reset and the process starts over.
S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. Firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incremented whenever the error rate is unacceptable and decremented (not to exceed zero) whenever the error rate is acceptable. Should the counter continually be incremented such that it reaches the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History Counter. There is a separate Failure History Counter for each attribute.
In an alternative embodiment, a failed storage device is determined in step 720 as a storage device which controller 80 cannot establish I/O communications with, for example, across coded data interface 85 .
If a storage device fails, flowchart 700 can be accessed via step 719 to flow directly to step 725 . It is not necessary for a read operation to occur to search for a failed drive and to begin the reconstruction of the encoded data previously held by the failed drive.
In response to determining that there is a failed storage device at step 720 , step 725 is executed to allocate storage space for the storage of reconstructed data. In certain embodiments step 725 is accomplished by using a spare storage device (i.e. spare storage device 97 ) for the allocated storage space. If such a spare storage device 97 is employed to replace one of storage devices 91 - 93 , spare storage device 97 would have as much or more storage capacity as the failed device which it is replacing. Additionally, spare storage device 97 would preferably be of the same type of storage, namely if storage 91 - 93 were hard disk drives with fibre channel connectivity, then spare storage device 97 would also be a hard disk drive with fibre channel connectivity. In certain embodiments the allocated storage space may comprise one or more of storage devices 91 - 93 , portions of storage devices 91 - 93 , an external storage device internal or external to SAN 10 , a memory device coupled to controller 80 , etc. In certain embodiments, the reconstructed data comprises coded data (i.e. data produced by a convolution encoder) previously stored on the failed storage device.
From step 725 , the process flows to step 730 , to accomplish ( 1 e , 14 e , 8 f ) processing the decoded data to produce the reconstructed data and storing the reconstructed data on the allocated storage space. Steps 730 and 735 may be accomplished by, for example, controller 80 processing decoded data by use of trellis decoder 77 and reconstructing an image of the data that was stored on the failed storage device, via constructing the entire contents of table 270 ( FIG. 4 ) or table 290 ( FIG. 5 ) in RAM 84 , and storing the column of that image, corresponding to what had been on the failed drive, onto the allocated storage space (i.e. spare storage 97 ) using a write command (i.e. write command 600 , FIG. 15 ). The image may be temporarily stored in a memory device (i.e. RAM 84 ) before, during or after the reconstruction process. This reconstruction process also recovers the information originally provided by the host. Thus, the reconstruction process also decodes the previously encoded data and the reconstruction process can be considered part of the read process, if the read process requires the reading a segment of encoded data which had been stored on a failed device. If a user desires the reading (decoding) of data on a failed convolution encoded RAID, such as in FIGS. 4-5 , the same reconstruction process which recovers the missing encoded data from the failed storage device or devices also provides the user with the desired information. In certain embodiments, the system may be adapted to charge a customer (i.e. a user) a fee for storing the reconstructed data on the allocated storage space. The fee may be billed to the customer by the system, a service provider, a third party etc. The fee may be based upon the amount of storage space used, a flat fee, the number of allocated storage devices used, etc. This may be accomplished by, for example a customer agreement with a service provider to store data, where the service provider is responsible for storing and retrieving a customer's data, on demand. The service provider may be the manager of the storage system and/or a third party in a business relationship between the customer and another entity. The customer may be provided with a connection to a system for storing information (i.e. SAN 10 , FIG. 1 ). The customer may send his information to the system for storage using the connection or other means. The amount or quantity of information sent by the customer or received by SAN 10 and/or controller 80 may be measured by methods known in the art for measuring the amount of data. The fee for storing reconstructed data on the allocated storage space could be determined by considering the amount of information sent for storage and other factors such as: rate of information flow, frequency of use, compressed or non-compressed information, fixed monthly rate or other considerations. From step 735 , the process flows to step 740 , to end.
In certain embodiments, steps 720 , 722 and 730 are accomplished by operation of decoder 77 . Decoder 77 may be implemented as a trellis decoder to decode coded data read from RAID storage devices (i.e. storage devices 91 - 93 ). The operation of a trellis decoder is explained below.
In certain embodiments, steps 720 and 722 are accomplished by steps 341 , 342 , 343 , 344 , 345 , 347 and 348 of flowchart 340 illustrated in FIG. 8 , and flowchart 360 illustrated in FIG. 9 , for the trellis decoding in FIGS. 7 , 10 , and 11 . In FIG. 8 , the process begins with step 341 . The process flows to step 342 , where the branch index I is set to zero. A branch of the trellis diagram represents one word of the output of the convolution encoder ( FIG. 12 ). For example, trellis diagram 300 has two bits in a word, and trellis diagram has three bits in one word. The branch index I is important because the trellis decoder typically sequentially decodes one branch at a time when a zero Hamming distance is obtained, which means that no errors have been detected and there is no missing data from a failed storage device and that a single path in branch index I has been identified which corresponds exactly with the encoded data word in coded data 87 . The value of the trellis decoder is that it can “look ahead, out of sequence, by branch” and bypass branches with errors, and use those branches which follow the errant branch to correct that errant branch.
From step 342 , the process flows to decision step 343 , where the determination is made whether all n bits of a word of coded data 87 were obtained from the storage devices 91 - 93 or if some of the bits are missing for branch I. Each word comprises n bits, and each set of n bits comprises one branch in trellis decoder 300 and 500 . If all n bits were obtained for branch I, the process flows to step 344 where the XOR (exclusive OR) operation is performed between (a) all n bits of the encoded data obtained from coded data 87 and (b) the state transitions in the pats comprising branch index I of trellis diagram 300 of FIG. 7 (or, alternately, trellis diagram 500 of FIG. 11 ). For example, for branch index I=0 of trellis diagram 300 of FIG. 7 , the encoded data read is 11 (a single word of encoded data is processed at a time). Trellis diagram allows transitioning from S 0 310 A to either S 0 310 B or S 1 311 B. The transition from S 0 310 A to S 0 310 B represents the encoded data 00 and the transition from S 0 310 A to S 1 311 B represents the encoded data 11 . The XOR process between the read data of 11 and the transition from S 0 310 A to S 1 311 B gives a zero Hamming distance (zero error) in decision step 345 (11 XOR 11=00), indicating that this is the proper choice to make between the two possibilities and that the decoded and desired decoded information is a 1. If a path is identified with zero Hamming distance (zero error) in decision step 345 , the process flows to step 347 where that path with zero Hamming distance is chosen as the correct path. The process then flows to decision step 348 , where the assessment is made whether the process has concluded by whether all data has been processed per metadata 88 , which determines the size of coded data 87 . Assuming the process is not concluded yet in step 348 , the branch index I is increased by I in step 349 and the process returns to attempt to read more data in step 343 . If the process is completed in step 348 , the process proceeds to step 398 where the original information 78 which was obtained by decoding coded data 87 is sent to one of hosts 61 - 65 , and then the process ends in step 399 .
In certain embodiments, steps 720 , 725 , 730 and 735 ( FIG. 6 ) are accomplished by arriving at step 351 via step 343 of flowchart 340 illustrated in FIG. 8 for the trellis diagram 300 of FIG. 7 or trellis diagram 500 of FIG. 11 . If in decision step 343 , all n bits were not obtained (i.e., all bits of a branch were not obtained, as is shown as the I=1 dotted-line path of FIG. 10 ), the process flows to step 350 where the number of missing bits Q is determined. For example, for a word of length, n=2 bits, Q could be 1 in the case of one of devices 263 - 264 ( FIG. 4 ) has failed and the other is fully operational. However, Q would be equal to n if one of devices 281 - 283 ( FIG. 5 ) failed, The process then flows to decision step 351 , where the query is made whether spare storage is already available, such as spare storage 97 of FIG. 1 . If the answer is no in step 351 , the process flows to step 352 where spare storage is obtained by the user to replace failed storage. In certain embodiments, the system may be adapted for charging a customer (i.e. the user) a fee for allocating storage space for the spare storage. Obtaining spare storage 97 may involve the user purchasing the spare storage, for example, if the warranty has expired for the failed storage. This purchase would typically be made electronically, when the customer first invokes the spare storage. If the warranty period is still active, then spare storage may be provided for free.
In certain embodiments, the spare storage devices remains unpurchased by the user until the spare storage devices are needed by the user. The cost of the spare storage may be zero, if the spare storage is invoked during a warranty period. Step 352 could also include the automatic shipment of replacement spare storage by the manufacturer as existing spares are utilized. This replacement spare storage would be placed where the failed storage was removed. In certain embodiments, the replacement storage may be located in a different physical location then storage devices 91 - 93 . For example, the replacement storage may be accessed on demand, by a high speed interface (i.e. internet, intranet, TCP/IP, etc.). The failed storage may be returned to the factory for failure analysis, as part of the warranty agreement. Then the process flows from step 352 to step 353 where a transition is made to step 361 of flowchart 360 of FIG. 9 . If in step 351 the answer is yes, the process flows directly to step 352 and to step 353 . In certain embodiments the storage devices (i.e. storage devices 91 - 93 in RAID 90 ) are disbursed to separate physical locations. For example, storage devices 91 , 92 and 93 may each be physically separated from each other by locating storage devices 92 - 93 in different rooms, buildings, cities, states, countries, etc.
In FIG. 10 , it is assumed that the encoded data comprises words of two bits, such as data encoded by the encoder shown in FIG. 12 . It is also assumed that a pair of adjacent devices with a 1-bit wide stripe such as devices 263 - 264 in FIG. 4 , or a single device with a 2-bit wide stripe such as device 282 of FIG. 5 has lost all data, due to a catastrophic failure. FIGS. 8-9 show how that data is reconstructed in case it cannot be read in step 343 of flowchart 340 .
In certain embodiments, steps 720 , 725 , 730 and 735 ( FIG. 6 ) are accomplished by arriving at step 351 via step 346 of flowchart 340 illustrated in FIG. 8 . If in decision step 345 , a path with zero error is not identified, the process flows to step 346 where all n bits of the processed word are assumed to be errant, by setting Q=n, and the process flows to aforementioned decision step 351 and then to step 361 of flowchart 360 ( FIG. 9 ).
In FIG. 9 , the process starts in step 361 and flows to decision step 362 , where the determination is made whether all bits n in branch I are lost, (i.e. Q=n), and all n bits need to be reconstructed because of the loss of branch I. If the answer is yes in step 362 , the process flows to step 363 , where lost branch I is skipped over and a total of (Q−1)*n more bits are read from the next Q−1 branches, which represents Q−1 words. This is the value of the trellis diagram, where it is possible to “look ahead” and use subsequent branches to determine missing encoded data from branch I. Then, in step 364 , the XOR (exclusive OR) process is performed in groups of n bits between the n read bits and the permissible paths in the I+1 to I+(Q−1) branches of trellis diagram 300 . Then in step 365 , the desired paths in branches I+1 to I+(Q−1) branches are those branches with zero Hamming distance (i.e., zero error) and those previously identified branches which connect to each other with zero Hamming distance. A zero Hamming distance is equivalent to a zero error in the decoding.
Once the decoding path is established in branches I+1 to I+(Q−1), the missing branch I is reconstructed as that path which connects the path in previously identified branch I and newly identified branches I+1 to I+(Q−1). This “connectivity” is critical in establishing the correct path through the trellis diagram. The entire decoded path, shown as the highlighted line in trellis diagram 300 of FIG. 7 , is achieved by the continuous connection of the individual paths in each branch in the trellis diagram. It is this reconstructed path, identified by zero Hamming distance, which is written to the spare devices purchased in step 351 . Then the process flows from step 365 to step 366 ( FIG. 9 ), where the branch index is incremented by Q−1 to account for the branches decoded during this phase of the reconstruction process. Then the process flows from step 366 to step 378 where the restored missing encoded data is stored on the spare storage. Then the process flows from step 378 to step 379 where the process returns to step 355 of FIG. 8 .
FIG. 10 gives an illustrative example of data reconstruction for data encoded via the (2,1,3) convolution encoder shown in FIG. 12 In the case of FIG. 10 , all data lost is that comprising branch index I=1, which means that Q=2 lost bits and Q=n. The final known state is S 1 311 B, which was just calculated for branch index I=0. FIG. 10 was created from trellis diagram 300 of FIG. 7 , with all the impossible states removed from trellis diagram 300 . For FIG. 10 , for branch I=1, from S 1 311 B, the only permissible transitions are to S 2 312 C and S 3 313 C and the determination of which of these two transitions was actually made by the encoded data needs to be made in order to reconstruct the missing/destroyed encoded data of branch I. To reconstruct the missing data, for branch I=1, flowchart 340 ( FIG. 8 ) “looks ahead” and the encoded data is read from coded data 87 for branch I+Q−1, which is branch I=2 (Q=2), as described in steps 364 , and that encoded data is 01 per FIG. 10 . The transition from S 2 312 C to S 4 314 D represents 11 per table 290 of FIG. 13 , and the transition from S 2 312 C to S 5 315 D represents 00. Similarly the transition from S 3 313 C to S 6 316 D represents 10 per table 290 of FIG. 13 , and the transition from S 3 313 C to S 7 317 D represents 01.
Per step 364 of flowchart 360 ( FIG. 9 ), the XOR process between the encoded data read for branch I=2 (I+Q−1=2) and the encoded data represented by the four possible paths for branch I=2 gives the following results: for S 3 313 C to S 7 317 D, 01 XOR 01=00, S 3 313 C to S 6 316 D, 10 XOR 01=11, S 2 312 C to S 5 315 D, 00 XOR 01=01, and S 2 312 C to S 4 314 D, 11 XOR 01=10. Thus, S 3 313 C to S 7 317 represents the only viable path based on a zero Hamming distance (01 XOR 01=00) for branch I=2. Based on the required connectivity between decoded paths in a trellis diagram, the missing encoded data must be represented by the transition from S 1 311 B to S 3 313 C in branch I=1 and missing encoded data is 10. Thus the encoded data for branch I=1 and I=2 is 10 and 01 and the decoded information is 11 for these two branches. Because the decoding was done for two branches, the branch index must be increased by Q−1=1 in step 366 and again by one in step 348 , assuming the decoding process to be ongoing. The reconstructed encoded data is stored on spare storage 97 of RAID 90 . If this reconstruction was done as part of a user-initiated read process, the original information obtained as part of the reconstruction process is placed in RAM 84 , for example, for eventual transmission to one of hosts 61 - 65 .
Steps 363 - 366 ( FIG. 9 ) reconstructs all n bits in branch I. If in step 362 , Q is not equal to n, then some but not all bits of branch I have been recovered and the process flows from step 362 to step 370 for the partial reconstruction of branch I.
In step 370 , the available bits which are read are XOR'd with each permissible path in branch I of the trellis decoder. The process then flows from step 370 to decision step 371 , where the decision is made whether there is enough surviving information to uniquely identify the desired path in branch I with zero errors for the bits read. If the answer is yes, the process flows to step 372 , where the path in branch I is chosen with zero error to give both the original data and the missing encoded data. Then the process flows from step 372 to step 378 where the restored missing encoded data is stored on the spare storage. Then the process flows from step 378 to step 379 where the process returns to step 355 of FIG. 8 .
An example of partially complete information in branch I of FIG. 10 is if one bit is retrieved for branch I=1, and one bit is missing. The presence of partially recovered data in branch I=1 is detected in step 362 of FIG. 9 . The path from S 1 311 B to S 2 312 C represents the encoded data 01. The path from S 1 3113 to S 3 313 C represents the encoded data 10. Thus, if either the lead bit or trailing bit of the two-bit pair of data is available, this is sufficient to determine the correct path for branch I=1 of FIG. 10 , via steps 371 - 372 of FIG. 9 . For example, if the lead bit is a 1 and the trailing bit is the lost bit, then, the reconstructed encoded data is 10 based on the only permissible path in branch I=1 with a leading I is S 1 311 B to S 3 313 C, i.e. it is the only permissible path which would result in a zero Hamming distance. The reconstructed data is then stored on spare storage 97 of FIG. 1 in step 378 of FIG. 9 . If this reconstruction was done as part of a user-initiated read process, such as process 700 of FIG. 6 , the original information obtained as part of the reconstruction process is placed in RAM 84 .
If in step 371 there are not enough surviving bits of coded data to uniquely identify a path in branch I with zero Hamming distance for the bits read, the process flows to step 373 where the next n bits are read from coded data 87 to form the word which is analyzed in branch I+1 of the trellis diagram, and then the process flows to step 374 . In step 374 , the XOR of n read bits with each permissible path in branch I+1 of the trellis decoder is accomplished to isolate the path with zero Hamming distance (zero error). FIGS. 7 and 11 are examples of specific trellis decoders 300 and 500 . Paths in branch I+1, which are incompatible with the partially read branch I, are not considered permissible and are ignored. The process flows from step 374 to step 375 , where the process chooses the path in branch I+1 with zero Hamming distance (zero error). The path in branch I is chosen so that the path already identified in branch I−1 and I+1 are all connected, which means that the individual branch paths must be connected to the paths in the adjacent branches all the way across the trellis diagram. In this manner, the missing encoded data for branch I and the original information for both branch I and branch I+1 is identified. Then the process flows from step 375 to step 377 , where the branch index I in incremented by unity. Then the process flows from step 377 to step 378 , which has already been described.
If there are three bits in a word, such as taught by trellis diagram 500 of FIG. 11 , then recovery of branch I may take a “look ahead” of branch I+1 and I+2 in order to find the connected path through branches I−1, I, I+1 and I+2 with zero Hamming distance.
Data reconstruction may be done, after a failure, either by using a background process or by use of a foreground process. A background process is where controller 80 performs data reconstruction independently of any involvement of hosts 61 - 65 . A foreground process is where controller 80 is specifically requested to reconstruct data by one of hosts 61 - 65 . Data may be reconstructed in the background from the very first stripe to the very last stripe. Also, data can be reconstructed in the foreground, when demanded by the customer, because data files are encoded independently from one another. Once data is reconstructed in the foreground, it need not be reconstructed in the background, provided that controller 80 monitors the reconstruction effort in the background and scans for what files have already been reconstructed in the foreground. It is not necessary for the encoded data to be reconstructed twice, once in the foreground (based on user demand as requested by one of hosts 61 - 65 ) and again in the background (because the background process run by controller 80 ignored that the missing encoded data was already reconstructed in the foreground).
State diagram 200 for (2,1,3) binary convolution encoding is shown in FIG. 12 . It is trellis decoder 300 of FIG. 7 , which is used during read process 700 of FIG. 6 from RAID 90 to one of hosts 61 - 65 , which decodes the coded data 87 created by state diagram 200 during the original write process from one of hosts 61 - 65 to RAID 90 . State diagram 200 comprises eight states: S 0 210 , S 1 211 , S 2 212 , S 3 213 , S 4 214 , Ss 215 , S 6 216 and S 7 217 . Discrete transitions between states, in state diagram 200 , are limited in number and direction. For example, the encoding process starting at state S 0 210 can only transition back to S 0 210 or forward to S 1 211 . Similarly, the process from S 1 211 can only transition to S 2 212 or S 3 213 , etc. Each transition between states in state diagram 200 results in the encoding of one bit of information into two bits of error correction coded data. This encoding is further explained with reference to table 290 in FIG. 13 .
Table 290 in FIG. 13 has four columns: initial state 291 , destination state 292 , information 293 and error correction coded data 294 . There are a total of sixteen rows in table 290 , based on a total of eight states in state diagram 200 and two possible transitions from one specific state to the next immediately-possible states. Table 290 was generated via state diagram 200 and is used herein to illustrate both the encoding of information to produce coded data and the decoding of encoded data to obtain the original information.
In FIG. 12 , highlighted encoding path comprising: S 0 210 , S 1 211 , S 3 213 , S 7 217 , S 7 217 , S 6 216 , S 4 214 and S 0 210 is shown for the example encoding of input information 1111000. S 0 210 to S 1 211 encodes 1 into 1. S 7 211 to S 3 213 encodes 1 into 10. S 3 213 to S 7 217 encodes 1 into 01. S 7 217 to S 7 217 encodes 1 into 10. S 7 217 to S 6 216 encodes 0 into 01. S 6 216 to S 4 214 encodes 0 in 00. Finally, S 4 214 to S 0 210 encodes 0 into 11. The result of this is that input information (i.e. host information from host(s) 61 - 65 ) 1111000 is encoded into error correction coded data 11100110010011 for storage in RAID 90 . In trellis diagram 300 of FIG. 7 , error correction coded data 11100110010011 is decoded to produce original information 1111000, and that is the highlighted path shown in FIG. 7 .
In FIG. 14 , encoder circuit 220 is shown for the binary (2,1,3) code of state diagram 200 of FIG. 12 and table 290 of FIG. 13 . Encoder circuit 220 may reside in specific circuits 81 of controller 80 . Alternatively, encoder 220 may be implemented external to controller 80 . Encoder circuit 220 receives input data stream U(J) 221 one bit at a time, for encoding. Encoder circuit 220 comprises an m=3-stage shift register, comprising registers 230 , 231 , and 232 . The initial contents of registers 230 - 232 are zero for the encoding process, and hence the trellis decoding process, such as illustrated in trellis diagram 300 of FIG. 7 and trellis diagram 500 of FIG. 11 , always begins and ends with state S 0 .
Referring to FIG. 14 , the input information stream U(J) 221 and the outputs of registers 230 , 231 , and 232 are selectively added by n=2 modulo-2 adders (resulting in no carryover for binary addition), comprising adder 240 to produce output V(J,1) 241 and adder 242 to produce output V(J,2) 243 . Multiplexer 251 serializes the individual encoder outputs V(J,1) 241 and V(J,2) 243 into encoded output V 250 . The modulo-2 adders may be implemented as XOR (exclusive or) gates in specific circuits 81 or alternatively by use of software, firmware, dedicated logic, etc. Because modulo-2 binary addition is a linear operation, the encoder may operate as a linear feedforward shift register. Each incremental output of V 250 for an index of J, as defined by V(J,1) and V(J,2) in FIG. 14 , is referred to as a word. Each branch of trellis diagram 300 in FIG. 7 and trellis diagram 500 of FIG. 11 represents one of these words. Thus, the trellis decoding is done with one branch representing one word, to correspond to the output of the convolution encoder being delivered one word at a time.
FIG. 15 illustrates write command 600 is an example of a SCSI write command, comprising a starting logical block address (LBA) 602 , transfer length 603 , and Logical Unit Number (LUN) 604 . LUN 604 designates to which of spare storage device, such as spare storage 97 , that the reconstructed encoded data is written by write command 600 . Starting LBA 602 indicates the first logical block address on the spare storage 97 to receive data, and transfer length 603 indicates how much data is transferred. Write command 600 maybe implemented across a SCSI or Fibre Channel interface. Write command 600 is only one possible write command which could be used. Other SCSI write commands include write plus verify, for example, where the written data is verified before the write command successfully concludes.
The embodiments described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In certain embodiments, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.
Furthermore, embodiments described herein may take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium may be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The medium may be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk, read only memory (CD-ROM), compact disk, read/write (CD-R/W) and DVD.
A data processing system suitable for storing and/or executing program code may include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements may include local memory employed during actual execution of the program code, bulk storage and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution.
Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) may be coupled to the system either directly or through intervening I/O controllers.
Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
The embodiments described herein may be implemented as a method, apparatus or computer program product using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof.
In certain embodiments, Applicant's invention includes instructions, where those instructions are executed by processor 82 ( FIG. 1 ) and/or controller 80 ( FIG. 1 ) to perform steps recited in the flowcharts shown in FIGS. 6 , 8 and 9 .
In other embodiments, Applicant's invention includes instructions residing in any other computer program product, where those instructions are executed by a computer external to or internal to, controller 80 . In either case, the instructions may be encoded in an information storage medium comprising, for example, a magnetic information storage medium, an optical information storage medium, an electronic information storage medium, and the like. By “electronic storage media,” Applicants mean, for example, a device such as a PROM, EPROM, EEPROM, Flash PROM, compact flash, smart media, and the like.
Certain embodiments may be directed toward a method for deploying computing infrastructure by a person or by an automated processing system, comprising integrating computer readable code into a system to perform the operations for the described embodiments. For example, FIGS. 6 , 8 and 9 illustrate steps for retrieving information in the form of coded data by use of the described embodiments. The code in combination with the system (i.e. SAN 10 ) is capable of performing the steps for the operation of the embodiments described herein. The deployment of the computing infrastructure may be performed during service, manufacture and/or configuration of the embodiments described herein. For example, a consulting business may have service responsibility for a number of systems. Such service responsibility may include such tasks as system upgrades, error diagnostic, performance tuning and enhancement, installation of new hardware, installation of new software, configuration with other systems, and the like. As part of this service, or as a separate service, the service personnel may configure the system according to the techniques described herein so as to efficiently enable operation of the embodiments described herein. For example, such a configuration could involve the loading into memory of computer instructions, parameters, constants (i.e. type of convolution encoding, number of bits, n in a word, stripe width, number of storage devices, etc.), interrupt vectors, so that when the code is executed, the system may carry out the techniques described to implement the embodiments described herein.
The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the embodiments described. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the operation of the embodiments. In other instances, well known circuits and devices are shown in block diagram form in order to avoid unnecessary distraction from the embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the operation of the embodiments to the precise forms disclosed. Obviously many modifications and variations are possible in view of the above teachings.
The logic of FIGS. 6 , 8 and 9 describes specific operations occurring in a particular order. In alternative implementations, certain of the logic operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described implementations. Further, operations described herein may occur sequentially or certain operations may be processed in parallel, or operations described as performed by a single process may be performed by distributed processes.
The logic of FIGS. 6 , 8 and 9 may be implemented in software. This logic may be part of the operating system of a host system or an application program. In yet further implementations, this logic may be maintained in storage areas managed by SAN 10 or in a read only memory or other hardwired type of device. The preferred logic may be implemented in hard disk drives or in programmable and non-programmable gate array logic.
Those skilled in the art of RAID may develop other embodiments equivalent to the embodiments described herein. The terms and expressions which have been employed in the foregoing specification are used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope is defined and limited only by the claims which follow.
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A Redundant Array of Independent Devices uses convolution encoding to provide redundancy of the striped data written to the devices. No parity is utilized in the convolution encoding process. Trellis decoding is used for both reading the data from the RAID and for rebuilding missing encoded data from one or more failed devices, based on a minimal, and preferably zero, Hamming distance for selecting the connected path through the trellis diagram.
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CROSS REFERENCES TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 07/891,968 filed May 26, 1992, now abandoned.
FIELD OF THE INVENTION
The instant invention relates to an improved rotary valve rotated by chain/belt or gears having designed and positioned openings in rotary driven axles to control the intake and exhaust of a reciprocating engine. The openings direct the gases to improve engine performance.
BACKGROUND OF THE INVENTION
Reciprocating piston driven engines customarily use cams and valves to control the intake and exhaust of gases. The chain/belt controlled rotary valve engine uses a simple system in which an axle is channeled with passage ways and ports and is positioned to allow access to the combustion chamber. The channeled axles eliminate the need for valves and cams and create a much simpler and more easily assembled and maintained engine. The axles can be easily removed from the head assembly. Normal engines that use valves require valve assemblies and cams to control the intake and exhaust and require many more parts that require more intricate assembly and maintenance.
The rotary nature of the valves improves fuel efficiency and horsepower. The rotary system eliminates the cam, lifters, push rods, rocker arms, valve springs, valve guides and valves. Valve problems such as valve float that limit the revolutions per minute would not occur and allow operation at higher revolutions per minute. The rotary valve system allows smaller intake and exhaust ports to produce the same horsepower as there are no obstructions to the gas flow. Should a timing chain break, unlike valves breaking or cracking, there are no parts to damage pistons. Valve timing on any engine can be more easily accomplished with the rotary valve by adjusting the angular position of the rotary valve axle.
The rotary valve system described herein allows enlarging and shaping the cross section of the port in the head assembly and thereby making the engine more efficient. The rotors are positioned horizontally to adapt to a wide range of weight and volume requirements. Due to the nature of the rotary axle opening and head assembly ports, the ports can be varied in size to adjust for timing and volume of gases resulting in better intake and exhaust performance over a wide range of engine performance parameters.
SUMMARY OF THE INVENTION
A primary objective of the present invention is to provide rotary valves with associated ports for a rotary engine which allows for ease of control of and changes to timing and volume variance depending on the requirements for an engine application. A further object of the invention is to provide a valve and port configuration that allows for a cooler running engine as compared to rotary valves that route exhaust through hollow rotary valves. Another object of the invention is to provide the valves and ports in an engine head configuration that allows for a simple head assembly using sealing rings to control the escape of gases.
In accordance with the description presented herein, other objects of this invention will become apparent when the description and drawings are reviewed.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates an expanded view of the rotary valve head assembly with one cylinder.
FIG. 2 illustrates an expanded view of the rotary valve head assembly with four cylinders.
FIG. 3 illustrates a front view of the rotary valve assembly and timing belt.
FIG. 4 illustrates a cross-sectional front view of the apparatus during the intake stroke.
FIG. 5 illustrates a cross-sectional front view of the apparatus with the ports closed for compression and firing.
FIG. 6 illustrates a cross-sectional front view of the apparatus during exhaust.
FIG. 7 illustrates a cross-sectioned front view of the apparatus during intake cycle with the intake channel and exhaust channel widened at their ports to vary timing and volume.
FIG. 8 illustrates a cross-sectioned front view of the apparatus during exhaust cycle with the intake channel and exhaust channel widened at their ports to vary timing and volume.
FIG. 9 illustrates a cross-sectioned front view of the apparatus during compression and firing.
FIG. 10 illustrates a cross-sectioned side view of the head with the intake rotary valve and the intake channel shaped.
FIG. 11 illustrates a cross-sectioned view of the head with the intake rotary valve and the intake channel shaped in an alternate configuration.
FIG. 12 illustrates a cross-sectioned view of the head with the intake rotary valve and the intake channel shaped in an alternate configuration.
FIG. 13 illustrates a cross-sectioned view of the head with the intake rotary valve and the intake channel shaped in an alternate configuration.
FIG. 14 illustrates a cross-sectioned view of the head with the intake rotary valve and the intake channel shaped in an alternate configuration.
FIG. 15 illustrates a side view of the exhaust and intake valve seals.
FIG. 16 illustrates an end view of the exhaust and intake valve seals.
FIG. 17 illustrates the "O" ring.
FIG. 18 illustrates a side view of the "O" ring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although any number of pistons and any orientation of each piston is feasible, a single cylinder engine and four cylinder engine are shown in FIGS. 1 and 2. Referring to FIGS. 1 through 6, the rotary valve reciprocating chain/belt controlled engine is shown. The rotary valve assembly consists of two channeled axles called rotary valves (4,5), timing chain (17), spark plug (14) and valve head (1,2). The intake rotary valve (4) controls the intake of the fuel and the exhaust rotary valve (5) controls exhausting the gases after combustion. FIGS. 4 through 6 illustrate the cycles of a gasoline or Diesel engine. The intake rotary valve (4) and exhaust rotary valve (5) turn the same number of revolutions as a similar cam activated system but there is no requirement for cams, lifters, rocker arms, push rods, valves, valve springs or valve guides. The rotary valves (4,5) turn one half revolution per every turn of the crankshaft. Referring to FIG. 4 as the intake rotary valve (4) is turned, the intake port (16) and the intake channel (7) which is within the intake rotary valve (4) align and an opening is created between the intake port (16) and the combustion chamber (3) above the piston (18). There is no obstruction to the flow of gases, such as a valve guide, valve stem or valve head used in a cam driven system. On completion of the intake cycle the intake channel (7) is no longer aligned with the intake port (16) and the combustion chamber (3) is sealed as shown in FIG. 5. FIG. 6 shows that after the piston (18) is positioned at the appropriate time and the combustion complete, the exhaust channel (6) within the exhaust rotary valve (5) aligns between the exhaust port (15) and the combustion chamber (3) and the gases under pressure are expelled. The timing of events is controlled by the rotation of the rotary valves (4, 5) and timing chain (17).
The horsepower that is required to turn the rotary valves (4, 5) are considerably less then the horsepower required to turn the cam and operate all the components of a cam driven valve system. The rotary valves (4, 5) can be designed to turn and operate the same as any dual overhead cam engine.
The intake channel (7), intake rotor port (30) and intake rotor cylinder port (31) as well as the exhaust channel (6), exhaust rotor port (32) and exhaust rotor cylinder port (33) can be elongated circumferentially as shown in FIGS. 7 through 9 to duplicate any valve timing openings and closings desired. The intake port (16), exhaust port (15), cylinder intake port (23) and cylinder exhaust port (24) may also be similarly varied in size. The same elements may also be varied in size in the axial direction of the intake rotary valve (4) and exhaust rotary valve (5) to accommodate the optimum volume of intake or exhaust gases to produce the greatest horsepower or efficiency as required.
The intake channel (7) and exhaust channel (6) are channeled such that their ports (30, 31, 32, 33) open at different points axially along the rotary valves (4, 5). This allows for timing and sealing options such that for example the intake rotor port (30) passes over the intake port (16) but not the cylinder intake port (23).
The duration of maximum port opening time, coupled with the rotor passageways, may be made considerably longer in duration than that of a normal existing valve maximum opening time. Normal existing cam actuated valves are limited by the shape of the cam and of the valve spring where as the instant invention has no such limitation and many arrangements of both port and passageway sizes and shapes may be used.
Referring more specifically to FIG. 7 as the intake rotary valve (4) is turned, the intake port (16) and the intake channel (7) which is within the intake rotary valve (4) align and an opening is created between the intake port (16) in the head and the cylinder intake port (23) passing into the combustion chamber (3) above piston (18). To ensure proper flow of intake gases and provide for combustion, intake seals (20) must be installed. To ensure pressure of the seals to the rotary shaft an "O" ring (21) or equivalent may be used. For the exhaust a similar seal arrangement using exhaust seals (19) is required.
Referring to FIGS. 10-14, the intake port (16) shape is shown superimposed on the intake rotor port (30). Referring to FIG. 10, a typical intake port (16) shape is shown round and the combustion port (23) has the same configuration. The intake channel (7), being the same width as the ports (16) and (23), is shown with an axial offset to provide proper sealing and the intake channel (7), intake rotor port (30) and intake rotor cylinder port (31) are shown elongated circumferentially to match the timing of valve opening and closing. Spring washers (25) and (26) are required to ensure proper end play clearance for rotary valve (4).
Referring to FIG. 11, a typical intake port (16) shape is shown elongate axially relative to the intake rotary valve (4) to increase the required volume compared to FIG. 10 and a cylinder intake port (23) being the same configuration. The intake channel (7) and its ports (30, 31), being the same width as the head ports (16) and (23), is shown with an offset to provide proper timing and sealing. Spring washers or equivalent (25) and (26) are required to ensure proper end play clearance, for rotary valve (4).
Referring to FIG. 12, a typical intake port (16) shape is shown narrowed axially to reduce the required volume compared to FIG. 10, and a combustion port (23) being the same configuration. The intake channel (7) is the same width as the ports (16) and (23) and is shown with an offset to provide proper timing and sealing and the channel (7) is shown as being elongated circumferentially to match opening and closing valve timing. Spring washers or equivalent (25) and (26) are required to ensure proper end play clearance for rotary valve (4).
Referring to FIG. 13, a typical intake port (16) shape is shown as being widened horizontally to a rectangular configuration to produce an increase in the required volume if space or area is a problem compared to FIG. 10, and a combustion port (23) being the same configuration. The intake channel (7), being the same width as the ports (16) and (23), is shown with an offset to provide proper timing and sealing and the channel (7) is shown as being elongated circumferentially to match opening and closing valve timing. Spring washers or equivalent (25) and (26) are required to ensure proper end play clearance for rotary valve (4).
Referring to FIG. 14, a typical intake port (16) shape and cylinder intake port (23) is shown elongated circumferentially relative to intake rotary valve (4). Such elongation allows the valve to open earlier and close later, either one or both, depending on which end is elongated. If the leading edge of the ports (16) and (23) when compared to the rotation of intake rotary valve (4) are elongated the valve opens sooner. If the trailing edge of the ports (16) and (23) are elongated the valve closes later. The above change may also be accomplished by elongating circumferentially the intake channel (7) ports (30, 31), at both ends, in intake rotary valve (4). The intake channel (7), being the same width as the ports (16) and (23), is shown with an offset to provide proper timing and sealing and the intake channel (7) is shown as elongated circumferentially to match opening and closing valve timing. Spring washers or equivalent (25) and (26) are required to ensure proper end play clearance for rotary valve (4).
Referring to FIG. 9, the intake and exhaust rotary valves (4, 5) are shown with no opening aligning with ports passing into the combustion chamber (3). During this time the fuel and air are compressed and the mixture ignited.
Referring to FIG. 8, as the exhaust rotary valve (5) is turned, the exhaust port (15) and the exhaust channel (6) which is within the exhaust rotary valve (5) align and an opening is created between the exhaust port (15) in the head and the cylinder exhaust port (24) passing to combustion chamber (3) above piston (18). To ensure proper flow of exhaust gases and provide for combustion, seals (19) must be installed. To provide pressure of the seals to the rotary shaft an "O" ring (21) or equivalent must be used.
Referring to FIGS. 15 through 18, an end view and a side view is shown of a typical seal and "O" ring to be used at each head port for intake and exhaust. The use of such seals provides for ease of engine assembly as special machining is not required to prevent escape of gases.
Material for the intake and exhaust seals should be similar to Teflon or equivalent. Material for the "O" ring should be similar to Buna-N or equivalent.
Referring to FIGS. 1 and 2, at the forward end of the intake rotary valve (4) and the exhaust rotary valve (5) are the intake valve forward bearing (10) and exhaust valve forward bearing (11), respectively. At the rear of the intake rotary valve (4) and exhaust rotary valve (5) are the intake valve rear bearing (9) and the exhaust valve rear bearing (8), respectively. The cavities (34) and (35) for the bearings retain the bearings in the head assembly. On the forward end of the intake rotary valve (4) is an intake rotary valve chain driven sprocket (12). On the forward end of the exhaust rotary valve (5) is an exhaust valve chain driven sprocket (13). The intake and exhaust valve chain driven sprockets (12, 13) are fixed to the rotary valves (4, 5) and in cooperation with the timing chain (17) control the opening and closing of the valves (4, 5).
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An improved rotary valve assembly that is rotated by chain, belt or gears that are driven by a reciprocating engine which has intake and exhaust rotary valves that have ports and interior channels that are sequentially positioned to allow the intake and exhaust of gases and alternatively seals the combustion chamber. The rotary valve ports and intake and exhaust ports may be varied axially and circumferential to change the engine time and gas volume capacity of the engine.
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TECHNICAL FIELD
[0001] The present disclosure relates to a sealable structure to enclose a high voltage battery pack used in an electrified vehicle.
BACKGROUND
[0002] The battery pack of a hybrid electric vehicle is generally rated at 60 volts or above. To achieve the overall battery voltage, the battery consists of multiple lower voltage individual battery cells connected in series to produce the overall battery voltage. Along with the series connection, the battery may consist of multiple groups of batteries connected in parallel to achieve the current and energy requirements for use in the vehicle. The electrical energy in such a battery pack may receive a charge from a generator or an electrical connection to the utility grid, or the battery may deliver a charge to an electric motor, a traction motor, or electrical vehicular accessories. Typically such battery packs also include systems to monitor and control the individual battery cell's condition and operation, including its state of charge, its temperature, its voltage, as well as high-voltage contactors and bus bars for charging and discharging the battery pack.
[0003] To achieve the vehicular energy storage requirements, the use of batteries with higher power density employing advanced battery chemistries are often used. The use of the advanced batteries chemistries requires additional considerations to contain and enclose the battery cells. One consideration is that as a by-product of the battery charging and discharging, the battery may produce gases, liquids and solids during the process. It is important to contain and protect the vehicle and passengers from resulting chemical by-products. Also, these advanced batteries may have an appreciable mass which needs to be contained and secured. It is desirable to have access to the cells for service and maintenance.
SUMMARY
[0004] A battery used in a hybrid electric vehicle may contain multiple individual battery cells, that when combined, produce the energy and voltage necessary for the operation of the vehicle. The battery is generally contained in a battery enclosure which is able to be sealed and also able to be opened and accessed to allow for maintenance and refurbishing. The use of a lid which is oriented at a diagonal, and yet contained in a single plane, may provide for improved accessibility. A bulkhead which provides for suitable electrical and thermal connections to the vehicle may also be included.
[0005] Here, a fraction battery assembly is described which comprises a tray and a cover. The tray may include a base having at least one wall extending from the base. The at least one wall may define a continuous planar mounting surface around a perimeter of the tray and that is disposed at an angle relative to the base. The cover may be configured to mount against the planar mounting surface, and a plurality of battery cells may be electrically connected and surrounded by the tray and cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates a representation of a vehicle with a battery subsystem in which the battery enclosure has a planar sealing surface that intersects the base plane;
[0007] FIG. 2 illustrates a side view of a battery enclosure in which the seam is confined to a single plane and the seam plane generally intersects the top or bottom enclosure plane;
[0008] FIG. 3 illustrates an exploded view of a battery enclosure in which the seam is confined to a single plane and the seam plane generally intersects the top or bottom enclosure plane;
[0009] FIG. 4 illustrates an exploded view of a battery enclosure in which the battery enclosure has a planar sealing surface which intersects the base plane such that the enclosure walls are rotated with respect to an axis;
[0010] FIG. 5 a illustrates a side view of a cylindrical battery enclosure in which the battery enclosure has a planar sealing surface which intersects the base plane and the cover has contoured surface;
[0011] FIG. 5 b illustrates an aspect view of a cylinder battery enclosure in which the battery enclosure has a planar sealing surface which intersects the base plane and the cover has contoured surface; and
[0012] FIG. 6 illustrates a representation of a T-shaped battery enclosure in which the seam is confined to a parabolic plane.
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] Vehicle electricity demand has increased, driving the need to supply voltage and current to satisfy the demand. This electricity demand may be for propulsion and for powering accessories. The need for voltage and current in conjunction with vehicle propulsion is especially prevalent in hybrid electric vehicles and vehicles equipped with stop-start technology. This need may be met by increasing the size of the battery. Battery chemistries that provide greater charge densities may be utilized. Due to the vehicle size constraints, engineers are challenged with packaging battery systems in a variety of vehicle models that have a corresponding variety of space available in which to place the battery system.
[0015] FIG. 1 depicts an example of a plug-in hybrid-electric vehicle. A plug-in hybrid-electric vehicle 102 may comprise one or more electric motors 104 mechanically connected to a hybrid transmission 106 . In addition, the hybrid transmission 106 is mechanically connected to an engine 108 . The hybrid transmission 106 may also be mechanically connected to a drive shaft 110 that is mechanically connected to the wheels 112 . The electric motors 104 can provide propulsion when the engine 108 is turned on. The electric motors 104 can provide deceleration capability when the engine 108 is decoupled. The electric motors 104 may be configured as generators and can provide fuel economy benefits by recovering energy that would normally be lost as heat in the friction braking system. The electric motors 104 may also reduce pollutant emissions since the hybrid electric vehicle 102 may be operated in electric mode under certain conditions.
[0016] The battery pack 114 stores energy that can be used by the electric motors 104 . A vehicle battery pack 114 typically provides a high voltage DC output. The battery pack 114 is electrically connected to a power electronics module 116 . The power electronics module 116 is also electrically connected to the electric motors 104 and provides the ability to bi-directionally transfer energy between the battery pack 114 and the electric motors 104 . For example, a typical battery pack 114 may provide a DC voltage while the electric motors 104 may require a three-phase AC current to function. The power electronics module 116 may convert the DC voltage to a three-phase AC current as required by the electric motors 104 . In a regenerative mode, the power electronics module 116 will convert the three-phase AC current from the electric motors 104 acting as generators to the DC voltage required by the battery pack 114 . The methods described herein are equally applicable to a pure electric vehicle or any other device using a battery pack.
[0017] In addition to providing energy for propulsion, the battery pack 114 may provide energy for other vehicle electrical systems. A typical system may include a DC/DC converter module 118 that converts the high voltage DC output of the battery pack 114 to a low voltage DC supply that is compatible with other vehicle loads. Other high voltage loads, such as compressors and electric heaters, may be connected directly to the high-voltage bus from the battery pack 114 . In a typical vehicle, the low voltage systems are electrically connected to a 12V battery 120 . An all-electric vehicle may have a similar architecture but without the engine 108 .
[0018] The battery pack 114 may be recharged by an external power source 126 . The external power source 126 may provide AC or DC power to the vehicle 102 by electrically connecting through a charge port 124 . The charge port 124 may be any type of port configured to transfer power from the external power source 126 to the vehicle 102 . The charge port 124 may be electrically connected to a power conversion module 122 . The power conversion module may condition the power from the external power source 126 to provide the proper voltage and current levels to the battery pack 114 . In some applications, the external power source 126 may be configured to provide the proper voltage and current levels to the battery pack 114 and the power conversion module 122 may not be necessary. The functions of the power conversion module 122 may reside in the external power source 126 in some applications.
[0019] In addition to illustrating a plug-in hybrid vehicle, FIG. 1 can illustrate a battery electric vehicle (BEV) if components 108 , 122 , 124 , and 126 are removed. Likewise, FIG. 1 can illustrate a traditional hybrid electric vehicle (HEV) or a power-split hybrid electric vehicle if components 122 , 124 , and 126 are removed.
[0020] A battery system typically comprises a plurality of electrochemical cells. These cells may be independent from each other so that when servicing or refurbishing a battery, an individual defective cell may be removed and replaced. The electrochemical cells can rupture if subjected to improper operating conditions. In the event that the battery cells rupture, the cells may release liquids, gases, or solids along with heat and pressure. It may be desirable to contain or direct release of the gases and/or other emissions within the enclosure in the event of a rupture or vent. The distinction between rupture and vent is that a rupture is an uncontrolled release of cell material and a vent is a controlled release of cell material.
[0021] As battery needs change to address the size, shape, weight and charge densities required by the vehicle, the efficient use of available space and different battery chemistries becomes more critical. Due to the potential types of battery chemistries and the possible different locations where the battery may reside in the vehicle, the need for the enclosure to seal the contents becomes more important. Some batteries may require a seal to maintain a liquid and/or gas tight boundary between the inside of the enclosure and the outside of the enclosure.
[0022] A battery may be located in multiple locations in a vehicle. If the battery is mounted outside of the passenger compartment, it is desired that the enclosure protect the interior battery cells from water, contaminants and the elements. If the battery is mounted within the passenger compartment, it is desired to protect the exterior of the battery from any liquid, gas or solid material generated as a by-product of the battery operation or in the event of a battery failure.
[0023] Along with physical emissions of gasses, liquids and/or solids, a battery may also generate heat during operation. Some battery chemistries, however, may be more efficient when operating within a specific temperature range. Liquids may thus be used to cool (or heat) the battery such that an optimal temperature range of operation is maintained during operation. To facilitate this, the enclosure may be required to maintain or keep the liquid coolant inside the enclosure and the liquid coolant may pass through a seal. The coolant may circulate inside the enclosure and then through the seal to the exterior where the coolant may be returned to the optimal temperature to maintain the desired operational range. Although it is typically not desirable to have the liquid free-flowing on the battery and contents inside the enclosure, there are exceptions to this such as when a liquid is used that is in direct contact with the battery cells and contents inside the enclosure. The temperature control may also be accomplished by the use of a gas such as air.
[0024] When using a gas to thermally control the battery temperature, it may still be important that the battery cells are not exposed to any moisture, humidity or water. The gas regulated battery system may require a seal so that the integrity of a closed loop gas system can be maintained. A concern of this system is that the change in pressure inside the enclosure needs to be regulated. The regulation may be accomplished by the use of a vent or channel to transmit the gas from the battery to the vehicle exterior and away from the cabin interior.
[0025] FIG. 2 is a side view of a battery enclosure 200 that comprises a lower section or tray 202 and a top section or cover 204 . The tray 202 and cover 204 join together at a seam 206 . The tray 202 generally resides on a plane 208 . The seam 206 generally resides on a plane 210 , where the planes are not parallel but intersect at a line 212 . The seam plane 210 can generally be expressed as z=mx+b for all values of y. The tray 202 has a rear wall 214 with a rear wall height of H and a front wall 216 with a reduced height. The intersection point 212 may be determined to maximize the rear wall 214 with respect to the front wall 216 while allowing for a flange 218 , which provides for a sealing surface, and the tray 202 to rest flush on the base plane 208 . A sealing surface that is confined to a single plane eliminates transitions and improves the reliability and manufacturability of the battery enclosure 200 . For battery manufacturers, transitions in the battery cover are more difficult to seal properly. When the transitions go from a vertical wall to a horizontal wall, this increases the difficultly with achieving a quality seal in both directions because compression requirements for such a transition may occur in both vertical and horizontal directions. Here, the force to seal the enclosure can be limited to a single direction. The fasteners 220 may be mounted perpendicular to the seam plane 210 reducing shear stress. The fasteners 220 also may be mounted perpendicular to the base plane 208 —either way the force to seal the enclosure 200 is in a single direction. If the fasteners 220 apply force perpendicular to the base plane 208 , shear stress is added to the sealing seam 206 in addition to the compression force. Fasteners applying force perpendicular to the base plane 208 would typically be less desirable for the seal 206 , but more desirable for the fastener assembly.
[0026] FIG. 3 is an exploded view of a battery assembly 300 comprising a battery enclosure 200 that encases the battery pack 302 . The battery pack 302 comprises battery cells 304 , mechanical and electrical interconnects 306 , electronics 308 and thermal paths 310 . This battery enclosure 200 is a solution to the sealing problems presented for both a liquid thermally regulated battery system and a gas thermally regulated battery system. The enclosure of FIG. 3 has a battery sealing surface 312 that is inclined with respect to the base plane 208 and forms a continuous sealing surface 314 on a single plane. The base plane 208 is at z=0 for all values of x and y. The planar sealing surface 314 or the mounting surface is contained on a sealing plane 210 that can be expressed as z=mx+b for all values of y. The enclosure is generally a rectangular prism shape which can encapsulate a rectangularly shaped volume. This rectangular battery container has four walls: a back wall 214 , a front wall 216 and two transition or side walls 322 and 324 . In this illustration, the back wall height is shown to be z=H, and the front wall height is less than H. The reduced height of the front wall 216 allows the battery cells 304 to be accessed from two directions, the z direction 326 and the x direction 328 . This two dimensional access makes assembling and servicing the battery easier. The mounting or sealing surface 312 is also confined to a single plane 210 . Confining the mounting surface to a single plane 210 in which the sealing surface 312 does not include any breaks produces a continuous planar mounting surface 314 . This continuous mounting surface 314 allows a variety of sealing methods to be used. The methods of sealing include, but are not limited to, gasket, O-ring, foam, and silicon bead. Because the planar seam 312 is confined to a single plane 210 , the force applied to seal the enclosure 330 is in a single direction. The direction of force to seal the enclosure 330 is generally perpendicular to the sealing plane 210 , but that may include instances in which the force is applied perpendicular to the base plane 208 of the enclosure 330 .
[0027] Another advantage is that the back or high wall 214 can be configured to have an access panel 330 . The access panel 330 can be used to allow an electrical connection or conduit through which electricity or thermal energy can be transported. The advantage is that this connection or conduit can be sealed with the battery tray by a more permanent method as the access panel 330 may be opened much less frequently than the enclosure 200 .
[0028] FIG. 4 is an exploded view of an example of an embodiment in which the continuous planar sealing surface 400 can be expressed as z=mx+b. In this example, the battery enclosures comprises of a lid or cover 402 and a tray or base 404 . The tray 404 has an access opening 406 to allow for an electrical connection or conduit through which electricity or thermal energy can be transferred. The battery enclosure is rotated such that the walls of the enclosure 408 are not parallel to one of the coordinate axis. The battery enclosure is rotated by a number of degrees 410 . The combination of the rotation 410 and the inclined planar sealing surface 400 results in a corner with a lowest height 412 .
[0029] FIG. 5 a is side view of an example of an implementation in which the continuous planar sealing surface 500 can also be expressed as z=mx+b. In this example as in others, an enclosure cover 502 does not reside on a single plane but instead may have multiple contours so that the cavity formed can meet the volume and shape needs of the battery system enclosed. In this example, the battery cover 502 generally resides on three planes in which the three planes are illustrated as A-plane 504 , B-plane 506 and C-plane 508 . The A-plane 504 may be expressed as y=A for all values of x and z. The B-plane 506 may be expressed as y=B for all values of x and z. The C-plane 508 may be expressed as y=mx+b for all values of z. FIG. 5 b is an aspect view of a cylinder battery enclosure 510 with a contoured cover 502 and a continuous sealing surface 500 .
[0030] FIG. 6 is an aspect view of a T-shaped battery enclosure 610 with a contoured cover 602 and a continuous sealing surface 600 .
[0031] To meet the volume and shape needs of the battery system enclosed, the battery enclosure may have multiple contours so that the cavity formed can meet the volume and shape needs of the battery system enclosed. This may result in the battery enclosure taking the shape of a cylinder, T , L, etc. Also to maximize accessibility, the use of a non-flat plane such as but not limited to a parabolic plane or hyperbolic plane may be used to define the sealing surface such that the surface does not contain any transitions or edges. A smooth parabolic plane or hyperbolic plane sealing surface that eliminates the transitions will improve reliability and manufacturability of the battery enclosure. For battery manufacturers, transitions in the battery cover are more difficult to seal properly. A parabolic plane or hyperbolic plane sealing surface will have a single direction that force can be applied to provide a seal across the entire sealing surface.
[0032] 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.
[0033] 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.
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A battery assembly for an electrified vehicle is disclosed, the battery assembly includes a battery cover and a battery tray that join at a single continuous planar sealing surface around a perimeter of the assembly. The continuous planar sealing surface is disposed at an angle relative to the base.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the oral delivery of parathyroid hormone (PTH). More particularly, the invention is directed to the use of calcitonin in combination with PTH for the oral administration of PTH.
[0003] 2. Description of the Related Art
[0004] PTH studies done in animals and humans with PTH, PTH-related peptides, and PTH analogs have demonstrated its usefulness in increasing bone formation and bone resorption and have prompted interest in its use for the treatment of osteoporosis and related bone disorders. However, the clinical utility of PTH is limited by the occurrence of hypercalcemia, hypercalcuria and nephrolithiasis. The occurrence of these potentially toxic side effects and alterations in calcium metabolism have remained an obstacle to exploiting the benefits of higher dosages of PTH and have required, for safety concerns, that plasma concentrations of the PTH remain within a narrow band. If the hypercalcemic effects, largely mediated by osteoclasts, could be separated from the bone formative effects, largely mediated by osteoblasts, then the therapeutic window for oral PTH therapy could be increased. In contrast to PTH, calcitonins reduce serum calcium concentrations by interacting directly with osteoclasts resulting in reduction in the bone resorptive surface area by osteoclasts and reduction in net bone resorption. Due to a decrease in plasma calcium concentration there is a corresponding decrease in urinary calcium concentrations, a known risk factor for nephrolithiasis. The present invention describes a method for orally administering PTH which broadens the therapeutic window for PTH administration and allows for the oral administration of greater PTH dosages without the potentially toxic hypercalcemic side effects.
SUMMARY OF THE INVENTION
[0005] Accordingly, the present invention is directed to a method for orally administering an effective dose of PTH comprising orally co-administering to a patient in need of PTH an effective amount of a PTH and an effective amount of a calcitonin.
[0006] Administration of PTH to primates results in increased plasma concentrations of serum parathyroid hormone and serum calcium. Conversely the administration of salmon calcitonin (sCT) to primates results is an increase in serum sCT concentrations and a reduction in serum calcium. It has now been found that the oral administration of a combination of PTH and calcitonin, while resulting in similar PTH and calcitonin plasma concentration levels as those attained upon administrations of each agent alone; quite surprisingly results in reduction of serum calcium concentrations to the level observed with calcitonin alone. In effect, the calcitonin negates the hypercalcemic effect of the PTH while attaining the same reduction in serum calcium obtained when calcitonin is administered alone, in the absence of PTH. Administering calcitonin with PTH therapy allows the additional therapeutic effects of the presently precluded PTH doses without the hypercalcemic side effects. Additionally, the calcitonin provides an analgesic effect which is useful in off-setting the bone pain usually associated with administration of PTH.
[0007] The invention is also directed to a method of stimulating new bone formation comprising orally administering to a patient in need of new bone formation a therapeutically effective amount of a PTH and a therapeutically effective amount of a calcitonin.
[0008] In a further embodiment, the invention is directed to a method of treatment or prevention of osteoporosis comprising orally administering to a patient in need of said treatment or prevention a therapeutically effective amount of a PTH and a therapeutically effective amount of a calcitonin.
[0009] The invention is also directed to a composition suitable for oral delivery comprising a PTH and a calcitonin, e.g. for simultaneous, concurrent or sequential administration of the PTH and calcitonin.
[0010] The invention is further directed to use of PTH and calcitonin for the preparation of an orally administrable medicament for the stimulation of new bone formation, e.g. for simultaneous, concurrent or sequential oral administration of the PTH and calcitonin.
[0011] The invention is yet further directed to a kit for the stimulation of new bone formation comprising PTH and calcitonin suitable for oral administration together with instructions for the oral administration thereof, e.g. for simultaneous, concurrent or sequential oral administration of the PTH and calcitonin.
[0012] Further features and advantages of the invention will become apparent from the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The parathyroid hormone or PTH can be the full length, 84 amino acid form of parathyroid hormone, e.g. the human form, hPTH (1-84), or any polypeptide, protein, protein fragment, or modified fragment, i.e. PTH-related peptides and PTH analogs, capable of mimicing the activity of hPTH (1-84) in controlling calcium and phosphate metabolism to build bone in the human body. The PTH fragments will generally incorporate at least the first 28 N-terminal residue and include PTH (1-28), PTH (1-31), PTH (1-34), PTH (1-37), PTH (1-38) and PTH (1-41) or analogues thereof, e.g. PTS893. The PTH can be a single PTH or any combination of two or more PTHs. These parathyroid hormones are commercially available or can be obtained recombinantly, by peptide synthesis, or by extraction from human fluid by methods well established in the art.
[0014] The calcitonin for use in the instant invention can be any calcitonin, including natural, synthetic or recombinant sources thereof, as well as calcitonin derivatives such as 1,7-Asn-eel calcitonin. Various calcitonins, including salmon, pig and eel calcitonin are commercially available and commonly employed for the treatment of e.g. Paget's disease, hypercalcemia of malignancy and osteoporosis. The calcitonin can comprise a single calcitonin or any combination of two or more calcitonins. The preferred calcitonin is synthetic salmon calcitonin.
[0015] The calcitonins are commercially available or may be obtained by known methods.
[0016] The amount of PTH to be administered is generally an amount effective to stimulate new bone formation i.e. a therapeutically effective amount. This amount will necessarily vary with the age, size, sex and condition of the subject to be treated, the nature and severity of the disorder to be treated and the like. However, the amount can be less than that amount when a plurality of the compositions are to be administered, i.e., the total effective amount can be administered in cumulative dosage units. The amount of PTH can also be more than the effective amount when the composition provides sustained release of the pharmacologically active agent. The total amount of PTH to be used can be determined by methods known to those skilled in the art. However, in general, satisfactory results will be obtained systemically at daily dosages of from about 0.001 μg/kg to about 10 mg/kg animal body weight, preferably 1 μg/kg to about 6 μg/kg body weight.
[0017] The appropriate dosage of calcitonin to be administered will, of course, vary depending upon, for example, the amount of PTH to be administered and the severity of the condition being treated. However, in general, satisfactory results will be obtained systemically at daily dosages of from about 0.5 μg/kg to about 10 μg/kg animal body weight, preferably 1 μg/kg to about 6 μg/kg body weight.
[0018] The oral administration can be accomplished regularly, e.g. once or more on a daily or weekly basis; intermittently, e.g. irregularly during a day or week; or cyclically, e.g. regularly for a period of days or weeks followed by a period without administration.
[0019] The co-administration of PTH and calcitonin includes simultaneous, concurrent, or sequential administration of the two compounds. Simultaneous administration means administration of the two compounds in a single dosage form; concurrent administration means administration of the two compounds at about the same time but in separate dosage forms; and, sequential administration means administration of one of the compounds, after which the other is administered. Sequential administration may also take the form of simultaneous or concurrent administration of the two compounds, followed by cessation of the simultaneous or concurrent administration and then continued administration of one of the two compounds alone.
[0020] The oral administration of the PTH and calcitonin according to the instant invention can be accomplished in any known manner, e.g. as a liquid or solid dosage forms.
[0021] The liquid dosage forms include solution emulsions, suspensions, syrups and elixirs. In addition to the PTH and/or calcitonin, the liquid formulations may also include inert excipients commonly used in the art such as, solubilizing agents such as ethanol; oils such as cottonseed, castor and sesame oils; wetting agents; emulsifying agents; suspending agents; sweeteners; flavorings; and solvent such as water.
[0022] The solid dosage forms include capsules, soft-gel capsules, tablets, caplets, powders, granules or other solid oral dosage forms, all of which can be prepared by methods well known in the art. In addition to the PTH and/or calcitonin, these solid dosage forms generally include a pharmaceutically acceptable delivery agent for the PTH and/or calcitonin.
[0023] Suitable delivery agents are any one of the 123 modified amino acids disclosed in U.S. Pat. No. 5,866,536 or any one of the 193 modified amino acids described in U.S. Pat. No. 5,773,647 or any combination thereof. The contents of the aforementioned U.S. Pat. Nos. 5,773,647 and 5,866,536 are hereby incorporated by reference in their entirety. In addition, the delivery agent can be the disodium salt of any of the aforementioned modified amino acids as well as ethanol solvates and hydrates thereof. Suitable compounds include compounds of the following formula I
[0024] wherein
[0025] R 1 , R 2 , R 3 , and R 4 are independently hydrogen, —OH, —NR 6 R 7 , halogen, C 1 -C 4 alkyl, or C 1 -C 4 alkoxy;
[0026] R 5 is a substituted or unsubstituted C 2 -C 16 alkylene, substituted or unsubstituted C 2 -C 16 alkenylene, substituted or unsubstituted C 1 -C 12 alkyl(arylene), or substituted or unsubstituted aryl(C 1 -C 12 alkylene); and
[0027] R 6 and R 7 are independently hydrogen, oxygen, or C 1 -C 4 alkyl; and hydrates and alcohol solvates thereof. The compounds of formula I as well as their disodium salts and alcohol solvates and hydrates thereof are described in WO 00/059863, along with methods for preparing them.
[0028] The preferred delivery agents are N-(5-chlorosalicyloyl)-8-aminocaprylic acid (5-CNAC), N-(10-[2-hydroxybenzoyl]amino)decanoic acid (SNAD), N-(8-[2-hydroxybenzoyl]amino)caprylic acid (SNAC) and their monosodium and disodium salts, ethanol solvates of their sodium salts and the monohydrates of their sodium salts and any combinations thereof. The most preferred delivery agent is the disodium salt of 5-CNAC and the monohydrate thereof.
[0029] The pharmaceutical compositions of the present invention typically contain a delivery effective amount of one or more of the delivery agents, i.e. an amount sufficient to deliver the PTH and/or calcitonin for the desired effect. Generally, the delivery agent is present in an amount of 2.5% to 99.4% by weight, more preferably 25% to 50% by weight of the total composition.
[0030] The compositions may additionally comprise additives in amounts customarily employed including, but not limited to, a pH adjuster, a preservative, a flavorant, a taste-masking agent, a fragrance, a humectant, a tonicifier, a colorant, a surfactant, a plasticizer, a lubricant such as magnesium stearate, a flow aid, a compression aid, a solubilizer, an excipient, a diluent such as microcrystalline cellulose, e.g. Avicel PH 102 supplied by FMC corporation, or any combination thereof. Other additives may include phosphate buffer salts, citric acid, glycols, and other dispersing agents.
[0031] The composition may also include one or more enzyme inhibitors, such as actinonin or epiactinonin and derivatives thereof; aprotinin, Trasylol and Bowman-Birk inhibitor.
[0032] Further, a transport inhibitor, i.e. a ρ-glycoprotein such as Ketoprofin, may be present in the compositions of the present invention.
[0033] The solid pharmaceutical compositions of the instant invention can be prepared by conventional methods e.g. by blending a mixture of the active agent or active agents, the delivery agent, and any other ingredients, kneading, and filling into capsules or, instead of filling into capsules, molding followed by further tableting or compression-molding to give tablets. In addition, a solid dispersion may be formed by known methods followed by further processing to form a tablet or capsule.
[0034] Preferably, the ingredients in the pharmaceutical compositions of the instant invention are homogeneously or uniformly mixed throughout the solid dosage form.
[0035] The oral administration of the present invention may be to any animal in need thereof, including, but not limited to, mammals, such as rodents, cows, pigs, dogs, cats, and primates, particularly humans.
[0036] The following examples serve to further illustrate the invention.
EXAMPLE 1
[0037] The following capsules are prepared as follows:
[0038] Capsules prepared from 400 mg 5-CNAC disodium salt/800 mcg sCT/800 mcg PTH (Capsule 1A)
[0039] Capsules prepared from 400 mg 5-CNAC disodium salt/800 mcg PTH (Capsule 1B)
[0040] Capsules prepared from 400 mg 5-CNAC disodium salt/800 mcg sCT (Capsule 1C)
[0041] Capsules prepared from 800 mcg PTH (Capsule 1D)
[0042] The PTH is PTH fragment 1-34, commercially available. The sCT is salmon calcitonin. The capsules are all prepared as dry blends by weighing out the individual components blending them together to make a homogeneous mix and then hand filling 400 mg of the mix into each capsule. For the PTH only capsules, the PTH is weighed out and 400 mg placed directly into each capsule.
EXAMPLE 2
Primate Administration
[0043] The capsules prepared in Example 1 are administered to Rhesus monkeys as follows: four monkeys in a group are each dosed with one capsule prepared as in Example 1 as follows:
[0044] The Rhesus monkeys fast overnight prior to dosing and are restrained in chairs fully conscious, for the duration of the study period. The capsules are administered via a gavage tube followed by 10 mL of water.
[0045] Blood samples are collected at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, and 6 hours after administration. Plasma salmon calcitonin and plasma PTH are determined by radioimmunoassay. The primate plasma salmon calcitonin (sCT) and PTH results from each group of monkeys are averaged and the maximum mean plasma calcitonin are calculated and reported in Tables 1-5
TABLE 1 SALMON CALCITONIN and PTH SCT PLASMA CONCENTRATIONS (pg/mL) AFTER ORAL ADMINISTRATION TO THE RHESUS MONKEY Dose: 1 Capsule 1A Animal Time [hours] no. 0 0.25 0.50 0.75 1 1.5 2 3 4 5 6 S961 0 27 39 54 49 39 26 12 0 0 0 S983 0 386 747 628 774 802 811 305 174 36 0 S985 0 470 502 603 648 634 521 204 73 40 32 E56 0 251 270 273 246 171 124 49 19 0 11 Mean 0 284 389 389 429 411 370 143 66 19 11 SD 0 194 304 276 339 365 364 137 78 22 15 SEM 0 97 152 138 170 182 182 68 39 11 8
[0046] [0046] TABLE 2 SALMON CALCITONIN and PTH PTH PLASMA CONCENTRATIONS (pg/mL) AFTER ORAL ADMINISTRATION TO THE RHESUS MONKEY Dose: 1 Capsule 1A Animal Time [hours] no. 0 0.25 0.50 0.75 1 1.5 2 3 4 5 6 S961 0 0 0 26 27 28 0 0 0 0 0 S983 0 175 309 181 202 226 213 75 34 0 0 S985 0 133 206 261 299 252 175 75 29 0 0 E56 0 89 124 158 144 105 90 61 35 28 0 Mean 0 99 160 156 168 153 119 53 25 7 0 SD 0 75 131 98 113 105 95 36 17 14 0 SEM 0 37 65 49 57 52 47 18 8 7 0
[0047] [0047] TABLE 3 SALMON CALCITONIN CALCIUM PLASMA CONCENTRATIONS (pg/mL) AFTER ORAL ADMINISTRATION TO THE RHESUS MONKEY Dose: 1 Capsule 1C Animal Time [hours] no. 0 1 2 3 4 5 6 R944 0.00 −3.08 −6.54 −8.99 −13.89 −12.88 −13.75 S966 0.00 −9.74 −17.30 −23.43 −24.86 −31.27 −30.70 S945 0.00 −2.36 −2.81 −7.24 −9.75 −11.23 −11.96 S961 0.00 −7.00 −12.92 −13.06 −18.69 −18.27 −23.91 CP943 0.00 −1.54 −7.97 −10.36 −17.23 −13.50 −12.60 S9510 0.00 −9.16 −12.05 −15.07 −20.16 −22.49 −26.07 Mean 0.00 −5.48 −9.93 −13.02 −17.43 −18.27 −19.83 SD 0.00 3.61 5.17 5.82 5.21 7.59 8.06 SEM 0.00 1.47 2.11 2.38 2.13 3.10 3.29
[0048] [0048] TABLE 4 PTH PTH PLASMA CONCENTRATIONS (pg/mL) AFTER ORAL ADMINISTRATION TO THE RHESUS MONKEY Dose: 1 Capsule 1B Animal Time [hours] no. 0 0.25 0.50 0.75 1 1.5 2 3 4 5 6 R944 0 83 191 300 360 262 154 35 0 0 0 S963 0 127 332 663 1258 150 34 0 0 0 0 Mean 0 105 262 482 809 206 94 17 0 0 0 SD 0 31 100 257 635 79 85 25 0 0 0 SEM 0 22 71 182 449 56 60 17 0 0 0
[0049] [0049] TABLE 5 PTH PTH PLASMA CONCENTRATIONS (pg/mL) AFTER ORAL ADMINISTRATION TO THE RHESUS MONKEY Dose: 1 Capsule 1D Animal Time [hours] no. 0 0.25 0.50 0.75 1 1.5 2 3 4 5 6 R927 0 0 0 0 0 0 0 0 0 0 0 S982 0 0 0 0 0 0 0 0 0 0 0 Mean 0 0 0 0 0 0 0 0 0 0 0 SD 0 0 0 0 0 0 0 0 0 0 0 SEM 0 0 0 0 0 0 0 0 0 0 0
[0050] As can be seen from the data in Tables 1-5, the sCT and PTH plasma levels are essentially the same whether the compounds are administered separately or together. However, the oral administration of a combination of PTH and calcitonin, while resulting in similar PTH and calcitonin plasma concentration levels as those attained upon administrations of each agent alone; quite surprisingly results in reduction of serum calcium concentrations to the level observed with calcitonin alone.
[0051] The foregoing embodiments and examples are given merely to illustrate the instant invention and are not intended to be limiting. Numerous other embodiments and variations are within the scope of the invention and readily accessible to those skilled in the art.
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A method for orally administering a parathyroid hormone, PTH, comprising orally co-administering to a patient in need of PTH an effective amount of a PTH and an effective amount of a calcitonin. The method according to the invention allows for the oral administration of PTH without the hypercalcemia, hypercalcuria and nephrolithiasis side effects.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/622,418, filed Oct. 27, 2004, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Suspended ceilings of various shapes and sizes are being increasingly used in order to add interest to various public spaces, such as retail outlets, contemporary office lobbies and halls, entertainment establishments, and the like. This has lead to the creation of suspended ceiling systems for defining spaces in which the ceiling panels lie in more than one plane, such as in vaults, transitions between different ceiling heights, islands, and waves.
One problem with such non-conventional ceiling systems is the difficulty of installing the suspending grid so that the runners for supporting the associated ceiling panels are maintained in accurate alignment. In particular, this difficulty has lead to increased time and cost for the assembly of such suspended ceiling systems.
Accordingly, by way of the invention described herein, a suspended ceiling system is provided that is particularly suited for providing a grid system that is curved in vertical plane, provides for accurate spacing and alignment of the grid elements, and facilitates quick assembly and installation of the assembled grid system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a grid system for a curved suspended ceiling in accordance with the present invention.
FIG. 2 is a perspective view of a portion of a primary carrier in accordance with the present invention.
FIG. 3 is a perspective view of a splice for connecting primary carriers in accordance with the present invention.
FIG. 4 is a perspective view showing the splice of FIG. 3 joining two primary carriers in accordance with present invention.
FIG. 5 is a perspective view of a portion of the grid system according to the present invention showing a clip for securing a primary carrier to a main runner.
FIG. 6 is an enlarged perspective view of the clip for securing the primary carrier to the main runner.
FIG. 7 is a perspective view of a portion of the grid assembly showing a connection of a primary carrier to a perimeter trim piece.
FIG. 8 is an enlarged perspective view of a clip for securing the primary carrier to the perimeter trim piece.
FIG. 9 is a perspective view of a portion of the grid system of the present invention showing the connection of a main runner to a trim piece.
FIG. 10 is an enlarged perspective view of a clip for securing a main runner to a trim piece.
FIG. 11 is a perspective view of a portion of the grid system showing two pieces of trim connected to each other by means of a splice clip.
FIG. 12 is an enlarged exploded perspective view of the splice clip for connecting two trim pieces together.
FIG. 13 is a perspective view of a hanger clip for securing the hanger wire to the primary carrier.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention comprises an assembly particularly suited for a curved suspended ceiling grid. With reference to FIG. 1 , the system, generally designated 10 , includes main runners or tees 12 which are curved in a vertical plane to support either flexible panels 13 or preformed, lay-in panels (not shown), the latter requiring cross-tees between adjacent main tees. The curve may be either concave or convex with respect to the exposed side of the ceiling system. Edge or perimeter trim pieces 14 (which may be either curved or straight, as required to correspond to the shape of the main runners 12 ), having opposed interior slots define the perimeter of the suspended ceiling. Corner clips are used to secure the perimeter trim pieces to each other. However, the perimeter trim may be omitted, if desired, without departing from the invention. Each of the main runners, trim pieces and corner clips have previously been available from Chicago Metallic Corporation, assignee of the present application, under the “CurvGrid” and “CurvTrim” trademarks.
In keeping with one aspect of the present invention, one or more primary or tube carriers, generally designated 20 , is utilized to interconnect the main runners 10 and provide a unitized, rigid grid system. Each primary carrier 20 preferably extends substantially the full width of the suspended ceiling and is preferably spaced no more than about 48 inches from the adjacent primary carrier. The primary carrier 20 may be of any length that is practical given both manufacturing and shipping constraints, and typically may be as long as 16 feet in length.
The primary carrier 20 preferably has a circular cross-section, with an outside diameter of approximately 1.25 inches, although other cross-sectional shapes and sizes may be utilized without departing from the invention. The primary carrier has a notch or slot 22 for each of the main runners supported by the tube carrier 20 , the notch 22 being sized in width and depth to receive the bulb of the main runner. In a preferred embodiment, the tube carrier 20 is roll-formed from 0.028 inch thick steel with a lock seam 20 a . The notches 22 aid in the installation of the ceiling by maintaining on-center spacing of the main runners 10 without the use of cross tees.
If the width of the curved ceiling is greater than the length of a single primary carrier 20 , adjacent primary carriers can be staggered so that together they extend substantially the full width of the ceiling. More preferably, one or more primary carriers may be joined together end-to-end to obtain the desired length by using a splice connector 21 , as shown in FIG. 3 . With reference to FIGS. 3 and 4 , approximately half the length of the splice connector 21 is received in the interior of each of the two primary carriers joined thereby. The primary carriers and splice connector may be positively secured to one another by fasteners, such as screws 21 a . The primary carriers 20 may also include an inwardly-projecting embossment spaced from their ends that serve as a stop to prevent over insertion of the splice clip 21 into the primary carriers 20 .
The splice connector 21 may be made from electrical metallic tube (commonly referred to as “EMT”) having an outside diameter and cross-sectional shape that is complementary to the inside diameter and cross-sectional shape of the primary carrier 20 . The splice connector 21 has a slot 21 b along its length to allow it to mate with a lock seam 20 a in the tube carrier 20 , thus preventing rotation of the splice clip 21 and maintaining the angular alignment of the splice clip relative to the primary carriers 20 .
With reference to FIGS. 5 and 6 , clips 24 with cut-outs 26 are provided that fit over the top of the primary carrier 20 to secure the main runners 10 to the primary carrier 20 . The cut-outs 26 are generally complementary in shape to the primary carrier and thus, in the illustrated embodiment, are generally an inverted U-shape. The clip 24 is provided with opposed faces 28 , the bottom edges 30 of which terminate in inwardly-pointing lips that are adapted to support the bottom surface of the bulb of the main runner. Alternatively, the clip 24 may be formed with inwardly-pointing tabs (not shown) for the same purpose. The clip 24 has aligned holes 34 in its opposed faces 28 for receiving screws 36 that draw together the lips or tabs on the clips so that they securely support the bulb of the main runner 10 . The clip 24 preferably includes stand offs 37 that are received on the shanks of the screws 36 and are sized in length to prevent over-tightening for the screws.
One advantage accruing to the present invention is that the primary carrier provides a cantilevered attachment point for the perimeter trim, allowing the hanger wire for suspending the grid to stand off from the end of the carrier tube, thus shielding the hanger wire from view. To this end, a perimeter clip 38 for securing the primary carrier 20 to a trim piece 14 is shown, best seen in FIGS. 7 and 8 . The primary carrier perimeter clip 38 comprises three L-shaped segments 40 , 42 , 44 , joined together on one leg of the L, that are bendable into a generally U-shaped member. When bent, the corner 46 of one leg of each of the outer L-shaped segments is partially received in the upper of two opposed slots on the trim pieces, while the edge 48 of the corresponding leg of the middle L-shaped segment is received in the lower of the two opposed slots. The other leg of each L-shaped segment extends generally perpendicularly from the trim piece 14 to support the primary carrier 20 . Each of the two outer arms that support the primary carrier 20 includes an aperture 50 adapted to receive a screw or other fastener for positively securing the clip 38 to the primary carrier 20 .
With reference to FIGS. 9 and 10 , a second perimeter clip 52 is shown for securing the main runners 10 to a perimeter trim piece. (Such clips may also be used to secure cross tees, if used, to a perimeter trim piece.) The main runner perimeter clip 52 is also generally L-shaped, with one leg of the L having opposed edges that are received in the opposed slots of the straight trim piece 14 . This leg preferably includes a tapped hole 54 for receiving a set screw 56 that may be tightened against the web of the trim piece 14 to lock the perimeter clip 52 thereto. Preferably, this leg has a curved edge 58 that permits the clip 52 to be positioned on the trim piece and then simply twisted to cause its edges to locate in the opposed slots in the trim piece. The other leg is adapted to lie along the web of the main runner 10 , and includes an ear 60 which can be folded through a slot in the main runner 12 to lock the main runner thereto.
Turning to FIGS. 11 and 12 , a splice clip 62 is provided for joining lengths of perimeter trim 14 to each other. The splice clip 62 has two parts 64 , 66 . The first part 64 has opposed edges 68 which are received in the opposed slots on the trim piece. The second piece 66 overlies the first piece 64 to clamp the lips that define the slots in the trim piece between the two pieces of the splice clip 62 . The second piece 66 has four corners 70 that are bent downwardly to engage the lips of the channels that receive the first piece 64 . The two pieces 64 , 66 of the splice clip 62 are attached together by a pair of screws 72 .
The grid system of the present invention is suspended by hanger wires secured to the primary carriers, rather than to the main runners. This minimizes the number of hanger wires required to support the system. For smaller-sized ceilings, the curved grid system as described can be easily and accurately assembled on the floor of the space in which it is to be installed, and then raised as a unit in order to secure the hanger wires to the tube carriers. Otherwise, the primary carriers 20 are first hung, and the remaining components of the grid system then secured thereto. With reference to FIGS. 1 , 4 and 13 , a plurality of hanger clips 74 is provided that secure the hanger wire to the primary carriers 20 . The hanger clips 74 have a strap portion 76 that is partially covered with a resilient, rubber-like sleeve 78 that conforms to the shape of the surface of the tube carrier 20 contacted by it. The hanger clips 74 have a slightly oversized opening with respect to the diameter of the primary carrier in order to permit a minor amount of relative rotation between the hanger clip and the primary carrier. This ability to rotate with respect to each other allows a certain amount of “self centering” of the tube carrier with respect to the hanger wire, so that the hanger wire extends generally perpendicularly from the primary carrier. This subjects the hanger wire to less stress at the point at which it is secured to the hanger clip.
Thus, a suspended ceiling system particularly suited for a curved grid has been provided that facilitates accurate and quick assembly with enhanced structural rigidity. While the invention has been described in terms of a preferred embodiment, it is not intended to be limited to the same. Indeed, variations are contemplated that are within the ordinary skill in the art. For example, while the system has been described in connection with curved main runners, the primary carriers could also be used with a more conventional planar grid system. In addition, while cross tees are not required for structural reasons, they may still be utilized with the present invention for aesthetic reasons if, e.g., the lay-in panels have an edge reveal. Also, the primary carrier may have a cross-section other than generally circular without departing from the invention.
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A grid system is provided that is particularly suited for the suspended ceiling system that varies in the vertical plane. An elongated carrier tube is provided the spans substantially the width of the grid system that has a slot therein adapted to receive the strengthening bulb of a main runner. A clip is provided that seats on the carrier tube that has opposed faces for capturing the bulb of the runner, so as to secure the runner to the tube carrier.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a phase locked loop oscillating circuit-called hereinafter a PLL circuit.
2. Description of the Prior Art
Usually, a conventional TV receiver uses a PLL circuit as a circuit to generate synchronous pulses with a frequency, which is synchronized, for example, with a horizontal synchronizing signal included in the complex video signal received and which is predetermined upon necessary correction for eventual variation to a certain degree in the frequency of this horizontal synchronizing signal. FIG. 1 shows a block diagram of a typical conventional PLL circuit 1, and the description below will be made by reference to this FIG. 1. This PLL circuit 1 is provided with a phase comparator circuit 2, into which, for example, a horizontal synchronizing signal H separated from the received complex video signal is fed. This phase comparator circuit 2 is equivalent to a three-state buffer 3, which is fed with sychronizing pulses SP1 obtained by dividing, with a divider 9, the synchronizing pulse SP given by a voltage-controlled oscillator (called hereinafter oscillator) 4 included in the PLL circuit 1 and which emits a phase difference signal PD as exhibited on the following truth table.
TABLE 1______________________________________Input Output______________________________________H SP PDH High impedanceL H HL L L______________________________________
The phase difference signal PD is fed to a mute adjusting circuit 5, which converts the signal into a phase difference signal PD1, as described later, and feeds it to an active low-pass filter (called hereinafter LPF) 6, where the high frequency components are removed and the filtered voltage DV is fed to the oscillator 4.
The mute adjusting circuit 5 has a resistor R1, a variable resistor VR, and a resistor R2 connected in series, wherein one end of the resistor R1 is grounded while the other end of the resistor R2 is connected with the reference voltage VO (for example 5 V). The LPF 6 includes a resistor R3 in series connection with the mute adjusting circuit 5 and an inverter circuit 7 connected in parallel with a series circuitry of resistor R4 and capacitor C1 and also with a capacitor C2. The inverter circuit 7 is formed as an integrated circuit in which the CMOS (complementary metal oxide semiconductor) technique is incorporated.
The time chart for the fundamental operating condition of the phase comparator circuit 2 is shown in FIGS. 8(1)-8(3) which will also be referred to in description of preferred embodiments. The phase difference signal PD in FIG. 8(3) is obtained by subjecting the level of the synchronizing pulse SP1 while synchronizing signal H in FIG. 8(1) is at Low level, to the level change indicated in Table 1. While the synchronizing signal H is at High level, the three-state buffer 3 shall be in high impedance condition, and the phase difference signal PD is set to the level of the bias voltage VB to be set by the mute adjusting circuit 5.
In case there is no phase difference between the synchronizing pulse SP1 and synchronizing signal H, that is in the condition that the synchronizing pulse SP1 will be switched over from Low to High level at the time t3 as TL/2 has passed from the time t1, where TL represents the Low level period from time t1 to time t2 of the synchronizing signal H as presented in FIG. 8(1), so the phase difference signal PD will be pulses with a duty cycle of 50% as shown in FIG. 2. The center value of the phase difference signal PD has the same level as the bias voltage VB (2.5 V) if the amplitude is selected to VO/2=2.5 V.
At this time, the PLL circuit 1 has the same duty cycle in its range below the bias voltage VB as the one above it, and thus the same frequency range can be used as the correctable range in both cases where the frequency of the synchronizing signal H varies from this condition to the high frequency side and to the low frequency side.
In case the input voltage Vin of the LPF 6 must be varied, the function to adjust the bias voltage VB of the phase difference signal PD1 is accomplished by the mute adjusting circuit 5. That is, the inverter circuit 7, used in the LPF 6, is realized as an integrated circuit according to the CMOS technique as described, and the threshold voltage which serves in determining whether the input voltage is at High or Low level, may vary element by element.
FIG. 3 is a graph exhibiting the input/output voltage relation of an LPF 6 having such an inverter circuit 7 as realized as an integrated circuit due to CMOS technique, wherein the line l1 corresponds to the case with proper threshold voltage while the line l2 corresponds to the case with improperly low threshold voltage, and the line l3 corresponds to the case with improperly high threshold voltage. When an integrated circuit element having such a proper threshold as presented by the line l1 is used as the inverter circuit 7 of the LPF 6, setting the center value of the phase difference signal PD1 to 2.5 V will cause emission of an output Vout=2.0 V in response to Vin=2.5 V in FIG. 3.
In case, by contrast, an integrated circuit element having a characteristic presented by the line l2 is used as the inverter circuit 7, acquisition of the same output voltage Vout=2.0 V involves adjustment for the input voltage Vin=2.0 V by the mute adjusting circuit 5. By this adjustment the phase difference signal PD becomes a signal obtained from the bias voltage VB turned into 2.0 V, shown by the broken line in FIG. 2. Accordingly the area SH of the portion above the new bias voltage VB=2.0 V will become larger than the area SL below the bias voltage VB, and in response thereto the output frequency of the oscillator 4 will vary to cause delay of the synchronizing pulse SP1 in the phase from the synchronizing signal H, as shown by the two-dotted chain line in FIG. 8(2). This gives the phase difference signal PD the same area S1 below the new bias voltage VB=2.0 V as the area SH above it, as indicated in FIG. 4, and the oscillator 4 will now output synchronizing pulses SP which are synchronous with the synchronizing signal H.
In the case that an integrated circuit element having a characteristic presented by the line l3 in FIG. 3 is used as the inverter circuit 7, acquisition of the same output voltage Vout=2.0 V involves adjustment for the input voltage Vin=3.0 V by the mute adjusting circuit 5. By this adjustment the phase difference signal PD becomes a signal obtained from the bias voltage VB turned into 3.0 V, shown by the two-dotted chain line in FIG. 2. Accordingly the area SL of the portion below the new bias voltage VB=3.0 V will become larger than the area SH above the bias voltage VB, and in response thereto the output frequency of the oscillator 4 will vary to cause advance of the synchronizing pulse SP1 in phase from the synchronizing signal H, as shown by the three-dotted chain line in FIG. 8(2). This gives the phase difference signal PD the same area SL below the new bias voltage VB=3.0 V as the area SH above it, as indicated in FIG. 4(2), and the oscillator 4 will now output synchronizing pulses SP which are synchronous with the synchronizing signal H.
The phase difference signal PD with a waveform as indicated in FIG. 4(1) is provided with a deviation that the duty cycles of the portions below and above the bias voltage VB are 60% and 40%, and the phase difference signal PD indicated in FIG. 4(2) is provided with a deviation that the duty cycles of the portions below and above the bias voltage VB are 40% and 60%, respectively, which allows the PLL circuit 1 to be set with different correction ranges for the case in which the synchronizing signal H shifts to a higher frequency side than the synchronizing pulse SP1 and the case of shifting to the lower frequency side. Use of this type of PLL circuit 1 in, for example, a TV receiver does not permit attainment of necessary correction range for varying frequency as specified, to result in generation of such a phenomenon as turbulence in the picture.
In case of further turbulence of the synchronizing signal H causes feeding of noise, pulse PD in FIG. 1 has added noise pulses 8 which are VO=5 or 0 V, as seen in FIG. 5, and the center value of the time average of the noise 8 will be 2.5 V. Use of an integrated circuit element having a proper threshold according to the line l1 in FIG. 3, at this time, for the inverter circuit 7 will give a bias voltage of 2.5 V to be set by the mute adjusting circuit 5, which is in good agreement with the center value of the noise. Use of an inverter circuit 7 having a threshold according to the line l2 in FIG. 3, on the contrary, allows the center value to be set to 2.0 V, as described above, after adjustment by the mute adjusting circuit 5. On the other hand, since the center value of the noise is 2.5 V, the center value as the time average of the whole waveform of phase difference signal PD become 2.25 V which is a median value of the center value of 2.0 V and 2.5 V mentioned above. Wherein in case the eliminated noise 8 causes feeding of the proper synchronizing signal H as shown in FIG. 9 to put the PLL circuit 1 into operation, a problem still remains that the center value will shift immediately from abovementioned 2.25 V to 2.0 V to cause oscillator 4 to output synchronizing pulses SP with different oscillating frequency between the state of noise 8 and the state of proper synchronizing signal.
SUMMARY OF THE INVENTION
A purpose of the present invention is to solve the described technical problems according to conventional arrangement and provide an improved phase locked loop oscillator circuit, whereby the range of mutual phase variation of a plurality of input signals is made uniform on both the high frequency and low frequency sides to allow emitting of oscillation signals having the same frequency.
Thus the invention applies to a phase locked loop oscillator circuit having structure that includes:
signal comparing means to compare a plurality of input signals with each other and emit a first control signal with a duty cycle corresponding to the degree of difference as a result from the comparison;
level converting means to supply a fixed level signal having a predetermined fixed level to the first control signal and emit the level of this resultant first control signal upon specified conversion;
signal converting means to emit a second control signal at a level corresponding to the duty cycle of the first control signal given by the level converting means; and
oscillating means to emit an oscillation signal at a frequency corresponding to the level of the second control signal and feed it to the signal comparing means.
Further this invention applies to a phase-locked loop oscillator circuit that includes:
signal comparing means to compare a plurality of input signals with each other and emit a first control signal with a duty cycle corresponding to the degree of difference as a result from the comparison;
level converting means, to convert the first control signal and emit the level of this resultant first control signal,;
first resistance means supplied with the first control signal to one side terminal and connected with a predetermined first constant level potential at the other terminal,
second resistance means supplied with the first control signal to one side terminal and connected with a second constant level potential different from the first constant level potential at the other terminal,
variable resistance means supplied respectively with each emission from the first resistance means and the second resistance means at both of its terminals, to produce an output of the difference in potential of each emission,
signal converting means to emit a second control signal at a level corresponding to the duty cycle of the first control signal given by the level converting means; and
oscillating means to emit an oscillation signal at a frequency corresponding to the level of the second control signal and feed it to the signal comparing means.
Another feature of the invention is that the signal comparing means is a phase comaprator circuit, which compares the phase of the synchronizing signal separated from the complex video signal and emits a first control signal with a duty cycle corresponding to the phase difference.
Further the invention is characterized by, that the level converting means is equipped with a variable resistor interposed between the predetermined reference potential and the ground potential, that the first control signal is fed to this variable resistor, and that it converts the level of the first control signal and emits the result of the conversion.
Also the invention is characterized by that the signal converting means is a low-pass filter equipped with a series circuitry consisting of an inverter circuit in CMOS (complementary metal oxide semiconductor) structure and a resistance.
In this phase locked loop oscillator circuit according to the present invention the signal comparing means is fed with a plurality of input signals including an oscillation signal from the oscillating means, compares the signals with each other, and emits a first control signal with a duty cycle corresponding to the degree of difference obtained as result of the comparison. This first control signal is supplied with a fixed level signal having a predetermined fixed level by the level converting means, and the level of this resultant first control signal is converted. A second control signal at a level corresponding to the duty cycle of the first control signal from the level converting means is emitted by the signal converting means, while an oscillation signal at a frequency corresponding to the level of second control signal is emitted by the oscillating means and fed to the signal comparing means.
Thus the level of the first control signal is converted after being supplied with a fixed level signal, so that its amplitude will also be converted. Even though the center level of the first control signal to be fed to the signal converting means must be shifted, the amplitude of the first control signal will be varied in response to the shift of the center level, which prevents occurrence of such a phenomenon that the duty cycle of the first control signal varies even after adjustment of the center value. This allows the input signal variation range, in which the frequency of the oscillation signal is held in locked condition, to be made uniform on both the high frequency and low frequency sides.
In this phase locked loop oscillator circuit according to present invention the signal comparing means is fed with a plurality of input signals including an oscillation signal from the oscillating means, the signals are compared with each other, and there is emitted a first control signal with a duty cycle corresponding to the degree of difference obtained as a result of the comparison. The first control signal is supplied to one terminal of the first resistance means in the level converting means, a predetermined first constant level potential is connected with the other terminal. The first control signal is supplied to one terminal of the second resistance means, and other terminal is connected with a second constant level potential different from the first constant level potential. Each emission from the first resistance means and second resistance means is supplied respectively to each terminal of the variable resistance means, which converts and outputs the level of difference in potential of each emission.
A second control signal at a level corresponding to the duty cycle of the first control signal from the level converting means is emitted by the signal converting means, while an oscillation signal at a frequency corresponding to the level of the second control signal is emitted by the oscillating means and fed to the signal comparing means.
Thus the level of the first control signal is converted after being supplied with a fixed level signal, so that its amplitude will also be converted. Even though the center level of the first control signal to be fed to the signal converting means must be shifted, the amplitude of the first control signal will be varied in response to the shift of the center level, which prevents occurrence of such a phenomenon that the duty cycle of the first control signal varies even after adjustment of the center value. This allows the input signal variation range, in which the frequency of the oscillation signal is held in locked condition, to be made uniform on both the high frequency and low frequency sides.
In the phase locked loop oscillator circuit according to the present invention, as described to this point, the first control signal from the signal comparing means is supplied with a fixed level signal having a predetermined fixed level from the level converting means, and the level of this resultant first control signal is converted. This is followed by the signal converting means emitting a second control signal at a level corresponding to the duty cycle of the first control signal given thus by the level converting means, and then the oscillating means outputs an oscillation signal with a frequency corresponding to the level of the second control signal.
As level conversion of the first control signal is made after being supplied with a fixed level signal, in this manner, its amplitude will also be converted, and even though the center level of the first control signal to be fed to the signal converting means must be shifted, the amplitude of the first control signal will be varied in response to the shift of the center level, which prevents occurrence of such a phenomenon that the duty cycle of first control signal varies even after adjustment of the center value, which allows the output signal variation range, where the frequency of the oscillation signal is held in locked condition, to be made uniform on both the high frequency and low frequency sides.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein:
FIG. 1 is a block diagram typically illustrating the configuration of a conventional PLL circuit 1;
FIG. 2 shows a waveform presenting the operation of PLL circuit 1.
FIG. 3 is a graph indicating the characteristics of the thresholds of the inverter circuit 25 in FIG. 7 and the inverter circuit 7 in FIG. 1.
FIGS. 4(1), 4(2), 5 and 6 show waveforms illustratively describing the operation of a conventional arrangement.
FIG. 7 is a block diagram presenting the configuration of a PLL circuit 11 as one preferred embodiment of the invention,
FIGS. 8(1), 8(2) and 8(3) are time charts exhibiting the operation of phase comparison circuit 12 in FIG. 7 and phase comparison circuit 2 in FIG. 1.
FIGS. 9, 10, 11 and 12 show waveforms describing the operation of the same embodiment of the invention.
FIG. 13 is a block diagram presenting the configuration of a PLL circuit 11a as another preferred embodiment of the invention, and
FIGS. 14 and 15 show waveforms presenting the operation of PLL circuit 11a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, preferred embodiments of the invention are described below.
Operation of the PLL circuit 11 as one embodiment of the invention will be described by reference to FIG. 7, which shows the configuration of the circuit in the form of a block diagram. This PLL circuit 11 is used, for example, in a TV receiver and generates a signal with an oscillation frequency synchronized with the horizontal synchronizing signal on the basis, for example, of the horizontal synchronizing signal separated from the complex video signal received.
The PLL circuit 11 is fed with a synchronizing signal H given from the outside such as the horizontal synchronizing signal of the video signal and with a synchronizing pulse SP1 obtained by dividing the synchronizing pulse SP, which is given by a voltage controlled oscillator (called hereinafter an oscillator) 26 included in the PLL circuit 11 by a divider 27 into a predetermined degree, and includes a phase comparator circuit 12 as a signal comparing means to generate a phase difference signal PD with a duty cycle corresponding to the amount of phase deviation upon comparison of the phases as described later. This phase comparator circuit 12 is equivalent to a three-state buffer 13, which operates in accordance with a table of truth value as shown in Table 1.
The output line 19 to which the phase difference signal PD is emitted, is connected with a level converting circuit 20 as a level converting means. This level converting circuit 20 consists of a resistor R6, a variable resistor VR1, and another resistor R7 in series connection, one end of the resistor R6 is grounded while the other end of the resistor R7 is connected with the reference potential VO (for example 5 V). The output line 19 is connected with a junction 21 between the resistor R7 and the variable resistor VR1.
A slider 22 included in this variable resistor VR1 is connected with the output line 23 of the level converting circuit 20, while this output line 23 is connected with an LPF 24 as a signal converting means. This LPF 24 is provided with a series circuitry of a resistor R8 and an inverter circuit 25, which can be formed as an integrated circuit due to CMOS technique, wherein the inverter circuit 25 is connected in parallel with a series circuitry of resistor R9 and capacitor C3 and with a capacitor C4.
The filtered voltage DV as the output from this LPF 24 is fed to the voltage controlled oscillator (called hereinafter an oscillator) 26, which emits a synchronizing pulse SP with a frequency corresponding to this difference voltage DV. This synchronizing pulse SP from the oscillator 26 is fed to the divider 27, as named before, to be divided with a predetermined frequency dividing ratio, and the resultant synchronizing pulse SP1 is fed to the three-state buffer 13.
Now a description is made by reference also to FIGS. 8 (1), 8(2) and 8(3) which illustrate a time chart for the fundamental operation of the PLL circuit 11. In the PLL circuit 11 built in a TV receiver etc., a synchronizing signal H as in FIG. 8(1) such as the horizontal synchronizing signal separated from the complex video signal received is fed to a phase comparator circuit 12, while the synchronizing pulse SP1 as in FIG. 8(2) obtained by dividing with the divider 27 the synchronizing pulse SP1 as the output of the oscillator 26 is fed to phase comparator circuit 12.
This phase comparator circuit 12 operates on the basis of the table of truth value in Table 1, which was described in the section of the Prior Art pertaining to the synchronizing signal H and synchronizing pulse SP1. Accordingly this phase comparator circuit 12 generates a phase difference signal PD with, for example, a minimum value of 0 V, a maximum value of VO (5 V), and therefore the center value DV as the mean value about the time being DV=VO/2 (=2.5 V), see FIG. 8(3). The period TD in FIGS. 8(1), 8(2) and 8(3) of the phase difference signal PD is in the variation range in which the duty cycle varies with respect to the phase difference between the synchronizing signal H and synchronizing pulse SP, while the period TS is in the fixation range in which the bias voltage VB set by the level converting circuit 20 is held.
Upon level conversion at the level converting circuit 20 as described later, this phase difference signal PD undergoes an integral operation outputting the difference voltage DV at a level corresponding to the duty cycle in the region SL below the center value CV, which is set by the LPF 24 about the phase difference signal PD in FIGS. 8(1), 8(2) and 8(3), with respect to the region SH above it. Thereby the oscillator 26 generates a synchronizing pulse SP with a frequency corresponding to the filtered voltage DV, and the sychronizing pulse SP1 as divided is fed back to the phase comparator circuit 12.
When a difference voltage DV of 2.0 V is endeavored to acquire in case the inverting circuit 25 has a proper threshold voltage on the line l1 in FIG. 3, the center value of the phase difference signal PD1 as output from the level converting circuit 20 must be set to 2.5 V. In the circuit shown in FIG. 7, the resistor value of R6 is set to 3 kΩ, the total resistor value of VR1 to 2 kΩ, and the resistor value of R7 to 5.1 kΩ, and then the slider 22 is connected with the junction 21. Therein the output line 19 is fixed to this junction 21 in FIG. 7, and therefore the phase difference signal PD will become a signal having an amplitude of 2.5 V, a center value of 2.5 V, and a bias voltage VB of 2.5 V, see FIG. 9.
Because the slider 22 is connected to the junction 21, on the other hand, the phase difference signal PD1 will become the same signal as the phase difference signal PD. In this condition, the area of the portion SL below the center value 2.5 V is identical to that of the portion SH above it, the duty cycle being 50%. Whether the synchronizing signal H is going to move from this condition to the high frequency side or low, the PLL circuit 11 will have the same correction range, in which oscillating motion can be made to generate a synchronizing pulse SP with the varying frequency according to moving of synchronizing signal H.
In case the inverting circuit 25 consists of a circuit with relatively low threshold as shown, for example, by the line l2 in FIG. 3, on the other hand, the center value CV of the phase difference signal PD1 must be set to 2.0 V. In the level converting circuit 20, therefore, the slider 22 is shifted from the junction 21 toward the ground potential. In case the slider 22 is connected with the junction 21, the VB=2.5 V has been accomplished by the added resistance value 5 kΩ of the resistance R6 and the total resistance value of VR1, so that the resistance value R for achieving CV=2.0 V is expressed as follows: ##EQU1##
Therefore, the amplitude of the phase difference signal PD in this embodiment is compressed by the ratio 5:4, which provides a phase difference signal PD1 as shown in FIG. 10.
With this phase difference signal PD1, the area of the portion SL below the new center value (CV) (2 V) remains equal to that of the region SH above it. This prevents occurrence of the phenomenon that the duty cycle of the phase difference signal PD is kept fixed to a value other than 50%, which was described by reference to FIGS. 2 and 4 in the section of the Prior Art.
Now description is made to the case where synchronization of the synchronizing signal H has become turbulent as shown in FIG. 11 to cause noise inclusion in the input, which has turned the phase difference signal PD into the condition of noise 28 in FIG. 11. In case the inverter circuit 25 consists of a circuit having the characteristic of the line l1 in FIG. 3, connecting the slider 22 with junction 21 gives a center value of 2.5 V, which is the time mean value of the phase difference signal PD, and this is identical to the bias voltage VB to be set by the level converting circuit 20. Use of an element having a constant threshold, as shown by the line l2 in FIG. 3, to the inverting circuit 25, on the other hand, will shift the slider 22 toward the ground potential in the level converting circuit 20.
At this time, the bias voltage VB in the level converting circuit 20 changes from 2.5 V to 2 V, but a compression takes place so that the level of the noise component 28 in the phase difference signal PD will also have a maximum value of 4 V. Accordingly, the time mean value of such noise components, i.e. the center value CV, will become 2 V, which is identical to the bias voltage VB. When noise input into the phase comparator circuit 12 is completed followed by input of the proper synchronizing signal H, therefore, undesired shift of the oscillation frequency as described associate with the Prior Art can be suppressed.
In description of the embodiment the cases with l1 and l2 in FIG. 3 were taken up in respect of the threshold of the inverting circuit 25, but the invention may be embodied even in the case of undesirably high threshold as shown by the line l3 in FIG. 3. Therein the variable resistor VR1 and resistor R7 in FIG. 7 may be put together to constitute one variable resistor, and the slider 22 be shifted from the junction 21 toward the power supply.
FIG. 13 is a block diagram of PLL circuit 11a as another embodiment of the invention. This embodiment has similar configuration of the embodiment mentioned above, corresponding parts are given equivalent reference symbols. Explanation of the corresponding parts is eliminated. The characteristic points of this embodiment are that the output line 19 to which the phase difference signal PD is emitted, is connected with a level converting circuit 20 as a level converting means. The level converting circuit 20 is provided with resistance R10, R11, R12, R13 in series, one terminal of a variable resistance VR1 is connected between resistance R10, R11 as the first resistance means, and another terminal is connected between resistors R12, R13 as the second resistance means, and the variable resistor VR1 is connected with resistors R11, R12 in parallel. An opposite terminal of resistor R13 against resistor R12 is connected with ground potential as the first constant level potential, and a opposite terminal of resistance R10 against the resistance R11 is connected with the reference potential VO (for example 5 V). The output line 19 is connected with a junction 21 between resistors R11, R12.
When a difference voltage DV of 2.0 V is endeavored to acquire in case the inverting circuit 25 has a proper threshold voltage on the line l1 in FIG. 3, the center value of the phase difference signal PD1 as output from the level converting circuit 13 must be set to 2.5 V. In the circuit shown in FIG. 13, the resistance value of R10-R13 is set to 1 kΩ, 10 kΩ, 10 kΩ, 1 kΩ, and VR1=1 kΩ and then the slider 22 is adjusted to the center of the variable resistance VR1. Therein the output line 19 is fixed to this junction 21 of fixed potential 2.5 V in FIG. 13, and therefore the phase difference signal PD will become a signal having an amplitude of 2.5 V, a center value of 2.5 V, and a bias voltage VB of 2.5 V, see FIG. 9.
By this operation, the amplitude of phase difference signal PD is surpressed identically in both parts above and below a bias voltage VB, thereby the phase difference signal PD1 can be generated. In this condition, the area of the portion SL below the center value 2.5 V is identical to that of the portion SH above it, the duty cycle being 50%. Whether the synchronizing signal H is going to move from this condition to the high frequency side or low, the PLL circuit 11 will have the same correction range, in which oscillating motion can be made to generate a synchronizing pulse SP with the varying frequency according to moving of synchronizing signal H.
In case the inverting circuit 25 consists of a circuit with relatively high threshold as shown, for example, by the line l3 in FIG. 3, on the other hand, the center value CV of the phase difference signal PD1 must be set to 3.0 V. In the level converting circuit 20, therefore, the slider 22 is connected with the position of the variable resistance VR1 emitting potential among minimum potential 1.7 V and maximum potential 3.3 V.
Therefore, the amplitude of the phase difference signal PD in this embodiment is compressed which provides a phase difference signal PD1 as shown in FIG. 14.
With this phase difference signal PD1, the area of the portion SL below the new center value (CV) (3 V) remains equal to that of the region SH above it. This prevents occurrence of the phenomenon that the duty of the phase difference signal PD is kept fixed to a value other than 50%, which was described by reference to FIGS. 2 and 4 in the section of the Prior Art.
Now description is made of the case where synchronization of the synchronizing signal H has become turbulent as shown in FIG. 11 to cause noise inclusion in the input, which has turned the phase difference signal PD into the condition of noise 28 in FIG. 11. In case the inverter circuit 25 consists of a circuit having the characteristic of the line l1 in FIG. 3, because the slider 22 is connected with the central position of the variable resistance VR1, the amplitude wave form of the phase difference signal PD is supressed identically in both parts above and below a bias voltage VB, to become the phase difference signal PD1, having a center value of 2.5 V, which is the time mean value of the phase difference signal PD1, and this is identical to the bias voltage VB to be set by the level converting circuit 20. Use of an element having a high threshold, as shown by the line l3 in FIG. 3, in the inverting circuit 25, on the other hand, will shift the slider 22 as mentioned in the level converting circuit 20.
At this time, the bias voltage VB in the level converting circuit 20 changes from 2.5 V to 3 V as shown FIG. 14, but a compression takes place so that the level of the noise component 28 in the phase difference signal PD will also have a maximum value of 4 V as shown in FIG. 15. Accordingly, the time mean value of such noise components, i.e. the center value CV, will become 3 V, which is identical to the bias voltage VB. When noise input into the phase comparator circuit 12 is completed followed by input of the proper synchronizing signal H, therefore, undesired shift of the oscillation frequency as described associate with the Prior Art can be suppressed.
In description of the embodiment the cases with l3 in FIG. 3 were taken up with respect to the threshold of the inverting circuit 25, but the invention may be embodied even in both the cases of suitable threshold and undesirably low threshold as shown by the lines l1 and l2 in FIG. 3.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.
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A phase looped oscillating circuit includes a signal comparing device which can compare a plurality of different input signals with each other and emit a signal based on this comparison. The signal comparing device emits a control signal to a level converting device, a signal converting device is operatively connected to the level converting device. A signal from the converting device is received by an oscillating device and an oscillating signal is fed back to the signal comparing device via a divider. To compensate for fluctuation of an invertor in the signal converting device, the signal comparing device provides a fixed level signal stabilized at a 50% duty cycle. This stabilization also stabilizes electrical noises that may be present.
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This application is a continuation-in-part of my earlier filed copending application bearing Ser. No. 765,918, entitled "Method and Apparatus For Installing an Off Shore Driving Rig" filed on Feb. 7, 1977, now U.S. Pat. No. 4,144,940.
BACKGROUND OF THE INVENTION
It is well known in the art that the supporting structure for pile driving hammers may be angularly positioned so as to drive pile on a slope or batter. Commonly, this is accomplished through the use of various apparatus for tilting the frame in which the hammer is supported. This frame frequently is supported by the boom of a crane such as in U.S. Pat. Nos. 3,734,435 and 3,888,317. Such cranes and their angularly disposed booms occupy substantial space and are not readily adapted to disposition on offshore platforms where space is limited; but the need for pile driving operations nevertheless is present. Frequently such pile driving operations are carried on offshore by disposing the crane and angulated boom on a derrick barge or the like. In such situation, there is no space occupied on the deck of the platform itself, but the derrick barge is very expensive to use. However, as disclosed in my earlier filed application, Ser. No. 765,918, there is shown a method for establishing a movable pile driving rig on the platform itself in order to drive pile and conductor pipe in a predetermined pattern and in the absence of a derrick barge or the like. In that case, it becomes imperative to occupy as little space as possible on the deck of the platform, while at the same time providing for angular adjustment of the lead over a broad range of angles.
Driving operations are commonly carried out from the upper deck of an offshore rig. The upper deck stands a substantial height above the water, as much as sixty feet or more. Therefore, the hammer can drive the pipe only to the level of the upper deck. The structural configuration of the rig further provides for a lower deck, frequently known as the cellar deck, this deck being commonly at a level or forty or more feet above the water. Also, there may be a jacket level proximate the surface of the water at perhaps ten or so feet above. Boat bumpers are frequently attached at the jacket level so that service vessels can tie up to the rig. Since the hammer can drive pile and pipe only to the upper deck, there frequently exists a residual length of pipe above the water after the pile or pipe has been driven to depth this being due to the fact that the hammer can only operate to the level of the upper deck. Therefore, the residual length of pipe must be cut off at some predetermined level in order to attach a Christmas tree or other production equipment. The cutting step is time consuming and, therefore, expensive.
THE INVENTION
Accordingly, the present invention provides for an advantageous structure in the form of a pile driving rig having an extensible knuckle lead therein capable of adjustment to from full batter to extreme angles of inclination which may be either positive or negative angles with respect to the vertical end without tilting the rig, that is the rig or boom supporting the lead.
Another advantage of the invention resides in a full hydraulically powered knuckle lead adjustment system, thus eliminating cables and their operational maintenance problems.
Another feature of the invention resides in the use of upper and lower kicker means.
Yet another feature and advantage of the invention resides in the use of new and improved kicker mechanisms both at the upper and lower end of the knuckle lead for selectively adjusting the knuckle lead within the pile driving rig either at the top or bottom thereof.
A further feature and advantage of the invention resides in provision for a knuckle lead support and adjustment system capable of angular inclination independently from either of two (2) points and within a vertically fixed tower or rig.
Still a further feature and advantage of the invention resides in a new and improved kicker mechanism providing for universal adjustment of the knuckle lead at both the top and bottom thereof.
A further feature and advantage of the invention resides in a provision for a knuckle lead which is adjustably positioned with respect to the water surface and can therefore move upwardly or downwardly through the upper deck of a rig.
A further feature and advantage of the invention resides in a knuckle lead which is movable upwardly or downwardly through the upper deck of a rig in order to drive a residual length of pipe or pile to depth.
A still further feature and advantage of the invention resides in a knuckle lead which is movable upwardly or downwardly through a hole in the upper deck of a rig in order to drive a residual length of pile or pipe to depth and to thus avoid the step of cutting such residual length.
A further feature and advantage of the invention resides in provision for a knuckle lead for carrying a pile driving hammer which is movable upwardly or downwardly through the upper deck of an offshore rig to the level of the lower deck or below thus minimizing joint cutting and welding and producing more economical hammering operations.
A still further feature and advantage of the invention resides in provision for a knuckle lead for carrying a pile driving hammer which is movable upwardly or downwardly from the lower deck, or even the jacket level of an offshore rig thus enabling the use of longer pipe and longer pile driving periods and minimizing welding time and resulting in more economical hammering operations.
These and numerous features and advantages of the invention will become more readily apparent upon a detailed reading of the following specification, claims and drawings, wherein like numerals denote like parts in the several views and wherein:
IN THE DRAWINGS
FIG. 1 is a side view of the pile driving rig showing the hammer and knuckle lead in a first operating position at a positive angle of batter.
FIG. 2 is a side view of the pile driving rig showing the hammer and knuckle lead in a second operating position at a negative angle of batter.
FIG. 3 is a top view of the upper kicker along the plan 3--3 of FIG. 1.
FIG. 4 is an end view of FIG. 3 along the plane 4--4 thereof.
FIG. 5 is a side view of FIG. 3.
FIG. 6 is a top view of the lower kicker along the plane 6--6 of FIG. 1.
FIG. 7 is a side view of FIG. 6.
FIG. 8 is an elevation view of an offshore platform having a pile driving rig thereon and showing the adjustable knuckle lead with the pile driving hammer operating at the level of the lower deck.
FIG. 9 is an elevation view of an offshore platform like that of FIG. 8 showing the pile driving rig operating at the level of the upper deck as is commonly done.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention here pertains to a system for selectively controlling, in economical manner, the angle of inclination of a pile hammer lead from an extensible to retractable batter positions. The pile driving rig in which the lead is supported is itself selectively movable over a pattern of skid track means 2 or the like, see FIG. 1, on the platform and as disclosed in the aforementioned Application. The rig consists of a structural tower arrangement consisting of vertical frame members 1 interconnected with diagonal braces 3, welded or otherwise structurally fastened to one another to form a derrick like rig which is supported on the aforementioned skid beams at the bottom and which terminates at the top thereof in the head plate 5. Structurally affixed to and supported by the head plate 5 is the upper kicker assembly 9 which includes the pulley arrangement for raising the knuckle lead, described hereinafter. Structurally affixed to and supported by the frame members 1 of the rig and at the lower end thereof proximate the skid beams is the lower kicker assembly 11. The lower kicker assembly and the upper kicker assembly 11, 9 respectively, though structurally affixed and supported by the rig, as previously explained, are characterized by an expansible-retractable means, such as a piston and cylinder arrangement, which is coupled to slide members that engage opposing tracks of the knuckle lead.
More specifically with reference to FIGS. 1 and 4, there is shown the upper kicker assembly 9 which comprises a parallel support beams 15 structurally affixed to the head plate at a predetermined distance from one another. Affixed to the end of each support beam 15 is a trunnion plate 17 having an alligned bore 19 in the upper end thereof. A yoke plate 21 is characterized by a plurality of integral reenforcing plates 21a and 21b each having bores alligned with the bore 19 in trunnion plate 17 so that upon insertion of the pins 23 there is provided a pivotal connection for yoke plate 21 with respect to trunnion plate 17. The yoke plate 21 is adapted to carry slide means 25 having a recess 25a which receives the flange 27 of knuckle lead 31. The trunnion plate 17 includes supporting plate 33 which is adapted to slide on the surface of support beams 15 upon actuation of the piston and cylinder means 37 which is affixed to its inner end to the head plate, and at the opposing end to the trunnion plate so as to thereby cause movement of the upper end 31a of knuckle 31 in the plane of movement of the piston.
Similarly, there is connected at the lower end 31b of the knuckle lead the lower kicker assembly means 11 comprising a second piston and cylinder means 45 which is structurally affixed to and carried by the frame of the pile driving rig. Slidably received within the cylinder is the piston portion characterized by a pivotal connection at the end thereof to a second slide means 57. The slide means 57 is, like the slide means 25, characterized by opposing recesses 55a adapted to receive the flange 27 of knuckle lead 31. Thus, upon actuation of the piston and cylinder means 45, the lower section 31b of the knuckle lead is caused to move toward or away from the cylinder in the plane of movement of the piston.
With reference to FIG. 8, there is shown the tower frame members 1 generally supported on tract means (not shown) which in turn rest upon the upper deck 101 of the rig 103. The rig further is characterized by a lower or cellar deck 105 and a jacket level 107 which commonly carries both bumpers and at which level service vessels tie up for loading and off-loading equipment and supplies from the rig 103. Supported within the frame members 1 is the aforedescribed knuckle lead 31 which is movable in accordance with the mechanics providing for the decrees of freedom as previously described. Operation of a conventional knuckle lead, as shown in FIG. 9, allows for hammering operations to take place above or at the level of upper deck 101 such that when pipe or pile joint 109 is driven to the level of deck 101 another joint like that of 109 must be hoisted to the level of the upper deck 101, carefully positioned with respect to the prior driven joint 109a, welded thereto, and driven by the hammer 67 to the level of upper deck 101, whereupon, the aforedescribed sequence is repeated. It may be visualized that the sequence of joints comprising 109, 109a, 109b (not shown) and so forth are driven to depth a residual length of joint will protrude above the surface 111 of the water. In order to then attach a Christmas tree or other production equipment to the pipe at the level of the lower deck where such production equipment commonly resides, the residual length of the pipe above the lower deck is necessarily cut off and removed. This step is necessary because the pile driving hammer 67 can operate only to the level of the upper deck 101.
As shown in FIG. 8, there is provided in the upper deck 101 a sufficient opening 113 through which the knuckle lead is able to move not only vertically but with some reasonable degree of lateral freedom. A diaphragm buffer may be provided in the opening. The opening is of sufficient size to allow passage of the knuckle lead and hammer therethrough. When the upper level of the joint has been driven to the level of the upper deck, hammering may continue by lowering the knuckle lead through opening 113 and by so doing the joint 109 may be driven down to or beneath the level of the lower deck 105. In fact, the end of joint 109 can be driven to any desired level above the surface 111 of the water and within the limits of the travel of knuckle lead 31. Thus, the surplus step of having to cut off the residual length of joint, after depth has been reached, due to the inability of the hammer to operate beneath the level of the upper deck, is avoided and substantial savings in time and money are achieved. Moreover, operation of the hammer at the level of the lower deck or below allows for utilization of longer length of pipe joint and hence savings in time taken for welding joints of pipe together and savings in time normally taken for cutting joints, all of which results in substantial improvement in the economics of hammering operations.
From the foregoing, it will be recognized that the pile driving rig of movable character as described in the afore-mentioned preceding Application, when characterized by the universally angulating knuckle lead disclosed herein, possesses market opportunity for the economic operations of driving a pattern of pile or conductor pipe in an offshore environment. By moving the pile driving rig on the skids to predetermined positions on the platform, the pile driving functions become readily accomplished without cumbersome movement of derrick barges. Likewise, the elimination of a drill rig for such preliminary operations becomes advantageous. Substitution of the pile driving rig therefor for the derrick barge and drill rig produces market savings because of the substantial costs otherwise incurred. Moreover, and further in accordance with the principles of this invention, the utilization of the universally angulating knuckle lead mounted within the pile driving rig and supported thereby for angularly positioning a diesel or other hammer means significantly increases the versatility of the already mobile and cost saving pile driving rig. The knuckle lead assembly, including the upper and lower kicker means 9, 11 enables movement of the lead at varying angles from the vertical both at the top and bottom thereof, thus substantially increasing the range of arcuate disposition from the vertical and enabling hammering operations to take place at extreme angles of inclination. Moreover, utilization of both the upper and lower kicker assembly within a vertically fixed structural tower or rig avoids the need for external draw works for tilting of the rig in order to achieve inclination of the knuckle lead 31. Furthermore, utilization of the upper kicker means 9 and lower kicker means 11 in conjunction with their respective slide means 25, 55, provides for the advantageous movement of the knuckle lead to elevated positions in order to vertically place pile sections or the like beneath the hammer preparatory to welding pipe sections and hammering. Thus, it will be visualized that the draw works 63, see FIG. 2 for example, can be operated to raise the knuckle lead to the substantial elevated position, this being in the range of up to the level of the lower kicker assembly 11, thus permitting concomitant raising of the hammer 67; see the elevated position of the knuckle lead in Ghost 65, (FIG. 2). Therefore, operation of the motor 67 drives winding drum 69 to either raise or lower knuckle lead 31 by reason of the sledded path of the draw works 63 around pulley 71 which is structurally attached to the knuckle lead. Elevation of the knuckle lead enables elevation of the hammer 67 to the position illustrated in Ghost in FIG. 2. Shifting of the motor 67 to operate winding drum 73 results in elevational movement of hammer 67 along the track of knuckle lead 31 by reason of the threaded path of hammer cable 77 about pulleys 79, 81 and 83.
An advantageous embodiment of the invention has been shown and described. It will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope thereof as set forth in the appended claims.
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An Angulating Knuckle Lead installed within an offshore pile driving rig having both upper and lower hydraulically actuated supporting kickers, independently operable for driving pile on extreme slope or batter and which is movable upwardly and downwardly through an opening in the upper deck of the rig toward the lower deck.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/826,585, filed May 23, 2013, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to methods and machines for cutting solid and semisolid materials, including food products.
[0003] The Affinity® dicer is a machine manufactured by Urschel Laboratories and is particularly well suited for dicing various materials, notable but nonlimiting examples of which include cheeses and meats. The Affinity® dicer is well known as capable of high capacity output and precision cuts. In addition, the Affinity® dicer has a sanitary design to deter bacterial growth.
[0004] A nonlimiting representation of an Affinity® dicer is shown in FIG. 1 . Product is delivered to a feed hopper (not shown) and enters a rotating impeller 10 , where centrifugal forces hold the product against an inner wall of a stationary case 12 equipped with a slicing knife 14 . The slicing knife 14 is disposed in an opening in the case 12 and typically oriented approximately parallel to the rotational axis of the impeller 10 . Paddles of the impeller 10 carry the product to the slicing knife 14 , producing slices that enter a dicing unit of the machine. Specifically, slices pass between a rotating feed drum 16 and feed roll 18 , then enter a rotating circular cutter 20 whose axis of rotation is approximately parallel to the rotational axes of the rotating feed drum 16 and feed roll 18 . The circular cutter 20 is equipped with circular knives oriented approximately perpendicular to the rotational axis of the circular cutter 20 and, therefore, such that the circular knives cut each slice into strips. The strips pass directly into a rotating cross-cutter 22 whose axis of rotation is approximately parallel to the rotational axis of the circular cutter 20 . The cross-cutter 22 is equipped with crosscut knives that are oriented approximately parallel to the rotational axes of the cross-cutter 22 , and therefore perpendicular to the circular knives of the circular cutter 20 , to produce final cross-cuts that yield a diced product. The rotational speed of the cross-cutter 22 is preferably independently controllable relative to the feed drum 16 , feed roll 18 and circular cutter 20 so that the size of the diced product can be selected and controlled.
[0005] FIG. 2 schematically represents a longitudinal cross-section of the cross-cutter 22 (not to scale) showing a hollow spindle 24 adapted to be coaxially mounted on a second spindle or shaft ( 38 in FIG. 3 ). The hollow spindle 24 defines a circumferential wall 26 in which slots 28 are formed for receiving cross-cut knives 30 of the cross-cutter 22 .
[0006] FIG. 3 is an exploded view showing individual components of the dicing unit of FIG. 1 , including the feed drum 16 , feed roll 18 , circular cutter 20 , and cross-cutter 22 and components associated therewith. As represented in FIG. 3 , each of the feed drum 16 , feed roll 18 , circular cutter 20 , and cross-cutter 22 is configured to be individually coaxially mounted on a separate shaft or spindle. In the nonlimiting representation of FIG. 3 , the feed drum 16 and cross-cutter 22 are shown as being individually mounted on separate spindle shafts 38 and secured thereto with a retaining washer 40 and nut 42 , and the feed roll 18 and circular cutter 20 are shown as being individually mounted on separate spindle shafts 44 and secured thereto with bolts 45 . FIG. 3 further represents a stripper or shear plate 32 supported and secured with bolts 36 to a support bar 34 . The shear plate 32 has an upper shear edge 47 adapted to strip products (strips) from the circular cutter 20 prior to being diced with the cross-cutter 22 . Slots 46 are defined in a surface of the shear plate 32 to accommodate the circular knives of the circular cutter 20 . The slots 46 extend to the shear edge 47 , such that individual edges of the shear edge 47 between adjacent slots 46 are able to remove strips from between adjacent circular knives. A lower shear edge 48 of the shear plate 32 is in close proximity to the knives 30 of the cross-cutter 22 to ensure complete dicing of the strips delivered from the circular cutter 20 to the cross-cutter 22 . The feed drum 16 , feed roll 18 , circular cutter 20 , cross-cutter 22 , shear plate 32 , and support bar 34 are all shown as being cantilevered from a support structure 50 of the machine, for example, an enclosure, frame and/or other structures interconnected with the stationary case 12 and including drive systems operable to rotate the impeller 10 , feed drum 16 , feed roll 18 , circular cutter 20 , and cross-cutter 22 at the desired rotational speeds thereof.
[0007] From the above, it should be apparent that the feed drum 16 , feed roll 18 , circular cutter 20 , cross-cutter 22 , stripper plate 32 , and support bar 34 must be securely and precisely positioned relative to each other, for example, to ensure that the circular cutter 20 , cross-cutter 22 and stripper plate 32 do not move relative to each other to the extent that the circular knives of the circular cutter 20 , the cross-cut knives 30 of the cross-cutter 22 , and the stripper plate 32 would interfere with each other. As discussed in reference to FIG. 3 , the feed drum 16 , feed roll 18 , circular cutter 20 , cross-cutter 22 , stripper plate 32 , and support bar 34 are all cantilevered from a side of a support structure 50 . The cantilevered design shown in FIGS. 1 and 3 promotes sanitation by making the components of the dicing unit readily accessible for cleaning. While completely adequate for many food processing applications, including cheeses for which the Affinity® is widely used, greater rigidity may be desirable when processing significantly harder food products, for example, frozen products.
BRIEF DESCRIPTION OF THE INVENTION
[0008] The present invention provides dicing machines and methods that promote the capability of producing diced solid and semisolid materials, particularly in the event that a relatively hard food product is being diced.
[0009] According to one aspect of the invention, a machine for cutting food products includes a stationary case surrounding a rotating impeller, a support structure interconnected with the stationary case, and a feed drum, a circular cutter, and a cross-cutter that are each individually rotatably mounted to the support structure by cantilevered shafts. The shafts of the feed drum, the circular cutter, and the cross-cutter each have an outboard end. The machine further includes a knife for producing slices by slicing a solid or semisolid material exiting through the stationary case under the influence of the impeller, circular knives on the circular cutter that are adapted and arranged to cut into strips the slices produced by the knife, and cross-cut knives on the cross-cutter that are adapted and arranged to dice the strips produced by the circular knives. The machine also includes a stripper plate having a first edge between the circular cutter and the cross-cutter for removing the strips from the circular cutter, and outboard support means for supporting and radially centering the outboard ends of the shafts of at least the feed drum, the circular cutter, and the cross-cutter and for supporting and securing the stripper plate relative thereto.
[0010] According to another aspect of the invention, a machine for cutting food products includes a stationary case surrounding a rotating impeller, a support structure interconnected with the stationary case, and a feed drum, a circular cutter, and a cross-cutter that are each individually rotatably mounted to the support structure by cantilevered shafts. The shafts of the feed drum, the circular cutter, and the cross-cutter each have an outboard end. The machine further includes a knife for producing slices by slicing a solid or semisolid material exiting through the stationary case under the influence of the impeller, circular knives on the circular cutter that are adapted and arranged to cut into strips the slices produced by the knife, and cross-cut knives on the cross-cutter that are adapted and arranged to dice the strips produced by the circular knives. The machine also includes a stripper plate having a first edge between the circular cutter and the cross-cutter for removing the strips from the circular cutter, and slots that extend to the first edge of the stripper plate wherein individual edges of the first edge between adjacent pairs of the slots remove the strips from between adjacent pairs of the circular knives. The stripper plate also has a second edge adapted to ensure complete dicing of the strips by the cross-cut knives of the cross-cutter, and means is provided for adjusting the placement and proximity of the second edge relative to the cross-cut knives. The machine also includes outboard support means for supporting and radially centering the outboard ends of the shafts of at least the feed drum, the circular cutter, and the cross-cutter and for supporting and securing the stripper plate relative thereto.
[0011] Other aspects of the invention include methods of using a machine comprising elements such as those described above. A particular but nonlimiting example is a method that entails installing the outboard support means on, and then subsequently removing the outboard support means from, a dicing machine as a complete unit and independently of the feed drum, the circular cutter, and the cross-cutter.
[0012] A technical effect of the invention is the ability to increase the rigidity of the circular cutter, cross-cutter and stripper plate to permit greater precision with respect to the placement and proximity of the second edge of the stripper plate relative to the cross-cut knives of the cross-cutter, which is desirable when processing relatively hard solid materials, for example, frozen food products.
[0013] Other aspects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 schematically represents an example of an Affinity® dicer machine.
[0015] FIG. 2 represents a fragmentary longitudinal cross-sectional view of a cross-cutter of the Affinity® dicer machine of FIG. 1 .
[0016] FIG. 3 represents a fragmentary exploded view of a dicing unit of the Affinity® dicer machine of FIG. 1 .
[0017] FIG. 4 represents a fragmentary perspective view of a dicing unit installed on a dicing machine, for example, the Affinity® dicer machine of FIG. 1 .
[0018] FIG. 5 is a fragmentary top view of the dicing unit of FIG. 4 , and shows a feed drum, circular cutter, and adjacent components in longitudinal cross-section.
[0019] FIG. 6 is a more detailed top view of outboard regions of the feed drum and circular cutter in FIG. 5 .
[0020] FIG. 7 is a further detailed top view of the outboard region of the feed drum of FIGS. 5 and 6 .
[0021] FIG. 8 contains a fragmentary perspective view of a stripper assembly of the dicing unit of FIG. 4 , and further contains an inset view of an adjustable feature of the stripper assembly.
[0022] FIG. 9 is an end view of the dicing unit of FIG. 4 , showing outboard ends of the feed drum, circular cutter, and stripper assembly as well as an outboard end of a cross-cutter of the dicing unit.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 4 through 9 depict a dicing unit installed on a dicing machine, for example, the Affinity® dicer represented in FIG. 1 . The dicing unit is adapted to produce cross-cuts in a sliced product to achieve a dicing effect and produce a diced product, though those skilled in the art will appreciate that the dicing unit and its benefits are not limited to such uses nor limited to the Affinity® dicer.
[0024] As represented in FIG. 4 , the dicing unit comprises components similar to that of the Affinity® dicer of FIGS. 1 through 3 . Furthermore, in the nonlimiting embodiment represented in FIGS. 4 through 9 , the dicing unit is configured to be adapted for use with the Affinity® dicer of FIGS. 1 through 3 , possibly as a retrofit for the Affinity® dicer, in that the dicing unit primarily comprises components that can be additional to or substituted for components shown in FIG. 1 through 3 . However, it should be appreciated that the dicing unit could also be provided as original equipment on a dicing machine. Because of the similarities between the dicing unit of FIGS. 4 through 9 and the dicing unit of FIGS. 1 through 3 , the following discussion of FIGS. 4 through 9 will focus primarily on aspects of the dicing unit of FIGS. 4 through 9 that differ from the dicing unit of FIGS. 1 through 3 in some notable or significant manner. Other aspects of the dicing unit of FIGS. 4 through 9 not discussed in any detail can be, in terms of structure, function, materials, etc., essentially as was described for the dicing unit of FIGS. 1 through 3 . Furthermore, consistent reference numbers are used throughout the figures to identify the same or functionally equivalent elements.
[0025] The dicing unit is depicted in FIG. 4 from a perspective view similar to that of FIG. 1 . In the nonlimiting embodiment of FIG. 4 , solid and semisolid materials, for example, food products, are delivered to an impeller (not shown, but corresponding to the impeller 10 of FIG. 1 ) through a hopper 51 mounted to the stationary case 12 surrounding and containing the impeller. According to one aspect of the invention, the dicing unit of FIGS. 4 through 9 differs from that shown in FIGS. 1 and 3 by including an outboard support means adapted to support the outboard ends of the otherwise cantilevered feed drum 16 , circular cutter 20 , cross-cutter 22 , stripper plate 32 , and support bar 34 attached to and projecting from one side of the support structure 50 . The nonlimiting embodiment of the outboard support means represented in FIGS. 4 through 9 comprises an outboard bearing assembly 52 that includes a plate 54 secured at one end to the stationary case 12 , and at an opposite end to the support bar 34 , with the feed drum 16 , circular cutter 20 , cross-cutter 22 , and stripper plate 32 located and rigidly supported therebetween. The plate 54 can be secured to the case 12 and support bar 34 with bolts 55 . While the plate 54 is represented as formed as a single unitary piece, it is foreseeable that the plate 54 could be an assembly of separate pieces. In some instances the case 12 and/or support bar 34 may require a modification to enable the plate 54 to be attached thereto, particularly if the outboard bearing assembly 52 is installed as a retrofit on an existing machine. Other locations and various means for securing the plate 54 to the machine are also within the scope of the invention. The outboard bearing assembly 52 is preferably configured as a removable unit to allow the machine and its dicing unit to be operated with or without the assembly 52 . In this manner, the machine can be operated without the assembly 52 when used to process products that do not require the additional rigidity provided by the assembly 52 , for example, semisolid food products such as cheese and certain solid food products such as meat. In addition, the assembly 52 represented in FIGS. 4 through 9 can preferably be removed as a complete unit so that the dicing unit and its components are readily accessible for cleaning.
[0026] The outboard bearing assembly 52 comprises means in the form of support subassemblies or units 56 , 58 and 60 for centering and rotatably supporting the outboard ends of at least the feed drum 16 , circular cutter 20 , and cross-cutter 22 . Particular but nonlimiting embodiments for the support units 56 and 58 for the feed drum 16 and circular cutter 20 are shown in more detail in FIGS. 5 , 6 and 7 . For use with a dicing unit of the type represented in FIG. 3 , the support unit 60 for the cross-cutter 22 may be similar to what is represented for the support unit 56 , and therefore is not shown in further detail. In FIGS. 5 , 6 and 7 , the support unit 56 for the outboard end of the feed drum 16 comprises a tapered cup 62 having internal (female) sloping walls that are complementary to external (male) sloping walls defined at an outboard end of the spindle shaft 38 of the feed drum 16 . In the embodiment shown in FIGS. 6 and 7 , the external sloping walls can be seen as defined by a fitting 64 secured to the end of the spindle shaft 38 , though it is foreseeable that the end of the spindle shaft 38 could be formed to have similar external sloping walls. The complementary tapers of the cup 62 and fitting 64 ensure centering of the spindle shaft 38 and accommodate radial tolerances. The cup 62 is supported by a bearing 66 that is secured to the plate 54 , for example, in a pocket 65 within the plate 54 and defined by and between the cup 62 and a retainer plate 67 , as most readily apparent from FIG. 7 . The pocket 65 is sized to allow axial movement of the bearing 66 , and a spring 68 within the pocket 65 axially biases the bearing 66 and cup 62 into engagement with the fitting 64 of the feed drum 16 to ensure axial tolerances are also accommodated.
[0027] FIGS. 5 and 6 depict a similar arrangement for the support unit 58 of the circular cutter 20 . The support unit 58 is represented as comprising a tapered cup 70 having internal (female) sloping walls that are complementary to external (male) sloping walls defined at the outboard end 72 of the spindle shaft 44 of the circular cutter 20 . Alternatively, it is foreseeable that a fitting similar to those of the spindle shafts 38 could be secured to the end of the spindle shaft 44 to define the external sloping walls. The complementary tapers of the cup 70 and outboard end 72 ensure centering of the spindle shaft 44 and accommodate radial tolerances. The cup 70 is supported by a bearing 74 that is secured to the plate 54 in a manner similar to the support unit 56 of the feed drum 16 , for example, in a pocket within the plate 54 and defined by and between the cup 70 and a retainer plate 75 to allow axial movement of the bearing 74 . A spring 76 axially biases the bearing 74 and cup 70 into engagement with the outboard end 72 of the spindle shaft 44 to ensure axial tolerances are also accommodated.
[0028] As previously noted, the outboard end of the support bar 34 is secured to the plate 54 of the outboard bearing assembly 52 , with the result that the rigidity of the support bar 34 and the stripper plate 32 are also increased relative to the machine represented in FIGS. 1 through 3 . This aspect of the invention is important in view of the function of the shear plate 32 , which requires accurate positioning relative to the circular cutter 20 and cross-cutter 22 in order to strip products (strips) from the circular cutter 20 and its circular knives 31 prior to the strips being diced by the cross-cut knives 30 of the cross-cutter 22 . As evident from FIGS. 5 and 6 , the slots 46 in the shear plate 32 individually accommodate the circular knives 31 of the circular cutter 20 , so that individual edges of the upper shear edge 47 between adjacent slots 46 remove strips from between adjacent circular knives 31 . Furthermore, as evident from FIG. 9 , the lower shear edge 48 of the shear plate 32 is in close proximity to the knives 30 of the cross-cutter 22 to ensure complete dicing of the strips received from the circular cutter 20 . The increased rigidity of the support bar 34 and stripper plate 32 permits greater precision with respect to the placement and proximity of the shear plate slots 46 and the individual edges of the upper shear edge 47 relative to the circular cutter knives 31 of the circular cutter 20 ( FIGS. 5 and 6 ) and the placement and proximity of the lower shear edge 48 relative to the cross-cut knives 30 of the cross-cutter 22 ( FIG. 9 ).
[0029] To enable adjustment of the distance between the shear edge 48 and cross-cut knives 30 , FIG. 8 represents a slot 78 (or other suitable form of recess) defined between the stripper plate 32 and support bar 34 , and a shim 80 received in the slot 78 and having a cross-section complementary to the slot 78 . The shim 80 may be one of any number of shims that are thicker than the depth of the slot 78 to cause the stripper plate 32 to tilt relative to the support bar 34 . As evident from FIG. 9 (which shows the plate 54 in phantom), increasingly thicker shims 80 result in increased tilting of the stripper plate 32 , causing the shear edge 48 of the stripper plate 32 to move toward the cross-cutter 22 , thus reducing the distance between the shear edge 48 and the knives 30 of the cross-cutter 22 . In the embodiment of FIG. 9 , shimming the stripper plate 32 about 0.001 inch (about 25 micrometers) can result in a movement of about 0.002 inch (about 50 micrometers) at the shear edge 48 of the stripper plate 32 . Without the additional rigidity of the dicing unit contributed by the plate 54 , the closer proximity of the shear edge 48 to the knives 30 could possibly result in interference therebetween, particularly if hard solid materials (e.g., frozen food products) are being diced.
[0030] From the above, it should be apparent that the feed drum 16 , feed roll 18 , circular cutter 20 , cross-cutter 22 , stripper plate 32 , and support bar 34 are securely and precisely positioned relative to each other with the outboard bearing assembly 52 , which is intended to ensure that the circular cutter 20 , cross-cutter 22 and stripper plate 32 do not move toward or away from each other during a dicing operation. The manner in which the spindle shafts 38 and 44 of the feed drum 16 , circular cutter 20 and cross-cutter 22 are supported by the support units 56 , 58 and 60 of the assembly 52 preferably does not alter the capability of independently controlling the rotational speed of the cross-cutter 22 relative to the feed drum 16 , feed roll 18 and circular cutter 20 so that the size of the diced product can be selected and controlled.
[0031] While the invention has been described in terms of a specific embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the physical configuration of the dicing unit and its components could differ from that shown, and various materials and processes could be used to manufacture the dicing unit and its components. Therefore, the scope of the invention is to be limited only by the following claims.
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Methods and machines for cutting solid and semisolid materials, including food products. The machine has a dicing unit that includes a feed drum, circular cutter, and cross-cutter each individually rotatably mounted to a support structure by cantilevered shafts. The machine further includes a knife for producing slices of a solid or semisolid material, circular knives on the circular cutter to cut the slices into strips, and cross-cut knives on the cross-cutter to dice the strips. The machine also includes a stripper plate for removing the strips from the circular cutter, and an outboard support assembly for supporting and radially centering outboard ends of the shafts of the feed drum, circular cutter, and cross-cutter and for supporting and securing the stripper plate relative thereto.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a charging device, e.g., for inductive charging of an energy store, a method for controlling a charging operation, and a corresponding computer program product.
2. Description of the Related Art
An accumulator which may be used, for example, to supply electrical energy to a small power device, is rechargeable with the aid of a corresponding charging unit. The accumulator and the charging unit may be connected to each other with the aid of electrical contacts, or a system of induction coils may be used to transmit electrical energy from the charging unit to the accumulator. The accumulator has a first energy coil which is configured to convert an external alternating magnetic field into a current which is used to recharge the accumulator following appropriate preparation. The charging unit has a corresponding second induction coil and is configured to generate the alternating electrical field, so that the two induction coils are coupled to each other in the manner of a transformer.
U.S. Pat. No. 6,803,744 B1 shows a charging unit which has a system of a plurality of second induction coils to facilitate an alignment of the accumulator with the first induction coil. In one specific embodiment, it is also shown that the induction coils may be moved relative to each other to achieve an improved magnetic coupling between the induction coils.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a charging device which provides a further improved magnetic coupling between the induction coils. Another object of the present invention is to provide a method and a computer program product for controlling a charging operation.
A charging device according to the present invention for a rechargeable energy store which has a first induction coil includes a coupling surface for positioning the first energy store, a second induction coil for generating a magnetic field in the area of the coupling surface to transfer electrical energy between the induction coils, and a direction control system for bringing an alignment of the field of the second induction coil in line with an alignment of the first induction coil.
It has been demonstrated that, to improve the magnetic coupling between the induction coils, it may be more effective to bring the alignment of the magnetic field in line with the alignment of the first induction coil than to move the induction coils relative to each other, in particular if the coupling surface is not much larger than the first induction coil.
In a first specific embodiment, the direction control system includes pivoting means for setting an elevation and rotating means for setting an azimuth in the second induction coil in relation to the coupling surface. A fast and accurate change in the alignment of the field of the second induction coil may be achieved with the aid of such a mechanical pivoting or rotation of the second induction coil.
In another specific embodiment, the direction control system includes multiple differently aligned subcoils, which are configured to generate magnetic subfields which are superimposed to form the magnetic field in the area of the coupling surface. In this way, the alignment of the magnetic field may be changed without requiring a mechanical movement of elements of the charging device. The superimposition of the magnetic subfields may result in the fact that the magnetic field is strengthened in the area of the first induction coil, whereby a transmittable amount of energy between the induction coils may be increased. By eliminating a mechanical tilting device, a distance between the induction coils or between the second induction coil and the surface may be reduced, whereby the magnetic coupling between the induction coils may be further improved.
In one specific embodiment, the charging device additionally includes a drive device for moving the second induction coil along the coupling surface in such a way that a position of the second induction coil is brought in line with a position of the first induction coil. The advantages of the alignment of the positions of the induction coils may thus be combined with the advantages of adjusting the alignments of the induction coils. Due to the combination, a mechanical complexity of the overall approach may be less than the sum of the complexities for the two individual approaches. This makes it possible to reduce the manufacturing and maintenance costs.
The charging device may include a control device for controlling the direction control system and/or the drive device, the control device being designed to permit the second induction coil to follow a movement of the first induction coil with regard to the coupling surface.
This makes it possible to support a charging operation in a harsh environment in which it is not possible to guarantee that the rechargeable energy store assumes a constant position or alignment in relation to the coupling surface. Conditions of this type may prevail, in particular, on board a motor vehicle, a ship or another means of transportation.
In one specific embodiment, the induction coils are configured to transmit energy in any direction. As an alternative to the inductive energy supply of the energy store, an inductive removal of energy from the energy store may also be made possible.
A method according to the present invention for controlling a charging operation of a rechargeable energy store having a first induction coil with the aid of the described charging device includes the steps of determining a first electrical power transmittable between the induction coils, changing the alignment of the magnetic field of the second induction coil in relation to the alignment of the first induction coil, determining a second electrical power transmittable between the induction coils, and changing the alignment of the magnetic field of the second induction coil on the basis of the comparison, for the purpose of maximizing the electrical power transmittable between the induction coils.
Due to the method, the alignment of the magnetic field of the second induction coil may be successively brought in line with the first induction coil, a rapidly converging optimization algorithm being able to be used, so that an optimum alignment may be quickly and reliably found.
In addition to the alignment of the magnetic field, a position of the second induction coil in relation to the first induction coil may also be changed. The alignment and the position may be changed successively or simultaneously in multiple runs of the method for the purpose of supporting the rapid convergence of the optimization algorithm.
A computer program product may include program code means for carrying out the described method, the computer program product being executed on a processing device or being stored on a computer-readable data carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a charging device having a rechargeable energy store.
FIG. 2 shows a direction control system for the charging device from FIG. 1 .
FIG. 3 shows another direction control system for the charging device from FIG. 1 .
FIG. 4 shows a flow chart for a method for controlling the charging device from FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a charging device 100 for charging a rechargeable energy store 105 . To facilitate referencing, a Cartesian coordinate system is specified. Charging device 100 includes a coupling surface 110 which is represented with an upward displacement in the manner of an exploded drawing.
Energy store 105 includes a first induction coil 115 , which is connected to an electrical storage device 125 with the aid of a control device 120 . First induction coil 115 preferably includes an electrical conductor which is wound multiple times in a circular shape. The first induction coil provides control device 120 with an electrical alternating current as a function of an alternating magnetic field 130 flowing through first induction coil 115 . Control device 120 converts the alternating current into a direct current and controls it in such a way that electrical storage device 125 may be recharged therefrom. Storage device 125 may be a capacitor, in particular a double layer capacitor, or an accumulator, in particular a nickel metal hydride or lithium ion accumulator.
Coupling surface 110 is represented as a flat rectangle, although coupling surface 110 may also have a different shape, in particular a curved shape in other specific embodiments. Coupling surface 110 is also not limited to being situated largely perpendicularly to the force of gravity.
Charging unit 100 includes a second induction coil 135 , which is mounted on a first carrier 140 which is movable in the y direction with respect to a first rail 145 . First rail 145 is mounted on a second carrier 150 , which is movable along a second rail 155 in the x direction. By correspondingly moving first carrier 140 and second carrier 150 , second induction coil 135 is fully movable on the x-y plane parallel to contact surface 110 . In another specific embodiment, second induction coil 135 may also be moved in a way other than with the aid of carriers 140 and 150 , for example with the aid of a moving device having a polar orientation.
Second induction coil 135 is mounted on first carrier 140 with the aid of one or multiple alignment elements 165 , alignment elements 165 permitting the second induction coil to pivot around the y axis and around the x axis.
The movements of alignment elements 165 of first carrier 140 and second carrier 150 may be controlled with the aid of a control device 160 , which is connected to the corresponding moving elements. Control device 160 is furthermore configured to control second induction coil 135 in such a way that it generates magnetic field 130 in the area of coupling surface 110 . The position and alignment of the magnetic field in relation to coupling surface 110 and, if necessary, also the strength of magnetic field 130 may thus be changed with the aid of control device 160 . Control device 160 is configured to move second induction coil 135 in such a way that the position and alignment of second induction coil 135 are optimized in the sense of an optimized magnetic coupling between first induction coil 115 and second induction coil 135 . For this purpose, induction coils 115 , 135 must be situated in such a way that they are located as close to each other as possible, while magnetic field 130 of second induction coil 135 flows perpendicularly through first induction coil 115 .
FIG. 2 shows a direction control system 200 for charging device 100 from FIG. 1 . Direction control system 200 represents an alternative means of attaching second induction coil 135 to first carrier 140 in the specific embodiment of charging device 100 illustrated in FIG. 1 . An additionally drawn coordinate system corresponds to the one in FIG. 1 .
Direction control system 200 includes a platform 205 for attachment to first carrier 140 . Platform 205 includes an upper section 210 and a lower section 215 , lower section 215 being configured for attachment to first carrier 140 , while upper section 210 supports second induction coil 135 . Upper section 210 is designed to be rotatable around the z axis in relation to lower section 215 , with the aid of a first drive device 220 .
Second induction coil 135 is attached to upper section 210 of platform 205 with the aid of a second drive device 225 in such a way that second induction coil 135 is pivotable around an axis which runs parallel to the x-y plane and corresponds to the x axis in the representation in FIG. 2 . If upper section 210 is rotated around the z axis in relation to lower section 215 of the platform, the axis around which second induction coil 135 is pivotable is also rotated. An azimuth (direction angle) may thus be changed with the aid of first drive device 220 , and an elevation (height angle) of second induction coil 135 may be changed with the aid of second drive device 225 . The alignment of second induction coil 135 in relation to the x-y plane is thus freely adjustable. The alignment of a magnetic field generated with the aid of second induction coil 135 also changes with the alignment of the second induction coil.
FIG. 3 shows another direction control system 300 for charging device 100 from FIG. 1 . As with charging device 200 from FIG. 2 , charging device 300 from FIG. 3 is configured to provide an alternative attachment of second induction coil 235 to first carrier 140 of charging device 100 from FIG. 1 and to simultaneously permit a change in the alignment of magnetic field 130 which may be generated by second induction coil 135 . A specified Cartesian coordinate system corresponds to the coordinate systems in FIGS. 1 and 2 .
Direction control system 300 includes a platform 305 similar to platform 205 , platform 305 , however, having a rigid design. Subcoils 310 through 320 , whose alignments differ from each other, are situated on the upper side of platform 305 . In the illustrated specific embodiment, the three subcoils 310 through 320 are inclined toward each other in such a way that axes, each of which runs perpendicularly through individual subcoils 310 through 320 , intersect above platform 305 at a point on the z axis. In other specific embodiments, subcoils 310 through 320 may also have other relative alignments or arrangements.
Each of subcoils 310 through 320 is configured to generate a magnetic subfield, the generated subfields being superimposed on each other to form magnetic field 130 in the area of coupling surface 110 , which is not illustrated, above platform 305 . Depending on the relative alignment of subcoils 310 through 320 and the relative strengths of the generated magnetic subfields, magnetic field 130 runs in a predetermined alignment in relation to the x-y plane in the area of coupling surface 110 .
FIG. 4 shows a flow chart of a method 400 for controlling charging device 110 from FIG. 1 .
A first electrical power, which is transmittable between induction coils 115 and 135 , is determined in a first step 405 . This may be done by control device 160 providing an alternating voltage to second induction coil 135 , which subsequently generates an alternating magnetic field 130 in the area of coupling surface 110 , so that alternating field 130 may be absorbed by first induction coil 115 and converted back into an electrical current. A current intensity resulting from second induction coil 165 provides an indication of the first transmittable power.
A changed alignment and/or a changed position of second induction coil 135 is/are determined in a subsequent step 410 . The determined alignment and/or position is/are implemented in a subsequent step 415 by controlling carriers 140 and 150 or drive devices 220 , 225 or subcoils 310 through 320 .
In a subsequent step 420 , a second transmittable power between induction coils 115 and 135 is determined similarly to step 405 . The first determined power is compared with the second determined power in a step 425 . If the first power is less than the second power by a predetermined amount, method 400 continues with a step 430 , otherwise it continues with a step 435 . The amount may be predetermined for the purpose of influencing a sensitivity of method 400 . The amount may be set to zero for a maximum sensitivity and thus a maximum optimization of the position of second induction coil 135 and the alignment of its magnetic field 130 in relation to first induction coil 115 in each case.
In step 430 , the first power determined in step 405 is set to the value of the second power determined in step 420 . This step is carried out if the changed alignment and/or position in steps 410 and 415 has/have produced an increase in the transmittable power. The method may subsequently continue with step 410 to bring about a further improvement in the transmittable power.
Step 435 is carried out if the change in the alignment and/or position in steps 410 and 415 have produced a decrease in the transmittable power. In this case, the changed alignment and/or position is/are reversed, and method 400 continues with step 410 for the purpose of increasing the transmittable power by another change in steps 415 and 420 .
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A charging device for a rechargeable energy store which has a first induction coil includes: a coupling surface for positioning the first energy store; a second induction coil for generating a magnetic field in the area of the coupling surface to transfer electrical energy between the first and second induction coils; and a direction control system for bringing an alignment of the field of the second induction coil in line with an alignment of the first induction coil.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to electroless deposition of metals. More particularly, it relates to the selective deposition of nickel on aluminum metallized semiconductor devices in predetermined areas defined by openings in a suitable dielectric or photoresist. Electroless deposition of gold is also described.
2. Description of the Prior Art
Aluminum is one of the preferred metals for semiconductor active device contacts for various reasons such as ease of evaporation, good electrical conductivity, and lack of adverse side effects on the electrical characteristics of the devices. However, the use of aluminum has two major problems: 1) it is not directly solderable and 2) it rapidly forms an impervious oxide. It is, thus, difficult to bond wire leads to the aluminum contact. One solution is direct thermocompression bonding of gold to aluminum. However, the composite degrades into a brittle intermetallic which degrades the contact. Another current technique is multimetallization as used for beam lead fabrication. This is a complex and costly procedure involving multiple photolithography steps to apply Ti/Pd/Au or Ti/Pt/Au metallization.
Nickel is an inexpensive, solderable material which can be used on top of aluminum metallization to enable contact of leads to the aluminum. Nickel also has the advantages of being harder than aluminum and more corrosion resistant. However, the formation of aluminum oxide has made it difficult to deposit nickel directly on aluminum without extensive pretreatment. A common pretreatment technique is zincating, the deposition of an intermediate zinc film which replaces the aluminum/aluminum oxide. Another example is ion activation, the activation of the surface with tin or palladium ions. Fluoride ions have also been used for activation but in large concentrations will etch into the aluminum. Ion activation and zincating overactivate and can cause deposition of nickel in areas other than where desired e.g., on a dielectric mask. The metals deposited during pretreatment also diffuse into the aluminum. Zinc diffusion, for example, reduces device lifetime by causing the aluminum to become brittle and, in the case of silicon, by altering the doping level.
SUMMARY OF THE INVENTION
The inventive method permits electroless deposition of nickel directly on aluminum or its alloys without the extensive pretreatment prevalent in the prior art and its consequent deleterious effects. The method is particularly useful for selective deposition of nickel in predetermined areas defined by apertures in a dielectric or photoresist. The pretreatment involves removal of aluminum oxide and activation of the surface with a subsequent step for deactivation of the mask relative to the aluminum. The electroless plating bath deposits nickel on the desired areas.
One aspect of this method is a pretreatment in which the substrate is immersed in a stop-etchant comprising buffered hydrofluoric acid and a nonaqueous solvent; and is then immersed in a solution of a soluble nickel salt. Another aspect is the subsequent immersion of the substrate in an electroless nickel hypophosphite-based plating bath which contains various stabilizers (e.g., formaldehyde), wetting agents (e.g., p-toluene sulfonic acid), buffers (e.g., sodium acetate), and buffered hydrofluoric acid to yield a good deposit and increase bath controllability.
This method has been used to apply thick nickel bonding pads on aluminized integrated circuits. The bonding pads hermetically seal the contact, thus, reducing environmental contamination of the device. The pad can be easily soldered to the lead wire or can be electrolessly plated with gold or copper for subsequent ball bonding or compliant applique bonding. Other applications include beam leading and plating of laser heat sinks and aluminum stud mounts. The method is economical for its simplicity and reliability. Bonding pads fabricated according to this invention have good mechanical strength and extended lifetimes.
Another aspect of the invention is an electroless gold plating technique which is suitable for depositing gold on the electroless nickel or other metals. The electroless gold plating bath is hypophosphite-based and is maintained at about neutrality by a suitable buffer (e.g., sodium bicarbonate).
The invention, as well as its advantages, will be better understood by reference to the following detailed description of illustrative embodiments read in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a flow diagram indicating the method steps for electroless deposition of nickel on aluminum.
FIG. 2 illustrates a nickel bonding pad as deposited on an aluminum metallized integrated circuit wafer by the method of FIG. 1. It further includes a gold layer deposited by the disclosed electroless gold plating technique.
FIG. 3 is a flow diagram indicating the method steps for beam leading an integrated circuit wafer with the inventive method.
FIGS. 4A-D are cross-sectional views of a beam leaded device at sequential stages during the processing described by FIG. 3.
DETAILED DESCRIPTION
General Technique
FIG. 1 shows the method steps in an illustrative embodiment of the electroless deposition of nickel on aluminum. The pretreatment encompasses two distinct steps which permit electroless deposition without deleterious side effects and confines deposition to the desired area if the substrate is masked. The first step in the pretreatment removes the aluminum oxide and simultaneously activates the entire surface. The second step activates the aluminum with nickel ions and, if patterned with a mask, deactivates the mask relative to the aluminum. A typical pretreatment for an aluminum metallized integrated circuit wafer having a silicon nitride mask is as follows:
______________________________________PRETREATMENT______________________________________STOP-ETCHANTBuffered hydrofluoric acid:ethylene glycol,:amyl acetate,:ethyl acetate,:ether,:ethyl cellusolve,Room Temperature, 18 C0.25-3 min (depending on concentration)Vol. ratio 1:2 to 4:1 -NICKEL IMMERSION Per liter H.sub.2 ONickel sulfate,chloride, 1.1-50 g 0.07-0.3MacetateAmmonium chloride,citrate, 3-40 g 0.05-0.75Macetatep-Toluene sulfonic acid 0.01-0.5 gBuffered hydrofluoric acid 0.01-10 mlRoom Temperature, 18 C15-60 sec______________________________________
Following standard cleaning procedures, the substrate is first immersed in a buffered hydrofluoric acid stop-etchant. Buffered hydrofluoric acid, BOE (Buffered Oxide Etchant), is a 6.7:1 (Vol.) mixture of 40% ammonium fluoride and 49% hydrofluoric acid. BOE when mixed with a nonaqueous solvent such as ethylene glycol, amyl acetate, ethyl acetate, ether, or ethyl cellusolve acts as a stop-etchant since it dissolves the oxide at a much faster rate than the aluminum. Fluoride ions activate the substrate surface. Variation of the ratio of BOE to solvent (preferably between 1:2 to 4:1) varies the etch rate and is modified to suit the aluminum surface composition.
Without rinsing, the wafer is transferred to the second step which is a nickel immersion treatment. Nickel ions exchange with fluoride ions on the aluminum surface and activate in a nondeleterious manner. The nickel complex is chosen by the amount of nickel ions one wants to produce. The chloride complex accelerates conversion to nickel ions while the acetate complex retards conversion relative to the sulfate complex. The other major component produces a common ion effect and provides an ion to exchange with fluoride ions on the mask surface. For example, chloride ions in ammonium chloride exchange with fluoride ions on the mask surface to deactivate it relative to the aluminum. This confines nickel deposition to the desired area. The citrate and acetate complexes deactivate more slowly than the ammonium chloride complex. p-Toluene sulfonic acid, p-TOS, wets the surface but is an optional component of the bath. A small amount of BOE is also included to prevent the formation of aluminum hydrous oxide.
Without rinsing, the wafer is transferred from the nickel immersion treatment to the electroless plating bath. At this point, there are fluoride and nickel ions on the surface which can readily be replaced with nickel metal. The deposition of the nickel metal is self-propagating. A typical bath composition with suitable concentration and reaction condition ranges is as follows:
______________________________________PLATING BATH per 1.5 liter H.sub.2 O______________________________________Nickel sulfate 15 - 45 g 0.05 - 0.2 MSodium acetate 5 - 65 g 0.04 - 0.5 MSodium hypophosphite 2.5 - 25 g 0.02 - 0.2MBOE trace - 10 ml.p-TOS trace - 0.15 gFormaldehyde trace - 50 mlEthanol trace - 150 ml.Boric acid trace - 65 g25 C - 95 Cslight agitationpH 3.5 - 7rate ˜ 0.1μm - 5μm/8 min.______________________________________
Concentration of the bath components is adjusted to accommodate various types of aluminum surfaces and to control deposit characteristics. Other reducible nickel salts, hypophosphites, or organic acid salt complexing agents may be used. The various buffers, stabilizers, and wetting agents affect deposit characteristics and bath controllability. The concentration of BOE requires control for quality deposits. A low molecular weight alcohol, such as methanol or ethanol, and p-TOS wet the substrate surface and reduce surface tension at the mask to aluminum interface. As an acid, p-TOS may also prevent formation of hydrous oxide on the substrate surface. Formaldehyde is a stabilizer. Boric acid stabilizes, buffers, and acts as a leveler to control particle size.
Time and temperature regulate the rate of deposit. Typically, one micrometer of nickel will be deposited in about 8 minutes at 72° C. To obtain thicker deposits, samples may be plated for longer time or the boric acid and BOE concentration can be reduced and/or sodium hypophosphite concentration can be increased. The nickel deposit contains 2-4% phosphorus which advantageously hardens the metal. Bath temperature can range from 25° C. to 95° C. with maximum efficiency at approximately 72° C. High temperatures cause the bath to decompose more quickly and low temperatures excessively slow the rate and may allow the acid in the bath to etch into the aluminum. The pH can range between about 3.5 and 7 with maximum efficiency at approximately 6.8. At pH 7, deposition is slow and particle size decreases. At pH 3.5, deposition is also slow and acid can attack the aluminum.
Subsequent to deposition, the substrate is rinsed with water, blotted to remove the excess, and allowed to air dry. It may be desirable to anneal the substrate in a reducing atmosphere such as forming gas (20% hydrogen and 80% nitrogen) at 200° C. to 425° C. Annealing assures bonding between aluminum and nickel.
In semiconductor processing, nickel pads may be directly soldered or with subsequent gold plating may be ball bonded, applique bonded, or subjected to other known procedures for providing leads or bonding to lead frames. As bonding pads, the thick nickel deposits spread laterally around the edges of the masked area and hermetically seal the contact area. This process also seals pinhole defects in the mask with nickel.
It may be desirable to plate the nickel deposit with gold or copper before further processing. A rinse with a mixture of BOE and ethylene glycol or some other nonaqueous solvent is recommended before electroless deposition of gold by the technique disclosed in Example II below or by a commercially available technique.
The following examples are given by way of illustration only and are not to be construed as limitations of the many variations possible within the scope of the invention.
EXAMPLE I
This example describes the formation of nickel bonding pads 20 on an aluminum metallized integrated circuit wafer to produce the structure illustrated in FIG. 2.
A silicon substrate 21 with a silicon dioxide passivating layer 22 was used. Aluminum layer 23 was thermally evaporated onto substrate 21. Apertures 26 were defined in silicon dioxide 22 to permit aluminum layer 23 to contact silicon substrate 21. A circuit pattern was defined on aluminum layer 23 by standard photolithographic techniques. Silicon nitride layer 24 was then deposited on aluminum layer 23. Standard photolithographic techniques were used to define apertures 27 in silicon nitride layer 24.
The wafer, having a top surface comprising silicon nitride layer 24 and aluminum layer 23, was processed according to FIG. 1. That is, the wafer was cleaned by rinsing in deionized water; scrubbing with Triton X 100 (trademark of Rohm and Haas); rinsing again in deionized water; and rinsing in ethylene glycol.
The wafer was then subjected to the following pretreatment:
______________________________________PRETREATMENT______________________________________STOP-ETCHANT(1:1) BOE:ethylene glycolRoom Temperature, 18 C75 secNICKEL IMMERSION Per liter H.sub.2 ONickel sulfate 66 gAmmonium chloride 0.18 g(10:1) H.sub.2 O:BOE 6 mlRoom temperature, 18 C35 sec______________________________________
The wafer was transferred to an electroless plating vat containing the following solution:
______________________________________PLATING BATH Per liter H.sub.2 O______________________________________Nickel sulfate 27 gSodium acetate 9 gSodium hypophosphite 4.5 gBoric acid 9 gp-TOS 0.09 g(10:1) H.sub.2 O:BOE 4.8 ml.Formaldehyde 0.6 ml.Methanol 6 ml.71.5CpH 6.860 min.slight agitation______________________________________
After removal from the plating bath, the wafer was rinsed with deionized water until the water resistivity returned to its original value. The wafer was air dried and the following properties were measured:
______________________________________Height of Nickel bondingpad 20 15.7μmResistivity 100-200 μohm-cmTensile Strength 1 × 10.sup.10 dyne/cm.sup.2Contact Resistance <0.01 ohmsDeposit Hardness 350 H.sub.v (Vicker Hardness)______________________________________
EXAMPLE II
This example discloses a technique for electroless deposition of a gold layer 25 on the nickel bonding pads 20 fabricated according to Example I and illustrated in FIG. 2.
Nickel pad 20 was scrubbed with Triton X 100 and rinsed in deionized water. The sample was rinsed with (1:1) BOE:EG and immediately transferred to the plating bath.
A plating bath comprising the following components was used to deposit gold layer 25 on nickel pad 20. Suitable concentration ranges are given.
______________________________________PLATING BATH Grams/Liter H.sub.2 O Moles/Liter______________________________________Potassium gold cyanide 0.5-10 0.0015-0.03Potassium cyanide 0.1-6 0.0015-0.09Sodium hypophosphite 1-20 0.009-0.19Sodium acetate 1-30 0.01-0.37Sodium bicarbonate 0.2-10 0.02-0.1218 C-98 CpH 45-9rate ˜ 0.1-0.5μm/15 min.______________________________________
The sample was rinsed with deionized water and after annealing the following properties were measured:
______________________________________Height of Ni-Au Deposit(layers 20 and 25) 15.2-15.5 μmResistivity 80-150 μohm-cmDeposit Hardness 180 H.sub.vAccelerated Aging <1% Pad Failure(85C, 85% relative humidity, 2000 hrs.)______________________________________
Wire ball bonds were fabricated by well known techniques using a thermocompression ball bonder. The strength of 1 mil gold wire was found to be between 10-15 g/wire.
The above-described technique for electroless deposition of gold is applicable to plating on most metals such as nickel, aluminum, copper, etc. The sample is pretreated with a mixture of BOE and a non-aqueous solvent to remove oxides on the surface. The bath components are illustrative. Other soluble gold cyanide complexes, cyanide salts, hypophosphites, etc. would be acceptable. The sodium acetate and sodium bicarbonate buffer the bath. For nickel, optimum results have been obtained at approximately pH 7. The technique is autocatalytic and, thus, produces thick deposits.
EXAMPLE III
This example illustrates a technique for forming beam leads by the inventive method. Beam leads are electroformed electrodes, frequently cantilevered beyond the wafer edges. FIG. 3 is a flow diagram of the process steps involved in creating the device shown in FIG. 4D.
A standard integrated circuit wafer as shown in FIG. 4A comprising silicon substrate 40, silicon dioxide passivating layer 41, and aluminum contact metallization 42 is the starting point. Aluminum metallization 42 is patterned with silicon nitride 43 to define contact areas. Another aluminum layer 44 is thermally evaporated onto the silicon nitride patterned aluminum. Photoresist 45 is applied to layer 44. Standard photolithographic techniques are used to mask the beam area as shown in FIG. 4B. The unmasked aluminum on layer 44 is etched away. Photoresist 45 is removed. FIG. 4C illustrate the resulting aluminum beam 46. Now, the electroless nickel deposition technique described in Example I is used to plate a thick nickel beam 47 over aluminum base 46. FIG. 4D illustrates the beam lead. The electroless gold deposition technique described in Example II is used to plate gold layer 48 on nickel beam 47.
It is to be understood that the above-described examples are merely illustrative of the many possible specific embodiments which can be devised to represent application of the principles of this invention. Numerous and varied arrangements can be devised with these principles by those skilled in the art without departing from the spirit and scope of the invention.
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A method for depositing electroless nickel on aluminum or aluminum alloy is described. The method is particularly useful for fabricating bonding pads on aluminum metallized semiconductor devices and for creating beam leads. The described method deposits a thick nickel layer directly on aluminum without the use of intermediate layers or surface activation as required in the prior art. The method basically comprises immersion in a stop-etchant which simultaneously removes aluminum oxide and activates the surface; immersion in a solution which activates the aluminum with nickel ions and deactivates mask material; and immersion in a novel electroless nickel bath. A technique for electrolessly depositing gold is also described.
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BACKGROUND
[0001] a) Field of the Invention
[0002] This invention relates to the field of safety devices for improving the visibility of a parked, stranded or disable vehicle, or other obstruction at day or night. The invention also relates to the field of demarcating or cording off a given area for safety or other reasons.
[0003] b) Description of the Related Art
[0004] The present invention is directed towards safety devices designed to improve the visibility of an obstruction on the side of a roadway and, more specifically, a disable vehicle in the breakdown lane of a roadway. One of the main problems encountered with obstructions or disable vehicles on the side of the roadway is visibility. Specifically, the ability of an oncoming motorists to sufficiently observe an obstruction or disable vehicle in sufficient time to determine the location of the obstruction or disable vehicle and take steps to avoid the same if necessary. There are a number of different methods to achieve the task of providing an early warning system to oncoming motorists that they are approaching a potential hazard in, or just off, the roadway. Among the methods are flares, reflective safety stickers that adhere to the side of the obstruction, reflective devices permanently attached to the obstruction, safety strips or belts, safety tape that is designed to rap around the obstruction, etc. However, none of these methods are as effective or efficient as the present invention in providing an early warning system to oncoming motorists.
[0005] Flares can be expensive, are only a single use device and when spread out on the roadway do not provide a continuous line of reflection as the present invention's reflective tape. Safety stickers or belts that attach or adhere to the disable vehicle, or obstruction, are small, difficult to see from a distance and as they are only attached directly to the vehicle do not provide an extra warning as the present invention does by being deployed several feet behind the vehicle. Safety devices that are permanently attached to the vehicle suffer from these same problems. In addition, these devices have the negative effect of being permanently attached to the vehicle thereby taking away some of the aesthetics of the exterior of the vehicle. On the contrary, the present invention is only used temporarily and thus is not a permanent fixture on the vehicle.
[0006] Reflective tapes that are designed to rap around the car suffered from the same above mentioned shortcomings as other devices that are designed to attach to the vehicle only. Also, these tapes are dangerous for the motorist to attach to the vehicle, as one needs to walk around the vehicle to apply the tape thereby requiring the motorist to walk into the travel lane on one side of the car and on the shoulder of the road on the other side of the vehicle. Consequently, the motorist runs the risk of being in the travel lane where there is oncoming traffic and the risk of walking on the unpaved shoulder of the road or highway which is not always the safest or level ground to walk on. The present invention overcomes the shortcomings of the prior art as it is designed to be temporary and deployed behind the vehicle or obstruction.
SUMMARY OF THE INVENTION
[0007] The present invention is a simple yet ingenuous design with few moving parts. The invention consists of mechanically connected reflective means with the preferred embodiment being a reflective tape. Alternative to tape, a lined device such as, but not limited to, a chain, cable, rope or other device that performs the same function could be used. The reflective tape is contained inside a housing. One end of the reflective tape is anchored inside of the housing while the other end of the reflective tape can be attached to a uniquely designed bracket that allows it to be connected to the obstruction or vehicle. Alternatively, the outer end of the reflective tape can contain a loop portion that may be used in conjunction with stands to demark a given area. When the invention is deployed in conjunction with a disable vehicle, or other obstruction, the reflective tape is first affixed to a vehicle, or other obstruction, and then it is deployed behind the vehicle. In the case of a disable vehicle in a breakdown lane of a roadway, the reflective tape is first attached to the vehicle and then is deployed behind the vehicle by the motorist walking away from the car while staying inside the safety of the breakdown lane. Once the reflective tape is fully deployed the housing is placed on the road surface and acts as an anchor to provide sufficient tightness to the reflective tape so that its movement is limited. Alternatively, the housing could be anchored to the car and reflective tape attached to a weighted device that is placed behind the car.
[0008] Once deployed the invention provides the benefit of being a continuous warning signal starting from a distance behind the disable vehicle to the vehicle itself. Consequently, oncoming motorist will have an early warning signal and also be able to track the signal (i.e. the reflective tape) directly to the disable vehicle ensuring that the motorist will be on notice of the direct location of the disable vehicle and be in a position to take steps to avoid the same. All of this is shown in FIG. 1 .
[0009] Therefore, the invention overcomes the shortcomings of safety devices that only attach to the vehicle itself. Also, as the reflective tape provides a single and continuous signal to the disable vehicle it overcomes the shortcoming of flares that are only dispersed individually along the roadway. In addition, the reflective tape allows the obstruction to be more visible rather than hidden behind the glare created by the flares. Lastly, the deployment of the invention provides the disable motorist with the safety of walking in the breakdown lane as opposed to the risk of entering the travel lane or the unpaved shoulder of the roadway.
[0010] If needed the invention can be used in conjunction with any other obstruction on the side of a roadway. Also, it can be used in conjunction with stands to act as a temporary barrier or a demarcation device to cord off a given area.
[0011] Accordingly, one object of this invention is to provide an inexpensive safety device that can be used in conjunction with disabled vehicles on the side of a roadway.
[0012] Another object of this invention is to provide a safety device that can be safety deployed by a disabled motorist.
[0013] A third object of this invention is to provide a device that can be used to safety mark off an obstruction on, or on the side, of a roadway.
[0014] A fourth object of this invention is to provide a safety device that can be easily stored and reused.
[0015] A fifth object of this invention is to provide a safety device that can also be used in other applications such as, but not limited to, a temporary barrier or a demarcation device to cord off a given area.
[0016] Other objects and advantages of this invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where,
[0018] FIG. 1 is a perspective view of the invention in its deployed position,
[0019] FIG. 2 is a perspective view of the invention,
[0020] FIG. 3 is a perspective view of the bracket,
[0021] FIG. 4 is a perspective view of the invention deployed with stands,
[0022] FIG. 5 is a perspective view of the stand connector,
[0023] FIG. 6 is a perspective view of the invention connected to a stand connecter,
[0024] FIG. 7 is a plan view of the invention,
[0025] FIG. 8 is a perspective view of the stand connector,
[0026] FIG. 9 is a cut away view of the interior of the housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to the Figures and more specifically FIG. 2 , the invention 10 consists of a generally cylindrical housing 12 , a deployment means, supporting retractable feet 18 and mechanically connected reflective means. The mechanically connected reflective means could be any line device such as, but not limited to a tape, chain, cable, rope or other device that performs the same function with the preferred embodiment being a reflective tape 16 . The deployment means could be by different methods such as, but not limited to, a hand crank, spring actuated deployment means similar in design to one used for electrical cords of vacuum cleaners or a spring actuate means used in common tape measures. The preferred embodiment of the deployment means is a hand crank 14 .
[0028] The housing 12 consists of a top portion 50 , a side portion 52 and a bottom portion 54 . The top portion 50 and bottom portion 54 are essentially flat planes that are parallel to each other. The side portion 52 is cylindrical in shape thereby giving the general overall shape of the housing 12 . The side portion 52 is also a means to connect the top portion 50 to the bottom portion 54 . An open slot 20 is disposed in the side portion 52 and is of sufficient size to provide a means to allow the reflective tape 16 to enter and exit the housing 12 . The open slot 20 should not be so large as to let dirt and debris into the housing 12 or onto the reflective tape 16 when the same is deployed in and out of the housing 12 . The open slot 20 is oriented in such a way that it runs perpendicular to both the top portion 50 and the bottom portion 54 . The open slot 20 also provides a means to keep the reflective tape 16 clean.
[0029] The hand crank 14 is disposed in the middle of top portion 50 and runs through the interior of the housing 12 parallel to the side portion 52 and is connected to the bottom portion 54 of the housing 12 (See FIG. 9 , internal view of housing). The hand crank 14 is connected to the housing 12 in a manner that is similar to a hand crank in a common tape measure. When the invention 10 is not in use the reflective tape 16 is disposed within the housing 12 . The hand crank 14 provides a means to retract the reflective tape 16 into the housing 12 . Alternative to the hand crank 14 a deployment means could be used to deploy the reflective tape 16 from the housing 12 and return the reflective tape 16 to the housing 12 . A number of different methods could be used to create the deployment means. A few examples, but not limited to, are a spring actuated deployment means similar in design to one used for electrical cords of vacuum cleaners or a spring actuate means used in common tape measures.
[0030] The feet 18 are connected to the bottom portion 54 of the housing 12 and provide a means to rest the invention 10 on a given surface when the invention 10 is in use. A number of feet 18 may be used with the preferred embodiment being three. The feet 18 have sharp points so that they may grip the surface that the invention 10 is placed on. When the invention 10 is not in use the feet 18 are designed to fold under the invention 10 for easy storage.
[0031] The reflective tape 16 has a plurality of different reflective colors with the preferred embodiment being two. The reflective tape 16 has a reflective portion 26 of one color and a reflective portion 44 of another color. As an example of one embodiment, the reflective tape 16 can be made out of any common material used for tape with the preferred embodiment being a flexible plastic or other cost effective material. The reflective tape 16 should however be made from material with sufficient strength to withstand the distance that it is deployed without breaking or sagging excessively during use (See FIG. 1 ). The reflective portions 26 and 44 can be made from any common reflective material with the preferred embodiment being cost effective and practical. The reflective material may be applied to the tape in any manner that is common to the tape industry. One end of the reflective tape 16 is connected to the portion of the hand crank 14 that is disposed within of the housing 12 in a manner similar to that of a common tape measure. The other end of the reflective tape, the exterior end loop 46 , is outside of the housing 12 and can be connected and/or anchored to any device necessary to use the invention 10 . When the invention 10 is used in conjunction with an obstruction on a roadway, the preferred embodiment of the invention 10 has the end loop 46 permanently fixed to the eyelet loop 62 of the bracket 22 (see FIG. 3 ). When the invention 10 is used in conjunction with free stands, the preferred embodiment of the invention 10 has the end loop 46 free allowing it to be placed over the peg 84 as seen in FIG. 8 . 0 .
[0032] FIG. 1 displays one example of the invention 10 in its deployed position when it is used in conjunction with day and night visibility marking a stationary obstruction close to the path of moving vehicle, in this case a disable vehicle on the side of a roadway. The disabled car 24 is parked in the breakdown lane 40 that is adjacent to the travel lane 42 . A line 56 that is generally white in color separates the travel lane 42 and the breakdown lane 40 . The travel lane 42 could be a major highway or an ordinary country road. In this application the invention 10 is deployed by first connecting the bracket 22 to the vehicle 24 (See FIG. 3 ), or other obstruction as the case may be, so that the invention 10 can give warning to travelers traveling in the travel lane 42 . The bracket 22 is immobilized once it is attached to the vehicle 24 . The reflective tape 16 is then deployed from the vehicle 24 a given distance by unwinding the tape from the housing 12 . Once the given distance is achieved the reflective tape 16 is pulled to a sufficient tightness, the feet 18 are deployed, and the invention 10 is rested on the road surface. The housing 12 is of sufficient weight such that its combination with bracket 22 being anchored to the vehicle 24 provides a means to maintain the tightness of the reflective tape 16 . Alternatively, the housing 12 can be attached to the bracket 22 and the end loop 46 is attached to a weighted device that is deployed behind the vehicle. If the housing 12 is used in this manner it need not be weighted. The combination of the housing 12 and the bracket 22 also provide a means to keep the reflective tape 16 elevated off the ground.
[0033] The reflective tape 16 is designed to deploy within the breakdown lane 40 . The reflective tape 16 it placed on the travel lane side of the vehicle 24 , or obstruction, and then deployed behind the vehicle 24 in the direction of the oncoming traffic. The housing 12 is placed on the ground in the breakdown lane 40 behind the vehicle 24 . The housing 12 is placed at a greater distance from the breakdown lane line 56 than the bracket 22 such that the reflective tape 16 is not parallel to the breakdown lane line 56 but creates an angle running across the breakdown lane. Once the reflective tape 16 is deployed as in FIG. 1 it can be seen from motorists driving in the travel lane 42 and approaching the disable vehicle 24 . At dusk or nighttime an oncoming car's headlights will illuminate the reflective tape 16 to act as an early warning that there is a broken down vehicle, or other obstruction, in the breakdown lane 40 . During the daytime the reflective tape 16 will act as an additional warning system with its highly visible characteristics.
[0034] FIG. 3 displays the bracket 22 and how it is attached to a car. The bracket 22 consists of main portion 58 , a collar 38 , an eyelet loop 28 and a connecting device 30 . The eyelet loop 28 consists of a stem 60 and a loop portion 62 . The loop portion 62 creates a loop opening 48 . The collar 38 provides a means to connect the eyelet loop 28 to the main portion 58 . The eyelet loop 28 provides a means of connecting the reflective tape 16 to the bracket 22 . The stem 60 of the eyelet loop 28 is disposed within the collar 38 and is affixed in a way so as to allow the eyelet loop 28 to spin freely within the collar 38 . The main portion 58 , the collar 38 and the loop eyelet 28 can be made of any sturdy material with the preferred embodiment being a metal or fiberglass material. The main portion 58 is bent at an angle with the preferred embodiment being a 90-degree bend. The main portion 58 is sufficiently long enough to allow the bracket 22 to be connected to the car while maintaining the reflective tape 16 a safe distance from the car to prevent the same from rubbing on the car. The connecting device 30 is affixed to the base of the main portion 58 .
[0035] The connecting device 30 is designed to secure the bracket 22 to the car. The connecting device 30 is designed to fit in the trunk, or rear opening, door jam of the car. The trunk door jam is that area that is created when one closes the trunk door 34 onto the rubber trunk gasket 36 of the trunk. The closing of the trunk door 34 onto the connecting device 30 and the rubber trunk gasket 36 secures the bracket 22 to the car. When the trunk door 34 is closed the connecting device 30 is dispose between the trunk door 34 and the rubber trunk gasket 36 . The connecting device 30 is made from a soft material so as not to damage the trunk door 34 or the trunk gasket 36 . The preferred embodiment is a pliable rubber material.
[0036] The connecting device 30 may also be used in conjunction with a van, caravan or pickup truck. In the case of a van or caravan the connective device 30 is placed in the jam created by the backdoor of the van or caravan. In the case of a pickup truck the connecting device can be placed in the jam created by the tailgate of the truck. Alternatively the bracket 22 may be secured to a disable vehicle, or other obstruction, using a number of attaching means. One such alternative attaching means, but not limited to this example, is the use of suctions cups 78 . The suction cups 78 may be attached to the rear window of the vehicle or any other adequate smooth surface on the vehicle. With the case of another obstruction the suction cups are simply attached to any flat surface of the obstruction.
[0037] The movement of the eyelet 28 in the collar 38 is necessary for a proper deployment of the reflective tape 16 . When the invention 10 is deployed it is generally level with the trunk lid 34 , as one would generally deploy the invention at one's waist level. Once the invention 10 is placed on the ground its level drops thereby causing the eyelet loop 28 to rotate clockwise. This rotational movement of the eyelet loop 28 maintains the reflective tape 16 in a flat orientation without it binding or folding. If necessary the eyelet loop 28 allows the invention 10 to be deployed in a 360-degree arc around the bracket.
[0038] Once the emergency is over the invention 10 can be returned to its storage position. One simply picks up to the housing 12 off the ground and winds the reflective tape 16 back into the housing 12 using the hand crank 14 . Once all the reflective tape 16 is disposed in the housing 12 one can remove the bracket 22 from the trunk door jam by simply opening the trunk door lid 34 and removing the bracket 22 from the door jam. The feet 18 are retracted under the housing 12 and the invention 10 is ready for storage.
[0039] An alternative use for the invention 10 is in a deployment to enclose an area for various reasons such as a construction site or a police barricade. In referring to FIG. 4 through FIG. 8 , the invention 10 is placed on stands that allow the reflective tape 16 to be elevated off the ground. There are two types of stands depending on the ground surface encountered. A self standing stand 64 can be used on a hard surface and has a weighted base 76 and pointed feet 18 . The weighted base 76 provides a means to keep the stand vertical. On the other hand a soft material stand 66 may be used when soft material is encountered. The soft material stand 66 is simply placed into the soft ground by applying pressure to the foot pegs 74 causing the spike 90 to go into the ground. The spike 90 provides a means to keep the stand vertical. As the invention 10 will be used in conjunction with the stands 64 and 66 the housing 12 does not have to be weighted and the feet 18 do not have to be present on the bottom of the housing 12 . Instead the feet 18 are place on the base 76 of the stand 64 . In the case of the self standing stand 64 no feet are necessary.
[0040] One will deploy the reflective tape 16 in the same manner as the car version but one will used the stands to hold the reflective tape 16 in position. Each stand has a tape connector 70 that accepts that exterior end loop 46 of the reflective tape 16 and provides a means to affix the reflective tape 16 to a given stand (see FIG. 5 and FIG. 6 ). The tape connector 70 consists of a plurality of pegs 80 with the preferred embodiment being four. The pegs 80 provide a means to secure both the reflective tape 16 and housing 12 to the tape connector 70 . In the preferred embodiment there is a return 84 that is in a 90-degree relation to the main portion of the two of the pegs 80 . The return 84 of a given peg 80 is in orientation with another peg 80 such that a gap 82 is created. All of the legs together create a cavity 86 designed to accept the reflective tape 16 and to secure the same to the stand. The width of the gap 82 is only slightly larger that the thickness of the reflective tape 16 thereby allowing the tape to be deployed within the cavity 86 but preventing the same from easily leaving the cavity 86 (see FIG. 5 ).
[0041] FIG. 6 through FIG. 8 show how the housing 12 and the end of the reflective tape 16 are attached to the stands. The housing 12 has two channels 88 attached to the side of the housing 52 . The inner diameter of the channel 88 is greater that the outer diameter of the peg 80 of the stand. The housing 12 is connected to the stand by placing it on the stand such that the pegs 80 , not containing the returns 84 , are disposed within the channels 88 (See FIG. 6 ). The channels 88 come to a rest at the base of the pegs 80 and the housing 12 is thus secured to the stand. The exterior end loop 46 of the reflective tape 16 is attached to the stand by simply placing it over the peg 80 that has the return 84 (See FIG. 8 ).
[0042] If more tape is needed one may utilize a second invention. This is done by attaching exterior end loop 46 of the second reflective tape 16 to the stand 66 , or 64 , where the previous housing 12 is affixed, and by sliding the end loop 46 the peg 80 that has the return 84 as shown in FIG. 8 . This allows a plurality of reflective tapes 16 to be chained together to mark off a large space.
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The present invention is an inexpensive safety tape that can be used in several applications including, but not limited to, the illumination of a disable vehicle on the side of a roadway. The invention consists of few moving parts including a housing, reflective tape and a connecting device that allows the tape to be connected to an object for demarcation. When used with a disable car on the side of a roadway the reflective tape is connected to the vehicle and then deployed behind the vehicle in such a manner that it provides an early warning system to oncoming traffic. Alternatively, the invention can be used with a stand that allows the reflective tape to be used as a temporary barrier or a demarcation device to cord off a given area.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and apparatus for cleaning fluid used in an industrial operation, such as a water purification plant, a completion or workover operation of a subterranean well, or the like, wherein a disposable cartridge filter is used to clean the fluid without production of a substantially non-porous solids filter cake around the exterior of the cartridge filter, and to a method of cleaning the cartridge filter utilizing the cleaned fluid in the cleaning procedure.
2. Brief Description of the Prior Art
Disposable cartridge filters are well known to those skilled in the art of cleaning fluids used in industrial operations, such as in municipal waste and water purification operations, refinery and chemical manufacturing operations, food processing procedures, and in the completion and/or workover operations of subterranean oil and/or gas wells. Such disposable cartridge filters generally are formed of a paper-like substance and are designed to be received within a vessel housing same and are removed, disposed of, and replaced with new filters as needed.
In industrial operations wherein a fluid, such as water or the like, is to be cleaned of particulate contaminate matter, such as fine sand, silt, and other similar solids, which is deemed to be a contaminate for one reason or another, a plurality of the cartridge filters will be placed within the vessel and the fluid flow containing the contaminate matter is introduced into the vessel for filtering of the particulate matter around the exterior of the filter, such that the clean fluid passes interiorly through the cartridge filter thence outwardly of the vessel.
When fluids associated with such industrial operations are cleaned incorporating such cartridge filters, a filter cake formed of said particulate matter can be expected to accumulate around the exterior surface of the cartridge filter, and in some events, into the filter media itself, reducing the effectiveness of the cleaning operation and the rate of flow of fluid therethrough and otherwise adversely affecting the filtering operation. As a result of the formation of such filter cake, such cartridge filters must be cleaned or replaced from time to time. Such cleaning or replacement is often time consuming and otherwise costly, resulting in considerable downtime for the flow of fluid during the industrial operation.
In the past, those skilled in the art have attempted to extend the useful life of such disposable cartridge filters by, for example, controlling the pressure of the flow through the filtering system to eliminate or greatly reduce any differential pressure across the cartridge filter exterior face to avoid a buildup of such a non-porous filter cake. Typical of such procedures is that disclosed in U.S. Pat. No. 1,780,723, entitled "Control for Oil Filters", and U.S. Pat. No. 3,926,806, entitled "No-Bypass Filter System".
The present invention provides a method and apparatus for removing particulate matter from fluids circulatable into, through and out of an industrial operation, as well as to a method and apparatus for cleaning of disposable cartridge filters by maintaining a specific minimum flow rate range per filter surface area per minute, as opposed to reducing or eliminating differential pressure across said cartridge filter to provide a substantially non-porous solids filter cake around the exterior of the cartridge filter.
The commonly accepted optimal flow rate through a disposable cartridge filter has thought to be about one-half gallon per square foot per minute, or 1.8925 liters per 144 square inches, or 1,892.5 ml per 144 square inches, which is equal to 13.14 ml per square inch surface area of filter per minute. In contrast, in the present invention, the flow rate across the disposable cartridge filter is maintained at an optimal flow rate. While such flow rate is, of course, dependent upon the construction and other parameters of the selected disposable cartridge filter, the vessel incorporating such filter, and the chemical composition of the fluid to be cleaned therethrough, as well as the volume, particle size and composition of the contaminate particulate matter, typically, such critical flow rate range will be from between about 0.19 ml per square inch of cartridge filter surface per minute to about 1.73 ml per square inch of disposable cartridge filter surface per minute. Preferably, it has been found that such optimal flow rate will be about 0.575 ml per square inch of cartridge filter surface per minute.
By controlling the flow rate through the filter means, particles forming the particulate matter are not effectively carried with the fluid stream and tend to settle out and not be deposited around the exterior of the cartridge filter to thereby be available for the formation of any adverse cake thereacross. Accordingly, any filter cake that develops on the filter media of the disposable cartridge filter is not compressed and does not develop any significant thickness because the force of gravity acting on such cake will be greater than the fluid flow force holding the cake in place. Accordingly, any filter cake that develops will be porous and will retain its permeability and allow the fluid flow rate to be maintained by increasing pump pressure in incremental stages.
In the past, those skilled in the art of incorporating disposable cartridge filters into cleaning operations for industrial applications have encountered considerable problems in cleaning of such cartridge filters upon the occurrence of a buildup of an adverse cake. When such cartridge filters are cleaned by reversing flow of fluid through such filters, the resultant produced dirty fluid must be disposed of in some environmentally acceptable manner. The present invention addresses such problem by providing a system for cleaning of such cartridge filters, in place, incorporating the cleaned fluid produced through normal filtering operation and providing a back flush procedure which does not produce a resultant fluid flow which might be difficult to dispose of because of environmental safeguards.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus of cleaning a disposable cartridge filter while in a vessel incorporated into a filtering system used to remove contaminate particulate matter from fluids circulatable into, through and out of an industrial operation. The method includes the steps of providing a filtering system comprising a first vessel housing at least one disposable cartridge filter and a storage vessel in selective fluid communication with the interior of the first vessel for receipt of filtered clean fluid. A purge vessel may also be provided in one form of the invention and is in selective fluid communication with the clean fluid storage vessel and the first vessel for receipt of fluid and particulate matter during the cleaning. The clean fluid is flowed from the storage vessel into the interior of the cartridge filter thence through and out of the exterior of the cartridge filter to effectively remove any particulate matter deposited on and around the exterior of the cartridge filter.
In one form of the invention, the cartridge filter is first hydraulically cleaned by such a procedure and thereafter is followed by pneumatic cleaning, which may be in the form of a throttling or vibratory action, to completely remove any particulate matter in cake or noncake form from around the exterior of the cartridge filter.
The present invention also provides a method for removing contaminate particulate matter from fluid circulatable into, through and out of an industrial operation by forming a fluid flow path into, through and out of the industrial operation and thereafter circulating fluid in the flow path. The circulated fluid is introduced into a filtering vessel to remove the contaminate particulate matter from the fluid to thereby provide a clean fluid with the vessel comprising at least one disposable cartridge filter. The circulated fluid is flowed through the cartridge filter at a rate of flow insufficient to produce a buildup of a substantially non-porous solids filter cake around the exterior of the cartridge filter.
The rate of flow should be no more than about 1.73 ml per square inch of cartridge filter surface per minute. Generally speaking, the rate of flow should be from between about 0.19 ml per square inch of cartridge filter surface per minute and about 1.73 ml per cartridge surface inch per minute.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic illustration of the method and apparatus of the present invention wherein a first or filtering vessel is being filled with a dirty fluid.
FIG. 2 is similar to that of FIG. 1 in which dirty fluid is being filtered and passed to the storage vessel.
FIG. 3 is a view similar to that of the previous views showing normal flow operation during fluid circulation for the industrial operation.
FIG. 4 is a view similar to that of the previous views showing back washing of the filtering apparatus.
FIG. 5 is a view similar to the previous views showing the cleaning operation for the cartridge filter apparatus to filter fluid from the purge tank for cleaning and depositing within the storage vessel.
FIG. 6 is a view similar to the previous Figs. illustrating removal of clean fluid from the storage vessel into the purge vessel after the cleaning sequence.
FIG. 7 is a view similar to the previous views showing refiltering of fluid within the purge vessel.
FIG. 8 is a view of the sequence of operations subsequent to the procedure set forth in FIG. 7, and is identical to the procedure set forth in FIG. 3.
FIG. 9 is a view similar to that of the previous views showing removal of contaminate particulate matter within the second chamber of the first vessel through the auxiliary filter means to provide clean fluid therefrom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now with reference to FIG. 1, there is shown a filtering system 100 which generally comprises a first vessel 101 and a separate storage vessel 117 above a purge tank 129 in selective communication therewith. Of course, the storage vessel 117 and purge tank 129 may be provided as separate components, it being necessary only that the tank 129 and vessel 117 be in selective fluid communication between one another, and that the vessel 117 be in selective communication with the first vessel 101.
The first vessel 101 defines first and second fluid chambers, 102, 103 which are always in fluid communication, with a baffle 104 having ports 104a positioned approximately medial of said chambers, 102, 103. The ports 104a defined through the baffle 104 provide continuous fluid communication between the chambers, 102, 103, with the solid surface of the baffle 104 receiving a clean fluid line 112 extending through the first vessel 101 and communicating to the interior of one or more disposable cartridge filters 105 housed within the first chamber 102 on the baffle 104.
A dirty fluid inlet 110 communicates with the industrial operation and contains valve 111 of known construction which is selectively movable between open and closed positions with the line 110 being extended through the outer housing of the first vessel 101.
At the top of the first vessel 101 is a purge line 106 communicating between the first chamber 102 and the purge tank 129 with valve 107 placed thereon for controlling fluid flow selectively through the line 106.
An air vent 114 is also provided at the top of the first chamber 102 of the first vessel 101 with a similarly controlled valve 114A thereon to control venting of air, as described below.
The second chamber 103 of the first vessel 101 preferably houses an auxiliary filter means 109, which as shown, is also a disposable cartridge filter of the same construction of the disposable cartridge filters 105 positioned on the baffle 104 and housed within the first chamber 102.
At the lowermost end of the second chamber 103 is a drain line 115 and drain line valve 116 to permit draining of the fluid within the second chamber 103, as described below.
The lowermost end of the disposable cartridge filters 105 is in communication with the fluid flow line 112 having valve 113 thereon with the line 112 extending through the outer housing of the storage vessel 117 to a seal or diaphragm chamber 123 separating the storage vessel 117 from the purge tank 129. A valve 122 is placed on the exterior of the vessel 117 immediate the purge vessel 129 and is manipulatable to permit or prevent fluid communication between the vessels, 117, 129.
The storage vessel 117 will receive clean fluid which is filtered through the disposable cartridge filter 105 and communicated through the clean fluid line 112 thereto. An air vent line 120 is positioned through the top of the storage vessel 117 with valve 121 thereon manipulatable between closed and open positions to control the venting of air therethrough. Similarly, an air supply line 118 is also defined through the top of the storage vessel 117 with valve 119 controlling air communication therethrough.
A clean fluid outlet 124 is extended through the lowermost end of the storage vessel 117, but above the seal 123, with clean fluid valve 125 disposed thereon to control the flow of clean fluid therethrough. The clean fluid outlet line 124 extends to the input to the selected industrial operation.
The purge vessel 129 receives below the seal 123 an air vent line 126 with air vent line value 127 thereon to control the venting of air therethrough.
At the lowermost end of the purge tank 129 is received the end of the purge line 106 extending from the top of the first chamber 102, with fluid flow therethrough controlled by means of valve 108 thereon. A second air supply line 130 is also communicating with the lowermost end of the purge tank 129 with valve 131 extending thereon.
As shown in FIG. 1, fluid to be cleaned which contains contaminate particulate matter passes through dirty fluid inlet 110 through open valve 111 thence into the first chamber 102 where it passes through the disposable cartridge filters 105 from the exterior to the interior thereof, thence through the clean fluid line 112.
In order for there to be effective utilization of all of the surface area of the disposable cartridge filters 105, the fluid level of the dirty fluid within the first chamber 102 should be above the uppermost end of the disposable cartridge filters 105, at the level 132 (FIG. 2).
In order to avoid the formation of a substantially non-porous solids filter cake around the exterior of the cartridge filters 105, the flow rate of the dirty fluid through the inlet 110 should be controlled such that it is from between about 0.19 ml per square inch of cartridge filter area per minute to about 1.73 ml per cartridge square inch of filtering area per minute, and preferably will be maintained at about 0.575 ml per square inch of cartridge filter area per minute and this can be readily calculated by those skilled in the art knowing the volume of the first chamber, the surface area of the cartridge filters 105, the content of the contaminate particulate matter, the composition of the fluid to be cleaned, and by appropriately throttling the valve 111.
As an example of determination of optimal flow rates for the present invention, if the selected fluid is tap or other water weighing 8.33 lbs. per gallon, and the solids concentration in such water is 10,000 parts per million, the optimal flow rate will be 0.575 ml per square inch of filter surface area per minute. If the selected fluid is salt water weighing 16 lbs. per gallon, and the solids concentration is 10,000 parts per million, the optimal flow rate will be 0.250 ml per square inch of filter surface area per minute. If the selective fluid is tap or other water weighing 8.33 lbs. per gallon, and the solids concentrations is 1,000 parts per million, the optimal flow rate will be 1.250 ml per square inch of filter surface per minute.
Throttling of the valve 111 to effect optimal flow rate can be made by incorporation of a conventional flow meter which may be affixed to the inlet line 110 or the clean fluid line 112 and the valve 111 or 113 throttled in accordance with the readings of the flow meter.
As shown in FIG. 1, the controlled fluid line valve 113 is in closed position to permit the filling of the first chamber 102 to the level 132, with the air vent valve 114a being open to vent air and the purge valve 107 being closed. The drain line valve 116 is also, of course, closed. During the filling of the first chamber 102 through the dirty fluid line 110, all other valves in the filtering system 100 will be closed.
Now, with reference to FIG. 2, subsequent to providing the fluid level in the first chamber 102 to the level 132, the valve 113 of the clean fluid line 112 is opened and the air vent valve 121 of the storage vessel 117 is open to permit clean fluid to be transmitted through the clean fluid line 112 into the clean fluid storage vessel 117.
Subsequent to the filling of the clean fluid storage vessel with clean fluid 133, the clean fluid outlet valve 125 is open to permit gravity draining, or pumping, if necessary, of clean fluid 133 from the interior of the storage vessel 117 through the clean fluid outlet line 124 to the particular industrial application at hand.
When it is desired to clean the disposable cartridge filters 105, the clean fluid 133 within the storage vessel 117 may be utilized to clean the cartridge filters 105 in the first chamber 102. The clean fluid outlet valve 125 is closed, and the air supply valve 119 is opened. The air vent line valve 121 at the uppermost end of the storage vessel 117 is closed and the purge valve 107 at the uppermost end of the first vessel 101 is opened, together with valve 108 at the lowermost end of the purge tank 129. Now, air within the air supply line 118 will be pumped through the storage vessel 117 to move the clean fluid 133 therein through the clean fluid line 112 through the interior of the disposable cartridge filters 105 to their exterior to remove any filter cake or contaminate particulate matter from around the exterior of the disposable cartridge filters 105, with excess fluid and some of the contaminate particulate matter therein passing through the purge line 106 to within the purge tank 129. Venting of the purge tank 129 is effected by opening of the air vent 127 to the air vent line 126 in communication therewith.
Now with reference to FIG. 5, any fluid within the purge tank 129 as a result of the cleaning action of the disposable cartridge filters 105, as described above, may also be cleaned by opening the air supply valve 131 to the air supply line 130 at the lowermost end of the purge tank 129, opening the air vent line valve 121 at the uppermost end of the storage vessel 117, closing the air supply line valve 119 at the uppermost end of the storage vessel 117, and recycling such fluid within the tank 129 through the purge line 126 to the interior of the first chamber 102 then through the disposable cartridge filters 105, and the clean fluid line 112 to the clean fluid storage vessel 117. Solids 134 within the second chamber 103 will be contained within the second chamber 103 around the exterior of the auxiliary filtering means 109.
Now with reference to FIG. 6, the resultant clean fluid in the storage vessel 106 will be moved to the purge tank 129 by opening of the valve 122 and the air vent 127 of the purge tank 129. Both the air supply valve line 131 and the valve 108 at the lowermost end of the purge tank 129 will have been subsequently closed. The clean fluid valve 113 will also be closed, and the dirty fluid inlet valve 111 will be closed.
Now with reference to FIG. 7, fluid then placed within the purge tank 129 may be filtered a second time by opening the air supply valve 131, and purge valve 108, together with purge valve 107 and by closing the valve 122 on the seal 123. The flow of fluid is as indicated in the drawing.
Subsequent to the operation shown in FIG. 7, normal flow operation may be effected by manipulating the valves as indicated in FIG. 8.
Upon completion of the filtering operation for the industrial fluid, the solids 134 within the second chamber 103 may be separated from fluid by opening the drain line 115 by manipulating the valve 116 to open position. The auxiliary filter means 109 will separate the solids from the fluid to permit only clean fluid to pass through the drain line 115. Subsequently, the second chamber 103 may be disengaged from the first chamber 102, such as by means of unthreading threads (not shown), removal of sealing clamps, or the like, separating the first and second chambers 102, 103 and the solids 134 manually or otherwise removed from the second chamber 103. In such operation, the respective valves of the filtering system 100 are shown in the indicated positions of FIG. 9.
A feature of the present invention is that the back wash cleaning operation is performed at a comparatively low pressure level which abates exposure of the sensitive paper-like disposable cartridge filters to deterioration caused by conventional high pressure environments. In the present invention, the cleaning procedure is effected at low pressure on the order of no more than about 40 p.s.i.
While it is preferred in the present invention to hydraulically remove filter cake and follow such hydraulic removal by cleaning of the disposable cartridge filter by introducing a gas through the interior to the exterior of the cartridge filter, the cleaning procedure may also be effected by using either a liquid, such as water, or a water with an appropriate solvent or the like or by simply introducing a gas, such as air, through the interior to the exterior of the cartridge filter to remove substantially all of any filter cake from the disposable cartridge filter.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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Method and apparatus are provided for treating and removing particulate matter from fluid circulatable into, through and out of an industrial operation, and for cleaning a disposable cartridge filter used therein. In treatment of fluid, the fluid is circulated in a flow path and is introduced into a filter vessel having a disposable cartridge filter. The fluid flows through the cartridge filter at a rate of flow insufficient to produce a buildup of a substantially non-porous solids filter cake around the exterior of the cartridge filter. The clean fluid is circulated to the industrial operation. The cleaning method and apparatus includes a storage vessel in selective fluid communication with the interior of the first vessel such that clean fluid may be flowed from the storage vessel into the interior of the cartridge filter then through and thereafter exterior of the cartridge filter to effectively remove the particulate matter deposited on or around the exterior of the cartridge filter.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a national stage entry of PCT/IB2010/053363 filed Jul. 23, 2010, under the International Convention, claiming priority over FR 0955238 filed Jul. 27, 2009.
BACKGROUND OF THE INVENTION
This invention relates to a set comprising an intervertebral implant for immobilising a vertebra with respect to another and an instrument for installing this implant.
The invention also relates to a surgical method for immobilising a vertebra with respect to another.
It is well known to immobilise two vertebrae one with respect to another by means of an intervertebral implant in a rigid material, forming a cage defining a housing, this housing being designed to receive one or more bone grafts and/or cancellous bone chips. In some cases, the bone grafts and/or the cancellous bone chips can also be placed about the implant. The implant can restore a proper separation of the vertebrae and prevent a crash of a chip or more than one chip thereof. The immobilisation of the vertebrae with respect to the implant is achieved by the growth of bone cells on the one hand through the graft or grafts and/or chips, but also on each side of the implant, leading to what is termed a “merger” of the two vertebrae.
Some intervertebral implants have a reduced width, allowing their positioning through a posterior approach, on each side of the spinal cord. It is then generally necessary to position two implants, one on the left side of the spinal cord and the other on the right side.
This technique has the drawbacks of being relatively risky to implement, involving achieving a bone resection of the vertebra near the spinal cord, and forcing the use of reduced width implants, allowing only a small area of contact of the grafts with the vertebrae.
To overcome these drawbacks, it is possible to position an intervertebral implant by anterior approach. The approach being wider than the posterior approach, such an implant can have such a shape that it extends over a major portion of the surface of a vertebral plateau, and can therefore contain one or more grafts with a significant contact surface with the vertebral plateaus, which is a prerequisite for successful spinal fusion. An initiation through an anterior approach, however, has the disadvantage of revealing certain anatomical structures (in particular veins and arteries) that the orthopaedic surgeon or neurosurgeon is not accustomed to mobilise. This approach will therefore not be possible for a spine surgeon unless he is assisted by a colleague whose specialty is, for example, vascular surgery.
An alternative that allows solving temporarily the drawbacks of the two previous techniques consists in placing a single intervertebral implant positioned on the front side of the vertebra, occupying only a marginal surface of the intervertebral space and thereby freeing a significant surface area for the positioning of one or more grafts and/or bone chips. The implant is positioned by the posterior, side or intermediate approach between side and posterior, therefore slightly invasive. Document FR 2 923 158 describes an instrument for the introduction and implementation of such an implant, comprising a rod whose distal end is provided with means for mounting the implant, this instrument allowing (i) retaining the implant in the extension of the rod to achieve the introduction of the implant into the intervertebral space, with possible impaction, (ii) operating, once the introduction is achieved, a side pivoting of the implant with respect to the rod, in order to place the implant in the anterior position of the intervertebral space, and (iii) releasing the implant once the latter is in the position thereof of positioning in order to allow the removal of the instrument. Said mounting means comprise an articulated head equipped with a threaded rod and the implant comprises a threaded boring channel for screwing this implant on this articulated head.
Document WO 2008/019393 describes a similar instrument, connected to the implant by a double jaw, which in addition comprises a cable allowing to direct the implant with respect to the instrument.
The known instruments do not satisfy fully. In fact, the release of the implant can be difficult and achieve and lead to a change of the position of the implant during withdrawal of the instrument. The side pivoting of the implant with respect to the rod can be difficult to achieve or to control accurately, which can lead to a non optimal positioning of the implant in the intervertebral space. There is also a risk of longitudinal pivoting of the implant about itself during the operation of introducing this implant, leading to a faulty positioning of the implant; this faulty positioning is difficult to overcome once the implant is pivoted laterally or released.
OBJECTS OF THE INVENTION
The purpose of this invention is to remedy these drawbacks as a whole.
The main purpose thereof is therefore to provide a set that allows easy release of the implant, without substantial change of the position of the implant during withdrawal of the instrument.
Another purpose of the invention is to provide a set that allows achieving easy side pivoting of the implant with respect to the instrument and to control accurately this pivoting.
Still another purpose of the invention is to provide a set eliminating or significantly reducing the risk of longitudinal pivoting of the implant itself in the operation of introduction of this implant.
An additional purpose of the invention is to provide a set that allows correcting easily the position of the implant if this position proves to be faulty.
SUMMARY OF THE INVENTION
The involved set comprises, in a manner known thereto by document FR 2 923 158, an intervertebral implant allowing to immobilise a vertebra with respect to another, and an instrument for installing this implant; the implant comprises a longitudinal end designed to be connected to the instrument, having a cavity, and is connected to two flexible strands each extending from one of the longitudinal ends thereof; the instrument comprises a rod having a free distal end, on which the implant is designed to be removably mounted, this free distal end being designed to be engaged in said cavity of the implant, with possibility of pivoting of the implant with respect to the instrument; the set also comprises means for mounting the implant on said free distal end of the instrument.
According to the invention,
said free distal end of the instrument rod is rounded; the instrument comprises releasable means, adapted, in a position, to retain the flexible strands in strain on each side of said rod, according to equivalent strains, and, in another position, to fully free these strands; and the means for mounting the implant on said distal end of the instrument are constituted by the two flexible strands held in strain by said releasable means, this retaining in strain allowing to achieve mounting of the implant on this distal end, while retaining this distal end engaged in said cavity of the implant; releasing of the strain of the strands makes it possible to exercise a traction on either one of these strands to allow a side pivoting of the implant with respect to the distal end of the rod; the full release of the strands allows releasing the implant with respect to the instrument.
Retention of the strands on each side of the rod, as equivalent strains, thus allows positioning the implant on the distal end of the rod, in the extension of this rod, and therefore make it possible introducing the implant into the intervertebral space by using the instrument. During this introduction, the strands extend along the rod and do not hinder this introduction of the implant; once the implant inserted, the retaining means for straining the strands are released, making possible the exercise of a traction on either one of these strands in order to allow achieving a precise and controlled side pivoting of the implant about the distal end of the rod, the rounded shapes of this distal end of the cavity and the implant allowing to guide this side pivoting; once this pivoting achieved, the instrument is easily separated from the implant and can be therefore be withdrawn without risk of substantial change in the position of the implant.
The strands can also be used to withdraw the implant outside of the intervertebral space in the case where this implant would not be in the desired position.
The strands can also be used advantageously to guide one or more grafts and/or cancellous bone chips into the intervertebral space and to surround this or these grafts and/or chips, inasmuch being connected to each other, for example by knotting, so as to ensure retention of this or these grafts and/or chips among the vertebrae.
Preferably, the implant and the instrument comprise connecting means adapted to immobilize the implant with respect to the instrument about the longitudinal axis of said rod of the instrument, these connecting means being engaged when the implant is mounted on said rod in the longitudinal extension thereof.
These connecting means can thus eliminate the risk of longitudinal pivoting of the implant about itself during operation of introducing of this implant.
Preferably, said connecting means are arranged in the shape of a groove or a rib arranged at the cavity of the implant, extending in the plane of side pivoting of the implant with respect to said rod, and in the shape of a rib or a groove arranged at the distal end of the rod of the instrument, also extending in the pivoting plane of the implant with respect to said rod, the rib being designed to be engaged in the groove with the possibility of sliding.
To ensure perfect immobilisation of the implant in the extension of said rod of the instrument during operation of introducing the implant, the implant and this rod may comprise two respective holes aligning when the implant is in the introduction position with respect to said rod, the instrument further comprising a pin adapted, in this introduction position, to be engaged removably in these respective holes of the instrument and of the implant.
According to an embodiment of the invention, in this case, the hole of the implant outlets into said cavity, and the rod of the instrument is tubular and the hole that it comprises outlets axially into the distal end thereof.
The pin is thus engaged in the rod and does not hinder the introduction of the implant.
Advantageously, the hole of the implant or the hole of said rod is tapped and the distal end of the pin is threaded, this pin being in a position to be screwed into one or the other of those holes.
Retention of the implant in the introduction position is thus perfectly ensured by this screwing.
Preferably, said rod of the instrument comprises at least one pass-through guiding a flexible strand connected to the implant.
This or these pass through allow to retain the strands along the rod of the instrument.
Advantageously, in this case, this rod comprises a pass-through on the side wherein the implant is designed to be pivoted laterally, and located slightly behind the distal end of this rod, that is to say at a distance in the order of one to two centimetres from this end.
This pass-through allows retaining against the rod the strand located on the side thereto, in such a manner as not to interfere with the anatomical elements upon exerting thereto traction to achieve side pivoting of the implant.
According to a possible embodiment of the invention, said releasable means comprise at least one element mounted pivotally on the instrument, movable between a retain strain position, wherein it is folded back against the instrument and tightens a strand between the latter and the instrument, and a strain releasing position, wherein it is kept away from the instrument and allows sliding of the strand between the latter and the instrument.
Advantageously, in this case, said element comprises a lumen crossing it through, extending between a central area of this element and an end area of this element; a pin of the instrument, forming the pivot axis of this element, is engaged in said lumen with the possibility of pivoting and of sliding therein; said element is thus capable of being slid with respect to the instrument in such a way that the pin forming the axis is placed at the end of the lumen located towards the central area of the element, thereby immobilising this element to pivot with respect to the instrument; this same element is also capable to be slid with respect to the instrument in such a manner that said pin forming the axis is placed at the end of the lumen located towards the end area of the element, thereby allowing the pivoting of this element with respect to the instrument and corresponds to said strain releasing position.
An easy actuation of the instrument is thus obtained along with a simple structure and easy to sterilise.
According to another possible embodiment of the invention, the instrument comprises a ring axially mobile mounted thereon, moving between a first axial position for retaining strain, wherein the ring tightens a strand or the two strands between itself and the instrument, and a second axial position, for releasing strain, wherein the ring allows sliding of the strand or strands between itself and the instrument. In particular, this ring can be screwed and unscrewed on a grip handle that comprises the instrument, this screwing/unscrewing allowing the latter passing-through said first axial position to said second axial position and vice versa.
The invention also relates to a surgical method for immobilizing a vertebra with respect to another, comprising the steps consisting of:
using the set as specified above; engaging the implant on the distal end of the instrument rod and then actuate said releasable means so as to place the strands in strain and retain these strands in strain, in order to achieve setting of the implant on the distal end of the instrument rod; inserting the implant between the vertebral plateaus of two vertebrae by means of said instrument, part of these strands exceeding outside the patient; actuating said releasable means so as to release at least partially the strain of these strands; achieving a side pivoting of the implant with respect to the distal end of said rod by using a strand or the two strands for directing and positioning the implant in the intervertebral space or to correct the position of the implant in the Intervertebral space; fully unlocking the strands of the instrument to leave the implant in place in the intervertebral space, and withdraw the instrument.
The method may comprise the step consisting of withdrawing the implant outside the intervertebral space in the case where the implant would not be in the desired position, by traction on the strands.
The method may also comprise the steps consisting of:
introducing one or more grafts and/or cancellous bone chips between the strands, in the intervertebral space; and using the strands in such a manner as to retain this graft, or these grafts, and/or chips between the vertebrae and compact them.
The invention will be better understood, and other characteristics and advantages thereof will become evident, with reference to the annexed schematic drawing, representing, by way of non exhaustive examples, one embodiment of the intervertebral implant that it relates, and two embodiments of the instrument that it relates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the implant;
FIG. 2 is a view similar to FIG. 1 with central longitudinal cross-section in the direction of the thickness thereof;
FIG. 3 is a top view of the instrument, in a disassembled state, according to a first embodiment;
FIG. 4 is a view of the instrument similar to FIG. 3 , in the mounted state and partly in cross-section, with the mounting of the implant on the distal end of a rod that comprises this instrument; the implant is placed in a introduction position into an intervertebral space, and retaining elements in strain of flexible strands connected to this implant are in a position of releasing the strain of these strands;
FIG. 5 is a view of the instrument and the implant similar to FIG. 4 , except that said strands are in strain and that said retaining elements in strain are in a folded back position against the grip handle of the instrument but are not immobilised with respect to this grip handle;
FIG. 5A is a partial view of the instrument similar to FIG. 5 , on an enlarged scale;
FIG. 5B is a partial view of the instrument similar to FIG. 5 , with said retaining elements in strain in immobilisation position with respect to the grip handle of the instrument;
FIG. 6 is a view of the implant and of the distal part of the instrument rod, similar to FIG. 5 , on an enlarged scale;
FIG. 7 is a view of the instrument and of the implant similar to FIG. 4 , but with the implant placed in a side pivoting position with respect to the rod of the instrument, and the retaining elements in strain a releasing position of the strain of the strands;
FIG. 8 is a view of the implant and of the distal part of the rod of the instrument, similar to FIG. 7 , on an enlarged scale, the implant being in a position of full side pivoting with respect to the rod instrument;
FIGS. 9 to 11 are top views of the implant and of the instrument during different successive steps of positioning of the implant between the plateaus of the two vertebrae; and
FIG. 12 is a cross-section top view of the instrument, according to a second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 9 to 11 represent a set 1 comprising an intervertebral implant 2 allowing immobilising a vertebra 100 with respect to the overlying vertebra 100 and an instrument 3 of positioning this implant 2 between the plateaus 101 of the two vertebrae.
As shown more particularly in FIGS. 1 and 2 , the implant 2 is designed to be inserted between the plateaus 101 of the two vertebrae 100 to be immobilised and is connected to a flexible link or ligament 6 forming two strands 6 a , 6 b exceeding from this implant.
The implant 2 has a curved shape substantially corresponding to the curvature shown by the anterior surface of the element of a vertebra 100 and such length that it occupies, once positioned in place, between the plateaus 101 , a portion of the area of these plateaus along this anterior approach (see FIGS. 9 to 11 ). Moreover, it has such a width that it can be introduced into the intervertebral space to be treated by posterior approach, as shown, by side approach or intermediate approach between the posterior approach and the side approach.
As shown more particularly in FIG. 1 , the implant 2 has faces 10 designed to come into contact with the plateaus 101 , equipped with series of triangular cross-section ribs 11 . These ribs 11 provide support grip without slipping of the implant 2 against the plateaus 101 .
The implant 2 also comprises an inner housing 12 discharging in the faces 10 . This housing 12 is designed to receive one or more grafts and/or cancellous bone chips before its introduction into the intervertebral space.
It also comprises a hemispherical-shaped cavity 15 , arranged in the longitudinal end thereof designed to be connected to the instrument 3 , a threaded boring channel 16 discharging into the bottom of the cavity 15 , substantially coaxially thereto, and a curved groove 17 . As can be seen in FIGS. 1 and 2 , this groove 17 extends perpendicular to the thickness of the implant 2 , substantially halfway up thereto, from the anterior side edge of the cavity 15 up to beyond the boring channel 16 , and the curvature thereof is cantered on the centre of the cavity 15 .
Moreover, the implant 2 comprises two internal conduits 18 , 19 arranged at its convex surface, enabling the sliding engagement of the ligament 6 , one of these conduits 18 being located at said longitudinal end of the implant 2 designed to be connection to the instrument 3 , and the other conduit 19 being located at the side of the other end of the implant 2 . The ligament 6 thus extends along the convex surface of the implant 2 and forms the strand 6 a at the longitudinal end of the implant 2 designed to be connection to the instrument 3 , and the strand 6 b at the opposite end, as can be seen in FIG. 6 or 8 .
In particular, the ligament 6 can be formed by a braided implantable fibrous material, for example polyester. It is preferably flattened and has a width substantially corresponding to the height of the intervertebral space to be restored, or slightly lower with respect to this height.
With reference to FIGS. 3 to 6 , it is evident that the instrument 3 comprises a body 20 , a pin 21 and two releasable elements 22 for retaining the strands 6 a , 6 b under strain.
The element 20 is tubular. It comprises a gripping grip handle 25 and a rigid rod 26 .
The grip handle 25 forms two diametrically opposite grooves 27 , extending in the plane of the side pivoting of the implant 2 with respect to the instrument 3 (which is the plane of the cross-sections shown in FIGS. 4 to 8 ) and at which level the elements 22 are mounted in a pivoting manner.
The rod 26 comprises a rounded distal end 28 , substantially spherical, perforated axially by a boring channel 29 and comprising a curved projecting rib 30 extending laterally in the said plane, as shown in FIG. 6 or 8 . The distal end 28 is designed to be engaged in the cavity 15 and the rib 30 is designed to be received in the groove 17 with possibility of sliding. The hole 16 is opposite the boring channel 29 in said introduction position for the implant 2 shown in FIGS. 5 and 6 .
The rod 26 also comprises two pass through 31 , 32 on two diametrically opposite sides, also located in said plane. One of these pass through 31 is placed on the side onto which the implant 2 is designed to be pivoted laterally, slightly backward from the distal end 28 , that is to say at a distance in the order of one to two centimetres from this end; the other pass-through 32 is positioned further backward from this end 28 .
The pin 21 is threaded at one end and comprises a gripping head 34 at the other end thereof. It is designed to be engaged in the body 20 by the threaded end thereof, up to the through-pass of the boring channel 29 and to be screwed into the threaded hole 16 of the implant 2 . In the position of full screwing shown in FIGS. 4 to 6 , the head 34 abuts against the grip handle 25 of the body 20 , ensuring the immobilisation of the implant 2 with respect to the instrument 3 in said introduction position.
As shown in greater detail in FIG. 5A , each releasable element 22 comprises a detachable lumen 35 crossing it from side to side, extending between a central area of this element 22 and an end area of this element; a pin 36 of the Instrument 3 , forming the pivoting axis of this element 22 , is engaged in the lumen 35 with the possibility of pivoting and sliding therein, said element 22 is thus capable to be slid with respect to the instrument in such a manner so that pin 36 be placed at the end of the lumen 35 located towards the central area of the element 22 , thereby immobilising this element 22 pivoting with respect to the instrument 3 (see FIG. 5B ); this very element 22 is also capable to be slid with respect to the instrument 3 in such a manner that the pin 36 is placed at the end of the lumen 35 located toward the end area of the element 22 , thereby allowing pivoting of this element with respect to the instrument 3 (see FIGS. 5 and 5 a ).
Each element 22 is thus movable between a retaining position of the strain shown in FIG. 5 (unlocked position) or 5 B (locked position), wherein it is folded back against the instrument and tightens a strand 6 a , 6 b between itself and the grip handle 25 , and a releasing position the strain shown in FIG. 4 , wherein it is kept away from the grip handle 25 and allows sliding of the strand 6 a , 6 b between itself and the grip handle 25 .
To facilitate the handling thereof, each element 22 comprises an eminence above the lumen 35 , forming a support for a thumb of the user, and a ribbed anti-slip surface, outside from this eminence.
In practice, as shown in FIG. 9 , the housing 12 is lined with one or more grafts and/or chips of bone and the implant 2 , in the setting phase shown in FIGS. 5 and 6 , under strain of the strands 6 a , 6 b , is introduced into the intervertebral space by using the instrument 3 , by posterior, side or intermediate approach, with possible impaction.
During this introduction, the rib 30 is engaged in the groove 17 , thereby preventing any risk of longitudinal pivoting of the implant 2 with respect to the instrument 3 , which could lead to faulty positioning of this implant 2 .
Once the latter is introduced, the pin 21 is unscrewed and the strain of the strands 6 a , 6 b is slightly released by manoeuvring the elements 22 , to allow side pivoting of the implant 2 with respect to the instrument 3 , as shown FIG. 10 .
The strain of the strands 6 a , 6 b is then released, making possible the exercise of strain in one or the other of these strands to allow a precise and controlled side pivoting of the implant 2 with respect to the distal end 28 of the rod 26 .
Once the implant 2 is in place on the anterior side of the end plateaus 101 ( FIG. 10 ), the strands 6 a , 6 b are released from the instrument 3 and the latter is withdrawn ( FIG. 11 ).
In the case where the implant 2 would not be in the desired position, the strands 6 a , 6 b can be used to remove the implant 2 out of the intervertebral space and repeat the operations of introduction and positioning.
These strands 6 a , 6 b can be used advantageously to guide one or more grafts and/or cancellous bone chips into the intervertebral space and to surround this, or these, grafts and/or chips, by being connected to one another, for example by knotting, in order to ensure retaining of this, or these, grafts and/or chips between the vertebrae.
FIG. 12 shows a set 1 identical to that described above, except that in this set, the elements 22 are replaced by a ring 40 axially movable on a conical area of the instrument 3 , this ring 40 being movable between a first axial position, of retaining the strain of the strands 6 a , 6 b , wherein the ring tightens the two strands between itself and the instrument 3 , and a second axial position, of releasing the strain, wherein it allows sliding of the strands 6 a , 6 b between itself and the instrument 3 .
It is evident from the foregoing that the invention provides a set 1 showing the key advantages of (i) allowing an easy release of the implant 2 , without substantial change in the position of this implant during withdrawal of the instrument 3 , (ii) achieving easily the side pivoting of the implant 2 with respect to the instrument 3 and controlling precisely this pivoting, (iii) eliminating or greatly reducing the risk of longitudinal pivoting of the implant 2 thereon during the introduction operation of this implant, and (iv) allowing to correct easy the position of the implant 2 if this position proved to be defective.
The invention has been described above with reference to embodiments given solely by way of an example. It is understood that it is not limited to these embodiments but that it extends to all other embodiments covered by the hereby annexed claims.
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This set comprises an intervertebral implant ( 2 ) for immobilising a vertebra ( 100 ) with respect to another and an instrument ( 3 ) for installing this implant; the implant ( 2 ) comprises a longitudinal end designed to be connected to the instrument ( 3 ), and the instrument ( 3 ) comprises a rod ( 26 ) having a free distal end ( 28 ), wherein the implant ( 2 ) is designed to be removably mounted. According to the invention: —said free distal end ( 28 ) of the instrument rod ( 26 ) is rounded; —the instrument ( 3 ) comprises releasable means ( 22 ) adapted, in a position, to retain the flexible strands ( 6 a, 6 b ) in strain on each side of said rod ( 26 ), according to equivalent strains, and, in another position, to fully free these strands ( 6 a, 6 b ); and—the means for mounting the implant ( 2 ) on said distal end ( 28 ) are constituted by the two flexible strands ( 6 a, 6 b ) held in strain by said releasable means ( 22 ), this retaining in strain allowing to achieve mounting of the implant ( 2 ) on this distal end ( 28 ), while retaining this distal end ( 28 ) engaged in a cavity ( 15 ) of the implant ( 2 ).
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BACKGROUND
1. Field of the Invention
The present invention relates to the design of programming languages for computer systems and associated development tools. More specifically, the present invention relates to a method and an apparatus for associating metadata attributes that do not affect program execution with program elements.
2. Related Art
It is often desirable for programmers to annotate program elements, such as fields, methods, and classes, as having particular attributes that indicate that they should be processed in special ways by development tools, deployment tools, or run-time libraries. We call such annotations “metadata.” Ideally, this metadata should be easily accessible at development time, deployment time, and run time.
Metadata has many uses. Custom tools may use metadata to generate auxiliary source files to be used in conjunction with the source file containing the annotation. For example, a stub generator can generate remote procedure call stubs based on annotations indicating that certain methods are designed for remote use.
A number of existing mechanisms presently allow programmers to associate metadata with programs. For example, the C++ programming language has a preprocessor directive called “#pragma” that affects the actions of the compiler as it compiles the program. Some uses of this directive associate metadata with the program. For example, this directive's COPYRIGHT function associates a copyright string with a program. The copyright string is then embedded in the object code where it can be read with the Unix strings utility. However, the C++ #pragma directive does not allow the programmer to associate arbitrary metadata, does not allow metadata to be associated with particular program elements, and does not allow metadata to be read at run time.
JAVA's doclet API has been used to associate metadata with program elements by various tools such as ejbdoclet, webdoclet, ejbgen, and icontract. Although this usage does allow the programmer to associate arbitrary metadata with particular program elements, it does not allow metadata to be read at run time, nor does it provide a mechanism to manage the namespace of metadata attributes.
Hence, what is needed is a facility that allows programmers to associate arbitrary metadata with arbitrary program elements in a manner that allows the metadata to be accessed by development tools, deployment tools, and programmatically at runtime without the limitations of the mechanisms described above.
SUMMARY
One embodiment of the present invention provides a system for associating metadata attributes with program elements. During operation, the system receives source code containing syntactic elements that specify metadata attributes for program elements, wherein the metadata attributes do not affect program execution. The system then parses the source code to obtain the metadata attributes. Next, the system associates the metadata attributes with corresponding program elements and determines values associated with the metadata attributes. Finally, the system incorporates the metadata attributes, including identifiers for the associated values and the associated program elements, into object code for the program, thereby allowing the metadata attributes to be accessed from the object code.
In a variation on this embodiment, a metadata attribute for a program element is expressed in the source code as a modifier for a declaration for the program element.
In a variation on this embodiment, a given metadata attribute can contain nested metadata attributes.
In a variation on this embodiment, a given metadata attribute is defined by a corresponding class for the given metadata attribute.
In a variation on this embodiment, the corresponding class for the given metadata attribute is located in a package named according to a unique package naming convention. This allows parties to define their own metadata attributes that are guaranteed not to interfere with attributes defined by other parties.
In a variation on this embodiment, the system additionally validates a given metadata attribute using validation criteria from an object file for a class associated with the given metadata attribute.
In a variation on this embodiment, determining values associated with the metadata attributes involves evaluating constant expressions.
In a variation on this embodiment, the object code for the program includes one or more class files for the program.
In a variation on this embodiment, a program element can include, a method, a class, and or a field.
One embodiment of the present invention provides a system for accessing metadata attributes associated with program elements. During operation, the system receives object code for a program, wherein the object code contains metadata attributes for program elements; these the metadata attributes do not affect program execution. Next, the system stores the object code in a memory buffer without loading the object code for program execution. The system then accesses the metadata attributes for the program elements from the object code through an application programming interface (API).
In a variation on this embodiment, the API includes: a method that returns a specified attribute of a specified element; a method that returns all attributes of a specified element; a method that returns all elements having a specified attribute; and a method that returns all elements having a specified attribute-value pair.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a computer system in accordance with an embodiment of the present invention.
FIG. 2 illustrates the structure of a compiler in accordance with an embodiment of the present invention.
FIG. 3 is a flow chart illustrating the process of incorporating metadata attributes for program elements into object code in accordance with an embodiment of the present invention.
FIG. 4 is a flow chart of the process of accessing metadata attributes associated with program elements in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
The data structures and code described in this detailed description are typically stored on a computer-readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs) and DVDs (digital versatile discs or digital video discs), and computer instruction signals embodied in a transmission medium (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, such as the Internet.
Computer System
FIG. 1 illustrates a computer system 100 in accordance with an embodiment of the present invention. As illustrated in FIG. 1 , computer system 100 includes processor 102 , which is coupled to a memory 112 and to peripheral bus 110 through bridge 106 . Bridge 106 can generally include any type of circuitry for coupling components of computer system 100 together.
Processor 102 can include any type of processor, including, but not limited to, a microprocessor, a mainframe computer, a digital signal processor, a personal organizer, a device controller and a computational engine within an appliance. Processor 102 includes a cache 104 that stores code and data for execution by processor 102 .
Processor 102 communicates with storage device 108 through bridge 106 and peripheral bus 110 . Storage device 108 can include any type of non-volatile storage device that can be coupled to a computer system. This includes, but is not limited to, magnetic, optical, and magneto-optical storage devices, as well as storage devices based on flash memory and/or battery-backed up memory.
Processor 102 communicates with memory 112 through bridge 106 . Memory 112 can include any type of memory that can store code and data for execution by processor 102 .
As illustrated in FIG. 1 , memory 112 contains compiler 116 . Compiler 116 converts source code 114 into object code 118 . In doing so, compiler 116 incorporates metadata attributes that are specified by syntactic elements within source code 114 into object code 118 . This process is described in more detail below with reference to FIG. 3 .
Incorporating metadata into object code enables development tool 120 to access the metadata attributes from object code 118 through an API. This process is described in more detail below with reference to FIG. 4 .
Note that although the present invention is described in the context of computer system 100 illustrated in FIG. 1 , the present invention can generally operate on any type of computing device. Hence, the present invention is not limited to the specific implementation of computer system 100 illustrated in FIG. 1 .
Compiler
FIG. 2 illustrates the structure of compiler 116 in accordance with an embodiment of the present invention. Compiler 116 takes as input source code 114 and outputs object code 118 . Note that source code 114 may include any computer program written in a high-level programming language, such as the JAVA programming language. Object code 118 includes executable instructions for a specific virtual machine or a specific processor architecture.
Compiler 116 includes a number of components, including front end 202 and back end 206 . Front end 202 takes in source code 114 and parses source code 114 to produce intermediate representation 204 .
Intermediate representation 204 feeds into back end 206 , which produces object code 118 . Within backend 206 , intermediate representation 204 feeds through optimizer 208 , and the resulting optimized intermediate representation 209 feeds though code generator 210 which produces object code 118 .
During this process, compiler 116 incorporates metadata attributes into object code 118 as is described below with reference to FIG. 3 .
Process of Incorporating Metadata into Object Code
FIG. 3 is a flow chart illustrating the process of incorporating metadata attributes for program elements in object code in accordance with an embodiment of the present invention. The system starts by receiving source code for a program, wherein the source code contains syntactic elements that specify metadata attributes for program elements (step 302 ). Note that the metadata attributes do not effect program execution.
The program elements can include methods, classes or fields that can be associated with attributes. For example, a method can be associated with attributes, such as: (1) a remote attribute that specifies whether the method is a remote method or a local method; (2) a precondition attribute and a postcondition attribute that collectively facilitate “design by contract;” (3) a deprecated attribute which indicates that a given method is supported, but should no longer be used; or (4) a query attribute that facilitates forming a database query for an accessor method.
A class can be associated with attributes, such as: (1) an author attribute that identifies the author of the class; (2) a deprecated attribute, which indicates that the class is supported, but should no longer be used; and (3) a framework membership attribute that signifies that the class participates in a framework.
A field can have attributes, such as a persistence attribute, which indicates whether or not the field is persistent. Note that this persistence attribute can be a boolean attribute, or alternatively a multi-valued attribute that specifies a type of persistence.
Next, the system parses the source code to obtain metadata attributes (step 304 ). In one embodiment of the present invention, a metadata attribute is expressed in the source code as a modifier associated with a declaration for a program element. In this embodiment, each attribute is declared as a class. For example, an interface for a class associated with “deprecated” attribute can have the form,
interface @deprecated extends Java.lang.BooleanAttribute{ }.
The deprecated attribute is associated with a program element as a modifier for a declaration for the program element. For example, a class can be associated with both the deprecated attribute and the author “Mickey Mouse” in the following way,
@deprecated @author(“Mickey Mouse”) public static final class Foo extends Bar { public static final void main { } }.
Note that in the above example, a modifier associated with an attribute can be easily identified by “@” symbol. Also note that multiple attribute modifiers can be associated with a given declaration.
Attributes can also be nested. For example, a “remote” attribute for a class can the specified as follows,
@remote( @comstyle(“Corba”), @timeout(10), ) <<method declaration>>.
This nested remote attribute specifies that the communication style for the remote method is “Corba” and that the timeout period for the remote method is 10 seconds. Note that this information can be used by a programming tool to build a stub for the remote method.
An interface for a class that defines the nested “remote” attribute can have the form,
public interface @remote extends CompoundAttribute {
public interface @comstyle
extends java.lang.StringAttribute{ }
public interface @timeout
extends java.lang.IntAttribute{ }
. . .
}
Note that by placing the classes that define the attributes in packages named according to a unique package naming convention like the one described in Section 7.7 of the Java(tm) Language specification, Second Edition (Gosling, Joy, Steele, Bracha; Addison-Wesley 2000), the present invention can leverage off the existing namespace management features enabled by the convention. Hence, unrelated parties can define their own classes for their own attributes, and these classes can be located within their own portions of the package namespace. This allows unrelated parties to define different attributes using the same name without interfering with each other.
Next, the system determines values associated with the metadata attributes, which may involve evaluating constant expressions (step 306 ). After or during the parsing process, the system can validate the metadata attributes (step 308 ). In one embodiment of the present invention, this involves using validation criteria retrieved from an object file for a class that defines a given metadata attribute to validate the given metadata attribute.
The system then associates metadata attributes with corresponding program elements (step 310 ). The system then incorporates the metadata attributes, including identifiers for associated values and associated program elements, into object code (class files) for the program (step 312 ). In one embodiment of the present invention, the metadata attributes are stored as “class file attributes” in a JAVA class.
Process of Accessing Metadata Attributes from Object Code
FIG. 4 is a flow chart of the process of accessing metadata attributes associated with program elements in accordance with an embodiment of the present invention. This process can take place either at run time (while the class is loaded), or at design time (while the class is not loaded).
If the process takes place during run time, one embodiment of the present invention adds an accessor method to class for each primitive type attribute. For example, we can add the following accessor methods to class,
String getStringAttribute(name of attribute), and int getlntAttribute(name of attribute).
These accessor methods can be used to retrieve a string and an integer, respectively. For example, “Foo.class.getStringAttribute@author.class)” returns a string for the attribute “author” during run time. However, note that in order to do this the class literal “Foo.class” must be evaluated, which requires loading the class.
If the process takes place during design time, one embodiment of the present invention provides an application programming interface (API) to obtain metadata associated without program elements without having the load the class.
The process operates as follows. Upon receiving object code for a program (step 402 ), the process loads the object code into a memory buffer—without performing the time-consuming verification operations involved in loading the class into a virtual machine (step 404 ). Next, the process accesses metadata attributes for program elements through an API (step 406 ).
Note that API can be defined as a class. For example, the class can include methods to: (1) return a specified attribute of a specified element; (2) return all attributes of a specified element; (3) return all elements having a specified attribute; (4) return all elements having a specified attribute-value pair; (5) return a specified sub-attribute of a complex attribute; and (6) to return all sub-attributes of a complex attribute.
The foregoing descriptions of embodiments of the present invention have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended
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One embodiment of the present invention provides a system for associating metadata attributes with program elements. During operation, the system receives source code containing syntactic elements that specify metadata attributes for program elements, wherein the metadata attributes do not affect program execution. The system then parses the source code to obtain the metadata attributes. Next, the system associates the metadata attributes with corresponding program elements and determines values associated with the metadata attributes. Finally, the system incorporates the metadata attributes, including identifiers for the associated values and the associated program elements, into object code for the program, thereby allowing the metadata attributes to be accessed from the object code. Another embodiment of the present invention provides a system for accessing metadata attributes for program elements from object code through an application programming interface (API).
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FIELD OF THE INVENTION
In general, the invention relates to devices and methods for non-invasive neurostimulation of a subject's brain. More specifically, the invention relates to devices and methods for non-invasive neurostimulation of a subject's brain to effect treatment of various maladies.
BACKGROUND OF THE INVENTION
Traumatic brain injury (TBI) is a leading cause of disability around the world. Each year in the United States, about two million people suffer a TBI, with many suffering long term symptoms. Long term symptoms can include impaired attention, impaired judgment, reduced processing speed, and defects in abstract reasoning, planning, problem-solving and multitasking.
A stroke is a loss of brain function due to a disturbance in the blood supply to the brain. Every year, about 800,000 people in the United States will have a stroke. Stroke is a leading cause of long-term disability in the United States, with nearly half of older stroke survivors experiencing moderate to severe disability. Long term effects can include seizures, incontinence, vision disturbance or loss of vision, dysphagia, pain, fatigue, loss of cognitive function, aphasia, loss of short-term and/or long-term memory, and depression.
Multiple sclerosis (MS) is a disease that causes damage to the nerve cells in the brain and spinal cord. Globally, there are about 2.5 million people who suffer from MS. Symptoms can vary greatly depending on the specific location of the damaged portion of the brain or spinal cord. Symptoms include hypoesthesia, difficulties with coordination and balance, dysarthria, dysphagia, nystagmus, bladder and bowel difficulties, cognitive impairment and major depression to name a few.
Alzheimer's disease (AD) is a neurodegenerative disorder affecting over 25 million people worldwide. Symptoms of AD include confusion, irritability, aggression, mood swings, trouble with language, and both short and long term memory loss. In developed countries, AD is one of the most costly diseases to society.
Parkinson's disease (PD) is a degenerative disorder of the central nervous system, affecting more than 7 million people globally. Symptoms of PD include tremor, bradykinesia, rigidity, postural instability, cognitive disturbances, and behavior and mood alterations.
One approach to treating the long term symptoms associated with TBI, stroke, MS, AD, and PD is neurorehabilitation. Neurorehabilitation involves processes designed to help patients recover from nervous system injuries. Traditionally, neurorehabilitation involves physical therapy (e.g., balance retraining), occupational therapy (e.g., safety training, cognitive retraining for memory), psychological therapy, speech and language therapy, and therapies focused on daily function and community re-integration.
Another approach to treating the long term symptoms associated with TBI, stroke, MS, AD, and PD is neurostimulation. Neurostimulation is a therapeutic activation of part of the nervous system. For example, activation of the nervous system can be achieved through electrical stimulation, magnetic stimulation, or mechanical stimulation. Typical approaches focused mainly on invasive techniques, such as deep brain stimulation (DBS), spinal cord stimulation (SCS), cochlear implants, visual prosthesis, and cardiac electrostimulation devices. Only recently have non-invasive approaches to neurostimulation become more mainstream.
Despite many advances in the areas of neurorehabilitation and neurostimulation, there exists an urgent need for treatments that employ a combined approach, including both neurorehabilitation and neurostimulation to improve the recovery of patients having TBI, stroke, multiple sclerosis, Alzheimer's, Parkinson's or any other neurological impairment.
SUMMARY OF THE INVENTION
The invention, in various embodiments, features methods and devices for combining non-invasive neuromodulation with traditional neurorehabilitation therapies. Clinical studies have shown that methods combining neurostimulation with neurorehabilitation are effective in treating the long term neurological impairments due to a range of maladies such as TBI, stroke, MS, AD, and PD.
In one aspect, the invention features a system for providing non-invasive neuromodulation to a patient. The system includes a mouthpiece and a controller. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes control circuitry mounted within a top portion of the elongated housing for controlling electrical signals delivered to the electrodes. The mouthpiece also includes a cable with a first end attached to the anterior portion of the elongated housing and having a connector at a second end for connecting to a controller, the cable delivering electrical current to the electrodes via the control circuitry. The controller includes an elongated u-shaped element configured to rest upon a patient's shoulders. The controller also includes an electronic receptacle located at a terminus of the u-shaped element connecting to the cable. The controller also includes a microcontroller located within the three-dimensional u-shaped element, the microcontroller configured to send electrical control signals to the mouthpiece, the electrical control signals determining an amplitude and duration of electrical signals delivered to the patient's tongue.
In some embodiments, the system also includes an accelerometer for measuring an activity level of the patient. In some embodiments, the system also includes a data logger for logging information related to the activity level of the patient. In some embodiments, the system also includes tongue sense circuitry for determining if a patient's tongue is in contact with the plurality of electrodes located on the bottom portion of the mouthpiece. In some embodiments, the system also includes a real time clock for determining a total time of usage of the mouthpiece. In some embodiments, the system also includes a battery for providing a current to the mouthpiece. In some embodiments, the system also includes an optical indicator that indicates a power level of the battery. In some embodiments, the system also includes an audio indicator that can warn the patient when the remaining battery charge is inadequate to complete a therapy session. In some embodiments, the exterior top surface of the elongated housing is planar. In some embodiments, the printed circuit board is mounted to a middle or top portion of the elongated housing. In some embodiments, the control circuitry is mounted within a middle or top portion of the elongated housing. In some embodiments, the cable is permanently attached to the controller and is removably attached to the mouthpiece.
In another aspect, the invention features a system for providing non-invasive neuromodulation to a patient. The system includes a mouthpiece and a controller. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a printed circuit board mounted to the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes control circuitry mounted within the elongated housing for controlling electrical signals delivered to the electrodes. The mouthpiece also includes a first communication module delivering electrical current to the electrodes via the control circuitry. The controller includes an elongated u-shaped housing configured to rest upon a patient's shoulders. The controller also includes a second communication module within the housing coupled to and in communication with the first communication module. The controller also includes a microcontroller located within the housing and configured to exchange electrical signals with the mouthpiece, the electrical signals determining an amplitude and duration of electrostimulation energy pulses delivered to the patient's tongue.
In some embodiments, the system also includes an accelerometer for measuring an activity level of the patient. In some embodiments, the system also includes a data logger for logging information related to the activity level of the patient. In some embodiments, the system also includes tongue sense circuitry for determining if a patient's tongue is in contact with the plurality of electrodes located on the bottom portion of the mouthpiece. In some embodiments, the system also includes a real time clock for determining a total time of usage of the mouthpiece. In some embodiments, the system also includes a battery for providing a current to the mouthpiece. In some embodiments, the system also includes an optical indicator that indicates a power level of the battery. In some embodiments, the system also includes an audio indicator that can warn the patient when the remaining battery charge is inadequate to complete a therapy session.
In yet another aspect, the invention features a system for providing non-invasive neuromodulation to a patient. The system includes a mouthpiece. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes control circuitry mounted within a top portion of the elongated housing for controlling electrical signals delivered to the electrodes. The system also includes a mobile device configured to send electrical control signals to the mouthpiece, the electrical control signals determining an amplitude and duration of electrical signals delivered to the patient's tongue.
In some embodiments, the system also includes an accelerometer for measuring an activity level of the patient. In some embodiments, the system also includes a data logger for logging information related to the activity level of the patient. In some embodiments, the system also includes tongue sense circuitry for determining if a patient's tongue is in contact with the plurality of electrodes located on the bottom portion of the mouthpiece. In some embodiments, the system also includes a real time clock for determining a total time of usage of the mouthpiece. In some embodiments, the system also includes an audio indicator that can warn the patient when the remaining battery charge is inadequate to complete a therapy session.
In yet another aspect, the invention features a controller for delivering electrical control signals to a mouthpiece during a non-invasive neuromodulation therapy session. The controller includes an elongated u-shaped element configured to rest upon a patient's shoulders. The controller also includes an electronic receptacle located at a terminus of the three-dimensional u-shaped element for connecting to a cable. The controller also includes a microcontroller located within the three-dimensional u-shaped element, the microprocessor configured to send electrical control signals to the mouthpiece, the electrical control signals determining an amplitude and duration of electrical signals delivered to the patient's tongue.
In some embodiments, the controller also includes an accelerometer for measuring an activity level of the patient and a data logger for logging information related to the activity level of the patient. In some embodiments, the controller also includes an audio alarm for indicating at least one of the end of a therapy session, a low electrical signal delivered to the patient's tongue, activation/deactivation of the controller, or pausing of the electrical signals delivered to the patient's tongue. In some embodiments, the controller also includes a power switch for activating and deactivating the controller and one or more intensity buttons for controlling the intensity of electrical signals delivered to the mouthpiece by the controller. In some embodiments, the controller also includes a display for presenting information and receiving input from the patient. In some embodiments, the controller also includes a battery for providing a current to the mouthpiece. In some embodiments, the controller also includes a motor for causing the u-shaped element to vibrate. In some embodiments, the controller also includes at least one printed circuit board for mounting electrical isolation circuitry, battery management circuitry, and a microcontroller, at least one printed circuit board for mounting a play button, a pause button, and the electronic receptacle, and at least one circuit board for mounting one or more intensity buttons. In some embodiments, the controller also includes circuitry for sensing a current delivered to a patient's tongue via the mouthpiece. In some embodiments, the controller also includes a cable forming an integral portion of the mouthpiece.
In yet another aspect, the invention features a controller for delivering electrical control signals to a mouthpiece during a non-invasive neuromodulation therapy session. The controller includes a coextensively dimensioned element configured to rest in proximity to a patient's face. The controller also includes a receptacle located at a central portion of a first surface of the coextensively dimensioned element, the receptacle providing an electrical and mechanical connection to the mouthpiece. The controller also includes a display located on a second surface of the coextensively dimensioned element, the display providing visual indications to the patient. The controller also includes a microcontroller located within the coextensively dimensioned element, the microcontroller configured to send electrical control signals to the mouthpiece, the electrical control signals determining an amplitude and duration of electrical signals delivered to the patient's tongue.
In some embodiments, the controller also includes an accelerometer for measuring an activity level of the patient and a data logger for logging the activity level of the patient, transmissions to or from the controller, the intensity of electrical signals delivered to the mouthpiece, and information received circuitry configured to determine if the patient's tongue is in contact with the mouthpiece. In some embodiments, the controller also includes an audio alarm for indicating at least one of the end of a therapy session, a low electrical signal delivered to the patient's tongue, activation/deactivation of the controller, or pausing of the electrical signals delivered to the patient's tongue. In some embodiments, the controller also includes a power switch for activating and deactivating the controller and one or more intensity buttons located on a third surface of the coextensively dimensioned element, the intensity buttons controlling the intensity of electrical signals delivered to the mouthpiece by the controller. In some embodiments, the controller also includes a display for presenting information and receiving input from the patient. In some embodiments, the controller also includes a battery for providing a current to the mouthpiece. In some embodiments, the controller also includes a motor for causing the coextensively dimensioned element to vibrate. In some embodiments, the controller also includes at least one printed circuit board for mounting electrical isolation circuitry, battery management circuitry, and a microcontroller, at least one printed circuit board for mounting a play button and a pause button, at least one printed circuit board for mounting the circuitry associated with the receptacle, and at least one circuit board for mounting one or more intensity buttons. In some embodiments, the controller also includes circuitry for sensing a current delivered to a patient's tongue via the mouthpiece.
In yet another aspect, the invention features a method for providing non-invasive neurorehabilitation of a patient. The method includes connecting a mouthpiece to a controller. The method also includes transmitting a numeric sequence generated by a first processor within the controller to the mouthpiece. The method also includes generating a first hash code by a second processor within the mouthpiece, the first hash code based on the received numeric sequence and a shared secret key stored in memory within the mouthpiece. The method also includes transmitting the first hash code from the mouthpiece to the controller. The method also includes generating a second hash code by the first processor within the controller, the second hash code based on the random number and the shared secret key. The method also includes comparing, by the first processor, the first hash code with the second hash code. The method also includes enabling electrical communication between the mouthpiece and the controller only if the first hash code matches the second hash code. The method also includes contacting the mouthpiece with the patient's intraoral cavity. The method also includes delivering neurostimulation to the patient's intraoral cavity, the neurostimulation being delivered by the controller via the mouthpiece.
In some embodiments, the method also includes connecting the mouthpiece to the controller via a cable. In some embodiments, the method also includes providing power to the controller. In some embodiments, the method also includes delivering electrical neurostimulation via an electrode array to the patient's intraoral cavity.
In yet another aspect, the invention features a method for providing non-invasive neurorehabilitation of a patient via a controller and a mouthpiece. The method includes connecting the mouthpiece to the controller. The method also includes generating a first hash code based on a unique serial number and a shared secret key. The method also includes storing the unique serial number and the first hash code in memory located in the mouthpiece. The method also includes transmitting the first hash code and the unique serial number from the mouthpiece to the controller. The method also includes generating a second hash code in a first processor in the controller, the second hash code based on the unique serial number and the shared secret key. The method also includes permitting electrical communication between the mouthpiece and the controller only if the first hash code matches the second hash code. The method also includes contacting the mouthpiece with the patient's intraoral cavity. The method also includes delivering neurostimulation to the patient's intraoral cavity, the neurostimulation being delivered by the controller via the mouthpiece.
In some embodiments, the method also includes connecting the mouthpiece to the controller via a cable. In some embodiments, the method also includes providing power to the controller. In some embodiments, the method also includes delivering electrical neurostimulation via an electrode array to the patient's intraoral cavity. In some embodiments, the first hash code is an SHA-256 hash code.
In yet another aspect, the invention features a mouthpiece for providing neurorehabilitation to a patient, the mouthpiece receiving electrical neurostimulation signals from a controller and selectively delivering the received electrical neurostimulation signals to the patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes control circuitry mounted within a top portion of the elongated housing for controlling electrical signals delivered to the electrodes. The mouthpiece also includes a memory mounted within a top portion of the elongated housing. The mouthpiece also includes a processor mounted within the top portion of the elongated housing, the processor configured to (i) receive a numeric sequence from the controller, (ii) generate a first hash code based on the received numeric sequence and a shared secret key stored in the memory, (iii) transmit the first hash code to the controller, (iv) receive communications from the controller only if a second hash code based on the numeric sequence and the shared secret key generated at the controller matches the first hash code.
In yet another aspect, the invention features a mouthpiece for providing neurorehabilitation to a patient, the mouthpiece receiving electrical neurostimulation signals from a controller and selectively delivering the received electrical neurostimulation signals to the patient. The mouthpiece includes an elongated housing having an anterior region and a posterior region, the elongated housing having a non-planar exterior top surface. The mouthpiece also includes a printed circuit board mounted to a bottom portion of the elongated housing, the printed circuit board having a plurality of electrodes for delivering subcutaneous local electrical stimulation to the patient's tongue. The mouthpiece also includes control circuitry mounted within a top portion of the elongated housing for controlling electrical signals delivered to the electrodes. The mouthpiece also includes a memory mounted within the top portion of the elongated housing. The mouthpiece also includes a processor mounted within the top portion of the elongated housing, the processor configured to (i) store a first hash code and a unique serial number, the first hash code based on the unique serial number and a shared secret key (ii) transmit the first hash code and the unique serial number to the controller, (iv) receive communications from the controller only if a second hash code based on the unique serial number and the shared secret key generated at the controller matches the first hash code. In some embodiments, the first hash code is an SHA-256 hash code.
As used herein, the terms “approximately,” “roughly,” and “substantially” mean±10%, and in some embodiments, ±5%. Reference throughout this specification to “one example,” “an example,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present technology. Thus, the occurrences of the phrases “in one example,” “in an example,” “one embodiment,” or “an embodiment” in various places throughout this specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, routines, steps, or characteristics may be combined in any suitable manner in one or more examples of the technology. The headings provided herein are for convenience only and are not intended to limit or interpret the scope or meaning of the claimed technology.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of the invention described above, together with further advantages, may be better understood by referring to the following description taken in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
FIG. 1 is a drawing of a patient engaged in a non-invasive neurostimulation therapy session according to an illustrative embodiment of the invention.
FIGS. 2A and 2B are diagrams showing a neurostimulation system according to an illustrative embodiment of the invention.
FIG. 2C is a diagram showing a neurostimulation system according to an illustrative embodiment of the invention.
FIG. 3A is a diagram showing a more detailed view of the neurostimulation system depicted in FIGS. 2A and 2B .
FIG. 3B is a diagram showing a more detailed view of the neurostimulation system depicted in FIG. 2C .
FIG. 3C is a diagram showing a more detailed view of an electrode array.
FIG. 3D is a graph showing an exemplary sequence of pulses for effecting neurostimulation of a patient.
FIG. 4A is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
FIG. 4B is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
FIG. 5A is a diagram showing a neurostimulation system according to an illustrative embodiment of the invention.
FIG. 5B is a diagram showing a controller according to an illustrative embodiment of the invention.
FIG. 5C is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
FIGS. 6A and 6B are diagrams showing a neurostimulation system according to an illustrative embodiment of the invention.
FIGS. 7A and 7B are diagrams showing a neurostimulation system according to an illustrative embodiment of the invention.
FIGS. 8A and 8B are diagrams showing a neurostimulation system according to an illustrative embodiment of the invention.
FIG. 9A is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
FIG. 9B is a flow chart illustrating a method in accordance with one embodiment for operating a neurostimulation system.
DETAILED DESCRIPTION
FIG. 1 shows a patient 101 undergoing non-invasive neuromodulation therapy (NINM) using a neurostimulation system 100 . During a therapy session, the neurostimulation system 100 non-invasively stimulates various nerves located within the patient's oral cavity, including at least one of the trigeminal and facial nerves. In combination with the NINM, the patient engages in an exercise or other activity specifically designed to assist in the neurorehabilitation of the patient. For example, the patient can perform a physical therapy routine (e.g., moving an affected limb, or walking on a treadmill) engage in a mental therapy (e.g., meditation or breathing exercises), or a cognitive exercise (e.g., computer assisted memory exercises) during the application of NINM. The combination of NINM with an appropriately chosen exercise or activity has been shown to be useful in treating a range of maladies including, for example, traumatic brain injury, stroke (TBI), multiple sclerosis (MS), balance, gait, vestibular disorders, visual deficiencies, tremor, headache, migraines, neuropathic pain, hearing loss, speech recognition, auditory problems, speech therapy, cerebral palsy, blood pressure, relaxation, and heart rate. For example, a useful non-invasive neuromodulation (NINM) therapy routine has been recently developed as described in U.S. Pat. No. 8,849,407, the entirety of which is incorporated herein by reference.
FIGS. 2A and 2B show a non-invasive neurostimulation system 100 . The non-invasive neurostimulation system 100 includes a controller 120 and a mouthpiece 140 . The controller 120 includes a receptacle 126 and pushbuttons 122 . The mouthpiece 140 includes an electrode array 142 and a cable 144 . The cable 144 connects to the receptacle 126 , providing an electrical connection between the mouthpiece 140 and the controller 120 . In some embodiments, the controller 120 includes a cable. In some embodiments, the mouthpiece 140 and the controller 120 are connected wirelessly (e.g., without the use of a cable). During operation, a patient activates the neurostimulation system 100 by actuating one of the pushbuttons 122 . In some embodiments, the neurostimulation system 100 periodically transmits electrical pulses to determine if the electrode array 142 is in contact with the patient's tongue and automatically activates based on the determination. After activation, the patient can start an NINM treatment session, stop the NINM treatment session, or pause the NINM treatment session by pressing one of the pushbuttons 122 . In some embodiments, the neurostimulation system 100 periodically transmits electrical pulses to determine if the electrode array 142 is in contact with the patient's tongue and automatically pauses the NINM treatment session based on the determination. During an NINM treatment session, the patient engages in an exercise or other activity designed to facilitate neurorehabilitation. For example, during an NINM treatment session, the patient can engage in a physical exercise, a mental exercise, or a cognitive exercise. In some embodiments, the controller 120 has pushbuttons on both arms. In some embodiments, a mobile device can be used in conjunction with the controller 120 and the mouthpiece 140 . The mobile device can include a software application that allows a user to activate the neurostimulation system 100 and start or stop an NINM treatment session by for example, pressing a button on the mobile device, or speaking a command into the mobile device. The mobile device can obtain patient information and treatment session information before, during, or after an NINM treatment session. In some embodiments, the controller 120 includes a secure cryptoprocessor that holds a secret key, to be described in more detail below in connection with FIGS. 9A and 9B . The secure cryptoprocessor is in communication with a microcontroller. The secure cryptoprocessor can be tamper proof. For example, if outer portions of the cryptoprocessor are removed in an attempt to access the secret key, the cryptoprocessor erases all memory, preventing unauthorized access of the secret key.
FIG. 2C shows a non-invasive neurostimulation system 100 . As shown, a mobile device 121 is in communication with a mouthpiece 140 . More specifically, the mobile device 121 includes a processor running a software application that facilitates communications with the mouthpiece 140 . The mobile device 121 can be, for example, a mobile phone, a portable digital assistant (PDA), or a laptop. The mobile device 121 can communicate with the mouthpiece 140 by a wireless or wired connection. During operation, a patient activates the neurostimulation system 100 via the mobile device 121 . After activation, the patient can start an NINM treatment session, stop the NINM treatment session, or pause the NINM treatment session by manipulating the mobile device 121 . During an NINM treatment session, the patient engages in an exercise or activity designed to provide neurorehabilitation. For example, during an NINM treatment session, the patient can engage in a physical exercise, a mental exercise, or a cognitive exercise.
FIG. 3A shows the internal circuitry housed within the controller 120 . The circuitry includes a microcontroller 360 , isolation circuitry 379 , a universal serial bus (USB) connection 380 , a battery management controller 382 , a battery 362 , a push-button interface 364 , a display 366 , a real time clock 368 , an accelerometer 370 , drive circuitry 372 , tongue sense circuitry 374 , audio feedback circuitry 376 , vibratory feedback circuitry 377 , and a non-volatile memory 378 . The drive circuitry 372 includes a multiplexor, and an array of resistors to control voltages delivered to the electrode array 142 . The microcontroller 360 is in electrical communication with each of the components shown in FIG. 3A . The isolation circuitry 379 provides electrical isolation between the USB connection 380 and all other components included in the controller 120 . Additionally, the circuitry shown in FIG. 3A is in communication with the mouthpiece 140 via the external cable 144 . During operation, the microcontroller 360 receives electrical power from battery 362 and can store and retrieve information from the non-volatile memory 378 . The battery can be charged via the USB connection 380 . The battery management circuitry controls the charging of the battery 362 . A patient can interact with the controller 120 via the push-button interface 122 that converts the patient's pressing of a button (e.g. an info button, a power button, an intensity-up button, an intensity-down button, and a start/stop button) into an electrical signal that is transmitted to the microcontroller 360 . For example, a therapy session can be started when the patient presses a start/stop button after powering on the controller 120 . During the therapy session, the drive circuitry 372 provides an electrical signal to the mouthpiece 140 via the cable 144 . The electrical signal is communicated to the patient's intraoral cavity via the electrode array 142 . The accelerometer 370 can be used to provide information about the patient's motion during the therapy session. Information provided by the accelerometer 370 can be stored in the non-volatile memory 378 at a coarse or detailed level. For example, a therapy session aggregate motion index can be stored based on the number of instances where acceleration rises above a predefined threshold, with or without low pass filtering. Alternatively, acceleration readings could be stored at a predefined sampling interval. The information provided by the accelerometer 370 can be used to determine if the patient is engaged in a physical activity. Based on the information received from the accelerometer 370 , the microcontroller 360 can determine an activity level of the patient during a therapy session. For example, if the patient engages in a physical activity for 30 minutes during a therapy session, the accelerometer 370 can periodically communicate (e.g. once every second) to the microcontroller 360 that the sensed motion is larger than a predetermined threshold (e.g. greater than 1 m/s 2 ). In some embodiments, the accelerometer data is stored in the non-volatile memory 378 during the therapy session and transmitted to the mobile device 121 after the therapy session has ended. After the therapy session has ended, the microcontroller 360 can record the amount of time during the therapy session in which the patient was active. In some embodiments, the recorded information can include other data about the therapy session (e.g., the date and time of the session start, the average intensity of electrical neurostimulation delivered to the patient during the session, the average activity level of the patient during the session, the total session time the mouthpiece has been in the patient's mouth, the total session pause time, the number of session shorting events, and/or the length of the session or the type of exercise or activity performed during the therapy session) and can be transmitted to a mobile device. A session shorting event can occur if the current transmitted from the drive circuitry to the electrode array 142 exceeds a predetermined threshold or if the charge transmitted from the drive circuitry to the electrode array exceeds a predetermined threshold over a predetermined time interval. After a session shorting event has occurred, the patient must manually press a pushbutton to resume the therapy session. The real time clock (RTC) 368 provides time and date information to the microcontroller 360 . In some embodiments, the controller 120 is authorized by a physician for a predetermined period of time (e.g., two weeks). The RTC 368 periodically communicates date and time information to the microcontroller 360 . In some embodiments, the RTC 368 is integrated with the microcontroller. In some embodiments, the RTC 368 is powered by the battery 362 , and upon failure of the battery 362 , the RTC 368 is powered by a backup battery. After the predetermined period of time has elapsed, the controller 120 can no longer initiate the delivery of electrical signals to the mouthpiece 140 and the patient must visit the physician to reauthorize use of the controller 120 . The display 366 displays information received by the microcontroller 360 to the patient. For example, the display 366 can display the time of day, therapy information, battery information, time remaining in a therapy session, error information, and the status of the controller 120 . The audio feedback circuitry 376 and vibratory feedback circuitry 377 can give feedback to a user when the device changes state. For example, when a therapy session begins, the audio feedback circuitry 376 and the vibratory feedback circuitry 377 can provide auditory and/or vibratory cues to the patient, notifying the patient that the therapy session has been initiated. Other possible state changes that may trigger audio and/or vibratory cues include pausing a therapy session, resuming a therapy session, the end of a timed session, canceling a timed session, or error messaging. In some embodiments, a clinician can turn off one or more of the auditory or vibratory cues to tailor the feedback to an individual patient's needs. The tongue sense circuitry 374 measures the current passing from the drive circuitry to the electrode array 142 . Upon sensing a current above a predetermined threshold, the tongue sense circuitry 374 presents a high digital signal to the microcontroller 360 , indicating that the tongue is in contact with the electrode array 142 . If the current is below the predetermined threshold, the tongue sense circuitry 374 presents a low digital signal to the microcontroller 360 , indicating that the tongue is not in contact or is in partial contact with the electrode array 142 . The indications received from the tongue sense circuitry 374 can be stored in the non-volatile memory 378 . In some embodiments, the display 366 can be an organic light emitting diode (OLED) display. In some embodiments, the display 366 can be a liquid crystal display (LCD). In some embodiments, a display 366 is not included with the controller 120 . In some embodiments, neither the controller 120 nor the mouthpiece 140 includes a cable, and the controller 120 communicates wirelessly with the mouthpiece 140 . In some embodiments, neither the controller 120 nor the mouthpiece 140 includes an accelerometer. In some embodiments, the drive circuitry 372 is located within the mouthpiece. In some embodiments, a portion of the drive circuitry 372 is located within the mouthpiece 140 and a portion of the drive circuitry 372 is located within the controller 120 . In some embodiments, neither the controller 120 nor the mouthpiece 140 includes tongue sense circuitry 374 . In some embodiments, the mouthpiece 140 includes a microcontroller and a multiplexer.
FIG. 3B shows a more detailed view of FIG. 2C . The mouthpiece 140 includes a battery 362 , tongue sense circuitry 374 , an accelerometer 370 , a microcontroller 360 , drive circuitry 372 , a non-volatile memory 378 , a universal serial bus controller (USB) 380 , and battery management circuitry 382 . During operation, the microcontroller receives electrical power from battery 362 and can store and retrieve information from the non-volatile memory 378 . The battery can be charged via the USB connection 380 . The battery management circuitry 382 controls the charging of the battery 362 . A patient can interact with the mouthpiece 140 via the mobile device 121 . The mobile device 121 includes an application (e.g. software running on a processor) that allows the patient to control the mouthpiece 140 . For example, the application can include an info button, a power button an intensity-up button, an intensity-down button, and a start/stop button that are presented to the user visually via the mobile device 121 . When the patient presses a button presented by the application running on the mobile device 121 , a signal is transmitted to the microcontroller 360 housed within the mouthpiece 140 . For example, a therapy session can be started when the patient presses a start/stop button on the mobile device 121 . During the therapy session, the drive circuitry 372 provides an electrical signal to an electrode array 142 located on the mouthpiece 140 . The accelerometer 370 can be used to provide information about the patient's motion during the therapy session. The information provided by the accelerometer 370 can be used to determine if the patient is engaged in a physical activity. Based on the information received from the accelerometer 370 , the microcontroller 360 can determine an activity level of the patient during a therapy session. For example, if the patient engages in a physical activity for 30 minutes during a therapy session, the accelerometer 370 can periodically communicate (e.g. once every second) to the microcontroller 360 that the sensed motion is larger than a predetermined threshold (e.g. greater than 1 m/s 2 ). After the therapy session has ended, the microcontroller 360 can record the amount of time during the therapy session in which the patient was active. In some embodiments, the accelerometer 370 is located within the mobile device 121 and the mobile device 121 determines an activity level of a patient during the therapy session based on information received from the accelerometer 370 . The mobile device can then record the amount of time during the therapy session in which the patient was active. The mobile device 121 includes a real time clock (RTC) 368 that provides time and date information to the microcontroller 360 . In some embodiments, the mouthpiece 140 is authorized by a physician for a predetermined period of time (e.g., two weeks). After the predetermined period of time has elapsed, the mouthpiece 140 can no longer deliver electrical signals to the patient via the electrode array 142 and the patient must visit the physician to reauthorize use of the mouthpiece 140 . In some embodiments, the mouthpiece 140 includes pushbuttons (e.g., an on/off button) and a patient can manually operate the mouthpiece 140 via the pushbuttons. After a therapy session, the mouthpiece 140 can transmit information about the therapy session to a mobile device. In some embodiments, the mouthpiece 140 does not include a USB controller 380 and instead communicates only via wireless communications with the controller.
FIG. 3C shows a more detailed view of the electrode array 142 . The electrode array 142 can be separated into 9 groups of electrodes, labelled a-i, with each group having 16 electrodes, except group b which has 15 electrodes. Each electrode within the group corresponds to one of 16 electrical channels. During operation, the drive circuitry can deliver a sequence of electrical pulses to the electrode array 142 to provide neurostimulation of at least one of the patient's trigeminal or facial nerve. The electrical pulse amplitude delivered to each group of electrodes can be larger near a posterior portion of the tongue and smaller at an anterior portion of the tongue. For example, the pulse amplitude of electrical signals delivered to groups a-c can be 19 volts or 100% of a maximum value, the pulse amplitude of electrical signals delivered to groups d-f can be 14.25 volts or 75% of the maximum value, the pulse amplitude of electrical signals delivered to groups g-h can be 11.4 volts or 60% of the maximum value, and the pulse amplitude of electrical signals delivered to group i can be 9.025 volts or 47.5% of the maximum value. In some embodiments, the maximum voltage is in the range of 0 to 40 volts. The pulses delivered to the patient by the electrode array 142 can be random or repeating. The location of pulses can be varied across the electrode array 142 such that different electrodes are active at different times, and the duration and/or intensity of pulses may vary from electrode. For oral tissue stimulation, currents of 0.5-50 mA and voltages of 1-40 volts can be used. In some embodiments, transient currents can be larger than 50 mA. The stimulus waveform may have a variety of time-dependent forms, and for cutaneous electrical stimulation, pulse trains and bursts of pulses can be used. Where continuously supplied, pulses may be 1-500 microseconds long and repeat at rates from 1-1000 pulses/second. Where supplied in bursts, pulses may be grouped into bursts of 1-100 pulses/burst, with a burst rate of 1-100 bursts/second.
In some embodiments, pulsed waveforms are delivered to the electrode array 142 . FIG. 3D shows an exemplary sequence of pulses that can be delivered to the electrode array 142 by the drive circuitry 372 . A burst of three pulses, each spaced apart by 5 ms is delivered to each of the 16 channels. The pulses in neighboring channels are offset from one another by 312.5 μs. The burst of pulses repeats every 20 ms. The width of each pulse can be varied from 0.3-60 μs to control an intensity of neurostimulation (e.g., a pulse having a width of 0.3 μs will cause a smaller amount of neurostimulation than a pulse having a width of 60 μs).
FIG. 4A shows a method of operation 400 of a controller 120 as described in FIGS. 2A, 2B and 3A . A patient attaches a mouthpiece 140 to a controller 120 (step 404 ). The patient turns on the controller 120 (step 408 ) using, for example, a power button. The patient places the controller 120 around his/her neck (step 412 ) as shown in FIG. 1B . The patient places a mouthpiece 140 in his/her mouth (step 416 ). The patient initiates a therapy session by pressing a start/stop button (step 420 ). During the therapy session, the controller 120 delivers electrical signals to the mouthpiece 140 . The patient calibrates the intensity of the electrical signals (step 424 ). The patient raises the intensity of the electrical signals delivered to the mouthpiece by pressing an intensity-up button until the neurostimulation is above the patient's sensitivity level. The patient presses an intensity-down button until the neurostimulation is comfortable and non-painful. After the calibration step, the patient performs a prescribed exercise (step 428 ). The exercise can be cognitive, mental, or physical. In some embodiments, physical exercise includes the patient attempting to maintain a normal posture or gait, the patient moving his/her limbs, or the patient undergoing speech exercises. Cognitive exercises can include “brain training” exercises, typically computerized, that are designed to require the use of attention span, memory, or reading comprehension. Mental exercises can include visualization exercises, meditation, relaxation techniques, and progressive exposure to “triggers” for compulsive behaviors.
In some embodiments, the patient can rest for a period of time during the therapy session (e.g. the patient can rest for 2 minutes during a 30 minute therapy session). After a predetermined period of time (for example, thirty minutes) has elapsed, the therapy session ends (step 432 ) and the controller 120 stops delivering electrical signals to the mouthpiece 140 . In some embodiments, the intensity of electrical signals increases from zero to the last use level selected by the patient over a time duration in the range of 1-5 seconds after the patient starts a therapy session by pressing the start/stop button. In some embodiments, the intensity of electrical signals is set to a fraction of the last use level selected by the patient (e.g. ¾ of the last level selected) after the patient starts a therapy session by pressing the start/stop button. In some embodiments, the intensity of electrical signals increases from zero to a fraction of the last use level selected by the patient (e.g. ¾ of the last level selected) over a time duration in the range of 1-5 seconds after the patient starts a therapy session by pressing the start/stop button. In some embodiments, the intensity of electrical signals increases instantaneously from zero to the last use level selected by the patient after the patient starts a therapy session by pressing the start/stop button.
In some embodiments, the mouthpiece 140 is connected to the controller 120 after the controller 120 is turned on. In some embodiments, the mouthpiece 140 is connected to the controller 120 after the controller 120 is donned by the patient. In some embodiments, the patient calibrates the intensity of the electrical signals before initiating a therapy session. In some embodiments, a patient performs an initial calibration of the intensity of electrical signals in the presence of a clinician and does not calibrate the intensity of the electrical signals during subsequent treatments performed in the absence of a clinician.
FIG. 4B shows a method of operation 449 of the non-invasive neurostimulation system 100 described in FIGS. 2C and 3B . A patient activates a mobile device 121 (step 450 ). The patient places a mouthpiece 140 in his/her mouth (step 454 ). The patient initiates a therapy session by pressing a start/stop button within an application running on the mobile device 121 (step 458 ). During the therapy session, circuitry within the mouthpiece 140 delivers electrical signals to an electrode array 142 located on the mouthpiece 140 . The patient calibrates the intensity of the electrical signals (step 462 ). The patient first raises the intensity of the electrical signals delivered to the mouthpiece 140 by pressing an intensity-up button located within an application running on the mobile device 121 until the neurostimulation is above the patient's sensitivity level. The patient presses an intensity-down button running within an application on the mobile device 121 until the neurostimulation is comfortable and non-painful. After the calibration step, the patient performs a prescribed exercise (step 464 ). The exercise can be cognitive, mental, or physical. In some embodiments, the patient can rest for a period of time during the therapy session (e.g. the patient can rest for 5 minutes during a 30 minute therapy session). After a predetermined period of time (for example, thirty minutes) has elapsed, the therapy session ends (step 468 ) and the circuitry located within the mouthpiece 140 stops delivering electrical signals to the electrode array 142 . In some embodiments, the calibration of the intensity of the electrical signals takes place before the patient initiates a therapy session.
FIG. 5A shows a neurostimulation system 500 and FIG. 5B shows a back view of a controller 520 . The neurostimulation system 500 includes a controller 520 and a mouthpiece 540 connected via a cable 544 . The mouthpiece 540 includes an electrode array on a bottom portion thereof. The controller 520 includes an anterior portion 560 and a posterior portion 564 . The controller 520 also includes a mouthpiece port 516 , an intensity-up button 508 , an intensity-down button 512 , a power button 521 , an info button 524 , a start/stop button 504 and a display 528 . The mouthpiece 540 is in electrical communication with the controller 520 via the cable 544 . In some embodiments, the power button 521 includes a light emitting diode (LED) indicator. In some embodiments, the port 516 is located on the mouthpiece 540 instead of the controller 520 and the cable 544 is permanently attached to the controller 520 . In some embodiments the port is a universal serial bus (USB) port and/or a charging port.
FIG. 5C describes a method 200 of operating the neurostimulation system 500 shown in FIGS. 5A and 5B . A patient activates the neurostimulation system 500 by pressing a power button 521 (step 208 ). After activation, the neurostimulation system 500 enters an idle state (step 212 ). While in the idle state, non-invasive neurostimulation is not delivered to the patient. If the neurostimulation system 500 remains in the idle state for a predetermined time period, the neurostimulation system 500 can shut down or enter a power-saving state (e.g., after idling for 10 minutes). Additionally, if the power button 521 is pressed while in the idle state, the neurostimulation system 500 shuts down. If the patient presses a start button (step 224 ), an NINM therapy session begins and non-invasive neurostimulation generated by the controller 520 is delivered to the patient's oral cavity via the mouthpiece 540 for a predetermined period of time. In some embodiments, the neurostimulation system 500 enters an intensity adjustment state when the patient presses a start button (step 224 ). The patient then raises the intensity of the electrical signals delivered to the mouthpiece by pressing the intensity-up button 508 until the neurostimulation is above the patient's sensitivity level. The patient presses the intensity-down button 512 until the neurostimulation is comfortable and non-painful. After the intensity adjustment is completed, the patient presses the start button again to begin an NINM therapy session. In one embodiment, the predetermined period of time can be in the user-selectable range of 20-30 minutes. Additionally, the patient performs a physical, cognitive, or mental exercise during the NINM therapy session. The physical, cognitive, or mental exercise is performed simultaneously with the delivery of electrical signals from the controller 520 to the mouthpiece 540 . If the patient presses a pause button (step 232 ) while neurostimulation is being delivered, the therapy session is paused (step 233 ) and the neurostimulation system 500 ceases to deliver non-invasive neurostimulation to the patient's oral cavity. In some embodiments, if the neurostimulation system 500 loses contact with the patient's oral cavity (e.g. determined by tongue sensing circuitry), the therapy session is paused. If the patient presses unpause (step 234 ), the treatment is resumed and non-invasive neurostimulation is again delivered to the patient's intraoral cavity. If the patient presses the stop button while the neurostimulation system 500 is paused, or if there is no patient input for more than a predetermined time, for example, two minutes (step 235 ) after the patient has pressed the pause button, the neurostimulation system 500 enters an idle state (step 212 ) and a “treatment ended due to pause timeout” message is presented by the display 528 . If the patient presses the stop button (step 240 ) while neurostimulation is being delivered, the neurostimulation system 500 enters an idle state (step 212 ) and a “treatment ended due to session stop” message is presented by the display 528 . Alternatively, if the neurostimulation system 500 delivers neurostimulation to the patient for the full predetermined period of time at step 240 , the system enters an idle state at step 212 and a “full session completed” message is presented by the display 528 .
While the system is in the idle state at step 212 , a number of conditions can prevent the patient from initiating a therapy session. For example, if there is not enough charge remaining in the battery to complete at least one NINM therapy session, the controller 520 can block the patient from initiating the therapy session and a “low battery” message will be presented on the display 528 . In some embodiments, the controller can emit an audible sound to alert the patient that there is not enough charge remaining in the battery to complete at least one NINM therapy session. Additionally, if the mouthpiece 540 is not attached to the controller 520 , the controller 520 can block the patient from initiating a therapy session and a “no mouthpiece” message is presented on the display 528 .
In some embodiments, the neurostimulation system 500 delivers neurostimulation for a limited number of hours per day. For example, the neurostimulation system 500 can be configured to stop delivering neurostimulation after 200 minutes of use in a single day. In the idle state at step 212 , if the daily limit has been exceeded, the controller 520 can block the patient from initiating a therapy session and a “daily limit reached” message is presented by the display 528 . The patient can begin treatment the next day (i.e., after midnight), when the daily limit is reset.
In some embodiments, the neurostimulation system 500 delivers neurostimulation for a limited number of weeks. In the idle state at step 212 , if the calendar limit has been exceeded, the controller 520 can block the patient from initiating a therapy session and a “calendar limit reached” message is presented by the display 528 . For example, the neurostimulation system 500 can be configured to stop delivering neurostimulation 1-14 weeks after the patient receives the neurostimulation system 500 from a physician. To re-enable the neurostimulation system 500 after the calendar limit has been exceeded, the patient is required to visit a physician or a clinician. In some embodiments, a “calendar limit approaching” message is presented by the display 528 , warning the patient that the calendar limit will be reached soon (e.g. in two weeks). The “calendar limit approaching” message can be beneficial to patients by allowing them to schedule appointments with their clinicians prior to the calendar limit being reached.
In some embodiments, the mouthpiece 540 can become damaged over time and require replacement. For example, the patient's bites down on the mouthpiece 540 during each therapy session, slowly causing the surface of the mouthpiece to be damaged. This damage can cause the mouthpiece 540 to malfunction. The average time to failure can be statistically determined by testing a number of mouthpieces 540 over a number of therapy sessions and examining the mouthpieces for damage at the end of each therapy session. The average time to failure, once determined, can be programmed into the controller 520 . During the idle state at step 212 , if the average time to failure has been reached, the controller 520 can block the patient from initiating a therapy session and a “mouthpiece expired” message is presented by the display 528 . In some embodiments, a message is presented by the display 528 , warning the patient that the mouthpiece is set to expire soon. For example, the message presented by the display 528 can be “mouthpiece expires in 14 days.”
In some embodiments, the display 528 can present an “authentication error” message if a mouthpiece 540 cannot be authenticated, for example as described in FIGS. 9A and 9B . In some embodiments, the neurostimulation system 500 tracks an activity level of a patient. For example, the neurostimulation system 500 can include an accelerometer that detects an activity level of the patient (e.g., at rest, walking, or running) In some embodiments, the activity level can be recorded and stored on an external computer for analysis. For example, the recorded activity level data can be analyzed by a physician to determine an effectiveness of a prescribed treatment plan. In some embodiments, the neurostimulation system 500 sets an intensity level to 75% of the last used intensity level when the treatment begins at step 228 . In some embodiments, data including time stamps, intensity levels, data received from the accelerometer, and data received from the tongue sense circuitry can be recorded and stored on an external computer or mobile device for analysis.
In some embodiments, the port 516 can facilitate charging of the neurostimulation system 500 . For example, when the port 516 is connected to a charging source, the neurostimulation system 500 enters a charging state. In the charging state, a “Charging” message is presented by the display 528 . Additionally, in the charging state, an LED can indicate a remaining battery charge. For example, the LED can emit flashing red light if there is not sufficient battery charge for at least one NINM therapy session. If there is sufficient battery charge remaining to complete at least one NINM therapy session, the LED can emit flashing green. When the battery charging is complete, the LED can emit a solid green light (e.g. a non-flashing green light). While the neurostimulation system 500 is in the charging state, the patient cannot begin an NINM therapy session. When the port is disconnected in the charging state, the neurostimulation system 500 enters an idle state (step 212 ).
In some embodiments, an LED included with the power button 521 can indicate a remaining battery charge. For example, the LED can emit green light if there is sufficient battery charge remaining to complete two or more NINM therapy sessions. If there is sufficient battery charge remaining to complete one NINM therapy session, the LED can emit yellow light. If there is not enough charge remaining for one NINM therapy session, the LED can emit red light. In some embodiments, the controller 520 includes LEDs for providing visual indication, an audio indicator, or a vibratory indicator that can provide indications to the patient. For example, the LEDs, the audio indicator, and the vibratory indicator can provide an indication to the patient if electrical neurostimulation is being delivered to the mouthpiece 540 , if electrical neurostimulation delivery to the mouthpiece 540 has been disabled or cancelled, or if the NINM therapy session has ended. The indications can include a solid or flashing light emitted by the LEDs or a predetermined sound such as a ring, buzz, or chirp emitted by the audio indicator. The vibratory indicator can provide tactile feedback or other vibratory feedback to the patient. In some embodiments, the audio and/or vibratory indicator includes a piezoelectric element or a magnetic buzzer that vibrates and provides a mechanical indication to the patient. In some embodiments, the LEDs and/or the audio indicator provide an indication when an NINM therapy session is 50% complete. In some embodiments, the LEDs and/or the audio indicator provide an indication when any button on the controller 520 is pressed by the patient. In some embodiments, the LEDs and/or the audio indicator provide an indication of the intensity level of the electrical neurostimulation. In some embodiments, the LEDs and/or the audio indicator provide an indication of the remaining NINM therapy session time. In some embodiments, the LEDs and/or the audio indicator provide an indication of the remaining stimulation minutes for the current day (e.g., before a daily limit is reached). In some embodiments, the LEDs and/or the audio indicator provide an indication of the remaining stimulation minutes for the current calendar period (e.g., before a calendar limit is reached). In some embodiments, pressing a start/stop/pause button while neurostimulation is being delivered pauses the therapy session (step 233 ) and the neurostimulation system 500 ceases to deliver non-invasive neurostimulation to the patient's oral cavity.
FIGS. 6A and 6B show a non-invasive neurostimulation system 600 . The non-invasive neurostimulation system 600 includes headband 618 , a controller 620 , pushbuttons 622 , a display 628 , a mouthpiece 640 , an electrode array 642 , and a cable 624 . The controller 620 is in electrical communication with the mouthpiece 640 and the electrode array 642 via the cable 624 . During operation, a patient rests the headband 618 along his/her ears and inserts the mouthpiece 640 into his/her mouth. Operation of the non-invasive neurostimulation system 600 is similar to that described above in reference to FIGS. 5A and 5B where similarly referenced elements have the same functionality (e.g. controller 620 has the same functionality as controller 520 etc.). In some embodiments, the headband 618 maintains an orientation of the mouthpiece 640 within the patient's mouth during an NINM therapy session. In some embodiments, the headband 618 maintains the position of the mouthpiece 640 within the patient's mouth, even if the patient is in a horizontal orientation or is upside-down.
FIGS. 7A and 7B show a non-invasive neurostimulation system 700 . The non-invasive neurostimulation system 700 includes headband 718 , a controller 720 , an intensity setting wheel 722 , a mouthpiece 740 , an electrode array 742 , and a cable 724 . The controller 720 is in electrical communication with the mouthpiece 740 and the electrode array 742 via the cable 724 . During operation, a patient rests the headband 718 along an upper circumference of his/her head and inserts the mouthpiece 740 into his/her mouth. The patient can increase the intensity of the electrical signals delivered to the mouthpiece 740 by rotating the intensity setting wheel in a clockwise direction. The patient can decrease the intensity of the electrical signals delivered to the mouthpiece 740 by rotating the intensity setting wheel in a counterclockwise direction. Operation of the non-invasive neurostimulation system 700 is otherwise similar to that described above in reference to FIGS. 5A and 5B where similarly referenced elements have the same functionality (e.g. controller 720 has the same functionality as controller 520 etc.). In some embodiments, the headband 718 is configured to allow the patient to wear his/her glasses during an NINM therapy session.
FIGS. 8A and 8B show a non-invasive neurostimulation system 800 . The non-invasive neurostimulation system 800 includes a controller 820 , a mouthpiece 840 , pushbuttons 822 , display screen 828 , and indicator light 832 . The controller 820 and the mouthpiece 840 are integrated into a monolithic package. The controller 820 is in electrical communication with the mouthpiece 840 and the electrode array 842 . During operation, a patient inserts the mouthpiece 840 into his/her mouth and the rigidly attached controller 820 rests just outside of the patient's mouth. Operation of the non-invasive neurostimulation system 800 is otherwise similar to that described above in reference to FIGS. 5A and 5B where similarly referenced elements have the same functionality (e.g. controller 820 has the same functionality as controller 520 etc.). In some embodiments, the controller 820 is in mechanical contact with the patient's chin and is configured to mechanically secure the mouthpiece 840 during an NINM therapy session. In some embodiments, a display screen 828 is not included with non-invasive neurostimulation system 800 . In some embodiments, a display screen 828 is replaced with an auditory indicator that provides auditory messages to the patient. In some embodiments, the controller 820 and the mouthpiece 840 are each monolithic and connected at a connection point between the mouthpiece 840 and the controller 820 . In some embodiments, the mouthpiece 840 is removably attached to the controller 820 and can be replaced at predetermined usage intervals or upon wearing out.
FIG. 9A shows a method of operation 900 of the non-invasive neurostimulation device illustrated in FIGS. 5-8 . Initially a patient connects a mouthpiece to a controller or mobile device (step 904 ). The connection can be a wired or wireless connection. A processor within the controller or mobile device generates a numeric sequence and transmits the generated sequence to the mouthpiece (step 908 ). The numeric sequence generated at step 908 can be a sequence of random values, produced by a software pseudorandom number generator, or by a hardware random number generator. Based on the received numeric sequence and a secret key shared between the mouthpiece and the controller, a processor located within the mouthpiece generates a first hash code (step 912 ). The first hash code can be generated using an HMAC (keyed-hash message authentication code) algorithm. In some embodiments, the first hash code is generated in accordance with an SHA-256 algorithm. The mouthpiece then transmits the first hashcode to the controller (step 916 ). A processor located within the controller generates a second hash code based on the shared secret key and the numeric sequence (step 920 ) and then compares the first hash code with the second hash code (step 924 ). The numeric sequence generated at step 920 can be a sequence of random values, produced by a software pseudorandom number generator, or by a hardware random number generator. In some embodiments, the second hash code is generated in accordance with an SHA-256 algorithm. If the first hash code matches the second hash code, then electrical communications are enabled between the controller and the mouthpiece (step 928 ). The patient then inserts the mouthpiece into his/her mouth bringing the mouthpiece into contact with the patient's intraoral cavity (step 932 ). Electrical neurostimulation signals can then be delivered by the controller via the mouthpiece to the patient's intraoral cavity (step 936 ).
FIG. 9B shows another method of operation 939 of the non-invasive neurostimulation device as shown in FIGS. 5-8 in accordance with an embodiment of the invention. Initially, a patient connects a mouthpiece to a controller or mobile device (step 940 ). The connection can be a wired or wireless connection. At the time of manufacture, a first hash code is generated based on a unique serial number and a secret key shared between the mouthpiece and the controller (step 944 ). The first hash code can be generated by an HMAC (keyed-hash message authentication code) algorithm. In some embodiments, the first hash code is generated in accordance with an SHA-256 algorithm. The first hash code and the unique serial number are stored in memory within the mouthpiece. The mouthpiece then transmits the first hash code and the unique serial number to the controller (step 948 ). The controller generates a second hash code based on the received unique serial number and the shared secret key (step 952 ). The second hash code can be generated by an HMAC (keyed-hash message authentication code) algorithm. In some embodiments, the second hash code is generated in accordance with an SHA-256 algorithm. The controller then compares the second hash code and the first hash code. The controller only permits continued electrical communications with the mouthpiece if the second hash code and the first hash code match (step 956 ). The patient then inserts the mouthpiece into his/her mouth bringing the mouthpiece into contact with the patient's intraoral cavity (step 960 ). Electrical neurostimulation signals can then be delivered by the controller via the mouthpiece to the patient's intraoral cavity (step 964 ).
The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the inventive concepts. It will be understood that, although the terms first, second, third etc. are used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.
While the present inventive concepts have been particularly shown and described above with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art, that various changes in form and detail can be made without departing from the spirit and scope of the present inventive concepts described and defined by the following claims.
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A system for providing non-invasive neuromodulation to a patient includes a mouthpiece and a controller. The mouthpiece includes an elongated housing, a printed circuit board, control circuitry mounted within the elongated housing, and a cable for connecting to a controller. The controller includes an elongated u-shaped element, an electronic receptacle, and a microcontroller. A method for providing non-invasive neurorehabilitation of a patient including connecting a mouthpiece to a controller, transmitting a numeric sequence to the mouthpiece, generating a first hash code, transmitting the first hash code to the controller, generating a second hash code, comparing the second hash code with the first hash code, enabling electrical communication between the mouthpiece and the controller only if the first hash code matches the second hash code, contacting the mouthpiece with the patient's intraoral cavity, and delivering neurostimulation to the patient's intraoral cavity.
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FIELD OF THE INVENTION
This invention relates to helical screw type compressors with axial fluid flow in which means is provided for sensing the internal discharge pressure at the discharge end of the rotors and for controlling the size of the discharge opening so that full compression is substantially equal to the pressure of the area to which the fluid is discharged.
DESCRIPTION OF THE PRIOR ART
Axial flow helical screw type compressors are well known in the art. The desirability of substantially equalizing the pressure of fluid being discharged with that of the fluid in the discharge area has been recognized and structure provided for heretofore as in Lysholm U.S. Pat. No. 2,519,913 and Whitfield 3,151,806. More recently, Shaw U.S. Pat. No. Re. 29,283 has a generally similar objective.
The use of axially shiftable slide valves for adjusting the capacity of a screw compressor is disclosed in Schibbye U.S. Pat. No. 3,314,597 and Kocher et al U.S. Pat. No. 3,527,548.
Means for controlling the operation of the slide valve in response to suction or discharge pressure is found in various ones of the above patents.
The patent to Sprankle U.S. Pat. No. 3,977,818 discloses a helical screw type expander having a transversely movable valve member in the high pressure inlet wall for throttling water under high heat and pressure from geothermal streams.
SUMMARY OF THE INVENTION
The present invention is directed to a valve member and control means for controlling the size of the discharge opening in a helical screw type compressor with axial fluid flow in which the high pressure discharge opening is formed in the high pressure end wall and in which control means for the valve member is responsive to pressure at the internal face of the end wall in order to provide variable optimum control of the valve member. The position and shape of the transverse valve member is such as to permit the compressor to incorporate the customary axially movable slide valve member for capacity control which may be operated by means known in the art.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a horizontal sectional view through a screw type compressor in accordance with the present invention with portions broken away for clarity.
FIG. 2 is a sectional view taken on the line 2--2 of FIG. 1 and showing the high pressure end of the compressor.
FIG. 3 is a sectional view taken on the line 3--3 of FIG. 2.
FIG. 4 is an enlarged fragmentary sectional view taken on the line 4--4 of FIG. 1 with portions broken away to show the rotors.
FIG. 5 is a schematic view of the mechanism for controlling the transversely movable valve member.
FIG. 6 is a schematic view of the pipe connections for controlling the transverse valve member.
FIG. 7 is a schematic view of the electrical circuitry for controlling the transversely movable valve member.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With further reference to the drawings, a compressor 10 in accordance with the present invention has outer wall structure 11 shaped to house a pair of intermeshing helical rotors or screws 12 and 13 which are mounted for rotation in bearing means mounted in low pressure end wall 15 and high pressure end wall 16, respectively. Rotor 12 is carried in bearing means 17 and 18 and rotor 13 in bearing means 19 and 20 in the respective end walls. An inlet passageway (not shown) is located at one end of the compressor adjacent to the low pressure end wall 15.
The compressor has a capacity control valve slide member 22, the upper portion of which is shaped in a conventional manner to form a portion of the wall at the bottom inner section of the rotors. The valve slide member 22 is shiftable from a closed position in which it closes the space beneath the rotors for at least a portion of the length thereof to an open position in which one end of the slide member extends forwardly beyond the high pressure end wall 16, thereby providing an opening at the opposite end which permits fluid between the threads of the rotors to return to the inlet passageway area before it has been compressed. Such capacity control, itself, is already known in the art and is particularly useful for providing an unloaded condition when the compressor is started. Operation of the slide can be accomplished by means well known in the art such as sensing the suction pressure and using the high pressure oil from the lubrication pump to cause the slide member to move toward open position at low suction pressure and toward closed position at high suction pressure. Such controls are illustrated in Wagneius U.S. Pat. Nos. 3,045,447 and Schibbye 3,314,597.
In order to control the pressure of the fluid being discharged at the high pressure end wall 16, such end wall is provided with a slide valve member 25 which is movable in a direction normal to the axes of the rotors and is slidably mounted in an opening 26 in the end wall 16. The slide valve member 25 has parallel sides 27 and 28 which are received in the opening 26 and has inset guide ways 29 and 30 which receive guide members 31 and 32 that are mounted by suitable fasteners 33 on the outer face of the end wall 16. As illustrated in FIGS. 1 and 3, the plane of the axes of the rotors 12 and 13 is horizontal and the inner face of the slide valve member 25 is mounted substantially co-planar with the inside face of the high pressure end wall 16 for movement in a vertical plane transverse to the horizontal plane of the axes of the rotors.
The lower end of the valve member 25 is substantially inverted V-shaped to provide inclined surfaces 35, 36 which in the lowermost position of the member 25 is spaced from and generally complementary to the upper surfaces of the horizontal slide member 22, the spacing therebetween in the lowermost position of the valve member 25 providing a discharge opening 38 of a predetermined minimum. In an upper position as indicated in FIG. 4, the opening 38 is a predetermined maximum.
With particular reference to FIGS. 2 and 3, the valve member 25 is attached to a connecting rod 40 which connects it to an operating piston 41 which is vertically movable within cylinder 42 and having head 44. The position of the valve member 25 is controlled automatically by controlling the position of the piston 41 as will be described.
In order to control the position of the piston 41 and hence the position of the slide valve member 25 in response to the discharging pressures of the fluid, the slide valve member 25 is provided with passageways 50, 51, 52 with the passageway 52 being connected to a conduit 53 leading to a differential pressure control monitoring system which will be described. The passageways 50, 51 communicate directly with the inner face of the valve member 25 and are in axial alignment with the fluid being compressed by the rotors 12 and 13.
The upper portion of the high pressure end wall 16 has a bore 54 through which the piston rod 40 extends. A discharge cover 55 is attached to the end wall 16 in any desired manner and such discharge cover has a discharge passageway 56 for fluid discharged from the compressor. The discharge cover 55 has a conduit 57 which communicates the discharge passageway 56 with the differential control monitoring system.
Reference is now made to FIGS. 5, 6 and 7 for the details of the differential pressure control monitoring system. The system illustrated includes a rigid support member 60 having mounted thereon bellows 61 and 62, each being rigidly fixed to respective side walls 63 and 64 of the support member 60. The bellows are mounted opposite each other so as their free ends 65 and 66, respectively, may move toward and away from each other.
A pendulum 70 is rotatably mounted on a fixed pivot pin 71 carried by the support member 60. A pair of opposed adjustable engaging means 72 and 73 are mounted on the pendulum 70 substantially in alignment with the free ends 65 and 66 of the bellows and are positioned for close spacing (e.g., 0.001 inch to 0.003 inch) therefrom when the pendulum is in its central position. Another pair of adjustable engaging means 77 and 78 are mounted on the pendulum adjacent to the bottom end and are similarly positioned closely adjacent to the external operating points of a pair of microswitches 80 and 81 mounted on the support member 60. The microswitches are in normal open circuit position when the pendulum is in its central position.
Adjustable stops 82 and 84 are mounted at the top portion of the support member 60 and substantially in alignment with the upper end of the pendulum in order to limit the pendulum movement and thus prevent damage to the microswitches 80 and 81.
The control mechanism described is for the purpose of controlling the operating member for the piston 41, thereby controlling the position of the slide valve member 25. While various types of operating members might be employed, a preferred embodiment includes the use of the oil pump that is normally associated with a helical rotary compressor for the purpose of rotor sealing, lubrication and cooling, as well as providing the mode of power for the hydraulic operation of the capacity modulation slide valve 22, as is known in the art and described, e.g., in American Society of Heating, Refrigeration and Airconditioning Engineers, Inc. Handbook and Product Directory, 1979 Equipment, Chapter 12, pp 12.14-12.17. In FIG. 6, the oil pump is represented schematically and indicated by numeral 86 and has a discharge line 87 and return line 88. Discharge line 87 is connected at junction 89 to line 90, having solenoid valve 91 therein, to the head 44 for communication with the space above piston 41. Similarly, line 87 is connected via junction 89 to line 92, having solenoid valve 93 therein, to the space beneath the piston 41.
Return line 88 is connected by a junction 95 with line 96, having a solenoid valve 97, therein and connected to the line 90 for communication with the space above the piston head 41. Similarly, line 88 is connected by the junction 95 to line 98, having a solenoid valve 99 therein, for connection to the line 92 and communication with the space beneath the piston head 41.
A schematic of the electrical hookup appears in FIG. 7. Switch 100 is closed when the oil pump 86 builds up to a preliminary minimum operating pressure. A timing relay 101 is in the compressor starting circuit (not shown) and has a contact in parallel with the microswitch 80 and in series with the solenoid valves 93 and 97, thereby holding the discharge port control valve 25 fully open during compressor startup. Microswitch 81 is in series with solenoids 91 and 99 and in order to pressurize the top area of the cylinder head.
In the operation of the control system, after the compressor is started and the timing relay 101 is open, pressure at the discharge end of the compressor is sensed at the passageways 50, 51 and 52 and is transmitted by the conduit 53 through conventional oil separators 53' to the bellows 61. Simultantously, pressure from the discharge passageway 56 is transmitted by conduit 57 through an oil separator 57' to the bellows 62. If the pressure that is transmitted by conduit 53 is above that transmitted by conduit 57, this causes switch 80 and the circuits to the solenoids 93 and 97 to be closed, thereby energizing the corresponding valves and causing these to open and permit oil under pressure to enter the housing 42 under the piston 41 and permit oil relief above the piston 41, thereby causing the slide 25 to move upwardly and increase the discharge port opening 38.
When the pressure as sensed in the conduit 53 is lower than that sensed in conduit 57, this reverses the operation and causes closing of the circuit through microswitch 81 and solenoid valves 91 and 99, thereby applying increased pressure to the top of the piston 41 and relieving the pressure therebeneath, thus causing the valve member 25 to move downwardly and thereby reduce the size of the discharge opening 38.
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The high pressure end wall of an axial flow helical screw type compressor has a slide member which is movable transversely of the rotors for controlling the size of the discharge passage through the end wall and is controlled by sensing means responsive to the pressure at the end wall and in the discharge area in order that full compression which is substantially equal to the pressure at discharge may be obtained.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical transmitter module suitable for use in optical fiber communications and equipped with an electricabsorption type optical modulator for converting an electric signal to a light signal, and particularly to a circuit configuration of an optical transmitter module suitable for use in optical communications, which requires a satisfactory high frequency characteristic.
2. Description of the Related Art
As a prior art of a laser diode module equipped with an electricabsorption type optical modulator, such a configuration as shown in FIG. 10A has been disclosed in Japanese Published Unexamined Patent Application No. Hei 9-252164. In a hermetic package having an electric signal input terminal, there are provided a micro-strip line 3 connected to its corresponding signal pin 12 of the hermetic package 8 , a damping resistor (Rd) 2 B having one end electrically connected to the micro-strip line 3 and the other end electrically connected to a terminal resistor (Rt) 2 A, a modulator unit (hereinafter called “optical modulator” (MD)) 1 of a laser diode with a monolithically integrated electricabsorption optical modulator, which is electrically connected in parallel to the terminal resistor 2 A, and an optical system for coupling the output of the optical modulator 1 to an optical fiber 9 . These circuit configurations are formed over a sub-carrier 11 comprised of an insulator such as AlN. The sub-carrier 11 is further fixed to a carrier 6 and electrically grounded. Furthermore, a photodiode for optical power control 5 is fixed onto the carrier 6 . A Peltier element used for cooling and a temperature monitoring thermistor 7 are also provided within the hermetic package.
FIG. 10B is a top view showing the sub-carrier 11 in a developed form. The laser diode 1 is fixed onto a grounding electrode pattern 13 . The strip line 3 , the terminal resistor 2 A and the damping resistor 2 B are also formed by evaporating a metal thin film onto the sub-carrier.
In the prior art, the optical modulator 1 is defined as being capable of being described by a capacitance component alone, and the impedance of the optical modulator 1 is reduced with respect to a high frequency input electric signal. Therefore, the damping resistor 2 B is inserted into the package to thereby reduce impedance mismatching at a high frequency and lessen a return loss. The reduction in impedance mismatching at the high frequency is achieved even by connecting the damping resistor (Rd) in parallel with the terminal resistor (Rt) as in the case of a configuration example shown in FIG. 12 (circuit example shown in FIG. 13 ).
Originally, lessening the return loss in the input electric signal of the optical transmitter module is a technique extremely important for the purpose of accurately converting the waveform of the input electric signal to the waveform of a light signal. It is therefore necessary to accurately describe an equivalent circuit of the optical transmitter module including the optical modulator 1 . The known reference referred to above discloses that the optical modulator 1 can be described by the capacitance component alone as mentioned above. However, the equivalent circuit of the optical modulator 1 cannot be essentially described by capacitance alone. It is necessary to describe a photo-carrier generated upon light absorption in the form of an equivalent circuit.
FIG. 5A is an equivalent circuit described in consideration of a photo-carrier generated upon light absorption. As shown in the same drawing, the equivalent circuit can be described by connecting a voltage depend current source in parallel with a capacitor. Further, the voltage depend current source can approximately be replaced by a resistor as shown in FIG. 5 B. At this time, the amount of a reduction in the impedance of the modulator unit changes according to the magnitude of an amount-of-change ratio (=1/Rph) of a current bearing a photo-carrier to a voltage applied across the modulator. When the intensity of light inputted to the modulator actually increases, the present ratio, i.e., Rph becomes small, thereby leading to a large reduction in impedance. Such a reduction in impedance due to the photo-current becomes pronounced from a relatively low frequency domain. Therefore, the prior art is accompanied by a problem that the return loss increases due to the above-described impedance mismatching from the low frequency, so that the waveform of the electric signal is not converted to the waveform of the light signal with fidelity.
Further, the characteristic of a response to a light signal from an electric signal greatly varies within a band width in such a conventional configuration as shown in FIG. 11 . This is because resonance occurs due to a capacitance component included in an optical modulator and an inductance component included in a wire and hence peaking occurs in response as shown in FIG. 6 . The horizontal axis of FIG. 6 indicates the frequency of an input electric signal and the vertical axis thereof indicates an optical output response, respectively. Curves in the same drawing, each of which is indicative of the relationship between the input electric signal and the light output signal, differ in shape according to the intensity of light inputted to the optical modulator as in the case of three curves illustrated in the same drawing, for example. Further, A in the same drawing indicates a deviation in band width. The deviation in band width means the rate of change in optical output response within a required band width. The more the deviation in band width becomes large, the more distortion of the waveform of the light output signal increases. FIG. 7 shows an example of a waveform of a light signal outputted from a module having such a large deviation in band width. The present example shows the result of simulation at the time that an ideal rectangular wave is inputted as an input electric signal. The horizontal axis in FIG. 7 indicates time, and the vertical axis indicates the intensity of light, respectively. If an optical output response to the frequency of the input electric signal is constant, then the input rectangular wave is to be outputted as a light signal as it is. However, projection like distortion occurs in the output light signal according to the deviation in band width in FIG. 6 as is understood from FIG. 7 . Further, the projection like distortion is large as the deviation in band width increases. Thus, the prior art is accompanied by a problem that a satisfactory light-signal waveform cannot be obtained with an increase in the deviation in band width.
SUMMARY OF THE INVENTION
An object of the present invention is to implement an optical transmitter module which solves the foregoing problems and is equipped with an optical modulator less reduced in impedance, which converts the waveform of an input electric signal to the waveform of an output light signal with fidelity, and by extension an optical transmitter module having a satisfactory high frequency characteristic, wherein even if the power of light inputted to an optical modulator changes, the waveform of a light signal is not distorted, i.e., the characteristic of a response to the light signal is not degraded.
Another object of the present invention is to implement an optical transmitter module which solves the above-described problems and is equipped with an optical modulator which provides a small deviation in band width and is hard to develop peaking in response, and which is capable of obtaining a satisfactory light-signal waveform.
In order to achieve the above objects, the present invention principally comprises an optical transmitter module which comprises an electricabsorption type optical modulator for modulating a light signal in response to an electric signal, a first resistor having one end connected to the optical modulator and the other end grounded, and a second resistor having one end connected to an input supplied with the electric signal and the other end connected to the optical modulator and the first resistor respectively, and wherein the second resistor and the optical modulator are connected to each other through a first inductance.
The optical transmitter module may include a high frequency line connected to the second resistor and for transferring the electric signal to the optical modulator.
The optical modulator and the first resistor may be connected to each other through a second inductance different from the first inductance. The optical modulator may be integrated into a semiconductor laser diode.
At least the optical modulator, the first resistor, the second resistor and the first inductance may be held in one package. In that case, the electric signal may be supplied from outside the package. Alternatively, the electric signal may be generated inside the package.
The value of the second resistor may range from over 3 Ω to under 25 Ω. Alternatively, the value of the first inductance may be set greater than or equal to 0.1 nH. Alternatively, the distance between the second resistor and the optical modulator may be set so as to be less than or equal to 7.5 mm.
The optical transmitter module is equipped with a first substrate, and a second substrate electrically isolated from the first substrate. The optical transmitter module may take a configuration wherein at least the optical modulator and the first resistor are provided over the first substrate, and at least the second resistor is provided over the second substrate.
The optical transmitter module is equipped with a first substrate, and a second substrate electrically isolated from the first substrate. The optical transmitter module may take a configuration wherein at least the optical modulator and the first resistor are provided over the first substrate, and at least the high frequency line and the second resistor are provided over the second substrate.
The first resistor and the second resistor may be placed on the sides opposite to each other with the optical modulator interposed therebetween.
The above, other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:
FIGS. 1A and 1B are respectively a module overall view showing a basic configuration of an optical transmitter module according to the present invention and a top view of a sub-carrier thereof;
FIG. 2 is an equivalent circuit diagram of the basic configuration of the optical transmitter module according to the present invention;
FIG. 3 is a diagram illustrating circuit configuration patterns at the time that optical modulators are connected by wire bonding;
FIG. 4 is a diagram for performing a comparison between high frequency characteristics based on circuit configurations;
FIGS. 5A and 5B are respectively equivalent circuit diagrams of optical transmitter modules according to the present invention, which have been taken into consideration photo-carriers;
FIG. 6 is a diagram showing an example of a high frequency response in which a deviation in band width is large;
FIG. 7 is a diagram illustrating an example of a light waveform in which a deviation in band width is large;
FIG. 8 is a configurational view of an optical transmitter module according to the present invention, wherein an impedance controlling resistor (damping resistor) is placed over another substrate;
FIG. 9 is a configurational view of an optical transmitter module according to the present invention, wherein a terminal resistor is placed over another substrate;
FIGS. 10A and 10B are respectively an overall configurational view of a module showing a first prior art and a top view of a sub-carrier thereof;
FIG. 11 is an equivalent circuit diagram of the first prior art;
FIGS. 12A and 12B are respectively an overall configurational view of a module showing a second prior art and a top view of a sub-carrier thereof;
FIG. 13 is an equivalent circuit diagram of the second prior art; and
FIG. 14 is a top view showing a sub-carrier of an optical transmitter module according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
FIG. 2 is an equivalent circuit diagram showing a basic configuration of an optical transmitter module according to the present invention. In the present invention, a resistor Rd for compensating for a reduction in impedance at a low frequency of a modulator unit (in which a modulator and a terminal resistor are connected in parallel), which occurs due to a photo-current incident to optical absorption, is included. Further, an inductance L 1 is connected to the resistor Rd to compensate for the impedance of the modulator unit, which is lowered at a high frequency, by connecting the inductance in series with the resistor Rd. Incidentally, since the impedance of L 1 increases in proportion to the frequency, it is useful for impedance matching at a high frequency.
FIG. 3 is a diagram showing circuit configuration patterns where optical modulators are connected by wire bonding. When wiring bonding having the advantage of simplicity in terms of implementation is used to form inductance and connect between optical modulators and high frequency transmission lines, the number of circuits substantially different in optical modulator, damping resistor (Rd), terminal resistor (Rt) and wire connecting method is eight types as shown in FIG. 3 . It has experimentally been confirmed that Rph of these is reduced to about 50 Ω to 100 Ω. Load impedances of these circuits can be described as approximately A=Rd+Rt*Rph/(Rt+Rph) in a low frequency region or domain as to four types (I) in the same drawing. Load impedances can be described as B=Rt*(Rd+Rph)/(Rt+Rd+Rph)=Rt*Rph/(Rt+Rph+Rd)+Rt*Rd/(Rt+Rph+Rd) as to four types (II) in the same drawing. If A>B, then the effect of greatly improving impedance matching is generally obtained even by the insertion of a damping resistor low in resistance. Inserting a very large damping resistor might exert a bad influence on an extinction ratio and a chirping characteristic of each optical modulator, thus making it impossible to transmit light over a long transmission distance. Therefore, the four types (II) are considered to be poor in feasibility. Thus, numerical values have been analyzed with objects being limited to the circuit configurations of the four types (I).
FIG. 4 shows the result of their analyses. Of the four types (I), return losses and deviations in band width were calculated and compared in consideration of even the influence of wire's inductance. It was thus confirmed that the configurations of the present invention would be substantially superior to other configurations in these characteristics as shown in FIG. 4 . Now, I-A and I-B correspond to the circuit configurations of the present invention respectively. I-C shows a circuit configuration of the first prior art shown in FIG. 11, and I-D is basically identical to a circuit configuration of the second prior art shown in FIG. 13 . The following parameters were used upon calculation of the present table. L 1 =0.7 nH, L 2 =0.7 nH, L 3 =0.6 nH, C=0.6 pF, Rt=50 Ω, and Rd=15 Ω respectively. Rph was changed in parameter within a range of 50 Ω to 100 Ω. The means of return losses and the maximum and minimum of a deviation in band width have taken the means and the maximum and minimum with respect to Rph respectively. Further, the relationship between superiority and inferiority shown in FIG. 4 no changes within parameter ranges of at least L 1 , L 2 and L 3 =0.2 nH to 1.0 nH, C=0.4 pF to 1.0 pF, Rt=50 Ω to 70 Ω and Rd=3 Ω to 25 Ω. Thus, it became evident that the configurations of I-A and I-B were effective and most suitable for improving return losses and deviations in band width to be set as targets as methods of connecting the damping resistor (Rd), terminal resistor (Rt), the capacitance (C) of an optical modulator, Rph based on a photo-current, and inductances (L 1 , L 2 and L 3 ) for wire boding. Described specifically, the present configurations could obtain a 39% improvement in return loss and a 48% improvement in deviation in band width as compared with the configuration (I-C) of the first prior art.
FIG. 1 is a view showing a first embodiment of an optical transmitter module according to the present invention. A semiconductor laser diode with a monolithically integrated optical modulator 31 is placed over an AlN-made sub-carrier 32 . Further, the sub-carrier 32 is fixed to a carrier 33 by solder. Furthermore, the carrier 33 is placed over a Peltier cooler 34 and accommodated within a metal storage or holding case 35 .
FIG. 2 is a top view of the sub carrier 32 . A laser oscillator and an optical modulator are integrated into a semiconductor laser diode 31 . An electrode (electrode of optical modulator) 38 to which a high frequency modulation signal is inputted, and an electrode 39 to which a laser oscillation voltage is applied, are provided on the upper surface side of a laser chip 31 . There is further provided a grounding electrode 40 on the lower surface side of the chip 31 . A grounding electrode pattern 41 , a first micro-strip line 42 for transferring an input electric signal, wire bonding regions or areas 43 and 44 , an impedance controlling resistor (damping resistor) 45 , and a terminal resistor 46 are formed over the sub-carrier by a metal thin film. Further, a grounding electrode is provided even over the reverse side or back of the sub-carrier 32 , and fixed to the carrier 33 made of CuW and grounded. The grounding electrode is electrically connected to the back thereof by defining holes 47 in AlN. As shown in FIGS. 1A and 1B, a series connection of the terminal resistor 46 and a wire inductance (L 2 ), and the electrode of the optical modulator 38 are connected in parallel. One thereof is grounded and the other is connected to the wire inductance (L 1 ) and the impedance controlling resistor in series with the parallel connection.
The input electric signal is supplied to each of terminals 36 . Each of leads shielded by an insulator extends through side walls of the holding case 35 . The lead is connected to a second micro-strip line 37 formed over the AlN by solder. The input electric signal is transferred to the first micro-strip line 42 placed on the sub-carrier 32 through the second micro-strip line 37 , whereby the optical modulator 38 is driven.
The carrier 33 having such a high frequency circuit is placed over the Peltier cooler 34 . Further, the Peltier cooler 34 is fixed to the bottom of the holding case 35 . When a predetermined current is supplied via leads 49 and 50 of the Peltier cooler 34 , the absorption of heat occurs on the upper side of the Peltier cooler 34 , so that the sub-carrier 32 and semiconductor laser chip 31 on the carrier 33 can be cooled. While heat corresponding to the absorbed heat is generated on the lower side of the Peltier cooler 34 at this time, the heat is diverged into the outside through the case 35 . Further, designated at numeral 51 in FIG. 1A is a thermistor which monitors the temperature through the use of a resistor and keeps a driving temperature of a laser constant.
Further, a wire 48 shown in FIG. 1B is a wire or interconnection for driving the laser at a constant optical output. Designated at numeral 52 in FIG. 1A is a photodiode, which monitors the intensity of light emitted from the side opposite to the modulator 38 of the laser chip to thereby keep the power of light outputted from the laser unit 39 constant. Reference numeral 53 indicates an aspherical lens used for fiber connection, reference numeral 54 indicates an isolator, and reference numeral 55 indicates a single mode fiber, respectively.
According to the present embodiment, an advantageous effect can be brought about in that an optical transmitter module for faithfully converting the waveform of an electric signal small in return loss to an optical signal waveform can be provided or offered.
FIG. 8 is a view showing a second embodiment of the present invention and is a view showing a a configuration of an optical transmitter module wherein an impedance controlling resistor (damping resistor) is mounted on another substrate. The same elements of structure as those employed in the first embodiment are identified by like reference numerals. The impedance controlling resistor is formed over a substrate different from that for a sub-carrier 32 with a laser chip 31 mounted thereon. Rph, the capacitance (C), an extinction ratio and a chirping characteristic of the laser chip 31 are measured in a state of being placed over the sub-carrier 32 . Further, suitable resistance values are determined based on the result of measurement, and the resistor is integrated into the module shown in FIG. 8, whereby the configuration of the present embodiment can be obtained. An insulating substrate (SI substrate) can be used as another substrate referred to above.
The impedance controlling resistor is formed over the substrate 37 different from that for the sub-carrier 32 equipped with the laser chip 31 . Under this state, Rph, the capacitance (C), the extinction ratio and the chirping characteristic of the laser chip 31 are measured in the state of being placed over the sub-carrier 32 , and the suitable resistance values are determined based on the resultant data. In this condition, Rd is wired by metal wires and integrated into the module as shown in FIG. 12 B. It is thus possible to obtain a module which is inexpensive and has a satisfactory high frequency characteristic. Here, the sub-carrier 32 is fixed to a chip carrier 33 by solder. Further, the chip carrier 33 is mounted on a Peltier cooler 34 and held within a metal holding or storage case 35 . A laser oscillator and an optical modulator are integrated into a semiconductor laser diode 31 . An electrode (electrode of optical modulator) to which a high frequency modulation signal is inputted, and an electrode to which a laser oscillation voltage is applied, are provided on the upper surface side of the laser chip 31 . There is further provided a grounding electrode on the lower surface side of the chip 31 . A grounding electrode pattern, a first micro-strip line for transferring an input electric signal, wire bonding regions or areas, an impedance controlling resistor, and a terminal resistor are formed over the sub-carrier by a metal thin film. A grounding electrode is also provided even over the reverse side or back of the sub-carrier. The grounding electrode is fixed to the carrier 33 made of CuW and simultaneously grounded. Further, the grounding electrode is electrically connected to the back thereof by defining holes in AlN. Circuit configurations of these parts are represented as shown in FIG. 5A or 5 B. Namely, a series connection of the terminal resistor and a wire inductance (L 2 ), and the optical modulator are connected in parallel. One thereof is grounded and the other is connected to a wire inductance (L 1 ) and the impedance controlling resistor in series with the parallel connection.
The input electric signal is supplied to each of terminals. Each of leads shielded by an insulator extends through side walls of the holding case 35 . The lead is connected to a second micro-strip line 37 formed over the AlN by solder. The input electric signal is transferred to the first micro-strip line 42 placed on the sub-carrier 32 through the second micro-strip line 37 , whereby the optical modulator is driven.
The carrier 33 having such a high frequency circuit is placed over the Peltier cooler 34 . Further, the Peltier cooler 34 is fixed to the bottom of the holding case 35 . When a predetermined current is supplied via leads of the Peltier cooler 34 , the absorption of heat occurs on the upper side of the Peltier cooler 34 , so that the sub-carrier 32 and semiconductor laser chip 31 on the carrier 33 can be cooled. While heat corresponding to the absorbed heat is generated on the lower side of the Peltier cooler 34 at this time, the heat is diverged into the outside through the case 35 .
Reference numeral 53 indicates an aspherical lens used for fiber connection, reference numeral 54 indicates an isolator, and reference numeral 55 indicates a single mode fiber, respectively.
According to the present embodiment, an advantageous effect can be brought about in that an optical transmitter module having a satisfactory high frequency characteristic can be implemented at low cost.
FIG. 9 is a view showing a third embodiment of the present invention and is a view illustrating a configuration of an optical transmitter module wherein a terminal resistor is placed on another substrate. The same elements of structure as those employed in the first embodiment are identified by the same reference numerals. In a manner similar to the second embodiment, the terminal resistor is formed over another substrate without being formed over a sub-carrier 32 as shown in FIG. 9 to thereby allow an adjustment to the terminal resistor. An insulating substrate (SI substrate) can be used as another substrate referred to above in a manner similar to the second embodiment.
As shown in FIG. 9 in a manner similar to the second embodiment, the terminal resistor is formed over another insulating substrate other than the sub-carrier 32 to thereby permit the adjustment to the terminal resistor, whereby a module is obtained which is inexpensive and has a satisfactory high frequency characteristic. Here, the sub-carrier 32 is fixed to a chip carrier 33 by solder. Further, the chip carrier 33 is mounted on a Peltier cooler 34 and held within a metal holding or storage case 35 . A laser oscillator and an optical modulator are integrated into a semiconductor laser diode 31 . An electrode (electrode of optical modulator) to which a high frequency modulation signal is inputted, and an electrode to which a laser oscillation voltage is applied, are provided on the upper surface side of the laser chip 31 . There is further provided a grounding electrode on the lower surface side of the chip 31 . A grounding electrode pattern, a first micro-strip line for transferring an input electric signal, wire bonding regions or areas, an impedance controlling resistor, and a terminal resistor are formed over the sub-carrier by a metal thin film. A grounding electrode is also provided even over the reverse side or back of the sub-carrier. The grounding electrode is fixed to the carrier 33 made of CuW and simultaneously grounded. Further, the grounding electrode is electrically connected to the back thereof by defining holes in AlN. Circuit configurations of these parts are given as shown in FIG. 5A or 5 B. Namely, a series connection of the terminal resistor and a wire inductance (L 2 ), and the optical modulator are connected in parallel. One thereof is grounded and the other is connected to a wire inductance (L 1 ) and the impedance controlling resistor in series with the parallel connection.
The input electric signal is supplied to each of terminals. Each of leads shielded by an insulator extends through side walls of the holding case 35 . The lead is connected to a second micro-strip line 37 formed over the AlN by solder. The input electric signal is transferred to the first micro-strip line 42 placed on the sub-carrier 32 through the second micro-strip line 37 , whereby the optical modulator is driven.
The carrier 33 having such a high frequency circuit is placed over the Peltier cooler 34 . Further, the Peltier cooler 34 is fixed to the bottom of the holding case 35 . When a predetermined current is supplied via leads of the Peltier cooler 34 , the absorption of heat occurs on the upper side of the Peltier cooler 34 , so that the sub-carrier 32 and semiconductor laser chip 31 on the carrier 33 can be cooled. While heat corresponding to the absorbed heat is generated on the lower side of the Peltier cooler 34 at this time, the heat is diverged into the outside through the case 35 .
Reference numeral 53 indicates an aspherical lens used for fiber connection, reference numeral 54 indicates an isolator, and reference numeral 55 indicates a single mode fiber, respectively.
According to the present embodiment, an advantageous effect can be brought about in that a module having a satisfactory high frequency characteristic can be implemented at low cost.
FIG. 14 is a view showing a fourth embodiment of the present invention and is a top view of a sub-carrier employed in one embodiment of an optical transmitter module of the circuit type (I-A (FIG. 3 )). In the present embodiment, a gold wire and a ribbon wire are used as wire inductances (L 1 ) and (L 2 ) respectively. Other configurations in the module are similar to those employed in the first embodiment. The same elements of structure as those employed in the first embodiment are identified by the same reference numerals.
An electrode 38 (electrode of optical modulator) to which a high frequency modulation signal is inputted, and an electrode 39 to which a laser oscillation voltage is applied, are provided on the upper surface side of a laser chip 31 . There is also provided a grounding electrode 40 on the lower surface side of the chip 31 . Further, an electrode 47 for transferring a high frequency to a terminal resistor is provided over the chip and connected to the terminal resistor through the use of a ribbon wire (L 2 ) having an inductance of 001 nH or less. Since the value of the inductance of the ribbon wire is small at this time, the influence thereof is low. This is not described on a circuit diagram. A grounding electrode pattern 41 , a first micro-strip line 42 for transferring an input electric signal, wire bonding regions or areas 43 and 44 , an impedance controlling resistor 45 , and a terminal resistor 46 are formed over the sub-carrier by a metal thin film. A grounding electrode is also provided even over the reverse side or back of the sub-carrier. The grounding electrode is fixed to a carrier 33 made of CuW and simultaneously grounded. Further, the grounding electrode is electrically connected to the back thereof by defining holes 47 in AlN. Circuit configurations of these parts are given as shown in FIG. 6A or 6 B. Namely, the terminal resistor 46 and the optical modulator 38 are connected in parallel. One thereof is grounded and the other is connected to a wire inductance (L 1 ) and the impedance controlling resistor in series with this parallel connection.
According to the present embodiment, an advantageous effect can be brought about in that a module having a satisfactory high frequency characteristic can be implemented at low cost.
Incidentally, the present invention is not limited to the respective embodiments referred to above. It is needless to say that all sorts of changes can be made according to the difference between high frequency transfer characteristics. While, for example, AlN has been selected as a material for the sub-carrier in the above-described embodiment, the present invention is not limited to it. Other materials such as AlO 3 , etc. can also be selected as the material. While the gold wire is used as an inductance element in the above-described embodiment, the present invention is not necessarily limited to it. It may be set as a wire or interconnection on a sub-carrier substrate.
According to the present invention, return losses can be reduced over a wide frequency range of from a low frequency domain to a high frequency domain in a transmitter module for optical communications. Even if an optical output is greatly changed, a satisfactory response characteristic in which a return loss in input electric signal is low, can be obtained, thus making it possible to offer or provide an optical transmitter module satisfactory in high frequency characteristic.
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In order to obtain an optical transmitter module for converting an input electric signal to a light signal with fidelity and outputting it therefrom, a terminal resistor Rt and an optical modulator MD are connected in parallel within a package including a laser diode with a monolithically integrated optical modulator for obtaining the light signal according to the electric signal. One thereof is grounded and the other thereof is connected to a wire inductance (L 1 ) and an impedance matching resistor Rd in series with this parallel connection. Further, a high frequency transmission line (micro-strip line) MSL for the transmission of the electric signal is connected to the other end of the impedance matching resistor Rd.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image forming device such as a copy machine, a facsimile machine and a printer, and an image forming method.
[0003] 2. Description of the Related Art
[0004] In a conventional laser printer known as an image forming device, when an electrostatic latent image is formed on a photoconductive body by using 100% light energy even on an inner part of a black solid part of the image, a large amount of toner adheres to the photoconductive body. Not only is the toner consumed in a large amount, but there is also a drawback of deterioration in the quality of the image recorded on paper, such as trailing of the toner. In consideration of such a drawback, by using a matrix of pixels, depending on whether surrounding pixels are white or black, a determination can be made as to whether a target pixel is located at a peripheral part or at an inner part of the black solid part. An exposing energy for pixels located in the black solid part is reduced in order to reduce an amount of toner adhered to the photoconductive body. This technology is generally known as “Toner Saving”.
[0005] In the above-described technology, by using the matrix of pixels consisting of the target pixel and the surrounding pixels, depending on whether the surrounding pixels are white or black, a determination can be made as to whether or not to reduce the light energy of the target pixel. In fact, a value of the surrounding pixels is arranged in one piece of data and this piece of data is input to a memory as an address. The exposing energy is reduced in accordance with this piece of data output from the memory. That is, the toner is saved for the target pixel.
[0006] However, since it becomes necessary to provide a memory, the scale of the circuitry increases. In particular, to improve accuracy for determining whether the target pixel is located at the peripheral part or at the inner part of the black solid part, the size of the matrix increases and a greater capacity of the memory becomes necessary. Meanwhile, when image data becomes multilevel, the number of bits of data as the address increases and a greater capacity of memory becomes necessary.
SUMMARY OF THE INVENTION
[0007] An advantage of the present invention is to provide an image forming device and an image forming method which can determine whether or not to save toner for a target pixel by simple circuitry.
[0008] According to an aspect of the present invention, the image forming device includes a plurality of holding units that holds data of pixels around a target pixel, a weight generating unit that generates a weight for each holding unit, a plurality of weight applying units that applies a corresponding weight to the data held by each holding unit, and a control unit that determines an exposing energy for the target pixel in accordance with an output of each weight applying unit.
[0009] In the present invention, the weight applying unit is a multiplier that multiplies the data and the weight. The control unit includes an adder that adds the output of each weight applying unit. The control unit can compare the output of the adder with one or more reference and determine the exposing energy for the photoconductive body. Depending on how the weight is applied, a sense of direction can be given to saving of an edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a block diagram showing a configuration of a Multi-Function Peripheral (MFP) according to an embodiment of the present invention.
[0011] [0011]FIG. 2 is a block diagram showing an accumulator for pixel data in an image processing circuit for a printer of the MFP.
[0012] [0012]FIG. 3 is a block diagram showing an exposing energy controller in the image processing circuit for the printer of the MFP.
[0013] [0013]FIG. 4 is a flow diagram for describing data accumulation with respect to surrounding pixels of a target pixel in the accumulator of the pixel data in the image processing circuit for the printer.
[0014] [0014]FIG. 5 is a table for describing selection of a signal of different duty ratios in the controller of the exposing energy in the image processing circuit for the printer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Embodiments of the present invention will be described. FIG. 1 shows a configuration of a MFP (including multi-functions such as a copy function, a facsimile function and a scanning function) according to an embodiment of the present invention.
[0016] The MFP includes a Micro Processor Unit (MPU) 1 , a Network Control Unit (NCU) 2 , a MODEM 3 , a Read Only Memory (ROM) 4 , a Random Access Memory (RAM) 5 , an image memory 6 , a scanner (image scanning unit) 7 , an operation unit 8 , a display 9 , a Coder and Decoder (CODEC) 10 , a printer CODEC 11 , an image processing circuit for a printer 12 , a page memory 13 , a Laser Scan Unit (LSU) 14 , a mechanism controller for a printer 15 , a system bus 16 and an image bus 17 .
[0017] The MPU 1 includes a function for controlling the entire MFP in accordance with a program stored in the ROM 4 . The NCU 2 and the MODEM 3 are connected to the MPU 1 . The NCU 2 is controlled by the MPU 1 . The NCU 2 controls a connection between a communication line 18 and the MFP. The NCU 2 includes a function for transmitting a dial pulse according to a telephone number of another party of a communication, and a function for detecting a ring signal. Further, the communication line 18 is connected to a Public Switched Telephone Network (PSTN).
[0018] The MODEM 3 modulates transmission data and demodulates received data. Specifically, the MODEM 3 modulates the transmission data which is a digital signal, into an analog audio frequency signal. Then, the MODEM 3 transmits the analog audio frequency signal to the communication line 18 via the NCU 2 . The MODEM 3 also demodulates into a digital signal, an analog audio frequency signal received from the communication line 18 via the NCU 2 . The ROM 4 stores in advance, programs or the like for controlling an operation of the entire MFP. For example, the RAM 5 stores data necessary for the control by the MPU 1 and data necessary to be stored temporarily. The image memory 6 stores image data scanned by the scanner 7 and also stores image data received from a remote device via the communication line 18 and the MODEM 3 .
[0019] The scanner 7 scans a shading plate or an image of an original document and converts the scanned data into an electric signal. The scanner 7 executes various processes on image data scanned by a Charge Coupled Device (CCD) line image sensor.
[0020] The operation unit 8 includes a start key, a mode switching key for switching modes between a copy mode and a facsimile mode or the like, a ten-key numeric pad for inputting numbers such as a telephone number, a speed dial key, and keys for instructing various operations. The display 9 displays various pieces of information such as a telephone number input from the operation unit 8 and a remaining amount of toner of the printer.
[0021] The CODEC 10 encodes the image data scanned from the original document and the stored image data in accordance with Modified Huffman (MH), Modified Read (MR) and Modified MR (MMR) schemes or the like for transmitting the image data. The printer CODEC 11 decodes the encoded image data for printing the received image data and the data scanned from the original document.
[0022] The image processing circuit for the printer 12 controls image processing when printing the received image data, the scanned image data or the like. The image processing circuit for the printer 12 includes a toner saving circuit 12 a . The page memory 13 stores the image data to be printed. The LSU 14 controls a printing operation of a laser printer in accordance with a signal from the image processing circuit for the printer 12 . The mechanism controller for the printer 15 controls supplying, transporting, etc. of paper to the printer.
[0023] The toner saving circuit 12 a consists of an accumulator 21 that accumulates data of surrounding pixels for the target pixel shown in FIG. 2, and an exposing energy controller 22 shown in FIG. 3. The data accumulator 21 shown in FIG. 2 is made of the following circuits (i)-(vii):
[0024] (i) Latches 31 - 11 , 31 - 21 and 31 - 31 which store for each pixel, image data V-Data that is input serially, and a line memory 32 which stores image data for one line output from the latch 31 - 31 ,
[0025] (ii) Latches 31 - 12 , 31 - 22 and 31 - 32 which store for each pixel, the stored data of the line memory 32 input serially,
[0026] (iii) A line memory 33 which stores image data for one line output from the latch 31 - 32 , and latches 31 - 13 , 31 - 23 , . . . and 31 - 33 which store for each pixel, the stored data of the line memory 33 input serially,
[0027] (iv) Registers 34 - 11 , 34 - 21 , and 34 - 33 which are provided for each of the latches 31 - 11 , 31 - 21 , . . . and 31 - 33 (excluding 31 - 22 ) respectively, and store a weight coefficient of each of the surrounding pixels,
[0028] (v) Gate circuits 35 - 11 , 35 - 21 , . . . and 35 - 33 which are provided for each of the latches 31 - 11 , 31 - 21 , . . . and 31 - 33 (excluding 31 - 22 ) respectively, and when a stored value of the corresponding latch is “1”, derive an output of the corresponding register,
[0029] (vi) An address decoder 36 which applies a selection signal to each of the registers 34 - 11 , 34 - 21 , . . . and 34 - 33 , and
[0030] (vii) An adder 37 which adds after receiving each output from the gate circuits 35 - 11 , 35 - 21 , . . . and 35 - 33 .
[0031] The address decoder 36 is used when storing the weight coefficient in each of the registers 34 - 11 , 34 - 21 , . . . and 34 - 33 . The MPU 1 selects one of the registers 34 - 11 , 34 - 21 , . . . and 34 - 33 by outputting an address to the address decoder 36 , and writes in the weight coefficient to the selected register. This process is normally carried out when power is turned on or when starting a print job.
[0032] Suppose that in the pixels of a 3×3 matrix shown in FIG. 4, pixel data of a target pixel I is input to the data accumulator 21 . Further, the weight coefficient for pixels (b), (d), (e) and (g) that are adjacent vertically and horizontally to the target pixel I is 2 , and the weight coefficient for pixels (a), (c), (j) and (h) in a diagonal direction is 1 .
[0033] For example, when each of pixels Va, Vb, . . . and Vh of the input image data V-Data has a value of “1”, “1” is stored in each of the latches 31 - 11 , 31 - 21 , . . . and 31 - 33 . Therefore, all of the gate circuits 35 - 11 , 35 - 21 , . . . and 35 - 33 are at an opened state. The value “2” is output from each of the registers 34 - 21 , 34 - 12 , 34 - 32 and 34 - 23 and the value “1” is output from each of the registers 34 - 11 , 34 - 21 , 34 - 13 and 34 - 33 . The outputs are input to the accumulator 35 , and an additional value of 12 is output.
[0034] As another example, among the input image data V-Data, when the pixels Va, Vd, Vf and Vg have a value of “0” and the other pixels Vb, Vc, Ve and Vh have a value of “1”, “1” is stored in the latches 31 - 21 , 31 - 31 , 31 - 32 and 31 - 33 . Accordingly, only the gate circuits 35 - 21 , 35 - 31 , 35 - 32 and 35 - 33 are opened. The value “2” is output from each of the registers 34 - 21 and 34 - 23 via the gate circuits 35 - 21 and 35 - 23 respectively, a value of “1” is output from each of the registers 34 - 31 and 34 - 33 via the gate circuits 35 - 31 and 35 - 33 respectively, and an additional value of 6 is output from the adder 37 .
[0035] As another example, among the input image data V-Data, when the pixels Va and Vf have a value of “1” and thus the pixels Vb, Vc, Vd, Ve, Vg and Vh have a value of “0”, “1” is stored in each of the latches 31 - 11 and 34 - 13 , and only the gate circuits 35 - 11 and 35 - 13 are opened. The value of “ 1 ” is output from each of the registers 34 - 11 and 34 - 13 respectively and an additional value of 2 is output from the adder 37 .
[0036] As shown in FIG. 3, the exposing energy controller 22 includes a selector 41 that receives an input of an additional value output from the adder 37 and outputs a duty ratio signal according to the additional value, a duty ratio 100% signal generator 42 , a duty ratio 75% signal generator 43 , a duty ratio 50% signal generator 44 and a duty ratio 25% signal generator 45 . The selector 41 includes a storage unit 41 a of a lookup table that associates an output value of the adder 37 with a duty ratio to be selected (refer to FIG. 5). The selector 41 selects a duty ratio signal according to the output value (additional value) of the adder 37 .
[0037] When the additional value is 12 as in the above-described example of the output of the data accumulator 21 , the selector 41 selects and outputs a signal of the duty ratio 25% signal. The duty ratio 25% signal is applied to a laser diode driver 46 , and a laser diode 47 is driven by the signal. In this case, the target pixel corresponds to the black solid region of the image, the toner is saved for the target pixel and the image is printed.
[0038] When the additional value of 6 is input to the selector 41 , the duty ratio 75% signal is selected and output. In this case, the target pixel having a meaning of an edge enhancement is printed. When the additional value of 2 is input to the selector 41 , the duty ratio 100% signal is selected and output.
[0039] Further, in the above-described embodiment, each pixel of the image data is binary data. However, the present invention can be applied even when each pixel is multilevel data. In case the image data is multilevel, a multiplier can be used in place of each of the gates 35 - 11 , 35 - 12 , . . . and 35 - 33 shown in FIG. 2. Furthermore, when the weight coefficient is 2, the multiplier can be exchanged with a bit shift circuit. Even when the image data is binary data, if the weight coefficient can be a fixed value, the weight coefficient can be set by a wired-logic when designing the circuit. As a result, the registers and the address decoder become unnecessary and the circuitry can be simplified even more.
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An image forming device includes a plurality of holding units that holds data of pixels around a target pixel, a weight generating unit that generates a weight for each holding unit, a plurality of weight applying units that applies a corresponding weight to the data held by each holding unit, and a control unit that determines an exposing energy for the target pixel in accordance with an output of each weight applying unit.
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BACKGROUND
[0001] Radiation therapy plans are generated based in large part on a patient's physical parameters. The design of the plan may be complicated as numerous treatment parameters can be defined to address the particular physical characteristics of the patient. If an initial candidate radiation treatment plan can be efficiently devised, overall quality of care may increase correspondingly as it may be simpler and faster for caregivers or computers to modify this initial candidate plan into the final course of treatment that will be used to treat the patient.
SUMMARY OF THE INVENTION
[0002] A non-transitory computer-readable storage medium stores a set of instructions executable by a processor. The set of instructions is operable to receive a current patient medical image of a current patient. The set of instructions is further operable to compare the current patient medical image to a plurality of previous patient medical images. Each of the previous patient medical images corresponds to a previous patient. The set of instructions is further operable to select one of the previous patients based on a geometric similarity between the previous patient medical image of the selected one of the previous patients and the current patient medical image. The set of instructions is further operable to determine an initial radiation treatment plan based on a radiation treatment plan of the selected one of the previous patients.
[0003] A system includes a medical imager, a previous patient database, a similarity search system, and a plan generation system. The medical imager generates a current patient medical image for a current patient. The previous patient database stores data relating to a plurality of previous patients. The data relating to each of the previous patients includes a medical image relating to each of the previous patients and a radiation treatment plan relating to each of the previous patients. The similarity search system determines a similarity score for each of the plurality of the previous patients. The similarity score for each of the previous patients is determined based on a geometric similarity between the medical image corresponding to each of the previous patients and the current patient medical image. The plan generation system determines an initial radiation treatment plan for the current patient based on a radiation treatment plan for a selected one of the plurality of previous patients. The selected one of the plurality of previous patients is selected based on the similarity score of the selected one of the plurality of previous patients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 illustrates a system for automatic generation of initial radiation treatment plans according to an exemplary embodiment.
[0005] FIG. 2 illustrates a method for automatic generation of initial radiation treatment plans according to an exemplary embodiment.
[0006] FIG. 3 illustrates a display of radiation treatment plans for current and prior patients according to an exemplary embodiment.
DETAILED DESCRIPTION
[0007] The exemplary embodiments of the present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The exemplary embodiments describe systems and methods by which initial radiation treatment plans for a patient receiving radiation therapy are automatically generated.
[0008] Prior to initiating radiation therapy for a patient, a number of steps must be taken. A radiation oncologist, dosimetrist, or other appropriate medical professional (referred to herein as a “planner”) must identify the target volume to be irradiated, as well as organs and tissues to be spared from radiation (also referred to herein as “organs at risk”). These areas are typically indicated on computed tomography (CT) images, magnetic resonance images (MRI), positron emission tomography (PET) images, x-ray images, single photon emission computed tomography (SPECT) images, or ultrasound images, and may be drawn with or without computer assistance in defining their boundaries. The planner may further define constraints on the amount of radiation to be delivered to target and healthy tissue. Once this has been determined, the modality (e.g., photon, electron), quantity, beam orientation, beam energy and beam modifiers (e.g., blocks, wedges) of the radiation sources are then set to define an initial candidate treatment plan.
[0009] The planning process then proceeds iteratively from this candidate treatment plan. At the initial step and each subsequent step, the radiation dose resulting from the plan is computed throughout the patient volume. The parameters of the radiation therapy, as discussed above, are then adjusted iteratively until the desired dose constraints are achieved and the planner judges the plan to be satisfactory. The above framework applies both to 3D conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT). The adjustment process may proceed with or without computer assistance in determining the updates to the parameters of the radiation therapy plan. The definition of the initial plan by the planner is important because a well-designed initial plan may reduce the time required to optimize treatment for the patient. Further, the quality of the final radiation therapy plan may vary depending on the quality of the manually-created initial plan, leading to the potential for variation in quality of care depending on the caregiver. The exemplary embodiments address these flaws by using patient geometry and other parameters to automatically generate an initial therapy plan.
[0010] FIG. 1 illustrates a schematic view of an exemplary system 100 . The lines connecting the elements shown in FIG. 1 may be any type of communications pathway suitable for conveying data between the elements so connected. The system 100 includes scanning equipment 110 for obtaining images of a current patient for whom radiation treatment is currently being planned. The scanning equipment 110 may be a CT scanner, an MRI imager, a PET imager, an x-ray scanner, a SPECT imager, an ultrasound imager, or may be any of the various other types of medical imaging devices known in the art. The scanning equipment 110 is communicatively coupled with a treatment planning workstation 120 , which is a computing system (e.g., a combination of hardware and software such as a processor and software instructions which are executable by the processor to carry out certain functions) used by a planner to plan radiation treatment for the current patient. The treatment planning workstation 120 is similar to known systems presently used by planners, except as will be described hereinafter.
[0011] The treatment planning workstation 120 receives patient images from the scanning equipment 110 and transmits the patient images to a similarity search engine 130 . The similarity search engine 130 also retrieves data on previous patients from a previous patient database 140 , which is then compared to the images of the current patient as will be described in further detail hereinafter. It is possible the previous patient database 140 to store information in a repository using known medical informatics standards such as DICOM or DICOM-RT. Data stored for previous patients may include medical images (e.g., CT, MRI, PET, x-ray, SPECT, ultrasound, etc.), geometric definition of the target structure (e.g., a tumor to be irradiated), identification of organs at risk (e.g., organs that should not be irradiated), and a treatment plan used for the prior patient. This includes the modality of radiation, the number of radiation sources, the energy of each beam, modifiers used, and intensity maps. In some instances, the radiation treatment plan stored for each previous patient is a final treatment plan that has concluded after the initial treatment plan for the patient has been refined. Additionally, the information stored in the previous patient database 140 for each patient may include further relevant information such as age, patient medical history, patient's family medical history, further information about the patient's current condition, other treatment currently being administered to the patient (e.g., chemotherapy), or any other information that may be relevant for the planner to design a course of radiation treatment for the current patient.
[0012] Some or all of the data relating to previous patients is then transmitted from the similarity search engine 130 to a plan generation system 150 , which generates a plan for the current patient based on the data relating to previous patients, as will be described in farther detail hereinafter. The plan generation system 150 is also coupled with the treatment planning workstation 120 , in order that its output may be returned to the planner who is using the treatment planning workstation. Those of skill in the art will understand that the similarity search engine 130 , the previous patient database 140 , and the plan generation system 150 may be implemented in various ways, including as elements of the treatment planning workstation 120 , or as separate hardware and/or software components, without impacting their functions, or any combinations thereof. For example, the similarity search engine 130 may include a processor and software containing instructions executable by the processor. The previous patient database 140 may be embodied on a server having a storage device array and a relational database, or other type of commonly used database structure.
[0013] FIG. 2 illustrates an exemplary method 200 for automatically generating an initial radiation treatment plan for a current patient, which will be described herein with reference to the exemplary system 100 of FIG. 1 . In step 210 , the scanning equipment 110 is used to obtain images of the current patient. As discussed above, the images obtained may be CT images, MRI images, or any other type of medical imaging. Typically, the images are a series of two-dimensional cross-sections from which a three-dimensional representation of the patient may be understood. However, in some cases it may be appropriate to include the use of a single two-dimensional image, or to include the use of a three-dimensional model, without departing from the broader concepts described by the exemplary embodiment. Alternatively, the current patient medical images may have been previously recorded, using a device such as the scanning equipment 110 , and may be retrieved at this stage of the method 200 .
[0014] In step 220 , feature extraction is performed on the current patient images using the similarity search engine 130 . This may involve the identification of various structures (e.g., tumors, organs, bones, etc.) indicated by the images, and determination of the volumes, shape, morphology and texture of each of the features. This proceeds using feature extraction algorithms, many of which are known in the art, and results in the generation of a feature vector representing a plurality of features indicated in the current patient images.
[0015] In step 230 , the current patient's feature vector is compared to feature vectors of previous patients, for whom relevant data is stored in the previous patient database 140 . In the exemplary embodiment, feature extraction results for previous patients are stored in the form of feature vectors in the previous patient database 140 ; in another embodiment, data stored in the previous patient database 140 are images relating to previous patients, and feature vectors may be computed at this stage of the exemplary method. In this step, the similarity search engine 130 compares the current patient's feature vector to a feature vector relating to each of a plurality of prior patients; comparison proceeds using known metrics, which may include an Lp-norm of the vector difference (e.g., city block distance, Mahalanobis distance, Euclidean distance, and higher order extensions). The result of this comparison is a numerical value describing the similarity of each of the previous patients being evaluated to the current patient. For example, this may be a number on a scale of 0 to 100, 0 to 1, etc.
[0016] Alternatively, rather than performing feature extraction, the images of the current patient and the prior patient are directly geometrically compared. As one example, this involves the use of a translation and rotation invariant Hausdorff distance metric. In another example, this involves the alignment of images to a common atlas by non-rigid registration, and comparison on a voxel-by-voxel basis. The comparison may be applied to each structure in the image (e.g., target volume, organ at risk, etc.), to one or more points contained within the structure (e.g., the centroid of each structure), to the boundaries of each structure, or to the combination of all structures at once. Those of skill in the art will understand that an embodiment that does not involve the comparison of feature vectors may lack the feature extraction step 220 described above. As above, the result of this comparison is a similarity score, and may be, for example, a number on a scale of 0 to 100, 0 to 1, etc.
[0017] As a further example, the comparison step 230 can involve both the comparison of patients as represented by feature vectors, and the comparison of the images as a whole. In this example, the two similarity scores are combined (e.g., by using the mean of the two similarity scores relating to each prior patient, or using another method).
[0018] As a further option, additional features not computed from the images can be included in the feature comparison process, described above. These features may include biomarker data, data relating to family history (e.g., the presence of genes that may indicate increased susceptibility to radiation), age of the patient, history of prior cancer in the patient or the patient's family, presence of other ongoing therapies (e.g., chemotherapy), etc. In such case, these are simply included in the application of the feature comparison engine, without significantly changing the nature of the process described above.
[0019] After comparison of the current patient to prior patients, as described above, in step 240 the prior patients are sorted by their corresponding similarity scores. Next, in step 250 , an initial plan is generated for the current patient by the plan generation system 150 . In a first example, the plan generation system 150 copies the plan from the previous patient with the highest similarity score for use with the current patient. As described above, a plan may include the modality of radiation (e.g., photon, electron, proton), the number of beams/sources, the angular orientation of the beams, the isocenter position within the patient for each beam, the energy of each beam, the use of modifiers (e.g., wedges, dynamic wedges, filters), and the intensity maps. This then becomes the initial plan for the current patient, and may be refined as described above.
[0020] In another alternative example, the plan generation system 150 combines the plans from multiple previous patients. In such an example, one or more of the plan elements (e.g., modality, number of beams, etc.) for the plan for the current patient are generated by combining values from one or more of the previous patients. For example, an angular orientation of one or more of the beams is taken from a weighted average of a group of prior similar patients, with each prior patient weighted by their similarity score to the current patient. In another example, the combination is based on majority votes or on median values. The number of prior patients to be composited and the selection of features to be composited may vary among different implementations; in one example, the planner selects these options.
[0021] In another alternative example, the selection of past patients is filtered based on outcomes; for example, only patients with good clinical outcomes are used. In such an example, the previous patient database 140 additionally stores data relating to outcomes. Outcomes may be quantified as years of survival, years of disease-free survival, time to progression, etc. In another example, the plan generation system 150 also copies dose constraints from prior patients, either by using a dose constraint from a most similar prior patient or using a composite of a plurality of prior patients as described above.
[0022] Finally, in step 260 , the plan that has been generated by the plan generation system 150 is transmitted to the treatment planning workstation 110 . At this point, refinement of this automatically generated initial treatment plan proceeds as usual.
[0023] FIG. 3 illustrates an exemplary display 300 that is provided to a planner using the treatment planning workstation 110 . The display 300 includes an illustration of the geometric features of the current patient. The display 300 also includes an illustration of geometric features of previous patients ranked by similarity. The planner may select one of the previous patients for further viewing, and the display 300 further shows the stored radiation treatment plan for the selected one of the previous patients. For example, in the illustrated display 300 , the most similar previous patient is selected for display.
[0024] The exemplary embodiments result in the generation of an initial radiation treatment plan for the current patient that is of a greater quality than one that is created by the planner on an ad hoc basis based on the planner's own experience. Further, because of the objective nature of the comparison to past patients, the quality of care received by patients may be standardized, rather then dependent upon the skills and experience of the planner. Additionally, because the initial plan for the current patient is based on one or more previous patients sharing characteristics with the current patient, less refinement may be required, resulting in the patient being subjected to less radiation overall and completing the course of radiation treatment sooner.
[0025] Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any number of manners, including, as a separate software module, as a combination of hardware and software, etc. For example, the similarity search engine 130 may be a program containing lines of code that, when compiled, may be executed on a processor.
[0026] It is noted that the claims may include reference signs/numerals in accordance with PCT Rule 6.2(b). However, the present claims should not be considered to be limited to the exemplary embodiments corresponding to the reference signs/numerals.
[0027] It will be apparent to those skilled in the art that various modifications may be made in the present invention, without departing from the spirit or the scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A non-transitory computer-readable storage medium storing a set of instructions executable by a processor. The set of instructions is operable to receive a current patient medical image of a current patient, compare the current patient medical image to a plurality of previous patient medical images, each of the previous patient medical images corresponding to a previous patient, select one of the previous patients based on a geometric similarity between the previous patient medical image of the selected one of the previous patients and the current patient medical image, and determine an initial radiation treatment plan based on a radiation treatment plan of the selected one of the previous patients.
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MICROFICHE APPENDIX
This patent application includes a microfiche appendix consisting of three sheets of microfiche with a total number of 175 frames. This microfiche appendix contains the source code for the software incorporated into this invention.
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
References
These publications are cited hereinabove and they are incorporated by reference:
1. Benner, T. I., Brenner, C. J., Neufeld, B. R., and Britten, R. J. "Reduction in the Rate of DNA Reassociation by Sequence Divergence," 81 Journal of Molecular Biology 123 (1973).
2. Bolton, E. T. and McCarthy, B. J., "A General Method for the Isolation of RNA Complementary to DNA," 48 Proceedings of the National Academy of Science 1390 (1962).
3. Grossi, R. and Luccio, F., "Simple and Efficient String Matching with k Mismatches", 33 Information Processing Letters 113 (Nov. 30, 1989).
4. Hume, A. and Sunday, D., "Fast String Searching," 21(11) Sofware--Practice and Experience 1221 (1991).
5. Itakura, K., Rossi, J. J., and Wallace, R. B., "Synthesis and Use of Synthetic Oligonnucleotides," 53 Annual Review of Biochemistry 323 (1984).
6. Landau, G. M. and Vishkin, U. "Efficient String Matching with k Mismatches," 43 Theoretical Computer Science 239 (1986).
7. Landau, G. M., Vishkin, U., and Nussinov, R., "Alignments with k Differences for Nucleotide and Amino Acid Sequences," 4 CABIOS 19 (1988).
8. Landau, G. M., Vishkin, U., and Nussinov, R., "Fast Alignment of DNA and Protein Sequences," 183 Methods in Enzymology 487 (1990).
9. Lewis, R. M., "PROBFIND: A Computer Program for Selecting Oligonucleotide Probes from Peptide Sequences," 14 NUCLEIC ACIDS RES. 567 (1986).
10. Martin, F. H. and Castro, M. M., "Base Pairing Involving Deoxyinosine: Implications for Probe Design," 13 NUCLEIC ACIDS RES. 8927 (1985).
11. Raupach, R. E., "Computer Programs Used to Aid in the Selection of DNA Hybidization Probes," 12 NUCLEIC ACIDS RES. 833 (1984).
12. Rosenberg, J. M., DICTIONARY OF COMPUTERS, DATA PROCESSING AND TELECOMMUNICATIONS (1984).
13. Southern, E. M., "Detection of Specific Sequences Among DNA Fragments Separated by Gel Electrophoresis," 98 JOURNAL OF MOLECULAR BIOLOGY 503 (1975).
14. Ukkonen, E., "Approximate String-Matching with q:Grams and Maximal Matches," 92 Theoretical Computer Science 191 (1992).
15. von Heijne, G., Sequence Analysis in Molecular Biology (1987) (available at the University of California at Los Angeles and California State University at Northridge).
16. Yang, J., Ye, J., and Wallace, D. C., "Computer Selection of Oligonucleotide Probes from Amino Acid Sequences for Use in Gene Library Screening," 12 Nucleic Acids Res. 837 (1984).
BACKGROUND OF THE INVENTION
This invention relates to the fields of genetic engineering, microbiology, and computer science, and more specifically to an invention that helps the user, whether they be a molecular biologist or a clinical diagnostician, to calculate and design extremely accurate oligonucleotide probes for DNA and mRNA hybridization procedures. These probes may then be used to test for the presence of precursors of specific proteins in living tissues. The oligonucleotide probes designed with this invention may be used for medical diagnostic kits, DNA identification, and potentially continuous monitoring of metabolic processes in human beings. The present implementation of this computerized design tool runs under Microsoft® Windows™ v. 3.1 (made by Microsoft Corporation of Redmond, Wash.) on IBM® compatible personal computers (PC's).
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned hereunder are incorporated herein by reference.
To isolate a specific gene for any particular purpose, a researcher first has to have some idea of what he or she is looking for. To do this, the researcher needs to have a probe, which acts like a molecular hook that can identify and latch onto (i.e., bind to or hybridize with) the desired gene in a crowd of many other genes. A researcher who can obtain an entire strand of mRNA can eventually find the gene from which it was copied, using complementary DNA (cDNA, which is a cloned equivalent to RNA and somewhat equivalent to mRNA) as a probe to search through the great mass of genetic material and locate the desired original gene. cDNA essentially is manufactured or non-naturally occurring DNA from which all of the nonessential DNA has been removed. cDNA allows the researcher to concentrate entirely on the important portions of the gene being examined. The nonessential DNA regions are easy to recognize because when the gene is translated into protein, these regions do not wind up reflected in the protein sequence. These regions are called introns, or intervening regions. mRNA has no introns because they have been "spliced" out of the mRNA before translation. Thus, mRNA and cDNA contain only the essential information from a gene (called the exons). cDNA is the equivalent of mRNA with a complementary sequence, only the exons are present. cDNA may be produced by reverse transcription of mRNA.
The procedure of using cDNA from known mRNA as a probe to search through genetic material and locate the original gene is called molecular hybridization, and is currently one method of identifying specific genes. However, this method is less than perfect, can be extremely time consuming, and often is not even feasible because the researcher actually has to have an entire strand of cDNA from the desired gene before he or she can attempt to use this cDNA to locate and identify the particular gene. Thus, it is something of a circular problem. If the researcher cannot obtain an entire strand of mRNA or cDNA from the desired gene, then he or she must somehow design a probe from scratch to be used to identify that gene.
Oligonucleotide probes (that is, probes made up of a small number of nucleotides, such as 17 to 100), are increasingly being used to identify specific genes from genomic or cDNA libraries when the partial amino acid sequences is known. (von Heijne 1987, Ref. 15). This is a second method of determining a proper probe. Although the present implementation of this invention does not deal with cases in which the proteins have been sequenced, but rather only the DNA or mRNA, it is possible that this invention or a future implementation of it might be used with protein sequences. Such probes can also be used as primers which, when annealed to mRNAs, can be selectively extended into cDNAs. (von Heijne 1987, Ref. 15).
Because of these situations, the problem that the researcher faces is to discover or design a probe or mixture of probes that maximizes the researchers chances of successful hybridization while at the same time minimizing the amount of time and money that has to be spent on discovering or designing the probes. (von Heijne 1987, Ref. 15). Researchers in the field have determined that computer analysis can greatly expedite and simplify the search for optimal probe sequences. (von Heijne 1987, Ref. 15). However, all of the search strategies known to the present inventors are time consuming (both CPU and user time) and may be somewhat inaccurate. As stated in von Heijne, "a true optimization of the probe in terms not only of degeneracy but in terms of length, codon usage, Guanine-Cytosine (GC) avoidance, and expected signal-to-noise ratio (hybridization to target over background) is a fairly complex problem, however, and does not seem to have been automated so far." (von Heijne 1987, Ref. 15). Various search strategies known and used in the field to identify and design probes are outlined in the following sources: Lewis (1986, Ref. 9), Raupach (1984, Ref. 11), Yang et al. (1984, Ref. 16), and Martin and Castro (1984, Ref. 10).
In the simplest version of a protein-related search strategy, the search procedure is limited to finding a set of probes of given lengths with the least possible degeneracy simply by scanning the amino acid sequence and noting the number of alternative codons in the corresponding oligonucleotide as the scan moves along the chain of nucleotides. (Lewis 1986). The researcher can also include codon usage statistics (because more than one codon can translate to the same amino acid), which would attach a probability-of-occurrence value to each probe. (Raupach 1984, Ref. 11).
A more advanced algorithm would allow the researcher to specify the way in which he or she plans to synthesize the probes (for example, by adding toohomers or mixtures of monomers). It would also be easy for a researcher to add a rough estimate of the disassociation (or melting) temperatures of each probe to a program such as this.
One way to solve the problem of finding local similarities between two proteins being compared that has been discussed in the relevant literature is to use list-sorting or hashing routines. (von Heijne 1987, Ref. 15). These routines are based on the construction of a list or lookup table of k-letter words or k-tuples (i.e., all possible di- or trinucleotides), and the positions where they appear in the sequences being compared. This method is employed in some of the most extensively used "fast search" programs (see examples identified in von Heijne 1987, Ref. 15).
Two general methods of designing probes are common in the field, depending upon whether the researcher is trying to design a common probe or a specific probe. Common probes attempt to find common or consensus sequences among various species and among family genes. The first step in designing such a probe is to find the genes of interest. This may be done by performing a keyword or homology search against the GenBank (a genome database available from IntelliGenics of Mountain View, Calif.) or a keyword search against MEDLINE (the database currently available from the U.S. National Library of Medicine under the data access system known as Dialog of Dialog Information Service, Inc., Palo Alto, Calif.) or by performing a homology analysis between one of the genes of interest and whole GenBank sequences. The next step is to retrieve all of the relevant genes of interest. In the third step, multiple alignment analysis can be done using a commercially available software package such as DNASIS (from Hitachi Software of Brisbane, Calif.), which is an autoconnect program. In this step, the computer identifies which nucleotides are common among the requested sequences: ##STR1## Alternatively, after homology analyses between two sequences are carried out, data from the multiple homology analyses can be combined. The researcher then manually has to find the common or consensus region: ##STR2##
Next, the researcher would input the sequence of the common region into the program and then analyze the secondary structure (i.e., the stacking site and the hairpin structure). After this, the researcher manually would select several candidate probes (from five to ten) which contain the minimal hairpin structure and specific length according to the user's interest. A hairpin is an area in which a probe has "folded back" and one portion of the probe has hybridized with another portion of the same probe. The researcher would then perform a homology analysis between each candidate probe and all sequences in the GenBank to find all possible cross-hybridizable genes. Lastly, the researcher manually would decide which is the best candidate probe by determining which probe is highly homologous among the group of interest, but quite different from other unrelated sequences in the GenBank.
The conventional methods for designing common oligonucleotide probes using currently available computer software have at least five problems: (1) they involve time consuming multiple processes; (2) it is difficult to control a significant variable, the melting temperature Tm of the oligonucleotide probes; (3) the methods do not recognize exons and introns and differentiate (thereby making it possible to have a designed probe that is identical to unrelated mRNA sequences); (4) the methods may miss short pieces of identical sequences; and (5) it is difficult to recognize multiple pieces of identical sequences in the gene.
The second method of designing probes that is common in the field involves designing specific probes. Specific probes attempt to find unique sequences among various species and among family genes and among published sequences in the GenBank. A specific probe is a probe that hybridizes with only one particular gene, thereby identifying the presence of that gene for the researcher. The procedure involves first finding the genes of interest (by performing a keyword search against the GenBank or against MEDLINE) and then retrieving all of the relevant genes of interest. A manual homology analysis between the gene of interest and whole sequences in the GenBank can be performed to find common and unique regions. ##STR3##
Next, the researcher would input the sequence of the unique region into the program and then analyze the secondary structure. After this, the researcher would manually select several candidate probes which contain the minimal hairpin structure and specific length according to the user's interest. The researcher would then perform a homology analysis between each candidate probe and all sequences in the GenBank to find all possible cross-hybridizable genes. Lastly, the researcher manually would decide which is the best candidate probe by determining which probe does not have identical sequences in unrelated sequences in the GenBank.
All of the conventional methods for designing specific oligonucleotide probes known to the inventors using currently available computer software have at least four problems: (1) they involve time consuming multiple processes; (2) it is difficult to control the melting temperature Tm of the oligonucleotide probes; (3) the methods do not allow for quantification of uniqueness; and (4) there is no guarantee that the method will design the best possible probe.
None of the methods discussed in the literature discloses a system that may be used to design both common probes and extremely specific probes, especially a method that minimizes user and CPU time and is exceptionally accurate.
Programs currently used for rapid database similarity searches use either hashing strategies or statistical strategies. The hashing strategy is now being used for the detection of relatively short regions of similarity, while the statistical strategy is now being used for the detection of weaker and longer similarity regions. The Mismatch Model of this invention can be used for very strong similarity searches with running times faster than current hashing strategies.
The basic technologies behind the Mismatch Model used in this invention are hashing and continuous seed filtration, each general technology being known in the public domain and having been previously applied separately to non-genetic applications. To the best of the inventors' knowledge, these methods, used together, have never been suggested in other studies on optimal probe selection. The inventors' methods have a program performance of tens of seconds (CPU+I/O time) with a 1000 nucleotide query and all mammalian DNA on a SPARC station, and are even faster on the more common personal computer proposed herein.
The H-Site Model of this invention likewise is unique in that it offers a multitude of information on selected probes and original and distinctive means of visualizing, analyzing and selecting among candidate probes designed with the invention. Candidate probes are analyzed using the H-Site Model for their binding specificity relative to some known set of mRNA or DNA sequences, collected in a database such as the GenBank database. The first step involves selection of candidate probes at some or all the positions along a given target. Next, a melting temperature model is selected, and an accounting is made of how many false hybridizations each candidate probe will produce and what the melting temperature of each will be. Lastly, the results are presented to the researcher along with a unique set of tools for visualizing, analyzing and selecting among the candidate probes.
This invention is both much faster and much more accurate than the methods that are currently in use. It is unique because it is the only method that can find not only the most specific and unique sequence, but also the common sequences. Further, it allows the user to perform many types of analysis on the candidate probes, in addition to comparing those probes in various ways to the target sequences and to each other.
Therefore, it is the object of this invention to provide a practical and user-friendly system that will allow a researcher to design both specific and common oligonucleotide probes, and to do this in less time and with much more accuracy than currently done. For example, the current version of the GenBank contains over ninety (90) million nucleotides. It is thought that the human genome alone consists of three billion base pairs, and scientists have so far managed to decode the base sequence of only about 500 human genes, less than one percent of the total. Currently available searching strategies are limited in how many of the GenBank's sequences can be accessed and successfully searched, and how convenient and feasible such a search would be (in terms of both computer processor and human user time). It is also an object of this invention to allow the user to be able to run the program on more readily available and far less expensive computer hardware (i.e., a PC rather than a mainframe). This invention will remove those limits and allow genetic research to take a giant leap forward.
These and other advantages and objects of this invention will become apparent from the following detailed descriptions, drawings, and appended claims.
BRIEF DESCRIPTION OF THE INVENTION
There is disclosed herein a system which allows the user to calculate and design extremely accurate oligonucleotide probes for DNA and mRNA hybridization procedures. The invention runs under Microsoft® Windows on IBM® compatible personal computers (PC's). Its key features design oligonucleotide probes based on the GenBank database of DNA and mRNA sequences and examine probes for specificity or commonality with respect to a user-selected experimental preparation of gene sequences. Hybridization strength between a probe and a subsequence of DNA or mRNA can be estimated through a hybridization strength model. Quantitatively, hybridization strength is given as the melting temperature Tm. Currently, two hybridization strength models are supported by this invention: 1) the Mismatch Model and 2) the H-Site Model. The user is allowed to select from the following calculations for each probe, results of which are available for display and analysis: 1) Sequence, Melting Temperature (Tm) and Hairpin characteristics; 2) Hybridization with other species within the preparation mixture; and (3) Location and Tm for the strongest hybridizations. The results of the invention's calculations are then displayed on the Mitsuhashi Probe Selection Diagram (MPSD), which is a graphic display of all of the hybridizations of probes for the target mRNA with all sequences in the preparation.
The Main Dialog Window of the present implementation of this invention controls all user-definable settings. The user is offered a number of options at this window. The File option allows the user to print, print in color, save selected probes, and exit the program. The Preparation option allows the user to open and create preparation (PRP) files. The Models option allows the user to chose between the two hybridization models currently supported by the invention: 1) the H-Site Model and 2) the Mismatch Model. If the user selects the H-Site Model option, the user normally sets the following model parameters: 1) the melting temperature Tm for which probes are being designed (i.e., the melting temperature that corresponds to a particular experiment or condition the user desires to simulate); and 2) the nucleation threshold, which is the number of base pairs constituting a nucleation site. If the user selects the Mismatch Model option, the user normally sets the following model parameters: 1) probe length, which is the number of bases in probes to be considered; and 2) mismatch N, which is the maximum number of mismatches constituting a hybridization.
The Mismatch Model program is used to design DNA and mRNA probes, utilizing sequence database information from sources such as GenBank and other databases with similar file formats. In the Mismatch Model, hybridization strength is related only to the number of base pair mismatches between a probe and its binding site. Generally, the more mismatches a user allows, the more probes will be found. The Mismatch Model does not take into account the Guanine-Cytosine (GC) content of candidate probes, as does the H-Site Model, discussed below, so there is no reflection or indication of the probe's binding strength. The basic technologies employed by this model are hashing and continuous seed filtration. Hashing involves the application of an algorithm or process to the records in a set of data to obtain a symmetric grouping of the records. When using an indexed set of data, hashing is the process of transforming a record key to an index value for storing and retrieving a record. Rosenberg (1984, Ref. 12)). The concept of continuous seed filtration is discussed in detail below.
The essence of the Mismatch Model is a fast process for doing exact and inexact matching between DNA and mRNA sequences to support the Mitsuhashi Probe Selection Diagram (MPSD) and other types of analysis discussed above. The process used by the Mismatch Model is the Waterman-Pevzner Algorithm (the WPALG, which is named for two of the inventors), which is a computer-based probe selection process. Essentially, this is a combination of new and improved pattern matching processes. See Hume and Sunday (1991, Ref. 4), Landau et al (1986-1990, Refs. 6, 7, 8), Grossi and Luccio (1989, Ref. 3), and Ukkonen (1982, Ref. 14).
There are three principal programs that make up the Mismatch Model in this implementation of the invention. The first is designated by the inventors as "k -- diff." WPALG is used in k -- diff to find all locations of matches of length greater than or equal to one (1) (length is user-specified) with less than or equal to k number of mismatches (k is also user-specified) between the two sequences. If a candidate oligonucleotide probe fails to match that well, it is considered unique. k -- diff uses hashing and continuous seed filtration, and looks for homologs in GenBank and other databases with similar file formats. The technique of continuous seed filtration allows for much more efficient searching than previously implemented techniques. A seed is defined in this invention to be a subsequence of length equal to the longest exact match in the worst case scenario. For example, suppose the user selects a probe length (1) of 18, with 2 or fewer mismatches (k). If a match exists with 2 mismatches, then there must be a perfectly matching subsequence of length equal to 6. Once the seed length has been determined, the Mismatch Model looks at all substrings of that seed length (in this example, that seed length would be 6), finds the perfectly matched base pair subsequence of length equals 6, and then looks to see if this subsequence extends to a sequence of length equal to the user selected probe length (i.e., 20 in this example). If so, a candidate probe has been found that meets the user's criteria.
Where the seed size is large, the program allocates a relatively large amount of memory for the hash table. This invention has an option that allows memory allocation for GenBank entries just once at the beginning of the program, instead of reallocating memory for each GenBank entry. This reduces input time for GenBank entries by as much as a factor of two (2), but the user needs to know the maximum GenBank entry size in advance to do this.
A probe is defined to hybridize if it has k or fewer mismatches in comparison with a target sequence from the database or file searched. Otherwise, it is non-hybridizing. The hit extension time for all appropriate parameters of the Mismatch Model has been found by experimentation to be less than thirty-five (35) seconds, except in one case where the minimum probe length (1) was set to 24 and the maximum number of mismatches (k) was set to four (4), which is a situation that is never used in real gene localization experiments because the hybridization conditions are too weak.
In this invention, the second hybridization strength model is termed the H-Site Model. One aspect of the H-Site Model uses a generalization of an experimental formula in general usage. The basic formula on which this aspect of the model is built is as follows:
Tm=81.5-16.6(log[Na]) -0.63 %(formamide) +0.41 (%(G+C)) -600 / N In this formula, log[Na] is the sodium concentration, %(G+C) is the fraction of matched base pairs which are G-C complementary, and N is the probe length. In other words, this formula is an expression of the fact that melting temperature Tm is a function of both probe length and percent of Guanine-Cytosine (GC) content. This basic formula has been modified in this invention to account for the presence of mismatches. Each percent of mismatch reduces the melting temperature Tm by an average of 1.25 degrees (2 degrees C. for an Adenine-Thymine mismatch, and 4 degrees C. for a Guanine-Cytosine mismatch). This formula is, however, an approximation. The actual melting temperature might differ significantly from this approximation, especially for short probes or for probes with a relatively large number of mismatches.
Hybridization strength in the H-Site Model is related to each of the following factors: 1) "binding region"; 2) type of mismatch (GC or AT substitution); 3) length of the probe; 4) GC content of the binding region (since GC pairs have a stronger bond than AT pairs, thus requiring a higher melting temperature); and 5) existence of a "nucleation site" (an exactly matching subsequence). The type of mismatch and the GC content of the binding region each contribute to a candidate probe's binding strength, which can be compared to other candidate probes' binding strengths to enable the user to select the optimal probe.
The fundamental assumption of the H-Site Model is that binding strength is determined by a paired subsequence of the probe-species combination, called the binding region. If the binding region contains more GC pairs than AT pairs, the binding strength will be higher since the G and. C bases (connected with three bonds) form a tighter bond than the A and T bases (connected with two bonds). Thus, G and C bases, and probes that are GC rich, require a higher melting temperature Tm and subsequently form a stronger bond. In the H-Site Model, and one of its unique features, the program designs optimal probes, ideally ones that do not have any mismatches, but if there are mismatches the H-Site Model takes these into account. With this model, a candidate probe can afford to have more mismatches involving the AT bases if there are more GC bases than AT bases in the probe. This is because this model looks primarily at regions of the candidate probe and target sequence that match and does not "penalize" the probe for areas that do not match. If the mismatches are located at either or both of the ends of the binding region, this has little effect. It is much more deleterious to have mismatches in the middle of the binding region, as this will significantly lower the binding strength of the probe.
The formula cited above for Tm applies within the binding region. The length of the probe is used to calculate percentages, but all other parameters of the formula are applied to the binding region only. The H-Site Model further assumes the existence of a nucleation site, which is a region of exact match. The length of this nucleation site may be set by the user. Typically, a value of 8 to 10 base pairs is used. To complete the H-Site Model, the binding region is chosen so as to maximize the melting temperature Tm among all regions containing a nucleation site, assuming one exists (otherwise, Tm=0).
The H-Site Model is more complex than the Mismatch Model discussed above in that hybridization strength is modeled as a sum of signed contributions, with matches generally providing positive binding energy and mismatches generally providing negative binding energy. The exact coefficients to be used depend only on the matched or mismatched pair. These coefficients may be specified by the user, although in the current version of this invention these coefficients are not explicitly user-selectable, but rather are selected to best fit the hybridization strength formulas developed by Itakura et al (1984, Ref. 5), Bolton and McCarthy (1962, Ref. 2), Benner et al (1973, Ref. 1), and Southern (1975, Ref. 13).
A unique aspect of the H-Site Model is that hybridization strength is defined to be determined by whatever the optimal binding region between the candidate probe and binding locus. This binding region is called the hybridization site, or h-site, and is selected so as to maximize overall hybridization strength, so that mismatches outside the binding region do not detract from the estimated hybridization strength. Several other unique features of the H-Site Model include the fact that it is more oriented toward RNA and especially cDNA sequences than DNA sequences, and the fact that the user has control over preparation and environmental variables. The first feature allows the user to concentrate on "meaningful" sequences, rather than having to sort through all of a DNA sequence (including the introns). The second feature allows the user to more accurately simulate laboratory conditions and more closely correspond with any experiments he or she is conducting. Further, this implementation of the invention does some preliminary preprocessing of the GenBank database to sort out and select the cDNA sequences. This is done by locating a keyword (in this case CDS) in each GenBank record, thereby eliminating any sequences containing introns.
The Mitsuhashi Probe Selection Diagram (MPSD), FIG. 4, is the third key feature of this invention, as it is a unique way of visualizing the results of the probe designing performed by the Mismatch and H-Site Models. It is a graphic display of all of the hybridizations of candidate oligonucleotide probes for the target mRNA with all sequences in the preparation. Given a gene sequence database and a target mRNA sequence, the MPSD graphically displays all of the candidate probes and their hybridization strengths with all sequences from the database. In the present implementation, each melting temperature Tm is displayed as a different color, from red (highest Tm) to blue (lowest Tm). The MPSD allows the user to see visually the number of false hybridizations at various temperatures for all candidate probes, and the sources of these false hybridizations (with a loci and sequence comparison). A locus may be a specific site or place, or, in the genetic sense, a locus is any of the homologous parts of a pair of chromosomes that may be occupied by allelic genes.
BRIEF DESCRIPTION OF THE DRAWING
This invention may be more clearly understood from the following detailed description and by reference to the drawing in which:
FIG. 1 is a simplified block diagram of a computer system illustrating the overall design of this invention;
FIG. 2 is a display screen representation of the main dialog window of this invention;
FIG. 3 is a flow chart of the overall invention illustrating the program, and the invention's sequence and structure;
FIG. 4 is a display screen representation of the Mitsuhashi probe selection diagram;
FIG. 5 is a display screen representation of the probeinfo and matchinfo window;
FIG. 6 is a display screen representation of the probesedit window;
FIG. 6a is a printout of the probesedit output file;
FIG. 7 is a flow chart of the overall k -- diff program of the Mismatch Model of this invention, including its sequence and structure;
FIG. 8 is a flow chart of the k -- diff module of this invention;
FIG. 9 is a flow chart of the hashing module of this invention;
FIG. 10 is a flow chart of the tran module of this invention;
FIG. 11 is a flow chart of the let -- dig module of this invention;
FIG. 12 is a flow chart of the update module of this invention;
FIG. 13 is a flow chart of the assembly module of this invention;
FIG. 14 is a flow chart of the seqload module of this invention;
FIG. 15 is a flow chart of the read 1 module of this invention;
FIG. 16 is a flow chart of the dig -- let module of this invention;
FIG. 17 is a flow chart of the q -- colour module of this invention;
FIG. 18 is a flow chart of the hit -- ext module of this invention;
FIG. 19 is a flow chart of the colour module of this invention;
FIG. 20 is a printout of a sample file containing the output of the Mismatch Model program of this invention;
FIG. 21 is a flow chart of the H-Site Model, stage I, covering the creation of a preprocessed preparation file of this invention;
FIG. 22 is a flow chart of the H-Site Model, stage II, covering the preparation of the target sequence(s);
FIG. 23 is a flow chart of the H-Site Model, stage III, covering the calculation of MPSD data;
FIG. 24a is a printout of a sample file containing output of the Mismatch Model program;
FIG. 24b is a printout of a sample file containing output of the H-Site Model program;
FIG. 25 is a flow chart of the processing used to create the Mitsuhashi probe selection diagram (MPSD);
FIG. 26 is a flow chart of processing used to create the matchinfo window;
FIG. 27 is a printout of a sample target species file;
FIG. 28 is a printout of a sample preparation file.
DETAILED DESCRIPTION OF THE INVENTION
This invention is employed in the form best seen in FIG. 1. There, the combination of this invention consists of an IBM® compatible personal computer (PC), running software specific to this invention, and having access to a distributed database with the file formats found in the GenBank database and other related databases.
The preferred computer hardware capable of operating this invention involves of a system with at least the following specifications (FIG. 1): 1) an IBM® compatible PC, generally designated 1A, 1B, and 1C, with an 80486 coprocessor, running at 33 Mhz or faster; 2) 8 or more MB of RAM, 1A; 3) a hard disk 1B with at least 200 MB of storage space, but preferably 1 GB; 4) a VGA color monitor 1C with graphics capabilities of a size sufficient to display the invention's output in readable format, preferably with a resolution of 1024×768; and 5) a 580 MB CD ROM drive 5 (1B of FIG. 1 generally refers to the internal storage systems included in this PC, clockwise from upper right, two floppy drives, and a hard disk). Because the software of this invention preferably has a Microsoft® Windows™ interface, the user will also need a mouse 2, or some other type of pointing device.
The preferred embodiment of this invention would also include a laser printer 3 and/or a color plotter 4. The invention may also require a modem (which can be internal or external) if the user does not have access to the CD ROM versions of the GenBank database 8 (containing a variable number of gene sequences 6). If a modem is used, information and instructions are transmitted via telephone lines to and from the GenBank database 8. If a CD ROM drive 5 is used, the GenBank database (or specific portions of it) is stored on a number of CDs.
The computer system should have at least the Microsoft® DOS v. 5.0 operating system running Microsoft® Windows™ v. 3.1. All of the programs in the preferred embodiment of the invention are written in the Borland® C++ (made by Borland International, Inc., of Scotts Valley, Calif.) computer language. It must be recognized that subsequently developed computers, storage systems, and languages may be adapted to utilize this invention and vice versa.
This invention is designed to enable the user to access DNA, mRNA and cDNA sequences stored either in the GenBank or in databases with similar file formats. GenBank is a distributed flat file database made up of records, each record containing a variable number of fields in ASCII file format. The stored database itself is distributed, and there is no one database management system (DBMS) common to even a majority of its users. One general format, called the line type format, is used both for the distributed database and for all of GenBank's internal record keeping. All data and system files and indexes for GenBank are kept in text files in this line type format.
The primary GenBank database is currently distributed in a multitude of files or divisions, each of which represents the genome of a particular species (or at least as much of it as is currently known and sequenced and publicly available). The GenBank provides a collection of nucleotide sequences as well as relevant bibliographic and biological annotation. Release 72.0 (Jun. 6/1992) of the GenBank CD distribution contains over 71,000 loci with a total of over ninety-two (92) million nucleotides. GenBank is distributed by IntelliGenetics, of Mountain View, Calif., in cooperation with the National Center for Biotechnology Information, National Library of Medecinge, in Bethesda, Md.
1. Overall Description of the Invention
a. General Theory
The intent of this invention is to provide one or more fast processes for performing exact and inexact matching between DNA sequences to support the Mitsuhashi Probe Selection Diagram (MPSD), discussed below, and other analysis with interactive graphical analysis tools. Hybridization strength between a candidate oligonucleotide probe and a subsequence of DNA, mRNA or cDNA can be estimated through a hybridization strength model. Quantitatively, hybridization strength is given as the melting temperature Tm. Currently, two hybridization strength models are supported by the invention: 1) the Mismatch Model and 2) the H-Site Model.
b. Inputs
i. Main Dialog Window
The Main Dialog Window, FIG. 2, controls all user-definable settings. This window has a menu bar offering five options: 1) File 10; 2) Preparation 30; 3) Models 20; 4) Experiment 40; and 5) Help 50. The File 10 option allows the user to print, print in color, save selected probes, and exit the program. The Preparation 30 option allows the user to open and create preparation (PRP) files.
The Models 20 option allows the user to chose between the two hybridization models currently supported by the invention: 1) the H-Site Model 21 and 2) the Mismatch Model 25. If the user selects the H-Site Model 21 option, the left hand menu of FIG. 2C is displayed and the user sets the following model parameters: 1) the meeting temperature Tm 22 for which probes are being designed (i.e., the melting temperature that corresponds to a particular experiment or condition the user desires to simulate); and 2) the nucleation threshold 23, which is the number of base pairs constituting a nucleation site. If the user selects the Mismatch Model 25 option, the right hand menu of FIG. 2C is displayed and the user sets the following model parameters: 1) probe length 26, which is the number of base pairs in probes to be considered; and 2) mismatch N 27, which is the maximum number of mismatches constituting a hybridization. Computation of the user's request will take longer with the H-Site Model if the threshold 23 setting is decreased and with the Mismatch Model if the number of mismatches K 27 is increased.
In addition, for both Model options the user chooses the target species 11 DNA or mRNA for which probes are being designed and the preparation 12, a file of all sequences with which hybridizations are to be calculated. A sample of a target species file is shown in FIG. 27 (humbjunx.cds), while a sample of a preparation file is shown in FIG. 28 (junmix.seq). Each of these inputs is represented by a file name and extension in general DOS format. In the target species and preparation fields, the file format follows the GenBank format, and each of the fields includes a default file extension. Pressing the "OK" button 41 of FIG. 2C will cause the processing to begin, and pressing the "Cancel" button 43 will cause it to stop.
The Experiment 40 option and the Help 50 option are expansion options not yet available in the current implementation of the invention.
c. Processing
FIG. 3 is a flow chart of the overall program, illustrating its sequence and structure. Generally, the main or "control" program of the invention basically performs overall maintenance and control functions. This program, as illustrated in FIG. 3, accomplishes the general housekeeping functions 51, such as defining global variables. The user-friendly interface 53, carries out the user-input procedures 55, the file 57 or database 59 access procedures, calling of the model program 62 or 63 selected by the user, and the user-selected report 65 or display 67, 69, 71 and 73 features. Each of these features is discussed in more detail in later sections, with the exception of the input procedures, which involves capturing the user's set-up and control inputs.
d. Outputs
i. The Mitsuhashi Probe Selection Diagram Window
The Mitsuhashi Probe Selection Diagram (MPSD), FIG. 4, is a key feature of the invention as it is a unique way of visualizing the results of the program's calculations. It is a graphic display of all of the hybridizations of probes for the target mRNA with all sequences in the preparation. In other words, given a sequence database and a target mRNA, the MPSD graphically displays all of the candidate probes and their hybridization strengths with all sequences from the sequence database. The MPSD allows the user to see visually the number of false hybridizations at various temperatures for all candidate probes, and the sources of these false hybridizations (with a loci and sequence comparison).
For each melting temperature Tm of interest, a graphical representation of the number of hybridizations for each probe is displayed. In the preferred embodiment, this representation is color coded. In this implementation of the invention, the color red 123 identifies the highest melting temperature Tm and the color blue 124 identifies the lowest melting temperature Tm. Each mismatch results in a reduction in Tm. Tm is also a function of probe length and percent content of GC bases. Within the window, the cursor 125 shape is changed from a vertical line bisecting the screen to a small rectangle when the user selects a particular probe. The current probe is defined to be that probe under the cursor position (whether it be a line or a rectangle) in the MPSD window. More detailed information about the current probe is given in the ProbeInfo and MatchInfo windows, discussed below. Clicking the mouse 2 once at the cursor 125 selects the current probe. Clicking the mouse 2 a second time deselects the current probe. Moving the cursor across the screen causes the display to change to reflect the candidate probe under the current cursor position.
The x-axis 110 of the MPSD, FIG. 4, shows the candidate probes' starting positions along the given mRNA sequence. The user may "slide" the display to the left or right in order to display other probe starting positions. The y-axis 115 of the MPSD displays the probe specificity, which is calculated by the program.
The menu options 116, 117, 118, 119, and 120 available to the user while in the MPSD, FIG. 4, are displayed along a menu bar at the top of the screen. The user can click the mouse 2 on the preferred option to briefly display the option choices, or can click and hold the mouse button on the option to allow an option to be selected. The user may also type a combination of keystrokes in order to display an option in accordance with well-known computer desk top interface operations. This combination usually involves holding down the ALT key while pressing the key representing the first letter of the desired option (i.e, F, P, M, E or H).
The File option 116 allows the user to specify input files and databases. The Preparation option 117 allows the user to create a preparation file summarizing the sequence database. The Models option 118 allows the user to specify the hybridization model (i.e., H-Site or Mismatch) and its parameters. The Experiment option 119 and the Help option 120 are not available in the current implementation of this invention. These options are part of the original Main Dialog Window, FIG. 2.
Areas on the graphical display of the MPSD, FIG. 4, where the hybridizations for the optimal probes are displayed are lowest and most similar, such as shown at 121, indicate that the particular sequence displayed is common to all sequences. Areas on the graphical display of the MPSD where the hybridizations for the optimal probes are displayed are highest and most dissimilar, such as shown at 122, indicate that the particular sequence displayed is extremely specific to that particular gene fragment. The high points on the MPSD show many loci in the database, to which the candidate probe will hybridize (i.e., many false hybridizations). The low points show few hybridizations, at least relative to the given database. In other words, the sequence shown at 121 would reflect a probe common to all of the gene fragments tested, such that this probe could be used to detect each of these genes. The sequence shown at 122 would reflect a probe specific to the particular gene fragment, such that this probe could be used to detect this particular gene and no others.
ii. The ProbeInfo and MatchInfo Window
The combined ProbeInfo and MatchInfo Window, FIG. 5, displays detailed information about the current candidate probe. The upper portion of the window is the ProbeInfo window, and the lower portion is the MatchInfo window. The ProbeInfo window portion displays the following types of information: the target locus (i.e., the mRNA, cDNA, or DNA from which the user is looking for probes) is displayed at 131, while the preparation used for hybridizations is displayed at 132. In the example shown in FIG. 5, the target locus 131 is the file named HUMBJUNX.CDS, which is shown as being located on drive F in the subdirectory MILAN. The preparation 132 is shown as being the file designated JUNMIX.PRP, which is also shown as being located on drive F in the subdirectory MILAN. The JUNMIX.PRP preparation in this example is a mixture of human and mouse jun loci.
The current and optimal probe's starting position is shown at 135. The current candidate oligonucleotide probe is defined at 136, and is listed at 137 as having a length of 21 bases. The melting temperature for the probe 136 as hybridized with the targets is shown in column 140. The melting temperature for the optimal probe is given as 61.7 degrees C. at 138. The ProbeInfo Window FIG. 5 also displays hairpin characteristics of the probe at 139. In the example shown, the ProbeInfo Window shows that there are four (4) base pairs involved in the worst hairpin, and that the worst hairpin has a length of one (1) (see FIG. 5, at 139).
The MatchInfo Window portion displays a list of hybridizations between the current probe and species within the preparation file, including hybridization loci and hybridization temperatures. The hybridizations are listed in descending order by melting temperature. The display shows the locus with which the hybridization occurs, the position within the locus, and the hybridization sequence.
In the MatchInfo window portion, the candidate probe 136 is shown at 150 as hybridizing completely with a high binding strength. This is because the target DNA is itself represented in the database in this case, so the candidate probe is seen at 150 to hybridize with itself (a perfect hybridization). The locus of each hybridization from the preparation 132 are displayed in column 141, while the starting position of each hybridization is given in column 142. The calculated hybridizations are shown at 145.
iii. The ProbesEdit Window
The ProbesEdit Window, FIG. 6, is a text editing window provided for convenient editing and annotation of the invention's text file output. It is also used to accumulate probes selected from the MPSD, FIG. 4, by mouse 2 clicks. Standard text editing capabilities are available within the ProbesEdit Window. The user may accumulate selected probes in this window (see 155 for an example) and then save them to a file (which will bear the name of the preparation sequence with the file extension of "prb" 156, or may be another file name selected by the user). A sample of this file is shown in FIG. 6A.
iv. Miscellaneous Output
The present embodiment of this invention also creates two output files, currently named "test.out" and "test1.out", depending upon. which model the user has selected. The first file, "test.out", is created with both the Mismatch Model and the H-Site Model. This file is a textual representation of the Mitsuhashi Probe Selection Diagram (MPSD). It breaks the probe sequence down by position, length, delta Tm, screensN, and the actual probe sequence (i.e., nucleotides). An example of this file created by the Mismatch Model is shown in FIG. 20, and example created by the H-Site Model is shown in FIG. 24A. The second file, "test1.out", is created only by the H-Site Model. This file is a textual representation of the ProbeInfo and MatchInfo window that captures all hybridizations, along with their locus, starting position, melting temperature, and possible other hybridizations. A partial example of this file is shown in FIG. 24B (10 pages out of a total of 190 pages created by the H-Site Model).
2. Description of the Mismatch Model Program
a. Overview
In this invention, one of the hybridization strength models is termed the Mismatch Model (see FIG. 2 for selection of this model). The basic operation of this model involves the techniques of hashing and continuous seed filtration, as defined earlier and described in more detail below. The essence of the Mismatch Model is a fast process for doing exact and inexact matching between DNA and mRNA sequences to support the Mitsuhashi Probe Selection Diagram (MPSD). There are a number of modules in the present implementation of the Mismatch Model contained in this invention, the most significant of which are shown in the flow chart in FIG. 7 and in more detail in FIGS. 8 through 18. The main k -- diff module shown in the flow chart in FIG. 8 is a structured program that provides overall control of the Mismatch Model, calling various submodules that perform different functions.
b. Inputs
The user-selected input variables for this model are minimum probe length 26 (which is generally from 18 to 30) and maximum number of mismatches 27 (which generally is from 1 to 5). These inputs are entered by the user in the Main Dialog Window, FIG. 2C.
c. Processing
i. k -- diff Program
Some terms of art need to be defined before the processing performed by this module can be explained. A hash table basically is an array or table of data. A linked list is a classical data structure which is a chain of linked entries and involves pointers to other entry structures. Entries in a linked list do not have to be stored sequentially in memory, as is the case with elements contained in an array. Usually there is a pointer to the list associated with the list, which is often initially set to point to the start of the list. A pointer to a list is useful for sequencing through the entries in the list. A null pointer (i.e., a pointer with a value of zero) is used to mark the end of the list.
As the flow charts in FIGS. 7 and 8 illustrate, the general process steps and implemented functions of this model can be outlined as follows:
Step 1: First, create a hash table and linked list from the query (FIG. 7, hashing module 222).
Step 2: Next, while there are still GenBank entries available for searching (FIG. 7, assembly module 230):
Step 2a: Read the current GenBank entry (record) sequence of user-specified length (FIG. 7, seqload module 232), or read the current sequence (record) from the file selected by the user (FIG. 7, read1 module 234).
Step 2b: For the current sequence for each position of the sequence from the first position (or nucleotide) to the last position (or nucleotide) (incrementing the position number once each iteration of the loop) (FIG. 7, q -- colour module 242),
Step 2c: set the variable dna -- hash equal to the hash of the current position of the current sequence (FIG. 7, q -- colour module 242).
Step 2d: While not at the end of the linked list for dna -- hash (FIG. 7, q -- colour module 242),
Step 2e: set the query -- pos equal to the current position of dna -- hash in the linked list (FIG. 7, q -- colour module 242) and
Step 2f: Extend the hit with the coordinates (query -- pos, dna -- pos) (FIG. 7, hit -- ext module 244),
Step 2g: If there exists a k -- mismatch in the current extended hit (FIG. 7, colour module 246), then
Step 2h: print the current hit (FIG. 7, q -- colour module 242), and repeat from Step 2. As this illustrates, there are three (3) basic looping or iteration processes with functions being performed based on variables such as whether the GenBank section end has been reached (the first "WHILE" loop, Step 2), whether the end of the current DNA entry has been reached (the "FOR" loop, Step 2b), and whether the end of the dna -- hash linked list has been reached (the second "WHILE" loop, Step 2d). A "hit" will only be printed if there are k -- mismatches in the current extended hit.
FIGS. 8 through 18 illustrate the functions of each of the modules of the present embodiment of this invention, all of which were generalized and summarized in the description above. FIG. 8, which outlines the main "k -- diff" module, shows that this module is primarily a program organization and direction module, in addition to performing routine "housekeeping" functions, such as defining the variables and hash tables 251, checking if the user-selected gene sequence file is open 252, extracting needed identification information from the GenBank 253, and ensuring valid user input 254. This module also performs a one-time allocation of memory for the gene sequences, and allocates memory for hit information, hashing, hybridization and frequency length profiles and output displays, 255 & 256. The "k -- diff" module also initializes or "zeros out" the hashing table, the linked hashing list and the various other variables 257 in preparation for the hashing function. In addition, this module forms the hash tables 258 and extracts a sequence and finds the sequence length 259.
One of the most important functions performed by the "k -- diff" module is to define the seed (or kernel or k -- tuple) size. This is done by setting the variable k -- tuple equal to (min.probe -- length-max -- mismatch -- #)/(max -- mismatch+#+1) FIG. 8 at 265. Next, if the remainder of the aforementioned process is not equal to zero 266, then the value of the variable k -- tuple is incremented by one 267. The resulting value is the size of the seed. The module then reads the query 268 and copies the LOCUS name 269 for identification purposes (a definition of the term locus is given earlier in the specification).
The "k -- diff" module FIG. 8 also calls the "assembly" module 260, writes the results to a file 261a, plots the results 261b (discussed below), calculates the hairpin characteristics 262 (i.e., the number of base pairs and the length of the worst hairpin) and the melting temperature (Tm) for each candidate probe 263, and saves the results to a file 264.
The screen graphs are plotted 261b by converting the result values to pixels, filing a pixel array and performing a binary search into the pixel array. Next, given the number of pixels per probe position and which function is of interest to the user (i.e., the three mismatch match numbers), the program interpolates the values at the value of (pixelsPerPositionN-1) and computes the array of pixel values for drawing the graph. These values are then plotted on the MPSD.
The "hashing" module, FIG. 9, performs hashing of the query. In other words, it creates the hash table and linked list of query positions with the same hash. The variable has -- table[i] equals the position of the first occurrence of hash i in the query. If i does not appear in the query, hash -- table[i] is set to zero.
The "tran" module, FIG. 10, is called by the "hashing" module 271, and performs the hashing of the sequence of k -- tuple (kernel or seed) size. If the k -- tuple exists (i.e., its length is greater than zero), the variable uns is set equal to uns*ALF+p 291. The variable p represents the digit returned by the "let -- dig" module FIG. 11 that represents the nucleotide being examined. ALF is a constant that is set by the program in this implementation to equal four. The query pointer is then incremented, while the size of k -- tuple (the seed) is decremented 292. This process is repeated until the sequence of k -- tuple has been entirely hashed. Then the "tran" module returns the variable current -- hash 293 to the "hashing" module FIG. 9.
The "let -- dig" module, FIG. 11, is called by the "tran" module 291, and transforms the nucleotides represented as the characters "A", "T", "U", "G" and "C" in the GenBank and the user's query into numeric digits for easier processing by the program. This module transforms "a" and "A" into "0" 301, "t", "T", "u" and "U" into "1" 302, "g" and "G" into "2" 303, and "c" and "C" into "3" 305. If the character to be transformed does not match any one of those listed above, the module returns "-1" 305. The "hashing" module, FIG. 9, then calls the "update" module 272, FIG. 12, which updates the hash with a sliding window (i.e., it forms a new hash after shifting the old hash by "1"). The remainder of old -- hash divided by power -- 1 is calculated 311 (a modulus operation), the remainder is multiplied by ALF 312 (i.e., four), and then the digit representing the nucleotide is added to the result 313. The "update" module then returns the result 314 to the "hashing" module FIG. 9.
If the current hash has already occurred in the query, the program searches for the end of the linked list for the current hash 273 and marks the end of the linked list for the current hash 274. If the current hash has not already occurred in the query, the program puts the hash into the hash table 275. The resulting hash table and linked list are then returned to the "k -- diff" module, FIG. 8 at 258.
The "assembly" module, FIG. 13, extracts sequences from the GenBank and performs hit locating and extending functions. This module is called by the "k -- diff" module FIG. 8 at 260 if the user has chosen to use the database to locate matches. The output from the "assembly" module (FIG. 13) tells the user that the section of the database searched contains E number of entries 321 of S summary length 322 with H number of hits 323. Further, the program tells the user that the number of considered 1-tuples equals T 324. The entry head line is also printed 326.
The "seqload" module, FIG. 14, is called by the "k -- diff" module FIG. 8 at 259 once the query hash table and linked list have been formed by the "hashing" module FIG. 9. The "seqload" module FIG. 14 checks to see if the end of the GenBank file has been reached 327, and, if not, searches until a record is found with LOCUS in the head-line 328. Next, the LOCUS name is extracted 329 for identification purposes, and the program searches for the ORIGIN field in the record 330.
The program then extracts the current sequence 331 from the GertBank and performs two passes on each sequence. The first is to determine the sequence length 332 and allocate memory for each sequence 333, and the second pass is to read the sequence into the allocated memory 334. Since the sequences being extracted can contain either DNA nucleotides or protein nucleotides, the "seqload" module can recognize the characters "A", "T", "U", "G", and "C". The bases "A", "T", "G" and "C" are used in DNA sequences, while the bases "A", "U", "G" and "C" are used in RNA and mRNA sequences. The extracted sequence is then positioned according to the type of nucleotides contained in the sequence 335, and the process is repeated. Once the end of the sequence has been reached, the "seqload" module returns the sequence length 336 to the "k -- diff" module FIG. 8.
If the user has chosen to use one or more files to locate matches, rather than the database, the "read1" module, FIG. 15, rather than the "seqload" module FIG. 14, is called by the "k -- diff" module FIG. 8. The "read1" module, FIG. 15, reads the sequence from the user specified query file 341 and allocates memory 342. This module also determines the query length 343, extracts sequence identification information 344, determines the sequence length 345, transforms each nucleotide into a digit 346 by calling the "let -- dig" module FIG. 11, creates the query hash table 347 by calling the "dig -- let: module FIG. 16, and closes the file 348 once everything has been read in.
First, the "read1" module FIG. 15 allocates space for the query 342. To do this, the "ckalloc" module, FIG. 15 at 342, is called. This module allocates space and checks whether this allocation is successful (i.e., is there enough memory or has the program run out of memory). After allocating space, the "read1" module FIG. 15 opens the user-specified file 349 (the "ckopen" module, FIG. 15 at 349, is called to ensure that the query file can be successfully opened 349), determines the query length 343, locates a record with LOCUS in the head-line and extracts the LOCUS name 344 for identification purposes, locates the ORIGIN field in the record and then reads the query sequence from the file 341. Next, the sequence length is determined 345, memory is allocated for the sequence 342, and the sequence is read into the query file 350. If the string has previously been found, processing is returned to 344. If not, then each character in the query file is read into memory 350.
The characters are transformed into digits 346 using the "let -- dig" module, FIG. 11, until a valid digit has been found, and then the hash table containing the query is set up 347 using the module "dig -- let", FIG. 16, which transforms the digits into nucleotides represented by the characters "A" 371, "T" 371, "G" 373, "C" 374, and "X" 375 as a default. If the end of the file has not been reached, processing is returned to 344. If it has, the file is closed 348 and the query is then returned to the "read1" module FIG. 15 at 347.
The "q -- colour" module, FIG. 17 (FIG. 13 at 325), is called by the "assembly" module FIG. 13 after the current sequence has been extracted from the GenBank. The "q -- colour" module FIG. 17 performs the heart of the Mismatch Model process in that it performs the comparison between the query and the database or file sequences. If the module finds that there exists a long (i.e., greater than the min -- hit -- length) extended hit, it returns a "1" to the "assembly" module FIG. 14. Otherwise, the "q -- colour" module, FIG. 17, returns a "0".
In the "q -- colour" module, FIG. 17, all DNA positions are analyzed in the following manner. First, the entire DNA sequence is analyzed 391 to see whether each position is equal to zero 392 (i.e., whether it is empty or the sequence is finished). If it is not equal to zero 393, the "q -- colour" module FIG. 20 calls the "tran" module, FIG. 10 described above, which performs the hashing of k -- tuples. The "tran" module FIG. 10 calls other modules which transform the nucleotides represented by characters into digits for easier processing by the program and then updates the hash with a sliding window. If the position is equal to zero, the current -- hash position is set to new -- has after one shift of old -- hash 390 by calling the "update" module FIG. 12.
If the nucleotide at the current -- hash position is equal to zero, processing is returned to 391. If not, the query position is set equal to (nucleotide at current hash position - 1). Next, the "q -- colour" module FIG. 17 looks for the current -- hash in the hash table 394. If the current k -- tuple does not match the query 395, then the next k -- tuple is considered 395, and processing is returned to 391. If the current k -- tuple does match the query, then the program checks the hit's (i.e., the match's) vicinity 396 by calling the "hit -- ext" module, FIG. 18 to determine if the hit is weak. The inventors have found that if the code for the module "hit -- ext" is included within the module "q -- colour", rather than being a separate module utilizing the parameter transfer machinery, 25% of CPU time can be saved.
The "hit -- ext" module FIG. 18 determines the current query position in the hit's vicinity 421, determines the current DNA position in the hit's vicinity 422, and creates the list of mismatch positions (i.e., the mismatch -- location -- ahead 423, the mismatch -- location -- behind 423 and the kernel match location). If the hit is weak 424, the "hit -- ext" module FIG. 18 returns "0" to the "q -- colour" module FIG. 17. If the hit has a chance to contain 425, the module returns "1" to the "q -- colour" module FIG. 17. A hit has a chance to contain, and is therefore not considered weak, if the mismatch -- location -- ahead the mismatch -- location -- behind is greater than the min -- hit -- length. If not, it is a short hit and is too weak.
If the "hit -- ext" module FIG. 18 tells the "q -- colour" module FIG. 17 that the hit was not a weak one, then the "q -- colour" module determines whether the current hit is long enough 398 by calling the "colour" module FIG. 19. The "colour" module FIG. 19 performs query -- colour modification by the hit data, starting at pos -- query and described by mismatch -- location -- ahead and mismatch -- location -- behind. After the variables to be used in this module are defined, variable isw -- print (which is the switch indicating the hit length) is initialized to zero 430. The cur -- length is then set equal to the length of the extending hit 431 (mismatch -- location -- behind[i]+mismatch -- location -- ahead[j]-1 ). Next, if cur -- length is greater than or equal to the min -- hit -- length 432 (i.e., the minimum considered probe size), the hit is considered long and isw -- print is set equal to two 433. The value of isw -- print is then returned 434 to the "q -- colour" module FIG. 17.
If the length of the extending hit is longer than the min -- hit -- length, the hit is considered long 399. Otherwise, the hit is considered short. If the hit is short, nothing more is done to the current hit and the module begins again. If, on the other hand, the hit is considered long 399, the "q -- colour" module FIG. 17 prints the current extended hit 400. The current extended hit can be printed in ASCII, printed in a binary file, or printed to a memory file. The "q -- colour" module FIG. 17 then repeats until the end of the linked list is reached.
d. Outputs
The output of the k -- diff program in the current implementation of this invention may be either a binary file containing the number of extended hits and the k -- mismatch hit locations (see FIG. 20), or the output may be kept in memory without writing it to a file. See Section l(d)(iv) for more detail.
3. Description of the H-Site Model Program
a. Overview
In this invention, the second hybridization strength model is termed the H-Site Model (see FIG. 2 for user selection of this model). One aspect of the H-Site Model uses a generalization of an experimental formula in general usage. The formula used in the H-Site Model is an expression of the fact that melting temperature Tm is a function of both probe length and percent of GC content. This basic formula has been modified in this invention to account for the presence of mismatches. Each percent of mismatch reduces the melting temperature Tm by an average of 1.25 degrees (2 degrees C. for an AT mismatch, and 4 degrees C. for a GC mismatch).
In addition, this implementation of the invention does some preliminary preprocessing of the GenBank database to sort out and select the cDNA sequences. This is done by locating a keyword (in this case CDS) in each GcnBank record. No other programs currently available allow for this combination of functions as far as the inventors are aware.
There are a number of modules in the present embodiment of the H-Site Model contained in this invention. Each step of the processing involved in the H-Site Model is more fully explained below, and is accompanied by detailed flow charts.
b. Inputs
There are two basic user-selected inputs for the H-Site Model (see FIG. 2C): 1) the melting temperature Tm 22 for which probes are being designed (i.e., the melting temperature that corresponds to a particular experiment or condition the user desires to simulate); and 2) the nucleation threshold 23, which is the number of base pairs constituting a nucleation site. The user is also required to select the 1) target species 11 gene sequence(s) (DNA, mRNA or cDNA) for which probes are being designed; 2) the preparation 12 of all sequences with which hybridizations are to be calculated; and 3) the probe output file 13. The preparation file is the most important, as discussed below.
c. Organization of the H-Site Model Program
The current implementation of the H-Site Model program of this invention is distributed between five files containing numerous modules. The main file is designated by the inventors as "ds.cpp" in its uncompiled version. This file provides overall control to the entire invention. It is divided into six sections. Section 0 defines and manipulates global variables. Section 1 controls general variable definition and initialization (including the arrays and memory blocks). It also reads and writes buffers for user input selections, and constructs multi buffers.
Section 2 sets up and initializes various "snippet" variables (see section below for a complete definition of the term snippet), converts base pair characters to a representation that is 96 base pairs long and to ASCII base pair strings, and performs other sequence file manipulation such as comparing snippets. This section also reads the sequence format file, reads base pairs, checks for and extracts sequence identification information (such as ORIGIN and LOCUS) and filters out sequences beginning with :numbers.
Section 3 involves preparation file manipulation. This section performs the preprocessing on the PRP file discussed above. It also merges and sorts the snippet files, creates a PRP file and sorts it, and outputs the sorted snippets. Next, this section streams through the PRP file.
Section 4 contains the essential code for H-Site Model processing (see FIGS. 21 through 23 for details, discussed below). Streams are set up, and then RIBI comparisons are performed for hybridizations (see file "ribi.cpp" for definitions of RIBI search techniques). Next, probes are generated, binding strength is converted to melting temperature, and hybridizations are calculated and stored (including hybridization strength). Lastly, other H-Site calculations are performed.
Section 5 is concerned with formatting and presenting diagnostic and user file (test.out, testl.out, and test2.out files) output. This section also handles the graphing functions (the MPSD diagram in particular). In addition, this section calculates the hairpin characteristics for the H-Site Model candidate probes.
The second H-Site Model file, designated as "ds.h" defines data variables and structures. Section 1 of this file concerns generic data structures (including memory blocks and arrays, and file inputs and outputs). Section 2 defines the variables and structures used with sequences, probes and hybridizations. Section 3 defines variables and structures concerned with protocols (i.e., function prototypes, graphing, etc.).
The third H-Site Model file, designated as "funcdoc.txt", contains very detailed documentation for this implementation of the H-Site Model program. Numerous variables and structures are also defined. The flow of the program is clearly shown in this file.
The fourth H-Site Model file, designated as "ribi.h" handles the sequence comparisons. The fifth and last H-Site Model file, designated as "ribi.cpp", performs internal B-Tree indexing. Definitions of Red-black Internal Binary Index (RIBI) searching are found in this file. Definitions are also included for the concepts keyed set, index, binary tree, internal binary index, paths, and red-black trees. Implementation notes are also included in this file.
d. Processing
Implementation of the H-Site Model in this invention is done in three stages. First, the invention creates the preparation (PRP) file, which contains all relevant information from the sequence database. This is the preprocessing stage discussed above. Next, the target is prepared by the program. Lastly, the invention calculates the MPSD data using the PRP file and target sequence to find probes.
i. Creation of the Preprocesscd Preparation File
FIG. 21. Step 1: The program first opens the sequence database for reading into memory 461, 462. Step 2: Next, as sequence base pairs are read in 462, "snippets" are saved to disk 463, along with loci information. A snippet is a fixed-length subsequence of a preparation sequence. The purpose of snippets is to allow the user to examine a small portion of a preparation sequence together with its surrounding base pairs. Snippets in the implementation of this invention are 96 base pairs long (except for snippets near the end or beginning of a sequence, which may have fewer base pairs). The "origin " of the snippet is in position 40. For snippets taken :near the beginning of a sequence, some of the initial 40 bases are undefined. For snippets near the end of a sequence, some of the final 55 bases are undefined. Snippets are arranged in the preparation file (PRP) in sorted order (lexicographical order beginning at position 40). In this invention, the term "lexicographical order" means a preselected order, such as alphabetical, numeric or alphanumeric. In order to conserve space, snippets are only taken at every 4th position of the preparation sequence.
Step 3: The snippets are merge sorted 464 to be able to search quickly for sequences which pass the "screen", discussed below. Step 4: The merged file is prepended with identifiers for the sources of the snippets 465. This is done to identify the loci from which hybridizations arise.
ii. Target Preparation
FIG. 22. Step 1: The target sequence file is opened 471 and read into memory 472. For each position in the target mRNA, the probe defined at that starting position is the shortest subsequence starting at that position whose hybridization strength is greater than the user specified melting temperature Tm. Typically, the probes are of length 18 to 50. Step 2: Four lists of "screens" are formed 473, 474, 475, each shifted by one base pair 475 to correspond to the fact that snippets are only taken at every four base pairs. A screen is a subsequence of the target mRNA of length equal to the screening threshold specified by the user. The screens are then indexed 476 and sorted in memory 477.
iii. Calculation of the MPSD Data
FIG. 23. Step 3: This step is the heart of the process. Step 3a: The program streams through the following five items in sync, examining them in sequential order: the snippet file and the four lists of screens 481-484. Step 3b: Each snippet is compared to a screen 485. Step 3c: If the shipper does not match, whichever stream is behind is advanced 486 and Step 3b is repeated. If the snippet does match, Step 4 is performed.
Step 4: If a snippet and a matching screen were found in Step 3b 487, the hybridization strength of the binding between the sequence containing the snippet and all of the probes containing the screen is calculated (see Step 5). Double counting is avoided by doing this only for the first matched screen containing the probe. Each pair of bases is examined and assigned a numerical binding strength. An AT pair would be assigned a lower binding strength than a GC pair because AT pairs have a lower melting temperature Tm. The process is explained more fully below at Step 5b.
Step 5: The hybridization strengths between sequence and all the probes containing it are calculated using a dynamic programming process. The process is as follows: Step 5a: Begin at the position of the first probe containing the given screen but not containing any other screens which start at an earlier position and also match the sequence. This is done to avoid double counting. Two running totals are maintained: a) boundStrength, which represents the hybridization strength contribution which would result if the sequence and probe were to match exactly for all base pairs to the right of the current position, and b) unboundStrength, which represents the strength of the maximally binding region. Step 5b: At each new base pair, the variable bound Strength is incremented by 71 if the sequence and probe match and the matched base pair is GC 489, incremented by 30 if the matched base pair is AT 490 (i.e., this number is about 42.25% of the first number 71), and decremented by 74.5 if there is not a match 488 (i.e., this number is about 5% larger than the first number 71). Step 5c: If the current boundStrength exceeds the current unboundStrength 491 (which was originally initialized to zero), a new binding region has been found, and unboundStrength is set equal to boundStrength 492. Step 5d: If the current boundStrength is negative, boundStrength is reset to zero 493. Step 5e: If the current position is at the end of a probe, the results (the hybridization strengths) are tallied for that probe. Step 5f: If the current position is at the end of the last probe containing the screen, the process stops.
Step 6: A tally is kept of the number and melting temperature of the matches for each candidate probe, and the location of the best 20 candidates, using a priority queue (reverse order by hybridization strength number) 494. Step 7: A numerical "score" is kept for each preparation sequence by tallying the quantity exp (which can be expressed as Εe - ™) for each match 495, where Tm is the melting temperature for the "perfect" match, the probe itself. In other words, the probe hybridizes "perfectly" to its target.
Step 8: Hairpins are calculated by first calculating the complementary probe. In other words, the order of the bases in the candidate probe are reversed (CTATAG to GATATC), and complementary base pairs are substituted (A for T, T for A, G for C, and C for G, changing GATATC to CTATAG in the above example). Next, the variable representing the maximum hairpin length for a candidate probe is initialized to zero, as is the variable representing a hairpin's distance. For each offset, the original candidate probe and the complementary probe just created are then aligned with each other and compared. The longest match is then found. If any two matches have the same length, the one with the longest hairpin distance (i.e., the number of base pairs separating the match) is then saved.
Step 9: The preparation sequences are then sorted 496 and displayed in rank order, from best to worst 497. Step 10: The resulting MPSD, which includes all candidate probes, is then displayed on the screen. Step 11: The best 20 matches are also printed or displayed in rank order, as the user requests 497.
e. Outputs
The outputs of the H-Site Model as currently implemented in this invention are fully described in Section l(d)(iv), above, and illustrated in FIGS. 4 through 6. Samples of the two output files created by the H-Site Model are shown in FIGS. 24A and 24B.
4. Description of the Mitsuhashi Probe Selection Diagram Processing
Once the Mitsuhashi Probe Selection Diagram (MPSD) data has been calculated by the H-Site Model program (see stage three and FIG. 23, discussed above), it is necessary to convert this data to pixel format and plot a graph. An overview of this process is shown in FIG. 25. First, the program calculates the output (x,y) ranges 500. Next, these are converted to a logarithmic scale 501. The values are then interpolated 502, and a bitmap is created 503. Lastly, the bitmap is displayed on the screen 504 in MPSD format (discussed above in section 1(e)(i)). A sample MPSD is shown in FIG. 4.
5. Description of the Matchinfo Window Processing
The ProbeInfo and MatchInfo windows are discussed in great detail in Section 1(e)(ii), and a sample of these windows is shown in FIG. 5. An overview of the processing involved in creating the MatchInfo portion of the window is given in the flow chart in FIG. 26. First, as the user moves the MPSD cursor 520 (seen as a vertical line bisecting the MPSD window), the program updates the position of the candidate probe shown under that cursor position 521. Next, based upon the candidate probe's position, the program updates the sequence 522 and hairpin information 523 for that probe. This updated information is then displayed in an updated match list 524, shown in the MatchInfo window.
The above described embodiments of the present invention are merely descriptive of its principles and are not to be considered limiting. The scope of the present invention instead shall be determined from the scope of the following claims including their equivalents.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 15(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1044 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vii) IMMEDIATE SOURCE:(B) CLONE: HUMBJUNX(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:ATGTGCACTAAAATGGAACAGCCCTTCTACCACGACGACTCATACACAGCTACGGGATAC60GGCCGGGCCCCTGGTGGCCTCTCTCTACACGACTACAAACTCCTGAAACCGAGCCTGGCG120GTCAACCTGGCCGACCCCTACCGGAGTCTCAAAGCGCCTGGGGCTCGCGGACCCGGCCCA180GAGGGCGGCGGTGGCGGCAGCTACTTTTCTGGTCAGGGCTCGGACACCGGCGCGTCTCTC240AAGCTCGCCTCTTCGGAGCTGGAACGCCTGATTGTCCCCAACAGCAACGGCGTGATCACG300ACGACGCCTACACCCCCGGGACAGTACTTTTACCCCCGCGGGGGTGGCAGCGGTGGAGGT360GCAGGGGGCGCAGGGGGCGGCGTCACCGAGGAGCAGGAGGGCTTCGCCGACGGCTTTGTC420AAAGCCCTGGACGATCTGCACAAGATGAACCACGTGACACCCCCCAACGTGTCCCTGGGC480GCTACCGGGGGGCCCCCGGCTGGGCCCGGGGGCGTCTACGCCGGCCCGGAGCCACCTCCC540GTTTACACCAACCTCAGCAGCTACTCCCCAGCCTCTGCGTCCTCGGGAGGCGCCGGGGCT600GCCGTCGGGACCGGGAGCTCGTACCCGACGACCACCATCAGCTACCTCCCACACGCGCCG660CCCTTCGCCGGTGGCCACCCGGCGCAGCTGGGCTTGGGCCGCGGCGCCTCCACCTTCAAG720GAGGAACCGCAGACCGTGCCGGAGGCGCGCAGCCGGGACGCCACGCCGCCGGTGTCCCCC780ATCAACATGGAAGACCAAGAGCGCATCAAAGTGGAGCGCAAGCGGCTGCGGAACCGGCTG840GCGGCCACCAAGTGCCGGAAGCGGAAGCTGGAGCGCATCGCGCGCCTGGAGGACAAGGTG900AAGACGCTCAAGGCCGAGAACGCGGGGCTGTCGAGTACCGCCGGCCTCCTCCGGGAGCAG960GTGGCCCAGCTCAAACAGAAGGTCATGACCCACGTCAGCAACGGCTGTCAGCTGCTGCTT1020GGGGTCAAGGGACACGCCTTCTGA1044(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 996 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vii) IMMEDIATE SOURCE:(B) CLONE: HUMCJUNX(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:ATGACTGCAAAGATGGAAACGACCTTCTATGACGATGCCCTCAACGCCTCGTTCCTCCCG60TCCGAGAGCGGACCTTATGGCTACAGTAACCCCAAGATCCTGAAACAGAGCATGACCCTG120AACCTGGCCGACCCAGTGGGGAGCCTGAAGCCGCACCTCCGCGCCAAGAACTCGGACCTC180CTCACCTCGCCCGACGTGGGGCTGCTCAAGCTGGCGTCGCCCGAGCTGGAGCGCCTGATA240ATCCAGTCCAGCAACGGGCACATCACCACCACGCCGACCCCCACCCAGTTCCTGTGCCCC300AAGAACGTGACAGATGAGCAGGAGGGGTTCGCCGAGGGCTTCGTGCGCGCCCTGGCCGAA360CTGCACAGCCAGAACACGCTGCCCAGCGTCACGTCGGCGGCGCAGCCGGTCAACGGGGCA420GGCATGGTGGCTCCCGCGGTAGCCTCGGTGGCAGGGGGCAGCGGCAGCGGCGGCTTCAGC480GCCAGCCTGCACAGCGAGCCGCCGGTCTACGCAAACCTCAGCAACTTCAACCCAGGCGCG540CTGAGCAGCGGCGGCGGGGCGCCCTCCTACGGCGCGGCCGGCCTGGCCTTTCCCGCGCAA600CCCCAGCAGCAGCAGCAGCCGCCGCACCACCTGCCCCAGCAGATGCCCGTGCAGCACCCG660CGGCTGCAGGCCCTGAAGGAGGAGCCTCAGACAGTGCCCGAGATGCCCGGCGAGACACCG720CCCCTGTCCCCCATCGACATGGAGTCCCAGGAGCGGATCAAGGCGGAGAGGAAGCGCATG780AGGAACCGCATCGCTGCCTCCAAGTGCCGAAAAAGGAAGCTGGAGAGAATCGCCCGGCTG840GAGGAAAAAGTGAAAACCTTGAAAGCTCAGAACTCGGAGCTGGCGTCCACGGCCAACATG900CTCAGGGAACAGGTGGCACAGCTTAAACAGAAAGTCATGAACCACGTTAACAGTGGGTGC960CAACTCATGCTAACGCAGCAGTTGCAAACATTTTGA996(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1044 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vii) IMMEDIATE SOURCE:(B) CLONE: HSJUNDR(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:ATGGAAACACCCTTCTACGGCGATGAGGCGCTGAGCGGCCTGGGCGGCGGCGCCAGTGGC60AGCGGCGGCACGTTCGCGTCCCCGGGCCGCTTGTTCCCCGGGGCGCCCCCGACGGCCGCG120GCCGGCAGCATGATGAAGAAGGACGCGCTGACGCTGAGCCTGAGTGAGCAGGTGGCGGCA180GCGCTCAAGCCTGCGCCCGCGCCCGCCTCCTACCCCCCTGCCGCCGACGGCGCCCCCAGC240GCGGCACCCCCCGACGGCCTGCTCGCCTCTCCCGACCTGGGGCTGCTGAAGCTGGCCTCC300CCCGAGCTCGAGCGCCTCATCATCCAGTCCAACGGGCTGGTCACCACCACGCCGACGAGC360TCACAGTTCCTCTACCCCAAGGTGGCGGCCAGCGAGGAGCAGGAGTTCGCCGAGGGCTTC420GTCAAGGCCCTGGAGGATTTACACAAGCAGAACCAGCTCGGCGCGGGCCGGGCCGCTGCC480GCCGCCGCCGCCGCCGCCGGGGGGCCCTCGGGCACGGCCACGGGCTCCGCGCCCCCCGGC540GAGCTGGCCCCGGCGGCGGCCGCGCCCGAAGCGCCTGTCTACGCGAACCTGAGCAGCTAC600GCGGGCGGCGCCGGGGGCGCGGGGGGCGCCGCGACGGTCGCCTTCGCTGCCGAACCTGTG660CCCTTCCCGCCGCCGCCACCCCCAGGCGCGTTGGGGCCGCCGCGCCTGGCTGCGCTCAAG720GACGAGCCACAGACGGTGCCCGACGTGCCGAGCTTCGGCGAGAGCCCGCCGTTGTCGCCC780ATCGACATGGACACGCAGGAGCGCATCAAGGCGGAGCGCAAGCGGCTGCGCAACCGCATC840GCCGCCTCCAAGTGCCGCAAGCGCAAGCTGGAGCGCATCTCGCGCCTGGAAGAGAAAGTG900AAGACCCTCAAGAGTCAGAACACGGAGCTGGCGTCCACGGCGAGCCTGCTGCGCGAGCAG960GTGGCGCAGCTCAAGCAGAAAGTCCTCAGCCACGTCAACAGCGGCTGCCAGCTGCTGCCC1020CAGCACCAGGTCCCGGCGTACTGA1044(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1035 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vii) IMMEDIATE SOURCE:(A) LIBRARY: MUSBJUNX(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:ATGTGCACGAAAATGGAACAGCCTTTCTATCACGACGACTCTTACGCAGCGGCGGGATAC60GGTCGGAGCCCTGGCAGCCTGTCTCTACACGACTACAAACTCCTGAAACCCACCTTGGCG120CTCAACCTGGCGGATCCCTATCGGGGTCTCAAGGGTCCTGGGGCGCGGGGTCCAGGCCCG180GAGGGCAGTGGGGCAGGCAGCTACTTTTCGGGTCAGGGATCAGACACAGGCGCATCTCTG240AAGCTAGCCTCCACGGAACTGGAGCGCTTGATCGTCCCCAACAGCAACGGCGTGATCACG300ACGACGCCCACGCCTCCGGGACAGTACTTTTACCCCCGTGGGGGTGGCAGCGGTGGAGGT360ACAGGGGGCGGCGTCACCGAGGAGCAGGAGGGCTTTGCGGACGGTTTTGTCAAAGCCCTG420GACGACCTGCACAAGATGAACCACGTGACGCCCCCCAACGTGTCCCTGGGCGCCAGCGGG480GGTCCCCAGGCCGGCCCAGGGGGCGTCTATGCTGGTCCGGAGCCGCCTCCCGTCTACACC540AACCTCAGCAGTTACTCTCCAGCCTCTGCACCCTCTGGAGGCTCCGGGACCGCCGTCGGG600ACTGGGAGCTCATACCCGACGGCCACCATCAGCTACCTCCCACATGCACCACCCTTTGCG660GGCGGCCACCCGGCACAGCTGGGTTTGAGTCGTGGCGCTTCCGCCTTTAAAGAGGAACCG720CAGACCGTACCGGAGGCACGCAGCCGCGACGCCACGCCGCCTGTGTCCCCCATCAACATG780GAAGACCAGGAGCGCATCAAAGTGGAGCGAAAGCGGCTGCGGAACAGGCTGGCGGCCACC840AAGTGCCGGAAGCGGAAGCTGGAGCGCATCGCGCGCCTGGAGGACAAGGTGAAGACACTC900AAGGCTGAGAACGCGGGGCTGTCGAGTGCTGCCGGTCTCCTAAGGGAGCAAGTGGCGCAG960CTCAAGCAGAAGGTCATGACCCATGTCAGCAACGGCTGCCAGTTGCTGCTAGGGGTCAAG1020GGACACGCCTTCTGA1035(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1005 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vii) IMMEDIATE SOURCE:(B) CLONE: MUSCJUNX(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:ATGACTGCAAAGATGGAAACGACCTTCTACGACGATGCCCTCAACGCCTCGTTCCTCCAG60TCCGAGAGCGGTGCCTACGGCTACAGTAACCCTAAGATCCTAAAACAGAGCATGACCTTG120AACCTGGCCGACCCGGTGGGCAGTCTGAAGCCGCACCTCCGCGCCAAGAACTCGGACCTT180CTCACGTCGCCCGACGTCGGGCTGCTCAAGCTGGCGTCGCCGGAGCTGGAGCGCCTGATC240ATCCAGTCCAGCAATGGGCACATCACCACTACACCGACCCCCACCCAGTTCTTGTGCCCC300AAGAACGTGACCGACGAGCAGGAGGGCTTCGCCGAGGGCTTCGTGCGCGCCCTGGCTGAA360CTGCATAGCCAGAACACGCTTCCCAGTGTCACCTCCGCGGCACAGCCGGTCAGCGGGGCG420GGCATGGTGGCTCCCGCGGTGGCCTCAGTAGCAGGCGCTGGCGGCGGTGGTGGCTACAGC480GCCAGCCTGCACAGTGAGCCTCCGGTCTACGCCAACCTCAGCAACTTCAACCCGGGTGCG540CTGAGCAGCGGCGGTGGGGCGCCCTCCTATGGCGCGGCCGGGCTGGCCTTTCCCTCGCAG600CCGCAGCAGCAGCAGCAGCCGCCTCAGCCGCCGCACCACTTGCCCCAACAGATCCCGGTG660CAGCACCCGCGGCTGCAAGCCCTGAAGGAAGAGCCGCAGACCGTGCCGGAGATGCCGGGA720GAGACGCCGCCCCTGTCCCCTATCGACATGGAGTCTCAGGAGCGGATCAAGGCAGAGAGG780AAGCGCATGAGGAACCGCATTGCCGCCTCCAAGTGCCGGAAAAGGAAGCTGGAGCGGATC840GCTCGGCTAGAGGAAAAAGTGAAAACCTTGAAAGCGCAAAACTCCGAGCTGGCATCCACG900GCCAACATGCTCAGGGAACAGGTGGCACAGCTTAAGCAGAAAGTCATGAACCACGTTAAC960AGTGGGTGCCAACTCATGCTAACGCAGCAGTTGCAAACGTTTTGA1005(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1026 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to mRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vii) IMMEDIATE SOURCE:(B) CLONE: MUSDJUNX(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:ATGGAAACGCCCTTCTATGGCGAGGAGGCGCTGAGCGGCCTGGCTGCGGGTGCGTCGAGC60GTCGCTGGTGCTACTGGGGCCCCCGGCGGTGGTGGCTTCGCGCCCCCGGGCCGCGCTTTC120CCCGGGGCGCCCCCGACGAGCAGCATGCTGAAGAAAGACGCGCTGACGCTCAGCCTGGCG180GAGCAGGGAGCGGCGGGATTGAAACCAGGGTCGGCCACTGCACCTTCTGCGCTGCGCCCC240GACGGCGCCCCCGACGGGCTGCTGGCTTCGCCGGATCTTGGGCTGCTCAAACTCGCGTCG300CCGGAGCTGGAGAGGCTGATCATCCAGTCCAACGGGCTGGTGACCACTACCCCGACCAGT360ACGCAGTTCCTCTACCCGAAGGTGGCAGCCAGCGAGGAGCAGGAGTTCGCCGAAGGCTTC420GTCAAGGCGCTGGAGGACCTGCACAAGCAAAGCCAGCTGGGTGCGGCCACCGCGGCCACC480TCAGGGGCTCCCGCGCCTCCCGCGCCCGCCGACCTGGCCGCCACCCCCGGGGCCACGGAG540ACCCCGGTCTACGCCAACCTGAGCAGTTTCGCGGGTGGCGCCGGGCCCCCTGGGGGCGCG600GCCACCGTGGCTTTCGCCGCGGAGCCAGTGCCCTTCCCGCCGCCCCCGGGCGCGCTGGGG660CCGCCGCCACCTCCGCATCCACCGCGCCTGGCCGCGCTCAAGGACGAGCCGCAGACCGTG720CCGGACGTGCCGAGCTTCGGCGACAGCCCTCCGCTGTCGCCCATCGACATGGACACGCAA780GAACGCATCAAGGCGGAGCGCAAGAGGCTGCGCAACCGCATCGCCGCCTCCAAATGCCGC840AAGCGCAAGCTGGAGCGTATCTCGCGCCTGGAGGAGAAAGTCAAGACCCTCAAAAGCCAG900AACACCGAGCTGGCGTCCACCGCCAGCCTGCTGCGCGAGCAGGTGGCGCAGCTCAAACAG960AAAGTCCTCAGCCACGTCAACAGCGGCTGCCAGCTGCTGCCCCAGCACCAGGTCCCGGCG1020TACTGA1026(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:AGGCCTCGGTTAGTTGGCCGTTGCCGAAAAA31(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:AGGCGTCGGTTATTTGGGCCTTCCCAATGTG31(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:AGGCGTCGGTTCTGTGGAACTTCCCGAGGAA31(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:AGGCCTCGGTTAGTTGGCCGTTGCCGAAAAA31(2) INFORMATION FOR SEQ ID NO:11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:AGGCGTCGGTTATTTGGGCCTTCCCAATGTG31(2) INFORMATION FOR SEQ ID NO:12:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:AGGCGTCGGTTATTTGGGCCTTCCCAATGTG31(2) INFORMATION FOR SEQ ID NO:13:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:AGGCGTCGGTTCTGTGGAACTTCCCGAGGAA31(2) INFORMATION FOR SEQ ID NO:14:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:AGGCCTCGGTTAGTTGGCCGTTGCCGAAAAA31(2) INFORMATION FOR SEQ ID NO:15:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 31 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:AGGCGTCGGTTATTGTGGTCTCCCCAATGTG31__________________________________________________________________________
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There is disclosed herein an invention which relates to the fields of genetic engineering, microbiology, and computer science, that allows a user, whether they be a molecular biologist or a clinical diagnostician, to calculate and design extremely specific oligonucleotide probes for DNA and mRNA hybridization procedures. The probes designed with this invention may be used for medical diagnostic kits, DNA identification, and potentially continuous monitoring of metabolic processes in human beings. The key features design oligonucleotide probes based on the GenBank database of DNA and mRNA sequences and examine candidate probes for specificity or commonality with respect to a user-selected experimental preparation. Two models are available: a Mismatch Model, that employs hashing and continuous seed filtration, and an H-Site Model, that analyzes candidate probes for their binding specificity relative to some known set of mRNA or DNA sequences. The preferred embodiment of this computerized design tool is written in the Borland® C++ language and runs under Microsoft® Windows™ on IBM® compatible personal computers.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a wet flue gas desulfurization process. More particularly, this invention relates to reducing the amount of purge liquid discharged to a wastewater treatment system from a wet flue gas desulfurization system.
2. Description of the Related Art
Federal, state and even some local governments have laws regulating the emission of particulates, gases and other contaminants present in gas produced in coal combustion. To comply with these laws, industries must implement systems that reduce or eliminate emissions of particulates and/or gases that have been deemed harmful to the environment.
Several technologies and processes have been developed to reduce emissions of such elements. These technologies include desulfurization systems that employ fabric filters, electrostatic precipitators, and wet scrubbers. Desulfurization systems have shown sufficient efficiency in the removal of particulate and gases.
A particularly useful desulfurization system is the wet flue gas desulfurization system. Wet flue gas desulfurization systems (WFGD) purify flue gas which is produced by coal combustion. There are several known designs for WFGD systems. One example of a WFGD system uses small droplets of slurry that contain water and alkaline material, such as lime or limestone, which is sprayed into the flue gas. Another example of a WFGD system bubbles the flue gas through a bed of slurry to remove pollutants. Regardless of the design of the WFGD system, the slurry reacts with sulfur oxides (SO x ) present in the flue gas and removes them from the flue gas stream as precipitated compounds.
Besides the removal of SO x from the flue gas stream, the WFGD system also captures HCl and HF gases, which are removed from the flue gas stream and become water soluble salts: CaCl 2 and CaF 2 , respectively. These salts dissociate and yield free Cl − and F − ions which build up in the WFGD system. This buildup can cause corrosion and other damage in the WFGD system, and can negatively affect SO x removal.
Typically, a stream of water or other liquid, or a slurry containing liquid and particles, referred to as a purge liquid, is used to purge chlorides and other unwanted compounds from the WFGD system. The purge liquid helps maintain a desired chloride concentration, which in turn, helps to protect the equipment of the WFGD system from corrosion. The purge liquid is typically diverted to a wastewater treatment facility.
Typically, wastewater treatment facilities used in conjunction with WFGD systems are expensive. The design and supply cost of such a facility can exceed the cost of other systems used in connection with the WFGD plant. The cost of the wastewater treatment facility is even more pronounced when organic acids are used in the WFGD system.
In addition to operating expense, the wastewater treatment facilities require large portions of land, additional equipment, and several buildings. The capital and operating costs of a wastewater facility are dramatically increased when a biological reactor is required to remove organic acids or other constituents that may be used in or captured by the WFGD system.
BRIEF SUMMARY OF THE INVENTION
One aspect of the invention relates to a method for removing contaminants from a flue gas stream. The method includes: removing fly ash from a flue gas stream utilizing a particle collector; contacting the flue gas stream with an alkaline reagent in a wet scrubber; discharging a purge liquid from the wet scrubber; combining at least a portion of the purge liquid with at least a portion of the fly ash to form moistened fly ash; and injecting at least a portion of the moistened fly ash into the flue gas stream upstream of the particle collector, whereby the moistened fly ash removes at least a portion of contaminants present in the flue gas stream.
Another aspect of the present invention relates to a method of reusing an amount of purge liquid in a flue gas stream treatment system. The method includes the steps of: removing fly ash from a flue gas stream and transporting the fly ash to a solids mixer; combining the fly ash with a purge liquid which has been directed from a wet scrubber to the solids mixer; forming a moistened fly ash from the fly ash and purge liquid; and injecting the moistened fly ash mixture into the flue gas stream, thereby reducing the amount of purge liquid sent to a wastewater treatment plant.
Another aspect of the invention relates to a system for reducing or eliminating an amount of purge liquid sent to a wastewater treatment plant in a flue gas treatment system. The system includes: means for removing fly ash from a flue gas stream and diverting the fly ash to a solids mixer; means for discharging a purge liquid from a wet scrubber and diverting the purge liquid to the solids mixer; means for combining the removed fly ash with at least a portion of the purge liquid to form a moistened fly ash; and means for injecting the moistened fly ash into the flue gas stream.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, the drawings show a form of the invention that is presently preferred. However it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:
FIG. 1 : shows one embodiment of a WFGD system of the present invention;
FIG. 2 : shows one embodiment of a WFGD system of the present invention;
FIG. 3 : shows the injection of moistened fly ash into flue gas produced by a boiler;
FIG. 3A : shows a portion of FIG. 3 in more detail; and
FIG. 4 : shows a flowchart of one embodiment of the present invention.
Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
The processes and systems described herein are typically used in coal-combustion systems; however it is foreseeable to use such processes and systems in waste-to-energy plants, and other facilities that produce a flue gas stream.
Flue gas streams contain, among other things: ash particles, noxious substances and other impurities that are considered to be environmental contaminants. Prior to being emitted into the atmosphere via a smoke stack (“stack”), the flue gas stream undergoes a cleansing or purification process. In coal combustion, this purification process is normally a desulfurization system.
Now referring to FIGS. 1-3 , in which like numerals correspond to like parts, in the WFGD system 20 , a flue gas stream 22 leaves a boiler and travels to a particle collector 24 . Particle collector 24 may be a baghouse, an electrostatic precipitator, a venturi-type scrubber or any similar apparatus that can facilitate the removal of particles from flue gas stream 22 .
Ash and other particulate contaminants (collectively referred to hereinafter as “fly ash”) present in flue gas stream 22 are collected in particle collector 24 . The collected particulate contaminants may be disposed of or may be recycled within WFGD system 20 .
After passing through particle collector 24 , flue gas stream 22 travels to a wet scrubber 26 . Wet scrubber 26 removes acidic gases such as SO 2 from the flue gas by exposing the flue gas to an alkaline reagent. The alkaline reagent can be limestone, lime, or any other alkaline compound, in a slurry, which is sprayed into flue gas stream 22 as droplets. The unreacted alkaline reagent can be recirculated within wet scrubber 26 by utilizing a slurry recirculating line 27 to introduce the alkaline reagent to wet scrubber 26 . The reacted alkaline reagent is fully oxidized to form gypsum by exposing it to air from oxidation air supply line 23 .
After contacting the flue gas stream 22 with the alkaline reagent, the flue gas stream is transported to a stack 28 for release into the atmosphere. Flue gas stream 22 may be subjected to other reagents, or one or more devices, that facilitate the removal of contaminants prior to being released into the atmosphere via stack 28 . Other treatments include, but are not limited to, mercury removal via contact with a reagent such as activated carbon, additional particulate collection, and the like.
The reaction of the alkaline reagent with the acidic components of flue gas stream 22 in wet scrubber 26 produces salt and water. In addition, HCl and HF gases react to form water soluble salts that dissociate to form free Cl − and F − ions in the alkaline reagent. As discussed above, the increase of chloride ions tends to corrode the system and results in a chloride concentration in the alkaline reagent, which hinders the removal of acidic components from flue gas stream 22 .
To prevent an unacceptable chlorine ion (Cl − ) concentration, and to alleviate the corrosive tendencies of Cl − and the negative effect Cl − has on SO x removal within wet scrubber 26 , most WFGD systems use a purge liquid 30 to control the chloride level within the system. Purge liquid 30 typically also removes fine particulate material that is present in wet scrubber 26 . Purge liquid 30 is typically sent to a wastewater treatment system or plant before it is discharged into the environment.
Purge liquid 30 is discharged from wet scrubber 26 at point 32 . After it is discharged from wet scrubber 26 , purge liquid 30 is then sent to a holding tank or other system component that diverts the purge liquid to be transported to a wastewater treatment plant. Purge liquid 30 is mainly water, reacted and unreacted alkaline reagent and contains water soluble ions such as Cl − , however some particulates, known as “fines” may be in the purge liquid as well.
In one embodiment of the present invention, purge liquid 30 is transported from wet scrubber 26 to hydrocyclone 34 . Hydrocyclone 34 utilizes centrifugal force to separate particulate matter from the purge liquid. The particulate matter, together with a small amount of purge liquid 30 , referred together as underflow liquid, drops down into a tank, a reservoir, or a vacuum filter 36 and can then be transported through process stream 38 to a separate system or apparatus used to collect gypsum.
Purge liquid 30 purified by hydrocyclone 34 , and not containing particulate matter or containing a small fraction of particulate matter, and referred to as overflow, travels by gravity through pipework to a storage tank 40 . Substantially all of purge liquid 30 from hydrocyclone 34 is transported to storage tank 40 . Any purge liquid 30 not diverted to storage tank 40 is typically sent to vacuum filter 36 along with any particulate matter. However, in one embodiment, a portion of purge liquid 30 that has been purified by hydrocyclone 34 can be recycled to wet scrubber 26 . Purge liquid 30 is not sent to a wastewater treatment plant.
After purge liquid 30 reaches storage tank 40 , the purge liquid travels via a pump 42 to a solids mixer 44 . Optionally, a process heater 46 may be installed to be in contact with purge liquid 30 as it is transported by pump 42 to solids mixer 44 . Process heater 46 , which can be electric or steam driven, is used to heat the purge liquid prior to delivering it to solids mixer 44 .
A portion of collected fly ash 48 from particle collector 24 is transported to the solids mixer 44 as well. Fly ash 48 may be directed to solids mixer 44 from particle collector 24 by fluidized troughs, pneumatic transfer, or by any other means for transporting dry ash known by those skilled in the art.
As shown particularly in FIG. 2 , the amount of purge liquid 30 entering solids mixer 44 may be regulated by a control valve 50 . Control valve 50 is optionally connected to a user interface 52 , which may be, for example, a keyboard, a monitor or a computer, or other device that allows a user to increase, decrease or stop the transportation of purge liquid 30 into solids mixer 44 . Additionally, as shown in FIG. 3 , control valve 50 may optionally be connected to a device 51 , which measures the temperature at a point 53 located behind particle collector 24 .
Also as shown in FIG. 2 , a sliding gate, rotary valve or other control mechanism 54 , may be used to regulate the amount of fly ash 48 that enters solids mixer 44 . Likewise, control mechanism 54 may be connected to a user interface 56 that allows a user to increase, decrease or stop the transportation of fly ash 48 to solids mixer 44 . Excess fly ash 48 not directed to solids mixer 44 may be brought to an ash storage facility or an ash disposal system by process stream 58 .
Within solids mixer 44 , purge liquid 30 moistens fly ash 48 to form a moistened fly ash 60 . Moistened fly ash 60 can be in a dry free flowing form or can be in a slurry form.
When fly ash 48 is moistened, any unreacted alkaline particles (i.e. calcium and/or magnesium) present in the fly ash will become activated. The activated alkaline particles in moistened fly ash 60 are utilized to remove contaminants from flue gas stream 22 .
In one embodiment, the proportions of fly ash 48 and purge liquid 30 are controlled to ensure that moistened fly ash 60 remains dry, fluffy and free flowing. The ratio of fly ash 48 to purge liquid 30 is maintained sufficiently high to keep moistened fly ash 60 free flowing. In this embodiment the moistened fly ash contains between about 94% to about 98% by weight of fly ash based on the total weight of moistened fly ash 60 . However, the amount of fly ash in moistened fly ash 60 is typically between about 94% and about 95% by weight of the total weight of the moistened fly ash. To ensure the correct ratio, the moisture of the moistened fly ash 60 in solids mixer 44 is monitored by a humidistat 62 which is operatively connected to solids mixer 44 .
Alternatively, in another embodiment, the moistened fly ash 60 contains more purge liquid 30 making the moistened fly ash more slurry-like. Moistened fly ash 60 of this embodiment is formed by mixing purge liquid 30 with fly ash 48 in solids mixer 44 . To form the slurry-like moistened fly ash 60 , the moistened fly ash contains about 30% to about 50% by weight of fly ash based on the total weight of the moistened fly ash.
Utilizing moistened fly ash 60 in a dry free-flowing form is advantageous in systems that have limited space or have limited access to water sources. Utilizing moistened fly ash 60 in a slurry-like form is advantageous in systems that have flue gas streams with very high temperatures or contain a high amount of sulfur therein.
Once moistened fly ash 60 is formed, either in its substantially free flowing or slurry form, it is then introduced to newly produced flue gas 22 . Moistened fly ash 60 is typically injected into flue gas stream 22 at a position 64 upstream of particle collector 24 . However, moistened fly ash 60 can be injected into flue gas stream 22 at any position that allows the moistened fly ash to contact and remove contaminants from the flue gas stream.
Moistened fly ash 60 may be transported from solids mixer 44 to position 64 by a pump 61 . Optionally, air from pump 65 may be introduced to moistened fly ash 60 before it is introduced to flue gas stream 22 .
As shown particularly in FIGS. 3 and 3A , moistened ash 60 flows out of solids mixer 44 through mixer outlets 66 and down an ash injection chute 68 . Ash injection chute 68 can be a simple flat plate or it may have a perforated or sawtooth design. Ash injection chute 68 promotes even distribution of the moistened fly ash across the width of the duct flue gas stream 22 travels in.
Below ash injection chute 68 may be a false wall 70 , which accelerates the speed of flue gas stream 22 to the proper velocity at which moistened fly ash 60 can be entrained into the flue gas stream.
Once moistened fly ash 60 is introduced to flue gas stream 22 , the moisture is evaporated therefrom and humidifies the flue gas stream. During the evaporation, moistened fly ash 60 acts as a reagent to remove SO 2 , HCl and other acidic components in flue gas stream 22 . After moistened fly ash 60 is dehumidified, it is brought back to particulate collector 24 where it is collected or removed as discussed in more detail above. If organic acids such as dibasic acid (DBA) or adipic acid are used in system 20 , they are evaporated and captured in particle collector 24 . If a fabric filter is used in the system, even greater SO 2 and HCl removal is achieved.
The embodiments described herein decrease the amount of fresh alkaline reagent needed by the system overall. Further, the embodiments described herein reduce or eliminate transporting used purge liquid 30 to a wastewater treatment plant.
As illustrated in the process sequence of FIG. 4 , in step 72 , at least a portion of the fly ash present in flue gas stream 22 is removed from the flue gas stream. The fly ash is removed by introducing flue gas stream 22 into a particle collector 24 .
In step 74 , flue gas stream 22 is then introduced to a wet scrubber 26 , where in step 76 it is contacted with an alkaline reagent. As described in more detail above, the alkaline reagent is typically an alkaline compound that reacts with any acidic components present in flue gas stream 22 . The reaction of the alkaline reagent with the acidic components results in the production of corrosive chloride ions.
To remove the corrosive chloride ions, in step 78 , a purge liquid 30 removes corrosive chloride ions from wet scrubber 26 . After collecting at least a portion of the chloride ions from wet scrubber 26 , purge liquid 30 is discharged from the wet scrubber and sent to hydrocyclone 34 .
After the particulate material is removed or reduced from purge liquid 30 , in step 80 the purge liquid is combined with at least a portion of fly ash 48 collected from particle collector 24 . The combination of purge liquid 30 and fly ash 48 form a moistened fly ash 60 .
As shown in step 82 , moistened fly ash 60 is then injected into flue gas stream 22 at a point 64 upstream of particle collector 24 . The moisture from moistened fly ash 60 is evaporated therefrom, thereby humidifying flue gas stream 22 and dehumidifying the fly ash. During evaporation moistened fly ash 60 serves as a reactant to collect and remove contaminants from the flue gas stream.
One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
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One aspect of the invention relates to a method for removing contaminants from a flue gas stream ( 22 ). The method includes: removing fly ash from a flue gas stream ( 22 ) utilizing a particle collector ( 24 ); contacting the flue gas stream with an alkaline reagent in a wet scrubber ( 26 ); discharging a purge liquid ( 30 ) from the wet scrubber ( 26 ); combining at least a portion of the purge liquid ( 30 ) with at least a portion of the fly ash ( 48 ) to form moistened fly ash ( 60 ); and injecting at least a portion of the moistened fly ash ( 60 ) into the flue gas stream ( 22 ) upstream of the particle collector ( 24 ), whereby the moistened fly ash ( 60 ) removes at least a portion of contaminants present in the flue gas stream ( 22 ).
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CROSS-REFERENCES TO RELATED APPLICATIONS
The present application claims priority to European Patent Application No. EP 10 004 141.7, filed Apr. 19, 2010. The disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
The invention relates to methods of inspecting semiconductor substrates and to methods of processing semiconductor substrates. The invention also relates to methods of manufacturing semiconductor devices and to devices manufactured using such methods.
BACKGROUND OF THE INVENTION
A semiconductor wafer substrate generally includes a front side having integrated circuits formed thereon, and a bulk of semiconductor material providing the back side of substrate. Prior to bonding and packaging of individual integrated circuit chips or bonding to other semiconductor substrates, the wafer substrate is typically thinned to remove unwanted semiconductor material or to expose through wafer vias embedded in the substrate to provide electrical contact from the back side to the integrated circuits formed on the front side.
It is desirable to perform the thinning of the wafer with a high accuracy which is uniform across the wafer such that a remaining thickness of the wafer has a desired value or such that a residual thickness measured between tip ends of the through wafer vias embedded in the substrate and the back surface of the wafer has a desired value.
BRIEF SUMMARY OF THE INVENTION
The present invention has been accomplished taking the above problems into consideration.
According to embodiments of the present invention, the processing of semiconductor substrates includes optical methods to determine a distance between a piece of metal embedded in a semiconductor substrate and a back surface of the substrate.
According to other embodiments, optical methods are used to detect pieces of metal embedded in the substrate and not exposed at the back surface of the substrate and to control a wafer thinning process based on such detection.
According to particular embodiments herein, information gained by the optical methods from one wafer can be used to control a subsequent thinning process applied to the same wafer or to control a thinning process applied to a next wafer.
According to other particular embodiments herein, other information, such as information relating to grinding marks detected on the back surface, can be used to control a subsequent grinding process applied to a next wafer.
According to exemplary embodiments, the optical methods include directing measuring light towards the back surface of the substrate and detecting a portion of the measuring light received back from the substrate. According to exemplary embodiments herein, the direction of measuring light towards the back surface and the detection of the portion of measuring light received back from the substrate uses a dark field configuration. A minimum angle between a direction of a portion of the measuring light reflected off the back surface and a direction of the portion of the measuring light received back from the substrate is greater than 10°, greater than 20° or greater than 30°. The inventors have found that a dark field configuration which is conventionally used to detect defects, such as particles or scratches, on a substrate surface can be successfully applied to detect features embedded in the bulk of the substrate. Such features may comprise pieces of metal embedded in a substrate made of semiconductor material.
According to embodiments, the optical methods comprise imaging of a portion of the substrate onto a position sensitive detector. According to exemplary embodiments herein, a lateral extension of the feature embedded in the bulk of the substrate is at least 2 times smaller or at least 5 times smaller than a lateral resolution of the imaging of the portion of the substrate onto the position sensitive detector. According to other exemplary embodiments herein, a lateral extension of a region of a substrate imaged onto one single pixel of a position sensitive detector is at least ten times greater or at least 20 times greater than a lateral extension of the features embedded in the substrate.
According to other embodiments, the optical methods include directing of a measuring light beam onto the substrate such that a lateral extension of the beam of measuring light on the back surface is at least 2 times greater, at least 5 times, at least 10 times, or at least 100 times greater than a lateral extension of the feature embedded in the substrate. Herein, the beam of measuring light can be scanned across the substrate to generate an image of the substrate and to perform the optical methods at plural locations of the substrate.
According to embodiments, measuring light used in the optical methods has wavelengths selected such that a penetration depth of the measuring light into the substrate material is greater than 0.2 times, 0.5 times or 1.5 times a distance between features embedded in the substrate and the back surface of the substrate. According to exemplary embodiments herein, the substrate material is silicon, and the wavelengths of the measuring light are greater than 500 nm, 550 nm, 600 nm or 650 nm.
According to exemplary embodiments, wavelengths of measuring light used in the optical methods are selected such that a penetration depth of the measuring light into the substrate is less than 2.0 times, 1.0 times or 0.5 times a distance between the back surface of the substrate and a front surface of the substrate opposite to the back surface. According to exemplary embodiments herein, the substrate material is silicon, and the wavelengths of the measuring light are smaller than 900 nm, 850 nm, 800 nm or 750 nm.
According to exemplary embodiments, the pieces of metal embedded in the substrate material are through wafer vias, i.e. conductive connectors extending from a front side of the substrate into the substrate.
According to embodiments, a thinning process is applied to a back side of the substrate to remove substrate material. According to exemplary embodiments herein, the thinning process comprises grinding and/or etching. The thinning process may be controlled based on information gained in one of the optical methods disclosed in this application.
According to embodiments, a method of manufacturing a semiconductor device is provided, wherein the method comprises forming semiconductor structures and through wafer vias on a front side of a first semiconductor substrate, bonding the first substrate with its front side to a carrier, applying at least one thinning process to the first substrate by removing substrate material at a back side of the substrate such that the through wafer vias are exposed at the back side, and bonding at least one second substrate to the first substrate, wherein the at least one thinning process is controlled based on information gained from one of the optical methods illustrated above.
BRIEF DESCRIPTION OF THE DRAWINGS
The forgoing as well as other advantageous features of the invention will be more apparent from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. It is noted that not all possible embodiments of the present invention necessarily exhibit each and every, or any, of the advantages identified herein.
FIG. 1 is a schematic illustration of a cross section of a wafer substrate having through wafer vias embedded therein;
FIG. 2 is a schematic illustration of an optical method;
FIG. 3 is a schematic illustration of another optical method;
FIGS. 4 a , 4 b and 4 c are images obtained by the optical method illustrated in FIG. 2 at different residual depths of a substrate;
FIG. 5 is a graph illustrating a dependency of a residual depth and image intensity;
FIG. 6 is a graph showing a dependency of a penetration depth of measuring light in a substrate depending on wavelengths;
FIG. 7 is a flowchart illustrating a method of manufacturing of a semiconductor device.
DETAILED DESCRIPTION OF THE INVENTION
In the exemplary embodiments described below, components that are alike in function and structure are designated as far as possible by alike reference numerals. Therefore, to understand the features of the individual components of a specific embodiment, the descriptions of other embodiments and of the summary of the invention should be referred to.
The embodiments illustrated below generally relate to manufacture of semiconductor devices and to thinning of wafers and in particular to thinning of such wafers including through wafer vias which are to be exposed at a back side of the wafer by applying a thinning process to the back side of the wafer. Background information relating to thinning of wafers and to wafers including through wafer vias can be obtained from U.S. Pat. No. 7,214,615 B2, U.S. Pat. No. 6,916,725 B2,US 2010/0038800 A1, US 2010/0032764 A1, US 2005/0158889 A1 and US 2010/0041226 A1, wherein the full disclosure of these documents is incorporated herein by reference.
Further information to manufacture of semiconductor devices involving thinning of a wafer can be obtained from the article “Stress Analysis on Ultra Thin Ground Wafers” by Ricardo C. Teixeira et al., Journal Integrated Circuits and Systems 2008, v.3/n.2:81-87 and from the article “New Hybrid Bonding Approach for 3D Stacking of ICs” by Anne Jourdain et al., Chip Scale Review, August/September 2009, pages 24 to 28.
The illustrated embodiments relate to thinning of wafers and involve optical methods used for determining a residual thickness between tip ends of through wafer vias and a back surface of a wafer and for obtaining information which can be used for controlling a thinning process. These optical methods are, however, not limited to those applications. The optical methods can be also applied to other substrates in which features are embedded in the substrate such that they are located below a surface of the substrate.
FIG. 1 is a schematic illustration of a cross section of a semiconductor wafer in a manufacturing process for semiconductor devices. The wafer 1 has a front surface 6 at a front side 3 and a back surface 5 at a back side 4 . A plurality of semiconductor devices 7 , such as field effect transistors, are formed at the front side 3 of the wafer 1 by applying a plurality of lithographic steps and other manufacturing steps to the front side 3 of the wafer 1 . Through wafer vias 9 extend from the front side 3 into the substrate material of the wafer 1 . The through wafer vias 9 can be formed by conventional methods, such as etching trenches into the substrate, depositing insulating material on trench walls and filling the trenches with a conductive material, such as copper. The through wafer vias have a high aspect ratio and extend into the substrate of the wafer such that tip ends 11 of the through wafer vias 9 are located at a residual distance d 1 from back surface 5 of the wafer 1 . Exemplary values of the residual distance d 1 after manufacture of the through wafer vias 9 include 630 μm and 730 μm, depending on a thickness of the wafer 1 .
One or more wafer thinning processes will be applied to the wafer 1 schematically illustrated in FIG. 1 to expose the vias 9 at the back surface of the wafer. The thinning process includes removal of substrate material from the back surface 5 of the wafer 1 .
A broken line 5 ′ in FIG. 1 illustrates a position of the back surface of the wafer after thinning such that the vias 9 are exposed and project a distance d 2 from the surface. Exemplary values of the distance d 2 are 1 μm and 2 μm, for example. It is apparent that the thinning process has to be performed with a high accuracy to maintain the achieved distances d 2 within an acceptable range for all the vias 9 distributed across the substrate 1 . Therefore, it is desirable to control the one or more thinning processes based on measurements. A conventional optical measurement to control wafer thinning is known from US 2005/0158889 A1 and measures a distance between the back surface 5 and the front surface 4 of the wafer. This conventional optical measurement method uses infrared light having a penetration depth in the wafer material which is greater than the distance between the front and back surfaces. Problems in the conventional method may occur if it is not possible to precisely detect the front surface of the wafer due to a presence of a carrier substrate onto which the wafer is attached with its front side 3 , and if a depth by which the vias extend into the substrate is not exactly known or not uniform across the wafer.
Therefore, it is desirable to determine the residual distance d 1 between tip ends 11 and the back surface 6 of the wafer 1 directly, or to at least determine reliable information indicative of the residual distance d 1 . For example, if a predefined threshold residual distance of, for example, 5 μm or 10 μm is reached by applying a grinding method, the thinning process can be continued by applying etching until the tip ends are fully exposed.
FIG. 2 is a schematic illustration of an optical configuration which can be used to perform an optical method for determining the residual thickness d 1 of the wafer 1 schematically illustrated in FIG. 1 . The optical configuration includes a light source 21 to generate measuring light 23 from which a beam 25 of measuring light is shaped by optics 27 . The optics 27 may include one or more lenses and one or more mirrors. The beam 25 is directed onto a portion 29 of the back surface 5 of the wafer 1 under an angle α relative to a surface normal which is greater than, for example, 10°, 20° or 30°.
The portion 29 of the back surface 5 of the wafer is imaged onto a position sensitive detector 31 using imaging optics 33 . The imaging optics 33 may include one or more lenses and one or more mirrors. The position sensitive detector 31 comprises an array of pixels 35 . The position sensitive detector 31 may have a high number of pixels, such as 10,000 or more pixels, wherein a number of only six pixels 35 is shown in FIG. 5 for illustrative purposes. Due to the imaging with imaging optics 33 , there is a one-to-one correspondence between regions on the wafer 1 and individual pixels onto which each region is imaged. Reference numeral 37 indicates an exemplary region on the substrate 1 which is imaged onto the left pixel 35 of detector 31 shown in FIG. 2 . A lateral extension d 3 of the region 37 imaged onto the one pixel 35 is, for example, 100 μm. This lateral extension is greater than the lateral extension of the vias 9 embedded in the substrate. An exemplary value of the lateral extension of a via 9 is 2 μm to 20 μm.
The optical configuration illustrated in FIG. 2 is a dark field configuration as illustrated by an angle β shown in FIG. 2 . The angle β is a minimum angle between rays 39 of measuring light 25 specularly reflected at the back surface 5 of the wafer and rays 41 of the portion of the measuring light scattered at the wafer 1 and received by the detector 31 . This minimum angle β is greater than 10°, 20° or 30°, for example.
Wavelengths of the light of the measuring beam 25 are selected to fulfil certain requirements illustrated below in more detail. For this purpose, transmissive filters allowing only certain wavelengths to traverse or reflective filters reflecting only certain wavelengths can be disposed in the beam path of the measuring light beam 25 . A same result can be achieved if the measuring light beam 25 includes a generally broad spectrum of wavelengths and wherein a wavelength selection is performed in the imaging beam path between the substrate 1 and the detector 31 by providing suitable transmissive or reflective filters. Moreover, the light source 21 can be configured such that it generates substantially only light from a desired wavelength range.
The portion 29 which is imaged onto the detector 31 may have a lateral extension such that plural through wafer vias 9 are located within the region 29 . The number of vias located within the region 29 may exceed 100 vias or many thousand vias. Still further, the lateral extension of the region 29 can be greater than a lateral extension of dice formed from the wafer 1 later by dicing. For example, the lateral extension of the region 29 can be selected such that it includes more than one, more than two, more than five or even more dice. Moreover, the region 29 imaged onto the detector 31 may include the full wafer 1 such that the lateral extension of the region 29 can be greater than 200 mm or greater than 300 mm depending on the diameter of the wafer 1 . An example of an optical configuration which can be used in optical methods illustrated in the present disclosure is illustrated in WO 2009/121628 A2, the full disclosure of which is incorporated herein by reference.
An alternative optical configuration which can be used in the optical methods illustrated in this disclosure is schematically shown in FIG. 3 . This setup includes a light source 21 a generating measuring light 23 a which is shaped to a focussed beam 25 a of measuring light by optics 27 a which may comprise one or more lenses and one or more mirrors. The focused beam 25 a of measuring light is directed onto a back surface 5 a of a wafer 1 a such that a lateral extension d 3 of the beam 25 at the back surface 5 a is greater than a lateral extension of through wafer vias 9 a embedded in the wafer substrate. For example, the lateral extension d 3 can be 2 times greater, 5 times greater, 10 times greater or even 100 times greater than the lateral extension of the through wafer vias 9 a.
The beam of measuring light 25 a is directed onto the substrate la under an angle α relative to a surface normal of the wafer 1 a.
A detector 31 a is positioned such that a minimum angle β of rays 39 a of measuring light 25 a specularly reflected at the back surface 6 a of the wafer and rays 41 a of the measuring light received by the detector 31 a is greater than 10°, 20° or 30°, for example.
The detector 31 a may include one single light sensitive element or a number of light sensitive elements. While it is possible that the detector 31 a is a position sensitive detector, this is not necessary in the illustrated configuration. An image of the wafer 1 a can be obtained by scanning the beam 25 a across the back surface 5 a of the wafer and recording light intensities detected with the detector 31 a in dependence of a position to which the beam 25 a is directed. For example, the wafer 1 a can be rotated and/or otherwise displaced relative to the beam 25 a of incident measuring light.
The optical configurations illustrated above with reference to FIGS. 2 and 3 are dark field configurations in which a main direction of measuring light originating from the wafer and received by the detector is oriented substantially parallel to a surface normal of the wafer. It is, however, possible to achieve dark field configurations also with optics in which the light originating from the wafer and received by the detector has a main direction oriented under an angle relative to the surface normal. It is, in particular, also possible to direct the incident measuring light substantially orthogonal onto the wafer surface. The dark field configuration is achieved by the minimum angle between rays of specularly reflected light and rays of detected light. The minimum angle β is in particular greater than 0° and preferable greater than 10°, 20° or 30° for example.
Other configurations of optics which can be used in the optical methods disclosed herein include bright field optical configurations in which there is an angular overlap between rays of measuring light specularly reflected off the surface of the wafer and rays received by a detector.
The inventors have found that optical configurations which are conventionally used for inspection of defects located on a surface of a substrate can also be used for detection of features embedded in the substrate and located at a residual distance from the surface of the substrate.
FIGS. 4 a , 4 b and 4 c show images obtained from a back side of a semiconductor wafer having embedded features. The substrate material of the semiconductor wafer is silicon, and the embedded features are through wafer vias made of copper. The three images shown in FIG. 4 are obtained at different residual distances of tip ends of the vias from the back surface of the wafer. In FIG. 4 a , the residual distance d 1 is 6 μm, and the features visible in the image mostly relate to grinding marks of a grinding tool used in the wafer thinning process. A number of image features which might be indicative of the presence of the through wafer vias is low.
FIG. 4 b shows an image of a wafer back side where the residual distance d 1 varies between 1 μm and 2 μm. The features visible in the image include grinding marks similar to those of FIG. 4 a , and patterns having a structure corresponding to an arrangement pattern of through wafer vias manufactured in the substrate. The features of the grinding pattern and the features of the via pattern are provided in the image with a similar contrast.
FIG. 4 c shows an image of the back side of the wafer in which the residual distance d 1 of the vias is less than or equal to 0.5 μm. It is apparent that the features corresponding to the arrangement of vias is even more prominent than in FIG. 4 b and that the features corresponding to the arrangement of vias have a higher contrast in the image than the features related to the grinding pattern.
From FIGS. 4 a , 4 b and 4 c it is apparent that an image contrast and/or image intensity of patterns contained in an image of a back side of a wafer is indicative of a residual distance between features embedded in the wafer and the back surface of the wafer.
The image contrast produced by features embedded in the substrate and located below the substrate surface can be enhanced by imposing restrictions to the measuring light used for the imaging. For example, it is desirable that light reflected at the front surface of the substrate or light scattered at structures provided on the front side of the substrate do not contribute to the detected image. Such light travels through the substrate material along a path having a length which is at least two times greater than the thickness of the substrate. Therefore, it is advantageous to select wavelengths of the measuring light contributing to the detected image such that a substantial extinction of measuring light occurs after a path length within the material greater than two times the thickness of the substrate. This can be achieved by selecting the wavelengths such that a penetration depth of the measuring light in the substrate material is smaller than 2.0 times, 1.0 times or 0.5 times a thickness of the substrate. In this context, the penetration depth is defined as the depth at which the intensity of the measuring light inside the substrate material falls to 1/e (about 37%) of the original value at the surface.
For example, if the substrate material is silicon and a thickness of the substrate can be as small as 10 μm, it is advantageous to use measuring light of wavelengths less than 900 nm, 850 nm, 800 nm or 750 nm, for example.
On the other hand, the measuring light used for generating an image of an arrangement pattern of features located below a back surface of a substrate should still have a significant intensity when it reaches the buried features. Therefore, it is advantageous to select the wavelengths of the measuring light such that a penetration depth of the measuring light in the substrate is greater than 0.2 times, greater than 0.5 times or greater than 1.5 times a residual distance between the buried features and the substrate surface.
In the example where the substrate material is silicon and where the buried features are through wafer vias made of metal, it is advantageous to use measuring light having wavelengths greater than 500 nm, greater than 550 nm, greater than 600 nm or even greater than 650 nm.
FIG. 6 shows experimental data of the penetration depth in μm of light in a silicon substrate material in dependence of the wavelength of the light in nm. It is apparent that a lower limit of the wavelength which can be used to detect features more than 1 μm below the surface should be greater than 500 nm, whereas wavelengths below 900 nm should be used to detect such features in a substrate having a thickness below 35 μm.
FIG. 5 is a graph of experimental data showing the dependency of the residual distance of the through wafer vias, as shown in FIG. 4 , in dependence of a dark field image intensity of arrangement patterns of the vias in the image. From this graph it is apparent that the dark field image intensity and contrast are well-suited to be indicative of the residual thickness.
Apart from the wavelengths, the measuring light used for detection can also be selected with respect to its polarization such that a high amount of the incident light enters into the substrate and/or such that the suitably polarized light generates a high image intensity or contrast.
The optical methods of inspection of a semiconductor wafer can be used for obtaining information used to control a wafer thinning process in mass production of semiconductor devices. Such manufacturing method is illustrated with reference to the flowchart shown in FIG. 7 below. The method includes bonding a first substrate to a second substrate wherein through wafer vias exposed at a back surface of the first substrate are contacted by the second substrate bonded to the first substrate. In a production of wafers, a next wafer is used for processing in a step 101 . Semiconductor structures and vias are formed on a front side of the wafer by lithographic processes and other processes in a step 103 . Thereafter, a carrier is attached to a frond side of the wafer, and a thinning process is applied to a back side of the wafer in a step 105 . The thinning process may include, for example, grinding and/or polishing. The thinning process is controlled by grinding parameters 107 , such as, among others, a number of revolutions per unit time of a grinding or polishing apparatus, a force applied between a grinding or polishing tool and the back side of the wafer or a duration of the grinding or polishing process. The grinding parameters are selected such that a residual thickness between tip ends of the through wafer vias and the back surface of the wafer is 2 μm. Thereafter the residual thickness or information indicative of the residual thickness is determined in a step 109 using optical methods as illustrated above. Based on the determined residual thickness or information indicative of the residual thickness, the control parameters 107 of the thinning process 105 and control parameters 111 of a subsequent thinning process 113 are updated in a step 115 . Thereafter, the further thinning process is applied to the back side of the wafer to expose the through wafer vias at the back surface of the wafer in the step 113 . Such final thinning process may include an etching which selectively removes substrate material and does substantially not remove the material of the through wafer vias. Also the thinning process of step 113 is controlled by process parameters 111 which may include, among others, a duration of the thinning process, a concentration, composition or temperature of an etching substance, or a plasma intensity applied in the thinning process.
A second substrate is bonded to the wafer in a step 115 after exposing the vias on the back surface. The second substrate may comprise a full wafer or individual dyes of semiconductor devices which have been selected according to suitable quality requirements.
Thereafter, a next wafer is processed at step 101 .
It is to be noted that the images obtained from the back surface of the wafer include also other features not related to the through wafer vias. These other features are, for example, generated by defects located on the surface of the substrate. Examples are the grinding marks visible in FIGS. 4 a , 4 b and 4 c. An analysis of such other features can provide information which can be used to control the processing of the wafer. For example the grinding marks can be indicative of a defect of the grinding apparatus used, such that the obtained information may trigger a repair of the grinding apparatus. Moreover, additional images can be obtained in an inspection step by recording one or more images using different wavelengths and polarisations of the measuring light used for imaging.
The information indicative of the residual thickness of the substrate obtained in step 109 can be used to update control parameters of a thinning process applied to the same wafer subsequently. Such process can be referred to as feed-forward control since it is based on information obtained from an individual wafer and is used for controlling further processing of the same wafer. The updating of control parameters of the thinning process applied to the individual wafer in step 105 is a feed-back control since it is effective only for a next wafer processed in a production line.
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A method of inspecting a semiconductor substrate having a back surface and including at least one piece of metal embedded in the substrate comprises directing measuring light towards the back surface of the substrate and detecting a portion of the measuring light received back from the substrate. The method also includes determining a distance between the piece of metal and the back surface based upon the detected measuring light received back from the substrate.
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TECHNICAL FIELD
The present invention relates to communication systems, and more particularly to synchronization of frequency hopping communication systems.
BACKGROUND ART
Frequency hopping is a radio communication technique in spread-spectrum modulation wherein information is transmitted using a sequence of carrier (or operating) frequencies that change at set times to produce a narrow band signal that bounces or hops around a center frequency over an available frequency spectrum.
In a centrally controlled multicellular mobile radio communication system based on slow frequency hopping, each cell has a base station that provides the necessary timing and control information received and used by all the remote stations that belong to the cell.
All stations belonging to a cell, the base station and all remote stations that belong to it, must hop in synchronism in order to communicate with each other at the same frequency. Different cells will typically operate on different frequency hopping patterns. The control information required for synchronized frequency hopping is broadcast by the base station. A key problem in the operation of a frequency-hopping based system is that of acquiring hop synchronization between one remote station and the base of a cell.
The following references are typical of the background art in the field of frequency hopping systems and synchronization techniques thereof.
U.S. Pat. No. 5,081,641 issued Jan. 14, 1992 to Kotzin et al. entitled "Interconnecting And Processing System For Facilitating Frequency Hopping" discloses a method and apparatus for facilitating communication of information in a system without the use of a baseband hopping unit, by sharing a common TDM bus between a plurality of radio communication units, processing units, and information links, where the processing units extract traffic channel information, packetize and/or unpacketize the information, and return same back to the common bus for retrieval by the information links or radio communication units.
In U.S. Pat. No. 4,850,036 issued Jul. 18, 1989 to Smith entitled "Radio Communication System Using Synchronous Frequency Hopping Transmissions" a frequency-hopping radio communication system is disclosed comprising a control unit which transmits to and receives from each of a plurality of slave stations using a frequency-hopping mode of operation. During a start-up mode, the control unit communicates a starting message to each slave station using a predefined frequency. The message identifies to each slave station a frequency-hopping sequence to be used to select the frequencies from a group of frequencies for transmission to and reception from the control unit. This message also specifies to each slave station unique starting frequencies in the frequency-hopping sequence at which to begin transmitting and receiving. All slave station transmission are synchronized to the control unit transmissions, thereby preventing any two stations from concurrently using the same frequencies for either transmitting to or receiving from the control unit.
EP 0658 023 A1 from IBM discloses a method for selecting a base station in a multicellular communication network system of the type having base stations and a plurality of remote stations. When a remote is first powered up it chooses randomly a frequency and searches for valid header messages from neighboring bases. After a fixed period of time which is equal to the length of a superframe (MAC protocol exchanges during the complete base station frequency hopping pattern) it randomly switches to another frequency and keeps on monitoring.
While the solutions of the prior art are efficient in their environment, they do not directly address the problem of shortening the procedure of radio environment listening. Moreover, the use of a signaling channel does not comply with the U.S. Federal Communications Commission (FCC) regulation in the 2.4 GHz Band, while the average and the maximum duration for selecting a base in the prior art does not comply with the fast base selection required for the actual hand-off systems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and structure for achieving reliable and fast base selection in a radio communication cell.
It is a further object of the present invention to allow a remote station to select a base with an acceptable average and maximum duration, enabling the possibility to have hand-off between cells.
It is another object of the present invention to provide a method that allows a remote station to scan rapidly a set of "n" frequencies upon the duration of a base station hop.
It is yet another object of the present invention to tailor the rapidity of the scanning to the minimum information density sent or received by a base station.
Accordingly, in the preferred embodiment of the invention, a method for attachment of a remote station to a base station in a multicellular communications network system is provided. The network comprises base stations and a plurality of remote stations, wherein the base stations and the remote stations comprise means for emitting frames of information using a sequence of changing frequency hops of different operating frequencies. The method for the attachment of a remote station comprises the steps of: determining a set of "n" operating frequencies (Fi), on each said frequency (Fi) sequentially listening for frames of information emitted by said different base or remote stations, said listening being for a fixed period of time equal to 1/n of the frequency hopping period (FH) of a base station, collecting and processing the information contained in a frame when a frame of information is received by one of said remote stations during one of the fixed period, and selecting a base station for attachment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a pictorial diagram showing a typical radio digital data communication system of the type in which the invention is implemented;
FIG. 1A shows a block diagram of the system shown in FIG. 1 illustrating the basic components of a mobile station and a base station as known in the art;
FIG. 2 shows a block diagram of the radio system used in the implementation of a preferred embodiment of the invention;
FIG. 3 is a diagram of the frame structure of the MAC protocol of the prior art;
FIG. 4 is an illustration of a flow chart of steps employed in the monitoring and selection phases of the synchronization technique of the prior art; and
FIG. 5 is an illustration of a flow chart of steps employed in the monitoring and selection phases of the synchronization technique of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, there is shown a typical radio system allowing communication between a plurality of mobile stations 10, 12, 14, and 16 and applications and data residing in a computing system. The computing system typically includes a Wireless Network Manager (WNM) or Wireless Network Controller 18, with attached monitor 20 and keyboard 22, of a local area network (LAN), generally indicated by reference numeral 24, having a plurality of attached workstations or personal computers (not shown for simplicity). Also attached to the LAN are one or more gateways 26 and 28 with which the mobile stations 10, 12, 14, and 16 communicate. These gateways, referred to as base stations, are augmented according to the invention to provide certain radio system management functions which coordinate the mobile stations' access to the common radio channel. Communications between mobile stations is supported via relay through the base stations 26 and 28.
As shown in more detail in FIG. 1A, a base station 26 or 28, which may be a conventional microcomputer, has a LAN adapter 30 inserted in a bus slot and connected to LAN cabling 32. The WNM 18, typically also a conventional microcomputer and including one or more direct access storage devices (DASDs) such as hard disks (not shown), also has a LAN adapter 34 inserted in a bus slot and connected to LAN cabling 32. The LAN adapters 30 and 34 and LAN cabling 32 together with LAN software constitute the LAN 24. The LAN 24 is of conventional design. The base station 26 or 28 also has an RF transceiver adapter 36 implemented as a printed circuit card which is inserted in a bus slot of the base station. The transceiver adapter 36 includes a spread spectrum transceiver of conventional design. The transceiver adapter 36 has an antenna 38 by which a radio link 40 is established with one or more remote or mobile stations, 10, 12, 14, or 16. The mobile station may itself be a hand held or lap top computer of conventional design and, like the base station, it is provided with an antenna 42 and a transceiver adapter 44, also implemented as a printed circuit card which is inserted in a bus slot of the computer. The transceiver adapter 44, like transceiver adapter 36, includes a spread spectrum transceiver of similar design. The base station and the mobile stations are further provided with software, generally indicated by reference numerals 46 and 48, respectively, which support their respective transceiver adapters.
FIG. 2 shows the radio system common to both the mobile stations and the base stations of FIG. 1. The radio system includes a transceiver adapter 36 or 44 connected to the computer 50 via the computers bus interface 52. The transceiver station is itself divided into an RF transceiver 54, which may be a commercially available spread spectrum transceiver, and a dedicated microprocessor system 56 which controls the transceiver via an interface 58. The microprocessor system 56 further includes a system interface 60 which interfaces the transceiver section to the computer section 50. The microprocessor system includes a dedicated microprocessor 62 containing high-resolution time interval determination hardware or "timers" typical of real-time microprocessor systems.
Microprocessor 62 is connected by a memory bus 64 to program storage 66 and data storage 68 as well as to interfaces 58 and 60 providing attachment to bus interface 52 and RF transceiver 54, respectively. Program storage 66 is typically read only memory (ROM), while data storage 68 is static or dynamic random access memory (SRAM or DRAM). Packets received or to be sent are held in data storage 68 and communicated to or from the RF transceiver 54 via interface 58 under control of serial channels and a direct memory access (DMA) controller (not shown) which is part of the microprocessor 62. The function of these serial channels is to encapsulate data and control information in an HDLC (high-level data link control) packet structure and provide the packet in serial form to the RF transceiver 54. For more information on the HDLC packet structure, see, for example Mischa Schwartz, Telecommunication Networks: Protocols, Modeling and Analysis, Addison-Wesley (1988).
When a packet is received through the RF transceiver 54, the serial channels check the packet destination address, check for errors, and deserialize the packet to data storage 68. The serial channels must have the capability to recognize a specific adapter address as well as a broadcast address. Specific microprocessors with appropriate serial channel and timer facilities include the Motorola 68302 and the National HPC46400E microprocessors.
The computer 50 runs an operating system 70 which supports one or more user application programs 72. The operating system 70 may include a communications manager 74, or the communications manager 74 may itself be an application program installed on the computer. In either case, the communications manager 74 controls a device driver 76 via the operating system 70. The device driver 76, in turn, communicates with the transceiver adapter 36 or 44 via bus interface 52.
Referring now to FIG. 3, a variable length time frame structure which consists of interleaved A, B and C type time slots along with frame and frequency hopping headers is described. The structure and length of the frame is traffic dependent, all frames start with a header packet SH which describes the structure of the frame, followed by interleaved sequences of contiguous type A, type B or type C time slots, each sequence of contiguous time slots of the same type being designated as a period. During A time slots the radio link is used exclusively for outbound data transfer from the base station to remote stations and acknowledgments in the reverse direction. Both control and data outbound traffic occurs within A slots. During B slots the radio link is used exclusively for reservation-based inbound data transfer from the remote stations to the base station and acknowledgments in the reverse direction. Only inbound data traffic occurs within B slots. In a preferred embodiment of the invention, during C slots the radio link is used for contention based inbound data transfer from remote stations to the base station and acknowledgments in the reverse direction. However the person skilled in the art can easily devise other arrangements in which type C slots are used for direct communication between remote stations without using the base station as a relay. Both control and data traffic may occur within C slots. A and B time slots have the same duration which is equal to twice the duration of a C slot. In a preferred embodiment of the invention type C time slots are always grouped by pairs and will be referred to as C pairs. Slot allocation is performed by a scheduler resident in the base station adapter 26 or 28 in FIG. 1A. Time slots are allocated in each time frame for inbound and outbound transfers according to instantaneous traffic conditions, the time frame duration is variable as can be seen from the examples of time frames shown in FIG. 3 (time frame 0 to time frame 6). Each line in FIG. 3 (80, 81, 82, 83) represents a frequency hop time period. Hop header (HH) is sent before switching from the current frequency to the next one in the hopping pattern. It is used by registering remote stations to select a base station. Frequency header (FH) is sent after the frequency has been switched. It is used for synchronization between the base station and remote stations and for hopping pattern tracking, it also provides traffic information for power saving purposes. Slot header (SH) is sent at the beginning of each time frame, it carries traffic information representative of the structure of the time frame describing the sequence of interleaved type A, type B and type C periods to come. Each period being defined by its type A, B or C, the number of slots and the destination and source address of the slots. In a particular embodiment of the invention source and destination addresses can be used for type C slots allocated for direct transmission between two remote stations without using the base station as a relay.
Referring now to the first frequency hop 80 in FIG. 3, it shows the last portion of time frame 0 which consists in 4 type A slots for outbound traffic followed by 1 type C pair for contention-based inbound data and control traffic, 3 type B slots for reservation based inbound data traffic and again 2 type C pairs. It is assumed that the SH header corresponding to time frame 0 was sent during the previous frequency hop not represented in this figure. Time frame 1 (TF1) follows, it starts with a SH header, followed by two type C pairs. This time frame type represents the longest possible inactivity period during which no traffic occurs. The structure of time frame 2 is identical to time frame 1. Time frames 1 and 2 are illustrative of the traffic sent by an idle base station. Time frame 3 comprises 3 type B slots dedicated to reservation based inbound traffic followed by two type C pairs. This is the kind of traffic experienced when there is no outbound message from the base station to the remote stations. Time frame 4 spills over a frequency hop boundary represented by the HH/FH headers sequence at the beginning of the second frequency hop 81 in FIG. 3. Time frame 4 consists in a SH header followed by 9 type A slots, 1 type C pair, 6 type B slots and 2 type C pairs. The HH/FH headers sequence is inserted after the 5 first type A slots of time frame 4 to reserve time for frequency hopping. Time frame 5 spills over two frequency hop boundaries represented by the HH/FH headers sequences at the beginning of the third and fourth frequency hops 82 and 83, it comprises 16 type A slots, followed by one type C pair, 8 type B slots, 1 type C pair, 14 type A slots, 1 type C pair, 9 type B slots and 2 type C pairs. Both time frame 4 and 5 are representative of a fairly to highly loaded traffic. They show how a time frame may extend over two or more frequency hops. In addition time frame 5 shows how different types of slots can be interleaved in the same time frame. It should be noted that the HH and FH headers are transmitted on a cyclic basis corresponding to the fixed frequency hopping period THOP, whereas the SH headers are sent at a pace depending on traffic conditions.
This protocol assures that the maximum inactivity duration is five slots long, and that a listening remote station is sure to get any kind of packet from a station within six slots, if the remote station listens on the same frequency.
In the preferred embodiment of the invention the duration of the various headers, slots and hops is as follows:
HH and FH headers: 2 milliseconds (ms)
SH header: 4 ms
A and B slots: 4 ms
C slots: 2 ms
FH period: 96 ms
For the clarity of the description, the different parameters used to achieve the invention are: Thop is the duration of the FH period, N is the number of frequencies in the hopping pattern of the base station (N>78 according to FCC regulation in US), the duration of the superframe is the time during which the base station scans its hopping pattern, Fr is the set of frequencies that the remote station (mobile station) listens to during the radio environment listening, n is the number of frequencies in the Fr set.
Referring to FIG. 5, the initial pattern acquisition steps are shown. When a remote is first turned on, it does not know which are the surrounding bases and what frequency hopping patterns they have. However, it is assumed that it knows both the hop length and the superframe length. A remote depends on executing the algorithm shown in FIG. 5 in selecting its home base.
The flow diagram of the process is performed by the microprocessor system 56 of the transceiver adapter 44 of a registering mobile station 8 listening to its radio environment when it is first opened. It first receives, as depicted in function block, a transceiver adapter opening request from computer 50 via the computer bus interface 52. This opening request comprises a network identifier NETid of the logical network to register in. The microprocessor system 56 of registering mobile station 8 stores NETid in Data Storage 68 (step 420). It is assumed that registering mobile station 8 wants to register in a logical network comprising network cell 2 owned by base station 28 as depicted in FIG. 1. The mobile station 8 in step 420 sets two variables (i,j) to zero, wherein "i" is the index for the set of frequencies Fr used by the mobile station, while "j" is the number of frequency switches done by the mobile station. In function block 430, mobile station 8 switches to a frequency Fi, out of a set of "n" fixed operating frequencies, among predetermined frequencies selected according to U.S. Federal Communications Commission (FCC) in its regulations part 15.247. The index "i" and the variable "j" are incremented. In step 440, the mobile station 8 starts a timer during the listening duration of frequency Fi, and which is THOP/n. In next step 450, registering mobile station 8 listens to receive a packet in any type of time slots (FH,HH,SH,A,B,C), which is sent by any station (base or remote) in the cell. Upon receiving this packet, registering mobile station 8 waits for the occurrence of a header section (FH) and checks, that the network identifier NETid of the base station matches the network identifier NETid stored in Data Storage 68, as depicted in step 460. If it does not match, the registering mobile station 8 ignores this base station and keeps listening to the selected frequency Fi (step 450) until it receives another header section or until the end of the timer duration (THOP/n). If the network identifier NETid of the received header section corresponds to the NETid stored in Data Storage 68, registering mobile station 8 checks in step 470 if the base station address carried by the header section (FH) is an element of a list of owner base stations which are candidates identified during previous frequency iterations. If it is already recorded, it means that the same base station was previously found while listening to the registering mobile station radio environment, therefore the process loops back to step 450 and registering mobile station 8 keeps listening to the same frequency Fi until it receives another header section or until the end of the timer duration. If the base station identifier was not previously found, function block 480 is performed. Registering mobile station 8 checks if the strength of the signal received (RSSI) from the base station is greater than a given threshold, and checks if the number of mobile stations connected to this base station is not too high (compared to a given Load factor LF) in order not to overload the cell. If these two criteria are met (branch YES), the operation of the base selection of step 510 consists in selecting this last base station as the home station. If the result of the test is NO (one of the two or both criteria not met) then, on step 490, the base address, the strength of the received signal and the number of the mobile stations connected are stored in a Data Storage 68. On next step 500, the value of "j" is checked. If it is equal to "n×N", which means that the duration of the entire process has exceeded the length of the superframe, then the base selection process 510 is performed. If "j" is not equal to "n×N", then the process loops back to step 450, and mobile station 8 keeps listening to the same frequency Fi until it receives another header section or until the end of the timer duration. The efficiency of this method is directly related to the value of parameter "n". In fact, for a high value of "n", i.e. many frequencies selected for the set Fr of frequencies, the mobile station is scanning these frequencies in a short period of time which is THOP/n, and therefore the probability to hear a base station is increased. But there is a top limitation for the value of "n" which is linked to the minimum density of information transmitted or received by the base. For instance, in the preferred embodiment of the invention, the minimum density of information is one information every six slots, as showed in FIG. 3 on Time Frame 1. Succession of several time frames of the type Time Frame 1 in FIG. 3 represents the minimum density of information on a longer period. In this case, the succession of time slots is the following: SH CC CC SH CC CC SH CC CC . . . etc. SH is 2 time slots long and comprises one information (the SH packet) and all the CC maybe empty if the remote stations attached to the cell do not need to communicate with the base stations. Therefore the mobile station must stay six slots on the same frequency to hear an information coming from any station in the cell. In this case, with 48 slots in a FH period, the parameter "n" is then equal to 8 frequencies.
In another embodiment, in order to prevent mutual interferences between cells, the choice of the hopping pattern of the base station is not done randomly, but follows a general formula known to a skilled person in the art, and which is:
First base frequency F(1)=1
Th. base frequency F(i)=F(i-1)+C mod<N>, wherein C is a prime number greater or equal to seven, and wherein N is the length of the hopping pattern.
For the clarity of the description, the following example will illustrate the case with C=7 and N=79:
F(1)=2401 MHz
F(2)=2408 MHz
F(3)=2415 MHz, etc. . . .
In this environment, the choice of the "n" frequencies that the remote station listens to, is tuned to achieve a better radio environment listening. In that way, some sets Fr leading to degraded radio environment listening, are prohibited such as a set of "n" consecutive frequencies. One advantage of this embodiment is to avoid the choice of a potentially polluted frequency such as microwave oven frequency.
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In a multicellular communications network system comprising base stations and a plurality of remote stations, a remote station listens for frames of information emitted by the different base or remote stations, in order to insert the network. The base stations and the remote stations comprise means for emitting the frames of information using a sequence of changing frequency hops of different operating frequencies. The remote station determines a set of "n" operating frequencies (Fi), from which it sequentially listens for a fixed period of time equal to 1/n of the frequency hopping period (FH) of a base station. When a frame of information is received by the remote station during one of the fixed period, the information is collected and processed in order to select the base station for attachment.
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PRIORITY INFORMATION
[0001] The present application is a continuation application of U.S. patent application Ser. No. 13/247,932, filed Sep. 28, 2011, which claims priority under 35 U.S.C. §120 to U.S. Provisional Patent Application No. 61/387,388, filed Sep. 28, 2010, the entire contents of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTIONS
[0002] 1. Field of the Inventions and
[0003] The present inventions relate to improvements in high speed production sheeting devices for comestible products (e.g., tortillas and tortilla chips). More specifically, the present inventions relate to sheeting devices which control the spacing of rollers used to roll a comestible product to a desired thickness.
[0004] 2. Description of the Related Art
[0005] Corn tortillas and tortilla chips are cut from a sheet of corn dough, called “masa,” and then baked and/or fried. In mass production, the sheeting and cutting stages are accomplished by a tortilla sheeter.
[0006] High production tortilla sheeters feed masa from a hopper between a pair of large, stainless steel rollers which roll the masa into a sheet of substantially uniform thickness. The rollers are spaced apart in production to form a gap, known as a “pinch point gap,” through which the masa passes. The masa adheres to the surface of one of the rollers, known as the exit roller, after passing through the pinch point gap. A third roller then cuts the masa into either tortillas or tortilla chips. The third roller, known as the cutting roller, commonly has either circular shaped (for tortillas) or triangular-shaped (for tortilla chips) cutting guides positioned on the cylindrical external surface of the cutting roller. The cut tortillas or chips then are stripped from the exit roller by a wire and/or a blower, or by a similar device.
[0007] High production tortilla sheeters automate virtually every step of the sheeting and cutting process. One challenge that remains, however, is to accurately control the thickness of the masa sheet before cutting.
[0008] The consistency of corn masa commonly varies over time depending upon humidity, temperatures, granularity, and other known factors, and occasionally will contain hard kernels of corn. If the distance between the sheeting rollers is rigidly fixed, the thickness of the exiting masa sheet will change depending on the masa consistency. The consistency of the masa can also vary within the hopper, and, thus, vary across the length of the sheeting rollers. As a result, the thickness of produced tortillas or chips undesireably varies.
[0009] Prior sheeting devices included computer controlled motors driving jack screws to guide one of the rollers along a linear path to thereby control the size of the pinch point gap. For example, FIGS. 1 and 2 illustrate such a known sheeting device.
[0010] With reference to FIG. 1 , the known sheeting device 10 includes a roller component 14 and a drive component 16 . A lower housing 18 houses the drive component 16 . The drive component 16 includes a conventional electric motor (not shown) which drives the roller component 14 via a series of common gears and chains or belts (not shown), as known in the art. A conventional pneumatic control system controls the pneumatic devices of the sheeting device 10 (e.g., a stripping wire 44 and a cutting roller 38 ).
[0011] The roller component 14 rests on, or is attached to, the top of the lower housing 18 and includes a hopper 22 positioned above a pair of counter rotating rollers 24 , 26 . The front roller 24 and the rear roller 26 are generally cylindrical. The rollers can also have a roughened surface (obtained, for example, with sandblasting). The rollers 24 , 26 desirably rotate at the same speed; however, it is understood that the rollers 24 , 26 can rotate at different speeds if required by specific application.
[0012] The rollers 24 , 26 are positioned parallel to each other and, as shown in FIG. 2 , define a pinch point 28 , i.e., the point at which the rollers 24 , 26 contact or nearly contact each other. In operation, the rollers 24 , 26 are spaced slightly apart to form a gap between the surfaces of the rollers 24 , 26 at the pinch point 28 .
[0013] With continued reference to FIG. 2 , the hopper 22 is positioned above the rollers 24 , 26 so as to contain masa 30 between the rollers 24 , 26 . As noted above, the term “masa” is used to denote a corn dough which is commonly used to form tortillas and tortilla chips. However, this type of sheeting device 10 can be used with other types of comestible products, such as, for example, grain-based doughs or doughy-like food mixtures.
[0014] The rear roller can be adjusted relative to the front roller to thereby vary the spacing between the rollers 24 , 26 , i.e., to vary the spacing of the size of the pinch point gap 28 . Thus, as is known in the art, this type of sheeting device 10 includes an electric motor-driven jack screw arrangement 38 which allows the roller 26 to be slid along the axis 32 toward and away from the roller 24 .
[0015] More specifically, as shown in FIG. 2 , the rear roller 26 rotates about an axis defined by the axle 34 . A movable bearing plate 36 supports one end of the axle 34 and another bearing plate (not shown) supports the opposite end of the axle 34 . Each of the bearing plates 36 rides in a track (not shown) supported by the frame 39 . A jack screw 38 is connected to each bearing plate 36 to move the corresponding bearing plate within the track.
[0016] The axis of the track, which defines the slide axis 32 , is aligned with the longitudinal axes of both rollers 24 , 26 and through the pinch point 28 . Thus, movement of the bearing plates 36 within their tracks moves the rear roller 26 relative to the front roller 28 to vary the size of the pinch point gap 28 .
[0017] This type of sheeting device 10 also includes a controller 54 which, through the use of various sensors, controls the jack screw drive to maintain the desired thickness of the masa 42 exiting the sheeting device 10 .
SUMMARY OF THE INVENTIONS
[0018] An aspect of at least one of the embodiments disclosed herein includes the realization that the type of sheeting device described above with reference to FIGS. 1 and 2 can suffer from excessive movements of the various components forming the jack screw drive assembly. For example, elastic deformations of the screw itself, due to its length, can cause significant displacements of the roller as the forces produced by the masa changes. Additionally, the other bearings and joints requiring lubrication clearances can also contribute to unintended movements of the rollers during operation. These movements can be as great as 2/10,000 ths of an inch (0.0002 inches) every 20 seconds, or more. Although the system described above is actively controlled to adjust the thickness in response to these changes, the adjustments do not eliminate waste or unacceptable product discharged from the sheeter. Rather, even with the computer controlled thickness adjustment system included in the above-described sheeter 10 (as described in U.S. Pat. No. 5,470,599) there is a continuous stream of unacceptable product discharge from the sheeter due to unintended movement of the rear roller 26 .
[0019] An aspect of at least one of the embodiments disclosed herein includes the realization that an eccentric pinch point adjustment system can eliminate several of the mechanical joints necessary for a jack screw drive and thereby reduce unintended movements of a roller of a sheeting device.
[0020] Thus, in accordance with at least one embodiment disclosed herein, a rolling device can include a support housing, a first roller having a first outer surface and supported by the first housing to rotate about a first axis, and a second roller having a second outer surface and supported by the housing to rotate about a second axis spaced from the first axis such that juxtaposed portions of the first and second outer surfaces define a pinch point gap. The roller device can also include at least a first pinch point gap adjustment mechanism comprising a rotatable roller mounting plate supported by the housing so as to be rotatable about a third axis and a mount supporting the first roller such that the first axis is offset from the third axis, thereby causing the first axis to revolve about the third axis when the roller mounting plate is rotated about the third axis and thereby changing a magnitude of the pinch point gap.
[0021] In accordance with another embodiment, a rolling device can comprise a support housing, a first roller having a first outer surface and supported by the first housing to rotate about a first axis, and a a second roller having a second outer surface and supported by the housing to rotate about a second axis spaced from the first axis such that juxtaposed portions of the first and second outer surfaces define a pinch point gap. Additionally, the rolling device can include a first pinch point gap adjustment means for revolving the first axis about a third axis spaced from the first axis and changing a magnitude of the pinch point gap.
[0022] In accordance with yet another embodiment, a method of adjusting a spacing of two rollers can comprise supporting a first roller so as to rotate about a first axis, supporting a second roller so as to rotate about a second axis spaced from the first axis such that juxtaposed portions of outer surfaces of the first and second rollers define a pinch point gap, and revolving the first roller such that the first axis revolves about a third axis spaced from the first and second axes thereby changing a magnitude of the pinch point gap.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above-mentioned and other features of the inventions disclosed herein are described below with reference to the following drawings. The illustrated embodiments of the sheeter are intended to illustrate, but not to limit, the inventions.
[0024] FIG. 1 is a top, front, and right side perspective view of a prior art sheeting device;
[0025] FIG. 2 is an enlarged and partial right side elevational view of the prior art sheeting device of FIG. 1 ;
[0026] FIG. 3 is a schematic representation of an eccentric adjustment device which can be used with any of the embodiments disclosed herein;
[0027] FIG. 4 is a schematic diagram of two rollers of a sheeting device in which one of the rollers is adjustable with the eccentric adjustment device of FIG. 3 .
[0028] FIG. 5 is a top, front, and right side perspective view of a sheeting device in accordance with an embodiment;
[0029] FIG. 6 is a left side elevational view of the sheeting device of FIG. 5 ;
[0030] FIG. 7 is an enlarged, front, top, and left side perspective view of a roller drive of the sheeter illustrated in FIG. 6 ;
[0031] FIG. 8 is a bottom, front, left side perspective, exploded view of the roller drive of FIG. 7 ;
[0032] FIG. 9 is an enlarged and partial right side elevational view of the sheeter device of FIG. 5 ;
[0033] FIG. 10 is a right side elevational view of the sheeter device illustrated in FIG. 9 , with an eccentric drive cover removed;
[0034] FIG. 11 is a rear, top, and right side perspective view of the eccentric drive mechanism illustrated in FIG. 10 ;
[0035] FIG. 12 is an exploded view of some of the components of the eccentric adjustment mechanism illustrated in FIG. 12 ;
[0036] FIG. 13 is a further exploded view of a portion of the eccentric adjustment mechanism illustrated in FIG. 12 ;
[0037] FIG. 14 is a sectional view of a portion of the eccentric drive mechanism of FIG. 13 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] The inventions disclosed herein have applicability to sheeters used in conjunction with continuously moving conveyor systems. However, an understanding of the inventions disclosed herein is facilitated with the following description of the application of the principles of the present inventions to dough rolling, and in particular, rolling dough into tortillas and tortilla chips. In some embodiments, the inventions disclosed herein can be used in conjunction with sheeters that have a sheet thickness control system, such as that disclosed in U.S. Pat. No. 5,470,599, the entire contests of which is hereby incorporated by reference. In particular, in some embodiments, the eccentric pinch point adjustment devices and the associated methods of operation disclosed herein can be used in place of the jack-screw type thickness adjustment hardware disclosed in U.S. Pat. No. 5,470,599, while using the same control system electronics, including the controllers, sensors, etc. as that disclosed in U.S. Pat. No. 5,470,599, or other similar control systems.
[0039] With reference to FIG. 3 , an eccentric mechanism 100 which can be configured to adjust a pinch point gap between rollers, can include a shaft mount 102 rotatably mounted within a frame 104 . The shaft mount 102 can be in the form of a circular and rotatable member having a shaft aperture 106 .
[0040] In the illustrated embodiment, the shaft mount 102 is rotatable about its center axis 108 relative to the support frame 104 . In an initial position of the shaft mount 102 , a center 110 of the aperture 106 is in an initial position. However, as the mount 102 is rotated clockwise relative to the frame 104 , the center 110 of the aperture 106 also moves clockwise. Similarly, when the mount 102 is rotated counter-clockwise, the center 110 of the aperture 106 also moves counter-clockwise.
[0041] With reference to FIG. 4 , the eccentric adjustment device 100 is illustrated as adjusting a magnitude of a pinch point gap between two rollers of a comestible product sheeter. For example, FIG. 4 schematically illustrates the rollers 124 , 126 of a comestible product sheeter. In the illustrated embodiment, the roller 124 rotates about an axis 128 . The axis 128 can be defined by fixed bearings and an axle (not shown), or it can be mounted so as to be movable. Such bearings can serve as a support configured to allow the roller 124 to rotate about the axis 128 .
[0042] The roller 126 can be mounted with bearings and an axle so as to rotate about axis 130 . Additionally, in the illustrated embodiment, the axle of the roller 126 can be mounted to an eccentric adjustment device, such as the eccentric adjustment device 100 illustrated in FIG. 3 .
[0043] When the adjustment device 100 is adjusted such that the axles 128 and 130 are closest to each other, the pinch point gap 132 between the rollers 124 , 126 is at its smallest magnitude, i.e., the rollers 124 , 126 are at their closest possible position.
[0044] When the mount 102 is rotated counter-clockwise over an angle θ, the axis of rotation 130 of the roller 126 also moves counter-clockwise over an angle θ about axis 108 . In this position, the pinch point gap grows to a larger pinch point gap 134 , based on the radius R and the angle θ. Thus, by controlling the rotation of mount 102 , the size of the pinch point gap 132 can be controlled.
[0045] FIG. 5 illustrates an embodiment of a comestible product sheeter 200 including an eccentric pinch point adjustment mechanism. The illustrated comestible product sheeter 200 includes a roller assembly 202 supported above a housing 204 . The housing 204 can house electronics, power connections, components of a control system, etc. In the illustrated embodiment, the housing 204 is wheeled for convenient placement and servicing.
[0046] The roller system 202 can include a hopper 206 positioned above a pair of counter-rotating rollers 208 , 210 . The rollers 208 , 210 can be generally cylindrical. In some embodiments, the rollers 208 , 210 have a slightly roughened surface (obtained, for example, by sandblasting). The rollers 208 , 210 can be driven at the same speed; however, the rollers 208 , 210 can also be rotated at different speeds depending on the desired effect and application.
[0047] The rollers 208 , 210 are generally positioned parallel to each other so as to define a pinch point therebetween, as described above with reference to FIG. 4 . In some embodiments, the rollers 208 , 210 can be mounted and sized such that, in their original or “brand new” state, the outer surface of the rollers 208 , 210 would contact each other and/or interfere with each other if the adjustment mechanism used to adjust the position of the rotational axis of the roller 210 were set at its minimum pinch point gap position. This can be particularly advantageous because, over time, the outer surfaces of the rollers 208 , 210 will become deformed and/or wear away. As such, the rollers 208 , 210 may be removed from the sheet device 200 to be resurfaced. When the rollers 208 , 210 are resurfaced, the diameters of the rollers 208 , 210 are reduced. Thus, by mounting the rollers 208 , 210 such that they would interfere with each other were they positioned in the minimum pinch point gap position, the pinch point gap adjustment mechanism can accommodate the smaller size of the rollers 208 , 210 after resurfacing yet still achieve the desired magnitude of the pinch point gap.
[0048] With reference to FIG. 6 , the hopper 206 can be configured to contain masa (corn-based dough) between the rollers 208 , 210 . As noted above, the term “masa” is used to refer to a corn dough which is commonly used to form tortillas or tortilla chips. However, it is understood that the present sheeter device 200 can be used with other types of comestible products, such as, for example, grain-based doughs, doughy food mixtures, or other substances.
[0049] A drive system for the roller 208 can be disposed in the housing 204 . FIG. 6 illustrates a drive cover 210 which covers the drive system for the roller 208 . Such a drive system can be configured in any known manner.
[0050] In the illustrated embodiment, the roller 210 is mounted to as to be movable relative to the roller 208 . More specifically, the rotational axis of the roller 210 can be moved relative to the rotational axis of the roller 208 , described in greater detail below.
[0051] The drive system 212 for the roller 210 can be constructed using any known motor, such as stepper motors or server motors, and gear reduction drives. With reference to FIGS. 7 and 8 , the drive system 212 can include an electric motor 214 and a gear reduction drive 216 . The gear reduction drive 216 can be mounted directly to an axle 218 of the roller 210 . In this arrangement, the drive system 212 thus moves as the position of the axle 218 is moved, described in greater detail below. Thus, in the illustrated embodiment, the drive 212 is connected to a portion of the housing 204 with a linkage assembly 220 . The linkage assembly 220 prevents the drive system 212 from rotating relative to the housing 204 , and thus ensures proper transference of rotational energy from the motor 214 to the axle 218
[0052] With reference to FIG. 9 , the sheeter 200 can also include two support plates 242 , 244 located at opposite sides of the housing 204 . FIG. 9 includes a right side elevational view of the plate 242 . The plates 242 , 244 support both of the rollers 208 , 210 , as well as other devices.
[0053] The plate 242 can be made from any desired material. It is most common in the food industry to use stainless steel for all components that will come into contact with any food product. Additionally, the illustrated embodiment is designed to roll masa. As such, the plates 242 , 244 should be designed to withstand approximately 10,000 pounds of force each. In practice, during operation, a sheet such as the sheeter 200 can experience loads of about 15,000 pounds between the rollers, i.e., the masa being squeezed between the rollers 208 , 210 experts about 15,000 pounds of pushing force pushing the rollers 208 , 210 away from each other. Thus, the plates 242 , 244 , in some embodiments, can be made from stainless steel of a thickness of about 1″ or greater.
[0054] The adjustment drive system 240 can include an electric motor 242 and a gear reduction device 243 . The gear reduction device can be used to drive a chain drive mechanism covered by a chain drive cover 246 . In some embodiments, the sheeter 200 can include to adjustment drive systems located at opposite ends of the roller 210 . However, in the description set forth below, only one adjustment drive system 240 is described. It is to be understood that in some embodiments, an identical adjustment drive system 240 can be disposed at the opposite end of the roller 210 .
[0055] With reference to FIGS. 10 and 11 , the chain drive cover 246 has been removed exposing the chain drive assembly 248 . The chain drive assembly 248 can include a drive spur 250 , a drive chain 252 , and a driven spur 254 . In the illustrated embodiment, the drive 248 is a double chain arrangement. Thus, the drive spur 250 has two sets of teeth in the form of a double spur, there are two chains 252 , and the driven spur 254 has two sets of teeth just as the drive spur 250 . As shown in FIG. 10 , the rotational axis 260 of the driven spur 254 is offset from the rotational axis 262 of the roller 210 .
[0056] In some embodiments, a position tab 264 can be mounted on the driven spurs 254 to aid in sensing a rotational position of the driven spurs 254 . For example, in some embodiments, proximity sensors or other types of sensor can be mounted to a sensor bracket 266 so as to detect the presence of the position tab 264 and thus provide a means for an associated control system to determine the rotational position of the drive spur 255 . Other sensors can also be used, such as any of those disclosed in U.S. Pat. No. 5,470,599, or any other sensors.
[0057] FIGS. 12 and 13 illustrate exploded views of the eccentric drive assembly for changing the spacing of the rotational axis 262 of the roller 210 relative to the rotational axis 269 and of the roller 208 . FIG. 14 illustrates a cross-sectional view of the eccentric drive assembly in an assembled state and.
[0058] With continued reference to FIGS. 12 , 13 , and 14 , the roller 210 includes an axle 270 . The axle 270 is supported by a bearing 272 , which can be in the form of a roller bearing unit. The outer surface of the bearing 272 is designed to rest within an eccentric adjustment plate 274 . As illustrated in FIG. 13 , the inner bore of eccentric adjustment plate 274 has an axis that is offset from the axis of the outer surface of the eccentric adjustment plate 274 .
[0059] The outer surface of the eccentric plate 274 is designed to fit within the bearing sleeve 276 . Retaining plates 278 , 280 secure the bearing 272 , eccentric plate 274 , and the sleeve 276 within a u-shaped recess 282 formed in the plate 242 .
[0060] With reference to FIG. 12 , the plate 242 also includes a removable journal 290 . With the journal 290 inserted into the u-shaped recess 282 , the retaining plates 280 and 278 can be bolted to each other, through a series of bolt holes provided around the u-shaped recess 282 and the journal member 290 . As such, as shown in FIG. 14 , the retaining plates 278 , 280 and the journal 290 are all fixed relative to the plate 242 .
[0061] An additional eccentric drive plate 294 can also be partially journaled within the inner bore 296 of the eccentric plate 274 . Additional bolts can be extended through the bolt hole patterns in the driven spurs 254 , retaining ring 298 , the eccentric drive plate 294 and the eccentric plate 274 . As such, the driven spurs 254 are rotationally coupled with the eccentric plate 274 . Thus, as the drive spurs 254 are rotated, the bearing 272 and thus the axle 270 of the roller 210 revolve along a circular path about the axis 260 , thereby changing the spacing between the rotational axis 262 relative to the rotational axis 269 of the roller 208 , and thereby change the spacing between the outer surfaces of the rollers, i.e., the “pinch point gap”.
[0062] As noted above, the sheeter device 200 can include a control system configured to control the speed of the rollers 208 , 210 , as well as the roller spacing drive system 248 . Such a control system can include various sensors, feedback control system components, actuators, and user interface devices. Such a control system is disclosed in U.S. Pat. No. 5,470,599 which is hereby expressly incorporated by reference. For example, such a control system can include a controller device and at least one sensor configured to detect a magnitude for the pinch point gap. The controller device, can be configured to drive the adjustment drive system 240 so as to adjust the detected size of the pinch point gap, as detected by the sensor, to a desired magnitude, which can be input into the controller device by a user. Such a configuration and programming of the controller device is within the skill of one of ordinary skill in the art, in light of the disclosure above and that set forth in U.S. Pat. No. 5,470,599.
[0063] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.
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A thickness control system for a high speed tortilla sheeting machine can adjust a pinch point gap between a pair of sheeting rollers to maintain a generally uniform thickness of the produced “masa” (i.e., corn dough) sheet. The sheeting machine can include a pinch point gap adjustment device which guides at least one of the rollers through an arcuate path to thereby adjust a magnitude of the pinch point gap. The controller can direct one or more actuators to change the position of the roller along the archive path to thereby change the distance between the two sheeting rollers as desired to produce a masa sheet at the desired preset thickness.
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.Iadd.This is an application for reissue of U.S. Pat. No. 4,872,399 granted Oct. 10, 1989, to David B. Chaney. .Iaddend.
SUMMARY OF THE INVENTION
This invention relates to a convertible fan assembly and more particularly to an electric fan assembly for household use that may be converted between use as in a window and use on a desk or floor.
Various convertible fan assemblies have been proposed or manufactured. These typically have a fan body and support members that are pivotally mounted relative to one another and to the fan body. However, the known convertible fan assemblies that have been proposed have a relatively complex construction and are therefore relatively costly to manufacture. Many would be difficult to convert from one use to another. Some employ relatively fragile parts and some involve the use of electric power cables that must be twisted, and thereby weakened, during use, or during conversion from use in a window to use on a desk or floor, or vice versa.
An object of this invention is to provide an improved convertible fan assembly that is rugged and inexpensive to manufacture and overcomes the disadvantages of prior convertible fan assemblies mentioned above.
In accordance with this invention, a fan assembly which may be readily converted between use as a window fan and use as a deck or floor fan comprises a substantially rectangular, one-piece, molded plastic, support member having a top edge, a bottom edge parallel to the top edge, and two mutually-spaced and mutually-parallel side edges. The support member comprises a first support panel, a second support panel, and a pair of living hinges connecting the first and second panels to one another along a pivot axis perpendicular to the top and bottom edges of the support member and parallel to and intermediate the side edges of the support member. The plastic of choice for manufacture of the support member is polypropylene because of its well-known advantage for use in forming parts having living hinges.
The first support panel is the larger of the two and has means mounting an electric fan theron, the fan comprising a venturi ring, an electric fan motor, a fan blade, an intake grill, and an exhaust grill. One of the above-mentioned living hinges extends from the fan to the upper edge of the support member and the other of the living hinges extends from fan to the lower edge of the support member.
Another object of this invention is to provide a convertible fan assembly that is small or compact for convenient use as a desk fan but may be adjustably extended, when used as a window fan, to cover various different windows having substantial differences in width. In this connection, it is an object of this invention to provide an improved extender assembly for use with window fans, and especially window fans which are convertible to desk or floor fans. To this end, the convertible fan assembly of this invention is provided with an extender assembly comprising a pair of primary extender plates which may be fully housed within, or covered by, the fan support panels and may be slidably extended outwardly of the sides of the support panels to cover parts of the width of the window in which the fan assembly is used that is not covered by the rest of the fan assembly. In order to be housed or covered by the support panels, the horizontal extent of the primary extender plates is limited by the dimensions of the support panels and by the venturi ring and grill mounting structure.
Further in accordance with this invention, the mutually confronting surfaces of the primary extender plates are cut away to avoid interference with the fan and its mounting means, but have upper and lower rails that extend respectively above and below the fan and its mounting means. In addition, secondary extender plates are provided for covering the cut-out portions of the primary extender plates which otherwise would be exposed to the sides of the support panels. Lost motion drive means in the form of interferring projecting surfaces on the primary and secondary extender plates are used appropriately to position the secondary extender plates as the primary plates are extended or retracted.
Other objects and advantages will become apparent from the drawings and the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of a convertible fan assembly made in accordance with this invention shown for use as a window fan.
FIG. 2 is perspective view of the convertible fan assembly of FIG. 1 shown for use as a floor fan.
FIG. 3 is an exploded, perspective view of the convertible fan assembly of FIG. 1.
FIG. 4 is a cross-sectional view of the convertible fan assembly taken on line 4--4 of FIG. 1.
FIG. 5 is a fragmentary, exploded, perspective view of a portion of the fan assembly of FIG. 1 showing an exhaust grill mounting arrangement.
FIG. 6 is a fragmentary elevational view of a portion of the fan assembly of FIG. 1 showing a latch arrangement.
FIG. 7 is a fragmentary cross-sectional view taken along line 7--7 of FIG. 6.
FIG. 8, on the third sheet of drawings, is a fragmentary elevational view of a portion of the fan assembly as viewed from the same direction as FIG. 3 and particularly illustrates parts of the extender assembly of this invention shown fully extended.
FIG. 9 is a fragmentary cross-sectional view taken on line 9--9 of FIG. 8.
FIG. 10 is a fragmentary cross-sectional view similar to FIG. 9, but showing parts of the extender assembly fully retracted.
FIG. 11, on the second sheet of drawings, is a fragmentary cross-sectional view taken on line 11--11 of FIG. 8.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 3, a convertible fan assembly of this invention, generally designated 10, comprises a one-piece, molded plastic, rectangular, fan support member, generally designated 12, having an upper edge 12A, a lower edge 12B parallel to the upper edge 12A, a right side (as viewed in FIG. 1) edge 12C, and a left side edge 12D parallel to the right side edge 12C. Support member 12 comprises a first, larger, thin-walled support panel 14 and a second, smaller, thin-walled support panel 16. Larger panel 14 is in the form of a plate having a front face 18 and mutually-confronting L-shaped flanges 20 (FIG. 3) along the upper and lower edges thereof.
Here it should be noted that positional terms such as front and rear, upper and lower, and right and left, are used herein for convenience in a relative sense and not in an absolute sense.
A fan, generally designated 19, is mounted on the larger panel 14. For this purpose, formed integrally with the larger panel 14 is a fan motor mounting ring 22 and a spider comprising plural spokes 24 extending radially inwardly from the fan mounting ring 22, and a motor housing 26 supported in the center of the fan mounting ring 22 by the spokes 24. The fan mounting ring 22 is surrounded by a rearwardly facing, substantially square, venturi ring mounting frame 28 formed by a pair of mutually closely-spaced ribs 30 and 32.
With reference to FIGS. 3 and 4, the motor housing 26 provides support for a fan drive motor assembly 40 that is adapted to drive a fan blade 42 and which is affixed to the motor housing 26 as by screws 44. A substantially square venturi ring assembly 46 is fixedly-mounted on the mounting frame 28 by plural screws 47, only one of which is shown in FIG. 3. The venturi ring assembly 46 includes a generally cylindrical outer wall 48 at the rear end of which is a venturi ring 49 surrounding the fan blade 42. An intake grill 56 which may be of conventional construction, is mounted in the venturi ring mounting assembly 46. Intake grill 56 may be formed by molding it in one piece with the venturi ring mounting assembly 46.
Referring to FIGS. 4 and 5, a circular exhaust grill assembly 50 is mounted for rotation on a forwardly-extending hollow stub axle 51 formed integrally with the motor housing 26. The exhaust grill assembly 50 has a centrally-located hub 52 provided with a diametrically-opposed pair of internal grooves 52A adapted to slide over lugs 51A extending outwardly from the stub axle 51. A retaining and clamping knob 53 provided with a spindle 53A having outwardly-extending lugs 53B cooperates with the stub axle 51 to retain the grill assembly hub 52 and, accordingly, the entire grill assembly 50 on the stub axle 51. For this purpose, the internal wall of the stub axle 51 is provided with camming grooves 51B, which snugly receive the knob lugs 53B. The camming grooves 51B extend axially and circumferentially along the inner wall of the stub axle 51. During assembly, the hub 52 is slipped over the stub axle 51. Thereafter, the knob spindle 53A is inserted into the stub axle 51 with the knob lugs 53B being located in the camming grooves 51B. The knob spindle 53A is partly surrounded by a circular flange 53C that faces the exhaust grill assembly 50 in order to retain the exhaust grill assembly 50 on the stub axle 51.
If desired, the knob 53 may be rotated as permitted by the camming grooves 51B to axially move the knob 53 into a position wherein the exhaust grill hub 52 is nonrotatably clamped between the knob flange 53C and the front face of the motor housing 26. The exhaust grill assembly 50 preferably has louvers 54 that are at an angle of approximately 15 degrees relative to horizontal so that the exhaust grill assembly 50 may be clamped by rotation of the knob 53 in a position wherein it directs air to a selected portion of the area in which the fan assembly 10 is being used. It should be understood that the rotatable mounting of the exhaust grill 50 is optional; a fixedly-mounted exhaust grill (not shown) could be used instead.
Referring again to FIGS. 1 and 3, the smaller support panel 16 is of a generally rectangular construction and has a front face 66 and upper and lower, mutually confronting, L-shaped flanges 68. A pair of living hinges 70 and 72 connect the upper and lower edge portions, respectively, of the panels 14 and 16 and the smaller panel 16 has a substantially C-shaped cut-out region 74 adapted to receive the confronting portion of the venturi ring mounting frame 28. As is well known, living hinges, such as 70 and 72, are formed by thin-walled sections of suitable material, preferably polypropylene. The living hinges 70 and 72 form a pivot axis "A" perpendicular to the upper and lower support member edges 12A and 12B are located centrally between and parallel to the support member side edges 12C and 12D. The hinges 70 and 72 extend from the respective upper and lower edges of the venturi ring mounting frame 28 to the respectively-adjacent upper and lower support member edges 12A and 12B. The upper and lower arms, designated 16A and 16B, respectively, of the smaller panel 16 that form the top and bottom portions, respectively, of the C-shaped cut-out region 74 extend to the living hinges 70 and 72 so that the panels 14 and 16 may be pivoted relative to one another about the pivot axis "A." More particularly, the top and bottom portions 16A, 16B of the panel 16 have upper and lower inner side edge portions 16C, 16D thereon which extend along the pivot axis A. Also, the panel 14 has upper and lower inner side edge portions 14A, 14B which extend along the pivot axis A and confront the upper and lower inner side edge portions 16C, 16D of the panel 16. Further, the panel 14 has a middle extension portion 14C located between its upper and lower inner side edge portions 14A, 14B and extending beyond the latter and beyond the pivot axis A past the upper and lower inner side edge portions 16C, 16D of the panel 16 and into its cutout region 74. The upper and lower living hinges 70, 72 respectively connect the upper and lower inner side edge portions 14A, 16C and 14B, 16D of the panels 14, 16, permitting pivotal movement of the extension portion 14C of the panel 14 relative to the cutout region 74 of the panel 16 as the panel 14 is pivoted relative to the panel 16 about the pivot axis A. As seen in FIG. 1, the fan 19 is stationarily mounted exclusively on the panel 14 and its extension portion 14C and thus will move with it relative to the panel 16. Thus, the panels 14 and 16 may selectively be oriented with their front faces 18 and 66 in a coplanar position as shown in FIG. 51, for use of the fan assembly 10 in a window, or oriented, as shown in FIG. 2, with the panels 14 and 16 at an acute included angle with respect to one another for use of the fan assembly 10 on a desk or floor, in which event the support member side edges 12C and 12D engage a support surface F. However, the fan 19 remains stationary with respect to the panel 14 and its extension portion 14C in both flat and folded orientations of the panels 14, 16.
With reference of FIG. 3, the panels 14 and 16 may be held in their mutually coplanar relationship for use of the fan assembly 10 in a window by a pair of manually-operable clips 60 mounted on the smaller panel 16. As shown in FIGS. 6 and 7, each clip 60 comprises a generally J-shaped body comprising a longer leg 60A and a shorter leg 60B with a bight 60C between the two legs. A flange 60D extends from the shorter leg 60B and is connected to the smaller panel 16 as by a screw 62. The flange 60D may have apertures for receiving locating pins 60E extending from the smaller panel 16 to better secure the clip 60. When the support panels 14 and 16 are maintained in coplanar relation, an elongate wedge 60F projecting from the longer clip leg 60A enters a notch 64 provided for this purpose between the venturi ring mounting frame 28 and the venturi ring mounting assembly 46. As is deemed apparent, the wedge 60F will be self-biased by the clip 60 to enter the notch 64 when the panels 14 and 16 are moved into a mutually coplanar orientation so that the panels 14 and 16 will be locked to one another. To convert for use as a floor fan, one may simply manually grip the longer clip arms 60A to remove the wedges 60F from the notches 64.
To retain the acute angular orientation of the panels 14 and 16 shown in FIG. 2, the L-shaped flanges 20 may be provided with integrally-formed spring hooks 80 adapted to enter cooperating slots 82 in the L-shaped flanges 68. Here it may be noted that the confronting end portions, designated 20A and 68A, respectively, of the L-shaped flanges 20 and 68 slope rearwardly and outwardly away from the living hinges 70 and 72 so that they will not interfere with the pivoting of the panels 14 and 16 to their angular orientation shown in FIG. 2.
Referring again to FIGS. 1, and 3, the fan assembly 10 further includes a pair of extenders 86 and 88, one for each of the longer panel 14 and the shorter panel 16, respectively. These extenders are used, as is well known in the art, to extend the effective width of the fan assembly 10, when used in a window, to ensure that the entire width of the window is covered. The extender 86 and the manner in which it is slidably mounted may be substantially identical to the extender 88 and its related mounting arrangement. Therefore, only the extender 88 and its mounting arrangement is illustrated and described in detail herein. With reference also to FIGS. 8 through 11, the extender 88 comprises a generally rectangular panel 90 formed with an upper ribbed rail 92, a lower ribbed rail 94, and a substantially C-shaped cut out 96 for the fan mounting parts, in particular the venturi ring mounting frame 28. The rails 92 and 94 are not cut-away so that their inner ends, when the extenders are fully retracted, straddle, and thereby accommodate, the venturi ring mounting frame 28.
Located within each of the L-shaped flanges 20 and 68 is an elongate divider strip 98. The extender rails 92 and 94 of the extender 88 are slidably mounted between the rear walls of the L-shaped flanges 68 and the associated divider strips 98. Each divider strip 98 has a cam-like stop member 100 that cooperates with a stop tab or flange 102 projecting forwardly from the inner side edge of the extender 88. The stop members 100 are effective to permit assembly of the extender 88, at which time each stop tab 102 cams over the more gradually sloping surface of its associated stop member 100, but are also effective to prevent excessive outward movement of the extender 88 and thereby prevent easy or accidental disassembly of the extender 88 from the panel 16.
In use, the extender 88 is effectively housed behind the panel 16 when the extender 88 is retracted. It may be manually extended when desired by simply pulling it sideways out of the panel 16. Such movement is resisted, and effectively detented, by the frictional interference between a plurality of projections 104 on the rear face of the extender rails 92 and 94 and plural vertical ribs 105 located on the inside face of the rear legs of the L-shaped flange 68.
The extenders 86 and 88 may be moved outwardly to such an extent that the extender cut-out portions 96 would be exposed past the side edges 12C and 12D of the support member 12. So that the fan assembly 10 may still be optimally usable, a pair of secondary extender plates 106 and 108, respectively, are slideably mounted within the area defined between the rear faces of the panels 14 and 16 and the divider strips 98. The secondary extender plates 106 and 108 are normally housed behind the panels 14 and 16, but have a lost-motion connection to the extenders 86 and 88 so that they are extended to cover the opening that otherwise may be formed by the extension of the cut-out portions 96 past the sides of the panel 14 and 16. As the extender 88 is moved sideways to extend it from the position shown in FIG. 10 to that shown in FIG. 9, the stop flange or tab 102 engages the inner side edge of the secondary extender plate 108, causing it also to be extended. If the extender 88 is moved to the fully extended position shown in FIG. 9, further outward travel of the secondary extender plate 108 is prevented by engagement of a pair of hook-like stops 110 thereon with a rib 112 on the rear face of the support panel 16. Ramp or cam surfaces 114 may be provided adjacent the parts of the rib 112 engaged by the hook-like stops 110 to permit the parts to be assembled by camming over one another. Upon retraction of the extender 88, the secondary extender plate 108 is caused to return to its retracted position by engagement of a flange 116 on the outermost side edge of the extender plate 88 with the outer side edge 118 of the secondary extender plate 108. As should be apparent, the secondary extender plate 106 is moved by the extender 86 in the same manner described above for the movement of the secondary extender plate 108 by the extender 88.
From an electrical standpoint, the operation of the fan assembly may be entirely conventional. It is provided with a control switch 120 having a switch operating shaft 122 extending forwardly and rearwardly with front and rear operating knobs 124 and 126, respectively, operable from either front or rear of the fan assembly 10. The motor lead wire may extend through a spoke, designated 24A, modified for this purpose. Because the parts of the fan assembly 10 through which the motor and external leads extend are non-rotatable with respect to one another, there is no concern with regard to possible twisting of these leads.
Although the presently preferred embodiment of this invention has been disclosed, it will be understood that various changes may be made within the scope of the appended claims.
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An electric fan assembly for household use convertible between use in a window and use on a desk or floor has a substantially rectangular, one-piece, molded polypropylene support member formed from a first support panel, a second support panel, and a pair of living hinges connecting the first and second panels to one another along a pivot axis perpendicular to the top and bottom edges of the support member. The first support panel is constructed to provide a mounting for an electric fan motor, a venturi ring assembly including an intake grill, and an exhaust grill. In use, the two support panels may lie flat for use in a window or may be pivoted about the axis of the living hinges for use on a deck or floor. Extenders are provided for extending the effective width of said fan assembly for use in relatively wide windows and includes secondary extender plates connected to the extenders by lost motion for increasing the length of extension obtainable. The exhaust grill is optionally mounted for rotation.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/332,723 filed Jun. 14, 1999, now U.S. Pat. No. 6,266,094 granted Jul. 24, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to methods and systems for monitoring, decoding, transmitting, and archiving of closed caption texts from television broadcasts. More particularly, the present invention relates to methods and systems for the automatic collection and conditioning of closed caption texts originating from multiple geographic locations, and resulting databases produced thereby.
[0004] 2. Description of the Prior Art
[0005] In the United States, television stations currently create more than 12,000 hours of local news programming every week. Network and cable news organizations broadcast an additional 1,400+ hours. Because every newscast contains references to specific persons, organizations, and events, an entire industry has grown up to monitor newscast content on behalf of newsmakers. The traditional monitoring approach required workers to videotape, view, and summarize the content of TV newscasts. However, using such a traditional method, it is very difficult to monitor every newscast on every channel on a timely basis. Thus, a need exists for newsmakers and other interested parties to have comprehensive and cost effective real time access to a database of newscast content.
[0006] Closed captioning, which is mandated by the Federal Government for most television programs, is a textual representation of the audio portion of a television program. Originally devised as a means for making program dialogue accessible to the deaf and hearing impaired, closed captioning is often displayed now for the convenience of non-deaf persons in environments where television audio is not practical, such as noisy restaurants and airport kiosks. Closed captioning is encoded into the video blanking intervals (VBI), which are part of the video component of a conventional television signal. In the United States, line 21 of the VBI is reserved for carrying closed captioning.
[0007] One approach to monitoring television broadcasts by using closed caption text is disclosed in U.S. Pat. No. 5,481,296, issued Jan. 2, 1996, to Cragun et al., and titled APPARATUS AND METHOD FOR SELECTIVELY VIEWING VIDEO INFORMATION. The Cragun et al. system provides a closed caption decoder that extracts the closed caption text from a television broadcast. A viewer specifies one or more keywords to be used as search parameters and a digital processor executing a control program scans the closed caption text for words or phrases matching the search parameters. The corresponding complete video recording of the television broadcast may then be displayed, edited, or saved. In one mode of operation, the Cragun et al. system may be used to scan one or more television channels unattended and save items that may be of interest to the viewer. In another mode of operation, the Cragun et al. system may be used to assist in quickly locating previously stored video recordings. One clear disadvantage of the Cragun et al. system is that extremely large amounts of memory are required to store the video segments.
[0008] One approach to monitoring television broadcasts by using closed caption text is disclosed in U.S. Pat. No. 5,809,471 issued Sep. 15,1998 to Brodsky et al and titled RETRIEVAL OF ADDITIONAL INFORMATION NOT FOUND IN INTERACTIVE TV OR TELEPHONY SIGNAL BY APPLICATION USING DYNAMICALLY EXTRACTED VOCABULARY. Significant limitations of the Brodsky patent are that server based features are missing and only single closed caption data is monitored from a specific geographic site, as opposed to broad geographical and dispersed sites in the present application. As such, the present design has features and benefits that are not in the Brodsky design.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a substantially real-time, comprehensive, and cost effective means for the monitoring, decoding, transmission, filing and retrieval of television word content through the client server based processing of closed caption text. It is another object of the invention to provide such means that makes such text accessible to end users via the Internet or other communication networks. It is another principal object of the present invention to provide automatic delivery of such search resultant text to non-current (i.e., prior inquiry) clients. It is a further object of the present invention to provide an automated, minimal cost, sales promotional tool to prospective customers using the method, system, and database of the present invention. Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.
[0010] The foregoing objects of the present invention are achieved by providing a system for the automatic collection and conditioning of closed caption texts originating from multiple geographic locations, comprising: (1) at least one remote capture client means having a tuner to receive one or more television signals, a decoder to decode closed caption text stream in the television signals, and means to write the closed caption text stream to a text file, (2) central server means operatively connected to the remote capture client means for storing the text files and making the text files available to a user, and (3) an inquiry client means operatively connected to the central server means for searching the text files. The central server is adapted to automatically process search requests from the inquiry client and notify the inquiry client via any suitable communications means, and particularly so when the inquiry client is not in active communication with the central server.
[0011] In one preferred embodiment, the non-current inquiry client would receive an electronic message (i.e., e-mail) containing the substantially real-time search resultant texts matched to a prior existing same client search inquiry profile.
BRIEF DESCRIPTION OF THE DRAWING
[0012] [0012]FIG. 1 is block diagram of a system for capturing, processing, and displaying closed caption text according to the present invention having a remote capture client, an inquiry client, and a central server;
[0013] [0013]FIG. 2 is a block diagram representing two methods of transferring text files from the remote capture client to the central server;
[0014] [0014]FIG. 3 is a block diagram representing the operation of the remote capture client of FIG. 1;
[0015] [0015]FIG. 4 is a block diagram representing the operation of the inquiry client of FIG. 1.
[0016] [0016]FIG. 5 is a block diagram representing the operation of the central server of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Referring to the drawings and, in particular, FIG. 1, there is illustrated a system according to the present invention having remote capture client means 100 , inquiry client means 110 , and a central server 130 .
[0018] Remote capture client means 100 generates decoded closed caption text files. Remote capture client means 100 may be operated as a client or as a server (see FIG. 3). Remote capture client means 100 sends a text file 140 to central server means 130 through communication means 120 using a client to server networking program 260 . Communication means 120 may be any suitable method of communication, including the internet, a local area network (LAN), and/or a wide area network (WAN). Client to server networking program 260 can manage numerous text files arriving from a plurality of remote capture client means.
[0019] Inquiry client means 110 is used to accesses central server means 130 for the purpose of searching closed caption text files stored on central server means 130 . Inquiries and results are transmitted between inquiry client means 110 and central server means 130 via communications means 120 . The connection between inquiry client means 110 and central server means 130 may be user-initiated or “interactive.” In the alternative, the connection may be automatically initiated by central server means 130 at a pre-selected time or when results from a pre-specified search are available.
[0020] Central server means 130 is connected to both remote capture client means 100 and inquiry client 110 . Central server means 130 collects, conditions, and stores text files received from remote capture client means 100 . In addition, central server means 130 receives inquiries from inquiry client 110 , processes those inquires, and returns search results to inquiry client 110 . Preferably, central server means 130 performs its tasks on a continuous basis, 24 hours a day, 7 days a week.
[0021] [0021]FIG. 2 illustrates that remote capture client means 100 may be connected directly and/or indirectly to central server means 130 . An indirect connection between remote capture client means 100 and central server means 130 passes through a remote capture server means 220 .
[0022] Remote capture client means 100 may be located geographically, strategically, economically, and/or conveniently. In many locations, remote capture client means 100 can satisfy all of the closed caption capturing requirements and, as such, a lower cost system may be employed wherein remote capture client means 100 communicates directly with central server means 130 through client to server networking 260 (see also FIG. 1). In the alternative, remote capture client 100 may be employed together with a supplemental capture client means 100 a . When supplemental capture client means 100 a is used in the system, remote capture client means 100 and supplemental capture client means 100 a are preferably connected to remote capture server 220 via a suitable communications means, such as the internet, a LAN, and/or a WAN. Remote capture client means 100 and supplemental capture client means 100 a send text files to remote capture server means 220 rather than directly to central server means 130 . Remote capture server means 220 collects text files from both remote capture client means 100 and supplemental capture client means 100 a . Remote capture server means 220 communicates to central server means 130 , as time, conditions, or other requirements are satisfied. For example, remote capture server means 220 may collect information from its assigned capture clients 100 , 100 a during a twenty-four hour period and transfer the collected text files to central server means 130 in a single communication session via server to server networking 240 . Moreover, remote capture client means 100 may be adapted to directly or indirectly communicate with supplemental capture client 100 a for centralization, redundancy, load sharing, and/or cost saving reasons.
[0023] In a preferred embodiment of the present invention, text files are transferred from remote capture client means 100 to central server means 130 across the internet using a protocol, such as File Transfer Protocol (FTP). An FTP connection may be controlled either by remote capture client means 100 or central server means 130 . When an FTP connection is controlled by remote capture client means 100 , the FTP connection is referred to as a “push” connection because the text files are transferred by an outgoing FTP connection. When an FTP connection is controlled by central server 130 , the FTP connection is referred to as a “pull” connection because the text files are accepted from an incoming FTP connection. However, some servers reject incoming FTP connections. For example, a firewall restricts the ability of a server to “pull” data. Nonetheless, all servers can “push” data. Thus, it is preferable that the system according to the present invention be designed to “push” rather than “pull” text files.
[0024] FTP sessions between remote capture client 110 and central server 130 may transfer entire directory structures. Optionally, the source text files may be deleted from local capture client 100 after the transfer is complete and the system has verified that the text files exists on central server 130 . This is a true “move” operation. Of course, if the text files are not successfully transferred, the system will re-transfer the sources files during the next FTP session. The system may establish an FTP session between remote capture client 100 and central server 130 automatically either (1) when a text file is created at remote capture client 100 , (2) a specific time interval has elapsed (e.g. 60 minutes), and/or (3) a specific time has been requested (e.g. 2 AM). A preferred FTP API is available in Microsoft's Windows 2000. Optional features may be implemented in the present system, method, and database using an API wrapper.
[0025] Remote capture client means processing is outlined by FIG. 3. Remote capture client means processing begins with one or more conventional signal sources 310 , which may be received by a broadcast antenna, broadcast cable, video tape player, or any other video source. Convention signal source 310 is received by to a tuner 320 . Tuner 320 is tuned to receive a desired frequency by hardware and software functions contained in a setup, scheduling, and programming means 360 via a graphical user interface 370 . Preferably, the setup, scheduling and programming means 360 manages tuner 320 , as well as a decoder 330 , and a text handler 340 .
[0026] Tuned signals are passed from tuner 320 to decoder 330 . Decoder 330 interprets and/or decodes any closed caption text in the tuned signals. A preferred embodiment of decoder 330 has been developed by Medialink Worldwide, Inc. and is known as TeleCap™. Other suitable decoding programs are commercially available and include, by way of example, Le Petit Decoder™ by SoftNi Corporation.
[0027] Decoder 330 passes the interpreted closed caption text to text handler 340 , which writes the closed caption text into a text file. Text handler 340 can insert useful information into the text file including broadcast related data, such as time, date, broadcast station identifiers, broadcast market identifiers, broadcast station city, program title, and program actors and/or participants.
[0028] Text output process 350 sends the text file from text handler 340 either to central server means 130 or a remote capture server means 220 (see FIG. 2). Preferably, text output process 350 is initiated after a text file is closed. Closing a particular text file can be accomplished under user specified control or based upon system pre-set parameters governed by the application. For example file closing may occur automatically when the recorded program concludes, a specific time interval has elapsed (e.g. 60 minutes), or a specific time has been requested (e.g. 2 AM), as well as other opportunities as warranted.
[0029] Tuner 320 , decoder 330 , text handler 340 , setup, scheduling, and programming means 360 , and graphical user interface 370 may be incorporated into a single hardware device. A number of commercially available computer hardware devices and internal computer boards provide tuning and decoding capabilities. For example, a preferred embodiment of the present invention makes use of a computer board manufactured by the PosTech Company of Madison, Wis. However, any closed captioning decoding device known in the art may be used as part of the present invention.
[0030] Preferably, both remote capture client means 100 and central server means 130 can manage aspects of remote capture client means processing and operation, such as 1) initialization, 2) programming, 3) upload and download times, 4) error processing and 5) updating.
[0031] [0031]FIG. 4 outlines inquiry client means processing. A user employs a graphical user interface 410 to define a text inquiry definition 420 . Text inquiry definition 420 is structured by a send command and control program 430 for submission to central server means 130 via an inquiry output program 440 . Text inquiry definition 420 can be maintained on inquiry client 110 by an inquiry filing and management program 490 . This allows the user to review previous postings and to use the same inquiry or a modified inquiry in the next search interval.
[0032] Text inquiry definition 420 may also be maintained as part of a detailed search profile. Such a search profile will include information about the text inquiry definition, such as key words, key phrases, selected stations, selected markets, when and/or if the text inquiry definition should be compared against the database of text files (e.g., every 24 hours for 30 days), and limits to the search results (e.g., the first 100 records found). A search profile will also include information about the user that submitted text inquiry definition 420 , such as name, password, email address, and limitations on access (e.g., 5 text inquiry definitions per month).
[0033] In preferred embodiments, users have the option to permanently save one or more profiles for later retrieval and use during an active user-initiated search or alternatively, in an automatic current user interactive search. Moreover, users have the option to share permanently saved profiles with other selected users. In addition, profiles must necessarily be permanently saved for some discrete time frame on central server means 130 as part of automated search routines, such as automatic search processing 580 (see FIG. 5). The search profiles can be saved at central server means 130 and/or inquiry client means 110 . To conserve resources, if a given profile is not permanently saved, central server means 130 maintains the profile for a pre-determined interval (e.g., one day) and then removes the profile. Preferably, removing profiles from central server means 130 is done when system demand is low. A preferred routine for removing profiles from central server means 130 uses a scheduled command, such as Microsoft SQL Server Agent, which is available as part of Microsoft SQL Server 6.5 and in newer versions.
[0034] A return posting 460 from central server means 130 is processed by the receive command and control routine 470 to manage any interface exchange or conversion option required by the application. Return posting 460 may be in one or more forms, such as an interactive results return or an automatic notification. Search results returned to inquiry client 110 will be displayed at graphical user interface 490 as formatted by reporting options routine 480 . For example, the search results can be displayed as a list of program citations, with each citation having a sub-listing of key sentences. In addition, graphical user interface 490 can display Internet-oriented pages, links, and/or buttons. Buttons on the results page allow a user to expand key sentences into stories and stories into whole newscasts. Program citations identify specific news programs that include the words being searched for. For example, a program can be identified by the date it was broadcast, the city (or market) from which the broadcast originated, the call letters or name of the station or program source originating the broadcast, the name or title of the program, and the time of day the program was broadcast.
[0035] In a preferred form of the present invention, inquiry client 110 sends and receives search results and/or text files from central server 130 via a web browser. Numerous methods have been developed to provide information over the web in a user-friendly format. Moreover, improvements to existing technology are being developed at a very rapid pace. The system, method, and database of the present invention may be adapted to utilize any current or future technology for web-based data transfer. For example, server-side scripting is a popular and effective environment for presenting data from a server to a user. Currently, the system, method, and database of the present invention may utilize server-side scripting in the form of one or more environments, such as ASP, ISAPI, VB.NET, ASP.NET.
[0036] Referring to FIG. 5, central server means processing begins with the receipt of a text file 140 from remote capture client means 100 . Text file 140 can be processed by a series of subroutines designed to enhance the integrity and uniformity of text files, as well as archive, index, search, and deliver text files.
[0037] Text file 140 may be processed by a conditioning routine 510 that is designed to impose format consistency across all text files received by central server means 130 regardless of their origin. Text files from different networks, geographic areas, and locales may use nonconforming close captioning standards since several format standards are available for use. The recommended formatting standard is the standard established by the National Captioning Institute (NCI). NCI standards, amoung other things, specify specific symbolic patterns to mark the beginning or end of a single news story within a news broadcast. However, many broadcasters do not follow NCI standards. Nonetheless, broadcasting stations sometimes specify which standards they actually follow. Some broadcasting stations do not specify what standards they follow, but patterns can often be detected, either by a human or by computer, that indicate specific symbols the broadcasting station may be using in place of the NCI standards. As such, conditioning routine 510 can apply the particular standards or patterns of a given broadcast station to text files captured from that broadcast station, so that the resulting output text more closely follows a single standard. Thus, the conditioning routine 510 allows text files that deviate from NCI standards to be converted to substantially conform to NCI standards. Converting non-conforming text is preferably accomplished by comparing each and every text file received by central server means 130 against a database of station-specific formatting standards. Conversion routines developed for specific stations are invoked to change a nonconforming format to NCI standard formatting. For the present invention, the preferred program for performing the comparison and conversion of text files has been developed by Medialink Worldwide, Inc. and is referred to herein as ccScrub™, which is indicated in FIG. 4 as reference numeral 511 .
[0038] A spelling check 512 may be used as part of conditioning routine 510 to impose spelling and abbreviation consistency to all sources. For example, the company name “AT&T” is spelled many different ways by different broadcasters (e.g., “A-T-and-T,” “A T & T,” and “A T and T”). An abbreviation subroutine in spelling check 412 would search for predefined variations of a company name and convert all variations into the standard abbreviation.
[0039] Text file 140 may be processed by a parsing routine 420 . Parsing routine 420 is designed to parse an entire newscast or television event into its unique story parts or segments. Parsing routine 420 can apply user-defined and/or default rules to determine the parsing points within a program. Preferably, parsing routine 420 first determines whether a text file contains useful data. If a broadcaster has failed to provide captions for a given newscast or broadcast, the resulting text file will only contain time stamps. By counting the number of letter characters and the number of numeral characters in the file, a ratio can be calculated that may then be used to determine if a text file is worth processing. For example, if the letter to number ratio is below a user-defined variable, the file can be rejected for further parsing. If a text file is accepted for further parsing, markers are created within the text file for denoting the beginning and end of segments within text file 140 . For example, a user-defined rule can set the end of a segment whenever a user-defined variable of time has elapsed without attendant captioning. A default rule could search for occurrences of the “>>>” symbol, which is the NCI standard symbol for denoting the beginning of a new story within a broadcast. Another default rule could search for occurrences of multiple time stamps uninterrupted by text and mark the beginning and ending of such sequences. A certain number of uninterrupted time stamps may denote either the occurrence of a commercial break or other non-captioned segment of a newscast. Once the appropriate markers have been inserted in text file 140 , the content between each marker can be written to a new, separate text file. Each parsed text file preferably includes program origination information, total running time, and other segment information to better identify unique segments within a program. The new text files are named (e.g., by sequential number) and saved (e.g., to a new directory named for the particular newscast being processed). Parsing routine 420 continues until all identifiable segments of text file 140 have been written to separate parsed text files. When all the separate parsed text files have been written, the original text file 140 is preferably deleted from the disk. A preferred program for parsing text files has been developed by Medialink Worldwide, Inc. and is referred as ccSplit™.
[0040] Indexing routine 430 creates an index of the words contained in text file 140 . The words in text file 140 are preferably indexed along with other information about text file 140 , such as its time and place or origin. The preferred program for use in indexing routine 430 is the Microsoft™ Index Server (version 2.0) or the Microsoft™ Content Indexing Services (version 3.0). However, any appropriate indexing software may be used.
[0041] Another element of indexing routine 430 is a search engine interface 431 that allows users to submit search profiles, as described above, to the index of words. Search engine interface 431 could allow searches using Boolean logic. The results data generated by searching the index of words against a submitted profile are written to a results database 460 . Writing search results to results database 460 allows for the ordering and other manipulation of the results data. The preferred results database is a structured query language database, such as Microsoft™ SQL Server, although other databases may be used.
[0042] Managing routine 470 supports the need for file management, archiving, restoring, and backing-up, as well as satisfying the overall file integrity requirements of central server means 130 . Preferably, an appropriate graphical user interface (not shown) is employed for these purposes. System information, including text information, system operational parameters, and query postings can be appropriately managed, archived and compressed as needed for system calibration, redundancy and report management purposes.
[0043] One particularly preferred embodiment includes automatic search processing routine 480 . A web page interface from inquiry client means 110 , for example, allows a user to initiate automatic search processing routine 480 . Automatic search processing routine 480 submits a search profile to the index of words, either at a pre-determined time, or time interval, or each time the index of words is updated. The results are written to database 460 in the same fashion as described above. If and when results are written to results database 460 , the user is notified via a messaging system and/or device, such as an electronic mail message (“e-mail”) or a mobile telephone. Notification may be initiated by central server means 130 in the form of an electronic mail message, a “pop-up window,” and/or other suitable forms. In the alternative, notification may be initiated when inquiry client means 110 establishes communications with central server means 130 , such as by a dial-up connection. The preferred embodiment of automatic search processing routine 480 is a program developed by Medialink Worldwide, Inc. called AutoAlert™.
[0044] Optionally, central server means processing may include a document generating routine 570 for generating documents in printer-friendly format rather than merely for display on a monitor. Selected text documents that are sent to inquiry client 110 by central server means 130 to inquiry client means 110 are preferably formatted for an Internet-oriented graphical user interface (i.e., a web browser). A particularly preferred format is hypertext markup language (HTML). Yet, there are cases where a user may want to have selected text documents formatted specifically for printing. While it is often possible for a user to print a document initially formatted in HTML, the formatting of such a printed document is often undesirable. For example, there is no way to specify a section or sub-section header or footer or a specific location to start a new printed page in HTML, so a text file that spans more than one printed page would only have a citation at the beginning of the printed document.
[0045] Instead of HTML formatting, a user may elect to have a selected text document formatted directly into a printable and reader-friendly format, such as a Microsoft Word™ document, and downloaded to inquiry client means 110 . Such a printable and reader-friendly document may contain useful information not included in an HTML formatted document. For example, each page of such a printable and reader-friendly document may have a page number, section headers, the search parameters used to find the document, and/or the time, day, and program from which the text in the documents was captured. Furthermore, each printable and reader-friendly document can be selectively limited in size (e.g., 250 Kbytes). Preferably, the useful information added to documents for a particular user can be pre-defined by the user and saved in a user-profile, as discussed above.
[0046] Directly formatting text files into a printable and reader-friendly document is particularly useful and mutually enhances other sub-processes of the present system, such as AutoAlert™, since the printable and reader-friendly document can be automatically e-mailed to a user. For example, a user may create and save a search profile on central server means 130 , as described above. Using routines as described above in reference to central server system processing, a printable and reader-friendly document can be automatically generated and sent to the user with or without an accompanying report and/or summary. Preferably, the printable and reader-friendly document is automatically sent to the user utilizing server-side scripting, such as Microsoft's™ VB Script™, and/or mail protocols, such as SMTP. This automated search and delivery routine may be scheduled to occur at intervals pre-determined either by the user or center server means 130 . One predetermined event to trigger automated search and delivery routine 480 is when there is a broadcast event containing content that matches a prior search profile from inquiry client 110 . A reader-friendly, printable document containing the search results and/or document is automatically e-mailed to inquiry client 110 . A preferred means for scheduling a search and delivery routine is Microsoft Windows 2000 Task Scheduler, which is an included component of the Microsoft Windows 2000 operating system. In addition, to conserve resources on central server means 130 , a supplemental central server means (not shown) may be dedicated to the automated search and delivery process.
[0047] Central server means 130 may provide several methods for reviewing text files. The system optionally provides for retrieval of the complete file from which a key sentence is drawn, thus allowing the user to read in context the full text surrounding any found search term. Another system option provides a means for the user to compile only selected sentences and their citations to a report suitable for printing or otherwise preserving to a user's preferred format. Yet another system option provides a means for the user to compile selected full text versions of found search terms to a report suitable for printing or otherwise preserving to a user's preferred format.
[0048] Preferably, results from database 460 are displayed as a citation with associated phrases and/or short sentences that contain the keywords in the search profile. In other words, rather than returning the full text of entire broadcasts that contain the keywords, results can be initially returned as key sentences only. These key sentences, because they contain the keyword or words the user is looking for, provide an overview of the full text, allowing the user to quickly scan many broadcasts without having to look at the full text of each broadcast. The full text of any broadcast or portion thereof is available to the user, for example, by clicking on an associated button and/or link. Thus, users may first see their keywords within the context of specific sentences with the option of “zooming out” to see the sentences in the context of a story, and the story in the context of an entire broadcast. This hierarchy (citation→sentence→story→newscast) is an efficient way of displaying the results of a search that may return hundreds of found text files.
[0049] Results from database 460 may be displayed to a user as keywords or a short summary that is linked to the full text file stored on central server means 130 . Preferably, the link would contain embedded information that could be used by central server means 130 for management tasks, such as authentication, security, and/or user subscription. For example, ongoing automatic searches may be initiated using search inquires from keywords of interest to a selected business and/or interest group. Search results could be written to a database as described above followed by a targeted electronic mail message that is tailored for and addressed to the selected business and/or interest group. The targeted electronic mail message would contain a phrase or sentence from the search results linked to the full text file. By following the link, a user would access central server means 130 and view the full text file. Regarding user subscription, the foregoing automatic search and targeted messaging routine would be particularly useful in offering trial access to potential customers and/or users for searching limited by time and/or subject matter. A trial access satisfied potential customer could then become an ongoing subscriber by return e-mail or a web-based subscription.
[0050] The systems, methods, and databases of the present invention are broadly applicable. By way of example, a company that manufactures products may wish to know whether broadcast programs are discussing the company and/or its products, and whether such discussions are favorable and/or unfavorable. There is a real-time need for such information. The present invention permits a company to automatically access such information or to have such information automatically electronically transmitted to the company (e.g., via e-mail) for study or appropriate action. Likewise, a company may be able to automatically search and/or monitor authorized and unauthorized uses of its trademarks and trade names in broadcast programs and commercials, such as in tracking its own commercials and commercials by competitors, and to automatically receive related search results and reports.
[0051] Another commercial aspect of the present invention is an improved mechanism for attracting prospective customers or users of the present invention. A search profile tailored to a prospective customer and/or similarly interested prospective customers may be formulated and entered into the system in a manner as previously described. The system will automatically and periodically contact (e.g., via e-mail) the prospective customer(s), and automatically provide search results in one or more formats (e.g., a summary report) for examination by the prospective customer(s). The prospective customer(s) may then subscribe via the Internet, e-mail, or otherwise. In this manner, the system, method, and database of the present invention provide a powerful sales promotional tool at minimal costs and with effectively no sales personnel.
[0052] In the embodiments of the present invention described above, it will be recognized that individual elements and/or features thereof are not necessarily limited to a particular embodiment but, where applicable, are interchangeable and can be used in any selected embodiment even though such may not be specifically shown. It will thus be seen that the objects set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention that, as a matter of language, might be said to fall there between.
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There is provided a system for the automatic collection and conditioning of closed caption texts originating from multiple geographic locations, comprising: (1) at least one remote capture client means having a tuner to receive one or more television signals, a decoder to decode closed caption text stream in the television signals, and means to write the closed caption text stream to a text file, (2) central server means operatively connected to the remote capture client means for storing the text files and making the text files available to a user, and (3) an inquiry client means operatively connected to the central server means for searching the text files. The central server is adapted to automatically process search requests from the inquiry client and notify the inquiry client via any suitable communications means, even when the inquiry client is not in active communication with the central server.
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BACKGROUND
The present disclosure relates generally to semiconductor devices, and more particularly to a method for using retrograde well for forming Metal-Oxide-Semiconductor (MOS) transistors.
Typically, integrated circuits (ICs) operate at various operating voltages. Therefore, transistors in these ICs must withstand certain voltage thresholds. For example, transistors with gate lengths of less than 0.25 um typically must operate at less than 2.5 volts, while transistors with a longer gate length (>0.3 um) may operate at well over 3 volts. In certain high voltage applications such as power supplies and hard-disk controllers, even higher operating voltages may be required.
One undesirable effect when applying a high operating voltage to a MOS transistor not designed for such a high voltage is the accumulation of hot electrons at and around the junction of the channel and drain of the transistor. In turn, ionized electrons resulting from the hot electrons move to the drain, thereby causing the drain current to increase. When hot electrons increase to a point where the source/drain junction voltage exceeds a certain level, the source/drain junction of the transistor breaks down, thereby causing damage to the transistor. That certain level of source/drain junction voltage is also known as the breakdown voltage, and must be increased in high voltage environments wherein a high operating voltage is applied to the transistors.
In order to provide a higher breakdown voltage, a double diffused drain (DDD) is typically provided in many MOS transistors that need to operate in the high voltage environment. DDDs help to suppress the hot electron effect, thereby reducing electrical breakdown of the source/drain under high operating voltage.
However, high voltage MOS transistors with DDD are typically formed on a semiconductor wafer that also includes low voltage MOS transistors without DDD. Because the thermal budgets of the processes needed for the formation of high voltage MOS transistors are different from that of low voltage MOS transistors, it is difficult to integrate the manufacturing processes of high voltage MOS transistors to those of low voltage MOS transistors without materially causing permanent change to the physical characteristics of these transistors. As an example, since the drain of a high voltage MOS transistor needs to withstand high breakdown voltages, DDD is formed with a process whereby high temperature and long processing time are required. However, the high temperature and long processing time may drive ions in the doped regions of the low voltage MOS transistors into the silicon substrate beyond a predetermined depth, thereby causing the physical characteristics of the low voltage MOS transistors to become uncontrollable. As such, traditional processing methods are not practical in producing advanced semiconductor technologies that have both high voltage and low voltage MOS transistors because of the increasing uncontrollability.
One solution is to use a drain extended transistor, wherein a very lightly doped extension region adjacent to the drain is used. This extension not only allows voltage to be dropped across the extension region, but also reduces the electric field across any part of the gate oxide, thereby preventing breakdown. However, such extensions consume much wafer space, and are known to be very expensive in advanced technologies where transistor densities are high and wafer real estate commands a significant premium.
Desirable in the art of are additional designs that provide improved high voltage designs for advanced semiconductor technologies that may achieve a high breakdown voltage in the smallest-possible surface area.
SUMMARY
In view of the foregoing, the following provides a method that provides an improved high voltage design for advanced semiconductor technologies that may achieve a high breakdown voltage in a relatively small surface area.
In one embodiment, a high voltage device with retrograde well is disclosed. The device comprises a substrate, a gate region formed on the substrate, and a retrograde well placed in the substrate next to the gate region, wherein the retrograde well reduces a dopant concentration on the surface of the substrate, thereby minimizing damages to the gate region.
Such a high voltage device enjoys various advantages including space saving and the increase of voltage tolerance.
The construction and method of operation of the invention, however, together with additional objects 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 illustrates an NMOSFET with a retrograde well in accordance with one embodiment of the present disclosure.
FIG. 2 illustrates a PMOSFET with a retrograde well in accordance with one embodiment of the present disclosure.
FIG. 3 illustrates concentration profiles in accordance with one embodiment of the present disclosure.
FIG. 4 illustrates a damage-susceptible site in a MOSFET in accordance with one embodiment of the present invention.
DESCRIPTION
The present disclosure will provide a detailed description of a high voltage MOS Field-Effect-Transistor (MOSFET) structure that saves space and allows the traditional low-doped drain masks used for both N-type and P-type to be omitted.
FIG. 1 illustrates an N-channel MOSFET (NMOSFET) 100 constructed with structures that achieve high voltage performance in a high voltage range such as from 6 to 35 volts. A P-type deep well 102 , of appropriate doping and predetermined depth (usually a relatively deep doping profile) for high voltage devices, is formed within the bulk semiconductor substrate. Adjacent N-type wells 104 are also formed. The NMOSFET is electrically isolated at the surface of the substrate, from other devices, by isolation structures such as a shallow-trench-isolation (STI) or local-oxidation-of-silicon (LOCOS) 106 . A thin gate oxide 108 is formed on the surface of the semiconductor substrate and is covered by gate electrode material, typically, poly crystalline silicon 110 . Through normal MOS processing, sidewall spacers 112 are formed on the sidewall surfaces of the poly. An oxide layer 114 , which may also be STI or LOCOS, or may be thinner, is formed between and separated from the gate sidewall spacer structure 112 and the isolating STI/LOCOS 106 . This oxide 114 separates an N+ source region 116 , to be formed next to the sidewall spacer of the gate electrode, from a P+ contact 118 to the P-well 102 , to be formed next to the STI/LOCOS 106 . The P-well 102 may be a well that is suitable for high voltage devices and may be referred to as a high voltage well.
On the other side of the gate oxide structure 108 , a low voltage N-well (LVNW) 120 , shallower than the P-type well 102 , is formed within the P-well 102 . This LVNW 120 fills the space between the gate sidewall spacer structure 112 and the STI/LOCOS 106 . The LVNW 120 is formed by the implantation of an N-type dopant deeply below the surface. Now, when exposed to high temperature, the N-type dopant diffuses both further downward and also upward toward the surface. Because, unlike traditional diffused substrate, the concentration of the dopant is greatest at the implanted depth and is reduced toward the surface, this arrangement is called a retrograde well. The dopant concentration profile is reversed from that of the traditional arrangement in which the dopant is implanted at a very shallow depth adjacent to the surface and diffused downward. The traditional arrangement produces a highest dopant concentration at the surface and the concentration diminishes downward into the substrate. Here, an N+ doped region 122 is implanted into the middle region of the LVNW 120 and it is separated from the gate sidewall spacer structure 112 and the STI/LOCOS 106 . It is understood that the entire LVNW 120 along with the doped region 122 may be referred to as the drain region.
In the traditional arrangement, an N+ doped region is placed immediately adjacently to the sidewall spacer 112 of the gate poly 110 . In addition, an N− region, that is, a low-concentration N-type region, is placed in the substrate. This N− region is adjacent to the N+ doped region, and extends to the space under the sidewall spacer, which is adjacent to the gate poly. This is called a low-doped drain (LDD). The LDD here surrounds and isolates the doped region and therefore like an extension of the doped region 122 . It is thus referred to as a drain extension (hereinafter DE). The LVNW replaces the LDD of the traditional arrangement and becomes an alternative of DE. The extended space of the DE 120 here is occupied by the reduced N-type dopant that have diffused upward from the implanted depth in the LVNW 120 . In operation, the junction between the N-type drain, now surrounded by the LVNW 120 , and the P-type well 102 , is reverse biased.
It is further understood that although the LVNW 120 is a continuous piece as shown in FIG. 1 , it does not have to be so. The LVNW 120 can be two or more discrete or unconnected retrograde wells formed, usually in an aligned manner, to be placed in the area between the STI/LOCOS 106 and the gate. As such, in some embodiments, the doped region 122 may not be entirely within a retrograde well. That is, at least a portion of the dope region 122 may be overlapping or formed within the retrograde well, while some other portions of the doped region may be formed directly within the deep well 102 without the retrograde well 120 situated therebetween.
In the traditional LDD arrangement, the depletion region of the reverse biased junction extends both into the LDD and under the gate poly. In a high voltage application, this places a considerable field gradient of the reverse-biased junction under the edge of the gate poly with the gate oxide in between. The field strength may be enough to damage the gate oxide directly. Additionally, hot electrons are produced and some of them may be injected into the thin gate oxide, thereby potentially causing damage to the oxide. Also, the electron charges trapped in the oxide act as charges in a capacitor causing leakage in the adjacent junction.
In addition, only the retrograde well 120 extends under the edge of the gate oxide 108 . The retrograde well 120 has a lower dopant concentration near and all across the substrate surface between the N+ doped region 122 and the surface under the gate poly 110 . The reduced dopant concentration causes the electric field gradient of the junction to be spread over a greater distance and therefore to be lower. A lower field gradient adjacent to the thin gate oxide 108 is far less likely to cause damage to the gate oxide 108 or to inject hot electrons into it.
Furthermore, there may also be an isolation area inserted (not shown), in the retrograde well area 120 , between gate region 108 and doped region 122 . This isolation area may further increase the breakdown voltage threshold between the gate region 108 and doped region 122 . The increased breakdown voltage threshold would further lower the possibility of causing undesired damage to the gate region 108 or to inject hot electrons into it.
In short, the traditional LDD structure has been replaced by the retrograde LVNW 120 structure. This, in combination with the N+ doped region 122 , is a double diffused drain (DDD). This allows operation at higher voltages. The retrograde LVNW 120 is the same N-type well used for all of the low voltage P-channel MOSFET (PMOSFET) circuitry produced on the same substrate, thereby eliminating the need to use extra masks in the manufacturing processes. In the low voltage circuitry, the traditional LDD structure can be replaced by this same retrograde LVNW 120 structure safely.
FIG. 2 illustrates a P-channel MOSFET (PMOSFET) 200 constructed with structures that achieve high voltage performance in a wide voltage range such as from 6 to 35 volts. An N-type well 202 , of appropriate doping and deeper depth for high voltage devices, is formed within the bulk semiconductor substrate. Adjacent P-type wells 204 are also formed. The PMOSFET is electrically isolated at the surface of the substrate, from other devices, by either shallow-trench-isolation (STI) or local-oxidation-of-silicon (LOCOS) 206 . A thin gate oxide 208 is formed on the surface of the semiconductor substrate and it is covered by gate electrode material, typically, poly crystalline silicon (poly) 210 . Through normal MOS processing, sidewall spacers 212 are formed on the sidewall surfaces of the poly. An oxide layer 214 , that may also be STI or LOCOS, or may be thinner, is formed between and separated from the gate sidewall spacer structure 212 and the isolating STI/LOCOS 206 . This oxide 214 separates a P+ source region 216 , to be formed next to the sidewall spacer of the gate electrode, from an N+ contact 218 .
On the other side of the gate oxide structure 208 , a low voltage P-well (LVPW) 220 , shallower than N-type well 202 , is formed within the N-well 202 . This LVPW 220 fills the space between the gate sidewall spacer structure 212 and the STI/LOCOS 206 . The LVPW 220 is formed by the implantation of a P-type dopant deeply below the surface. Now, when exposed to high temperature, the P-type dopant diffuses both further downward and also upward toward the surface. Because the concentration of the dopant is greatest at the implanted depth and is reduced toward the surface, this is also a retrograde well. The dopant concentration profile is reversed from that of the traditional arrangement in which the dopant is implanted at a very shallow depth adjacent to the surface and diffused downward. The traditional arrangement produces a highest dopant concentration at the surface and the concentration diminishes downward into the substrate. Here, a P+ doped region 222 is implanted into the middle region of the LVPW 220 and it is separated from the gate sidewall spacer structure 212 and the STI/LOCOS 206 . In the traditional arrangement, a P+ doped region is placed adjacently to the sidewall spacer 112 of the gate poly 210 . Also, in the traditional arrangement, a P− region, that is, a low-concentration P-type region, is placed in the substrate, from the P+ contact, and under the space to be filled by the sidewall spacer, adjacent to the gate poly, which is referred to as a low-doped drain (LDD). Like the LVNW of the N type devices, the LVPW 220 is referred to as a drain extension (DE), and replaces the function of the LDD of the traditional arrangement.
In operation, the junction between the P-type drain, now formed by the LVPW 220 , and the N-type well 202 , is also reverse biased. Like the N-type structure described above, only the retrograde well 220 extends under the edge of the gate oxide 208 . The retrograde well 220 has a lower dopant concentration all across the substrate surface between the P+ doped region 222 and the surface under the gate poly 210 . The reduced dopant concentration causes the electric field gradient of the junction to be spread over a greater distance and therefore to be lower. Such a lower field gradient adjacent to the thin gate oxide 208 is unlikely to cause damage to the oxide 208 or to inject or remove hot carriers.
FIG. 3 illustrates the dopant concentration profiles 300 of the retrograde LVNW or LVPW and the traditional diffused N-well or P-well as low-doped drain extension. The traditional diffused profile shows the greatest dopant concentration at the substrate surface because the dopant is implanted at a very shallow depth adjacent to the surface and is then diffused downward only. The portion of the depletion region of a junction in the high dopant surface concentration at the substrate surface will be narrower and therefore, the electric field gradient will be steeper. Current carriers traversing the steeper gradient will be accelerated to higher energies which may cause direct damage to the gate oxide or may cause carriers to be injected into or removed from the thin gate oxide, which degrades MOS performance. In contrast, the retrograde dopant concentration profile shows the greatest dopant concentration at the implanted depth, from which the dopant is diffused both downward and upward toward the surface. The portion of the depletion region of a junction in the lower dopant concentration at the substrate surface, with a LVNW or LVPW, will be broader. Therefore, the electric field gradient will be gentler. Carriers traversing the gentler gradient will not be accelerated to damaging energy levels.
FIG. 4 illustrates the location in a MOSFET 400 that is susceptible to damage if current carriers are accelerated to excessively high energy levels by an electric field gradient that is too steep. The electric field of concern appears in the substrate 402 between the high dopant concentration in the doped region 406 and the drain extension end 408 , under the edge of the gate poly 410 with the thin gate oxide 412 in between. The gate oxide end 414 is most susceptible to damage. With the presently disclosed method for using the retrograde LVNW (or LVPW) drain extension 408 , the high energy stress is much less likely to be formed.
The high voltage device illustrated above enjoys various advantages including space saving and increase of voltage tolerance. In addition, the retrograde well increases surface breakdown threshold voltage, which is important for the operation of any high voltage devices. Since high and low voltage transistors are most likely in co-existence on a chip, having the high voltage devices made by using retrograde wells, at least two mask layers can be saved from the manufacturing process since the high and low voltage devices can be formed without requiring additional masks for high voltage devices. Further, the drain to gate distance is also reduced because of the drain extension. In some situations, when the high voltage well doping profile can be coordinated with the formation of the retrograde well, surface electrical fields can be reduced.
The above disclosure provides many different embodiments or examples for implementing different features of the disclosure. Specific examples of components and processes are described to help clarify the disclosure. These are, of course, merely examples and are not intended to limit the disclosure from that described in the claims.
Although the invention is illustrated and described herein as embodied in detailed 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 disclosure, as set forth in the following claims.
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A high voltage device with retrograde well is disclosed. The device comprises a substrate, a gate region formed on the substrate, and a retrograde well placed in the substrate next to the gate region, wherein the retrograde well reduces a dopant concentration on the surface of the substrate, thereby minimizing damages to the gate region.
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BRIEF SUMMARY OF THE INVENTION
This apparatus comprises a portable means of flushing marine engines. Until now marine engines have depended on pump pressured water to supply the engine's water pump during operation unless the lower unit was submerged. This system delivers water by means of gravity and a temporary storage reservoir which makes it portable.
BRIEF DESCRIPTION OF THE VIEW OF THE DRAWING
There is one view of the portable flush system. This is a side view which illustrates the reservoir and the water delivery system.
DETAILED DESCRIPTION
A. Production
A five gallon reservoir 1 with handle 2 is obtained. A hole 3 is drilled in the side of the five gallon reservoir 1 1"0 in diameter with the center approximately 1-1/4" above the bottom of the reservoir 1. A 3/4 male adaptor 4 is inserted through the reservoir 1 and tightened to the wall of the reservoir 1 with a 3/4" locknut 5. Silicone glue is used to prevent leakage. Teflon tape is applied to the outside threads of the adaptor 4 on the outside of the reservoir 1. A shut-off valve 6 is threaded onto the adaptor 4 and tightened. A 5' to 8' long 5/8" garden hose 7 is included that can be threaded onto the shut-off valve 6. This transports water from the reservoir 1 to a commercially produced motor flush unit that attaches to the water intake at the lower unit of the marine engine. A lid 8 is placed on the five gallon reservoir 1 during transportation when filled with water.
B. Operation
As stated earlier, this unit is portable due to the fact that gravity is the power source. It does not rely on electricity or external sources of water pressure to operate. It relies on gravity flow to force the water into the impeller of the water pump of the marine engine. Also, water is transported in the reservoir to the location of the engine. Initially, the shut-off valve is closed and the reservoir is filled with fresh water. The lid is then put snugly on the reservoir and the reservoir is transported to the location of the marine engine. The reservoir is then placed on a flat surface substantially higher than the water pump of the engine. One end of the 5/8 garden hose is screwed onto the shut-off valve of the reservoir and the other end is screwed onto the flush unit that has already been placed over the water intake of the lower unit of the marine engine. The lid is removed from the reservoir and the shut-off valve is opened allowing water to flow freely to the flush unit on the marine engine. The engine is cranked and allowed to run at idle speed until the reservoir is drained of water.
Due to the portability of this system, the life of many marine engines may be prolonged. In salt water operation, corrosion may severely limit the life of a marine engine. By flushing the marine engine immediately with fresh water after the engine is removed from salt water, much of the corrosion can be prevented. Prevention of corrosion is much more economical than trying to replace corroded parts.
Many marine engines are stored in remote locations that do not have a source of water. Therefore, the engines are not cranked frequently which can cause inadequate lubrication of internal parts. By using this portable system, the engine can be operated more frequently, and this will allow lubrication of the internal parts.
Finally, many marine engines may require additional care by flushing with other chemicals. Chemicals can easily be added directly to the five gallon reservoir for flushing. Chemicals may be needed to assist with winterizing a marine engine or to alleviate algae problems, etc. This is a very portable and effective means of flushing marine engines.
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A portable flushing device for a marine engine, which comprises a reservoir for temporary water storage and a delivery system to the marine engine. The power source for this system is gravity, which allows it to be portable.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to, and claims priority from, U.S. provisional application 61/044,988 filed on Apr. 15, 2008 by Michael A. Paluszek and Pradeep Bhatta entitled “VERTICAL AXIS WIND TURBINE USING INDIVIDUAL BLADE PITCH AND CAMBER CONTROL INTEGRATED WITH A MATRIX CONVERTER”, the contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to improvement of energy extraction efficiency of small-scale wind turbines, particularly vertical axis wind turbines, using active blade actuation and integration with matrix power converters.
BACKGROUND OF THE INVENTION
This invention relates to wind turbines. Wind turbines tap energy from the wind, and provide electrical energy that can be consumed locally or fed into the electrical grid. Wind energy contributes to the energy security of the United States and the rest of the world as an inexhaustible, domestic resource, thereby reducing dependence on natural gas, oil and other fossil fuels. The proposed invention will provide a means of distributed harvesting of this resource in an economically viable manner.
Wind turbines can be broadly classified based on the orientation of the axis of rotation of the rotor. The common type is the horizontal axis wind turbine (HAWT). This invention pertains to a vertical axis wind turbine (VAWT), which are attractive for suburban applications. While HAWTs are considered to have higher efficiency, they are sensitive to the direction of the wind, and also have a smaller range of wind speeds in which they can generate electric power. For domestic applications HAWTs tend to be too tall and often require expensive installation and maintenance. Previously developed VAWTs have low efficiencies, making them less attractive to suburban dwellers. Nonetheless VAWTs have some inherent advantages—they are insensitive to wind direction and require simpler installation. The proposed invention adds to the attractiveness of VAWTs by enabling higher efficiencies of energy extraction.
An early form of VAWT was the Darrieus turbine, described in U.S. Pat. No. 1,835,018 issued Dec. 8, 1931 to Darrieus. The Darrieus turbine has characteristic C-shaped blades that are connected at the top and bottom of the vertical axle. Its shape is commonly compared with that of an eggbeater. An improved version of the Darrieus turbine that incorporated upper and lower contours separated by radial stator vanes was described in U.S. Pat. No. 4,162,410 issued Jul. 24, 1979 to Amick. The Darrieus turbine is not widely used today because of its low efficiencies and structural problems.
More recently composite blades have been commonly used in VAWTs. U.S. Pat. No. 5,375,324 issued Dec. 27, 1994 to Wallace, et al. describes a pultruded composite blade for a Darrieus type wind turbine. The blade is a composite structure with a uniform cross-section with reinforcing fibers. A description of a self-erecting structure and erecting method is included.
Most VAWTs proposed in the past have fixed blades—blades that are fixed with respect to a support structure that attaches them to the main rotor. Guide vanes and deflector flaps are used to direct the wind, as described in U.S. Pat. No. 6,942,454 issued Sep. 13, 2005 to Ohlmann. There have been recent developments in creating systems that allow pivoting motion of blades, thereby enabling individual blade pitch control. U.S. Pat. No. 6,688,842 issued Feb. 10, 2004 to Boatner describes a vertical axis wind turbine having “free-flying” airfoils that self pivot according to the local dynamic conditions to which they are subjected. The motion of the airfoil about their axis is restricted to remain within limits set by stop mechanisms. The airfoil is allowed to passively—i.e., driven entirely by ambient wind conditions—pivot between a radially aligned and tangentially aligned limit. Another example of a passively controlled variable pitch vertical axis wind turbine with pitching motion constrained by stops is described in the U.S. patent application Ser. No. 11/475,459 by Jonsson.
Passive pitch control schemes generally enable better conversion of wind energy. U.S. Pat. No. 5,676,524 issued Oct. 14, 1997 to Lukas describes a VAWT having a “control plate” that can move with respect to the support structure along grooves for effecting pitch control. But allowable relative motion is restricted.
Power generation using an actively controlled blade pivoting motion can be more efficient. U.S. Pat. No. 4,247,253 issued Jan. 27, 1981 to Kazuichi Seki, et al. considers the use of active aerodynamic control for controlling the speed of a vertical axis wind turbine only for starting and braking (at excessive wind speeds) purposes. A mechanism for using spoilers for variable power control by regulated movement was presented in U.S. Pat. No. 4,500,257 issued Feb. 19, 1985 to Sullivan. U.S. Pat. No. 5,503,525 issued Apr. 2, 1996 to Brown, et al. describes a blade assembly for a vertical axis wind turbine that comprises of blades that can pivot about another vertical axis. It also describes that such a blade assembly, equipped with a wind direction measurement device and a shaft encoder, can include a control system to regulate the blade angle so that the lift component of the aerodynamic forces on the blade contributes positively to the driving torque on the rotor. However, it does not describe a specific strategy for implementing active control. U.S. Pat. No. 7,189,050 issued Mar. 13, 2007 to Taylor, et al. describes a method of increasing the efficiency of a vertical axis wind turbine through generation of a low-pressure area on a leading face of a rotor blade by using multiple stators.
Thus, there is a need for a system that improves the efficiency of power extraction capability of vertical axis wind turbines by integration of pitch, camber and generator control, and that enables efficient power extraction at any wind speed. Moreover, there is a need for a vertical axis wind turbine system that calibrates power extraction efficiency as a function of wind speed and pitch and camber control.
SUMMARY OF THE INVENTION
An aspect of the present invention provides a new vertical axis wind turbine that employs active control of individual blade pitch and camber, integrated with generator control. The wind turbine incorporates mechanisms that enable independent pitching of individual blades, and each blade is equipped with flaps that can be independently regulated for optimal camber control. A matrix converter is used for converting the variable frequency voltage generated by the wind turbine to single-phase or three-phase constant frequency voltage that will allow local use of power generated or interfacing with the electric grid.
Another aspect of the present invention provides a vertical axis wind turbine which includes a vertically-mounted shaft connected at a lower portion with an electrical generator and connected at an upper portion with one or more arms each for connecting one of a plurality of blades. The electrical generator is controlled by a generator control, and each blade also includes a pitch control for controlling the blade's pitch, which, in turn, is connected to a pitch control motor. Each blade further includes a camber control for controlling the blade's camber, which is connected to a camber control motor. In operation, the blade pitch and camber controls are integrated with the generator control.
Another aspect of the present invention includes the vertical axis wind turbine, wherein the camber control motor controls the blade's camber by rotating a flap hinge attached to a trailing edge of the blade, or, alternatively, wherein the camber control motor controls the blade's camber by elastically changing the shape of the blade.
Yet another aspect of the present invention includes the vertical axis wind turbine, in which the electrical generator uses permanent magnets in a Halbach configuration.
A telemetry collector for collecting operating telemetry and forwarding collected telemetry to a user using a wireless interface is also provided.
Another aspect of the present invention includes the vertical axis wind turbine integrated with a matrix converter.
In another aspect of the present invention, a vertical axis wind turbine system is provided which includes a plurality of vertical axis wind turbines in communication with a central controller for coordinating operation of the plurality of vertical axis wind turbines.
In another aspect of the present invention, a method of optimizing the efficiency of operation of a vertical axis wind turbine is provided. The method includes changing the blade pitch and camber in a fixed sequence and measuring the output torque, using the wind speed indication to compute lift and drag coefficients, and using these coefficients optimize blade positioning.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating a vertical axis wind turbine using individual blade pitch and camber control integrated with a matrix converter, in accordance with an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating a typical system installation, in accordance with an embodiment of the present invention;
FIG. 3 is a diagram illustrating a blade, in accordance with an embodiment of the present invention;
FIG. 4 is a flow chart illustrating processing of data and control by the controller; in accordance with an embodiment of the present invention;
FIG. 5 is a cross-sectional view of a typical generator, in accordance with an embodiment of the present invention;
FIG. 6 is a diagram depicting an exemplary generator winding configuration, in accordance with an embodiment of the present invention;
FIG. 7 is a circuit diagram depicting a realization of the matrix converter system, in accordance with an embodiment of the present invention;
FIG. 8 is a circuit diagram depicting a realization of the clamp circuit of the matrix converter, in accordance with an embodiment of the present invention; and
FIG. 9 is a circuit diagram depicting a realization of an input filter of the matrix converter, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
In the following description, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one having ordinary skill in the art, that the invention may be practiced without these specific details. In some instances, well-known features may be omitted or simplified so as not to obscure the present invention. Furthermore, reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Although every reasonable attempt is made in the accompanying drawings to represent the various elements of the embodiments in relative scale, it is not always possible to do so with the limitations of two-dimensional paper. Accordingly, in order to properly represent the relationships of various features among each other in the depicted embodiments and to properly demonstrate the invention in a reasonably simplified fashion, it is necessary at times to deviate from absolute scale in the attached drawings. However, one of ordinary skill in the art would fully appreciate and acknowledge any such scale deviations as not limiting the enablement of the disclosed embodiments.
The present invention advantageously provides for a vertical axis wind turbine to start up by itself and to operate at low wind speeds. It also provides for the integration of pitch, camber and generator control to improve the efficiency of power extraction capability of vertical axis wind turbines. It also enables efficient power extraction at any wind speed, and permits the turbine to operate at very high wind speeds without damage.
An embodiment, 10 , of the invention is shown in FIG. 1 . This figure shows three blades but any number of blades can be used, from one blade to numbers greater than or equal to two.
Pitch control of the blades is achieved using a motor 12 . This allows the blades to be oriented optimally with respect to the wind. Motor 12 may be a servo-motor or a stepping motor.
The camber of the blades is changed using a motor 14 . Motor 14 might simply rotate a flap hinge or might elastically change the shape of the blade to effect a change in camber. This changes the aerodynamic lift and drag coefficients of the blade. The change in camber is coordinated with the change in pitch to produce the desired torque in any wind condition. Again, the motor may be a servo-motor or a stepping motor. If the blade is deformable it may be one of any number of piezoelectric or other shape-change inducing actuators, without limitation.
The blades are attached to an arm which separates the blades to provide the desired swept area. One, two or more blades may be used. Power extraction increases incrementally with more blades, albeit with added cost and complexity. The incremental improvement in power extraction decreases with the number of blades. Component 16 is the arm that connects each blade to the central core in an embodiment of the invention. This arm may be located below, above or at any position along the blade elements. Multiple arms may be used for each blade. For example, one may be located at the top and one at the bottom. The number and location of arms is dependent on the length and stiffness of the blades.
In an embodiment of the invention, camber and blade pitch are modified as a function of the angle of the arm on which the blades are affixed, and of the wind speed and direction. In order to do this, the wind velocity vector is first determined. This may be done with device 18 , which is the wind velocity and direction sensor. Many types of sensors can be used, including a simple weathervane with propeller, as well as more sophisticated ultrasonic sensors, without limitation.
Preferably, the arms are connected to a central hub 20 , to which each arm is attached. This hub 20 may be a separate piece or may be a single piece in combination with connector component 16 .
In operation, the motor 14 actuates component 22 , the trailing edge flap, which is used to change the blade camber. Component 22 need not be a discrete element, and may instead be a deformable element.
Component 24 is the main part of the blade. In an embodiment of the invention, along with the trailing edge flap 22 , component 24 forms the complete airfoil. Changing the shape of the airfoil changes the camber thus changing the lift and drag coefficients. The combined length of components 22 and 24 is chosen to optimize the aerodynamic performance of the system.
Mechanical bearings provide low friction rotation of the shaft. Unit 26 is the bearing assembly that connects the generator to the shaft. Use of low friction bearings are preferable, although not an absolute requirement.
The generator has multiple windings organized into electrical phases. Three phases produces maximal efficiency. Electrical connector 28 is the multi-phase wiring that connects the generator to the drive circuits.
Mechanical connector 30 is the shaft that connects the hub to the generator.
It is also preferable for generator control that the angle of the generator shaft be known. Device 32 is an angle encoder, which may be used to measure the angle of the generator shaft.
During operation, the electrical generator converts the rotational torque into power. In an embodiment of the invention, units 34 , 36 and 38 make up the electrical generator. The preferred embodiment depicted in the drawings shows an axial flux generator, although use of a radial flux generator is alternatively envisioned.
Component 34 is the magnet assembly in the axial flux generator. The permanent magnets are arranged in a pattern to produce the desired flux in the air gap. This pattern could be in a Halbach configuration. A Halbach magnet array has a variable magnetic pole direction as a function of angle around the shaft. This keeps the magnetic flux in the air gap. The Halbach configurations produce a higher flux per magnet and eliminates the need for magnetic steel, thus lowering the mass and cost of the generator. Two magnet assemblies are used to produce a higher flux and to keep the magnetic field within the air gap. A single magnet assembly is also possible.
Component 36 is the coil assembly in the air gap. The coils may be wound in any number of phases, but three are typical.
In an embodiment of the invention, the magnets are affixed to the rotating shaft by means of structural component 38 . This component provides structural support and maintains the desired air gap thickness.
The matrix converter 40 is an electrical unit providing control circuitry for the generator. The output may be single phase or multi phase. In an embodiment of the invention, six semiconductor switches are organized into pairs for bidirectional switching as required per phase. These may be MOSFETs for low power wind turbines and Integrated Gate Bipolar Transistors (IGBTs) for high power turbines. Each phase of the generator may be connected together in either a delta or a Y configuration. The configuration may be fixed or chosen actively depending on the operating condition of the generator. The output of unit 40 is an AC voltage. No DC link is required.
The generator requires high speed control since switching speeds of 1 kHz to 20 kHz are required for the matrix converter. In an embodiment of the invention, electronic unit 42 is the circuit that controls the generator. This consists of a digital signal processor and interface electronics. The interface electronics connect to the switches of the MOSFETS or IGBTs. The digital signal processor takes commands from the control computer 44 and current readings from the generator itself.
The overall control of the system may be accomplished with a central control computer. For example, in an embodiment of the invention, device 44 is the control computer. It takes in readings of generator current, angle encoder readings, and wind measurements to generate commands for the blade pitch and camber and for the generator. The control algorithms optimally select these commands to maximize power output in all wind conditions while minimizing stresses on the system. The control computer can connect wirelessly using IEEE 802.11 to any WIFI enabled computer. Other wireless standards can also be employed, without limitation.
Electrical connector 46 is the interface to the sensors and the actuators for the blades.
In an embodiment of the invention, the AC output is connected to the grid. Electrical component 48 is a grid-tie interface that takes the AC voltage and feeds it to the electrical grid. It includes all safety devices, such as disconnects, required by the local power company.
Device 50 is the computer of the wind turbine operator that takes data wirelessly from the control computer 44 to monitor the performance to the system. Device 50 may be any type of computer or processor board with a WIFI connection. Signal 52 represents the wireless link.
FIG. 2 shows an exemplary installation of the system in a home 54 . The mounting support 56 connects the generator base to the house. Electrical connector 58 is the DC cable from the rectifier to the grid-tie inverter 62 , which connects to the circuit-breaker panel 64 and to the grid 60 .
FIG. 3 shows exemplary details of the blade assembly. Component 22 is the trailing edge flap which is used to change the blade camber. Component 24 is the main part of the blade. The flap motor 14 is embedded in the flap and attached to the base that also connects to the main part of the blade 24 . The pitch motor 12 drives the entire assembly.
FIG. 4 shows an exemplary block diagram of the controller interface. Block 1 is the master controller which controls all other blocks. Block 1 also coordinates the activities of the generator controller 7 , the rectifier controller 6 , the blade pitch control 12 , and the camber drive 13 , and sends telemetry to the telemetry block 3 and accepts user commands. Periodically, or on user command, block 1 puts the wind turbine into a calibration cycle 5 . The master controller 1 can interface with other wind turbines via this interface and coordinate their operation if a user owns multiple wind turbines. When a matrix converter is being used the master controller integrates the matrix converter switching functions with the individual blade control by feedforwarding blade control laws and wind velocity estimates to the matrix converter controller.
The user may interact with the system via block 2 , which accepts user commands through the wireless interface 4 . This permits the user to use any personal computer to talk to the wind turbine to control the operation of the turbine. In an embodiment of the invention, this can be done using a Virtual Private Network (VPN).
Information needed to monitor the operation of the system is collected in block 3 , which is the telemetry processing interface. It collects data on the various subsystems of the wind turbine and sends them via the wireless interface 4 to the user. This permits the user to monitor the performance of the turbine and its health.
In an embodiment of the invention, standard WiFi, IEEE 802.11 is used for communication by the wireless interface in Block 4 . The wireless communication is encrypted so that only the owner can receive data or send commands. The generator may be connected to a VPN for security.
When the system is put into service or when problems are encountered, it may be necessary to recalibrate the wind turbine, which can be done through the calibration controller, block 5 . During calibration the controller changes the blade pitch and camber in a fixed sequence and measures the output torque. Using the wind speed indication it computes the lift and drag coefficients so that the control system can optimize blade positioning. The calibration can be initiated on user command 2 or automatically. The generator may still produce power during calibration but it will not be the maximum possible power. During startup of the system, and for a period of time after startup, the turbine will switch into calibration mode at different wind speeds so that a table of lift and drag coefficients vs. wind speed can be generated. Over the life of the wind turbine this will be done to re-calibrate the wind turbine as it ages.
It is necessary to monitor the grid to determine if the wind turbine is properly interfacing with the grid. This is done in block 6 .
Generator control is accomplished by commanding the switching of the matrix converter. Block 7 is the generator control. This controls the switching of the matrix converter. It communicates with the digital signal processor (DSP).
In an embodiment of the invention, the generator is controlled by a DSP. Block 8 is the interface to this DSP. This formats the generator control commands into the data words that the generator control chip accepts.
In operation, the wind sensor produces a 3-dimensional wind vector. Block 9 is the interface to the wind sensor, which measures wind direction and speed. The wind sensor vector is read in here and formatted for use by the control system.
The grid interface is in block 10 . It collects grid data, including voltage, current and frequency, and formats it so that it can be used by the control computer.
Current measurements may also be used to control the generator. Block 11 is the interface to the generator current sensing. It reads in the data and formats if for use by the generator controller.
Motor interfaces are in block 12 and block 13 . Block 12 is the interface to the pitch axis drive. This takes the pitch angle commands and formats it either into steps for a stepping motor or servo commands for a servomotor. Block 13 is the interface to the camber drive. This takes the pitch angle commands and formats it either into steps for a stepping motor or servo commands for a servomotor. If the camber control is a shape control it will send the shape command to the electronics that determines the blade shape.
The generator needs to know its angle to determine switching times. This is done via an angle encoder or other angle sensor. Block 14 is the angle sensor. It reads in angle encoder data and formats it for use by the control system.
FIG. 5 shows details of an exemplary generator. Mechanical component 70 is the shaft attached to the blade assembly which is attached to the two disks 66 , 68 with the permanent magnets. Component 74 is the stator and winding 72 . Alternative generators may be employed, without limitation.
FIG. 6 shows details of an exemplary winding assembly. Three phase windings may be realized using winding pattern 76 .
FIG. 7 shows details of an exemplary matrix converter assembly. The matrix converter is an array of controlled semiconductor switches that can be used to convert variable frequency input to a variable output voltage with a specified, constant frequency. It does not have any dc-link circuit and does not need any large energy storage elements. Components 80 , 82 and 84 show the three phase coils in the generator. Components 86 and 88 are two anti-paralleled NPT-IGBTs with reverse blocking capability. Together they form a semiconductor bidirectional switch. The clamp circuit provides overcurrent/overvoltage protection.
FIG. 8 shows the realization of a clamp circuit. For a 3phase-to-3phase matrix converter, the clamping circuit is realized using 12 fast recovery diodes 96 and a clamp capacitor 98 . The input filter minimizes the high frequency components in the input currents and reduces the impact of perturbations of input power.
FIG. 9 shows the realization of an exemplary input filter using an inductor 100 —capacitor 102 combination, with parallel damping resistor 104 .
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
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A vertical axis wind turbine that can be actively controlled is provided. This invention includes mechanisms and methods for enabling high-efficiency wind energy extraction by a vertical axis wind turbine using active pitch and camber control of individual blades. Blade control is further integrated with generator control and power electronics. Integrated control algorithms are systematically constructed, and transmitted to the wind turbine through a wireless communications interface. The interface also allows the user to continuously monitor the state of the wind turbine system. This invention includes sensors and procedures for periodic self-calibration of wind turbine parameters for preserving the long-term efficiency of wind energy extraction. Furthermore, a capability to intelligently interact with other wind turbine systems in a wind-farm setting is incorporated.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/390,711, filed Mar. 19, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a digital message display for vehicles, and particularly to a digital message display for vehicles having a sensing means to detect when a trailing vehicle is following too closely for the purpose of automatically displaying a message to the trailing vehicle.
[0004] 2. Description of the Related Art
[0005] Digital message displays are well known, and have been employed in advertising signs, message boards or displays often seen in bars and restaurants, and a wide variety of commercial settings. Such displays are frequently used to promote sales, upcoming special events, and the like.
[0006] Digital message displays have also been used on vehicles. Used on vehicles, these displays often show commercial messages. Also, digital message displays have been used to offer greeting and safety messages to the drivers and passengers of other vehicles. U.S. Pat. No. 5,825,281, issued on Oct. 20, 1998 to R. McCreary, describes a method of displaying advertising messages. A digital message display shows one of a number of pre-defined messages. Each time the brake pedal is depressed, the message display is changed. The display, mounted on the top or the rear of a vehicle, conveys advertising messages to other vehicles, pedestrians, and others who happen to see the vehicle.
[0007] Another system that employs a vehicle-mounted digital display for commercial and advertising purposes is detailed in U.S. Pat. No. 6,060,993, issued on May 9, 2000 to E. Cohen. This system uses a wireless communication system, along with a GPS system, to display messages on command form a base station or based on geographic relevance as the vehicle moves between different locations.
[0008] U.S. Pat. No. 5,500,638, issued on Mar. 19, 1996 to I. George, discloses a vehicular goodwill message system that is intended to issue a message on command from the operator of a vehicle. The system allows for the display of four pre-defined messages including courtesy messages such as “SORRY!” or “THANK YOU!” that may be signaled to a trailing driver, and distress messages such as “PLEASE HELP” or “PLEASE CALL 911”. A control box includes a pushbutton for each message.
[0009] U.S. Pat. No. 5,905,434, issued on May 18, 1999 to P. Steffan, shows a vehicle communication device that is another example of a message display that allows the driver of a vehicle to select from a number of preset and pre-programmed messages to be displayed on a display device mounted on the exterior of the vehicle.
[0010] In addition to the commercial benefit of advertising signs, and the entertainment and courtesy value of messages that a driver might signal to a following vehicle, it is desired to use a vehicle mounted digital display to improve vehicular safety. Rear-end accidents while driving account for a significant number of all vehicle accidents. These may be caused, among numerous factors, by a driver following another vehicle too closely, or by the driver of a following vehicle simply being inattentive to the actions of the vehicle in front.
[0011] U.S. Pat. No. 6,300,870, issued on Oct. 9, 2001 to W. Nelson, discusses safety aspects in an automotive digital rear window display. The primary safety feature discussed, however, is merely that the message display may capture the attention of a following driver more quickly than conventional means such as the vehicle brake lights or the turn signals.
[0012] While the display may indeed capture the attention of the following driver, it is not helpful if the leading driver is unaware of, and therefore cannot display a message in response to, a hazardous situation such as a tailgater.
[0013] None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a digital message display for vehicles solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0014] The digital message display for vehicles is a digital message display, to be mounted in the rear window of an automobile, capable of displaying a number of pre-defined messages. Distance measuring sensors are mounted on the automobile's rear bumper to detect and determine the distance to a following vehicle. A computer processing unit, containing a program memory, is electrically connected to the display and the sensors and will cause a pre-determined message to be displayed when a following vehicle becomes too close. The system also has a remote control that may be used to show other courtesy messages on the display. An audible alarm and a distance display provide information to the vehicle's driver about the presence of, and the distance of, the trailing vehicle. The warning that is automatically issued to the following driver, along with the alert and distance information presented to the vehicle's driver, enhance safety and help to prevent a rear-end collision.
[0015] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A is an environmental, perspective view of a digital message display for vehicles according to the present invention.
[0017] FIG. 1B is an environmental, perspective view of a digital message display for vehicles according to a second embodiment of the present invention.
[0018] FIG. 2A is an environmental, perspective view of the remote control and distance display components of the digital message display for vehicles according to the present invention.
[0019] FIG. 2B is a perspective view of the remote control shown in FIG. 2A .
[0020] FIG. 3 is a block diagram of the message display for vehicles according to the present invention.
[0021] FIG. 4 is an environmental, perspective view showing a method of mounting a digital message display for vehicles according to the present invention.
[0022] FIG. 5 is an environmental, perspective view showing an alternate method of mounting a digital message display for vehicles according to the present invention.
[0023] FIG. 6 is a perspective view of a second embodiment of a message display in a digital message display for vehicles according to the present invention.
[0024] FIG. 7 is a cutaway view of the message display shown in FIG. 6 .
[0025] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The present invention is a digital message display for vehicles. The digital message display for vehicles is a vehicle safety device that displays a warning message on a message display 10 when a tailgating vehicle is detected by distance sensors 20 . FIG. 1A shows a digital message display for vehicles incorporating a message display 10 , disposed in a vehicle's rear window in view of following vehicles, and a first pair of distance sensors 20 mounted on the vehicle's rear bumper.
[0027] Referring to FIG. 1B , a second pair of distance sensors 21 are added. In the embodiment shown in FIG. 1B , the first pair of distance sensors 20 and the second pair of distance sensors 21 are each configured to sense trailing vehicles at a different range, either by characteristic of the sensors or by software compensation. As illustrated, the first pair of distance sensors 20 are configured to sense trailing vehicles in the vicinity of a close range distance d 1 , while the second pair of distance sensors 21 are configured sense trailing vehicles in the vicinity of a long range distance d 2 . In one configuration, a short range distance d 1 may be about three (3) meters, in conjunction with a long range distance of about ten (10) meters, although it can be recognized that other distances may be employed as well.
[0028] By employing the first and second pairs of distance sensors 20 , 21 , each configured for a different range, the digital message display for vehicles may be responsive to trailing vehicles at multiple distance thresholds to provide a first general warning message (in the vicinity of the long range distance d 2 ), and a second more urgent warning message (in the vicinity of the short range distance d 1 ). Additionally, the digital message display for vehicles may provide different thresholds to illuminate a warning message at slow driving speeds (where a closer trailing distance is tolerated) or at high driving speeds (where a greater trailing distance is required for safety).
[0029] As shown in FIG. 2A , the digital message display for vehicles includes a distance display 46 that displays the distance between the vehicle and the tailgater. A remote control 30 allows the driver to control the operation of the digital message display for vehicles, such as to select a mode of operation or to manually display additional safety and courtesy messages. Referring to FIG. 2B , a switch 32 is shown more clearly for selecting between a highway and a local mode of operation.
[0030] Referring now to FIG. 3 , a microcomputer 40 is shown in electrical connection with a pair of distance sensors 20 and with the message display 10 . The microcomputer 40 is one of a type well known in the art that contains a memory and program storage means. A microcomputer program is contained in the microcomputer 40 . The microcomputer program functions to read the distance sensors to determine the distance to a tailgating vehicle. In the illustrated embodiment, the microcomputer program reads the first and second pairs of distance sensors 20 , 21 , although it can be understood that a single pair of distance sensors may be employed to provide similar functions using a single distance range.
[0031] When the microcomputer program determines that a tailgating vehicle is present and closer than a predetermined safety threshold, the microcomputer 40 causes a warning message to be displayed on the message display 10 . A textual message such as “TAILGATING!” flashes on the message display 10 to alert the tailgating driver. The microcomputer program may operate in a local mode or in a highway mode, depending on the position of the switch 32 .
[0032] In the local mode, the microcomputer program employs primarily the first pair of distance sensors 20 to monitor trailing vehicles within the vicinity of the short range distance d 1 , at relatively close distances associated with slower driving speeds. In the highway mode, the microcomputer program employs primarily the second pair of distance sensors 21 to monitor trailing vehicles within the vicinity of the long range distance d 2 , at greater distances associated with driving at higher speeds. The microcomputer 40 may be in communication with the vehicle's speedometer, or another device for measuring the actual velocity of the vehicle to compensate, or adjust, threshold levels for activating a tailgating message. When the vehicle is stopped, or parked for example, a very low distance threshold may be employed to indicate a different message, such as a collision warning.
[0033] Additionally, a distance display 46 may be electrically connected to the microcomputer 10 . When the microcomputer program determines that a tailgater is present, the distance between the vehicle and the tailgater is displayed on the distance display 46 . In the illustrated embodiment, the distance display 46 is disposed in the vehicle's rear-view mirror. A beeper 44 , also in connection with the microcomputer 40 , emits an audible alarm to alert the driver to the tailgater's presence.
[0034] The remote control 30 may communicate with the remote control receiver 42 over a wired connection or by a wireless means such as by infrared or RF. In the case of the wired connection, the remote control 30 may communicate directly with the microcomputer 40 . In the case of a wireless interface, the remote control 30 communicates with a remote control receiver 42 that is in electrical connection to the microcomputer. 40 . In a wireless embodiment, the remote control 30 transmits an RF signal that is received by the remote control receiver 42 . The remote control 30 has a plurality of pushbuttons 31 , 33 , 35 , 57 , and 39 . When one of the pushbuttons 31 , 33 , 35 , 57 , 39 is depressed, a signal is transmitted to the remote control receiver 42 , which in turn communicates the signal to the microcomputer 40 . The microcomputer program will cause the message display 10 to display a unique predetermined message for each pushbutton that is depressed. In the embodiment illustrated, pushbutton 31 will cause the message “THANK YOU” to be displayed; pushbutton 33 displays “SORRY”; pushbutton 35 shows “SLOW DOWN”; pushbutton 37 shows “CALL 911”; and pushbutton 39 shows “TAILGATING”. Other messages could be pre-programmed in the microcomputer, but it is not intended that the messages are customizable by the users of the digital message display for vehicles.
[0035] Turning now to FIG. 4 , a method for removably mounting the message display 10 within a vehicle is shown. An elongated slide track 11 , having a “T” channel 13 defined lengthwise therein, is mounted to a rear deck D of the vehicle, adjacent to the rear window. An elongated “T” slide member 15 is fastened to the bottom of the message display 10 . The message display 10 is mounted in place by engaging the “T” slide member 15 with the “T” channel 13 of the slide track 11 .
[0036] Referring to FIG. 5 , the message display 10 is shown removably mounted to the rear deck D of a vehicle with a hook and lop fastener. A first component 17 of a hook and loop fastener is affixed to the rear deck D of the vehicle, and a second mating component 19 of the hook and loop fastener is affixed to the bottom of the message display 10 . The message display 10 may be held in place on the rear deck D of the vehicle by simply mating together the first and second components 17 , 19 of the hook and loop fastener.
[0037] Turning now to FIGS. 6 and 7 , an alternative message display 100 is fashioned on or within a vehicle rear window 108 itself, eliminating the requirement to mount a separate unit on the vehicle rear deck D. The message display 100 comprises an array of Light Emitting Diodes (LEDs) 102 disposed on the inside surface 106 of, or embedded within, the vehicle rear window 108 . The LEDs 102 are interconnected by electrical traces 104 formed on the inside surface 106 of the vehicle rear window 108 to form an alpha-numeric display. In the illustrated embodiment, the LEDs are arranged to form a dot-matrix type of alpha-numeric display.
[0038] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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The digital message display for vehicles detects a tailgater and automatically flashes a warning message, directed to the tailgater, on a message display that is located in the rear window of the vehicle in view of following traffic. In addition to the warning message directed to the tailgater, a distance display is located in view of the vehicle driver to indicate the distance of the tailgater. An audible alarm alerts the driver to the presence of the tailgater. Additionally, a wireless remote control device allows the driver to manually select and display one of a number of pre-defined safety and courtesy messages. Multiple distance sensors provide multiple functional ranges to accommodate varying driving or traffic conditions.
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This application is a continuation of application Ser. No. 07/129,368 filed Nov. 30, 1987, now abandoned; which is a continuation of application Ser. No. 06/927,869 filed Nov. 7, 1986, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an image-forming lens such as an objective or collimator lens which is used in a video disk, audio disk or optical memory apparatus, and more particularly to a distributed index image-forming lens for an optical memory which has a numerical aperture NA of not more than about 0.5 and the aberration of which in the vicinity of the optical axis is preferably corrected.
2. Description of the Prior Art
As heretofore known, the distributions of the refractive indexes of distributed index lenses are classified into three fundamental refractive index distributions: radial, axial and spherical types. The radial type is defined by a refractive index distribution which is aligned in the radial direction perpendicular to the optical axis; the axial type is defined by a refractive index distribution which is aligned in the direction of the optical axis; and the spherical type has a refractive index distribution which exhibits a spherical symmetry about a point. Many proposals for using these distributed index lenses as objective lenses for optical disks have been made, such as in Japanese Patent Laid-Open No. 122512/1983, No. 62815/1984, No. 140309/1985 and No. 172010/1985. All of these proposals relate to single lenses having refractive index distributions of the radial or axial type alone. On the other hand, an image-forming system of the spherical type is disclosed in Japanese Patent Laid-Open No. 181516/1982. This system, however, employs a specific arrangement in which a core having a spherical refractive index distribution is coated with a cladding of a uniform medium. Such an arrangement is not preferable since it is difficult to manufacture, and it cannot facilitate the correction of any aberration of the spherical lens so long as the lens has a spherical refractive index distribution and a numerical aperture NA of not more than about 0.5.
SUMMARY OF THE INVENTION
The present invention is designed to solve the above-described problems. It is therefore an object of the present invention to provide an image-forming lens that has a simple construction and a spherical refractive index distribution in which, when the numerical aperture is not more than 0.5, spherical aberration can be corrected while satisfying the sine condition.
To this end, the present invention provides an image-forming lens in the form of a plano-convex lens in which a surface γ 1 on the object side is a spherical surface and a surface γ 2 on the image side is a plane surface. The image-forming lens has a refractive index distribution N(ρ) exhibiting a substantially spherical symmetry with its center located in the vicinity of the highest point of the object-side surface
γ 1 , and which satisfies the following conditions:
(1) N(ρ)=N 0 +N 1 ρ 2 +N 2 ρ 4 + . . . . .
(2) 1.56<N 0 ≦1.63
(3) 0.35<d/f<0.60
(4) -0.25<N 1 f f <-0.20
where N 0 , N 1 , N 2 . . . are refractive index distribution coefficients; f is the focal length of the lens; d is the axial thickness of the lens; and ρ is the distance from the highest point of the object-side surface γ 1 . The relationship is obtained if it is assumed that the highest point of the object-side surface γ 1 corresponds to the origin (0, 0, 0) of a three-dimensional coordinate system; and the optical axis, meridional direction, and sagittal direction correspond to the X, Y and Z axes, respectively. Furthermore, for purposes of this specification and the concluding claims, the term "highest point" shall mean that point on the spherical surface γ 1 which is most distant from the plane surface γ 2 when measured perpendicularly from the plane surface γ 2 .
In an ordinary optical disk or optical card for a recording and/or reproducing system, the recording surface is covered and protected by a cover glass. When the image-forming lens in accordance with the present invention is designed to take into consideration the thickness t of this cover substrate, it is preferable in selecting the system specifications to set the relationship between the focal length f of the image-forming lens and the thickness t of the cover substrate so that the following inequality is satisfied:
0.03<t/f<0.50. (5)
Other features of the present invention are shown in the following description with reference to preferred embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an image-forming lens according to the present invention; and
FIGS. 2 to 5 are graphs of the aberrations of image-forming lenses which are first to fourth examples of the design of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a cross-sectional view through an image-forming lens L in accordance with the present invention and a transparent cover substrate P, for example, of an optical disk or card. The image-forming lens L has a primary surface γ 1 , a secondary surface γ 2 , a thickness d at the axis of the lens L, and a highest point 0 on the primary surface γ 1 . The cover substrate P has a thickness t. An arrow indicates the distance from the highest point 0. The curvature of the secondary surface γ 2 in accordance with the present invention is zero (radius of curvature: ∞), that is, the secondary surface γ 2 is a flat plane.
As described above, the present invention specifies that the primary surface γ 1 is provided on the object side and the secondary surface γ 2 is provided on the image side, when the lens is used to provide negative magnification. Accordingly, when the lens is used as an objective lens for recording on an optical memory such as an optical disk or card, the surface of the lens which faces the recording surface is the secondary surface, as shown in FIG. 1; and when the lens is used as a collimator lens for a semiconductor laser or the like, the surface of the lens which faces the light source is the secondary surface. As noted, the cover substrate P disposed on the image surface side may be, for example, a protective substrate of a recording medium for optical disks, or may be the beam-issuing aperture of a semiconductor laser.
In the optical path diagram shown in FIG. 1, an image is formed on one surface of the parallel-plane plate, namely, the cover substrate P, opposite to the other surface thereof facing the lens L. However, this parallel-plane plate may be disposed in the vicinity of the lens or be connected thereto, when the lens is used as a collimator lens.
Inequalities (2) to (5) for the lens in accordance with the invention are set forth below, and it is assumed that all of these inequalities are satisfied.
(2) 1.56<N 0 ≦1.63
(3) 0.35<d/f<0.60
(4) -0.25<N 1 f 2 <-0.20
(5) 0.03<t/f<0.50
Formula (1), set forth in the Summary of the Invention, represents a spherical refractive index distribution in general. Inequality (2) above indicates the condition of a refractive index N 0 at the center of the refractive index distribution in accordance with the present invention, namely the refractive index defined in the vicinity of the highest point of the primary surface γ 1 . This inequality is determined by a condition which corrects the spherical aberration and the sine condition when the secondary surface γ 2 is assumed to be a flat plane. The sine condition is a condition of constant aberration in the vicinity of image points on the axis. To satisfy this condition, it is necessary to eliminate the coma in the vicinity of image points on the axis over the entire luminous flux. The offence of sine condition, which is described below, represents the amount of deviation from the sine condition, in other word, it is a quantity which represents the occurrence of the coma in the vicinity of image points on the axis. That is, if N 0 is smaller than the lower limit value in Inequality (2), the offence of sine condition (hereinafter referred to as the O.S.C.) is negative at the part thereof which is of a high order and therefore causes introverted coma. If N 0 is larger than the higher limit value, the O.S.C. is positive and hence causes extroverted coma. Inequality (3) indicates the condition of the thickness d on the axis of the lens and at the same time indicates a condition wherein the spherical aberration and the sine condition are corrected, along with a condition in which the edge thickness of the lens is adequately set. If d/f is smaller than the lower limit value in Inequality (3), a part of the O.S.C. is negative and the edge thickness of the lens is reduced, thus making it difficult to set NA at 0.45 to 0.5. If d/f is larger than the upper limit value, the O.S.C. is positive. Inequality (4) indicates the condition of a distribution coefficient N 1 which determines the basic distribution form of the refractive index distribution N (ρ). The spherical aberration and the O.S.C. are positive if N 1 f 2 is smaller than the lower limit in Inequality (4), and they are negative if N 1 f 2 is larger than the upper limit. Inequality (5) defines a condition relating to the thickness t of a parallel-plane plate such as the cover substrate P, and is determined by a thickness 1.0 to 1.5 mm for an ordinary optical disk plate, a focal length of 3 to 6 mm for an objective, a thickness of 0.5 to 1.5 mm for the emergence aperture portion of a semiconductor laser and a focal length of 8 to 16 mm for a collimator lens.
If, in Inequality (5), t/f is smaller than the lower limit, the thickness of the lens is so reduced in accordance with the conditions of the aberration correction that a proper value of NA cannot be obtained. Therefore it is impossible to use the lens as an objective. If t/f is larger than the upper limit, the thickness of the lens is increased too much for an adequate movable distance and a suitable interval between the light source and the lens to be set.
Thus, the invention can provide an image-forming lens with a simple construction including one flat surface, the NA of which is not more than 0.5 and the aberration of which is properly corrected, when the Inequalities (4) to (5) are satisfied.
The spherical refractive index distribution in accordance with the present invention can be provided in substantially the same manner as that in the case of microlenses, such that a spherical blank undergoes ion exchange or a blank in the form of a plane plate is covered by a mask having very fine holes and thereafter undergoes processing by a field-introducing method or the like, thus forming the refractive index distribution. It is also possible to employ a suspension polymerization method made public in the 32nd Applied Physics Associated Lecture Meeting (Oyo Busturigaku Kankei Rengo Koenkai), spring 1985.
The examples of the values defining the image-forming lens in accordance with the present invention will now be described below. The refractive index distribution formed in this image-forming lens can be represented by the above-mentioned formula (1) with, as a parameter, distance from the origin 0, which is assumed be the highest point 0 of the primary surface γ 1 of the lens. This representative formula has been determined for convenience sake, and it does not exclude other forms.
Tables 1 to 4 show lens data, refractive index distributions and items of other related data on the first to fourth examples of the image-forming lens provided in accordance with the present invention. In these tables, f represents the focal length; γ 1 and γ 2 ,the curvatures of the primary and secondary surfaces; NA, the numerical aperture; d, the axial thickness; N 0 , the refractive index in the vicinity of the highest point of the primary surface; N 1 the refractive index distribution coefficient; t, the thickness of the cover substrate P; and ηt, the refractive index of the substrate P. In each example, the refractive index distribution coefficients N 2 , N 3 . . . are all set at zero.
TABLE 1__________________________________________________________________________f NA γ1 γ2 d N.sub.0 N.sub.1 t ηt__________________________________________________________________________4.5 0.5 3.2173 ∞ 1.93 1.5951 -1.09734 × 10.sup.-2 1.2 1.4855__________________________________________________________________________
TABLE 2__________________________________________________________________________f NA γ1 γ2 d N.sub.0 N.sub.1 t ηt__________________________________________________________________________4.5 0.45 3.22133 ∞ 2.45084 1.57 -1.08943 × 10.sup.-2 1.2 1.4855__________________________________________________________________________
TABLE 3__________________________________________________________________________f NA γ1 γ2 d N.sub.0 N.sub.1 t t__________________________________________________________________________4.5 0.5 3.23455 ∞ 1.90328 1.6 -1.9464 × 10.sup.-2 1.2 1.4855__________________________________________________________________________
TABLE 4__________________________________________________________________________f NA γ1 γ2 d N.sub.0 N.sub.1 t t__________________________________________________________________________4.5 0.5 3.23646 ∞ 1.72694 1.61 -1.09514 × 10.sup.-2 1.2 1.4855__________________________________________________________________________
FIGS. 2 to 5 show the aberration diagrams of the image-forming lenses of the first to fourth examples. In these drawings, S.A. represents the spherical aberration and O.S.C. represents the offence of sine condition. As shown in each aberration diagram, both the spherical aberration and the sine condition are properly corrected so as to ensure appropriate image-forming performance for this kind of lens system.
These examples are designed to satisfy the above condition formula (1) and condition inequalities (2) to (4) while being compatible with the relationship defined by the condition inequality (5). Other various image-forming lenses can be provided by formulating designs in consideration of the specification and the purpose of the devices in question using such lenses so as to satisfy the above-described conditions (1) to (4). Since the present invention specifically provides a lens in the plano-convex form, the lens is readily manufactured and, when the refractive index distribution is formed by the above-mentioned techniques, it becomes suitable for mass production.
As described above, the present invention provides the lens in the form of a plano-convex lens with a spherical refractive index distribution which can be readily manufactured with a simple construction, ensuring that any aberration in the vicinity of the axis of the lens can be properly corrected as long as the NA of the lens is not more than 0.5. The lens in accordance with the present invention is highly effective when used as an objective lens for an optical memory device and as a collimator lens for a semiconductor laser.
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An image-forming lens having a primary surface defined by a spherical surface and located on the side of an object when the lens is used to provide negative magnification, a secondary surface defined by a flat plane and located on the side of an image, the lens having therein a refractive index distribution exhibiting a substantially spherical symmetry with its center located in the vicinity of the highest point of the primary surface located most distantly from the secondary surface when measured perpendicularly from the secondary surface.
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TEECHNICAL FIELD
[0001] The present invention relates to processes and means by which multiple computers in networked systems are enabled to make available and/or exchange information. The invention is particularly directed at provision of an integrated system for access to and use of information by any one or more of multiple computer systems without requiring specifically programmed responses or requests in or from the distinct systems.
BACKGROUND OF THE INVENTION
[0002] Enabling multiple computer systems to work effectively in sharing information and resources accounts for a substantial proportion (possibly 80%) of current work in the integration of computer systems. For example, a system in a retail bank may hold information relating to a customer's account, while quite a different system (such as a telephone switch) may hold more transient information regarding the source of origin of a customer's call. Making these separate systems work together (so as, say, to display the customer's account details on a screen using the telephone caller line ID as a key) presently involves using hardware and software to program each participating system to communicate specifically and directly with each other to achieve the desired result. The problem with this approach is that the complexity of the integration rises rapidly as the number of systems to be integrated increases. Furthermore, the specific programming skills required may become difficult to acquire and retain as individual integrated systems become older or even obsolete.
[0003] Attempts to address these problems have led to the development of “Information Brokers” or “Message Oriented Middleware” which enable one system to connect to another, often via an intermediary hub. This offers a considerable improvement because each integrated system requires only to be connected to the hub rather than to each of the other systems involved in the integration. Furthermore, the complexities of ensuring that messages arrive in the correct order at the recipient system, the queuing of messages so that temporary unavailability does not affect the overall integration, and the distribution of messages to multiple “subscribing” systems can all be handled within the message oriented middleware. An example of an existing message queuing system is described in U.S. Pat. No. 4,333,144 entitled “Task communicator for multiple computer system”.
[0004] One central problem with this approach, however, is that each system, being an “end point” in the integration, needs to be specifically programmed in the light of the operations to be done preceding and subsequent to the transmission of each message or batch of messages between systems. These operations have to be programmed in the light of and with knowledge of the equivalent operations of other integrated end points. As the number of integrated systems increases, this work becomes overwhelmingly complex. Automatic integration—that is, enabling systems of all kinds to work together without the need to explicitly program or re-program each system in every new case is not facilitated in this environment.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention provides an improved method and apparatus for information routing and sharing in multiple computer networks, which can facilitate automatic integration of diverse network and data systems, and users and sources of information.
[0006] In one aspect, the invention provides a method of facilitating the exchange and processing of information in and between a plurality of Blocks, wherein each Block is an information-providing or information-processing element in an integrated data network, and further wherein at least one Block has a requirement for receiving information from one or more other Blocks. The method includes:
[0007] (1) providing an Information Routing Layer to manage the exchange of information between Blocks and the fulfilment of a specific Information Request from a Block having a requirement to receive information; wherein (a) each Block which can provide or process information on the network is registered at the Information Routing Layer; (b) each unit of information is handled in the Information Routing Layer as a Field within a Dataset uniquely identified and associated with the Block first responsible for providing information in such Dataset;
[0008] (2) on receipt of an Information Request specifying at least one Field, the Information Routing Layer operates to match each requested Field with a Proper Set comprising a corresponding Field (or Fields) selected from an available Dataset or Datasets.
[0009] In a multiple computer system, distinct information users and sources may be considered as “Blocks” in an integrated data network. Such “Blocks” may therefore comprise an individual computer or transducer or may comprise multiple devices or an entire local area network which can effectively function as an individual data user or source within the wider integrated data network. Depending upon circumstances, a Block may act as an information-providing or as an information-processing element, or as both.
[0010] Preferably, where one or more Blocks have an information processing capability to produce one or more specified output Fields when provided with one or more specified input Fields, this capability is recorded in the Information Routing Layer in the form of an Exchange Set for each Block with said capability specifying the input and the output Field(s) for each such Block, and the Information Routing Layer is adapted to form an Aggregate Set of one or more Fields from an available Dataset or Datasets with one or more of said Exchange Sets so as to enable the fulfilment of a specific Information Request.
[0011] An Information Routing Layer provides for the routing of information stored in the form of Datasets (combinations of field names, types, values and other components) from one Block to another by the process of “Information Routing”, such that an existing Dataset can be provided or an Aggregate Set can be constructed using available Exchange Sets where appropriate to meet an Information Request from a Block in the integrated data network without programmatic or specified workflow reference to other Blocks. This latter feature, in particular, gives the present invention the advantages of straightforward scalability, resilience and generic applicability.
[0012] In a corresponding physical aspect, the invention provides an Information Router for facilitating the exchange and processing of information in and between a plurality of Blocks. Each Block is an information-providing or information-processing element in an integrated data network (and could generally include a District or any other defined data unit). At least one Block has a requirement to receive information from one or more other Blocks. The Information Router includes one or more computer processor(s) programmed to manage the exchange of information between Blocks and the fulfilment of a specific Information Request from a Block having a requirement to receive information. Each Block which can provide or process information on the network is registered by the Information Router. Each unit of information is handled by the Information Router as a Field within a Dataset uniquely identified and associated with the Block first responsible for providing information in such Dataset. On receipt of an Information Request specifying at least one Field, the Information Router will operate to match each requested Field with a Proper Set, which is a corresponding Field (or Fields) selected from an available Dataset or Datasets.
[0013] Preferably, where one or more Blocks has an information processing capability to produce one or more specified output Fields when provided with one or more specified input Fields, the Information Router is programmed to record such capability in the form of an Exchange Set for each Block with such capability specifying the input and the output Field(s) for each such Block, and in operation to form an Aggregate Set of one or more Fields from an available Dataset or Datasets with one or more of said Exchange Sets so as to enable the fulfilment of a specific Information Request.
[0014] The process of Information Routing for automating the integration of diverse electronic and computer components and systems, data users and sources may be performed by one or more specific hardware devices or a combination of hardware and software or by programmed instructions using conventional processors to perform “Information Router” functions. The principal function of the Information Routing Layer is to enable information from any Block to be made available to any other Block or to specified categories of other Blocks as appropriate.
[0015] The Information Routing Layer provides the facility for a Block to offer or convey information onto the network, to make requests for information, and to exchange new information in return for existing information.
[0016] Information Routing may take place at different levels in an integrated data network. For Blocks that belong to a particular bounded infrastructure (a “District”), such as a local data network, within which Information Routing is required, a single Information Router can act as the intermediary substrate (real or virtual) by which information is routed. On a wider network, Blocks may themselves belong to separate Districts. In this case, each District may have its own Information Routing Layer, with an additional link provided between the individual Districts to enable Information Routing at the District level.
[0017] Information Routing may be implemented on top of conventional data network protocols, such as TCP/IP with or without a separate message passing and queuing facility at the underlying Data Routing level. In a preferred embodiment of the present invention, Information Routing is implemented at the application Layer 7 of the OSI 7 -layer data networking model.
BRIEF DESCRPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a block diagram illustrating the relative hierarchy of Data Routing level, Information Routing Level, Districts and Blocks in an integrated data network adapted to exploit the invention;
[0019] [0019]FIG. 2 is a block diagram showing elements included in an example Dataset;
[0020] [0020]FIG. 3 is a flow chart showing the basic processes involved in Information Routing according to the invention;
[0021] [0021]FIG. 4 is a flow chart showing the processes involved in the formation of an aggregated Dataset;
[0022] FIGS. 5 to 8 illustrate the principal stages in application of the present invention to a telephone call-centre environment; and
[0023] [0023]FIGS. 9 and 10 illustrate how the application of the invention as used in the callcentre example can automatically adapt to the addition of a new information processing Block (a Call Logger) to the data network in that example.
DETAILED DESCRIPTION OF THE INVENTION
[0024] [0024]FIG. 1 illustrates key elements of an integrated data network embodying features according to the present invention. The integrated network is divided into Blocks 1 , which represent individual information-processing or information-providing elements (users and/or sources of information), in the network. As such, each Block represents an individual computer, a local network, a transducer or a combination of such entities which can act or be treated as a unitary “Block” within the integrated data network. In FIG. 1, two Blocks in each case form a local District 2 and information is routed between Districts via the Information Routing Layer (“IRL”) 3 , which connects them for that purpose. All data connections among the Blocks 1 , Districts 2 and IRL 3 are well-known wired or wireless connections. Additional Information Routing Layers 3 A, shown in dashed lines, could also be provided at each District level to route information directly between Blocks in the same District. The Information Routing Layer 3 is preferably implemented in the application layer above the basic underlying data network-layers 4 in accord with the well-known OSI 7-layer model, where data is transferred using the conventional network protocols such as TCP-IP.
[0025] In the embodiment illustrated, the Information Routing function is implemented at network application level (as an “Information Router”) and allows collections (“Datasets”) of units of information (“Fields”) contributed by one or more applications, data users or sources (“Blocks”), to be formed in order to satisfy the requirements for inter-Block information sharing or exchange. FIG. 2 illustrates diagrammatically the typical elements which can be included within an example Dataset. Fields 1 to ‘X’ contain data which may be provided or processed by a Block. A Field is made up of at least an identifier (“Field Identifier”) which will be unique within a Dataset, and a value (“Field Value”). The Field Value may be a traditional programmatic data type such as integer, float or string. It may also be a data type such as uniform resource locator, or a proprietary file format such as that for a commercial spreadsheet. A Field is always contained in a Dataset. A Dataset always has a unique label.
[0026] A Dataset will also normally have one or more “Attributes” which can be used by the Information Routing Layer for process management functions. Typically, “Attributes” may include the time of creation of the Dataset, an identifier of the Block which first provided the Dataset and an indicator if the Dataset is in an extant Aggregate Set.
[0027] Additionally, the Dataset may include details of the Field(s) supplied in response to one or more Information Requests.
[0028] The Information Router provides a single programmatic interface for the benefit of participating Blocks via a programming library or similar facility. The Information Router supports the basic operations specified below which allow Blocks to make use of the Information Routing Layer for such purposes, in addition to conventional message queuing, publishing and subscription facilities.
[0029] A Block makes information available for access by other Blocks in the integrated data network via the Information Routing Layer by providing specified information in the form of a Field in a Dataset. A Block may create a new Dataset or add a new Field to an existing Dataset. The Information Routing function applies a unique label to each new Dataset, and no other Block is able to use this label. Once such a label is generated, it is possible for the same Block to add another Field which can be attached to the same Dataset using the unique label as identifier.
[0030] At any one time, therefore, there is a finite set of Fields associated with any extant Dataset. It is not possible to add a Field to a Dataset if the new Field has the same Field Identifier as an existing Field in that Dataset. This is because the set of all Fields in any Dataset can not contain duplicate Field Identifiers (i.e. it must be a “Proper” set). The Information Router keeps track of existing Datasets.
[0031] A Block which requires particular information can attempt to obtain such information, if available from a source on the integrated data network, by raising a uniquely labelled “Information Request” including a Proper Set of Field Identifiers corresponding to the information being sought (the “Information Request Set”). The Information Request also includes an Attribute, identified as the “Information Request Value”, which can be used by the system to prioritise fulfilment of that Information Request. The “Information Request Value” may be allocated by the Block raising the Request or by the Information Router, or may be predetermined. Once a Request has been raised, it is held at the Information Routing Layer until fulfilment or expiry.
[0032] An Information Request is referred to as “Empty” until the specified Fields have been supplied via the Information Router. On submission of an Information Request, any existing Dataset that has the required Information Request Set may release a copy of that set of Fields via the Information Routing Layer.
[0033] The Information Router acts to ensure that regardless of how many existing Datasets may release the required Information Request Set, only one of these sets will be used to fulfil the Information Request. This operation is done in accordance with rules applied by the Information Router. Once an Information Request has been satisfied, the Fields in it can be made available to the Block that raised the Information Request via the Information Routing Layer. When this is done that Information Request is removed entirely from the system.
[0034] In addition to supplying or requesting information directly, a Block may have the capacity to process information and thereby be able to provide specified Output Information in exchange for particular Input Information.
[0035] If a Block has a capability to process information, it makes that capability known to other Blocks via the Information Routing Layer by raising a uniquely labelled “Exchange Set” which includes two Proper Sets of Field Identifiers (the “Input Set” and the “Output Set”). The union of the Input Set and the Output Set must itself be a Proper Set. The Exchange Set includes an Attribute known as the Exchange Cost. The Exchange Cost is used by the Information Router as a selection parameter to determine the priority to be given to completing a particular Exchange Set and/or to determining which Dataset(s) are selected to participate in a given Exchange Set transaction. The Dataset which supplies a specified Input Set will receive, in Exchange, the specified Output set.
[0036] Once an Exchange Set is created, any existing Dataset that holds the relevant Input Set may release a copy of that set of Fields via the Information Routing Layer. As for fulfilment of a direct Information Request, regardless of how many existing Datasets may be able to release the required Input Set, the Information Routing Layer ensures that only one of these will be used to supply the Exchange Set. The Information Router will only act to supply Input Sets to empty Exchange Sets. Additionally, the Information Router will not permit any supplying Dataset to include a Field which is specified in the Output Set of the Exchange Set. (Otherwise, if the Output Set includes a Field already in the Dataset, the result would not be a Proper Set.)
[0037] This supply of an Input Set is non-exclusive. For example, if a second Exchange Set exists with an identical Input Set, then a single existing Dataset holding that Input Set can satisfy both Exchange Sets. Again, because the supplying Dataset will receive the Output Set from both such Exchange Sets, it can only be permitted to supply both Input Sets if the union of the Output Set from each Exchange Set would be a Proper Set, that is, if there is no Field Identifier common to both Output Sets.
[0038] Once an Exchange Set holds the required Input Set, the Fields in it are made available to the Block that raised the Exchange Set. This same Block is then required to provide the specified Output Set of Fields into that Exchange Set. When the Exchange Set receives the Output Set, the Output Set Fields are attached to the original Dataset from which the Input Set was obtained and the Input Set Fields in the Exchange Set are emptied.
[0039] The net effect of this process is that the original supplying Dataset increases, or aggregates, its set of Fields via the addition of those in the Output Set. The Exchange Set then reverts to its original empty state. This means that the Exchange Set is once more made available for use by the Information Router. By following this process, the Information Router can selectively create aggregated Dataset(s) to meet Information Requests which cannot otherwise be met directly from an original Dataset.
[0040] [0040]FIG. 3 is a flow chart illustrating the basic steps taken by the Information Router in the process of aggregation by matching Datasets with Exchange Sets and Information Requests. When an Information Request (or data exchange) is accepted in step 100 , then the IRL decides whether an Aggregate Set can be formed in step 102 . If so, then the Aggregate Set is formed in step 104 . The combination of a Dataset, and a collection of zero or more Exchange Sets whose Output Sets form a Proper Set matching at least one Information Request is referred to as an Aggregate Set. The Information Router may use any appropriate selection technique to form such a combination. For example, any appropriate known search algorithm may be used to identify the optimal original Dataset which when combined with zero or more Exchange Sets will form an Aggregate Set satisfying one or more Information Requests. The appropriate Fields are delivered to blocks in step 106 . Finally, the status of all datasets is updated in step 108 .
[0041] [0041]FIG. 4 is a flow chart of the principal process steps for producing an Aggregate Set from a Dataset and using one or more Exchange Set to meet a specified Information Request. Step 200 evaluates whether there is an outstanding Information Request which has not been met by an Aggregate Set. If so, then the IRL reviews its store of Datasets in step 202 to see if one meets the Request but has not supplied the requested set of Fields. If so, then the IRL causes the Aggregate Set to be formed in step 204 and delivered as above. If not, then the IRL further evaluates in step 206 whether a Dataset could be subjected to a series of Exchanges in order the meet the Request. If so, then the IRL causes the appropriate Exchanges to be executed in order to form the Aggregate in step 208 .
[0042] The Information Router may cause many Aggregate Sets to form simultaneously in the Information Routing Layer within a District.
[0043] The Information Router uses the specified Information Request Value and Exchange Set Cost(s) to determine whether a particular Request can or should be fulfilled appropriately by possible Exchanges. The Information Request Value and Exchange Set Cost(s) may be representative of monetary costs or other measures of a critical resource, such as processor time or memory utilisation, which are relevant X 0 limiting factors in most circumstances. The Information Router uses these parameters (Attributes) to make operational decisions whether or not an Information Request can be met effectively within the applicable resource constraints.
[0044] Basically, the determining factor is that the total Exchange Set Costs in creating an Aggregate Set should not exceed the total Information Request Value(s) of the Information Request(s) which can be met by corresponding Aggregate Sets.
[0045] The sum of the Exchange Set Costs required to enable any given Dataset to satisfy any given Information Request is referred to as the Aggregate Cost. If the Aggregate Cost of a possible aggregation of Exchanges (“Exchange Route”) is greater than the Information Request Value, then that Exchange Route can be discarded as ineligible. If the Aggregate Cost for one Dataset is lower than that for a different Dataset, then the one Dataset will be preferred by the Information Router as the starting point for a Aggregate Set. If one Aggregate Set satisfies several different Information Requests, then that Aggregate Set will be preferred by the Information Router rather than having two or more separate Aggregate Sets satisfy those Information Requests, provided the Aggregate Cost of the one is less than the sum of the separate Aggregate Sets.
[0046] If one Aggregate Set can satisfy one of several Information Requests with identical Information Request Sets, then the Information Router can prioritise on the basis of maximising the margin between Value and Costs and act to satisfy first the Information Request whose Information Request Value less the corresponding Aggregate Cost is greatest.
[0047] In the present example, the Values and Costs have been treated as Attributes of the Information Request and Exchange Sets respectively. It will be apparent that the respective “values” or “costs” of fulfilling an Information Request could be predetermined or otherwise set by or for the Information Router, so that the Information Router might alternatively operate either by comparing an “Information Request Value” against (pre-)set costs or by comparing “Exchange Set Costs” against (pre-)set values.
[0048] The Information Router is able to maintain a history of the elapsed time between the Input Set of a Exchange Set being collected, and the Output Set of the Exchange Set being produced. If one Block historically completes its associated Exchange Set more quickly than another, then this Exchange Set may be preferred by the Information Router over another Exchange Set (or Sets) which could be aggregated to meet a particular Information Request.
[0049] The Information Routing Layer can impose a lifetime on Datasets, which may differ from District to District. For example, in a District supporting, say, a Computer Telephony system, a lifetime of a few minutes may be appropriate, whereas in a District dealing with historical customer records, a lifetime may be just that. Any Dataset older than its appropriate lifetime is “Expired”. An Expired Dataset will no longer be available from the Information Routing Layer.
[0050] Any Dataset which has supplied all possible Proper subsets of the Fields attached to the Dataset is deemed “Expended”. For example, a Dataset holding just one Field is expended as soon as that Field satisfies an Information Request. An Expended Dataset is removed entirely from the Information Routing Layer. It follows that any other Information Request requiring the same Information Request Set can only have its request satisfied by another Dataset, if at all, and that any one Dataset (not being part of an active Aggregate Set) may satisfy not more than N(N+1)/2 Information Requests, where ‘N’ is the number of Fields in the Dataset. No Dataset can be Expired or Expended if it is part of an extant Aggregate Set.
[0051] A Block that has raised any Dataset, Information Request or Exchange Set can shatter it at any time by invoking a “Shatter” operation using the Dataset's unique label. This may be done, for example, if the originating Block determines that the Dataset, Information Request or Exchange Set has been superseded or that one or more Fields are no longer valid. A Shattered Dataset, Information Request or Exchange Set will no longer be available from the Information Routing Layer.
[0052] If a Block that has raised an Information Request or an Exchange Set becomes disconnected from the Information Routing Layer for any reason, the Information Router may remove the consequent “Orphaned” Information Requests and Exchange Sets raised by that Block from the system regardless of the status of any Aggregate Sets comprising the relevant Exchange Sets or created to meet the relevant Information Requests.
[0053] An application of the present invention in the practical situation of a miniature a 1 t “call centre” with two staff will now be described with reference to FIGS. 5 - 8 to demonstrate how the Information Routing functionality can bring three major advantages to a common integration problem faced by many organisations: (i) rapid, cheap “proof of concept” of an overall solution using simulation; (ii) development of separated Blocks of functionality that neither communicate directly nor participate in a workflow that each Block (and therefore its programming team) needs to be aware of; and (iii) the ability to add new business functionality without in any way changing or impacting on existing Blocks.
[0054] [0054]FIG. 5 is a block diagram of a single “District” 41 comprising four Blocks 43 , 44 , 45 , 46 , functionally overlying an Information Router/information Routing Layer 42 . Block 43 is a Telephony Switch—this is the hardware into which the outside telephone lines are connected and to which all the call centre staff (“Agents”) are connected via a telephone handset in the usual manner. Block 44 is the Customer Database—this is the records system, which is able to look up and output customer details upon being given the telephone number from which the caller is ringing (using “CLI” or Caller Line Identification). Blocks 45 and 46 are Two Agent workstations—these are the PCs or terminals (separate from the telephone handsets) in front of which the Agents are seated.
[0055] In the Information Routing Layer 42 , three Exchange Sets 47 have been raised, one each by the Customer Database and the two Agent PC applications. These Exchange Sets are indicative of the information processing capabilities of the respective Blocks. As yet, no Datasets exist in the Information Routing Layer, nor any Information Requests.
[0056] [0056]FIG. 6 shows diagrammatically the changes which occur when a call arrives at the Telephony Switch 43 . The Telephony Switch 43 knows both the inward number dialled and the number from which the call originated (using Calling Line Identification 15 CLI) and is able to create a new Dataset 48 initially comprising two Fields, having Field Identifiers “PC 1 ” and “CLI” respectively, in the Information Routing Layer 42 .
[0057] In conjunction with the creation of this Dataset 48 , the Telephony Switch 43 also raises an Information Request 49 with a corresponding Information Request Set comprising the Field Identifiers “PC 1 ” and “Done”. This is essentially a request for confirmation that the new incoming call has been dealt with. Initially, this Information Request 49 cannot be satisfied, because no Dataset exists with both a “PC 1 ” Field and a “Done” Field. However, once the Request 49 has been submitted and is pending response in the Information Routing Layer 42 , the Telephony Switch 43 has no need to wait until a response is received, but is immediately freed to handle another incoming call should one arrive.
[0058] There are then five Information Sets of various forms available for interaction via the Information Routing Layer. FIG. 7 illustrates how the Information Router handles these Sets. Firstly, the Information Router 42 determines that the Information Request 49 raised by the Telephony Switch 43 can be satisfied if the Dataset 48 originally raised by the same Block 43 is matched up with two of the Exchange Sets 47 —one which delivers the “Details” Field as its Output Set (from the Database 44 ) and another one which delivers the “Done” Field as its Output Set (e.g. from Agent PC 1 , Block 45 ).
[0059] The origins of the various Sets are unimportant as far as the Information Router is concerned. Its objective is simply to find an effective aggregation to meet any pending Information Request. In the case shown in FIG. 7, the Information Router 42 has chosen to aggregate two Exchange Sets 47 and the Dataset 48 with the Request 49 forming an Aggregate Set 50 .
[0060] The Information Router proceeds with the following steps:
[0061] (i) the “CLI” Field is sent to the Customer Database 44 , which responds with the customer “Details” Field which is then attached to the relevant Exchange Set 47 . p 1 (ii) as this Field makes up the entire Output Set in that Exchange Set, the Information Router 42 moves the Output Set into the Dataset 48 and the Input Set is cleared from that Exchange Set 47 , leaving it empty once more. This means that the Customer Database 44 is immediately able to provide another set of “Details” for exchange when the next call arrives.
[0062] (iii) the “PC 1 ”, “Details” and “CLI” Fields are now available from the Dataset 48 for the Agent PC 1 .
[0063] (iv) The Agent PCl (Block 45 ) now has all the information required properly to conduct the call with the customer. The Agent PCl can take as long as it likes to raise the “Done” Field once it is in receipt of its specified Input Set [PC 1 ,CLI, Details]—this corresponds to the Agent's telephone conversation taking as long as necessary.
[0064] (v) When the call finishes, the Agent PC 1 enters the “Done” Field into its Exchange Set 47 .
[0065] (vi) Since this Field makes up the entire Output Set, the Information Router 42 transfers the Output Set into the Dataset 48 and the Input Set information is cleared from the Exchange Set, leaving it Empty once more. This means that the Agent PCl is immediately able to take and complete a new call using its Exchange Set to record the relevant information.
[0066] (vii) The “PC 1 ” and “Done” Fields are now available to satisfy the Information Request 49 originally raised by the Telephony Switch 43 .
[0067] (viii) Upon receipt of that satisfied Information Request 49 , the Telephony Switch 43 is able to close down the call to Agent PC 1 . The satisfied Information Request 49 , having been delivered to the Block 43 that raised it, is also removed entirely from the Information Routing Layer 42 .
[0068] The Information Router 42 has now done its work and, as illustrated in FIG. 8, the Information Routing Layer contains the original Exchange Sets in the same Empty state as in Stage 1 (FIG. 5) with the addition of a Dataset 48 , which has supplied an Information Request Set comprising the “PC 1 ” Field and the “Done” Field. This Dataset 48 is not permitted to supply a further Information Request Set with the information in any Field already supplied in response to an identical, previous Information Request 49 , so the continued availability of this Dataset 48 for other potential uses does not impact the handling of future calls. It may be that the Dataset 48 will expire (if this option is enabled within the Information Router 42 ).
[0069] It is important to note that at no time is the order of operations (or “workflow”) specified, nor is it necessary to program for specific interactions between Blocks in the integrated data network. The Information Router 42 simply takes the information available from the various independent Blocks and allocates or distributes that information to meet Information Requests from a Block. In a real-life environment (such as a call centre with hundreds of lines), using current processing technology, the Information Router can readily process multiple Information Requests and perform many aggregations simultaneously. No Block itself need even be aware of the existence of any other particular Block. This is a significant advantage of the present invention, which enhances system flexibility.
[0070] This flexibility is demonstrated in the example illustrated in FIGS. 9 and 10, which illustrate how the District 41 from the previous example can bear the addition of a new Call Logging Facility 51 without any changes whatever to the existing Blocks. This provides considerable potential for savings in the time and cost of implementation over existing methods and systems.
[0071] In FIG. 9 a new Block 51 , a Call Logger, has been added to log completed calls. It makes this function known to the Information Router 42 by raising an Information Request 52 requesting the “CLI” Field and the “Done” Field. Whenever this Information Request 52 is satisfied and the requested information is delivered by the Information Routing Layer 42 to the Call Logger 51 , it stores the information in its Call Log database and will then raise a new Information Request. In the present example, as shown in FIG. 10, the Information Router 42 recognises that the initial Information Request 52 from the Call Logger 51 can be met by supplying the “CLI” and “Done” Fields from the currently available Dataset 48 , which has not previously been used in response to such an Information Request.
[0072] The Call Logger 51 can therefore operate at its own rate, fast or slow, without affecting its ability to log all the calls that occur - this is because even if new Datasets with new “CLI” and “Done” Fields are raised faster than the Call Logger 51 can gather the relevant information with new Information Requests, the Information Routing Layer 42 will simply deliver that information from each new Dataset as and when a new Information Request is raised.
[0073] It will be apparent that the Information Routing Layer according to the present invention may be implemented by distributed components of hardware and software or by a single device depending upon suitability for any particular application. The Fields, Attributes and supplied sets associated with a Dataset may therefore be held within a single device or distributed amongst more than one. This applies also to the storage and processing associated with Information Requests and Exchange Sets.
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The invention is an improved method and apparatus for information routing and sharing in multiple computer networks, which can facilitate automatic integration of diverse network and data systems. In an integrated data network comprising multiple computer systems, distinct information users and sources may each be considered as a block. An information routing layer coupled to each of the blocks provides for the routing of information provided in the form of datasets, which are combinations of field names, types, values and other components. An existing dataset can be provided or an aggregate set can be constructed as required to meet an information request from a block in the integrated data network without programmatic or specified workflow reference to other blocks.
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TECHNICAL FIELD
[0001] This invention relates to fibrous catalyst-immobilization systems and methods for their synthesis and use.
BACKGROUND OF THE INVENTION
[0002] Chemical production processes generally employ fluid flow as a means for introducing chemical reactants to relatively fixed catalyst pellets. But these catalyst pellets fracture into particles, which deleteriously impacts processing efficiency.
[0003] Not only can these particles damage processing equipment and interfere with reaction products, but ordinary environmental regulations require that they be filtered out of a processing fluid prior to discharge into the environment. Moreover, fractured catalyst pellets must be replaced. Therefore, a method for preventing catalyst pellets from fracturing would significantly improve the efficiency of chemical production processes.
[0004] Another problem relates to the transport rates of reactants and reaction products to and from a catalyst pellet's catalytic reaction cites. Generally, chemical reactants reach a catalyst pellet's inner-surface area by traveling through the pellets' pores. However, as the size of a pellet increases, the length of its pores increases proportionally. And relatively large catalyst pellets can have pore lengths so great that all of their catalytic reaction sites are not utilized by the reactants. This problem stems from the prior art's methods that employ porous catalyst pellets having characteristic dimensions ranging from a few microns to a few millimeters.
SUMMARY OF THE INVENTION
[0005] The present invention provides a fibrous catalyst-immobilization system composition comprising a fiber and a catalyst encapsulated within the fiber.
[0006] The present invention also provides a method for securing the relative positions of catalysts that are subject to fluid flow comprising the steps of providing a fibrous catalyst-immobilization system, securing the system to a structure that is not displaced as a result of the fluid flow, and subjecting the system to the fluid flow.
[0007] The present invention also provides a method for preparing fibrous catalyst-immobilization systems comprising the steps of providing a solution comprising both a fiber-forming material and a catalyst, and processing the solution into at least one fiber.
[0008] Fibrous catalyst-immobilization systems (fibrous systems) advantageously overcome problems in the prior art by protecting a catalyst pellet from fracture while securing its relative position within a production process employing fluid flow. Transport limitations are also overcome because the fibrous systems can employ relatively smaller catalysts than those catalysts employed in the prior art. Fibrous systems provide an additional advantage in that the thickness of the fiber surrounding a catalyst is relatively thin, which allows reactants to diffuse in and out of the fibrous systems in a relatively short times.
[0009] The term “pellet” refers to a solid substance, e.g., porous substance or monolith, that can be granular, sheet-like, or needle-like that also has a characteristic dimension as small as about two nanometers.
[0010] The term “characteristic dimension” refers to a measurable length that is a primary means for describing a catalytic substance. For instance, where a solid catalytic substance is granular, a characteristic dimension is its diameter; where a solid catalytic substance is rod-like, its characteristic dimensions are diameter and length; where a solid catalytic substance is sheet-like, its characteristic dimensions are its thickness, length, and width.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1A is a scanning-electron-microscope image of a fibrous catalyst-immobilization system comprising the polymeric fiber-forming materials polycaprolactone and poly(ethyloxazoline) (PEOz) wherein a pollen particle is positioned within the fibrous system. In this figure, one inch is the scale equivalent of 10 microns.
[0012] [0012]FIG. 1B is a scanning-electron-microscope image of the fibrous system as presented in FIG. 1A after PEOz was dissolved from the fibrous system with water. Removing the PEOz revealed portions of the surface of the pollen particle. In this figure, one inch is the scale equivalent of 10 microns.
[0013] [0013]FIG. 2A is a scanning-electron-microscope image of a fibrous catalyst-immobilization system wherein a zinc oxide catalyst is positioned within a polycaprilactone fiber. In this figure, approximately 0.5 centimeters is the scale equivalent of 1 micron.
[0014] [0014]FIG. 2B is a transmission-electron-microscope image of a fibrous catalyst-immobilization system comprising a polycaprolactone fiber and a zinc oxide catalyst positioned therein. In this figure, approximately 1.5 cm is the scale equivalent of 200 nanometers.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Fibrous catalyst-immobilization systems comprise a fiber and at least one catalyst encapsulated within the fiber. The term “encapsulate” refers to the positioning of a catalyst within a fiber. A catalyst is encapsulated within a fiber when it is tethered within a fiber such that none or part of the catalyst's surface area is exposed. FIGS. 1A, 1B, 2 A, and 2 B provide illustrative examples of fibrous systems.
[0016] Catalysts are substances that either accelerate or retard the rates of chemical reactions without being permanently affected thereby. Catalysts can be inorganic, organic, or mixtures thereof; they can exist in any physical solid state and as single molecules. Solid catalysts are generally produced commercially as both porous substances and monoliths. Monolithic catalysts lack pores and therefore only their outer surface areas can present catalytic reaction sites to reactants. Porous substances, on the other hand, tend to maximize their surface area per unit mass and therefore have far greater surface area per unit of mass than monoliths. Molecular catalysts can provide even greater surface areas per unit mass than porous solids.
[0017] Any catalyst can be employed in the fibrous systems, and persons having ordinary skill in the art can select useful catalysts without undue experimentation. Nonlimiting examples of catalysts that can be employed include zeolites, aluminum silicates, metals, and metal-containing compounds.
[0018] Catalysts can be employed in fibrous systems wherein the catalysts have characteristic dimensions ranging from the molecular level up to solids having characteristic dimensions of about 2 millimeters. Preferably a characteristic deminsion of a solid catalyst is at least about two nanometers. More preferably, catalysts having characteristic dimensions ranging from about 5 nanometers to about 1 millimeter are employed. Still more preferably, catalysts having characteristic dimensions ranging from about 100 nanometers to about 100 microns are employed.
[0019] The catalyst loading of a fibrous catalyst-immobilization system can make up from about 0.01% to about 99% weight of the fibrous system. Preferably catalytic loading makes up from about 0.1% to about 10% weight of the fibrous system, and more preferably catalytic loading makes up from about 1% to about 10% weight of the fibrous system.
[0020] Fibers employed in the present invention can comprise a variety of fiber-forming materials, which include any polymer that can be dissolved in a solvent. Preferably, a polymer that retains its mechanical strength while swollen within solvents, reactants, or reaction products is employed because of its durability under conventional chemical process operating conditions. More preferably, polymeric fiber-forming materials are employed in synthesizing fibers that can be crosslinked into a strong network after they are processed into a fiber. Examples of useful fiber-forming materials include, but are not limited to, polymers such as nylon, polyacrylonitrile (PAN), polyesters, polyurethanes, silanes, or copolymers thereof.
[0021] The percent concentration of fiber-forming material in a fibrous catalyst-immobilization system can make up from about 1% to about 99% weight of the system. Preferably fiber-forming material makes up from about 20% to about 80% weight of the system. More preferably, fiber-forming material makes up from about 40% to about 75% weight of the system.
[0022] Useful fibers have a diameter ranging from about 1 nanometer to about 25 microns. Preferably, the fibers have a diameter ranging from about 2 nanometers to about 2 microns. More preferably, the fibers have a diameter ranging from about 1 nanometer to about 1 micron, and still more preferably from about 1 nanometer to about 500 nanometers.
[0023] The fibrous catalyst immobilization systems are made up, in part, of a fiber-forming material. In a preferred embodiment, two or more distinct polymers are employed as fiber-forming materials in fibrous catalyst-immobilization systems, and solubility differences preferably exist between the polymers employed. Solubility differences between the polymeric fiber-forming materials allow them to be selectively removed from a fibrous catalyst-immobilization system by dissolving them with a selected solvent. After using a selected solvent to dissolve one of the polymers, the remaining insoluble polymer(s) continue to encapsulate the catalysts while more of the catalytic surface area, which has been revealed by dissolving the soluble polymer, is exposed and therefore made available to reactants. FIGS. 1A and 1B are an illustration of a fibrous system comprising fiber-forming materials that have solubility differences. As a result, reactants and reaction products can diffuse more readily into and away from the catalyst. Further, the structure of the fibrous systems preferably allows processing fluids to flow through them at a relatively high rate. Preferably, poly(ethyloxazoline) (PEOz) and polycaprolactone are polymeric fiber-forming materials that are employed together in fibrous systems because of their solubility differences.
[0024] Where two distinct polymeric fiber-forming materials are employed in the fibrous system, the ratio of one polymer type to another can range from about 100:1 to about 1:1 by weight. Preferably the ratio ranges from about 75:1 to about 1:1 by weight, and more preferably the ratio ranges from about 50:1 to about 1:1 by weight.
[0025] Fibrous catalyst-immobilization systems can be employed in a variety of manners. They may be used by themselves to form a porous membrane, which can be constructed in cylindrical geometry. They can also be used in coordination with a support system such as a porous substrate or solid surface. Even further, they can be woven into a skeletal support matrix comprising other types of fibers.
[0026] When used by themselves, fibrous catalyst-immobilization systems can be woven together to form a porous membrane having many fibrous systems per unit area. In production processes, this membrane can be used with or without a support structure. While the membrane is being used in a production process, the fluid can flow either parallel or perpendicular to the membrane's surface. The reactants that are in the passing fluid can move through the membrane either by diffusion, osmotic pressure, or pressure drop. While moving through the membrane, the catalysts encapsulated within the fibers are exposed to the reactants and reaction products result.
[0027] A porous structure can be used to support layers of the fibrous systems within a chemical production process. The porous support structure is preferably designed with a low concentration of fibrous systems arranged in layers that are stacked and positioned perpendicular to the direction of fluid flow; each of these layers preferably having relatively few fibrous systems per unit area. The layers of fibrous systems preferably have spacing between them that gives depth to the stacked layers. And because each of the layers preferably has a low concentration of fibrous systems per unit area, enough of the layers are preferably stacked on top of each other to provide all of the passing reactants with a sufficient number of catalytic reaction sites. As the spacing between each of the stacked layers increases, the pressure required for the fluid to flow through the layers decreases. The pressure required for fluid to flow through a porous support structure with many stacked layers is less than the pressure required for the fluid to flow through a single membrane having a relatively dense concentration of fibers.
[0028] Various conventional techniques that can be used to form fibers can be employed in synthesizing fibrous catalyst-immobilization systems, however electrospinning is preferred. The technique of electrospinning of solutions containing fiber-forming material is known and has been described in a number of patents and general literature. Electrospinning involves introducing a solution into an electric field, whereby the solution is caused to produce fibers that tend to be drawn to an electrode. While being drawn from the solution, the fibers usually harden, which may involve cooling (e.g. where the liquid is normally solid at room temperature), chemical hardening (e.g. by treatment with a hardening vapor), or evaporation of solvent (e.g. by dehydration). The product fibers may be collected on a suitably located receiver and subsequently stripped from it. Electrospinning can produce fibers from a great variety of fiber-forming materials, and the fibers can have diameters greater than or equal to about two nanometers.
[0029] When electrospinning is employed, any solvent in which a fiber-forming material is soluble can be used to prepare solutions that can be used to synthesize fibrous systems. Therefore, when preparing solutions comprising fiber-forming materials and catalyst pellets, persons of ordinary skill in the art can select appropriate solvents based on the solubility characteristics of the fiber-forming material(s) without undue experimentation.
[0030] In preparing a solution to be used in forming fibrous systems, acetone is preferably employed as a common solvent where the solution comprises both PEOz and polycaprolactone as the fiber-forming material; water is preferrably employed as the solvent for selectively dissolving PEOz from the fiber.
[0031] Catalysts are preferably encapsulated within a fiber by adding them to a solution that is to be electrospun into a fiber. Upon electrospinning, the catalysts become encapsulated within the fiber.
[0032] Where a catalyst is soluble in a solution comprising fiber-forming material and electrospinning is employed in preparing a fibrous catalyst-immobilization system, fibrous systems typically result that comprise molecular catalysts. This occurs because the electrospinning process removes the solvent instantly and therefore prevents any soluble catalytic substance from crystalizing into a solid.
[0033] When synthesizing fibrous catalyst-immobilization systems using electrospinning techniques, soluble catalysts can be employed in a solution to be electrospun from about 0 to about 50 percent volume of the solution. Preferably soluble catalysts are employed from about 0 to about 30 percent volume of the solution. More preferably, soluble catalysts are employed from about 0 to about 15 percent volume of the solution.
[0034] When synthesizing fibrous catalyst-immobilization systems using electrospinning techniques, catalyst pellets can be employed in a solution to be electrospun from about 0 to about 25 percent volume of the solution. Preferably catalyst pellets are employed from about 0 to about 20 percent volume of the solution. More preferably, pellets are employed from about 0 to about 15 percent volume of the solution.
[0035] Where electrospinning is employed in synthesizing a fibrous system, the percent concentration of fiber-forming material in a solution for electrospinning can be from about 0 to about 25 percent volume of the solution. Preferably fiber-forming material is employed from about 0 to about 20 percent volume of the solution. More preferably, fiber-forming material is employed from about 0 to about 15 percent volume of the solution.
[0036] The percent concentration of a solvent in a solution for electrospinning can be from about 0 to about 99 percent volume of the solution. Preferably solvent is employed from about 0 to about 85 percent volume of the solution. More preferably, solvent is employed from about 0 to about 75 percent volume of the solution.
[0037] In order to demonstrate the practice of the present invention, the following examples have been prepared and tested. The examples should not, however, be viewed as limiting the scope of the invention. The claims will serve to define the invention.
EXAMPLES
[0038] Table I presents the composition and % volume of a solution that was electrospun into a fibrous catalyst-immobilization system.
TABLE I Component % Volume of the Solution Solvent = formic acid 80-85 Fiber-forming material = nylon 15-20 Catalyst = aluminum fibers 1-2
[0039] The aluminum fibers are about two nanometers in diameter and 1 to 2 microns long. The aluminum fibers were made in a separate process and were added to the solution without modification.
[0040] While the best mode and preferred embodiment of the invention have been set forth in accord with the Patent Statues, the scope of this invention is not limited thereto, but rather is defined by the attached claims. Thus, the scope of the invention includes all modifications and variations that may fall within the scope of the claims.
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The present invention provides a fibrous catalyst-immobilization system that can be employed for immobilizing catalysts that are subject to fluid flow within a chemical production process. The fibrous systems can be synthesized using electrospinning and the catalysts are secured in the fibers during the electrospinning process.
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THE FIELD OF THE INVENTION
The field of invention is refrigeration system servicing, and more particularly a detector tube assay employing a solvatochromic indicator for use in refrigeration system servicing.
BACKGROUND OF THE INVENTION
Refrigeration fluids are split into two phases, first the refrigerant phase, which is typically a low boiling point fluorocarbon gas, liquid or vapor, and secondly the oil phase, which can be either a mineral, alkylbenzene, polyol ester or polyalkylene glycol lubricant. Applicant is the inventor of a refrigerant gas contamination detector kit shown in U.S. Pat. No. 5,419,177. The specification of this '177 patent is incorporated by reference herein.
The '177 patent relates to detector tube analysis of contaminants in a refrigerant gas under pressure. The present invention specifies a detector tube for determining the level of contaminates that are present in the oil phase.
In general, both phases will exhibit some degree of contamination in the form of water since it is nearly impossible to purify or render the fluids fully anhydrous. Although not desirable, water is always incidental and inherently present. Water levels that exceed 10 ppm as measured in the refrigerant phase or water levels that exceed 50 ppm as measured in the oil phase can undergo hydrolysis to form detrimental acids when subjected to the heat and compression of refrigeration equipment cycling. Typically a high moisture content will promote inorganic acids to form out of the refrigerant and organic acids to form out of the lubricants over the working life of the refrigeration system. Neglect and the lack of preventative maintenance in the detection of high moisture and acid formation are conditions that can lead to premature compressor or other associated refrigeration component failures.
Obtaining an oil sample for testing can be very labor intense. For example, the service technician must remove anywhere from 1 to 50 milliliters of oil from a compressor crankcase of a sealed system. Since most all compressors of the hermetic variety have no oil tap or drain plug, the equipment must be taken off line and opened. This involves the removal and recovery of the pressurized refrigerant gas in the system, removal and inversion of the compressor to pour out an oil sample for testing; then reinstallation of the compressor, complete evacuation of the system and finally recharging with refrigerant gas for eventual equipment start-up and on-line duty.
Laboratory sample submission for quantitative acid and/or moisture analysis is generally too impractical for the average service technician versus the availability of an instant on-site test.
PRIOR ART
Traditionally, field test methods for determining the acid content of the oil phase of a refrigeration system is limited to pH indicators. Typically, the test kit contains a pH dye such as Bromophenol Blue or other pH indicating solutions or strips. The problems with the use of pH indicators in refrigeration diagnostics are bountiful, in that, (1) the pH range of indicator dyes are too broad, (2) a definitive end point (color change) may be masked or buffered by certain oil additives, (3) the oil type being tested may exhibit solubility problems with the test solution or strip, (4) moisture levels are not indicated, and (5) pH dyes are more reliable with aqueous media than with organic solvents.
With the advent of solvatochromic chemistry, a more accurate and reliable field test for oil contamination is possible. However, the solvatochromic dyes of the Pyridium-N-Phenol Betaines, described in U.S. Pat. Nos. 4,677,076, 4,677,079 and 4,722,983 failed due to their lack of distinct or discernable color differentiation in the visible range when small shifts in solution polarity must be quantified. The Pyridium-N-Phenol Betaines along with the classic solvatochromics of the Indoanilines, Carbonylpyridiums and Nitroanilines all require the use of sensitive colorimetric instruments to measure differences in color intensity.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a more definitive oil phase test which will be easy to use in the field and provide better quantitative results relative to the degree of contaminants therein. The oil phase test is preferred but not limited to a detector tube assay being of the same construction and/or adaptability to the detector tube holding device described in U.S. Pat. No. 5,419,177 which is incorporated herein by reference.
The specification for an indicator material shall be formulated with a dye or dye combination of the solvatochromic Benzophenoxazine - Benzophenoxazone compounds.
This invention in particular relates to compounds and/or materials that will exhibit color transitions or separations when small shifts in the polarity of a solvent must be determined. Specifically, but not limited to, refrigeration compressor oil that becomes more polar due to moisture, acid, dissolved metals or other aggressive polar adulterants.
DETAILED DESCRIPTION OF THE INVENTION
Solvatochromism is expected when the oil polarity has undergone change. Assume that a virgin anhydrous oil or nearly anhydrous oil represents the ground state; then a more excited state can be induced by the addition of adulterants such as water, acid, base and/or other aggressive ionic materials.
A small group of dyes are known to undergo color transition with changes in solution polarity and these dyes may be tailored to act as a probe. Ideally, the probe will be sensitive enough to promote a definite, distinguishable color transition from the ground state, stepwise to higher polar states. The color transitions specific for this invention must be readily identifiable in the visual range since the average service technician is not familiar with the application and use of colorimetric instrumentation.
The best suited solvatochromic dyes for this invention were determined by exhaustive chemical screening. It was discovered that the best dye candidates belong to the Benzophenoxazine and/or Benzophenoxazone families having the basis structure: ##STR1##
When X is an amine, alkyl amine or dialkylamine group and R is an alkyl amine or dialkylamine containing 1-10 carbon atoms, derivatives of the Benzophenoxazine family are represented. ##STR2##
When X is an oxygen and R is alkylamine or dialkylamine containing 1-10 carbon atoms, derivatives of the Benzophenoxazone group are represented.
The Benzophenoxazines are typically prepared by reacting 5-diethyl amino-2 nitrosophenol with 1-naphthylamine. The Benzophenoxazones are formed by refluxing the Benzophenoxazine with sulfuric acid.
The oxazine compounds can be treated with a hydroxide, chloride or sulfonated to form radical salts. ##STR3## y=1 when treated with a Chloride or Hydroxide y=2 when Sulfonated
The radical salts offer similar degrees of solvatochromism, but can exhibit different degrees of solubility with the target solvents. A salt must be chosen that will dissolve in the target solvent/solvents in order for a solvatochromic effect to occur. A radical salt of the Benzophenoxazine can be tailored to exhibit more or less solubility characteristics for the target solvent. The ratio of Benzophenoxazine to Benzophenoxazone may be adjusted to limit or broaden the solvatochromic property's range or effect.
Experimentally then, each oxazine and oxazone dye can be dissolved in various organic oils or solvents. Coloration of the oil or solvent will vary based on the minute' differences in polarity. For example, a purified non-polar solvent represents a ground state and would exhibit a light coloration, while a more polar solvent representing a more excited state would exhibit a darker color.
In practice, the lubricants listed below are the most conventional and predominate oils used in the refrigeration industry to date:
Mineral Oil (MO)
Alkylbenzene (AB)
Polyol Ester (POE)
Polyalkylene Glycol (PAG)
Virgin samples of the above oils were obtained and allowed to dry for one week over anhydrous silica gel, then passed through a column containing Brockman I activated alumina. The results from Karl Fischer titrations on the dried solvents indicated that the water content of the liquids did not exceed 5 ppm. The oils now represent a near ground state. Alloquats from each oil were then adulterated with the addition of various amounts of water, acid and combinations of water and acid that would typically be found in operating refrigeration compressors and thereby represent different excited states. It should be noted that the acidic component was a 50/50 mixture of hydrochloric and oleic acids which are the two most predominate acids of formation within a refrigeration system.
The solvatochromic oxazine and oxazone dyes of the radical hydroxide form were allowed to dissolve, in each near ground state oil respectively, and the color change noted:
GROUND STATE OIL TEST
______________________________________GROUND STATE OIL TESTWith Oxazine Oxazone Oxazine + Oxazone______________________________________MO no color pale yellow bright yellowAB pale yellow yellow yellow/brownPOE yellow/orange orange orangePAG orange orange pink______________________________________
The natural order of polarity of these solvents are ascending, being that MO is nonpolar, AB is slightly polar, POE is moderately polar and PAG is the most polar solvent. A definite solvatochromic shift is confirmed with the dyes and dye combinations by the distinctive color transition from no color to yellow to orange to a weak red (pinkish).
An extensive study was conducted to determine which individual dye or dye combination would give the best color resolution as well as a definitive stepwise color transition with adulterated oils. All the trial and error data revealed that a combination of oxazine and oxazone were far superior for color differentiation when each isolated dye or dye derivative was tested.
The optimum dye mixture was mainly composed of the radical hydroxide oxazine with a counter balance of from 0.001 to 0.010% oxazone, where about 0.005% oxazone is preferred.
The test observations when 0.04 grams of the optimized solvatochromic dye is dissolved in 100 grams of the adulterated oils below.
CONTAMINATED OIL TEST
__________________________________________________________________________CONTAMINATED OIL TEST 25 ppm 40 ppm 50 ppm 90 ppm 150 ppm water water water water water25 ppm 40 ppm 90 ppm 10 ppm 25 ppm 25 ppm 50 ppm 100 ppmwater water water acid acid acid acid acid__________________________________________________________________________MO yel org mag pink lav mag vio blueAB yel org mag pink lav mag vio bluePOE org pink mag pink lav mag vio bluePAG org pink mag pink lav mag vlo blue__________________________________________________________________________
It can be concluded that a nearly quantitative solvatochromic shift, yellow to orange to pink to lavender to magenta to violet to blue, is established. A subjective evaluation is forwarded being that a color less than magenta being yellow, orange, pink or lavender would indicate that an acceptable amount of water-acid contamination is present in the bulk lubricating oil, and any color intensity magenta or greater being magenta, violet or blue would indicate a highly polar and adverse condition within the bulk lubricant. The criteria for the pass/fail scenario is in alliance with the standards set forth by the refrigeration industry, where the threshold limit for water should not exceed 50 ppm and the sum of acid plus water be less than 70 ppm in totality.
It should be noted that it is the amount of oxazone a component (about 0.005%) added into the dominate oxazine dye formulation that balances the final color scheme. Addition of excess oxazone will cause greater red shifts while insufficient or when no oxazone is incorporated blue/violet shifts occur too prematurely with initially more polar POE and PAG solvents.
It is conceivable that an oil or solvent be charged with a solvatochromic dye or dye complex in order to monitor the condition of the oil or solvent over time. Such applications may be useful in determining when to change the oil or solvent in air compressors, vacuum pumps or other internally lubricated mechanisms. Or, if it is not desirable to charge the oil or solvent with dye, a small sample of oil could be externally tested with a strip or solution containing the dye.
A detector tube construction for sampling oil directly from a sealed refrigeration system is forwarded herein, since a detector tube assay offers an instant evaluation of the oil phase without disassembly or operating downtime.
Experimentally, 0.05 to 0.25% solution of the oxazine/oxazone dye was dissolved in anhydrous methanol, with 0.10% being preferred. The solution was coated onto an inert substrate such as powdered borosilicate glass and the alcohol and any associated water was evaporated off with heat in a dry box circulating dry nitrogen gas.
Into a 3.5" 1×5/32" diameter detector tube, a dry and sterile acrylic bating was compacted to a length of 1/2" assembled in the same dry box. About a 2" fill of the dye coated powdered glass was then packed above the acrylic batting. The detector tube ends were then sealed with rubber stoppers as to conform to the construction of a detector described under the previous patent.
The sealed detector tube was removed from the box and inserted into a detector tube holding device (see U.S. Pat. No. 5,419,177, FIGS. 2-7, and columns 2-4) that was connected to the suction (return line) service port of an operating refrigeration system. It is known that small amounts of oil will be carried with the circulating refrigerant gas, and by connection to the service port, refrigerant gas and trace amounts of oil will bleed through the detector tube. It should be noted that the amount of oil necessary to obtain a good test result could be as small as 10 microliters. A de minimis bleed for about 15 seconds caused trace amounts of oil to enter into the detector tube, flushed through the dye substrate and deposited an orange stain onto -the acrylic batting. The contaminant level of the oil was known prior to the test to contain 35 ppm water and less than 0.10 ppm acid. Thus, the result was consistent with laboratory trials from a representative sample.
Subsequent testing on many other refrigeration systems also yielded results that consistently correlated with the lab data. Experimentally, the dye a was coated onto a variety of other different substrates in attempts to find the most suitable substrate. Any substrate that had a polar character performed less satisfactorily than those that were non-polar or otherwise highly inert. Different fabric or stain enhancing materials were substituted for the acrylic batting. Sterile cellulose, cotton, wool and non-polar polymer fabrics worked satisfactorily with the natural fabrics being preferred due to their more permanent color fastness to a dye wash. Some ion exchange resins were also tested with satisfactory results.
The specific detector tube arrangement therefore consists of a solvatochromic dye of the Benzophenoxazine and/or Benzophenoxazone groups coated onto a substrate which is upflow from a stainable media, developer or indicating layer. Oil is allowed to enter the tube, come in contact with and wash through the dye segment and then stain a second segment. The resultant color which is retained by the second segment indicates the polarity of the oil being sampled. The endpoint color can then be visually matched to a color chart for a semi-quantitative analysis.
The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
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A process and apparatus for determining the amount of contamination in the lubricant phase of a refrigeration system. The process utilizes a clear glass tube which contains an inert substance such as glass beads coated with a solvatochromic compound, preferably the solvatochromic compound is a mixture of Benzophenoxazine and Benzophenoxazone. A sample of the lubricant to be tested is passed into the glass tube and passes over the glass beads, picking up a portion of the solvatochromic compound. A white absorbent material such as sterile cellulose is positioned adjacent the coated substrate and the color reaction between the lubricant and the solvatochromic compound is clearly evident on the white absorbent material which then can be compared with a standard set of colors to determine the amount of the contamination.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Chinese Patent Application No. 20061006310.5 filed on Oct., 07, 2006. The contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a steering control apparatus for a vehicle, and more particularly, to a steering wheel having force-cushioning elements.
[0004] 2. Description of the Related Art
[0005] In vehicle collisions, a major threat to the driver's life and safety comes from impacting the steering wheel. This is because conventional steering wheels are made of rigid materials, which while allowing for an easy rotation of the steering wheel about a supporting shaft, often impact with the driver's body at a great force when the driver collides with the steering wheel in a direction normal or substantially normal to the plane of the wheel. In such collisions, the wheel generally damages the driver's internal organs, which often carries fatal consequences.
SUMMARY OF THE INVENTION
[0006] In view of the above-described problems, it is one objective of the present invention to provide a steering wheel having force-cushioning elements so as to cushion a force impacting from a direction normal or substantially-normal to the plane of the steering wheel.
[0007] To achieve the above objective, in accordance with one embodiment of the present invention, provided is a steering wheel for a vehicle comprising a grip frame; one or more spoke frames; a supporting shaft; and at least one force-cushioning element; wherein the spokes connect the grip frame to the supporting shaft; the grip frame and/or the spoke frames comprise two or more frame parts; the force-cushioning element is disposed between the frame parts; and the force-cushioning element is capable of being deformed by a force exerted by a driver colliding with the steering wheel whereby deforming the grip frame and/or the spoke frames.
[0008] In certain classes of this embodiment, the cushioning element is capable of absorbing kinetic energy while being deformed by the force, the force being normal to a plane defined by the grip frame.
[0009] In certain classes of this embodiment, the grip frame comprises an upper grip frame portion and a lower grip frame portion, wherein at least one force-cushioning elements is disposed between the upper grip frame portion and the lower grip frame portion.
[0010] In certain classes of this embodiment, the spoke frame comprises an upper spoke frame portion and a lower spoke frame portion, wherein at least one force-cushioning elements is disposed between the upper spoke frame portion and the lower spoke frame portion.
[0011] In certain classes of this embodiment, the force-cushioning element is disposed between the spoke frame and the supporting shaft.
[0012] In certain classes of this embodiment, the force-cushioning element is selected from a group consisting of a flat plate, an L-shaped plate, and a plate having a tooth-shaped surface.
[0013] In accordance with another embodiments of the invention provided is a steering wheel for a vehicle comprising a grip frame; one or more spoke frames; a supporting shaft; and at least one force-cushioning element; wherein the spoke frames connect the grip frame to the supporting shaft; the grip frame is annularly-shaped and elastic, the spoke frames are elastic; and the grip frame and the spoke frames are rigid in a direction parallel to a plane defined by the grip frame, yet are also capable of being elastically-deformed by a force exerted by a driver colliding with the steering wheel whereby deforming the grip frame and/or the spoke frames.
[0014] In certain classes of this embodiment, the cushioning element is capable of absorbing kinetic energy while being deformed by the force, the force being normal to a plane defined by the grip frame.
[0015] In certain classes of this embodiment, the grip frame is an annularly-shaped flat plate and the spoke frame is an elastic plate.
[0016] The steering wheel of the present invention provides the following general advantages: (1) in the working direction such as the rotating direction of the steering wheel, the steering wheel is rigid so that the steering control to the vehicle is not influenced; and (2) in the event of a collision, e.g., a frontal collision, the steering wheel is impacted by the body of a driver, and correspondingly, is deformed forward by means of the force-cushioning element, thereby reducing or avoiding an injury to the driver.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a top plan structural view of a steering wheel in accordance with one embodiment of the invention;
[0018] FIG. 2 a is a perspective view of a force-cushioning element in accordance with one embodiment of the invention;
[0019] FIG. 2 b is a side view of a force-cushioning element of a steering wheel in accordance with one embodiment of the invention;
[0020] FIG. 3 is a side structural view of a deformed forward steering wheel in accordance with one embodiment of the invention;
[0021] FIG. 4 is a top plan structural view of a steering wheel in accordance with another embodiment of the invention;
[0022] FIGS. 5 a - b are each a side structural view of a steering wheel in accordance with another embodiment of the invention;
[0023] FIGS. 6 a - b are each a side structural view of a steering wheel in accordance with yet another embodiment of the invention; and
[0024] FIG. 7 is a top plan structural view of a steering wheel in accordance with yet another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The configuration of a steering wheel according to the embodiments of the present invention is explained hereinafter with reference to the drawings.
[0026] FIG. 1 is a top plane structural view of a steering wheel 100 in accordance with one embodiment of the present invention. The steering wheel 100 comprises: a grip frame 10 ; one or more spoke frames 20 ; a supporting shaft 30 ; and at least one force-cushioning element 50 , wherein the grip frame 10 is connected and integrated by means of the spoke frames 20 and the supporting shaft 30 ; the grip frame 10 consists of an upper portion 12 and a lower portion 14 ; the force-cushioning element 50 is disposed between the upper portion 12 and the lower portion 14 ; the spoke frame 20 for connecting the lower portion 14 of the grip frame 10 and the supporting shaft 30 consists of an upper portion 22 and a lower portion 24 , wherein the force-cushioning element 50 is installed between the upper portion 22 and the lower portion 24 . The two ends of the force-cushioning element 50 are fixed respectively at the connection position between the upper portion 12 and the lower portion 14 by means of bolting or mechanical pressing. Similarly, the two ends of the force-cushioning element 50 are fixed respectively at the connection position between the upper portion 22 and the lower portion 24 . The force-cushioning element 50 is made of an elastic steel plate or elastic memory material.
[0027] FIGS. 2 a - 2 b illustrate a perspective view and a side view of the force-cushioning element 50 , respectively, in accordance with one embodiment of the present invention. In the present embodiment, the force-cushioning element 50 is an elastic plate, and is installed inside the grip frame and the spoke frames wherein the grip frame and the spoke frames are of a circular pipe design. In other embodiments, the force-cushioning element 50 is disposed outside, topside or underside of the grip frame and/or the spoke frames. In certain embodiments, the grip frame and the spoke frames are made of, e.g., circular metal pipe (hollow or filled), having one or multiple layers.
[0028] In this embodiment, the force-cushioning element is an elastic plate which is coplanar with the steering wheel. The elastic plate is rigid in the direction of rotation allowing the steering wheel to be rotated, yet elastic in the direction normal or substantially-normal to the plane of the gripping frame (i.e., the plane of the drawing in FIG. 1 ) allowing the steering wheel to be elastically deformed when the steering wheel is being impacted by the driver's body during collision so as to absorb the force of impact of the driver's body.
[0029] FIG. 3 is a side view showing a deformed steering wheel in accordance with one embodiment of the present invention. When the front portion of the steering wheel 100 is being impacted, at least one force-cushioning element 50 of the grip frame 10 and the spoke frames 20 will be elastically deformed so as to cushion the force and thereby to protect the driver. When the steering wheel 100 is under normal operation, the force-cushioning element 50 is rigid so that the steering performance of the steering wheel 100 is not influenced.
[0030] As shown in FIG. 4 , in another embodiment of the present invention, the grip frame 10 consists of an upper portion 12 and a lower portion 14 , wherein the lower portion 14 of the grip frame 10 and the supporting shaft 30 are connected by means of one or more spoke frames 20 ; at least one spoke frame 20 consists of an upper portion 22 and a lower portion 24 , wherein a force-cushioning element 50 is installed at the juncture between the upper portion 22 and the lower portion 24 .
[0031] FIG. 5 a - b illustrate a side structural view of a steering wheel in accordance with other embodiment of the present invention. As shown in FIG. 5 a , the steering wheel 100 includes a grip frame 10 ; one or more spoke frames (not shown); a supporting shaft 30 ; and a force-cushioning element 50 . The grip frame 10 is connected and integrated by means of the spoke frame and the supporting shaft 30 . As differentiated from conventional steering wheels, the grip frame 10 and spoke frame of the steering wheel 100 are movably-affixed to the supporting shaft 30 and have a certain play relative to the supporting shaft 30 . The force-cushioning element 50 is disposed at a position between the spoke frame and the supporting shaft 30 . In the present embodiment, the force-cushioning element 50 is a corner shaped elastic plate.
[0032] As shown in FIG. 5 b , the elastic corner plate is rigid in the direction of rotation (in any direction within the plane of the gripping frame) allowing the steering wheel to be rotated, yet elastic in a direction normal or substantially-normal to the plane of the gripping frame allowing the steering wheel to be elastically deformed when the steering wheel is being impacted by the driver's body during collision so as to absorb the force of the impact with the driver's body.
[0033] FIGS. 6 a - b illustrate a side structural view of a steering wheel in accordance with another embodiment of the present invention. As shown in FIG. 6 a , the steering wheel 100 includes a grip frame 10 ; a spoke frame (not shown); a supporting shaft 30 ; and a force-cushioning element 50 . As differentiated from conventional steering wheels, the grip frame 10 and spoke frame of the steering wheel 100 are movably-affixed to the supporting shaft 30 , and have a certain play relative to the supporting shaft 30 . The force-cushioning element 50 is disposed at a position between the spoke frame and the supporting shaft 30 . In the present embodiment, the force-cushioning element 50 is a rack 50 with a plurality of teeth. A positioning device 32 is installed on the supporting shaft 30 to interact with the rack 50 . Under normal operating conditions, the rack 50 is aligned with the positioning device 32 at a first position of the rack 50 , as shown in FIG. 6 a.
[0034] When the steering wheel 100 is being rotated, i.e., under a normal rotating force, the rack 50 is rigid with respect to the steering wheel 100 , and is geared with the positioning column 32 . However, when the steering wheel 100 is being impacted by the driver's body in a collision, the plane of the steering wheel 100 changes orientation (from that shown in FIG. 6 a to that shown in FIG. 6 b ). Thus, the rack 50 will be moved and re-aligned with the positioning device 32 at a second position of the rack 50 as shown in FIG. 6 b , and in doing so will cushion the impacting force. The impacting forced is cushioned during the process of deformation.
[0035] FIG. 7 is a structural view of a steering wheel in accordance with another embodiment of the present invention. In the present embodiment, a steering wheel 200 includes a grip frame 210 , one or more spoke frames 220 , and a supporting shaft 230 , wherein the grip frame 210 is an annular-shaped elastic plate or column. The entire spoke frame 220 is an elastic plate. The grip frame 210 and the spoke frames 220 are rigid in the direction of rotation (in any direction parallel to the plane of the gripping frame) allowing the steering wheel 200 to be rotated, yet can be elastically force-deformed in a direction normal or substantially-normal to the plane of the gripping frame allowing the steering wheel 200 to be elastically deformed when the steering wheel is impacted by the driver's body during a collision so as to absorb the force of the impact with the driver's body.
[0036] The outer surfaces of the grip frame 210 and the spoke frames 220 are covered by sponge or leather material so as to improve the comfort of gripping.
[0037] In accordance with other embodiments of the present invention, the force-cushioning element of the steering wheel also can be installed at the top portion of the supporting shaft so as to cushion the impacting force, e.g., of the driver's head, to the steering wheel.
[0038] In accordance with the present invention, the steering wheel comprises at least one force-cushioning element, or at least one part of the steering wheel is made from an elastic material. The steering wheel is rigid with respect to a normal force applied to the wheel to turn it and to steer the vehicle, so that the steering performance of the vehicle is not influenced. However, in the event of a frontal collision, the steering wheel will be impacted by the body of the driver, and correspondingly, it will be deformed as a result of it incorporating one or more force-cushioning elements. Thus, an injury to the driver can be avoided or greatly reduced.
[0039] The force-cushioning element is made of materials capable of being deformed in one direction but not in another direction. This is accomplished by providing specially-engineered materials and/or by providing conventional materials shaped so as to achieve the desired properties.
[0040] Energy absorption in a force-cushioning element occurs without limitation via a plastic deformation, an elastic deformation, or by the fluid dynamics of gases or liquids within the material.
[0041] The force-cushioning materials are selected without limitation from the group consisting of, e.g., soft steel, various metal alloys, polymers, such as, expanded polystyrene, polyurethanes, polyethers, or polyethylene, silica aerogels, and natural or synthetic fibers having uniform or random orientations.
[0042] 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.
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The present invention teaches a steering wheel for a vehicle comprising a grip frame; one or more spoke frames; a supporting shaft; and at least one force-cushioning element; wherein the spokes connect the grip frame to the supporting shaft; the grip frame and/or the spoke frames comprise two or more parts; the force-cushioning element is disposed between the parts; and the force-cushioning element is capable of being deformed by a force exerted by a driver colliding with the steering wheel whereby deforming the grip frame and/or the spoke frames.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention generally relates to a method for use in subterranean wellbores. More particularly, the invention relates to a method used to measure inflow profiles in subterranean injector wellbores.
[0003] 2. Description of Related Art
[0004] It is important for an operator of a subterranean injector wellbore, such as for an oil or gas well, to determine the inflow profile of the injector wellbore in order to analyze whether all or just certain parts of a specific zone are injecting fluids therethrough. This determination and analysis is useful in vertical, deviated, and horizontal wellbores. In horizontal wellbores, the amount of fluid flowing through a specific zone tends to decrease from the heel to the toe of the well. Often, the toe and sections close to the toe have very little and sometimes no fluid flowing therethrough. An operator with knowledge of the inflow profile of a well can then attempt to take remediation measures to ensure that a more even inflow profile is created from the heel to the toe of the well.
[0005] Thus, there exists a continuing need for an arrangement and/or technique that addresses one or more of the problems that are stated above.
BRIEF SUMMARY OF THE INVENTION
[0006] The invention comprises a method of determining the inflow profile of an injection wellbore, comprising stopping injection of fluid into a formation, the formation intersected by a wellbore having a section uphole of the formation and a section within the formation, monitoring temperature at least partially along the uphole section of the wellbore and at least partially along the formation section of the wellbore, injecting fluid into the formation once the temperature in the uphole section of the wellbore increases, and monitoring the movement of the increased temperature fluid as it moves from the uphole section of the wellbore along the formation section of the wellbore. The monitoring may be performed using a distributed temperature sensing system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention is more fully described with reference to the appended drawings wherein:
[0008] FIG. 1 is a schematic illustration of a wellbore utilizing the present invention;
[0009] FIG. 2 is a plot of a geothermal temperature profile along a horizontal wellbore;
[0010] FIG. 3 is a plot showing temperature profiles taken along a wellbore at different points in time, including during injection and while the well is shut-in;
[0011] FIG. 4 is a plot illustrating the movement of a temperature peak along the wellbore and relevant formation; and
[0012] FIG. 5 is a plot of the velocity of the temperature peak of FIG. 4 as it moves along the wellbore and relevant formation.
DETAILED DESCRIPTION OF THE INVENTION
[0013] FIG. 1 is a general schematic of an injector wellbore utilizing the present invention. A tubing 10 is disposed within a wellbore 12 that may be cased or uncased. Wellbore 12 may be a horizontal or inclined well that has a heel 14 and a toe 16 , or a vertical well. The horizontal section of the well may have a liner, may be open-hole, or may have a continuation of tubing 10 therein. Wellbore 12 intersects a permeable formation 18 such as a hydrocarbon formation. A packer 11 may be disposed around the tubing 10 to sealingly separate the wellbore sections above and below the packer 11 .
[0014] Wellbore 12 is an injector wellbore and the tubing 10 thus has injection equipment 20 (such as a pump) connected thereto near the earth's surface 22 . Injection equipment 20 may be connected to a tank 23 containing the fluid which is to be injected into formation 18 . Typically, the fluid is injected by the injection equipment 20 through the tubing 10 and into formation 18 . Tubing 10 may have ports adjacent formation 18 so as to allow flow of the fluid into formation 18 . In other embodiments, a liner with slots disposed in the horizontal section of the well may provide the fluid communication, or the horizontal section may be open hole. Perforations may also be made along formation 18 to facilitate fluid flow into the formation 18 .
[0015] A distributed temperature sensing (DTS) system 24 is also disposed in the wellbore 12 . The DTS system 24 includes an optical fiber 26 and an optical launch and acquisition unit 28 .
[0016] In the embodiment shown, the optical fiber 26 is disposed along the tubing 10 and is attached thereto on the outside of the tubing 10 . In other embodiments, the optical fiber 26 may be disposed within the tubing 10 or outside of the casing of the wellbore 12 (if the wellbore is cased). The optical fiber 26 extends through the packer 11 and across formation 18 . The optical fiber 26 may be deployed within a conduit, such as a metal control line. The control line is then attached to the tubing 10 or behind the casing (if the wellbore is cased). The optical fiber 26 may be pumped into the control line by use of fluid drag before or after the control line and tubing 10 are deployed downhole. This pumping technique is described in U.S. Reissue Pat. No. 37,283, which is incorporated herein by reference.
[0017] The acquisition unit 28 launches optical pulses through the optical fiber 26 and then receives the return signals and interprets such signals to provide a distributed temperature measurement profile along the length of the optical fiber 26 . In one embodiment, the DTS system 24 is an optical time domain reflectometry (OTDR) system wherein the acquisition unit 28 includes a light source and a computer or logic device. OTDR systems are known in the prior art, such as those described in U.S. Pat. Nos. 4,823,166 and 5,592,282, both of which are incorporated herein by reference. In OTDR, a pulse of optical energy is launched into an optical fiber and the backscattered optical energy returning from the fiber is observed as a function of time, which is proportional to distance along the fiber from which the backscattered light is received. This backscattered light includes the Rayleigh, Brillouin, and Raman spectrums. The Raman spectrum is the most temperature sensitive, with the intensity of the spectrum varying with temperature, although Brillouin scattering, and in certain cases Rayleigh scattering, are also temperature sensitive.
[0018] Generally, in one embodiment, pulses of light at a fixed wavelength are transmitted from the light source in acquisition unit 28 down the optical fiber 26 . At every measurement point in the optical fiber 26 , light is back-scattered and returns to the acquisition unit 28 . Knowing the speed of light and the moment of arrival of the return signal enables its point of origin along the optical fiber 26 to be determined. Temperature stimulates the energy levels of molecules of the silica and of other index-modifying additives, such as germania, present in the optical fiber 26 . The back-scattered light contains upshifted and downshifted wavebands (such as the Stokes Raman and Anti-Stokes Raman portions of the back-scattered spectrum), which can be analyzed to determine the temperature at origin. In this way, the temperature of each of the responding measurement points in the optical fiber 26 can be calculated by the acquisition unit 28 , providing a complete temperature profile along the length of the optical fiber 26 . In one embodiment, the optical fiber 26 is disposed in a u-shape along the wellbore 12 providing greater resolution to the temperature measurement.
[0019] FIG. 2 shows a graph of the geothermal temperature profile 29 of a generic horizontal wellbore. This profile shows at 30 a gradual increase in temperature as the depth of the well increases, until at 32 a stable temperature is reached along the horizontal section of the wellbore. The geothermal temperature profile is the temperature profile existing in the wellbore without external factors (such as injection). After injection or other external factors end, the wellbore will gradually change in temperature towards the geothermal temperature profile.
[0020] In one embodiment of this invention, in order to determine the inflow profile of a wellbore 12 , the wellbore 12 must first be shut-in so that no injection takes place. The temperature profile of the wellbore 12 changes if there is injection and throughout the shut-in period. FIG. 3 shows these changes.
[0021] Curve 34 is the temperature profile of the wellbore 12 during injection, wherein the temperature is relatively stable since the injected fluid is flowing through the tubing 10 and into the formation 18 .
[0022] Curve 36 represents a temperature profile of the wellbore 12 taken after injection is stopped and the well is shut-in. Curve 36 is already gradually moving towards the geothermal profile 29 . However, section 40 of curve 36 is changing at a much slower rate than the uphole part of the curve 36 because section 40 represents the area of the formation 18 which absorbed the most fluid during the injection step. Therefore, since this area is in contact with a substantial amount of fluid already injected in the formation 18 , this area takes a longer time to heat or return to its geothermal norm. Of interest, peak 42 is present on curve 36 because peak 42 is the area of wellbore 12 found directly before formation 18 (and not taking fluids). Therefore, a substantial temperature difference exists between peak 42 and section 40 .
[0023] Curve 38 represents a temperature profile of the wellbore 12 taken subsequent to the temperature profile represented by curve 36 . Curve 38 shows that the temperature profile is still heating towards the geothermal norm, but that the difference between peak 44 (peak 42 at a later time) and the section 40 are still apparent.
[0024] The object of this invention is to determine the velocity of the fluid being injected across the length of the formation 18 in order to then determine the inflow profile of such formation 18 . The technique used to achieve this is to re-initiate injection after a relatively short shut-in period and track the movement of the temperature peak ( 42 , 44 ) by use of the DTS system 24 .
[0025] FIG. 4 shows four curves representing temperature profiles taken over time. Curve 50 is a profile taken during shut-in, curve 52 is a profile taken after injection is re-started, curve 54 is a profile taken after curve 52 , and curve 56 is a profile taken after curve 54 . For purposes of clarity, the entire temperature profile of the wellbore has not been shown. Curve 50 includes a temperature peak 58 A that represents the temperature peak present during shut-in and found directly uphole of formation 18 . Temperature peak 58 A corresponds to temperature peaks 42 and 44 of FIG. 3 . Once injection is restarted, the slug of heated fluid represented by temperature peak 58 A is essentially “pushed” down the wellbore 12 , as is shown by the temperature peaks 58 B-D in time lapse curves 52 , 54 , and 56 . The temperature peak 58 A-D, as expected, decreases over time once injection is restarted.
[0026] By tracking the movement of the temperature peak 58 A-D down the wellbore 12 (through use of the DTS system 24 ), an operator can determine the velocity of the temperature peak 58 A-D as it moves down the wellbore 12 and the formation 18 over time. As shown in FIG. 5 , the velocity of the temperature peak 58 A-D is then plotted against depth across the length of the formation 18 . This plot shows a constant velocity at 60 immediately prior to the temperature peak reaching the formation 18 , a gradual decrease of velocity at 62 as the temperature peak moves away from the uphole boundary of the formation 18 , and a very low and perhaps zero velocity as the peak nears the downhole boundary of the formation 18 . From this plot, one can determine that the downhole portion of the formation 18 (that closer to the toe 16 ) is not receiving much fluid during injection in comparison to the uphole portion of the formation 18 . With this information, one can provide injection inflow profiles across the formation 18 , which profiles can be shown in percentage form (percentage of fluid being injected along the length of the formation 18 ) or quantitative form (with knowledge or a measurement of the actual surface injection rate). Thus, by monitoring the velocity of a heated slug (temperature peaks 58 A-D) across a formation 18 , the injection inflow profile of a wellbore 12 across a formation 18 may be determined.
[0027] Of importance, the shut-in period required to use the present technique is short in relation to the shut-in periods in some comparable prior art techniques. In some prior art techniques, the area of the formation 18 (see section 40 in FIG. 3 ) and not the area directly uphole of the formation 18 (see peaks 42 and 44 in FIG. 3 ) is monitored during the warmback period (and not the injection period) to determine the inflow profile. However, in wellbores that have been injecting for a long period of time, the area of the formation 18 (see section 40 ) must be monitored for a substantial period of time before the warmback curves begin to move towards the geothermal gradient and the relevant information can be extracted therefrom. With the present technique, the warmback period can be as short as 24 to 48 hours, since the temperature peaks 42 and 44 (used as previously stated) begin to shift towards the geothermal profile much more quickly. Thus, a process that would take weeks or months to complete using the prior art techniques can now be completed in several days using the present technique.
[0028] While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the scope of the invention.
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A method of determining the inflow profile of an injection wellbore, comprising stopping injection of fluid into a formation, the formation intersected by a wellbore having a section uphole of the formation and a section within the formation, monitoring temperature at least partially along the uphole section of the wellbore and at least partially along the formation section of the wellbore, injecting fluid into the formation once the temperature in the uphole section of the wellbore increases, and monitoring the movement of the increased temperature fluid as it moves from the uphole section of the wellbore along the formation section of the wellbore. The monitoring may be performed using a distributed temperature sensing system.
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RELATED APPLICATION
This application is a continuation-in-part to application Ser. No. 447,108 filed Dec. 6, 1989, now U.S. Pat. No. 5,031,931.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains to a sensor for mounting in motor vehicles for sensing a crash, said sensor generating a signal for deploying a passenger restraint system such as an air bag.
2. Description of the Prior Art
Air damped crash sensors have become widely adopted by many of the world's automobile manufacturers to sense that a crash is in progress and initiate the inflation of an air bag or tensioning of seat belts. These sensors are constructed from a ball and tube such as disclosed in U.S. Pat. Nos. 3,974,350; 4,198,864; 4,284,863; 4,329,549 and 4,573,706.
The ball-in-tube sensor currently in widespread use has a magnetic bias. Both ceramic and Alnico magnets are used depending on the amount of variation in bias force caused by temperature that can be tolerated. Sensors used in the crush zone of the vehicle and safing or arming sensors used both in the crush zone and out of the crush zone, use ceramic magnets since they can tolerate a wide variation in bias force. Alnico magnet are used for the higher biased non crush zone discriminating sensors where little variation in the bias can be tolerated. If a spring bias is used in place of the magnetic bias as shown in Thuen U.S. Pat. No. 4,580,810, the variation in the bias force with temperature can be practically eliminated.
In the conventional ball-in-tube sensor, two cantilevered contacts are bridged by the ball and both the ball and the contacts may be gold plated to minimize the contact resistance. If the sensing mass instead of bridging the contacts pushed one contact into another, the gold plating on the ball could be eliminated.
OBJECTIVES AND SUMMARY OF THE INVENTION
A crash sensor according to the invention is adapted for installation on an automotive vehicle equipped with a passenger protective device such as an inflatable air bag or seat belt tensioner. When such vehicle is subjected to deceleration of the kind accompanying a crash, the air bag is inflated to provide a protective cushion for the occupant or the seat belt is pulled back against the occupant holding him in a safe position.
A sensor constructed according to the invention comprises a housing adapted to be mounted on the vehicle in a position to sense and respond to deceleration pulses. Within the housing is a body containing a tubular passage in which is mounted a movable deceleration sensing mass. The mass is movable in response to a deceleration pulse above a threshold value from an initial position along a path leading to a normally open switch that is connected via suitable wiring to the operating mechanism of an inflatable air bag or seat belt tensioner.
A biasing spring or magnet acts on the deceleration sensing mass to bias the later to its initial position under a preselected force which must be exceeded before the sensing mass may move from its initial position. When the sensing mass is subjected to a deceleration creating an inertial force greater than the preselected biasing force it from its initial position toward its air bag or set belt tensioner operating position. Movement of the sensing mass is fluid damped thereby requiring a finite period of time for the sensing mass to move from its initial position to its operating position during which time the deceleration must continue to exceed the bias force.
According to another feature of the invention, it has been discovered that increasing the biasing force from 2 to 3 G's of the conventional gas damped sensors to approximately 6 G's can solve the late-firing problems present in the conventional sensors, without affecting the sensitivity of the sensor for other crashes. Preferably, the level of the biasing force for crush zone crash sensors is increased to greater than 5 G's and, more particularly, to the range of within 5-10 G's.
It is an objective of this invention to provide a contact design which eliminates contact bounce.
It is another objective of this invention to utilize the magnetic field which is present in a magnetically biased sensor to cause one contact to be held against a second contact when the sensor triggers.
It is another objective of this invention to utilize one contact as a biasing force against the ball which is pushed into a second more rigid contact thus eliminating both contact bounce and the magnet.
It is a further objective of this invention to devise a smaller, simpler and less expensive sensor.
Still another objective of this invention is to eliminate the need for gold plating on the sensing mass.
It is still another project of this invention to provide a level of higher biasing force than is previously known in damped crush zone sensors to eliminate the late firing problems of such crash sensors on marginal crashes.
Other objectives and advantages will become apparent from the description of the preferred embodiments below.
BRIEF DESCRIPTION OF THE DRAWINGS
Crash sensing apparatus constructed in accordance with the preferred embodiments of the invention is illustrated in the accompanying drawings, wherein:
FIG. 1 shows a schematic diagram for a typical passenger restraint system;
FIG. 2 is a sectional view of the apparatus in accordance with this invention for installation on an automotive vehicle;
FIG. 3 represents an embodiment similar to the embodiment of FIG. 2 with an alternate configuration of the contacts;
FIG. 4 shows the embodiment of FIG. 3 with the sensor activated;
FIG. 5 represents an embodiment similar to the embodiment of FIG. 1 with an alternate position for the reed switch;
FIG. 6 shows a sectional view of another embodiment of the invention with spring-biasing;
FIG. 7 is a view similar to FIG. 4, with the sensor activated; and
FIGS. 8 and 9 show other embodiments of a sensor with spring bias.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An apparatus constructed in accordance with the invention is illustrated in FIG. 2 and is adapted for use in conjunction with an automotive vehicle or truck (not shown) preferably accommodated within a closed, metallic housing (not shown).
The sensor apparatus is designated generally by reference 6 in FIG. 2, and comprises a body 12 formed of suitable plastic material and having a cylindrical portion 8 closed at one end by a wall 9. At the other end of the body is a cylinder skirt 10. Within cylindrical portion 8 there is a bore 12. The inner surface of the portion 8 is provided with two opposed semi-spherical, concave seats 15, 15A. Fitted into the bore 12 is a metallic sleeve 16 having a smooth inner surface forming a linear passage 17 and on the outer diameter midway along the sleeve is groove 13 in which is accommodated a rubbery sealing and vibration isolating ring 14 which also holds the sleeve in place.
Accommodated within the passage 17 is a spherical, magnetically permeable, electrically conductive sensing mass 18, the radius of which corresponds substantially to that of the seats 15, 15A and the diameter of which is slightly less than that of the passage 17.
Fixed in the bore 12 is a cylindrical plug 19 formed of electrically insulating material, the plug being fixed in the chamber in any suitable manner, such as by cement, by ultrasonic welding, by crimping the rim of the skirt, or a combination thereof.
Plug 19 includes a reed switch 19A with two normally open contacts 27, 28.
Means are provided for applying magnetic biasing force on the mass 18 and comprises an annular magnet 33 having a hole 34 therethrough in which is received a mounting ferrule 35 forming a part of the body 8 and projecting beyond the wall 9.
To condition the apparatus for operation, the sensor mechanism is fitted into the housing and the latter is fixed to a vehicle with the longitudinal axis of the passage 17 parallel or at a predetermined angle to the longitudinal axis of the vehicle. As shown in FIG. 1, the conductors 4 and 5 coupled to contacts 27 and 28 respectively, then may be connected in circuit with the vehicle battery 30, activator 31, and the restraint device or air bag 32.
The magnet will exert a magnetically attractive force on the sensing mass 18 so as normally retain the latter in an initial, inactive position on the seat 15 at the closed end of the passage 17.
If the vehicle on which the sensor is mounted is traveling in the direction of the arrow A (FIG. 2) the sensing mass 18 will remain in its position until such time as the vehicle experiences a deceleration pulse greater than the biasing force exerted on the mass 18 by the magnet 33. If such deceleration pulse is of sufficient magnitude and duration, the sensing mass 18 will move from the position shown in FIG. 2 to an operating position, in which the mass causes contacts 27 and 28 to close and complete an electrical circuit rom the battery 30 to the activator 31 so as to activate the air bag 32.
Contacts 27 and 28 are made from a magnetically permeable materials such that in the presence of a magnetic field contacts 27 and 28 will bend toward each other closing the circuit as in conventional reed switches. When ball 18 moves to a position adjacent to contacts 27 and 28 the magnetic flux lines travel between the ball 18 and reed switch 19A of magnetic circuit element 40. This concentration of flux lines caused by the ball causes contacts 27 and 28 to bend toward each other making contact.
When the ball returns to the cylinder at the end of the crash, the concentration of flux lines is removed and contacts 27 and 28 spread apart.
This arrangement eliminates contact bounce since once the two contacts make contact the magnetic force holding them together exceeds the magnetic force needed to cause initial contact.
FIG. 3 shows an alternate configuration herein reed switch 19A has been replaced by a reed switch 19B having three contacts 40, 41, 42 disposed in a standard single pole, double throw arrangement. When the sensor is inactive, ball 18 is biased to the right by magnet 33, and contact 40 touches contact 41. When ball 18 moves to the left under the effects of acceleration, contact 40 disengages from contact 41 and touches contact 42 as shown in FIG. 3.
Although reed switch 19A shown in FIG. 2 is illustrated as being mounted in the sensor plug 19, an alternative approach would be to make use of a standard reed switch 19C imbedded in the body 8 as shown in FIG. 5. Contacts 27' and 28' of switch 19C perform in the same manner as contacts 27 and 28 in FIG. 2.
An alternate embodiment of the sensor is shown in FIG. 6 generally as 100. Instead of a magnet and a reed switch contact 107 has a flexible extension 109 which presses on the ball providing the necessary bias. During a crash, the ball 118 moves toward the front of the vehicle to the right in FIG. 6, however its motion is opposed by the contact biasing force and a difference in pressure across the ball. This pressure differential is gradually relieved by the flow of the gas through the clearance between the ball and the cylinder. The force exerted by the extension 109 against the ball at all times exceeds the inertial forces caused by the vibrations acting on the contact. Thus, the contact 107 always remains touching the ball 118. If the crash is of sufficient severity, ball 118 move to the right sufficiently to cause contact 107 to touch contact 108 completing the electrical connection (as shown in FIG. 7) and initiating a restraint device in a manner similar to FIG. 2. Since contact 108 is rigid and contact 107 is pushed substantially against the ball neither contact will vibrate and thus solid contact closure results.
In FIG. 8, a sensor 120 is shown with a flexible contact 121 and a rigid contact 122. This sensor operates the same Way as the sensor of FIGS. 6, 7. FIG. 9 shows yet another arrangement for the flexible contact.
In the embodiments shown herein, the sensing mass is not part of the electric circuit. Therefore, the need for gold on the sensing mass can be eliminated resulting in a less expensive and more accurate sensor. In the embodiment shown in FIGS. 6-9, the need for the magnet is also eliminated resulting in a much smaller and simpler sensor. Also, since only a single contact is made instead of the bridging of two contacts in the conventional ball-in-tube sensor, the size of the sensing mass can be reduce further reducing the size and cost of the sensor.
Naturally, other types of sensors could make use of this invention for improved contact closures.
This invention is particularly useful when sensors are placed in the crush zone of the vehicle. The crush zone is that portion of the vehicle which undergoes significant plastic deformation during the accident and where both longitudinal and cross axis vibrations are of significant magnitude and can seriously effect the sensor behavior in marginal crashes.
Based on the study of a car crash library, it has been discovered that a standard crush zone sensor with a bias of 2-3 G's triggers late for a number of pulses between 12 and 16 MPH. A significant improvement can be made in a viscous damped sensor by increasing the bias to the range of within 5-10 G's to reduce the incidence of sensor triggering on long duration pulses which are indicative of the sensor not being in the crush zone.
If a sensor is allowed to fire later than about 30 milliseconds after the beginning of a crash pulse the resulting deployment of the occupant restraint system may cause harm to the occupant.
A gas-damped crash sensor with a 2.2 G bias can easily fire substantially later than 30 ms provided that a relatively mild crash pulse continues for this period. If the bias is increased to above 5 G's, the possibility of late firing is eliminated for all crashes except those which continue to be severe or for which the crash pulse continues due to a secondary collision. Bias levels above about 10 G's do not permit effective crash sensing even in the low (1-30 ms). However, the parameters of a sensor, such as the clearance between the sensing mass and the cylinder or the travel of the sensing mass, can be adjusted to obtain the required sensitivity when the bias level is changed. Thus, the several aforenoted objects and advantages are most effectively obtained. Although some somewhat preferred embodiments have been disclosed and described in detailed herein it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
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Conventional ball-in-tube, gas-damped, crash sensors utilize a gold plated ball to bridge two contacts. When the ball senses acceleration (deceleration) in the longitudinal direction of a cylinder of sufficient magnitude and duration, it moves to where it bridges the contacts, completing the electrical circuit and initiating deployment of a safety restraint system. A switch activated by magnetic flux is combined with this type of gas-damped sensor to provide a solid and reliable contact duration and ensure the correct functioning of the sensor. The level of biasing force for crash zone crash sensors of this type has been increased to avoid late firing problems on marginal crashes.
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FIELD AND BACKGROUND OF THE INVENTION
This invention relates to a low mass-breakerless ignition distributor as may be used with internal combustion engines for compact and sub-compact automotive vehicles, for example.
Reduced available space and necessary weight reduction considerations dictate that such distributors be of compact size and employ light weight, stable components capable of holding adjustment and alignment and of withstanding the high shock and vibration encountered in the engine compartments of four cylinder automotive vehicles.
For the above and other reasons and the trend towards the increasing use of electronic ignition systems in motor vehicles, the distributors for such applications preferably ought to be of the breakerless variety and to employ electrical or electronic sensor, pickup trigger or timing signal generating devices, which may include semiconductor detecting, switching and/or signal processing circuitry provided therewith within the distributor housing.
The electrical and physical characteristics of such pickup devices, however, render them particularly vulnerable to damage due to the corrosive environment and electrostatic charges developed by the highly charged and ionized atmosphere, which exists within the interior of the distributor housing and may be conducive to arcing and arc flash-over from the distributor rotor electrode to the pickup.
Accordingly, the present invention seeks to provide a breakerless ignition distributor, which is of low mass, light weight and stable construction for use in high shock and vibration environments encountered in such automotive engines.
Related objects are to provide a breakerless distributor, which has an electronic pickup and associated circuitry within the distributor housing and which includes mechanical and electrical constructional features to protect the pickup structure from mechanical and electrical damage and reduce the possibility of accidental flashover thereto.
Other objects are to provide a breakerless ignition distributor, which is of simple, inexpensive and compact construction, is composed of a minimum number of parts, and may be readily assembled and disassembled for inspection, repair and replacement of the components thereof.
SUMMARY
According to the present invention, there is provided a low mass, breakerless ignition distributor, which uses a Hall Effect switch or electrical pickup and associated electrical and solid state electronic circuitry contained in an encapsulated module integrally formed on an insulated timing or base plate within the distributor housing. The distributor also features a one piece distributor rotor unit comprising a thin insulate disc member, which is readily detachably received on one end of the engine driven rotor shaft and carries a rotor distributor blade on one side thereof, and a ferrous metallic, rigid stiffener or reinforcement plate, which is molded in and carried on the other side of the rotor disc. The stiffener plate has a number of integrally formed, circumferentially spaced interrupter vanes depending therefrom into the space between the magnet and Hall Sensor element of the pickup structure of which the Hall Sensor element is disposed radially outwardly of the magnet and the interrupter vanes. The stiffener plate further includes an integrally formed grounding tab connection, which contacts the steel rotor shaft of the distributor when the rotor unit is mounted in place on the end of the rotor shaft, so that the interrupter vanes and the stiffener plate can be electrically grounded through the rotor shaft to divert any arc flashover, which may occur within the distributor cap, away from the pickup structure and to conduct it instead, through the grounded interrupter vanes and rotor shaft, thereby to protect the pickup structure and electronic circuitry within the distributor against damage from such arcing.
The above and other objects, advantages and features of the invention will appear more fully from consideration of the following detailed description, made with reference to the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional elevational view of a low mass, breakerless ignition distributor in accordance with the present invention;
FIG. 2 is a top plan view of the distributor of FIG. 1;
FIG. 3 is a plan view of the distributor of FIG. 1 with the distributor cap and the distributor rotor unit removed;
FIG. 4 is a vertical sectional view with parts broken away and taken in the direction 4--4 of FIG. 2;
FIG. 5 is a top plan view of a base plate component employed in the distributor of FIGS. 1 and 3 in which the spark timing is mechanically advanced;
FIG. 6 is a top plan view of another form of base plate mounting component with an integrally formed Hall Sensor pickup structure for use in a distributor in which the spark timing is electronically advanced;
FIG. 7 is an enlarged, vertical sectional elevation view with parts broken away taken in the direction 7--7 of FIG. 3;
FIG. 8 is a top plan view of the distributor rotor unit employed in the distributor of FIG. 1; and
FIG. 9 is a bottom view of the distributor rotor unit of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2 of the drawings, the distributor 10 comprises a cylindrical bowl-shaped, machined housing 12, which is formed of cast aluminum material, and a towered dome-shaped distributor cap 14, which is formed of electrically insulative, thermal plastic, polyester material exhibiting high mechanical strength and impact qualities and high electrical dielectric characteristics. The distributor cap has a pair of upstanding, diametrically oppositely disposed, integrally formed ears or posts 16 thereon by which it may be releasably attached by threaded and cross-slotted screws 17 to a flanged rectangular platform portion 18, which is integrally, but asymmetrically formed at the upper end of the housing. Extending downwardly from the bowl-shaped housing is an integrally formed tubular shank or stem portion 20 with a stepped mounting flange 22 at its lower end, which is received in an opening (not shown) in and is suitably secured to the engine block. Stem portion 20 includes an upper thrust bearing 23 and a lower sleeve bearing 24 in which is journalled the distributor rotor shaft 26, which is formed of machined steel and is suitably coupled to and is rotatably driven from the electrically grounded engine, depicted diagrammatically at 28 herein.
Coverning the upper end of the bowl-shaped housing 12 is a generally circularly-shaped stationary base plate 30, which carries a moveable timing plate 40 thereon. Plate 30 has a centrally located aperture 32 therein and is formed with a pair of diametrically oppositely disposed apertured ears 33 thereon underlying the raised mounting posts 16 on the distributor cap, as shown in FIGS. 3, 4 and 5 herein. The threaded attachment screws 17 extend through and secure the distributor cap 14 and base plate 30 to the platform portion 18 of the housing 12 to which the base plate is further releasably attached by spring clips 34.
Timing plate 40, which carries the magnet and Hall Sensor element of the pickup assembly 50 thereon, is formed of a plastic material as the distributor cap 14 and base plate 30 and has a central aperture therein surrounded by a short collar or sleeve 42 shown in FIG. 1 herein. Sleeve 42 projects axially downwardly from the lower side of the timing plate and is received within the central aperture 32 of the base plate 30 in which the timing plate is thus mounted for pivotal movement about the central axis of the distributor. An integrally formed circular boss 44 projecting from the lower side of the timing plate 40 is received in an elongated arcuate slot 36, (FIG. 5), which is provided in the base plate 30 against which the timing plate is resiliently yieldably held by a thin spring slip or strip 37 that is located on the underside of the timing plate and is secured to the boss 44 by an attachment screw 38. An integrally formed tab 39 on the upper surface of the base plate 30 overhangs the innermost end of the timing plate and holds it against the base plate, while allowing arcuate movement of the timing plate thereon.
In the embodiment shown in FIG. 1, movement of the timing plate 40 is effected from a vacuum actuator unit 60 coupled to an ear 46, which is integrally formed on the outermost end of the timing plate and extends radially through the distributor cap. As shown in FIGS. 2 and 3, the actuator 60 is of the double chamber, spring biased, diaphragm-operated variety and has an L-shaped mounting bracket 62 secured thereto by which it is detachably mounted to the housing platform portion 18, as by mounting screws 64.
One chamber or side of the flexible, impervious diaphragm 65 is exposed to a source of engine vacuum, which is conducted thereto and applied to a centrally located tubular spout or stem 66 thereon. The other chamber, or atmospherically exposed side of the diaphragm, is connected to an actuator bail or link 67 having a short straight section and a longer arcuate section, which curves around an external portion of the distributor cap and is hooked to the ear 46 on the timing plate 40 for movement of the latter in a direction to advance the engine spark timing with increasing engine vacuum.
Below the plates 30 and 40 is located the centrifugally operated governor mechanism 70 shown in FIG. 1. The governor mechanism is rotatively driven from the rotor shaft 26 and includes a governor weight support plate 71, which is fixed to the rotor shaft, and a pair of sintered powder metal stops or cam blocks 72, which are fixedly mounted on the support plate and bear against the governor weights one of which is shown at 73. The governor weights 73, which are also formed of powdered metal, are pivotally and swingably mounted on diametrically opposed, vertically extending pins, one of which is shown at 74, carried on and fixed to a rotatable flange plate 75 located above the support plate 71. The upper end of each pin extends through the flange plate 75 to provide a mounting post or anchor for one end of a different one of a pair of governor springs, one of which is shown at 76 and is provided for each governor weight. The other end of each spring is fastened to a different one of a pair of upstanding anchor posts, one of which is shown at 77, each secured to a different one of the cam blocks 72. Plate 75 is fixed to the lower end of a tubular metallic sleeve 78, which surrounds and receives the rotor shaft 26 and is relatively rotatably movable thereon by the movement of the governor weights to adjust the angular position of the sleeve 78 relative to the rotor shaft 26 in a direction to advance the engine spark timing with increasing engine speed.
The pickup or sensor assembly 50 is preferably of the Hall Effect variety, the components of which are encapsulated in a pair of upstanding, spaced apart protuberances 51 and 52, which are integrally formed on the molded timing plate 40 employed with the mechanically spark advanced distributor of FIG. 1. Where the spark timing is electronically advanced, the timing plate 40 is eliminated and the pickup structure 50 provided on the stationary base plate 30', as shown in FIG. 6. In such case, the vacuum actuator unit 60 and the governor mechanism 70, including the sleeve 78, would also be eliminated from the distributor structure.
The innermost or inwardly located protuberance 51 of the pickup structure 50 contains a radially extending bar magnet 53 and an inverted, L-shaped pole piece 54, which is affixed to one end and overhangs the other or free end of the magnet. The outwardly located protuberance 52 is spaced and separated from the protuberance 51 by a slot or air gap 55 and contains the magnetic field responsive Hall element 56 and another inverted L-shaped pole piece 57, which is located radially outwardly behind and overhangs the Hall element pole piece 57 has an inwardly extending pole face, which confronts and is aligned with the outwardly extending pole face of pole piece 54 and is spaced therefrom by the width of the slot or air gap 55 between the free end or pole of the magnet 53 and the Hall element 56. Hall element 56 is mounted on a ceramic substrate 58 and is located directly in the path of the magnetic flux or field of the permanent magnet 53 in a magnetic circuit, which extends from the free end or pole of the magnet radially outwardly across the air gap and through the Hall element and pole piece 57 and then radially inwardly across the air gap between the aligned pole faces of pole pieces 57 and 54 and back through pole piece 54 to the other pole of the magnet.
The ceramic substrate 58 also carries the electronic voltage regulating, signal shaping, amplifying and processing circuitry, which is associated with the Hall Sensor and may be of the character referenced in U.S. Pat. No. 3,875,920 for example. A three conductor harness 59, a part of which is encapsulated within the timing plate 40 of FIG. 3 or the base plate 30 of FIG. 6, is connected to the Hall element and semiconductor circuitry provided as an integrated semiconductor circuit chip on the substrate 58. The harness supplies the necessary operating voltage to the circuitry on the substrate and conveys the electrical switching signal derived therefrom to an externally located electronic control or switching unit diagrammatically depicted at 80 in FIG. 1 herein. For the mechanically advanced distributor, the electronic control unit 80 may be of the character shown for example in U.S. Ser. No. 743,021, now U.S. Pat. No. 4,106,460 or 743,824, both filed Nov. 18, 1976, while, for the electronically advanced distributor, the control unit may be of the character shown in U.S. Ser. No. 752,490 filed Dec. 20, 1976, all of common ownership herewith. The control unit 80, of course, controls the energization and deenergization of the ignition coil 81 from a source of low tension energy, shown as the negatively grounded vehicle battery 82 to develop the electrical high tension to the engine spark plug to ignite the combustable mixture within the engine cylinders and power the engine.
The high tension energy is sequentially distributed to the engine spark plugs 83 by the distributor rotor unit 90, which is readily detachably received and mounted on the upper end of the governor mechanism-actuated tubular sleeve 78 extending through the centrally apertured base plate 30 and timing plate 40. The rotor unit also carries interrupter structure cooperating with the pickup or Hall Sensor for switching the signal developed by the Hall element in synchronism with the rotation of the distributor rotor shaft by the engine.
As shown in FIGS. 1, 8 and 9, the distributor rotor unit 90 is a unitary or one piece structure including a molded disc member 91, which carries an electrically conductive rectangular-shaped distributor blade electrode 92 on one side thereof and a circular array of metallic interrupter vanes 93 on its flat other or lower side. Disc 91 is a comparatively thin member, which is formed of electrically insulative thermal plastic polyester material of a thickness of from five percent (5%) to approximately 10% or less than its diameter, and has an integrally formed, centrally located tubular sleeve 94, which projects axially downwardly from the flat lower surface thereof and slips over to be received on the upper end of the rotor sleeve 78 in close fitting relation therewith. An integrally formed rib or spline 95 located internally of the sleeve 94 is received within a keyway slot 96 cut in the upper end of the rotor sleeve 78 to provide a positive drive connection for the distributor rotor unit 90 from the engine driven rotor shaft 26. Reinforcement ribs 98 are provided on the upper surface of the disc 91, which further includes a radially outwardly disposed, upstanding mount or pedestal 100, a centrally located tubular post 101, and an outwardly disposed raised pad 102 located diametrically opposite the pedestal 100. Pedestal 100 provides an elevated rectangular mount for the blade-like distributor rotor electrode 92 and an overlying flat conductive spring 104, which overhangs the post 101 and is attached to the top of the pedestal with the electrode 92 by an attachment screw 105. Pad 102 provides a mass of material for balancing the disc, while the post 101 provides a stop for the spring 104.
Embedded in the plastic material of and carried on the flat underside of the rotor disc 91 is a thin, rigid metallic stiffener or reinforcement plate 110. Plate 110 is of slightly lesser diameter than and is disposed inwardly of the periphery of the overhanging disc 91 and has a plurality of openings therein for flow of the plastic material of the disc therethrough during the molding of the disc to affix the stiffener plate 110 thereto. The central portion of the stiffener plate is pierced or lanced with a three-sided rectangular slit and is struck out of the plane thereof to form a rectangular opening 111 therein, which surrounds or circumscribes the exterior of the tubular sleeve 94. The struck out central portion of the plate is then bent downwardly to form a depending tab 114, which extends into the interior of the tubular sleeve 94 to contact the upper end of the metallic sleeve 78, as shown in FIGS. 1 and 9.
The stiffener plate 110, which is formed of a flat rigid piece of 1010 SAE steel, reinforces and stabilizes the rotor disc 91 and reduces the amount of material employed in the formation thereof in addition to providing a carrier for the interrupter vanes 93, which are of integral formation with the plate. The vanes 93 are provided in a number corresponding to the number of cylinders in the engine in which the distributor is employed and are equally angularly spaced around the circumferential periphery or edge of the plate 110 with intervening equally spaced arcuate openings 112 between adjacent vanes and are displaced the same radial distance from the center of the plate. As shown in FIGS. 1 and 9, the vanes are of arcuate-shaped cross-section and depend downwardly axially from the plane of the plate 110 to extend into the space or slot 55 between the magnet 53 and Hall element 56 of the pickup sensor 50 when the distributor rotor unit 90 is mounted in place in the distributor.
The plastic distributor cap 14 is attached to the distributor housing 12 as previously described and is formed with a plurality of upwardly, longitudinally extending towers 140, 142 each of which has an electrically conductive electrode 144, 146 inserted or integrally moulded therein. Each tower receives a different one of a plurality of ignition cables or conductors (not shown) by which the centrally located tower electrode 146 is connected to the high tension side of the vehicle ignition coil 81 and the radially outwardly located tower electrodes 144 are connected to the corresponding spark plugs 83 of the engine.
At its lower or inner end projecting into the interior of the distributor cap, the central electrode 146 is swaged about a graphite sphere 148, which contacts the inwardly located end of the spring 104 to conduct the high tension ignition energy from the ignition coil to the blade-like distributor electrode 92 carried on the distributor rotor unit 90. The outwardly located end of the distributor rotor blade is spaced slightly from the lower ends of the inserts 144, which constitute the output or spark plug associated electrodes of the distributor, for transfer of high tension energy from the distributor blade 92 to an adjacent output electrode in the form of an electrical spark discharge therebetween. It will be noted that the distance between the rotor blade 92 and an adjacent interrupter vane 93 on the stiffener plate 110 as measured along (a) the vertical frontal surface of the raised pedestal 100, (b) the upper and lower surfaces of the portion of the disc member 91 overhanging the stiffener plate 110 and (c) the thickness of the plastic disc member 91 is greater than the distance between the rotor blade and an adjacent output electrode even when the rotor blade is positioned between an adjacent pair of output electrodes, as shown in FIG. 2, thereby decreasing the possibility of accidental arc flashover between the distributor blade and the interrupter vanes under normal loaded, closed circuit operating conditions of the ignition system.
However, under unloaded conditions of the ignition coil or an open circuit or disconnected condition of an engine spark plug, there is a possibility of drawing an arc from the distributor blade due to the highly ionized and electrostatically charged atmosphere within the distributor. This atmosphere, as previously mentioned, may deleteriously affect and be harmful to the charge-sensitive semiconductor Hall Sensor element and the integrated circuitry carried on the ceramic substrate 58 of the pickup 50. Moreover, should the integrated circuit chip module carried on the substrate be struck by an arc discharge from the distributor blade, as can occur for example during an unloaded condition of the ignition coil or open circuit condition of an engine spark plug, the expensive delicate circuitry thereon can be damaged.
It is for these reasons, therefore, that the interrupter vanes 93 are grounded through the integrally formed grounding tab connection 114 on the stiffener plate to the rotor shaft 26 through sleeve 78, which are at the electrical ground or reference potential of the return circuit side of the battery 82 and thus provide a path to ground for electrostatic charges within the distributor. Any stray or accidential electrical discharge that might emanate from the distributor rotor blade electrode under the aforementioned or related conditions will be diverted away from the delicate semiconductor components of the pickup and associated electronic circuitry and conducted instead to ground through the interrupter vanes and rotor shaft. The increased spacing or surface distance between the raised distributor electrode and adjacent interrupter vane also aids in attenuation of and lessening the tendency of any spark formation therebetween. The pickup structure may thus be protected by the above described mechanical and electrical expedients and design considerations of the distributor rotor unit itself without the need for additional protective circuitry within the pickup structure or in the external control unit.
From the foregoing it will be seen that the described distributor is characterized by and features an integral rotor and shutter assembly which greatly facilitates and simplifies the installation and removal of the rotor and shutter unit for inspection and replacement and reduces the cost of manufacture and fabrication thereof. The rotor and shutter assembly includes a stiffener plate, which permits the use of a thin rotor disc to reduce the mass of the distributor and enables the shutter to be molded and secured to the rotor disc. The stiffener plate rigidifies and strengthens the rotor disc and prevents warpage and out-of-roundness that would otherwise be encountered by the use of a thin rotor disc. In addition, it provides a carrier for the interrupter vanes of the shutter for the Hall Sensor assembly and by reason of the electrical ground return circuit path provided thereby, it also affords a measure of protection to the Hall Sensor and electronic assembly from arc flashover within the distributor.
While the distributor has been illustrated for use in a four cylinder engine, the principles employed therein may be applied to such distributors for larger engines as well.
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An automotive type ignition distributor featuring a Hall Effect pickup and associated electronic circuitry and a combined distributor rotor and interrupter unit, which distributes the high tension energy to the spark plugs of the engine, acts as an interrupter for the Hall Effect Pickup and provides a return circuit path to ground for electrostatic charges developed within the distributor to protect the semiconductor components within the distributor from damage due to arc flashover.
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This is a continuation of International Application PCT/GB98/00573, with an international filing date of Feb. 24 th , 1998, which claims priority to a British application 9704003.4, with a filing date of Feb. 26 th , 1997.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention generally relates to a mounting of a child-restraint system in a vehicle. The invention has been devised in a relation to such mounting in a road vehicle, and will hereafter be described in such a context, but it will be appreciated the invention may be more broadly applicable to other vehicles.
2. Discussion
Safety considerations and, in some areas, legislation, encourage small children traveling in motor vehicles to be restrained by equipment designed specifically for this purpose. The safety belts or other appliances usually provided in motor vehicles for assisting the safety of adults traveling in the vehicle by restraining them and preventing them from being thrown about within the vehicle in the event of an accident are not suitable for restraining children smaller than a certain size. The item of equipment most commonly used for child-restraint in motor vehicles is a so-called “child's safety seat,” which is fitted in the vehicle in one of the seats thereof and provides seating accommodation of a size to accept a small child and is provided with restraining straps or the like to hold the child in the safety seat.
It is, of course, important that such a child's safety seat should be securely held in position in the vehicle. Fixing of a safety seat by use of the safety belts provided for adult restraint is one currently acceptable method. Other methods to improve the current state of the art are always desirable, particularly in the area of safety. Accordingly, there is a desire to provide a seat of a vehicle with mounting means being sufficiently strong and rigid to hold the child-restraint system in place if the vehicle should suffer an accident. At the same time, the mounting means should not interfere with the comfort and/or convenience of the seat when it is not in use for securing a child-restraint system.
In particular, there is a draft international standard known as ISOFIX for standardized universal attachment of child-restraint systems to vehicles. ISOFIX Scheme D employs two lower rigid (or semi-rigid) anchorages in a defined area of the seat bight (i.e. the region of intersection of the surfaces of the seat cushion and backrest portions), and an additional anchorage for use with a tether strap. The lower anchorages are designed to be used with tether hooks, small push-button buckles, or ISOFIX connectors. The dimensions and disposition of the lower anchorages are specified in the ISOFIX standard.
SUMMARY OF THE INVENTION
It is broadly the object of the present invention to meet the above-described requirements as far as possible, in providing ISOFIX lower anchorages.
According to the one aspect of the present invention, the present invention provides a vehicle including a seat and a mounting means for mounting a child-restraint system in relation to said seat, said mounting means comprising a base portion secured to the vehicle structure and/or seat and a mounting portion extending to an accessible position upon the seat and adapted for engagement by the restraint system, such mounting portion being able to be removed from its position upon the seat when it is not required to be used.
According to another aspect of the invention, the present invention provides a mounting means for mounting a child-restraint system in relation to a vehicle seat, including a base portion adapted to be secured in relation to the vehicle structure and a mounting portion adapted to extend to an accessible position upon the seat and removable from said position upon the seat when not required to be used.
Preferably, the base portion of the mounting means is connected or adapted for connection to the vehicle structure (e.g. the floor pan of the vehicle) beneath the lower end of a backrest portion of the seat and at the rear of a cushion portion of the seat, whilst the mounting portion is arranged to extend between the backrest and cushion portion of the seat for engagement by the restraint system above the rear of the cushion portion and at the bottom of the backrest portion, i.e. adjacent the bight of the seat.
The mounting portion may be completely removable from the base portion, or alternatively may be movably (e.g. pivotally) connected thereto so as to be movable between operative and stowed positions.
In the case of a mounting means whose mounting portion is completely removable from the base portion thereof, the portions may have engagement by a releasable fastening, for example of a type analogous to that used for the fastening buckles for vehicle safety belts. To engage the mounting portion to the base portion, the mounting portion may be simply pushed through the “bight-line” between the backrest and cushion portions of the seat until it cooperates with the base portion and snaps into engagement between the mounting and base portions. Removal may require operation of a catch-releasing element (e.g. a push-button) of the fastening means.
In the case of a mounting means whose mounting portion is pivotable relative to the base portion, which will in general be required to be used with a seat which is able to be folded. Such seats are characteristically used as the rear seats in passenger cars of the hatchback or estate car type but also in some saloon cars, and have a seat cushion portion which can be pivoted forwardly and upwardly about an axis adjacent its lower edge relative to the vehicle structure. When the cushion has been pivoted forwardly and upwardly, the mounting portion will be able to be moved either to or from its operative position in which it extends between the back and cushion portions of the seat, after which the seat cushion can be returned to its normal position. Preferably the mounting portion is pivotable forwardly and downwardly from its operative position to its stowed position, in which latter position it is disposed beneath a rear part of the seat cushion portion.
The mounting portion preferably affords two mounting elements in the form of anchorages of the configuration and disposition specified by ISOFIX, spaced laterally of the seat, for cooperation with corresponding fastening means on a child-restraint system.
BRIEF DESCRIPTION OF THE DRAWINGS
The various advantages of the present invention will become apparent to one skilled in the art upon reading the following specification and by reference to the drawings which include:
FIG. 1 is a diagrammatic elevation of a first embodiment of the invention, shown in relation to part of a seat of a vehicle;
FIG. 2 is a diagrammatic perspective view of the device shown in FIG. 1;
FIG. 3 is a view of FIG. 1 but of a further embodiment of the invention;
FIG. 4 is a perspective view of the embodiment of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to FIGS. 1 and 2 of the drawings, there is shown a lower rear part of a vehicle seat, the seat comprising a cushion portion 10 and a backrest portion 11 . Each of these portions comprises upholstery materials disposed on a rigid frame: part of the frame of the cushion portion is indicated at 12 and part of the frame of the backrest portion at 13 . The upholstered rearmost part of the cushion portion 10 and lowermost part of the backrest portion 11 approach or touch one another, but it will be appreciated that by virtue of the resilient nature of the upholstery on each of these portions it is possible for a component to be inserted therebetween, as will be described hereafter. The cushion portion 10 may be tiltable upwardly and forwardly about an axis, not shown, adjacent its front end. In the course of such movement of the cushion portion, the frame member 12 moves in an arcuate path of movement as indicated by the line 14 . Part of a floor portion of the vehicle structure or the frame of the seat is indicated at 15 .
To provide for mounting of a child-restraint system to the seat, there is provided mounting means in the form of a base portion indicated generally at 16 and a mounting portion indicated generally at 17 . The base portion 16 includes a plate 18 which may be secured to the vehicle floor 15 by bolts as indicated at 19 , whilst a wall portion 20 is upstanding from the plate 18 in the direction towards the contacting parts of the seat cushion and backrest portions.
The mounting portion 17 extends between the adjacent parts of the seat cushion and backrest portions to engage the base portion 16 . The mounting portion 17 includes a body 22 having a slot 23 into which the wall portion 20 is closely engagable, and there is provided releasable fastening means for holding them in such engagement. Such fastening means may be similar or analogous to the fastening means commonly used in the buckles of vehicle safety belts, and include a catch member engagable with an opening 20 a in the wall portion, and spring biasing means so that when placed together in cooperating parts, the parts snap into engagement with one another and are thereafter held in engagement. The parts may be released by operation of a push-button or the like which preferably is disposed in a part 24 of the body 22 which is accessible in use above the rear of the seat cushion portion.
The body further is provided with two spaced mounting elements or anchorages each in the form of generally U-shaped metal element 25 . These are spaced and dimensioned as laid down by ISOFIX to be engagable by a child-restraint system such as a child's safety seat, to secure the latter to the seat of the vehicle. Such engagement will be by way of suitable releasable fastening means. It will be appreciated that such a child-restraint system can, but need not, be further secured to the seat of the vehicle by at least one further mounting device in addition to that illustrated.
Referring now to FIGS. 3 and 4 of the drawings, these show a further embodiment of the invention. There is a seat arranged as above described, but the mounting means for the child safety system includes a base portion 30 and mounting portion 31 which are pivotally secured to one another for angular movement about an axis 32 . The base portion 30 is fitted to the floor structure of the vehicle as above described, whilst the mounting portion 31 is able to be pivoted between the operative position (shown in full lines in FIG. 3) wherein it extends between the cushion portion and backrest portion of the seat so that mounting elements 33 are accessible, and an inoperative or stowed position (shown in broken lines in FIG. 3 ). In the latter position the part of the mounting portion 31 having the mounting elements 33 lies against the floor of the vehicle immediately beneath the rear of the seat cushion portion.
In order to move the mounting portion between such positions, the cushion portion of the seat must be pivoted forwardly and upwardly, such as indicated by the line 14 in FIG. 1, until it is clear of both the mounting portion 31 and the backrest portion of the seat. The resilience of the upholstery of the seat enables the seat cushion portion to be moved past the mounting portion 31 when the latter is in its operative position. In some vehicle seat systems, a pivotable blade-like mounting portion may be utilized in conjunction with a seat which does not fold in the manner above described.
Although the invention will usually be used in relation to a rear seat of a passenger-carrying motor vehicle, it will be appreciated that in certain circumstances it may be used in relation to a front seat of such a vehicle, or more broadly in relation to a seat of any vehicle.
The foregoing discussion discloses and describes the preferred 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 true spirit and fair scope of the invention as defined in the following claims.
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A child-restraint system is mounted in relation to a seat of a motor vehicle by a mount which includes a base portion secured to the vehicle structure and a mounting portion which extends to an accessible position upon the seat where it may be engaged by the restraint system, the mounting portion being able to be moved from its position on the seat when it is not required to be engaged by the child-restraint system.
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RELATED APPLICATION
This application claims the priority benefit of European Patent Application 12164694.7 filed on Apr. 19, 2012, the entirety of which is incorporated by reference in its entirety.
TECHNICAL FIELD
The present disclosure relates to a method for drying clothes in a household dryer having a drying chamber, at least a temperature sensor for monitoring the temperature of the exhaust air and a closed loop control system for maintaining the drying temperature close to a set point temperature.
BACKGROUND
With the term “exhaust air” we mean the air flowing from the drying chamber, i.e. in the proximity of the air outlet from such chamber. With the term “drying temperature” we mean the reference temperature for controlling the drying process, including the control of the heating element used for heating air entering the drying chamber.
A common practice is to control a tumble dryer heating element by feeding back the exhaust air temperature. The drum output temperature is usually a good approximation of the actual clothes temperature, therefore it is kept under control to avoid an excessive heating of clothes which could damage them.
The feedback is usually made through hysteresis control, i.e. the heater is switched on when the feedback temperature is below a first predefined threshold and switched on when it is above a second predefined threshold. In this way the hysteresis control shows low performance when the temperature of the heater is around the upper temperature limit and it may cause undesired oscillation of the clothes temperature.
Another more advanced way to control the heater is through a PI (proportional-integral) control and PWM (Pulse Width Modulation) control.
In the attached FIG. 1 classic control of a domestic tumble dryer is shown where the input of the control algorithm is the difference between the drum output temperature set point and its current value. The algorithm may be a simple hysteresis control or a PI control, where the output directly manages the heater actuation.
The exhaust temperature set point is fixed and for this reason the control performances are strongly dependent on the working operation conditions. Hence the time/energy performances depend on the mass of the clothes inside the dryer, the water retained by the load, the venting condition and the environment condition.
SUMMARY
An object of the present disclosure is to provide a control method which overcomes the above drawbacks and which can provide shorter drying cycles and energy savings.
Such objects are reached according to methods and dryers having the features listed in the appended claims.
According to the disclosure, an adaptive temperature control selects the set point around the optimum value in terms of energy consumption, drying time and fabric care avoiding at the same time a wide temperature swinging and clothes temperature rising close to the end of the cycle is described.
According to a first embodiment, when a certain time has elapsed from the cycle start, the set point temperature value is set substantially equal to the current drum exhaust temperature. The time threshold may be a constant or a linear combination of other variables such as drying cycle selected by the user, the load mass and the environment temperature.
According to a second embodiment, when exhaust temperature derivative goes below a certain threshold, the set point temperature value is set substantially equal to the current drum exhaust temperature. During the drying cycle, after a first warm up phase where sensible heat is principally transferred to the load with a low evaporation coefficient, in the steady state phase the evaporation starts to be important and at the same time the quantity of sensible heat transferred to the load decreases due to its temperature increasing. Therefore the exhaust temperature derivative is a good estimator of when the steady state condition is reached.
According to a third embodiment, the optimum temperature set point may be also computed making use of the information given by a simplified thermodynamic model of the dryer system. The model may have several input signals and use output values to establish the optimum temperature set point. The input signals to the dryer model can be air temperatures, air humidity and status of the dryer components, such as heating element. The output values used for calculating the optimum set point may be airflow rate, load mass and the residual moisture content of load. Knowing these parameters the set point that optimizes the drying cycle in that predicted condition is then estimated.
BRIEF DESCRIPTION OF THE FIGURES
Further advantages and features of the present disclosure will become clear from the following detailed description, with reference to the attached drawings in which:
FIG. 1 is a block diagram showing a prior-art way of controlling the drum output temperature of a clothes tumble dryer;
FIG. 2 is a schematic view of an air-vented dryer in which a method according to the disclosure is implemented;
FIG. 3 is a diagram showing how a method according to a first embodiment is carried out;
FIG. 4 is a diagram showing how a method according to a second embodiment is carried out;
FIG. 5 is a block diagram showing an adaptive temperature control architecture used in a third embodiment; and
FIG. 6 is a diagram showing how a method according to the third embodiment is carried out.
DETAILED DESCRIPTION
With reference to the drawings, and particularly to FIG. 2 , a tumble dryer D comprises a rotating drum 1 actuated by an electric motor 6 containing a certain amount of articles, a screen 2 that collects the lint detaching from the tumbling clothes, an air channel 3 that conveys the air to a vent 7 , a heating element 4 that heats the air going into the drum D (resistance, heat pump, etc. . . . ), a temperature sensor 5 a that measures the temperature of the drum exhaust air and a temperature sensor 5 b measuring the temperature of the heating circuit, i.e. downstream from the heating element 4 . All the sensors and components of the dryer D are connected to a central control unit (not shown) which receives signals from the sensors and drives components according to different drying programs selected by the user and stored therein.
The disclosure is mainly focused on methods to adapt the temperature set point close to the optimum value in terms of energy consumption, drying time and fabric care avoiding wide temperature swings and temperature rising close to the end of the cycle.
The adaptive temperature control chooses the optimum set point according to the value of the exhaust drum temperatures when the system reach the steady state condition, which may be evaluated in different ways.
According to a first embodiment and with reference to FIG. 3 , when a certain time threshold t thr from the cycle start is reached, the set point value ST is set equal to the current drum exhaust temperature E. In FIG. 3 , the inlet drum temperature K is also shown.
The time threshold may be a constant predetermined value or a linear combination of other variables such as the type of drying cycle selected by the user, the load mass and the environment temperature, as in the following formula:
t thr =a+b 1 ·cycle+ b 2 ·mass+ b 3 ·T amb
In the above formula, for an air vented dryer modified according to the present disclosure, the following are example constant values:
a=150
b 1 =1
b 2 =100
b 3 =−2
with the following parameters of the drying cycle:
cycle=0
mass=4 (kg)
T amb =25(° C.)
Similar constants may be found for a different platform (e.g., a condenser dryer, a heat pump dryer, a hybrid heat pump, etc.),
According to a second embodiment shown in FIG. 4 , when an exhaust temperature derivative ED goes below a certain threshold, the set point temperature value ST is set equal or close to the current drum exhaust temperature E. As shown in FIG. 4 , after a first warm up phase where sensible heat is principally transferred to the load with a low evaporation coefficient, in the subsequent steady state phase the evaporation starts to be important and at the same time the quantity of sensible heat transferred to the load decreases hence its temperature increases. Therefore the exhaust temperature derivative ED is a good estimator of the steady state condition. In FIG. 4 the same references of FIG. 3 are used, i.e. K for inlet drum temperature, ST for set temperature value, E for the exhaust temperature. In FIG. 4 the reference F indicates the flag for the steady state.
FIG. 4 illustrates a test carried out on an air vented dryer modified according to the present disclosure; similar results may be obtained with a different platform (e.g., a condenser dryer, a heat pump dryer, a hybrid heat pump, etc.), in which the exhaust derivative is computed as:
T . exh = T exh ( t - 1 ) - T exh ( t ) clock ( t - 1 ) - clock ( t )
The quantity {dot over (T)} exh is then filtered with an IIR filter initialized at 100° C./s, obtaining {dot over (T)} exh _ filt . When the value of {dot over (T)} exh _ filt is less than 0.2° C./s the exhaust set point value ST is adapted from the initial value to the actual exhaust temperature E rounded at the closest integer, in the example from 60° C. to 51° C.
FIGS. 5 and 6 relate to a third embodiment in which the optimum set point is computed making use of the information given by a simplified model of the dryer system. The information can be respectively humidity, load conductivity or residual moisture content estimated (RMC). The temperature set point ST is placed equal to the exhaust temperature E when the chosen parameters go below a predetermined threshold. Further system information may provide boundaries in the set point selection such as airflow and/or load mass.
In the methods described above, the choice of temperature set point ST is restricted to a range defined by lower and upper boundaries to avoid wrong estimation that may lead to extended cycle duration or fabric damage.
In the example shown in FIGS. 5 and 6 , during the first part of the cycle the fabric load mass and the airflow of the system are estimated. According to those values, the minimum and maximum set point threshold are calculated by means of the following equation, rounded to the next integer value:
Setpoint min =α*airflow+β*LoadMass+γ
Setpoint max =Setpoint min +Δ
where example constants are:
α=−750
β=−0.5
γ=60
Δ=10
and the estimated variables are:
airflow=0.0237 kg/s
LoadMass=4.4662 kg
Hence:
Setpoint min =40° C.
Setpoint max =50° C.
Then the set point value ST is set equal to the exhaust temperature E when the estimated residual moisture content RMC goes below a predetermined value, according to the set point min max boundaries (respectively indicated with references M and L in FIG. 6 ). If in the time period before reaching this condition the exhaust temperature goes above the Setpoint max , Setpoint max is set as setpoint ST.
FIG. 6 illustrates a test carried out on an air vented dryer modified according to the present disclosure, the chosen RMC threshold is equal to 40% of starting RMC and the set point goes from the initial default value of 55° C. to 42.43° C.; similar behavior may be obtained with a different platform (e.g., a condenser dryer, a heat pump dryer, a hybrid heat pump, etc.).
The selection of the appropriate temperature set point ST is important and it is one of the drivers of energy consumption and fabric care. By selecting a low set point ST the cycle time is stretched out; on the other hand a high set point ST may be not reached or reached just at the end of the drying cycle, therefore over-heating the fabric when is almost dried.
Without the adaptive temperature set point according to this disclosure, there can be the selection of the wrong set point which causes an increase of the drum exhaust temperature E that means heat losses.
Even though the methods and the dryers according to the present disclosure have been described with reference to an air-vented dryer, the same methods can be used also for heat-pump dryers and condenser dryers as well.
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A method for drying clothes in a household dryer having a drying chamber, a temperature sensor for monitoring temperature an air exhaust temperature from the chamber, and a control system for maintaining a temperature in the drying chamber close to a set point temperature by selecting the set point temperature based on the air exhaust temperature.
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“This application is a continuation of U.S. application Ser. No. 10/375,227 filed on Feb. 27, 2003.”
FIELD OF THE INVENTION
This invention relates to securely transmitting data, and more particularly to achieving improved protection against the breaching of security even when data is sent over a channel subject to interception.
BACKGROUND OF THE INVENTION
The securing of data during transmission has been of interest throughout human history. Secure communication has been an essential part of commerce since time immemorial.
More recently, and especially since the widespread availability of computing power and technical means of data transmission, with sophisticated means of securing data transmitted over telecommunications channels and equally sophisticated technical means of decrypting messages, there has developed a rapidly-accelerating race between those who wish to secure messages and those who wish to “crack” them.
There is a constant search for new technical means of securing data during transmission by increasing the threshold of feasibility of decryption, and an equally constant search for means of rendering feasible decryptions that were thought to be infeasible. Similarly, the processing and transmission costs of sending information securely are of concern. The volume of data to be transmitted in the course of business transactions is increasing, and the cost of using public networks is constantly decreasing, while the cost of using private networks is ever more costly. It would be advantageous to be able to send more data, especially in bulk data applications, over less costly open channels, such as the Internet, but it is difficult to secure transmissions over such a medium to the standard normally required for commercial confidentiality purposes.
There have been attempts to alleviate the problem of combining security with low cost.
Published European patent application number EP 0 993 142 A1, for example, proposes a method for providing security for data wherein the bulk of transmitted data is encrypted and transmitted over an inherently less secure channel while selected segments of data are transmitted over a normally private channel, such as the telephone network. An eavesdropper on the less secure channel is thus prevented from reading all the data. Disclosed also is the notion of using one or more scrambling algorithms to scramble data according to a formula derived from the data itself.
Published PCT patent application number WO 00/18078 proposes a method whereby a message is split and transmitted over two channels in such a manner that the portion of the message to be sent over the less secure channel is encrypted, while the portion transmitted over the secure channel remains unencrypted.
It is desirable to find a way of further increasing the security of a message by reducing the computational feasibility of an unauthorized person's recovering the information content of the message and reducing the cost of processing and transmission.
SUMMARY OF THE INVENTION
The present invention accordingly provides, in a first aspect, a method for securely transmitting data comprising the steps of adaptively transforming said data using a data position-dependent adaptive transformation technique; breaking said data into segments; transmitting one or more segments of said data over a first transmission channel; and transmitting one or more segments of said data over a second transmission channel.
The method of the first aspect preferably further comprises the step of rearranging the sequence in which said one or more segments are transmitted over said second transmission channel.
Preferably, said first channel is a secure channel and said second channel is an insecure channel, and a greater number of said segments is transmitted over said insecure channel than is transmitted over said insecure channel.
Preferably, said data position-dependent adaptive transformation technique is an adaptive compression technique.
The method of the first aspect further comprises the steps of receiving said one or more segments from said first and said second transmission channels; resequencing said one or more segments; performing an adaptive inverse transformation on said segments to recover an original information content; and outputting said original information content.
In a second aspect, the present invention provides an apparatus for securely transmitting data comprising a data position-dependent adaptive transformer for adaptively transforming said data; a splitter for breaking said data into segments; a transmitter for transmitting one or more segments of said data over a first transmission channel; and a transmitter for transmitting one or more segments of said data over a second transmission channel.
The apparatus of the second aspect preferably further comprises a desequencer for rearranging the sequence in which said one or more segments are transmitted over said second transmission channel.
Preferably, said first channel is a secure channel and said second channel is an insecure channel, and wherein a greater number of said segments is transmitted over said insecure channel than is transmitted over said insecure channel.
Preferably, said data position-dependent adaptive transformation technique is an adaptive compression technique.
Preferably, the apparatus further comprises a receiver for receiving signals from said first and said second channels; a resequencer for resequencing said signals; a position-dependent adaptive inverse transformer for transforming said signals; and an output for outputting information content.
In a third aspect, the present invention provides a computer program product tangibly embodied in a storage medium to, when loaded into a computer system and executed, securely transmit data, said computer program product comprising computer program code means to adaptively transform said data using a data position-dependent adaptive transformation technique; computer program code means to break said data into segments; computer program code means to transmit one or more segments of said data over a first transmission channel; and computer program code means to transmit one or more segments of said data over a second transmission channel.
The computer program product of the third aspect preferably further comprises computer program code means to rearrange the sequence in which said one or more segments are transmitted over said second transmission channel.
In a fourth aspect, the present invention provides a method for receiving securely transmitted data previously encoded and transmitted by a method comprising the steps of adaptively transforming said data using a data position-dependent adaptive transformation technique; breaking said data into segments; transmitting one or more segments of said data over a first transmission channel; and transmitting one or more segments of said data over a second transmission channel.
In a fifth aspects the present invention provides a method for receiving securely transmitted data previously encoded and transmitted by at least one of an apparatus and a computer program product comprising a data position-dependent adaptive transformer for adaptively transforming said data; a splitter for breaking said data into segments; a transmitter for transmitting one or more segments of said data over a first transmission channel; and a transmitter for transmitting one or more segments of said data over a second transmission channel.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention will now be described by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a process flow diagram representing a method of a presently preferred embodiment of the present invention. FIG. 1 also illustrates the computer program code steps required to implement a presently preferred embodiment of the present invention in a computer program product.
FIG. 2 is a block-level device diagram illustrating an apparatus in accordance with a presently preferred embodiment of the present invention in hardware.
FIG. 3 is a process flow diagram representing a preferred further feature of the present invention to incorporate an information recovery method FIG. 1 also illustrates the computer program code steps required to implement the preferred feature in a computer program product.
FIG. 4 is a block-level device diagram illustrating an apparatus embodying a preferred feature of the present invention in hardware.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to FIG. 1 , there are shown the steps of a method according to a presently preferred embodiment. FIG. 1 also illustrates the computer program code steps required to implement a presently preferred embodiment of the present invention in a computer program product, but for brevity, the method steps will be described here. It will be clear to those skilled in the programming art that the method lends itself to embodiment in program code means implementing each of the logical method steps.
The method begins at START step 100 , and the data to be transmitted is received at an input 102 . The data is then subjected to an adaptive transform technique at step 104 . It is presently most preferred that the technique be a form of adaptive compression, for example, Lempel-Ziv compression, adaptive Huffman compression, adaptive arithmetic encoding or the like. These compression methods are well-known in the art, and will not be further described, except to point out that they have a characteristic in common, in that all the data in the compressed datastream is position-dependent. That is, a particular pattern of bits at one point in the datastream may mean one thing, and at a “later” point in the data stream may mean something different. There is a backward dependency that becomes greater as the length of the datastream grows. A further characteristic is that these methods may use variable-length tokens to represent variable lengths of cleartext. Particularly advantageously, adaptive dictionary Lempel-ziv compression depends on the existence of an agreed notional base dictionary of primitives on which the full adaptive dictionary is adaptively built as a data stream is compressed. Unless the interceptor of a data signal knows what that base dictionary is, there is an initial difficulty in understanding how to interpret the data to recover information content.
For example, in variable length adaptive dictionary Lempel-Ziv encoding, a 9-bit sequence may be used for the first 4096 tokens representing references into a notional dictionary, and then a signal may be attached to the datastream to indicate a “change-up” to 10-bit tokens for the next 4096 tokens. These two characteristics are observed to be a drawback in circumstances in which the channel of transmission may be broken, for example in mobile telephony, where a receiver may pass under a train tunnel, or into other “dead ground” where the signal breaks down. If a transmission is underway, because the presently transmitted data has a backward dependency on the earlier data, the receiver becomes unable to continue decompressing the datastream. Continuity having been broken, the receiver does not know what the tokens now being received represent, nor even, possibly, how long they now are.
This drawback, however, may be exploited in circumstances in which the transmitter wishes to prevent a receiver from being able to reconstruct the datastream, as is the case in providing security of transmission, when the data needs to be secured against an eavesdropping receiver. The presently most preferred embodiment of the invention takes advantage of this characteristic of adaptive compression. In an alternative, other forms of adaptive transformation, such as adaptive (or “rolling”) encryption may be used instead of adaptive compression. The use of adaptive compression as part of the means of securing the data has the advantage over encryption that the data is simultaneously compressed and secured, thereby saving processing time and cost and transmission time and cost.
Returning to FIG. 1 , the head segment of the adaptively transformed data is now sent over the secure channel at step 106 . The use of head functions in programming languages to operate on data taken from the beginning of a sequence of data is well-known to those skilled in the art and need not be explained further here. The length of head data that is sent can be optimized depending on data type, amount of repetition and inherent predictability. It is preferred, for example, to transmit, in the case of the Lempel-Ziv exemplary embodiment, the header information and some portion of the first 4096 tokens, such that the eavesdropper is unaware of the start position of the datastream relative to the beginning of the notional dictionary.
At step 10 S, the adaptively-transformed data is now split into segments determined by clock or counter functions primed by a pseudorandom number generator function. The pseudorandom number generator function should be constrained to provide an output lying between a determined clock or counter minimum and a corresponding maximum to give bursts of data of varying lengths. The function may also advantageously be biased to preferentially select shorter generated lengths for the data that is subsequently to be transmitted over the conventionally more expensive secure channel.
A first counter or clock (hereafter referred to as Counter 1 ) is set at step 110 , based on the output from the pseudorandom number generator function, and at step 112 a segment of tail data is transmitted over the insecure channel until either an end-of-data condition is signalled 114 , or Counter 1 reaches its threshold and “flips” at step 116 . The tail function is a well-known programming language function, like head, but which operates on data from the remainder of a sequence after a head operation. If the end-of-data has not yet been reached, and Counter 1 has flipped, a counter or clock (hereafter referred to as Counter 2 ) is set at step 118 . The next segment of tail data is transmitted over the secure channel at step 120 until either an end-of-data condition is signalled at step 122 , or Counter 2 flips at step 124 . If Counter 2 has flipped at step 124 , control returns to step 110 where Counter 1 is set and the process from steps 110 iterates until end of data is signalled at either step 114 or step 122 , when the process reaches END step 128 .
Turning now to FIG. 2 , there is shown a block-level device diagram illustrating an apparatus in accordance with a presently preferred embodiment of the present invention in hardware.
FIG. 2 shows an apparatus 200 with input DATA_IN to an adaptive transform device 204 . Adaptive transform device 204 may be a hardware Lempel-Ziv encoder device in a presently most preferred embodiment. In an alternative it may be, for example a device for performing any other adaptive transform, such as adaptive compression by other means or adaptive encryption, as described above. Adaptive transform device 204 is operatively connected to splitter 206 , which may be any of the well-known signal splitting devices available commercially.
Splitter 206 receives sequential data signals from the output of adaptive transform device 204 and splits them between its two or more outputs. The output path from splitter 206 is under the control of a switching device 208 , comprising a constrained pseudorandom number generator 210 .
The concept of constraints on pseudorandom numbers for various purposes is well-known in the art. One implementation of such a generator is to have a normal pseudorandom number generator having an output in its normal arithmetic converted to a number in a modular arithmetic system.
Generator 210 is in turn operatively connected to counter device 212 which may be a clock device in an alternative embodiment. The function of counter device 212 is to count or time the transmissions over each of the secure and insecure channels and to operate flip-flop switch 214 .
Flip-flop switch 204 in turn operates to gate the signals on the outputs of splitter 206 according to the counts or times controlled by counter device 212 .
The outputs from splitter 206 are thus channelled to desequencer 216 via one or the other of the outputs of splitter 206 . Desequencer 216 operates to rearrange the order in which the data segments are to be transmitted and to ensure that the sequencing “header” information required to reassemble the entire data transmission at the receiver end is selected to be transmitted over the secure channel.
The signal from desequencer 216 is now passed down one of the two outputs of desequencer 216 to transmission port 218 where each data segment is prepared for transmission and transmitted over either secure channel 220 at output DATA_OUT_ 1 or insecure channel 222 at output DATA_OUT_ 2 .
In this manner, the preferred embodiment of the present invention reduces the computational feasibility of an unauthorized person's deriving information content from an intercepted signal. The unauthorized person is hindered by not knowing the true sequence and the start point of the data being signalled, nor the meaning and lengths of the tokens in the signal.
It will be appreciated that the method described above will typically be carried out in software running on a processor (not shown), and that the software may be provided as a computer program product carried on any suitable data carrier (also not shown) such as a magnetic or optical computer disc.
Turning now to FIG. 3 , there is shown a process flow diagram representing a preferred further feature of the present invention to incorporate an information recovery method. FIG. 3 also illustrates the computer program code steps required to implement the preferred feature in a computer program product.
The flow begins at START 300 , and a step 302 , data is received from the secure and insecure channels. It is necessary to understand the original sequence of segments as transmitted, and to this end, at step 304 the method includes a step of reading sequence data from the header that was preferentially transmitted with some early data over the secure channel. At step 306 , the data is recombined in sequence based on the sequence data from the header. The data is then in condition to be inversely transformed using a position-dependent adaptive transformation technique. Essentially this is the mirror of the original transformation as, for example is the case with the Lempel-Ziv compression algorithm, as used in a presently preferred embodiment of the present invention. At step 310 , the information content is output, and the method ends at END 312 .
FIG. 4 shows a block-level device diagram illustrating an apparatus embodying the preferred receiver feature of the present invention in hardware.
In FIG. 4 is shown receiver apparatus 400 . Inputs DATA_IN_ 1 and DATA_IN_ 2 are received at reception port 418 from channels 420 and 422 , Reception port 418 passes the data signals to resequencer 416 which recovers the sequence data from the header information received from the secure channel and resequences the data segments ready for the signals from the two channels to be combined by combiner 406 . Combiner 406 passes the recombined data signal to adaptive transform device 404 , which performs an inverse adaptive transform to recover the original information content and output it at DATA_OUT.
It will be appreciated that the method described above will typically be carried out in software running on a processor (not shown), and that the software may be provided as a computer program element carried on any suitable data carrier (also not shown) such as a magnetic or optical computer disc. The channels for the transmission of data likewise may include storage media of all descriptions as well as signal carrying media, such as wired or wireless signal media.
While the exemplary embodiment has been described in terms of a data signal being transmitted over a medium, it will be appreciated by one of ordinary skill in the art that the data may also be held as a static entity, in for example, one or more World Wide Web pages on the Internet, from which it may be retrieved by conventional browser means before being processed according to the method or by the apparatus or computer program product of the preferred embodiment of the invention.
The present invention may suitably be embodied as a computer program product for use with a computer system. Such an implementation may comprise a series of computer readable instructions either fixed on a tangible medium, such as a computer readable medium, e.g., diskette, CD-ROM, ROM, or hard disk, or transmittable to a computer system, via a modem or other interface device, over either a tangible medium, including but not limited to optical or analogue communications lines, or intangibly using wireless techniques, including but not limited to microwave, infrared or other transmission techniques. The series of computer readable instructions embodies all or part of the functionality previously described herein.
Those skilled in the art will appreciate that such computer readable instructions can be written in a number of programming languages for use with many computer architectures or operating systems. Further, such instructions may be stored using any memory technology, present or future, including but not limited to, semiconductor, magnetic, or optical, or transmitted using any communications technology, present or future, including but not limited to optical, infrared, or microwave. It is contemplated that such a computer program product may be distributed as a removable medium with accompanying printed or electronic documentation, e.g., shrink wrapped software, pre-loaded with a computer system, e.g., on a system ROM or fixed disk, or distributed from a server or electronic bulletin board over a network, e.g., the Internet or world Wide Web.
It will be appreciated that various modifications to the embodiment described above will be apparent to a person of ordinary skill in the art. For example, any data that is either transmitted or statically held for retrieval may be treated by further methods of obfuscation, such as encryption methods or steganographic, or data-hiding, methods, to render the problem faced by an interceptor further lacking in tractability.
In this manner, the preferred embodiment of the present invention reduces the computational feasibility of an unauthorized person's deriving information content from an intercepted signal. The unauthorized person is hindered by not knowing the true sequence and the start point of the data being signalled, nor the meaning and lengths of the tokens in the signal.
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A method, apparatus and computer program product for transmitting data secures the data by adaptively transforming it and spreading the transformed data piecewise over plural transmission channels. The method, apparatus and computer program product may select low-cost channels preferentially to transmit greater amounts of the data; may disorder the data and transmit ordering information separately over a preferred channel of higher security; may conceal data in a lower-security channel by steganographic methods; and may conceal the sequence of the data by placing segments of it statically, for example, in a WWW website, while providing sequencing data on the preferred channel of higher security. A receiving method, apparatus and computer program product may also be provided for recovering information content from signals on the plural channels.
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This application is a continuation of application Ser. No. 08/149,271 filed Nov. 9, 1993, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a misfire detection system for an internal combustion engine, and more particularly to such a system in which misfire detection is inactivated under specified operating conditions.
2. Description of the Prior Art
The cause for misfiring in an internal combustion engine may be related to either the fuel supply system or the ignition system of the engine. The assignee previously proposed a system for detecting misfire caused by the fuel supply system (Japanese Laid-Open Patent Publication No. 5(1993)-65866) and a system designed to improve misfire detection accuracy by prohibiting the making of misfire detections when engine combustion is apt to become unstable, as when the fuel injection system controls the air/fuel to be lean, or when the fuel supply is being cut (Japanese Laid-Open Patent Publication No. 5(1993)-164033) .
In a vehicle equipped with an automatic transmission, the engine output is sometimes deliberately reduced, such as by retarding the ignition timing, by making the air/fuel ratio lean or by cutting off the fuel supply, in order to reduce the shock the passengers feel during gear ratio shifting. Similar engine output reduction control is also conducted for mitigating swaying oscillation of the propeller shaft or the like caused by output transmission lag. Since combustion becomes unstable during control of this kind, the probability of erroneous misfire detection is high. This degrades the reliability of the misfire detection system.
SUMMARY OF THE INVENTION
This invention was accomplished in light of the foregoing circumstances and has as its object to provide a misfire detection system for an internal combustion engine which deactivates misfire detection under specified operating conditions deliberately implemented for reducing engine output, thereby improving misfire detection accuracy and enhancing the misfire detection system's reliability.
For realizing the object, the present invention provides a system for detecting misfire for an internal combustion engine, comprising, a first device for detecting whether misfire has occurred in the engine, a second device for detecting a specific engine operating condition in which a vehicle on which the engine is mounted is to be degraded in its running performance, a third device for adjusting a command value which reduces output of the engine when the specific engine operating condition is detected, and a fourth device for inactivating the operation of the first device when the third device adjusts the command value.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will be more apparent from the following description and drawings, in which:
FIG. 1 is a schematic view showing the overall configuration of the misfire detection system for an internal combustion engine according to the invention;
FIG. 2 is a schematic view showing the overall configuration of the misfire detection circuit illustrated in FIG. 1;
FIG. 3 is a timing chart showing the operation of the misfire detection circuit illustrated in FIG. 2;
FIG. 4 is a flowchart showing the operation of the misfire detection system according to the invention;
FIG. 5 is a flowchart showing a subroutine for determining a misfire detection prohibitive condition referred to in the flowchart of FIG. 4;
FIG. 6 is a flowchart, similar to FIG. 5, but showing another subroutine of determining a misfire detection prohibitive condition referred to in the flowchart of FIG. 4 according to a second embodiment of the invention;
FIG. 7 is a flowchart, similar to FIG. 4, but showing the operation of the misfire detection system according to a third embodiment of the invention;
FIG. 8 is a timing chart, similar to a portion of FIG. 3, but showing the operation of the misfire detection system according to a fourth embodiment of the invention;
FIG. 9 is a timing chart, similar to a portion of FIG. 3, but showing the operation of the misfire detection system according to a fifth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention will now be explained with reference to the drawings.
The overall configuration of the misfire detection system for internal combustion engines according to the invention is shown schematically in FIG. 1. A throttle valve 14 is provided in an intake manifold 12 of, for example, a four cylinder engine 10. The throttle valve 14 has a throttle position sensor 16 associated therewith for outputting an electric signal representing the amount of opening of the throttle θTH to an electronic control unit, hereinafter referred to as ECU, 18.
For each cylinder, a fuel injection valve 20 is provided in the intake manifold 12 between the engine 10 and the throttle valve 14 at a point immediately upstream of an intake valve (not shown). Each fuel injection valve 20 is supplied with fuel from a fuel tank 22 via a fuel pump etc. (not shown) and is also electrically connected with the ECU 18, which supplies it with a drive signal for controlling its open time (injection time) TOUT. Spark plugs 24 associated with the respective cylinders of the engine 10 are electrically connected through an ignition distributor 26 with the ECU 18 which controls their ignition timing θIG. The lines connecting the spark plugs 24 and the ignition distributor 26 have ignition voltage sensors 28 capacitively coupled therewith so as to form multi-pF capacitors with the lines. The detection signals produced by the ignition voltage sensors 28 are forwarded to the ECU 18.
The output of a manifold absolute pressure sensor 32 installed immediately downstream of the throttle valve 14 is converted to an electric signal indicative of manifold absolute pressure PBA that is forwarded to the ECU 18. An intake air temperature sensor 34 is installed down-stream of the manifold absolute pressure sensor 32 for detecting the intake air temperature TA and outputting a corresponding signal to the ECU 18.
An engine coolant temperature sensor 36 is installed in a cooling water passage (not shown) of the engine 10 for detecting the engine coolant temperature TW and outputting a corresponding signal to the ECU 18. In addition, a crankshaft sensor 38 and a camshaft position sensor 40 are installed in the vicinity of the crankshaft and camshaft (neither shown), for outputting a pulse signal θCR or CYL to the ECU 18 once every prescribed crank angle, respectively. The ECU 18 calculates the engine speed from the number of pulse signals θCR output by the crankshaft sensor and identifies from the output of the camshaft position sensor which cylinder is at a predetermined crank angular position.
The engine 10 is provided with an exhaust pipe 42 which in turn is equipped with a three-way catalytic converter 44 for purifying the exhaust gas and, upstream of the three-way catalytic converter 44, with an oxygen concentration sensor 46 for sending to the ECU 18 an output proportional to the oxygen concentration O 2 of the exhaust gas. The fuel tank 22 is equipped with a fuel temperature sensor 50 for detecting the fuel temperature TF and with a tank pressure sensor 52 for detecting the in-fuel tank pressure PT, the outputs of which are sent to the ECU 18.
The ECU 18, which is constituted as a microcomputer comprising an input circuit 18a for shaping, voltage level adjusting and A/D converting input signals, a CPU 18b, a memory 18c, and an output circuit 18d. The ECU 18 controls the fuel injection time TOUT and the ignition timing θIG in accordance with the operating conditions ascertained from the sensor detection values. It also determines the occurrence of misfire on the basis of input received from a misfire detection circuit 30.
A power transmission unit 60 equipped with an automatic transmission is connected to the engine 10 for converting the engine output and transmitting it to driven wheels 66 via a propeller shaft 62 and a differential 64. The power transmission unit 60 is equipped with another ECU 68 for shift control. The ECU 68 selects the gear ratio (gear position) on the basis of the vehicle speed, the throttle opening and the like, and operates a hydraulic control circuit 70 for shifting the automatic transmission to the selected gear ratio. The shift-control ECU 68 is constituted similarly to the ECU 18 and the two ECUs are able to communicate with each other via a signal line.
The configuration of the misfire detection circuit 30 is illustrated in detail in the block diagram of FIG. 2. A terminal T1 supplied with power source voltage VB is connected with an ignition coil 78 consisting of a primary coil 74 and a secondary coil 76. The primary coil 74 is connected with the ECU 18 through a transistor 80 and a drive circuit 82, while the secondary coil 76 is connected with the center terminal of each spark plug 24 through a diode 84 and the ignition distributor 26. At each cylinder, the ignition voltage sensor 28 mentioned above is connected with an input circuit 86 through a terminal T2, and the output of the input circuit 86 is forwarded to a peak-hold circuit 88 and the non-inverting input terminal of a comparator 90. The output of the peak-hold circuit 88 is applied to the inverting input terminal of the comparator 90 through a comparison level setting circuit 92 which produces and sends a reference value VCOMP to the terminal. The reset input terminal of the peak-hold circuit 88 is connected with the ECU 18. The output of the comparator 90 is sent to the ECU 18 through a terminal T4 and a gate circuit 94. The gate circuit 94 receives a gate signal from the ECU 18.
The operation of the misfire detection circuit 30 will be briefly explained with reference to FIG. 3. In FIG. 3, (a) indicates ignition command signal A, (b) indicates gate signal G, (c) through (e) indicate the case where combustion occurs (misfire does not occur), and (f) through (h) indicate the case where combustion does not occur (misfire occurs). After an ignition command signal A has been issued at time t0, a voltage of a level not high enough to cause spark discharge is applied between the terminals of the spark plug 24 during a time T2. When misfire occurs due to a problem in the fuel supply system, the air-fuel mixture does not ionize, creating a resistance between the spark plug electrodes larger than when the air-fuel mixture's ionization does occur. As a result, the detection value of the ignition voltage sensor is higher than when combustion occurs. Therefore, if a value (marked as C or C' in the figure), equal to about 2/3 of the peak value of the ignition voltage (marked as B or B') is set in the comparison level setting circuit as the reference value VCOMP for comparison with the sensor detection value B, B', the width of the output pulse CP of the comparator 90 (shown at (g)), will be larger than in the case where combustion occurs (shown at (d)). If the width of the pulse CP is integrated over the gate interval TG (from time t3 to time t4), as illustrated at (e) or (h) in the figure, and compared with another reference value CPREF, it is possible to detect whether or not combustion occurred; i.e., to detect whether or not misfire occurred. This detection is explained in detail in the assignee's Japanese Laid-Open Patent Publication 5(1993)-164033.
Based on the foregoing, an explanation of the operation of the misfire detection system of the invention will now be explained with reference to the flowchart of FIG. 4. This subroutine is activated at every TDC (top dead center).
First, in S10, a check is made as to whether or not a condition prohibiting misfire detection is in effect. This subroutine is explained in FIG. 5, after which the remainder of the flowchart in FIG. 4 will be explained.
FIG. 5 is the flowchart of a subroutine for checking whether or not such a prohibitive condition is in effect. In S100 a check is made to determine whether or not the aforementioned engine output control for reducing the shock passengers feel during gear change is being conducted. In this control the ECU 18 uses gear change information received from the shift-control ECU 68 as the basis for intentionally lowering the engine output when the transmission is being shifted so as to moderate the shock the passengers feel during gear shifting. The engine output may be lowered by, for example, retarding the ignition timing, making the air/fuel ratio lean, or cutting off the supply of fuel. However, since this control is not directly related to the gist of this invention, it will not be described in detail here. Further description can be found in, for example, the assignee's Japanese Laid-Open Patent Publication 1(1989)-178736, Japanese Laid-Open Patent Publication 1(1989)-178740 and Japanese Laid-Open Utility Model Publication 3(1991)-45434, which propose systems for control of this type.
When it is found in S100 that the control is in progress, the program passes to S102 in which a down count timer is set to a predetermined value and started and to S104 in which it is determined that a prohibitive condition is in effect. If the result in S100 is negative, the program passes to S106 in which a check is made as to whether or not the timer value has reached zero, and if it has not, to S104 in which it is determined that a prohibitive condition is in effect, and if it has, to S108 in which it is determined that a prohibitive condition is not in effect. The reason for maintaining the determination that a prohibitive condition is in effect for a predetermined time after the engine output reduction control has been terminated is that it takes a little time for the combustion to stabilize after the control is stopped. The period of time set in S102 is therefore that required for the combustion to stabilize following control termination.
Returning to FIG. 4, when it is decided in S10 of the flowchart of FIG. 4 that no prohibitive condition is in effect, the program passes to S12 where a check is made as to whether or not a flag IG (which, being set to 1 by a separate subroutine simultaneously with the issuance of an ignition command signal, indicates the aforesaid time t0) is set to 1, and if it is, to S14 in which a check is made as to whether or not the time tR (explained later) clocked by a reset timer is less than a prescribed time tRESET, and if it is, to S16 in which a check is made as to whether or not a pulse (the output pulse CP of the comparator 90) is present. If the pulse is found to be present in S16, the program passes to S18 in which a counter CP for counting up the number of pulses is incremented. (This corresponds to the pulse integration mentioned above.) The program then passes to S20 in which the integrated value is compared with the reference value CPREF. If the integrated value is larger than the reference value CPREF, the program passes to S22 in which it is determined that misfire occurred, and if it is not, the program passes to S24 in which it is determined that misfire did not occur (combustion did occur).
If it is found in S10 that a prohibitive condition is in effect, the routine is immediately terminated. On the other hand, if the result in S12 is negative, the program passes to step S26 in which the time tR of the reset timer is initialized to zero. The time tR clocked by the reset timer and the prescribed time tRESET are for determining the reset timing of the peak-hold circuit 88. Specifically, when the clocked time tR becomes equal to the prescribed time tRESET, the peak-hold value is reset. Therefore, when it is found in S14 that the clocked time tR is equal to or greater than the prescribed time tRESET, the program passes to S28 in which the counter CP is set to zero, to S30 in which the flag IG is set to zero, and to S24 in which it is determined that misfire did not occur (combustion did occur).
In the embodiment under discussion, since misfire detection is not conducted when control is being conducted to deliberately reduce engine output for avoiding gear change shock, there is no danger of erroneous misfire detection. More specifically, the detection is not conducted during the control because the unstable combustion at such times increases the likelihood of detection error and hence the likelihood of the fuel supply system being misjudged to be malfunction. As a result, misfire detection is conducted only during operating conditions that involve little chance of detection error, whereby the detection accuracy is increased and the reliability of the misfire detection system enhanced.
A second embodiment of the invention is shown in FIG. 6, which is the flowchart of another prohibitive condition discrimination subroutine. In S200 of this second embodiment it is checked if engine output reduction control is being conducted for preventing swaying oscillation of the propeller shaft 62 and the like. Control of this type is conducted so that the vehicle passengers will not experience the torsional vibration that occurs in the shaft etc. during vehicle acceleration because of the time delay in transmitting the increased engine output to the power transmission unit. Whether or not the vehicle is accelerating is determined from the change in air intake manifold absolute pressure PBA or the throttle valve opening θTH. As this is explained, for example, in the assignee's Japanese Laid-Open Patent Publication 4(1992)-109075 and Japanese Laid-Open Utility Model Publication 3(1991)-45475, it will not be discussed further here. The remainder of the procedure, including steps S202 to S208, is the same in nature and effect as the corresponding part of the first embodiment.
FIG. 7 is a flowchart similar to that of FIG. 4 relating to a third embodiment of the invention. In the third embodiment, after misfire detection is conducted in S308 and S310, the program passes to S312 in which a decision is made as to whether a prohibitive condition is in effect, and if the result of the decision is affirmative, to S314 in which it is determined that misfire did not occur (combustion did occur). The effect achieved by this embodiment is the same as that of the earlier described embodiments. The remaining steps are the same as those of the first to second embodiments.
FIG. 8 is a timing chart, similar to (h) in FIG. 3, and shows a fourth embodiment of the invention. In the fourth embodiment, the reference value CPREF is set higher than the maximum value expected from integrating the pulse CP (the reference value CPREF used in the first embodiment is indicated by a two-dot chain line). Since this eventually prevents a misfire detection from being made under the aforementioned operating conditions, the effect of the fourth embodiment is the same that of the earlier embodiments.
FIG. 9 is a timing chart, similar to (f) (g) in FIG. 3, and shows a fifth embodiment of the invention. In the fifth embodiment, the reference value VCOMP is set higher than the maximum value expected. Also this eventually prevents the misfire detection similar to the fourth embodiment.
From the fourth and fifth embodiments, it will be easily understood that the same purpose can be achieved by raising both the reference values CPREF and VCOMP higher than necessary.
While it is also possible to use various other techniques, such as masking the gate interval TG, the gist of the invention is that whatever technique is used it suffices to prevent a determination that a misfire occurred from being made during periods when intentional engine output reduction control is being conducted.
Although in the above-described embodiments misfire caused by a problem in the fuel supply system is detected by reapplying a voltage after the ignition command signal has been issued, the invention is not limited to this method and also encompasses other cases such as where misfire detection is conducted on the basis of change in engine speed, as described in Japanese Laid-Open Patent Publication 61(1986)-258955.
Although examples were given in which the engine output reduction control is conducted for avoiding gear shifting shock or for mitigating swaying oscillation during acceleration, the invention is not limited to control for these purposes. Nor is it limited to the method of engine output reduction control described. Alternatively the engine output can be reduced by operating a stepper motor associated with the throttle valve for closing the throttle opening as required.
The present invention has thus been shown and described with reference to the specific embodiments. However, it should be noted that the present invention is in no way limited to the details of the described arrangements; changes and modifications may be made without departing from the scope of the appended claims.
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A high probability of detecting an erroneous misfire occurs when combustion becomes unstable during jolt control. Therefore, during jolt control the reliability of the misfire detection system is degraded. As a result, the misfire detection system is inactivated during jolt control by discontinuing the misfire detection, or by deliberately deeming no misfire has occurred if jolt control has occurred. Alternatively, the misfire detection sensitivity is masked during jolt control.
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TECHNICAL FIELD
[0001] The present invention pertains to thin film capacitors, more particularly to thin film capacitors formed on copper foil that can be embedded in printed wiring boards (PWB) to provide capacitance for decoupling and controlling voltage for integrated circuit die that are mounted on the printed wiring board package.
BACKGROUND
[0002] As semiconductor devices including integrated circuits (IC) operate at higher frequencies, higher data rates and lower voltages, noise in the power and ground (return) lines and supplying sufficient current to accommodate faster circuit switching becomes an increasingly important problem requiring low impedance in the power distribution system. In order to provide low noise, stable power to the IC, impedance in conventional circuits is reduced by the use of additional surface mount technology (SMT) capacitors interconnected in parallel. The higher operating frequencies (higher IC switching speeds) mean that voltage response times to the IC must be faster. Lower operating voltages require that allowable voltage variations (ripple) and noise become smaller. For example, as a microprocessor IC switches and begins an operation, it calls for power to support the switching circuits. If the response time of the voltage supply is too slow, the microprocessor will experience a voltage drop or power droop that will exceed the allowable ripple voltage and noise margin and the IC will trigger false gates. Additionally, as the IC powers up, a slow response time will result in power overshoot. Power droop and overshoot must be controlled within allowable limits by the use of capacitors that are close enough to the IC that they provide or absorb power within the appropriate response time. This power droop and overshoot are maintained within the allowable limits by the use of capacitors providing or absorbing power in the appropriate response time.
[0003] Capacitors for decoupling and dampening power droop or overshoot are generally placed as close to the IC as possible to improve their performance. Conventional designs have capacitors surface mounted on the printed wiring board (PWB) clustered around the IC. In this case, large numbers of capacitors requires complex electrical routing which leads to inductance. As frequencies increase and operating voltages continue to drop, power increases and higher capacitance has to be supplied at increasingly lower inductance levels. A solution would be to incorporate a high capacitance density, thin film ceramic capacitor in the PWB package onto which the IC is mounted. A single layer ceramic capacitor directly under the IC reduces the inductance to as minimum as possible and the high capacitance density provides the capacitance to satisfy the IC requirements. Such a capacitor in the PWB can provide capacitance at a significantly quicker response time and lower inductance.
[0004] Embedding ceramic capacitor films in printed wiring boards is known. Capacitors are initially formed on metal foils by depositing a capacitor dielectric material on the foil and annealing it at an elevated temperature. A top electrode is formed on the dielectric to form a fired capacitor on foil structure. The foil is then bonded to an organic laminate structure to create an inner layer panel wherein the capacitor is embedded in the panel. These inner layer panels are then stacked and connected by interconnection circuitry, the stack of panels forming a multilayer printed wiring board.
[0005] A high capacitance density capacitor can be achieved by use of a dielectric with a high permittivity or dielectric constant (K) and a thin dielectric. High dielectric constants are well known in ferroelectric ceramics. Ferroelectric dielectric materials with high dielectric constants include perovskites of the general formula ABO 3 in which the A site and B site can be occupied by one or more different metals. For example, high K is realized in crystalline barium titanate (BT), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), lead magnesium niobate (PMN) and barium strontium titanate (BST) and these materials are commonly used in surface mount component devices. Barium titanate based compositions are particularly useful as they have high dielectric constants and they are lead free.
[0006] Thin film capacitor dielectrics with a thickness of less than 1 micron are well known. Thin films can be deposited on to a substrate by sputtering, laser ablation, chemical vapor deposition, and chemical solution deposition. Initial deposition is either amorphous or crystalline depending upon deposition conditions. Amorphous compositions have low K (approximately 20) and have to be annealed at high temperatures to induce crystallization and produce the desired high K phase. The high K phase in barium titanate based dielectrics can only be achieved when grain sizes exceed 0.1 micron and so annealing temperatures as high as 900° C. may be used.
[0007] Chemical solution deposition (CSD) techniques are commonly used to form thin film capacitors on metal foils. CSD techniques are desirable due to their simplicity and low cost. High temperature annealing of barium titanate thin CSD films formed on base metal foils such as copper or nickel, require low oxygen partial pressures to avoid oxidation of the metal. The low oxygen partial pressures, however, often result in high leakage currents under applied bias (current densities) in barium titanate based compositions due to reduction of the dielectric material. In worst case situations, the capacitor may be shorted and dielectric properties cannot be measured. This may be addressed by a subsequent re-oxidation procedure carried out at lower temperatures in which the dielectric and metal foil is exposed to higher partial pressures of oxygen but this results in oxidation of the base metal foil.
[0008] A barium titanate CSD composition is disclosed in U.S. National patent application Ser. No. 10/621,796 (U.S. Patent Publication No. 2005-001185). The composition is particularly suitable for forming high capacitance density, ceramic films on copper foil. The precursor composition consists of the following chemicals:
Barium acetate 2.6 g Titanium isopropoxide 2.9 ml Acetylacetone 2.0 ml Acetic acid 10.0 ml Methanol 15 ml
[0009] However, when annealed at 900° C. in a partial pressure of oxygen of approximately 10 −11 atmospheres, the film was conducting and a re-oxidation procedure was necessary to produce parts from which electrical data could be taken. This procedure oxidized the foil and did not necessarily produce optimum capacitor performance, particularly with respect to leakage current density under bias. It is also not cost effective to re-oxidize the dielectric in a separate step. It would be an advantage, therefore, if the barium titanate composition could be doped to produce good electrical performance, particularly a low leakage current density under bias, immediately after the low oxygen partial pressure annealing process.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a dielectric thin film composition comprising: (1) one or more barium/titanium-containing selected from (a) barium titanate, (b) any composition that can form barium titanate during firing, and (c) mixtures thereof; dissolved in (2) organic medium; and wherein said thin film composition is doped with 0.002 to 0.05 atom percent of a manganese-containing additive.
[0011] The present invention is further directed to a capacitor comprising the thin film composition detailed above wherein said thin film composition has been fired in a reducing atmosphere without the need for reoxidation. Furthermore, the present invention is also directed to an innerlayer panel and a printed wiring board comprising such a capacitor.
[0012] In a further embodiment, the present invention is directed to a method of making a capacitor comprising: providing a metallic foil; forming a dielectric over the metallic foil, wherein forming the dielectric comprises: forming a dielectric layer over the foil wherein the dielectric layer is formed from the composition noted above; annealing the dielectric layer; and forming a conductive layer over the dielectric, wherein the metallic foil, the dielectric, and the conductive layer form the capacitor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The detailed description will refer to the following drawings, wherein like numerals refer to like elements, and wherein:
[0014] FIG. 1 is a block diagram illustrating a process for preparing a precursor solution used to form a dielectric that does not require a re-oxidation process.
[0015] FIG. 2 is a block diagram illustrating a process for making a capacitor on copper foil.
[0016] FIG. 3 is a graph showing capacitance density and loss tangent as a function of voltage for pure barium titanate after re-oxidation.
[0017] FIG. 4 is a graph showing leakage current density as a function of voltage for undoped pure barium titanate after re-oxidation.
[0018] FIG. 5 is a graph showing capacitance density and loss tangent as a function of voltage for 0.01 atom percent manganese doped barium titanate without re-oxidation.
[0019] FIG. 6 is a graph showing leakage current density as a function of voltage for 0.02 atom percent manganese doped barium titanate without re-oxidation.
[0020] FIG. 7 is a graph showing capacitance density and loss tangent as a function of voltage for 0.02 atom percent manganese doped barium titanate without re-oxidation
[0021] FIG. 8 is a graph showing leakage current density as a function of voltage for 0.02 atom percent manganese doped barium titanate without re-oxidation.
[0022] FIG. 9 is a graph showing capacitance density and loss tangent as a function of voltage for 0.04 atom percent manganese doped barium titanate without re-oxidation.
[0023] FIG. 10 is a graph showing leakage current density as a function of voltage for 0.04 atom percent manganese doped barium titanate without re-oxidation.
[0024] FIG. 11 is a graph showing capacitance density and loss tangent as a function of voltage for 0.01 atom percent manganese doped barium strontium titanate without re-oxidation
[0025] FIG. 12 is a graph showing leakage current density as a function of voltage for 0.01 atom percent manganese doped barium strontium titanate without re-oxidation.
DETAILED DESCRIPTION
[0026] High capacitance density thin film dielectrics and methods of making thereof are disclosed.
[0027] The manganese doped barium titanate dielectric according to the present invention may have essentially the same capacitance density and loss tangent as undoped barium titanate after re-oxidation. The manganese doped barium titanate dielectric when processed without a re-oxidation procedure, however, has a much lower leakage current density under bias than re-oxidized pure barium titanate.
[0028] BaTiO 3 is a preferred core material in the formation of high capacitance density dielectrics according to the present invention. However, metal cations with the oxide stoichiometry of MO 2 may also be used to partially or substantially substitute for titanium (e.g., Zr, Hf, Sn and mixtures thereof). While the terms “partially” and “substantially” are not meant to be particularly limiting, there are various preferred embodiments. In one embodiment, “partially” is defined as up to and including 10 molar percent of the titanium. In one embodiment, “substantially” is defined as up to and including 50 molar percent of the titanium. These broaden the temperature dependence of capacitance at the Curie point in the dielectric by “pinching” (shifting) the three phase transitions of BaTiO 3 closer to one another in temperature space. Metal cations having the oxide stoichiometry of MO (e.g., Pb, Ca, Sr and mixtures thereof) may also be used to partially or substantially substitute for barium. While the terms “partially” and “substantially” are not meant to be particularly limiting, there are various preferred embodiments. In one embodiment, “partially” is defined herein as up to and including 10 molar percent of the barium. In one embodiment, “substantially” is defined as up to and including 50 molar percent of the barium. These cations shift the dielectric Curie point to higher or lower temperatures depending upon the material used.
[0029] According to a first embodiment, a high capacitance density thin film CSD dielectric composition is disclosed that eliminates the requirement of a re-oxidation procedure after annealing the dielectric layer at a temperature in the range of approximately about 800 to 1050° C. under a low partial pressure of oxygen of less than about 10 −8 atmospheres. In one embodiment, a high capacitance density thin film CSD dielectric composition is disclosed that eliminates the requirement of a re-oxidation procedure after annealing the dielectric layer at a temperature in the range of approximately about 900° C. under a low partial pressure of oxygen of approximately 10 −11 atmospheres.
[0030] Capacitors constructed according to the above method can be embedded into innerlayer panels, which may in turn be incorporated into printed wiring boards. The capacitors have high capacitance densities, low loss tangents, and low leakage current densities under bias. Further, the methods according to the present invention may be practiced without the use of a re-oxidation treatment while using environmentally desirable materials.
[0031] Those skilled in the art will appreciate the above stated advantages and other advantages and benefits of various additional embodiments of the invention upon reading the following detailed description of the embodiments with reference to the below-listed drawings.
[0032] According to common practice, the various features of the drawings discussed below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the embodiments of the invention.
[0033] The capacitor embodiment discussed herein has a dielectric thickness in the range of about 0.4 to 1.0 μm with a capacitance density of approximately 2.5 μF/cm 2 . Capacitors of this capacitance density range have a breakdown voltage in excess of about 20 volts.
[0034] Manganese doped crystalline barium titanate is used to form high permittivity dielectric films or layers in the capacitor embodiments discussed in this specification. Manganese doped crystalline barium titanate films enables high capacitance density devices to be fabricated. The high capacitance density can be achieved using dielectric thicknesses that are physically robust, preferably between 0.4 to 1.0 μm. Manganese doping with as little as 250 ppm can be used to create the high dielectric constant dielectrics that are compatible with processing without re-oxidation procedures.
[0035] Chemical solution deposition (CSD) techniques may be used to form the dielectric. CSD techniques are desirable due to their simplicity and low cost. The chemical precursor solution from which doped BaTiO 3 is prepared preferably contains barium acetate, titanium isopropoxide, acetylacetone, acetic acid, methanol, diethanolamine, and manganese acetate tetrahydrate.
[0036] For a stable precursor solution, the above chemicals should be free of water. Water de-stabilizes the precursor composition, resulting in precipitation of titanium oxide. It is therefore important to prepare and deposit the precursor solution in relatively low humidity environments, such as less than about 40 percent relative humidity. Once the precursor solution has been fully deposited on the metal foil and dried, it is less susceptible to humidity.
[0037] FIG. 1 is a block diagram illustrating a process for preparing a precursor solution that will be used to form a dielectric according to the present invention. In step S 110 , titanium isopropoxide is premixed with acetyl acetone and heated. The premix can be done in, for example, a PYREX® container, and heating may take place on a hot plate with a surface temperature of about 90° C. In step S 120 , acetic acid is added to the Ti isopropoxide/acetylacetone mixture. In step S 130 , barium acetate and manganese acetate tetrahydrate is added into the container, and stirred until they are dissolved. In step S 140 , the solution is stirred while heated at 90° C. for a heating time of about 1 hour. In step S 150 , methanol is added to the solution to yield approximately a 0.3 molar concentration. The precursor solution is now suitable for deposition.
[0038] FIG. 2 is a block diagram of a method suitable for forming a capacitor according to the present invention. The dielectric of the resultant capacitor may be formed using the precursor solution discussed above with reference to FIG. 1 . Variants of the methanol and the acetylacetone components in the above-described precursor solution may also be used. For example, methanol may be substituted with acetic acid. Methanol may also be substituted by ethanol, isopropanol, acetone, butanol and other alcohols. Acetylacetone may be substituted by ethanolamines such as 3-ethanolamine, diethanolamine or monoethanolamine, for example. Titanium isopropoxide may also be substituted by titanium butoxide.
[0039] The deposition process illustrated in FIG. 2 is spin coating. Other coating methods, such as dip or spray coating, are also feasible. In step S 210 , a metallic foil may be cleaned. Cleaning is not always necessary but may be advisable. The metallic foil may be made from copper. Copper foils are desirable due their low cost and ease of handling. The copper foil will serve as a substrate on which a capacitor is built. The copper foil also acts as a capacitor “bottom” electrode in the finished capacitor. In one embodiment, the substrate is an 18 μm thick electroless, bare copper foil. Other untreated foils, such as 1 oz copper foil, are also suitable. Suitable cleaning conditions include etching the foil for 30 seconds in a dilute solution of copper chloride in hydrochloric acid. The etching solution may be diluted approximately 10,000 times from its concentrated form. The cleaning process removes the excess oxide layer, fingerprints and other accumulated foreign matter from the foil. If the copper foil is received from a vendor or other source in a substantially clean condition, and is handled carefully and promptly used, the recommended cleaning process may not be necessary.
[0040] The copper foil is preferably not treated with organic additives. Organic additives are sometimes applied in order to enhance adhesion of a metallic substrate to epoxy resins. Organic additives, however, may degrade the dielectric film during annealing.
[0041] In step S 220 , the precursor solution discussed above with reference to FIG. 1 is deposited over the drum side (or “smooth side”) of the copper foil substrate. The precursor solution may be applied using, for example, a plastic syringe.
[0042] In step S 230 , the substrate is rotated for spin coating. A suitable rotation time and speed are 30 seconds at 3000 revolutions per minute. In step S 240 , the substrate is heat-treated. Heat treatment may be performed, for example, at a temperature of 250° C. for five to ten minutes. Heat treatment is used to dry the precursor solution by evaporating solvents in the precursor solution. After heat treatment, the dried dielectric precursor layer is about 150 nm thick. Consecutive spinning steps may be used to coat the foil substrate to the desired thickness. Three spinning steps, for example, may be used to produce a final dried dielectric precursor thickness of approximately 0.5 μm.
[0043] In step S 250 , the coated substrate is annealed. Annealing first removes residual organic material, and then sinters, densifies and crystallizes the dried dielectric precursor. Annealing may be conducted in a high temperature, low oxygen partial pressure environment. A suitable total pressure environment is about 1 atmosphere. A suitable oxygen partial pressure is about 10 −10 to 10 −11 atmospheres.
[0044] In step S 250 , the low oxygen partial pressure may be achieved by bubbling high purity nitrogen through a controlled temperature water bath. Other gas combinations are also possible. In one embodiment, the furnace temperature is at least about 900° C., and the oxygen partial pressure is approximately 10 −11 atmospheres. The water bath may be at a temperature of about 25° C. The annealing can be performed by inserting the coated foil substrate into a furnace at temperatures below 250° C. The furnace is then ramped up to 900° C. at a rate of about 30° C./minute. The furnace is maintained at 900° C. for 30 minutes.
[0045] In step S 260 , the foil substrate is allowed to cool. Cooling may be governed by a Newtonian profile, for example, created by simply switching the furnace off. Alternatively, the furnace temperature may be ramped down at a specific rate. When the furnace temperature reaches about 450° C., the foil substrate may be safely removed from the furnace without risk of undesired oxidation effects on the copper foil. Alternatively, the furnace may be allowed to return to room temperature before the foil substrate is removed from the furnace.
[0046] In the low oxygen partial pressure annealing process, the copper foil is not oxidized to Cu 2 O or CuO. This resistance to oxidation is due to the low oxygen pressure and high processing temperature. The dielectric is also not reduced and maintains its good electrical characteristics, particularly a low leakage current density under bias. This resistance to reduction is due to the manganese acceptor doping. With manganese doping, conduction electrons are trapped by the manganese so that a decrease in insulation resistance and increase in dielectric losses are suppressed.
[0047] The high temperature annealing of 900° C. described above for densification and crystallization of the deposited dielectric provides desirable physical properties and desirable electrical properties. One desirable physical property is a dense microstructure. Another desirable physical property is resultant grain sizes between 0.1 μm and 0.2 μm. One desirable electrical property resulting from the grain size is a capacitance density in excess of 1 μF/cm 2 . An additional desirable property is a low loss tangent, which may be less than 2.5 percent. In general, dielectric constants of polycrystalline BaTiO 3 based materials fall precipitously when the average grain size falls below 0.1 μm, and grain sizes of at least this order are therefore desirable.
[0048] In step 270 , top electrodes are formed over the resulting dielectric. The top electrode can be formed by, for example, sputtering, combustion vapor deposition, electroless plating, printing or other suitable deposition methods. In one embodiment, sputtered platinum electrodes are used. Other suitable materials for the top electrode include nickel, copper, and palladium. The top electrodes may be plated with copper to increase thickness, if desired.
[0049] The following example illustrates the favorable properties in dielectrics prepared according to the present invention, and the capacitors incorporating the dielectrics.
EXAMPLE 1
[0050] A thin film un-doped pure barium titanate film was prepared on a copper foil using a precursor as disclosed in U.S. National patent application Ser. No. 10/621,796 (U.S. Patent Publication No. 2005-001185). The copper foil was coated with the dielectric precursor composition using the method outlined in FIG. 2 . The composition of the dielectric precursor was as given below:
Barium acetate 2.6 g Titanium isopropoxide 2.9 ml Acetylacetone 2.0 ml Acetic acid 10.0 ml Methanol 15 ml
[0051] Three spin coats were applied. The coated copper foil was annealed at 900° C. for 30 minutes under a partial pressure of oxygen of approximately 10 −11 atmospheres. After annealing, the pure barium titanate was re-oxidized by placing the foil in a vacuum chamber under an atmosphere of approximately 10 −5 Torr of oxygen at 550° C. for 30 minutes. This condition was chosen to avoid significant oxidation of the copper foil while still providing oxygen for re-oxidation of the dielectric. After re-oxidation, a top platinum electrode was sputtered on to the dielectric and the capacitance, dissipation factor and leakage current density under bias could be measured.
[0052] As shown in FIG. 3 , at zero bias, the capacitance density was approximately 2.5 μF/cm 2 and the loss tangent was approximately 5 percent, but the pure barium titanate layer exhibited high leakage current densities of the order of 1 amp per cm 2 under 10 volts bias as shown in FIG. 4 .
EXAMPLE 2
[0053] A thin film 0.01 atom percent manganese doped barium titanate film was prepared on a copper foil. The copper foil was coated with the dielectric precursor composition using the method outlined in FIG. 2 . The composition of the dielectric precursor was as given below:
Barium acetate 5.08 g Titanium isopropoxide 5.68 ml Acetylacetone 3.86 ml Acetic acid 21 ml Methanol 24.26 ml Manganese acetate 0.002 g Diethanolamine 0.54 g
[0054] The only difference in inorganic levels between example 1 and example 2 is the manganese. The diethanolamine is a stress reducing organic material and has no effect on the final inorganic composition. Three spin coats were applied. The coated copper foil was annealed at 900° C. for 30 minutes at a partial pressure of oxygen of approximately 10 −11 atmospheres. A top platinum electrode was sputtered on to the dielectric and the electrical characteristics of the capacitor were measured.
[0055] As shown in FIG. 5 , the doped barium titanate layer without re-oxidation exhibited a similar capacitance density and loss tangent to that of the re-oxidized pure barium titanate. However, as shown in FIG. 6 , the manganese doped barium titanate without a re-oxidation showed a low leakage current density of approximately 10 micro-amps per cm 2 at 10 volts bias or approximately 10,000 times lower leakage current flow versus the re-oxidized undoped barium titanate.
EXAMPLE 3
[0056] A 0.02 atom percent manganese doped barium titanate thin film was prepared on a copper foil in the similar manner described in EXAMPLE 1 using the precursor solution described below except the coating/pre-baking process was repeated six times. The manganese dopant solution was prepared by dissolving Mn(OAc) 2 (0.2 g) in hot acetic acid (29.8 g):
Barium acetate 2.0 g Titanium isopropoxide 2.22 g Acetylacetone 1.56 g Acetic acid 17.0 g Diethanolamine 0.21 g Manganese dopant solution 0.17 g
[0057] The capacitance density and loss tangent for a manganese doped barium titanate layer without re-oxidation are shown in FIG. 7 . The capacitance density was approximately 1.4 μF/cm 2 at 0 volt and the loss tangent was <5 percent and the dissipation factor did not degrade under bias. The lower capacitance density versus examples 1 and 2 were as a result of twice the number of coatings giving a substantially thicker dielectric. As shown in FIG. 8 , the 0.02 atom percent manganese doped barium titanate without an oxidation procedure showed a low leakage current density of approximately 10 micro-amps/cm 2 at 10 volts bias or approximately 1,000,000 times lower leakage current flow versus the re-oxidized undoped barium titanate.
EXAMPLE 4
[0058] A 0.04 atom percent manganese doped barium titanate thin film was prepared on a copper foil in the similar manner described in EXAMPLE 3 using the precursor solution described below. The coating/pre-baking process was repeated six times. The manganese dopant solution was prepared by dissolving Mn(OAc) 2 (0.2 g) in hot acetic acid (29.8 g):
Barium acetate 2.0 g Titanium isopropoxide 2.22 g Acetylacetone 1.56 g Acetic acid 17.0 g Diethanolamine 0.21 g Manganese dopant solution 0.42 g
[0059] The capacitance density and loss tangent for a manganese doped barium titanate layer without re-oxidation are shown in FIG. 9 . The capacitance density was approximately 1.3 μF/cm 2 at 0 volt and the loss tangent was ≦8 percent and the dissipation factor did not degrade under bias. As in example 3, the lower capacitance density was as a result of a thicker dielectric. As shown in FIG. 10 , the 0.04 atom percent manganese doped barium titanate without an oxidation procedure showed a low leakage current density of approximately 10 micro-amps/cm 2 at 10 volts bias or approximately 1,000,000 times lower leakage current flow versus the re-oxidized undoped barium titanate.
EXAMPLE 5
[0060] A 0.01 atom percent manganese doped barium strontium titanate (Ba 0.65 Sr 0.35 TiO 3 ) thin film was prepared on a copper foil in the similar manner described in EXAMPLE 3 except the strontium acetate was also added at the same time as the barium acetate using the precursor solution described below. The coating/pre-baking process was repeated six times. The manganese dopant solution was prepared by dissolving manganese acetate tetrahydrate (0.29 g) in a mixture of acetic acid (27.71 g) and distilled water (2.0 g):
Barium acetate 7.45 g Strontium acetate 3.17 g Titanium isopropoxide 12.67 g Acetylacetone 8.93 g Acetic acid 94.3 g Diethanolamine 1.17 g Manganese dopant solution 0.63 g
[0061] The capacitance density and loss tangent for a manganese doped barium strontium titanate layer without re-oxidation are shown in FIG. 11 . The capacitance density was approximately 1.2 μF/cm 2 at 0 volt and the loss tangent was ≦3% and the dissipation factor did not degrade under bias. As in example 3, the lower capacitance density was as a result of a thicker dielectric. As shown in FIG. 12 , the 0.01 atom percent manganese doped barium strontium titanate without an oxidation procedure showed a low leakage current density of approximately 1 mili-amps/cm 2 at 10 volts bias or approximately 1,000 times lower leakage current flow versus the re-oxidized undoped barium titanate.
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The present invention is directed to a dielectric thin film composition comprising: (1) one or more barium/titanium-containing selected from (a) barium titanate, (b) any composition that can form barium titanate during firing, and (c) mixtures thereof; dissolved in (2) organic medium; and wherein said thin film composition is doped with 0.002 to 0.05 atom percent of a manganese-containing additive.
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FIELD OF THE INVENTION
This invention generally relates to power sources. More particularly, this invention relates to inverter power sources employed in welding, cutting and heating applications.
Power sources typically convert a power input to a necessary or desirable power output tailored for a specific application. In welding applications, power sources typically receive a high voltage alternating current (VAC) signal and provide a high current output welding signal. Around the world, utility power supplies (sinusoidal line voltages) may be 200/208V, 230/240V, 380/415V, 460/480V, 500V and 575V. These supplies may be either single-phase or three-phase and either 50 or 60 Hz. Welding power sources receive such inputs and produce an approximately 10-40 volt dc high current welding output.
Welding is an art wherein large amounts of power are delivered to a welding arc which generates heat sufficient to melt metal and to create a weld. There are many types of welding power sources that provide power suitable for welding. Some prior art welding sources are resonant converter power sources that deliver a sinusoidal output. Other welding power sources provide a squarewave output. Yet another type of welding power source is an inverter-type power source.
Inverter-type power sources are particularly well suited for welding applications. An inverter power source can provide an ac square wave or a dc output. Inverter power sources also provide for a relatively high frequency stage, which provides a fast response in the welding output to changes in the control signals.
Generally speaking, an inverter-type power source receives a sinusoidal line input, rectifies the sinusoidal line input to provide a dc bus, and inverts the dc bus and may rectify the inverted signal to provide a dc welding output. It is desirable to provide a generally flat, i.e. very little ripple, dc bus. Accordingly, it is not sufficient to simply rectify the sinusoidal input; rather, it is necessary to also smooth, and in many cases alter the voltage of, the input power. This is called preprocessing of the input power.
There are several types of inverter power sources that are suitable for welding. These include boost power sources, buck power sources, and boost-buck power sources, which are well known in the art.
Generally, a welding power source is designed for a specific power input. In other words, the power source cannot provide essentially the same output over the various input voltages. Further, components which operate safely at a particular input power level are often damaged when operating at an alternative input power level. Therefore, power sources in the prior art have provided for these various inputs by employing circuits which can be manually adjusted to accommodate a variety of inputs. These circuits generally may be adjusted by changing the transformer turns ratio, changing the impedance of particular circuits in the power source or arranging tank circuits to be in series or in parallel. In these prior art devices, the operator was required to identify the voltage of the input and then manually adjust the circuit for the particular input.
Generally, adapting to the various voltage inputs in the prior art requires that the power source be opened and cables be adjusted to accommodate the particular voltage input. Thus, the operator was required to manually link the power source so that the appropriate output voltage was generated. Operating an improperly linked power source could result in personal injury, power source failure or insufficient power.
Prior art devices accommodated this problem by configuring the power source to operate at two different VAC input levels. For example, U.S. Pat. No. 4,845,607, issued to Nakao, et al. on Jul. 4, 1989, discloses a power source which is equipped with voltage doubling circuits that are automatically activated when the input is on the order of 115 VAC, and which is deactivated when the input is on the order of 230 VAC. Such sources are designed to operate at the higher voltage level, with the voltage doubling circuit providing the required voltage when the input voltage is at the lower level. This type of source, which uses a voltage doubling circuit, must use transistors or switching devices as well as other components capable of withstanding impractical high power levels to implement the voltage doubling circuit. Further, the circuitry associated with the voltage doubling circuit inherently involves heat dissipation problems. Also, the voltage doubling circuit type of power source is not fully effective for use in welding applications. Thus, there exists a long felt need for a power source for use in welding applications which can automatically be configured for various VAC input levels.
Welding power sources are generally known which receive a high VAC signal and generate a high current dc signal. A particularly effective type of the power source for welding applications which avoids certain disadvantages of the voltage doubling circuit type of power source generally relies on a high frequency power inverter. Inverter power sources convert high voltage dc power into high voltage AC power. The AC power is provided to a transformer which produces a high current output.
Power inverters for use over input voltage ranges are generally known in the art. For example, a power inverter which is capable of using two input voltage levels is disclosed in U.S. Pat. No. 3,815,009, issued to Berger on Jun. 4, 1974. The power inverter of that patent utilizes two switching circuits; the two switching circuits are connected serially when connected to the higher input voltage, but are connected in parallel to account for the lower input voltage. The switching circuits are coupled to each other by means of lead wires. This inverter is susceptible to operator errors in configuring the switching circuits for the appropriate voltage level, which can result in power source malfunction or human injury.
Other prior art welding sources that improved upon manual linking provided an automatic linkage. For example, the Miller Electric AutoLink is one such power source and is described in U.S. Pat. No. 5,319,533 incorporated herein by reference. Such power sources test the input voltage when they are first connected and automatically set the proper linkage for the input voltage sensed. Such welding power sources, if portable, are generally inverter-type power sources, and the method by which linking is accomplished is by operating the welding power source as two inverters. The inverters may be connected in parallel (for 230V, for example) or in series (e.g., for 460V). Such arrangements generally allow for two voltage connection possibilities. However, the higher voltage must be twice the lower voltage. Thus, such a power source cannot be connected to supplies ranging from 230V-460V to 380V-415V or 575V.
A 50/60 Hz transformer could be used to provide multiple paths for various input voltages. It would, however, have the disadvantage of being heavy and bulky compared to an inverter-type welding power source of the same capacity. In addition, if it was automatically linked as in the Miller AutoLink example given above, it would have to have link apparatus for each voltage. Such an automatic linkage would be complicated and probably uneconomical for the range of voltages contemplated by this invention. Thus, it is unlikely that prior art power sources that automatically select the proper of two input voltage settings will accommodate the full range of worldwide electrical input power. This shortcoming may be significant in that many welding power sources are purchased to be transportable from site to site. The ability to automatically adapt to a number of input power voltage magnitudes is thus advantageous.
It is, therefore, one object of this invention to provide a welding power source that receives any of the above-mentioned input voltages, or any other input voltage, without the need of any linkages, whether manual or automatic. Additionally, it is desirable to have such a welding power source that incorporates inverter technology and without using high power 50/60 Hz transformers.
SUMMARY OF THE INVENTION
The present invention is a power source that is capable of receiving any input voltage over a wide range of input voltages. The power source includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a desired current magnitude. Although not necessary, the output current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and an auxiliary power controller is capable of receiving a range of input voltages and provides a control power signal to the controller.
A method for providing a welding current includes rectifying an ac input and providing a first dc signal. The first dc signal is then converted into a second ac signal. Then the second ac signal is converted into a third ac signal that has a current magnitude suitable for welding. The welding current may then be rectified and smoothed to provide a dc welding current and an auxiliary power signal is supplied at a preselected control power signal voltage, regardless of the magnitude of the ac input signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the preferred embodiment of the present invention;
FIG. 2 is a detailed diagram of the input rectifier of FIG. 1;
FIG. 3 is a detailed diagram of the boost circuit of FIG. 1;
FIG. 4 is a detailed diagram of the pulse width modulator of FIG. 1; and
FIG. 5 is a control circuit for the auxiliary power controller of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the welding power source 100 includes an input rectifier 101, a boost circuit 102, a pulse-width modulator 103, a controller 104, an auxiliary power controller 105, a pair of storage capacitors C3 and C7, and their associated protective resistors R4 and R10, an output transformer T3, an output inductor L4, feedback current transformers T4 and T6, feedback capacitors and resistors C13, C14, R12 and R13, and output diodes D12 and D13 to provide a welding output current on welding output terminals 108. A cooling fan 110, a front panel 111, and a remote connector 112 are also shown schematically.
In operation, power source 100 receives a three-phase line voltage on input lines 107. The three-phase input is provided to input rectifier 101. Input rectifier 101 rectifies the three-phase input to provide a generally dc signal. A 10 microfarad capacitor C4 is provided for high frequency decoupling of the boost circuit. The dc signal has a magnitude of approximately 1.35 times the magnitude of the three-phase input. The decoupled dc bus is provided to boost circuit 102. As will be described in greater detail below, boost circuit 102 processes the dc bus provided by input rectifier 101 to provide a dc output voltage having a controllable magnitude. In the preferred embodiment the output of boost circuit 102 will be approximately 800 volts, regardless of the input voltage.
The output of boost circuit 102 is provided to pulse-width modulator 103, where the dc bus is inverted and pulse-width modulated to provide a controllable signal suitable for transforming into a welding output. Controller 104 is a main control board such as that found in many inverter-type welding power sources. The main control board provides the control signals to pulse-width modulator 103, to control the frequency and pulse-width of pulse-width modulator 103. Input rectifier 101, pulse-width modulator 103, controller 104 and output transformer T3 are well known in the art.
The output of pulse-width modulator 103 is provided to an output transformer T3, which, transforms the output of PWM 103 to provide a voltage and current suitable for welding. Transformer T3 has a center tap secondary and is provided with a turns ratio of 32 turns on the primary to 5 turns on each half for the center tap secondary. Of course, other transformers may be used. The alternating output of transformer T3 is rectified and smoothed by an output inductor L4 and output diodes D12 and D13. Inductor L4 has an inductance sufficient to provide desirable welding characteristics, such as, for example, in a range of 50-150 microhenrys.
Auxiliary power controller 105 receives the input line voltage and converts that voltage to a 18 volt dc control signal. The 18 volt control signal is created regardless of the input voltage, and is provided to boost circuit 102. Boost circuit 102 uses the 18 volt control signal to control its switching frequency and the magnitude of its output. Auxiliary power controller 105 also provides a 48 volt center tap ac power signal to controller 104.
Front panel 104 is shown schematically and is used to convey operating status to the user, as well as receive inputs as to operating parameters. Similarly, remote connector 112 is shown schematically and is used to receive inputs as to operating parameters.
Generally speaking, at power-up a three phase input is provided on input lines 107. A plurality of initially open contactors 115 isolates the input power from input rectifier 101. However, the input power is provided to auxiliary power controller 105. As will be described in greater detail below, auxiliary power controller 105 determines the magnitude of the input power, and opens or closes a number of contacts to provide a 48 volt center tap ac output to controller 104, regardless of the input. The contacts are closed and opened in such a way as to provide safeguards against underestimating the magnitude of the input voltage, and thus protecting the circuit components. Also, auxiliary power controller 105 provides an 18 volt dc control signal to boost circuit 102, regardless of the magnitude of the input.
After the voltage level has been properly determined by closing the proper contacts controller 104 causes contacts 115 to be closed, thus providing power to input rectifier 101. Input rectifier 101 includes a precharge circuit to prevent a resonant overcharge from harming capacitors C3 and C7 and to avoid excessively loading of the input source. A signal received by input rectifier 101 from a tap on transformer T3 turns on an SCR (described in more detail below). The conducting SCR bypasses input current around the precharge resistors.
The output of input rectifier 101 is provided to boost circuit 102. Boost circuit 102 is well known in the art and integrated circuit controllers for boost circuits may be purchased commercially. In operation boost circuit 102 senses the voltage at its inputs and its outputs. As will be described in more detail later and IGBT (or other switching element) is switched on and off at a frequency and duty cycle (or pulse width) to obtain a desired output voltage. In the preferred embodiment the desired output voltage is approximately 800 volts.
Boost circuit 102 thus provides an output of about 800 volts to 800 microfarad electrolytic capacitors C3 and C7, which have 45K ohm bleeder and balancing resistors R4 and R7 associated therewith. Capacitors C3 and C7 thus acts as a dc link for PWM 103.
PWM 103 receives a generally constant 800 dc signal and modulates it to provide, after transformation, rectification and smoothing, a welding output at a user selected magnitude. PWM 103 modulates its input in accordance with control signals received from controller 104. PWM 103 also receives a 25 volt dc power signal from controller 104. Such a PWM is well known and PWM 103 may be purchased commercially as a single module.
The output of PWM 103 is provided to output transformer T3 and which transforms the relatively high voltage, low current signal to a voltage suitable for use in welding. The output of transformer T3 is rectified by diodes D12 and D13, and smoothed by output inductor L4. Thus, a generally constant magnitude dc welding output is provided on welding outputs 108.
Current transformers T4 and T5, provide feedback signals to controller 104, snubber capacitors C13 (0.1 microfarads) and C14 (0.022 microfarads), and snubber resistors R12 (12 ohms) and R13 (47 ohms) suppress voltage transients associated with recovery of D12 and D13. Controller 104 compares the feedback signals to the desired welding current, and appropriately controls PWM 103 to adjust its switching pulse width if necessary.
Referring now to FIG. 2, the preferred embodiment for input rectifier 101 is shown in detail and includes a full wave bridge comprised of diodes D4, D5, D6, D9, D10 and D11. The bridge rectifies the three phase input to provide a signal having a magnitude of about 1.35 times the input voltage magnitude. A pair of 50 ohm resistors R1 and R2 are provided to precharge capacitors C4, C3 and C7 (shown in FIG. 1) upon start up. This prevents a sudden surge of current from being dumped into capacitors C4, C3 and C7.
After the precharge is completed an SCR Q1 is turned on via a signal from a tap on output transformer T3 (also in FIG. 1). The signal from transformer T3 is provided to the gate of SCR Q1 via a current limiting resistor R6 and capacitor C6. A recovery diode D7 and snubber resistor R5 are provided across the gate of SCR Q1. SCR Q1 shunts the resistors and allows the maximum current flow to inductor L2 of boost circuit 102.
A plurality of varistors RV1-RV3 are provided to suppress line spikes. Additional varistors (not shown) may be provided between D9-D11 and ground to further suppress spikes.
As one skilled in the art will readily recognize, other circuits and circuit elements will accomplish the function of input rectifier 101.
Referring now to FIG. 3, the details of one embodiment of boost circuit 102, which operates in a manner well known in the art, is shown. Generally speaking, boost circuit 102 provides an output voltage that is equal to the input voltage divided by one minus the duty cycle of a switch IGBT1 in boost circuit 102.
Thus, if the switch IGBT1 is off 100% of the time the output voltage (the dc link voltage) is equal to the input voltage (from capacitor C4 and input rectifier 101). In one embodiment the lowest input is about 200 volts, and the desired output (dc link voltage) is 800 volts, thus the upper limit for the "boost" is about 400%, and requires a duty cycle of about 75%.
The operation of a boost circuit should be well known in the art and will be briefly described herein. When switch IGBT1 is turned on, current flows through an inductor L2 to the negative voltage bus, thus storing energy in inductor L2. When switch IGBT1 is subsequently turned off, the power is returned from inductor L2 through a diode D1 and a 14 microhenry saturable reactor L1 to the dc link. The amount of energy stored versus returned is controlled by controlling the duty cycle in accordance with the formula stated above. In order for the boost circuit to operate properly inductor L2 must have continuous current, therefore inductor L2 should be chosen to have a large enough inductance to have a continuance current over the range of duty cycles. In one embodiment inductor L2 is a 3 millihenry inductor. The remaining elements of boost circuit 102 include a 0.0033 microfarad capacitor C1, a diode D3, a 1 ohm resistor R3, a 50 ohm resistor R6, a diode D8, a 50 ohm resistor R7 and a 0.1 microfarad capacitor C8 which are primarily snubbers and help the diode recover when switch IGBT1 is turned on.
Boost circuit 102 includes an IGBT driver 301 that controls the duty cycle of switch IGBT1. Driver 301 receives feedback signals indicative of the output voltage and the input current, and utilizes this information to drive switch IGBT1 at a duty cycle sufficient to produce the desired output voltage.
In one embodiment, boost circuit 102 includes a shunt S1 (shown on FIG. 1). Shunt S1 provides a feedback signal that is the current flowing in the positive and negative buses. A Unitrode power factor correction chip is used to implement boost circuit 102 in the preferred embodiment and requires average current flow as an input. In response to this information and the dc link voltage, driver 301 turns switch IGBT1 on and off.
As one skilled in the art will readily recognize, other circuits and circuit elements will accomplish the function of boost circuit 102.
As stated above, the output of boost circuit 102 is provided to capacitors C3 and C7 (FIG. 1) and is the dc link voltage. In one embodiment the dc link voltage is 800 volts, as determined by the switching of switch IGBT1. In the preferred embodiment, using the component values described herein the dynamic regulation of the dc link voltage is 80 volts from full load to no load. Static regulation is about a ±2 volts, with a ripple of about ±20 volts.
The dc link voltage is provided to pulse width modulator 103. PWM 103 is a standard pulse with modulator and provides a quasi-square wave output having a magnitude equal to the magnitude of the input, as would any other PWMs. Thus, the output of PWM 103 is about +400 volts to -400 volts for an 800 volt peak to peak centered about zero.
PWM 103 includes a pair of switches Q3 and Q4 (preferably IGBTs) and a pulse width driver 401. Driver 401 receives feedback from current transformers T1 and T2, and receives control inputs from controller 104. In response to these inputs driver 401 provides gate signals to switches Q3 and Q4, thereby modulating the input signal. A capacitor C2 (4 microfarad) a capacitor C9 (4 microfarad) are provided between the dc link and the output transformer T3. A capacitor C5 (0.0022 microfarad), resistor R11 (50K ohm) and resistor R9 (50K ohm) are snubber circuits.
As one skilled in the art will readily recognize, other circuits and circuit elements will accomplish the function of PWM 103.
The output of PWM 103 is provided to transformer 103, and the current in transformer 103 is determined by the modulation of PWM 103. As stated above, the output of transformer T3 is rectified by diodes D12 and D13 and is smoothed by inductor L4. The dc output current is fairly flat; the ripple at full load (300 amps) is about 12 amps peak to peak. At full load the duty cycle of each switch Q3 and Q4 of PWM 103 would be about 20-35% (40-70% overall duty cycle).
In an alternative embodiment the output of PWM 103 may be rectified by other output rectifiers such as a synchronous rectifier (cycloconverter) that provides an ac output signal at a frequency less than or equal to the frequency of the output of PWM 103. Other output circuits, including inverters, that provide a welding current may also be used.
Referring again to FIG. 1, controller 104 is connected to current transformers T4 and T5, which provide feedback information. Controller 104 receives power from auxiliary power controller 105 and provides as one of its output the driver control for the PWM driver. It also includes an over voltage protection sense which monitors the voltage coming out of input rectifier 101. If the voltage from input rectifier 101 is dangerously high controller 104 causes contactors 115 to open, to protect circuit components. According to one embodiment 930 volts dc is the cut off point for what is considered to a dangerously high voltage.
As may be seen from the above description, welding power source 100 receives an input voltage and provides a welding output. Regardless of the magnitude of the input voltage boost circuit 102 boosts the input voltage to a desired (800 volts e.g.) level. Then PWM 103 modulates the signal to provide an appropriate level of power, at 800 volts, to transformer T3.
The above arrangement is satisfactory for any input voltage, however, there must be some mechanism to provide control voltages at the proper level. As will be described below, auxiliary power controller 105 performs that function, and the embodiment thereof is shown schematically in FIG. 5.
With reference now to FIG. 5, a plurality of connectors J1, J2, J3 and J4 are shown. An 18 volt dc control voltage output is provided on connector J1 to boost circuit 102 (shown on FIG. 1). As will be described in greater detail below, the 18 volt dc control signal is provided regardless of the magnitude of the input Voltage. Connector J2 feeds power back to auxiliary power controller 105 for internal use. Connector J3 connects the input ac voltage to appropriate taps on a transformer T7 (FIG. 1) to provide a 30 volt ac signal to remote connector 112 (FIG. 1). Similarly, a 48 volt center tap ac signal is provided to controller 104. Controller 104 uses the 48 volt center tap ac signal to generate dc control signals and to power fan 110. Connector J4 of auxiliary power controller 105 is connected via a user controlled on/off switch S4 to the input power lines (FIG. 1).
Auxiliary power controller 105 controls the connections to taps on the primary of an auxiliary power transformer T7. Transformer T7 is a 200 VA transformer whose primaries are connected to auxiliary power controller 105 as described above with reference to connector J2 add J3. Several taps on its secondary are connected to controller 104 and the remaining secondary taps are connected to remote connector 112.
Referring again to FIG. 5, the taps on J3 are associated with the following voltages: 575, 460, 380, 230 volts, and the return, beginning at the uppermost tap and proceeding downward. As will be described below, when auxiliary power controller 105 selects the appropriate tap for a given input voltage, transformer T7 will provide a 48 volt center tap ac signal on its secondary for use by controller 104.
As may be seen on FIG. 5, the ac input is received on connector J4 and provided (via a fuse F1, and a pair of 4.7 ohm resistors R18 and R19) to a series of relays K2B, K1B, K3C and K3B that determine the tap on connector J3 selected for the output. When 575 volts are present at the input relays K2B and K3C should be to the right. Then the input is connected across the upper and lower most taps on connector J3. These taps are connected to the appropriate taps on transformer T7 such that the output of transformer T7 that is provided to controller 104 is approximately 48 volts center tap when 575 volts are provided to the primary of transformer T7.
When 460 volts are present at the input relay K2B should be to the left, and relay K1B should be to the right. This connects the ac input to the second uppermost and the lowest taps on connector J3. The remaining voltages are similarly accommodated. A pair 0.15 microfarad capacitors C13 and C14 are provided for snubbing and spike suppression as the primaries of transformer T7 are switched.
In operation the circuitry on the left side of FIG. 5 determines the input voltage, and sets the relays for that voltage. At start up the relays are as shown in FIG. 5 and are suitable for an input voltage of 575 volts. Because this is the highest possible input voltage, all components will be protected, i.e. either the voltage is properly selected, or the input voltage is less than the component design capabilities. If auxiliary power controller 105 determines that 575 volts are in fact present, the relays will remain as shown. However, if auxiliary power controller 105 determines that less than 575 volts are present, the state of relay K2B will be changed (to be to the left), so that the output is appropriate for a 460 volt input.
This process is repeated, always stepping down to the next highest voltage, until the appropriate input voltage is sensed. In this manner the components in controller 104 will be protected from a dangerously high voltage being applied to controller 104.
The voltage for sensing is provided to auxiliary power controller 105 via connector J2, which is connected to secondary taps on transformer T7. Thus, if the tap selected on connector J3 was not correct, then the voltage on connector J2 will be too low, and auxiliary power controller 105 will select the appropriate relay setting to step down to the next voltage level. As stated above, the stepping down continues until the proper voltage is sensed on connector J2.
The input from connector J2 is provided to a rectifier comprised of diodes CR1, CR2, CR3 and CR4. These diodes rectify the ac signal and provide it to a pair of 220 microfarad smoothing capacitors C1 and C2. The rectified voltage is ±18 volts dc if the proper tap on connector J3 is selected. If the incorrect tap is selected the voltage will be less than ±18 volts, but will be referred to as nominally ±18 volts. The nominal ±18 volt supply is provided at other locations throughout the auxiliary power controller 105 circuit, including to a 30 volt zener diode CR7, used to determine if the proper tap on connector J3 has been selected.
Auxiliary power controller 105 determines if 575 volts is present on the input using the following components: zener diode CR7, a 10 microfarad capacitor C9, a pair of gates U2B and U2C configured as darlington drivers for a winding K2A of relay K2, a 10K ohm resistor RN2A, a 10K ohm resistor RN2B, a 820 ohm resistor R9, and a diode U3B. Gates U2B and U2C are also used as sensing devices and have a threshold of about 4 volts (relative to their reference voltages) on the input (pin 1) of gate U2B pin 1.
Initially, gate U2B has a LOW output and is referenced to nominal -18 volts. Gate U2B will not switch states so long as the input is at least 4 volts greater than its reference voltage (nominally -18 volts relative to ground). In operation the nominal +18 volts will be provided to diode CR7 and the nominal -18 volt signal is applied to a 10 microfarad capacitor C9. As a result of the 30 volt zener drop, the input to gate U2B will be at -12 volts (relative to ground) if the proper tap has been selected. If 575 volts are present at the input, there will be 6 volts relative to the reference voltage (-18 volts) at the input to op amp U2B, and the output state of gate U2B will remain low. So long as the output of U2B remains low the current will not flow in the winding of relay K2 and relay K2B will remain as shown in FIG. 5.
However, if only 460 volts are present on the input and the relays are as shown in FIG. 5 (as they will be at power up), then the nominal ±18 volts will actually be ±14.4 volts. Thus, 28.8 volts are applied across zener diode CR7 and capacitor C9. Given the 30 volt zener drop, -14.4 volts will be applied to the input of gate U2B. Because this is also the reference voltage for gate U2B, the threshold is crossed, and the output of gate U2B will change states. Current will then flow in the winding of relay K2 and relay K2B will change states, configuring the J3 taps for 460 volts. If less than 460 volts is present at the input the same result will occur.
The sensing and stepping down to 380 volts and 230 volts occur in a similar manner using similar components. Referring to FIG. 5, the sense and step down circuit to 380 volts include a 100 ohm resistor R17, a pair of 10K ohm resistors RN2C and RN2D, an 820 ohm resistor R8, a diode U3C, a 10 microfarad capacitor C6, a pair of gates U2D and U2E, and a winding K1A for relay K1. A relay K2C is provided to prevent relay K1 from changing states before the step down to 460 volts occurs. In the manner described above with respect to the step down to 460 volts, the current will be provided to winding K1A of relay K1 if less than 460 volts is provided at the input. This will cause relay K1B to move to the left position and connect the tap on J3 associated with a 380 volt input.
The circuitry associated with the step down to 230 volts includes a 100 ohm resistor R16, a pair of 10K ohm resistors RN1A and RN1B, an 820 ohm resistor R11, a diode U3E, a pair of gates U2F and U2G, a winding K3A for relay K3, relay K1C, diode CR5 and zener diode CR4. A relay K1C is provided to prevent relay K3 from changing states before the step down to 380 volts occurs. The step down to 230 volts operates in the same manner as the step down to 380 volts and 460 volts as described above. If less than 380 volts is applied on the connector J4 inputs, gates U2F and U2G will cause current to flow through winding K3A of relay K3. This will cause relay K3B to move to the left and connect the tap on J3 for 230 volts to the ac input.
Thus, as may be seen from the above description, the circuitry of auxiliary power controller 105 senses the ac input voltage and connects the appropriate tap on the auxiliary power transformer T7 to the ac input voltage. As may be seen from the above discussion, this is done in a manner which protects components by assuming the voltage is, upon start up, the highest possible voltage. If the voltage is less than the highest possible voltage, the next lowest voltage will then be assumed. This process is repeated until the actual voltage is obtained.
In the event that the ac input is 230 volts, at start up there will not be sufficient power from the nominal ±18 volt signal to drive the relays because the tap associated with 575 volts on connector J3 is selected at start up. To compensate for this, circuitry that boosts the voltage supplied on connector J2 is provided. This circuitry includes a 1 millihenry inductor L1, a switch Q4, a timer U1, a switch Q2, a switch Q1, and a switch TIP120. Also included are associated circuitry including a 22 ohm shunt resistor R13, a 1K resistor R5, a 10K resistor R12, a 10K resistor R14, a 2.2K resistor R4, a 1K resistor R6, a 1K resistor R2, a 20K resistor R3, a 220 ohm resistor R7, a 10K resistor RN1D, a 4.7K resistor R10, a 470 picofarad capacitor C4, a 0.001 microfarad capacitor C3, a 0.1 microfarad capacitor C5, a 220 microfarad capacitor C11, a 220 microfarad capacitor C12, a diode CR12, a diode CR8, a zener diode CR10, a diode CR5, and a zener diode CR11.
The boost power source circuitry operates as a typical boost circuit. The boost is provided by inductor L1 and switch Q4. During the time switch Q4 is ON, current flows through inductor L1, shunt resistor R13 and switch Q4 to the negative voltage supply. During this time, energy is stored in inductor L1. When switch Q4 is OFF, the energy stored in inductor L1 is returned to the positive voltage supply (+B) through diode CR12. By appropriate timing of the turning ON and OFF of switch Q4, a desired voltage may be obtained. Timer chip U1 is used to provide the ON/OFF gate signals to switch Q4 and is an LM555 timer. When the voltage on resistor R13 becomes sufficiently high, it will trip the input on U1, which in turn will cause the output of timer U1 to turn switch Q4 OFF.
Initially, switch Q4 is in the ON position and current increases and eventually reaches the point where the voltage on resistor R13 is sufficiently high to trip the threshold on timer U1 through resistor R12. Thus, switch Q4 will remain ON for a length of time sufficient to build up enough energy to, when it is turned OFF, raise the nominal ±18 volts to a level sufficient to drive the relays.
Switches Q2 and Q1 enable or disable timer U1 when the taps on connector J3 are such that the nominal ±18 volt signal is actually ±18 volts. When switch Q2 is turned OFF, timer U1 is disabled through its VCC input. Also, switch TIP120 is a linear regulator. When the nominal +18 volt supply is insufficient to drive the relay, switch TIP120 will provide the boost source to drive the relays. When the nominal +18 voltage is sufficient to drive the relay, switch Q2, timer U1 and switch Q4 are turned off. The +18 volt supply is coupled through L1 and CR12 to regulator TIP120; the +B boost supply is then fed directly by the sufficiently high +18 volt supply. The TIP120 regulator regulates relay supply at 24 volts relative to the -18 volt supply.
In addition to the circuitry above, circuitry is provided that protects in the event of an overvoltage. This circuitry includes a switch Q5, a gate U2A, a 100 ohm resistor R15, a 10K ohm resistor RN3A, a 10K ohm resistor RN3B, a 10K ohm resistor RN3C, a 10 microfarad capacitor C10, diodes CR14 and U3H, and 10 volt zener diode CR13. An overvoltage occurs when the tap selected on connector J3 corresponds to a voltage less than the voltage at the ac input. This may occur when either the incorrect tap has been selected or when a temporarily high voltage is provided at the ac input.
In the event an overvoltage occurs, the voltage at the node common to diodes CR13 and CR7 will rise to a voltage greater than 14 volts with respect to the nominal -18 volt signal. This causes the low side of diode CR13 to be greater than 4 volts with respect to the nominal -18 volt signal, and the input of U2A will change from an input low state to an input high state. When the input of U2A changes from low to high, the output will change from an output high state to an output low state. The output low state of U2A will bring the relay supply voltage to a virtual 0 through diodes U3H and CR14. This causes the relays to return to the state shown in FIG. 2, which accommodates the highest voltage possible (575 volts). At that time the previously described tap selection process stepping from the 575 to 460 to 380 to 230 taps begins again until the correct tap is selected to match the input voltage received on connector J4. Accordingly, the components of controller 104 will be protected.
Other modifications may be made in the design and arrangement of the elements discussed herein without departing from the spirit and scope of the invention as expressed in the appended claims.
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A method and apparatus for providing a welding current is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding. The welding current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and an auxiliary power controller that can receive a range of input voltages and provide a control power signal to the controller.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet printer that uses heat energy for ejecting ink droplets toward a recording medium.
2. Description of the Related Art
Japanese Patent Application Kokai Nos. SHO-48-9622, SHO-54-51837, SHO-54-59936, SHO-54-161935 describes a type of ink jet printer with channels filled with ink and nozzles, each in fluid communication with an ink channel. A pulse of heat is applied to the ink, which rapidly vaporizes as a result. The expansion of the resultant vapor bubble ejects a droplet of ink from the corresponding nozzle.
The most effective method of producing the heat pulse is with a thin film thermal resistor provided in the ink channel. Practical examples of thin film thermal resistors are described at page 58 of the "Nikkei Mechanical", published Dec. 28, 1992 and th "Hewlett-Packard Journal" published August 1988. These thermal resistors commonly include a thin film resistor with a great thermal endurance, a metal thin film conductor, and a two-layer protective covering over the thin film resistor and the metal thin film conductor. The thin film forming the thin film resistors is about 0.1μ thick. The two-layer structure of the protective covering is about 3 to 4μ thick in total. The first layer of the protective covering is in contact with the thin film resistor and the metal thin film conductor and is for protection against oxidation and electrochemical corrosion. The second protective layer is provided for protecting the first protective layer against damage from cavitation.
Thermal resistors constructed as described above are used to pulse heat and rapidly vaporize the portion of the ink adjacent to the thermal resistor. Ink droplets are ejected by expansion of the resultant bubbles. Printers must be able to rapidly repeat the ejection process which includes not only expansion of bubbles, but also the contraction and final disappearance of bubbles. Four conditions are required to produce a printer that can eject ink droplets stably and rapidly in succession at a high frequency.
The first condition relates to the generation of bubbles. Japanese Patent Application Kokai Nos. SHO-55-27282 and SHO-56-27354 teach that in order to increase ejection efficiency, response, and frequency characteristics, the temperature at the surface of the thermal resistor must be rapidly increased to thereby invoke film boiling in the ink in contact with the thermal resistor, and the processes A through E shown in FIG. 1, which show the boiling characteristic curve of water, should be kept as short as possible. However, there are two points in the technical explanation and understanding in these publications which need correction.
The first point to be corrected in that the boiling characteristic curve shown in FIG. 1 represents a set stable state whereas ejection of ink droplets occurs in an unstable state. In the boiling characteristic curve shown in FIG. 1, the temperature at the heater surface that contacts the water is stable or rises and lowers slowly. Boiling which occurs from application of a pulse of heat is unsteady boiling. In fact, in subsequent research (see page 7 of Collection of Presentations from the 22nd Japan Thermal Transmission Symposium 1985-5), the inventors of the above-listed applications disclose that tests bubbles were generated at 263° C. This temperature matches the superheating limit of 270° C. predicted by the theory of spontaneous nucleation. That is, bubbles are generated by unstable boiling, which is a very different phenomenon from the phenomenon of stable boiling represented in FIG. 1.
The second point to be corrected is the inappropriate use of the term film boiling. Film boiling assumes that conditions continue for a certain length of time. However, an extremely short pulse of heat rapidly generates a single bubble that vanishes in an extremely short period of time. In later research (see page 7 of the Collection of Presentations from the 22nd Japan Thermal Transmission Symposium 1985-5, on page 247 of the Collection of Presentations from the Journal for the 23rd Japan Thermal Transmission Symposium 1986-5, and on page 253 of the Collection of Presentations from the Journal for the 25th Japan Thermal Transmission Symposium 1988-6), the inventors of the above-listed applications changed their opinions to say that a small bubble is formed from spontaneous nucleation (also referred to as nonhomogeneous nucleation) at a portion of the heater surface and afterward rapidly expands to the entire surface of the heater.
Therefore, it is technically incorrect to say that in order to increase ejection efficiency, response, and frequency characteristics, the temperature at the surface of the thermal resistor must be rapidly increased to thereby invoke film boiling in the ink in contact with the thermal resistor, and the processes A through E shown in FIG. 1, which shows the boiling characteristic curve of water, should be kept as short as possible. Taking the two points into consideration, a more accurate statement would be that the ink in contact with the surface of the heater should be brought into a film boiling condition in as short a time as possible.
Japanese Patent Application Kokai No. HEI-03-266646 describes a thermal ink jet print heat which uses a boiling phenomenon appearing when ink is heated under conditions different from those in the above-described research. The surface of the heater is raised at a speed of 10 6 to 10 9 ° C./S and the heat flux from the heater surface to the ink is set at 10 7 to 10 8 W/m 2 . The temperature at the heater surface and the ink adjacent to the heater surface is rapidly heated to the temperature at which homogeneous nucleation occurs. Ink is ejected by a homogeneous nucleated bubble.
The type of boiling that is ordinarily observed occurs by vapor nucleation. For example, vapor nucleation occurs at defects in the solid surface in contact with water when the temperature of the water reaches about 100° C.
Spontaneous nucleation occurs when no defects are present in the solid surface in contact with the liquid to be boiled, that is, when the solid surface is perfectly uniform. Boiling activated by spontaneous nucleation occurs simultaneously over the entire boundary between the solid surface and the liquid. When the liquid to be boiled is water, boiling will start only when the temperature at the solid surface reaches about 270° C. Spontaneous nucleation is also referred to as non-homogeneous nucleation because thus activated boiling occurs where solid and liquid coexist.
Homogeneous nucleation occurs only in superheated homogeneous liquids in contact with a uniform solid surface, as described above for spontaneous nucleation, that is rapidly heated. Refer to V. P. Skripove, Metastable Liquids, John Wiley, New York 1974. The temperature at which homogeneous nucleation is assumed to occur in water is 312.5° C. However, it is technically difficult to produce a heater which an generate the extremely rapid increase in temperature necessary for homogeneous nucleation to occur. In fact, there has been no confirmation of an actual heater with this capability.
Homogeneous nucleation is termed homogeneous, despite the presence of a solid surface, because homogeneous nucleation can be observed only in homogeneous liquids. Boiling begins in water adjacent to the boundary between the liquid and the solid surface when critical values for both the speed at which the solid surface rises and the heat flux that is transmitted to the liquid from the solid surface are exceeded and when the temperature at the solid surface and the water adjacent to the solid surface exceeds 312.5° C.
Recently, Iida et al experimentally verified this phenomenon as discussed on page 334 of Collection of Presentations from the 27th Japan Thermal Transmission Symposium 1990-5. The invention described in Japanese Patent Application Kokai No. HEI-03-266646 is based on the results of these experiments, in which the thermal resistor and the electrode are formed from the same material. However, the width of the electrode is at least five times and up to ten times the width of the thermal resister. This makes manufacturing an inexpensive large-scale line head difficult, although a head with a low density of 30 dpi could possibly be produced. That is, using this thermal resistor in a high density multi-nozzle type ink jet print head would be impossible without adding some further contrivance.
The second condition relates to the speed at which the thermal resistor is heated. Japanese Patent Application Kokai No. SHO-55-161664 teaches that the average speed at which temperature of the thermal resistor increases (hereinafter referred to as "average speed of temperature increase") should be 1×10 6 ° C./sec or more, preferably 3×10 6 ° C./sec or more, and optimally 1×10 7 ° C./sec or more. The liquid described in the publication is ink made mainly from ethanol. Recently, Iida et al performed precise experiments using pure ethanol. The average speed of temperature increase and the number of bubbles generated during these experiments are described in detail on page 712 of Collection of Presentations from the 28th Japan Thermal Transmission Symposium 1991-5. Although some discrepancies in the data can be accounted for by differences between pure ethanol and ink made mostly from ethanol, the most noteworthy result is that bubbles were generated at a density, which most closely governs ejection of ink, that was two orders of magnitude greater in ethanol than in water at the same average speed of temperature increases. That is, in order to generate the same number of bubbles in the same density, water must be heated at an average speed of temperature increase that is ten times faster than the average speed of temperature increase required for ethanol.
Therefore, a great technological leap is required to apply the invention described in Japanese Patent Application Kokai No. SHO-55-161664 to water based ink. An extremely fast average speed of temperature increase of about 1×10 8 ° C./sec or more is required to stably eject water based ink. Asai et al performed experiments using water based ink as described on page 253 of the Collection of Presentations from the 25th Japan Thermal Transmission Symposium Collection of Presentations 1988-6. The speed of ink ejection was unstable at the extremely fast average speed of temperature increase of about 0.9×10 8 ° C./sec. (270° C./3 μsec). On the other hand, the value described in Japanese Patent Application Kokai No. HEI-03-266646, that is, 10 6 to 10 9 ° C./sec or greater, does not clearly show the value or range of the thermal speed.
The third condition relates to the time between when the heat pulse starts and when the liquid starts to boil (hereinafter referred to as "the time to boiling start"). Asai et al discloses use of a naked heater without protective layers (page 7 of the Collection of Presentations from the 22nd Japan Thermal Transmission Symposium 1985-5). Although the lack of protective layers improves rate of heat transmission, it also reduces reliability Asai et al described tests using ethanol. Bubbles can be generated in ethanol at a temperature 70° C. less than the temperature for generating bubbles in water. Asai et al used strobe techniques to observe the time between when a bubble was generated to when the bubble disappeared. Results of these observations are schematically shown in FIG. 2. Times listed indicate time elapsed after the initiation of a 10 μS heat pulse. As can be seen, generation of the bubble begins 4 μS after start of the thermal pulse. The bubble is at its maximum size at about 8 μS after start of the thermal pulse. Afterward the bubble begins to contract. Secondary bubbles are generated after the first main bubble until the last secondary bubble completely vanishes at about 20 μS after start of the heat pulse.
Asai et al describes using a heater similar to the above-described naked heater, but with a two-layer protective structure covering the alloy thin film resistor, in order to generate bubbles in water, which has nearly the same qualities as water based ink (page 247 of Collection of Presentations from the 23rd Japan Thermal Transmission Symposium 1986-5). The results of the test are shown in FIG. 3. Power was applied so that the generation of a bubble begins at the declining edge of the thermal pulse (that is, when application of power is stopped). With this type of heater covered with the two-layer protective layer, 7 μS was required from when generation of the bubble began to when the bubble reached its maximum size. This time is fixed and independent of the duration of the thermal pulse. No data was provided for time required for the bubble to disappear. However, because generation of secondary bubbles, which is a phenomenon similar to the bubble rebound phenomenon observed during cavitation, can also be observed when the pulse width of the thermal pulse is 10 μS long, it can be assumed that bubbles begin to disappear about 25 to 30 μS after start of bubble generation.
Asai et al discloses results of generating a bubble in actual water based ink using a heater covered with the two-layered protective structure (page 253 of the Collection of Presentations from the 25th Japan Thermal Transmission Symposium 1988-6). Microscopic bubbles appeared at a portion of the heater surface at approximately 3 μS after the start of the heat pulse. Afterward, a bubble was generated over the entire surface of the heater. Asai et al did not measure the temperature at the surface of the heater nor the heat flux to the liquid in tests of the third condition.
In contrast to this, Iida et al performed tests to accurately measure these values (see page 334 of Collection of Presentations from the 27th Japan Thermal Transmission Symposium 1990-5). Iida et al heated water using a heat pulse with duration of 5 μS or more. Initial boiling nucleation in water was observed using a strobe light with an extremely short pulse of 10 nanoseconds. The shortest boiling start time was about 3.7 μS. Theoretically predicted parameters of the average speed of temperature increase and the average speed of heat flux match with the conditions observed before and after the start of boiling. Two experiments and the results of the experiments are discussed below.
(1) In one experiment, heat was applied to 20° C. water at an average speed of temperature increase of 0.56×10 8 ° C./sec or greater and with an average heat flux of 1.5×10 8 W/m 2 or greater. The temperature at the surface of the heater at the start of boiling matched the theoretical temperature (312.5° C.) at with homogeneous nucleation is believed to occur in water at atmospheric pressure. It was determined that boiling caused by this type of rapid heating is independent of the degree of liquid subcool (that is, the difference between the bulk temperature and the temperature at the surface of the heater when boiling starts).
(2) In another experiment, heat was applied at an average speed of temperature increase of 0.70×10 8 ° C./sec or greater and with an average heat flux of 2.1×10 8 W/m 2 or greater, whereupon boiling caused by swing nucleation was observed for the first time in water. It should be noted that boiling did not occur by swing nucleation when the average speed of temperature increase or the average heat flux was less than these values. The characteristics of swing nucleation as observed in the above experiment are that first a multiplicity of small bubbles with a uniform size are generated across the entire surface of the heater at a uniform distribution. The number of bubbles rapidly increases. The bubbles couple to form a bubble film at the surface of the heater.
Contrarily, in normal homogeneous nucleation, small bubbles are generated erratically on the surface of the heater. The bubbles enlarge and couple to form the bubble film. The time period from nucleation to formation of the bubble film is much slower in normal homogeneous nucleation than in swing nucleation, which requires only 1 μS or less. Although the time period from nucleation to formation of the bubble film has not been measured in spontaneous nucleation (nonhomogeneous nucleation), considering that the speed of temperature rise and the heat flux are comparatively small values, the speed of formation is probably fairly slow.
In summary, the speed from the start of boiling to formation of a bubble film is slowest in spontaneous nucleation, faster in homogeneous nucleation, and fastest in swing nucleation. The shortest observed example of time from heat pulse to boiling is about 3 μS. This can be estimated as the limit for conventional thermal resistors which require a thick two-layer protective covering.
The fourth condition for allowing stable ejection of ink at a high repetition speed relates to the contraction and disappearance of bubbles. There have been many attempts to control the speed at which bubbles contract and disappear in order to smooth recuperation of the meniscus after ejection and moreover to shorten the frequency and increase the speed of ejections. For example, Japanese Patent Application Kokai No. SHO-55-132267 describes setting the duration of time required for the surface of the heater to cool to longer than the time required to heat the surface of the heater. Japanese Patent Application Kokai Nos. SHO-55-161662, SHO-55-161663, and SHO-56-13177 describe setting the time required for the temperature at the surface of the heater to cool by half to a duration of time longer than the time required to heat the surface but shorter than four times the time required to heat the surface. However these publications do not accurately disclose data or the technical basis for these determinations. Additionally, the technical content and results of controlling the speed of bubble contraction and disappearance is questionable.
Publications by Asai and others refute these inventions (Collection of Presentations from the 22nd Japan Thermal Transmission Symposium 1985-5 and in Collection of Presentations from the 23rd Japan Thermal Transmission Symposium 1986-5). A film shaped bubble generated on the heater by application of a pulse of heat expands explosively at high pressure (several tens to hundreds of atmospheres) and at high temperature (about 300° C.). Expanding gas in the bubble is cooled by the surrounding room temperature liquid, i.e., the ink. When the bubble is at its maximum size, the interior of the bubble is almost a complete vacuum. In the next instant, the bubble begins to contract, and vanishes in about 5 μS. The heat flux from the surface of the heater to the bubble is negligible when the heater is covered by the bubble. Therefore, the speed of contraction is virtually constant and independent of the temperature at the surface of the heater.
However, when the temperature at the surface of the heater does not decrease even after the initial bubble disappears, secondary bubbles are repeatedly generated. Generation of secondary bubbles interferes with recuperation of the meniscus after ink is ejected. Inducing boiling by heating at portion of a liquid that is cooler than boiling temperature is termed subcool boiling. Thermal ink jet print heads use subcool boiling when the amount of subcooling is large. As can be seen in FIG. 3, the time required for a bubble to contract and disappear is twice as long as the time required to generate the bubble. Before a bubble is generated, a pulse of heat with long duration (10 to 50 μS) is applied to heat the water on the heater, to increase the volume of water that boils as a result, and to increase the volume of the bubble. The time for contraction of the resultant large volume bubble is about 10 μS. Whether the secondary generation of bubbles shown in FIG. 3 results from insufficient cooling of the heater temperature or from cavitation by the contraction of the bubble volume is unknown, but secondary generation of bubbles occurs in all bubble contractions in conventional technology.
In Japanese Patent Application Kokai Nos. SHO-55-27281 and SHO-55-27282, Asai et al teaches that the rise in temperature of the heater and the subsequent cooling speed should be as rapid as possible. The only fixed quantity mentioned however is an extremely long pulse of 100 μS.
In order to increase the frequency or ejections and provide stable ejection at the same time, boiling must be started as quickly as possible after application of the energy pulse to the thermal resistor and also the expanded bubble must be caused to disappear as rapidly as possible. Conventional technology requires that thin film resistors include a two-layer protective coating. Such thin film resistors require at least 3 μS from after start of application of the energy pulse to when the film boiling begins. Even naked thin film thermal resistors with no protective layers, which are unreliable and impractical, require at least 4 μS to generate bubbles in ethanol. Bubbles require 30 μS or more to disappear from start of the pulse application with thin film thermal resistors with two-layer protection coverings. Bubbles generated by naked thermal resistors in ethanol require 20 μS or more to disappear. Secondary bubbles are also always generated. Secondary generation of bubbles increases the time required for bubbles to disappear, thereby interfering with efforts to increase the frequency of ejections. A large amount of energy, that is, about 17 μJ/50×50 μm 2 or more, is required to start boiling with film thermal resistors with two-layer protective coverings. Although details will be explained later in the embodiment of this application, only several μJ/50×50 μm 2 or less of energy are required to start boiling by a protection-layerless thin film thermal resistor. Therefore, almost all of the energy applied to conventional heaters is used to heat the substrate. For this reason, the surface of the heater is hot while the bubble is vanishing. This is a major source of secondary bubble generation. Heating of the substrate is brought about by the material from which the ink channel is produced and the temperature of the ink. This is a source of unstable ink ejection.
SUMMARY OF THE INVENTION
It is an objective of the present invention to provide stable ink ejection and an increased frequency by reducing the necessary boiling start time, increasing the speed at which nucleated bubbles grow into a bubble film, preventing generation of secondary bubbles, and reducing the bubble disappearance time. The present invention also allows great reductions in the energy required to start boiling and allows production of an ink ejection recorder with high reliability, high speed, and high thermal efficiency.
An ink ejection recording device according to the present invention includes an ink channel filled with ink and a nozzle which brings the ink channel into fluid connection with the outside atmosphere. A thermal resistor is formed in the ink channel near the nozzle. The thermal resistor has no protective layers as described in Japanese Patent Application Kokai Nos. HEI-04-347150 and HEI-05-68257. The thermal resistor can be driven with an extremely short pulse of voltage because it has no protective layers. Despite having no protective layers, the thermal resistor is highly reliable. By applying a pulse of voltage that is 3 μS or shorter to the thermal resistor, the ink in contact with the thermal resistor begins to boil in less than 2 μS after start of application of the voltage pulse to the thermal resistor. The ink in contact with the thermal resistor is rapidly vaporized by subcool boiling, which is caused by swing nucleation. An expanding bubble is formed as a result. The expansion of the bubble ejects a droplet of ink from the nozzle. The bubble disappears within 11 μS after start of application of the voltage pulse without generation of secondary bubbles. Only 4 μJ/50×50 μm 2 worth of energy is required to generate a bubble.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become more apparent from reading the following description of the preferred embodiment taken in connection with the accompanying drawings in which:
FIG. 1 is a graphical representation of the boiling characteristic curve of water;
FIG. 2 schematically shows temporal changes from generation to disappearance of a bubble generated in ethanol using a conventional thermal resistor;
FIG. 3 shows a graphical representation of temporal changes in radius of the bubbles generated using a conventional thermal resistor;
FIG. 4 shows top and cross-sectional views of a thin film thermal resistor according to the present invention;
FIG. 5 schematically shows temporal changes from generation to disappearance of a bubble generated in water by pulse heating by the thermal resistor shown in FIG. 4;
FIG. 6 is a graphical representation showing a relationship between energy level and pulse duration applied to the thermal resistor shown in FIG. 4 to induction of swing nucleation (solid line) and single bubble generation region (dash line); and
FIG. 7 is a cross-sectional view showing a print head according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An ink jet printer according to a preferred embodiment of the present invention will be described while referring to the accompanying drawings wherein like parts and components are designated by the same reference numerals to avoid duplicating description.
FIG. 4 shows planar and cross-sectional views of a highly reliable protection-layerless thin film thermal resistor as described in co-pending U.S. application Ser. No. 08/172,825 filed Dec. 27, 1993. In this protection-layerless thin film thermal resistor, an SiO 2 layer of 2 μm thickness is formed on an Si substrate of 400 μm thickness, and a thin film thermal resistor 3 of 0.1 μm thickness is formed on the SiO 2 layer 2. Conductors 4 and 5 each being 0.1 μm in thickness are formed on the thin film thermal resistor 3. In this example, the thin film thermal resistor 3 is made from a Cr--Si--SiO alloy thin film resistor and the conductors 4 and 5 are made from nickel (Ni). However, the film thermal resistor 3 could be made from Ta--Si--SiO alloy in lieu of Cr--Si--SiO alloy, and the conductor material could be tungsten (W) or tantalum (Ta). Refer to Japanese Patent Application Kokai No. SHO-58-84401 in regards to the use of Cr--Si--SiO alloy thin film resistor, and refer to Japanese Patent Application Kokai No. SHO-57-61582 in regards to the use of Ta--Si--SiO alloy thin film resistor. The resistance of the resistor 2 is about 1 KΩ.
In one experiment for the present application, bubbles were generated by applying a pulse of voltage to the protection-layerless thin film thermal resistor in water. Images of the generation and disappearance of the bubbles were taken using a strobe light with a pulse time of about 1 μS. Results observed from these images will be explained below.
In another experiment for the present application, an ink channel was formed on the protection-layerless thin film thermal resistor. The ink channel was filled with ink. It will be explained later that the same results as obtained with water were obtained with ink.
For still another experiment, a multi-nozzle type ink jet printer head was formed from with a plurality of the ink channels described in the preceding paragraph. Ink droplets were continuously ejected from the head. An explanation will be provided of the recording characteristics of the head.
Bubbles are generated in water applied to the surface of the substrate 1 by application of a 1 μS thermal pulse having an applied energy of 2.5 μJ per pulse. Image were taken from the side with a VTR at about a 100 power magnification rate using a strobe light with shortest possible light pulse time of 1 μS. An example of the results are shown in FIG. 5. The time indicate the number of μS after start of the thermal pulse. Images taken when the applied energy was increased two to three times higher all appeared the same as shown in FIG. 5. Although generation of the bubble might actually have started earlier because of increased applied energy, the difference is difficult to discern with a magnification rate and pulse time used. Although no increase in the start of bubble generation could be measured under these conditions, it is clear that boiling began within 1 μS from the start of the thermal pulse.
As can be seen in FIG. 5, the generated bubble reached its maximum volume (negative pressure) and height (about 30 μm) within about 3 μS after start of the thermal pulse. About 5 μS later, the bubble vanishes with no generation of secondary bubbles. That is, by the time the bubble vanished, the surface of the thermal resistor had cooled to near room temperature. Energy produced when a bubble of this volume vanishes is insufficient to cause cavitation. Excessive heating of the ink is avoided and heat efficiency is improved. The temperature of the ink is stabilized, which in turns stabilizes the viscosity of the ink, thereby improving stability of ink ejection conditions. Coagulation of ink to the heater surface is prevented.
The average speed of the temperature increase produced by the thin film thermal resistor according to the present invention is, for example, 3×10 8 ° C./sec (350° C.-25° C./1 μS, assuming room temperature is 25° C.). This exceeds the above-described maximum value of 0.7×10 8 ° C./sec for average speed of temperature increase attainable using conventional technology. Although the power applied to the heater is large, i.e., 1×10 9 W/cm 2 , considering that 70 to 80% of this goes to the substrate as heat flux, this matches the conditions for swing nucleation observed by Iida et al (page 335 of the Collection of Presentations from the 27th Japan Thermal Transmission Symposium 1990-5). Furthermore, a bubble film about 5 to 10 μm high is formed on the surface of the thermal resistor about 1 μS after pulse heating is started. The speed at which the bubble grows is faster than the growth speed under the conditions for swing nucleation observed by Iida et al. That i, from these results, the bubble shown in FIG. 5 is generated by swing nucleation induced boiling.
The average speed at which the bubbles expanded (i.e., (dv/dt)/v) can be determined from FIG. 5 as 4×10 5 /S, a much faster average speed than disclosed in Japanese Patent Application Kokai No. SHO-55-161665. This value remained constant, even when the duration of the applied pulse was increased to 2 or even 4 μS, which is also different from the data disclosed in Japanese Patent Application Kokai No. SHO-55-161665. The difference in speeds of bubble expansion probably appears because swing nucleation produces a much faster average speed of temperature increase than does spontaneous nucleation.
All factors must be taken into account when setting the duration of the thermal pulse. For example, heat efficiency is greatly improved when the thermal pulse is shorter than 1 μS. However, the time at which swing nucleation starts increases to at best only 0.5 μS after start of the heat pulse. These benefits are small considering the time from application of the pulse to when the bubble disappears (about 8 μS in FIG. 20 and the time required for the meniscus to recover after ink is ejected (several 10s or 100s μS). Additionally, the power (applied voltage) must be increased to compensate for the short duration of the thermal pulse, which can be disadvantageous. A thermal pulse with duration of more than 1 μS risks generation of secondary bubbles and a drop in heat efficiency. The maximum duration of the thermal pulse is probably 3 μS. This would translated into boiling start time of 2 μS after start of the pulse.
As can be seen in FIG. 5, no secondary bubbles are generated in bubble generation according to the present invention. Therefore, the time required for a bubble to totally disappear is shortened. Ink ejection is stabilized and the ejection cycle can be reduced so that high speed ejection is possible.
In the conventional bubble generation shown in FIG. 2, wherein a bubble was generated in ethanol, 12 μS elapsed between when the bubble was at its maximum volume (that is, at the 8 μS point) to when the bubble disappeared entirely. In water, as shown in FIG. 3, 20 μS or more was necessary. Generation of secondary bubbles clearly causes the need for such long disappearance times (that is, time required for a bubble to go from its maximum size to complete disappearance). Asai et al (1986) explains this long disappearance time as being caused by bubble rebound phenomenon, which is very similar to cavitation damage.
The present invention confirmed generation of secondary bubbles using a heater from a Hewlett Packard ink jet printer (Model No. JP51626A). The disappearance time was about 10 μS. However, the present inventors have determined that this generation of secondary bubbles is not cavitation-like rebound as Asai et al stresses, but is caused simply by the heater temperature not cooling sufficiently during the disappearance time. If secondary bubbles are generated by a hot heater surface, removing this cause should prevent generation of secondary bubbles and reduce disappearance time.
The present inventors performed tests to confirm this. A protection-layerless thin film thermal resistor shown in FIG. 4 was produced. The thin film thermal resistor was energized in water at various energy levels and for various durations of time. The generation and disappearance of the resultant bubbles were observed using a strobe light. The results of the test are shown in FIG. 6. The solid line indicates the limit of the range at which swing formation occurred. The broken line indicates the limit of the range at which generation of secondary bubbles are observed. The region labeled "single bubble region" in FIG. 6 is where a single bubble could be stably and repeatedly generated. The disappearance time was constantly about 5 μS throughout the single bubble region. Stable repetitive generation of bubbles without generating secondary bubbles was possible in a sufficiently broad range of drive conditions.
It is clear that secondary bubbles are generated because the heater does not cool quickly enough and remains hot enough to generate bubbles. Therefore the disappearance time required for a bubble to disappear without generation of secondary bubbles depends on the characteristics of the liquid in which the bubble is generated, not on the drive conditions of the thermal resistor. In water, the disappearance time was constant at about 5 μS. These results were basically repeated in tests using water based ink.
In the present invention, the ripple effect greatly shortens the time required for heating and greatly decreases the amount of ink that burns onto the surface of the heater. This increases the life of the head to the point where head replacement is unnecessary.
In the present invention, the duration of the thermal pulse is set to 3 μS or less so that the generation of secondary bubbles is effectively prevented. Additionally, the disappearance time is about 8 μS, which is a great improvement over conventional technology. Swing nucleation allows a bubble to disappear in 10 to 11 μS or less after start of the voltage pulse, which is approximately 1/2 to 1/3 the time required with conventional technology. As is clearly shown in FIG. 6, the energy required to stably generate single bubbles is 4 μJ/50×50 μm 2 or less, which is 1/5 to 1/10 the amount of energy required for conventional technology.
A single nozzle head was produced to observe the above described effects. To produce the observation head, a channel with width of 60 μm and height of 40 μm was provided to the substrate 1 shown in FIG. 4. The single nozzle with a diameter of about 45 μm was provided perpendicular to the channel and to the surface of the thermal resistor at a position centered on the thermal resistor. Images were taken of generation and disappearance of bubbles from a thin side wall using a strobe light. Results were as predicted. The shape of the bubble was somewhat different because the channel formed boundaries for the liquid. However, this channel will not greatly effect generation and disappearance of bubbles.
Tests and results of the tests regarding generation and disappearance of bubbles when a protection-layerless thin film thermal resistor is pulse heated are described in detail above. The time required to generate a bubble and time required for the bubble to disappear are greatly reduced. This contributes greatly to increasing the repetition frequency of stable ejection of ink. The amount of energy needed to eject ink is reduced by an order of magnitude as mentioned above. This shows that almost no energy is consumed in heating the channel material or ink. The temperature of ink in the head need not be maintained at any particular level. Also, because the amount of ink that burns and becomes stuck to the surface of the heater is greatly reduced, the life and reliability of the head are greatly increased.
To summarize, it is desirable that the total amount of electric power applied to the thermal resistor, the thermal flux applied to ink, and the speed of temperature increase in ink (STI) be set as indicated in the table below in relation to the duration of a pulse of voltage (DPV) applied to the thermal resistor which is set to 3 μs, 2 μs and 1 μs.
______________________________________DPV Total Power Thermal Flux STI(μs) (W/m.sup.2) (W/m.sup.2) (°C./s)______________________________________3 4 × 10.sup.8 1 × 10.sup.8 1.1 × 10.sup.82 5.6 × 10.sup.8 1.4 × 10.sup.8 1.6 × 10.sup.81 8 × 10.sup.8 2 × 10.sup.8 3 × 10.sup.8______________________________________
The total electric power applied to the heater can be computed by dividing the applied energy with by the duration of pulse voltage. The heat flux applied to ink is computed on the assumption that the heat flux applied to the ink is one quarter (1/4) of the total amount of power applied to the heater based on the previous disclosure that 70 to 80% of power applied to the heater goes to the substrate as heat flux. The speed of temperature increase in ink is obtained as per a unit of time, second.
From the above table, various parameters to produce bubbles by subcool boiling caused by swing nucleation are set as follows according to the present invention. The pulse of voltage applied to the heater has a duration equal to or less than 3 μsecond. Speed of temperature increase in the ink is set equal to or greater than 1.1×10 8 ° C./sec, and heat flux applied to the ink by the heater is set equal to or greater than 1×10 8 W/m 2 .
Next, the multi-nozzle type ink jet printer head shown in FIG. 7 was produced using the thin film thermal resistor shown in FIG. 4. First, a Cr--Si--SiO-- alloy thin film thermal resistor 3 and an integrated circuit (IC) 6 for driving the thermal resistor 3 were formed on the surface of a silicon substrate 1. For driving the head, a nickel common wire conductor 4, individual nickel wire conductors 5, drive power wire conductors 7, and signal wire conductors 8 were formed to the substrate 1. An ink channel plate 15 was formed with ink nozzles 9, individual ink channels 10, and a common ink channel 11. The ink channel plate 15 was mounted to the silicon substrate 1 to form a monolithic large scale integrated (LSI) head. The monolithic LSI head was die bonded to a frame 16. Ink was supplied to the ink channels 11 from the ink channel 14 in the frame 16 and through connection aperture 13 and the common ink channel 12 in the silicon substrate 1. Ink was ejected from one ink nozzle 9 after another. In this example, the Cr--Si--SiO alloy thin film thermal resistor 3 was formed to 45 μm by 45 μm, the ink channel nozzle was formed to a diameter of 45 μm, and the individual ink channels were formed with a width of about 50 μm, a height of 35 μm, and a length of 150 μm.
A plurality of ink nozzles 9 were provided aligned at a pitch of about 7 μm (360 dpi) in the direction perpendicular to the surface of the sheet one which FIG. 7 is drawn. Heads of various sizes can be produced as described in Japanese Patent Application Kokai No. HEI-05-90123. For example, a small serial scanning type head with total number of, for example, 64 nozzles can be produced or a line head for A4 size paper or larger with two rows of 1,512 nozzles, for a total of 3,024 nozzles, can be produced.
Tests were performed to determine the recording characteristics of the head. The maximum frequency at which ejection could be stably performed was determined to be 8 KHz. As a comparison, a head produced by Hewlett-Packard with the same configuration as shown in FIG. 7, but wherein the thin film thermal resistors are covered with a two-layer protective covering, has a maximum frequency of about 6 kHz. The head according to the present invention required between 2.0 to 2.5 μJ/droplet for ejection, which can be over an order of magnitude less than the 17 to 30 μJ/droplet required for ejection by conventional heads. The head according to the present invention showed stable ejection even after 100 million or more ejections. The same results were obtained in a print head according to the present invention wherein the direction of ejection is parallel with the surface of the heater.
According to the present invention, by driving a protection-layerless heater with only a short pulse of voltage, ink can be heated at an extremely fast average speed of temperature increase. Therefore, the time between when the pulse is applied to when the bubble disappears is 11 μS or less. This is about 1/3 the time for conventional technology. The print speed (ejection frequency) of the thermal ink jet print head according to the present invention is 30% or greater than conventional heads. About one order of magnitude less power is consumed.
While the invention has been described in detail with reference to a specific embodiment thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the attached claims.
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An ink ejection printer includes an ink channel filled with ink, a nozzle which brings the ink channel into fluid connection with an outside atmosphere, and a thermal resistor formed in the ink channel near the nozzle. The thermal resistor received a pulse of voltage, whereupon the thermal resistor rapidly heats so that a portion of the ink in the ink channel is rapidly vaporized by subcool boiling, which is caused by swing nucleation, to produce a bubble, expansion of the bubble ejecting an ink droplet from the nozzle. With the thermal resistor, boiling starts within 2 μS after application of the pulse of voltage begins. The pulse of voltage is applied to the thermal resistor for a duration of 3 μS or less. The bubble generated by application of the pulse of voltage to the thermal resistor disappears without the thermal resistor generating secondary bubbles. The bubble generated by application of the pulse of voltage of the thermal resistor disappears within 11 μS after application of the pulse. Energy required to generate the bubble is 4 μJ/50×50 μm 2 or less.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to coating materials, such as for example laminar coating materials which can be used in the building and furnishing sector, in particular for the production of floorings.
[0003] 2. Description of the Related Art
[0004] The wide variety of coating materials of this type so far available may be reduced to three fundamental categories.
[0005] The solution that perhaps dates back the furthest is the coating material commonly referred to as linoleum. The corresponding production technique basically envisages adding filler materials such as sawdust and cork dust, mineral fillers, pigments and other additives to linseed oil so as to obtain a so-called linoleum paste. This undergoes rolling in order to form sheets, which then undergo a so-called “maturing” step, which has a duration of some dozens of days and is essentially aimed at achieving a consolidation of the linoleum sheet sufficient to enable its further manipulation and treatment (for example, so as to enable its winding into rolls for subsequent laying).
[0006] Although this solution has a long history, it occupies quite a modest market share, both on account of the disadvantages linked to the intrinsic slowness of the maturing process and because, in the steps subsequent to laying, the linoleum flooring tends to release into the environment an intense and characteristic odour linked to the presence of the linseed oil.
[0007] A very substantial slice of the market of coatings and floorings is represented by synthetic plastic materials. One of the materials most widely used for making these coatings, which at present may have a contained cost, is represented by polyvinyl chloride (PVC). Irrespective of any other consideration, these floorings, and in particular the PVC-based ones, tend to be viewed with less favour on account of the substances (for example, chlorine) which may be released by the coating and which also have an unpleasant smell.
[0008] Over the last few years, rubber-based floorings have encountered particular favour. These floorings enable a combination of excellent characteristics of wear (for example, as regards resistance to mechanical stresses and to aggressive chemical agents, as well as to burns) with the possibility of creating coatings and floorings having a particularly agreeable aesthetic appearance (for example, with general marbleization effects or effects of seeding of granules of various colours). Examples of this prior art are described in the documents EP-A-0 968 804 and EP-A-1 020 282.
[0009] Even though to a much smaller extent as compared to the other types of coatings considered previously, also rubber coatings tend to have a rather strong and unpleasant smell, above all immediately following upon laying and on account of the substances used for vulcanizing the rubber.
[0010] Over the years there has been no shortage of attempts to merge features characteristic of the various production techniques considered previously. For example, described in the document EP-A-0 385 053 are linoleum coatings with rubber fillers, the main purpose here being to enable exploitation of the process of vulcanizing rubber in order to provide a linoleum coating which can be handled and transferred to the site where it is to be laid in a much shorter time as compared to the characteristic time required for maturing linoleum floorings of a traditional type.
BRIEF SUMMARY OF THE INVENTION
[0011] The purpose of the present invention is to provide a coating material which can be used, for example, as flooring and is able to combine the majority of the qualities of coating materials of a traditional type, without presenting the drawbacks thereof.
[0012] According to the present invention, the above purpose is achieved thanks to a coating material which has the characteristics referred to specifically in
[0013] the ensuing claims. The invention relates also to the corresponding process of fabrication, as well as to a corresponding intermediate product.
[0014] The coating material described in what follows is able to offer, as regards the characteristics of resistance to environmental agents (mechanical stresses and attack by chemical agents, resistance to burns, etc.), characteristics that are altogether equivalent and, at least in some cases, decidedly superior both to those of plastic coatings and to those of rubber coatings (hence, from this point of view, features that are far superior to those of linoleum coatings).
[0015] As regards aesthetic characteristics, the solution described herein enables production of coating materials with chromatic features extending over a practically infinite range, with an extremely wide range of choice also as regards the marbleization effects.
[0016] The results of the foregoing process, at least as emerges from the experiments so far conducted by the present applicant, are in many cases qualitatively superior to the results that can be commonly achieved in the case of coatings made of plastic material and of rubber.
[0017] Furthermore, the solution described herein has the important advantage afforded by the fact that the finished product is practically odourless. The product can consequently be used without problems of any sort even in environments, such as, hospitals, in which appreciable olfactory effects, albeit in themselves not unpleasant, are however, to be avoided.
[0018] The above advantage is achieved in the framework of a process of fabrication which, whether as regards efficiency and economy of production or as regards production times, does not involve any additional burdens over and above those of techniques at present widely used in the industry.
[0019] As will be illustrated in greater depth in what follows, the solution described herein envisages adding to a polyolefin matrix (for example, polyethylene) a dispersed phase of particulate material (the so-called “powder”) of vulcanized rubber.
[0020] Materials based upon this combination are in themselves well known to the art, as is witnessed by the numerous documents, such as U.S. Pat. No. 4,130,535 and U.S. Pat. No. 4,311,628.
[0021] The solutions described in these prior documents aim, however, at creating the so-called “thermoplastic elastomers”, i.e., materials that can be used for technological applications, for example in the automobile sector.
[0022] The materials obtained in these documents of the known art are suitable for applications typical of elastomers, such as rubber (for example, weather-proofing for windows of motor vehicles, production of hoses for conveying fluids even at high temperatures and pressures, etc.).
[0023] For this purpose, the above known solutions emphasize the importance linked to the fact that the elastomer (rubber) particles constitute a phase finely dispersed in the polyolefin matrix with a typical grain size of the elastomer particles that is amply sub-millimetric. For example, U.S. Pat. No. 4,130,535 indicates as typical size of the rubber particles constituting the dispersed elastomer phase ones in the region of 50 micron.
[0024] Persons skilled in the sector may then appreciate that the hypothetical transposition of said known teachings to the context of the present invention comes up against the recognition of the fact that sub-millimetric grain sizes such as the ones referred to previously would in effect be non-appreciable from the visual standpoint. This latter aspect is clearly of primary importance in the application to the sector of coatings to which the present invention refers.
BRIEF DESCRIPTION OF THE DRAWING
[0025] The invention will now be described, purely by way of non-limiting example, with reference to the following figures:
[0026] FIG. 1 represents, in the form of a functional block diagram, a preferred embodiment of a process for the production of the material according to the invention.
[0027] FIG. 2 represents product made in 110 , 112 or 114 FIG. 1 , according to the invention.
[0028] FIG. 3 represents a product as made in step 118 of FIG. 1 .
[0029] FIG. 4 represents a proposed final product as made in step 122 of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0030] By way of introduction, it should be recalled that each of the operating steps described in what follows, as well as the equipment that enables implementation thereof, are—taken in themselves—widely known to the prior art.
[0031] This fact thus renders superfluous any detailed description herein of said operating steps and of the corresponding equipment.
[0032] In the specific case, the process illustrated in FIG. 1 is designed to provide a coating which can be used, for example, as flooring.
[0033] In particular, it will be assumed that the aim is to provide a coating with an overall chromatic effect of the type commonly referred to as “marbleized effect”. This is thus a coating which presents an appearance somewhat similar to that of a marble with a fine granular structure or, to be perhaps more precise, may be likened to the appearance of granite. Added to this is, of course, the possibility of varying the chromatic characteristics of the coating over a practically infinite range.
[0034] Specifically, the coating to which the present description refers comprises a polyolefin matrix (for example polyethylene) having a first colouring. As used herein, the term “colouring” also comprises a material having a neutral and/or substantially transparent colouring.
[0035] The overall chromatic effect of the coating is dictated by the presence, in the polyolefin matrix, of granular rubber material (the so-called powder) having a colouring which contrasts with that of the polyethylene matrix.
[0036] In what follows, it will be assumed, purely by way of example, that there is available vulcanized rubber material of three different colourings such as black, light grey and dark grey.
[0037] The individual granular material may in turn be made up of granules which have, instead of a single colouring, different colourings, obtained for example by the presence, in the individual granule, of portions which have different colourings. Granular materials, in particular rubber materials, which have said marbleized appearance and can be used for example for the so-called “seeding” on a substrate of rubber flooring, are well known to the prior art.
[0038] Of course, the fact that the example illustrated herein envisages the use of three different types of granular rubber material must not be interpreted as in any way limiting the possibility of using granular materials in a smaller number (for example, it is possible to envisage the presence of just one type of granular material) or a greater number (for example four or more) as compared to the example provided herein.
[0039] The currently preferred embodiment envisages that, starting from each starting granular material such as a powder, it is possible to obtain an intermediate material made up of a granular material the granules of which already combine within them both the polyolefin matrix and the particulate elastomer material, such as a rubber.
[0040] In the block diagram represented in FIG. 1 the references 100 , 102 and 104 designate precisely-three particulate elastomer materials, such as vulcanized rubber with different chromatic characteristics. For example, as has already been said previously, these may be materials which have a prevalent colouring of black ( 100 ), light grey ( 102 ) and dark grey ( 104 ).
[0041] The typical size of the particles of the materials 100 , 102 , 104 are usually comprised between 100 and 500 micron (0.1 to 0.5 mm), the aim being to ensure the visual perceptibility of the granules in the final product.
[0042] Reference to the grain sizes indicated above is to be understood in the sense that the materials 100 , 102 and 104 contain at least a fraction (and preferably, a substantial fraction) of particles with dimensions comprised between 100 and 500 micron.
[0043] On the other hand, said materials may very well comprise also particles of smaller size. The experiments conducted by the present applicant show that these particles of smaller size play a certain role in the overall chromatic result, creating, in the final coating, portions of material which have a colouring that is intermediate between the colourings of the various starting components.
[0044] Once again in the attached figure, the reference number 106 designates a granular polyolefin material. This may, for example, be polyethylene, of the currently industrially available low-density type.
[0045] Possibly, the polyolefin matrix may be made up of a blend of different polyolefins (for example, polyethylene and polypropylene), with the possible further use, either entirely or in part, of recycled polyolefin material.
[0046] The reference numbers 108 and 109 designate treatment steps applied, in an identical or substantially identical way, to all three of the materials 100 , 102 and 104 .
[0047] In particular, the step designated by 108 is a mixing step, in which the elastomer material 100 , 102 , 104 is mixed with the polyolefin granules 106 with operations of mixing conducted typically at temperatures in the region of 160° C. to 180° C., typically in mixing equipment of the Banbury or continuous-mixer type.
[0048] After mixing at temperature, the mix thus obtained is left to cool and subjected to granulation by extrusion.
[0049] The above treatment step is designated by the reference number 109 and leads, as final result, to the production of three “intermediate” granular materials 110 , 112 and 114 obtained starting from the polyolefin mixture (typically between 5 wt % and 40 wt %, preferably 20 wt %) and the elastomer material 100 , 102 and 104 (with weight percentage complementary to that indicated for the polyolefin mixture).
[0050] FIG. 2 shows two examples of products 10 and 12 at the stage following the first granulation. Product 10 has color A and product B has color B, each represented by the different cross-sectioning and particle sizes.
[0051] The size of the granules of the materials 110 , 112 and 114 are typically in the region of 1-4 mm. This factor is not considered to be particularly critical.
[0052] Each of the intermediate granular materials 110 , 112 and 114 (and any similar material that may be obtained by mixing polyolefin and elastomer materials according to the criteria described previously) constitutes one of the “colours” of a wide range of colours that can be used for the production of the final product.
[0053] Intermediate products, such as the products designated by 110 , 112 and 114 , can then be stocked for subsequent use. Added to the foregoing advantage is the widest possibility of mixing according to the chromatic result that is desired for the final product, both as regards the number and as regards the relative proportions of the intermediate granular products used.
[0054] The experiments conducted by the present applicant show that it is in fact possible to obtain a final product containing particulate materials of vulcanized elastomer with different chromatic features simply by mixing these materials having different chromatic characteristics with the polyolefin material of the matrix in a single operation.
[0055] The process of mixing in two steps referred to in FIG. 1 (with an initial step in which the individual elastomer material is mixed with the polyolefin to produce an intermediate granular material) proves to be amply preferential as regards the quality of the final product, above all considering the fact that the two-step step process described herein affords the major advantage of preventing an excessively intimate mixing of the various particulate materials 100 , 102 and 104 .
[0056] In this way, the various materials in question contribute to the final chromatic effect of the flooring, each, at the same time, maintaining a precise individuality of its own. The result thus achieved may basically be defined as a sort of greater “luminosity” of the coating obtained as compared to the solutions in which particulate materials of different colouring are directly mixed together along with the polyolefin.
[0057] Albeit without wishing to be tied down to any specific theory in this regard, the present applicant has good reasons to believe that the steps designated by 108 and 109 in the annexed drawings lead to bringing about, in the intermediate granular product 110 , 112 , 114 , an at least partial “coating” or “encapsulation” of each particle of elastomer material with a polyolefin layer.
[0058] The above polyolefin layer to a certain extent isolates the particle of elastomer material during the successive steps of treatment, so preventing an excessively intimate mixing of the particles of elastomer in the subsequent step, designated by 116 in the annexed block diagram, in which the various intermediate granular materials 110 , 112 , 114 (the number of which, it is once again recalled, may be any whatsoever) undergo mixing.
[0059] This is typically a mixing operation obtained in an extruder starting from relative percentages of the various intermediate granular materials 110 , 112 and 114 chosen according to the final characteristics desired for the product.
[0060] By way of example (but it is emphasized that this is just one example amongst the infinite possibilities), for the mixing step 116 there may be used 10% of intermediate granular material 110 , 30% of intermediate granular material 112 , and 60% of intermediate granular material 114 . In another example, it may be 40%, 20% and 40%, while in yet another example, it may be 70%, 30% and 0%.
[0061] The final mixed material obtained as the result of step 116 undergoes, in a step designated by 118 , an operation of granulation, which precedes a step in which the granular material obtained as the result of step 118 is “seeded” on a substrate, then to undergo rolling in a step designated by 122 . FIG. 3 shows the product 18 as it exists in step 118 .
[0062] In a preferred way, the said step of rolling is not conducted using a calander, but rather using an isostatic press. The laminar material obtained by means of isostatic pressing usually has the advantage of being absolutely isotropic, i.e., free from any directional phenomena linked to possible stretching of the granules. FIG. 4 shows a final product 20 that is a laminate of substrate 19 and mixed color product 18 . The substrate 19 can be acceptable flooring substrate, such as a PVC, a VCT (vinyl composite tile) resin composite, a hard rubber, or ceramic, or other known floor bases.
[0063] Finally, the reference number 124 designates one or more processing steps in which the rolled material is, for example, smoothed or painted (these are, for the most part, altogether optional operations), then to be sent on for packaging, where, for example, it is wrapped in rolls or other forms of packaging that may be convenient for laying.
[0064] The table provided in what follows is aimed at highlighting, with reference to some measurement methods that form the subject of well-known reference standards, which are familiar to persons skilled in the sector, the improvement that can be appreciated from direct comparison of various characteristics of a resilient rubber flooring and a flooring made according to the solution described herein.
New Property Method Unit of measure Rubber Product Thickness UNI EN 428 mm 2.0 2.0 Hardness ISO 7619 Shore TO 90 94 Residual im- UNI EN 433 mm <0.11 <0.05 pression Wear resistance ISO 4649 mm 3 160- 50-80 Method A 180 Dimensional stab- UNI EN 434 % <0.4 <0.1 ility
[0065] It will moreover be appreciated that the solution described herein is likewise characterized by the ample possibility of recycling the material, above all within the production cycle, and/or by the generalized type of elastomers that can be used in the vulcanized rubber powder: natural rubber NR, SBR, EPM, EPDM, IR, BR, CR and NBR.
[0066] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.
[0067] Of course, without prejudice the principle of the invention, the details of production and the embodiments may widely vary with respect to what is described and illustrated herein, without thereby departing from the scope of the present invention as defined in the annexed claims.
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A laminar coating material, for example for use as flooring, comprises: a polyolefin matrix having a first colouring; and a phase of particulate elastomer material, such as vulcanized rubber, dispersed in the polyolefin matrix and comprising particles of at least one second colouring, which contrasts with the colouring of the polyolefin matrix. Preferably, the particulate elastomer material in question is in turn obtained starting from a plurality of intermediate mixes, each comprising a polyolefin matrix having a first colouring, in which there is dispersed a respective particulate phase comprising particles of a respective second colouring. The respective second colouring is different for each intermediate mix and contrasts with the aforesaid first colouring. The intermediate mixes are mixed together so as to form a mixture used for obtaining the final material, preferably by means of granulation, formation of a bed of granules, and isostatic pressing of the bed thus formed.
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TECHNICAL FIELD
[0001] The present invention relates to recreational boards, such as a snowboard or wakeboard, and more particularly boot-binding mounts that can be attached to a recreational board.
BACKGROUND ART
[0002] Snowboarding is a sport which can be visually compared to skateboarding and surfing, except it is done on snow. Snowboard skiing is the legal name for snowboarding, which thereby affords snowboarding all the privileges and liabilities of alpine skiing. To snowboard, the rider stands on the board with the left or right foot forward. Both feet are directed toward the same side of the board. The feet are attached to the board via high-back or plate bindings which are non-releasable. Although there is at least one manufacturer of releasable bindings, they are not widely used.
[0003] Snowboarding has gained in popularity during the last 10 years. It was pioneered in the late 1970's by a group of individuals with credit going to Jake Burton and Tom Sims. Both individuals head snowboard manufacturers, with Burton being the largest snowboard manufacturer. The cost of snowboard equipment is comparable to ski equipment.
[0004] Major competitions utilizing snowboarding equipment are organized, involving major sponsorships, television coverage, and world-class athletes. Competitions include downhill speed runs, slalom races, half-pipe, and freestyle performances. Four major categories of snowboards have been developed and designed, including race, alpine, all-around/free-riding, and half-pipe/freestyle.
[0005] Several different types of binding systems are known in the art, as represented by the binding systems shown in U.S. Pat. Nos. 5,354,088; 5,236,216; 5,190,311; 5,044,654; 4,964,649; 4,871,337. Two types of bindings are most commonly used in snowboarding: the high-back and the plate. The high-back binding is characterized by a vertical plastic back piece which is used to apply pressure to the heel-side of the board. This binding has two straps which extend over the foot, with one strap applying pressure to the heel region and the other applying pressure to the toe region. Some high-back bindings also have a third strap (a “shin strap”) on the vertical back piece, which gives additional support and aids in toe side turns. The plate, or step-in, binding is used with a hard shell boot much like a ski binding, but it is non-releasable.
[0006] Snowboard boot bindings typically include a rotational adjustment which allows the user (i.e., the “rider”) to adjust the relative angular position of the boot binding relative to the longitudinal axis of the snowboard, thereby allowing the user to set the bindings in a position of personal comfort. For example, if a user likes to ride with the left leg forward on the snowboard, then the boot binding will typically be adjusted so that the user's foot (toes) points to the user's right relative to the longitudinal axis of the snowboard. Similarly, if a user rides with the right leg forward, the boot binding will usually be adjusted so that the toes point to the user's left. The amount of the rotational adjustment varies greatly as a function of individual preference.
[0007] For different events, the desired rotational adjustment may vary significantly. For instance, during speed runs such as Giant Slalom (GS), the snowboarder may prefer to have both feet oriented more straight ahead. For other events such as freestyle, the desired angle may be one in which the feet are oriented more perpendicular to the longitudinal axis. According to the publication “Transworld Snowboarding,” the average stances of pro riders from different snowboarding disciplines are as follows (with widths in inches, center being inches back from center, length in cm, and angles in degrees relative to the perpendicular to the longitudinal axis):
Stance Front Rear Board width angle angle Center length Notes Half-pipe 20.7″ 17 2 0.5″ back 152.5 cm some boarders use negative rear angles (duck- stance) Freeride 21.1″ 22 7 1.7″ back 170 cm Slalom 17″ 49.2 47.2 0.4″ back 156.8 cm GS 17″ 49.6 47.6 0.44″ back 164.9 cm Super G 17.16″ 49.4 47.4 0.45″ back 170.5 cm SlopeStyle 21.3″ 12 0 1″ back 152.9 cm 0 rear on all riders (also known as freestyle)
[0008] Presently, snowboard bindings cannot be rotated and locked at different angular positions without using hand tools. Bindings are secured to the board by either inserts or a retention plate. Inserts consist of a nut built into the board, with a machine screw being used to secure the binding. With the retention plate system, a sheet metal screw is used after tapping a hole into the board. It is referred to as a retention plate because a metal plate is built into the board where the board will be tapped. In use, the commercially available boot bindings are typically screwed or bolted to the board using a round disk and one of two-hole patterns: a three-hole pattern shown in U.S. Pat. No. 5,261,689 to Carpenter et al., or a four-hole pattern. Each pattern provides four different positions or settings for stance adjustment of each binding.
[0009] With either hole pattern method, the user must first remove the boot from the binding and then loosen the series of screws, typically with a screwdriver, so the binding can be rotated and repositioned at the desired angle. The screws must be retightened to lock the binding in place and the user can then reinsert the boot into the binding. Such an operation is time consuming and inconvenient for the snowboarder. It would be impractical to require a snowboarder to repeatedly perform such a field operation in a single day. This is particularly true given the high cost of ski-lift tickets and the overall desire by riders to maximize the number of runs performed during any given day.
[0010] Most people who use snowboards recreationally prefer to have the front foot positioned at a large angle (e.g. approximately 45 degrees or more) with respect to the longitudinal axis of the snowboard. After snowboarding down the slope, the user typically releases the rear boot and pushes along with the free foot to move the snowboard. Such action is similar to that provided by a skateboarder to move forward on flat surfaces, and hence is called “skating.” If enough speed can be achieved via skating, the snowboarder can “glide” by placing the rear foot on the stomp pad which is attached between the bindings. However, unlike skateboarding where both feet are free, the snowboarder's front foot is fixed at an awkward and inconvenient angle, thereby making it difficult to achieve efficient forward locomotion.
[0011] Additionally, the inconvenient angle of the user's foot poses a problem when the snowboarder mounts and dismounts the ski lift. When sitting down and extending the legs forward, the angle of the fixed foot causes the snowboard to interfere with adjacent passengers on the ski lift. This causes the snowboarder to uncomfortably twist a foot and/or leg and/or body sideways to compensate for the angle of the snowboard. This is particularly unacceptable in light of the long ride time on many ski lifts.
[0012] In recent years, the popularity of snowboarding and wakeboarding has grown at a tremendous rate. To draw more people into the sport of snowboarding, more convenient and comfortable binding systems are required. The cross-orientation of the bindings allows the rider to assume a side-forward stance, which is the necessary positioning for optimal control of the snowboard when going down the hill. While this side-forward positioning is optimal for control on the downhill run, it presents a number of problems between runs.
[0013] One solution to the problems is to provide a mechanism that will allow at least one of the bindings to be rotated from the normal transverse angular position to a toe-forward position relative to the snowboard. Then, a rider can adjust the angle before each non-snowboarding use of the snowboard. In U.S. Pat. No. 5,236,216, for example, there is shown a fastening disk that can be clamped upon a binding support plate that can be turned about a normal axis to the board. In order to change the user's foot position, the user must remove his boot from the binding, allowing him to loosen several bolts to allow the rotational position of the binding plate to be changed, then the bolts must be re-tightened. Similarly, in U.S. Pat. No. 5,261,689 to Carpenter et al., a number of bolts through a hold-down plate for a rotatable binding-support plate must be loosened and then re-tightened in order to change the binding orientation. While the aforementioned binding support systems have their advantages, they all share a major drawback in not allowing angular adjustment of bindings to be made quickly, easily, and conveniently, because they require removal of the boot from the binding in each case, and the use of tools to tighten and loosen the bolts.
[0014] U.S. Pat. Nos. 5,499,837, 5,667,237 and 5,732,959 recognize some of these problems to snowboard bindings and provide alternative locking mechanisms. However, binding mounts of these patents do not address the concern of snow and ice build-up inhibiting the proper operation fo the locking mechanism.
[0015] What is needed is a mounting assembly that provides a snowboarder, wakeboarder, or other rider the capability of rapidly and easily changing the orientation of at least one binding-attached foot from a transverse position on such a board to a foot-forward position, thereby enabling a natural position of the knee, foot, and leg during standing, walking, sitting, “skateboarding,” and other activities.
SUMMARY OF THE INVENTION
[0016] A mounting assembly for use with a board, such as a snowboard or wakeboard, includes a binding for attachment to a person's foot, a securing mechanism for securing the binding to the board at a selectable angle which is fixed when the binding is engaged with the securing mechanism, and an adjustment mechanism having a thickness which is variable so as to define a lock condition and a release condition. The adjustment mechanism is positioned so that the binding is disengaged from the securing mechanism when the adjustment mechanism is set at a first thickness that establishes the release condition, but the binding and securing mechanism are engaged when the adjustment mechanism is set at a second thickness that establishes the lock condition.
[0017] There are a number of contemplated embodiments for achieving the variable thickness for the adjustment mechanism. The embodiments may be lever based, clutch based, material-expansion based, or based generally on the use of upper and lower plates to provide an arrangement in which thickness is selectable.
[0018] In one embodiment, the binding and the securing mechanism are formed of components that are conventional to the art of snowboarding. Thus, the binding may be a boot mount having an opening with a first pattern of teeth, while the securing mechanism is a binding disk that is received within the opening. The binding disk may have a second pattern of teeth that locks with the first pattern when the binding disk is pressed into the opening. The lock condition of the adjustment mechanism causes the second pattern of teeth to enter a press-fit engagement with the first pattern. However, the release condition is one in which the binding and binding disk remain attached to the board, but are disengaged from each other, so that relative rotation between the two patterns of teeth can occur.
[0019] In one embodiment, the adjustment mechanism is comprised of first and second members that are configured to provide the selectable thickness. One or both of the first and second members may have ramped regions, with the members being configured such that relative rotation therebetween causes the change in thickness. The first member may include slots that are aligned with projections from the second member, enabling the projections to ride within the slots as one member is rotated relative to the other. In this embodiment, the adjustment mechanism may be clutch based.
[0020] An advantage of the invention is that the adjustment mechanism may be used with commercially standard bindings and binding disks. Thus, the adjustment mechanism may merely be a retrofit item. As a result of using the invention, a person is able to easily and quickly change the angle of a boot mount relative to a board without disconnecting any parts from the board. Preferably, the angular adjustments are made without the need for hand tools. Since the angle of the boot mount is easily adjusted, an increase in comfort between downhill runs by a snowboarder is achieved. Moreover, there is a reduction in the risk of harmful stress to the leg joints, ligaments and muscles of the snowboarder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a partially exploded perspective view of a binding, binding disk, spacing disk, and snowboard in accordance with the present invention.
[0022] [0022]FIG. 2 is a perspective view showing the location of a general clutch device and its change in thickness operation in accordance with one embodiment of the invention.
[0023] [0023]FIG. 3 is a perspective view of the clutch disk and the spacing disk of FIG. 2.
[0024] [0024]FIG. 4 is a bottom view of the clutch disk of FIG. 3.
[0025] [0025]FIG. 5 is a top view of the spacing disk of FIG. 3.
DETAILED DESCRIPTION
[0026] With reference to FIG. 1, a binding disk 20 is shown as being adapted to be mounted to a board 23 using screws 10 that are received in internally threaded holes 24 within the board. The binding disk is sometimes referred to as a hold-down plate. The binding disk secures a binding 21 and a spacing disk 22 in fixed positions relative to the board, when the screws 10 are tightly fastened into the internally threaded holes of the board.
[0027] The binding disk 20 and the binding 21 may be conventional components that are commercially available. For example, the two components may be identical to those described in U.S. Pat. No. 5,261,689 to Carpenter et al., which is incorporated herein by reference. The binding plate is able to enter into, but not pass through, an opening 25 within the binding. The outer edge of the binding disk is angled inwardly with downward movement, as viewed in FIG. 1. On the other hand, the edge of the opening 25 is angled outwardly with upward movement. As a result, when the binding disk is press-fit into the opening, the correspondingly sloped surfaces are mated. The sloped surfaces have upwardly extending patterns of teeth that prevent relative rotation between the binding and binding disk when the two patterns of teeth are in press-fit engagement. While the sloped surfaces and the use of teeth are described as one possible arrangement, persons skilled in the art will readily recognize that other arrangements are possible without diverging from the invention.
[0028] In accordance with the prior art, the spacing disk would not be included, so that when the binding disk 20 is fastened to the board 23 , the press-fit engagement of the two patterns of teeth will fix the angle of the binding 21 relative to the longitudinal axis of the board. However, the spacing disk 22 is not a component of prior art mounting assemblies for use with boards in which a foot binding is attached at a selectable angle. The spacing disk has a diameter that is less than that of the opening 25 in the binding. As a consequence, the normally tight mating between the binding disk and the binding is releasable. The binding can be rotated relative to the longitudinal axis of the board merely by ensuring that the spacing disk 22 is sufficiently thick to allow disengagement of the two patterns of teeth.
[0029] The difficulty with using the spacing disk 22 by itself is that the binding 21 will be able to rotate at undesired times. Thus, an adjustment mechanism is used with the spacing disk, so that the binding 21 may be selectively locked into a position in which it is in tight press-fit engagement with the binding disk 20 . This can be achieved by providing a variable thickness below the surface of the binding, so that the binding is raised and lowered on the basis of the change in thickness. Any number of lever based, clutch based, material-expansion based, or other mechanisms may be used. For example, in a material-expansion based embodiment, a compressible material having a strong expansion memory may be used to bias the binding upwardly, with the bias being overcome by hand pressure applied by a user when the angle of the binding is to be adjusted. In a simplified application, one or more wedges may be slid beneath the binding in order to lock the binding angle. Wedges may easily be fixed to the surface of the board for slidable movement.
[0030] A more sophisticated arrangement is shown in FIG. 2. In this embodiment, the variations in thickness are achieved using a clutch device 30 (i.e., clutching mechanism). The clutch device can expand and contract in thickness on the basis of movement of a handle 31 . When the thickness of the clutch device is similar to that of the spacing disk 32 , the binding 21 is forced upwardly into a secure press-fit engagement with the teeth of the binding disk 20 . On the other hand, when the thickness of the clutch device is less than that of the spacing disk, the binding is free to move downwardly and rotate relative to the binding disk. The rotation relative to the binding disk varies the angle of the binding relative to the longitudinal axis of the board 23 .
[0031] Referring now to FIGS. 2, 3, 4 and 5 , the illustrated clutch device 30 includes a lower plate 40 and an upper plate 41 . As best seen in FIG. 3, the spacing disk 32 may be integrated into the lower plate 40 . The spacing disk includes six elongated openings 50 , where the arrangement of the openings is selected to allow the clutch device to be used with any of the conventional hole patterns within commercially available boards. For example, the clutch device may be used with either the three-hole pattern on the board of FIG. 2 or with the four-hole pattern that is also commonly used with snowboards.
[0032] The upper plate 41 includes the handle 31 and a central opening 52 having a diameter slightly greater than the diameter of the spacing disk 32 of the lower plate 40 . Thus, the spacing disk will pass freely through the central opening 52 in the upper plate, so that the upper plate can be rotated relative to the lower plate.
[0033] The upper surface of the lower plate 40 is formed of a repeating series of a lower flat region 54 , a ramped region 56 , and an upper flat region 58 . A slot 60 extends through each series of the three regions. The slot begins at the start of a lower flat region 54 , extends completely through the ramped region 56 , and partially passes through the upper flat region 58 . The series of three regions is not critical to the invention, since other arrangements in which thickness is varied can be substituted.
[0034] [0034]FIG. 4 is a view of the bottom surface of the upper plate 41 . In the same manner as the lower plate 40 , the surface of the upper plate is a repeating series of a lowermost flat region 62 (“lowermost” when the plate is viewed in the orientation of FIGS. 2 and 3), a ramped region 64 , and an uppermost flat region 66 . A downwardly extending projection 68 is positioned at the beginning of each lowermost flat region 62 . The regions 62 , 64 and 66 are not visible in the perspective view of FIG. 3, since the upper plate includes a circumferential lip 70 that retards the entrance of snow and ice into the area between the two plates 40 and 41 .
[0035] In operation, the lower plate 40 is locked in position by the passage of the screws 10 through the openings 50 in the spacing disk 32 . However, the upper plate 41 is able to rotate relative to the lower plate. A user may grip the handle 31 and move the upper plate between a locked position and a release position. In the embodiment illustrated in FIGS. 2 and 3, the release position is one in which the upper plate 41 is at its extreme counterclockwise location, thereby aligning the lowermost flat regions 62 of the upper plate with the lower flat regions 54 of the lower plate. Then, as the upper plate is rotated in a clockwise direction, the projections 68 of FIG. 4 will ride within the slots 60 of FIG. 5 and the two sets of ramped regions 56 and 64 will cause an increase in the thickness of the clutch device 30 . The thickness will continue to increase until the flat regions 62 of the upper plate 41 rest on the flat regions 58 of the lower plate.
[0036] In the minimum-thickness position of the clutch device 30 , the binding 21 is able to be lowered sufficiently to release the press-fit engagement with the binding disk 20 . As a result, the binding 21 can be rotated while all of the components remain attached to the board 23 . Then, when the upper plate 41 of the clutch device 30 is rotated to its extreme clockwise position, the clutch device will have its maximum thickness, thereby pressing the binding into a tight engagement with the binding disk 20 .
[0037] It should be noted that the present invention may be used with existing mounting holes 24 in the board 23 and may be used with the commercially available bindings 21 and binding disks 20 . Other than the two plates 40 and 41 , no additional screws or components are required. This results in several significant advantages, including (1) simplicity of design and manufacturing, (2) simplicity in parts and functions, providing reliable operation in snow and ice conditions, (3) a manageable increase in thickness, which results in the binding 21 being mounted very nearly directly to the board 23 , and (4) any difficulties in operation of the invention will not result in the binding disconnecting from the board. On the other hand, the clutch device may be integrated with a binding, so that the assembly of a binding and the device is purchased as a unit.
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A mounting assembly in accordance with the invention provides rotational adjustment of a board binding, such as a binding of a snowboard, wakeboard, or the like, without the use of external tools. A spacer plate which enables the mounting of the binding in a position above the board is combined with a mechanism which can change its thickness on demand, thereby locking or unlocking the binding from a freely rotatable position.
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BACKGROUND
[0001] 1. Field
[0002] The present invention relates to cold-liquid drinking vessels and more particularly to beer steins.
[0003] 2. Related Art
[0004] In U.S. Pat. No. 4,424,990, White et al disclose thermo-chromic compositions which change color with temperature changes. These compositions are commercially available and are used in thermometers and novelty items, and simply reflect the ambient temperature of the liquids within the vessels. They do nothing to affect the temperatures or to keep the beverage cold.
[0005] In U.S. Pat. No. 5,156,283, Sampson teaches that a beer stein should be of suitable material so as to not be conductive of heat and proposes a wooden stein. Further, Sampson teaches that decorative emblems can be embedded in the wood to increase the attractiveness of the drinking container, however this proposal has a limiting effect as to what materials may be used in the construction of the beer stein.
[0006] Fremin, in U.S. Pat. No. 4,919,983 teaches that by using plastic thermo-chromic materials in forming a baby bottle, it is possible to indicate when the contents of the bottle are too hot to drink, but again, this does nothing to alter the temperature of the bottle contents.
SUMMARY
[0007] Embodiments of the present invention relate to a stackable stein that includes a body. The body includes an outer cylindrical wall wider at a first base end than at an opposite first upper end; an inner cylindrical wall having a second base end and an opposite second upper end; and a frustoconical annular region formed between an outer surface of the inner cylindrical wall and an inner surface of the outer cylindrical wall. The inner and outer cylindrical walls are configured such that a) the second base end comprises a closed base region, b) the first upper end and the second upper end form a common upper region, and the first base end and the second base end extend to substantially a same orthogonal distance from the common upper region. The stackable stein also includes a detachable bottom configured to releasably attach to the first base end. The stackable stein may also include a detachable handle configured to releasably attach to at least an outer surface of the outer cylindrical wall.
[0008] Another embodiment of the present invention relates to a plurality of stackable steins. Each of the steins include a body formed from a) an outer cylindrical wall wider at a first base end than at an opposite first upper end; b) an inner cylindrical wall having a second base end and an opposite second upper end; wherein the first upper end and the second upper end form a common upper region and the first base end and the second base end extend to substantially a same orthogonal distance from the common upper region; and c) a frustoconical annular region formed between an outer surface of the inner cylindrical wall and an inner surface of the outer cylindrical wall. Moreover, the plurality steins are nested together in an arrangement from a bottom stein to a top stein whereby the common upper region of a lower stein in the arrangement is fitted within the frustoconical annular region of an adjacent, next-higher stein in the arrangement.
[0009] Yet another embodiment of the present invention relates to a kit of disposable steins that includes a plurality of stackable steins; a plurality of detachable bottoms, each bottom configured to releasably attach to the first base end of one of the plurality of stackable steins; and a plurality of detachable handles; each handle configured to releasably attach to at least an outer surface of the outer cylindrical wall of one of the plurality of stackable steins. Each of the steins include a body formed from a) an outer cylindrical wall wider at a first base end than at an opposite first upper end; b) an inner cylindrical wall having a second base end and an opposite second upper end; wherein the first upper end and the second upper end form a common upper region and the first base end and the second base end extend to substantially a same orthogonal distance from the common upper region; and c) a frustoconical annular region formed between an outer surface of the inner cylindrical wall and an inner surface of the outer cylindrical wall. Moreover, the plurality steins are nested together in an arrangement from a bottom stein to a top stein whereby the common upper region of a lower stein in the arrangement is fitted within the frustoconical annular region of an adjacent, next-higher stein in the arrangement. The kit may also include a freezing tray with a structure for holding liquid coolant to be frozen, wherein the structure is complementary in shape to the frustoconical annular region whereby coolant frozen in the structure fits within the frustoconical annular region.
[0010] It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only various embodiments of the invention by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Various aspects of a system and method for anesthesia monitoring are illustrated by way of example, and not by way of limitation, in the accompanying drawings, wherein:
[0012] FIG. 1 is a sectional view of the beer stein showing the ear handle inserted in place and with no bottom provided.
[0013] FIG. 2 is an exploded sectional view of the beer stein including a snap-in bottom and the adhesive attachment for the exploded ear handle showing the receptive holes for the attaching the ear handle.
[0014] FIG. 3 is a top view pictorial of the items described in FIG. 2 .
[0015] FIG. 4 is a bottom view pictorial of the items described in FIG. 1 .
[0016] FIG. 5 is an exterior view of the items in FIG. 1 along with any arbitrary insignia.
[0017] FIG. 6 is an exploded pictorial of the beer stein with the snap-in bottom attachable ear handle and the attachment adhesive.
[0018] FIG. 7 is a pictorial of an alternate design for the ear handle.
[0019] FIG. 8 is a pictorial the screw-in or snap-in bottom showing a grip handle.
[0020] FIG. 9 is sectional view of the beer stein with the snap-in bottom showing the reflective-foil covered Styrofoam liner.
[0021] FIG. 10 is a sectional view of the drinking vessel without the ear handle and showing the stacking capability of the invention.
[0022] FIG. 11 is an exterior view of the drinking vessel without a handle showing a roughened gripping surface.
[0023] FIG. 12 is a sectional view of the drinking vessel with the screw-on bottom in place.
[0024] FIG. 13 is a sectional view of the drinking vessel with the screw-on bottom exploded.
[0025] FIG. 14 is an enlarged sectional view of the drinking vessel with the screw-on bottom in place.
[0026] FIG. 15 is an enlarged sectional view of the drinking vessel.
[0027] FIG. 16 is an enlarged sectional view of the screw-on bottom.
[0028] FIG. 17 is an enlarged sectional detail of the drinking vessel.
[0029] FIG. 18 is an enlarged sectional detail of the screw-on bottom.
[0030] FIG. 19 is a top view pictorial of the stein and the screw-on bottom.
[0031] FIG. 20 is a bottom view pictorial of the beer stein and the screw-on bottom.
[0032] FIG. 21 is a sectional view showing the glass, the funnel, and the screw-on bottom assembled.
[0033] FIG. 22 is a sectional view showing the funnel and the screw-on bottom disassembled.
[0034] FIG. 23 is a sectional view of the glass.
[0035] FIG. 24 is a pictorial view of the assembled stein viewed from above right.
[0036] FIG. 25 is a pictorial view of the assembled stein viewed from below left.
[0037] FIG. 26 is an exploded pictorial viewed from above left.
[0038] FIG. 27 is a sectional view showing a shallow bottom interior section with a full deep-bottom lid and cinch top.
[0039] FIG. 28 is a diagram showing how the stein shape is derived from a truncated cone.
[0040] FIG. 29 is a pictorial view showing how one truncated cone nestles into another.
[0041] FIG. 30 is a pictorial showing how the attachable handle does not penetrate the outer cone.
[0042] FIG. 31 is a pictorial view showing the bottom of the ice tray.
[0043] FIG. 32 is a pictorial view showing the top view of the ice tray.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the invention.
[0045] The beer stein, with the base larger than the top lip, symbolically represents the art of brewing and drinking beer. Until now, there has been no way of economically providing the natural image of the festival at a beer festival as most of the beer at such events is served out of plain plastic or paper cups. By utilizing this present invention, fraternities at beer blasts can provide a drinking mug with the fraternity insignia on the side with the possibility of also providing a souvenir of the occasion. The additional bonus comes from being able to keep the beer chilled without diluting it with the water from melting ice. The present invention need not be restricted to beer containers as it is equally effective at keeping other beverages cold without the container having the requisite handle of the beer stein. For example, colas and other soft drinks can be kept cold without the unwanted effect of having them diluted by melting ice. Another benefit arising from the design of the present invention is, by using the detached handle, the ability of wholesalers to stack the drinking containers for ease of shipping great quantities.
[0046] In the prior art, many inventors have experimented with the materials used in creating the beer mug and with decorative designs affixed to or imbedded in the containers, however no one has created a design that is stackable, larger at the bottom than at the top, and is able to maintain the coldness of the liquid. Most of these inventions demonstrate no utilitarian purposes beyond those exhibited by the original, conventional designs of time-honored beer steins as most are add-on advertising gimmicks.
[0047] Currently, there does exist a double-wall, plastic freezer mug that contains a gelatinous liquid that is permanently sealed within the walls. This freezer mug is to be placed in the freezer for an extended time to achieve a frozen state for the contained liquid. The significant differences between this item and the present invention is that (1) it is not stackable, (2) it is not designed to ever be disposable, and (3) its design is not applicable to low-cost materials making it impractical for use at public ventures such as beer festivals.
[0048] Beer steins and other vessels for consuming liquids have traditionally been made of a variety of materials including but not limited to glass, ceramic, plastic, Styrofoam, and metal. Ideally, a drinking container is one that should be not conductive of heat, will not affect the taste or consistency of the beverage, and will not drip condensation from the air which has accumulated on the outside of the container onto furniture or other surfaces. All of the above materials, with the exception of Styrofoam will, in most surrounding climates that are warmer than the liquid contents of the container, collect condensate on the exterior walls of the container which will then run down onto the surface upon which the container is sitting. A vessel that is designed to collect the condensate within a hollow chamber and which has that said hollow chamber insulated from the warmer outer temperatures both on the sides and on the bottom by a Styrofoam lining will effectively combat that problem.
[0049] With most liquids such as soda, tea, milk, or lemonade, it is desirable that they be consumed at a cold temperature, and this is accomplished by drinking rapidly or by floating ice in the liquid within the container. When ice made from solid water is floated in the said liquid, it will melt in the liquid, turning the ice back into water and thereby reducing the potency of the liquid that is being consumed and making it less concentrated than when originally poured. If ice is not placed in the liquid for cooling purposes, the temperature of said liquid immediately begins to become heated by the ambient external temperature making it unpleasant to drink within a short period of time. By keeping the coolant, which effectively might be regular ice or dry ice, separate from the contained liquid, a desirable cold temperature can be maintained while at the same time retaining the original potency of the liquid.
[0050] Because beer steins have traditionally been made of various materials—metal, glass, and ceramic being chief among the materials being used, and with modern-day disposable cups being made of paper, wax-covered paper, plastic, and Styrofoam, the stackable stay-cold beer stein is designed in such a manner as to permit interchangeable parts of varying materials. For instance, the outer cone shell may be made of plastic lined with Styrofoam and then with reflective foil while the inner cup section can be made of plastic or ceramic or glass depending upon which material is most pleasing to the lips of the user. Reusable steins can have a screw-on, insulated bottom while disposable cups may have a snap on, plastic bottom for securing the dry or water ice coolant within the hollow, cooling chamber.
[0051] Because the stackable, stay-cold beer stein will be desirable for use at festive, memorable occasions, logos of fraternities, businesses, of festivals may be either printed on the outsides of the mugs, or they may be affixed to the outsides by peel-off labels such as those used on the year ID tags of automobile license renewals or from sheets printed in a manner similar to postage stamps. Likewise, the detached handles may be attached to the mugs after shipment by using peel-off tape that is already affixed to the ears prior to shipping.
[0052] The present invention, a stackable, stay-cold drinking vessel, is shown in FIG. 24 , FIG. 25 , and FIG. 26 . The detailed description set forth below in connection with the drawings is intended as a description of various embodiments of the invention and is not intended to represent the only embodiment in which the invention may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the invention, however it will be readily apparent to those skilled in the art that there may be overlapping specifics and that the invention may be practiced without these specific details.
[0053] Embodiments of the present invention relate to a drinking vessel that, with the introduction of water ice or dry-ice into a specially designed chilling compartment has the ability to maintain a cold temperature to the liquid in the consumption part of the vessel without diluting is potency. This design feature that is built into the vessel also has the ability to allow the vessels to be stacked thereby allowing for greater ease in shipping. The vessel may be made of a variety of materials—i.e. paper, wax coated paper, plastic, Styrofoam, ceramic, metal, glass, or any combination thereof. The invention can be made to be disposable, or it can be made to be kept for re-use or to save as a souvenir item.
[0054] The basic concept for the shape of the stay-cold beer stein could be said to be derived from a slender cone that has been truncated into three equal heights ( FIG. 28 . and FIG. 29 ). The circumference of the top 41 of the base section 42 is congruent with the circumference of the base 41 of the middle section 40 . When the middle section 40 of the cone is inverted FIG. 30 , inserted into the base section, and sealed at the top, it forms the basic design for the stay-cold beer stein. There is no purpose for the top section of the cone in this design.
[0055] Also, in its most basic form, this present invention would be made of a disposable material such as thin plastic, paper, or wax covered paper, and it would consist of four separate pieces—the stackable structure 1 , the attachable handle 3 , the adhesive tape 13 for attaching the handle to the stackable structure, and the snap-in bottom 19 for securing the ice within the chilling chamber 4 , shown in FIG. 1 , FIG. 2 , FIG. 25 and FIG. 26 . If the inner vertical annular supports 21 and the outer vertical annular supports 20 on the snap-in bottom 19 are tall enough and fit under a drip cap (see FIG. 2 and FIG. 8 ) the water from melting ice will not seep out onto the table upon which the stein might be resting. Rather, it will be collected in the closing ring 23 (of FIG. 8 ) or 37 & 38 (of FIG. 27 ) of the snap-in bottom.
[0056] One reason for having an attachable handle for the beer stein is to maintain the stackable aspect of the design for ease of shipping as shown in FIG. 10 . For his reason, upper openings 10 and lower openings 14 may be designed into the basic structure allowing for the handles 3 to be attached after shipment. To achieve this end, adhesive tape 13 with a pull off tab similar to double sticky tape is attached to the support surface 15 on the handle. When the upper support nodule 11 and the lower support nodule 5 are inserted into the said upper and lower openings, the said tape presses against a section on the outer funnel 12 and this causes the handle to become permanently affixed to the funnel of the stackable beer stein. See FIG. 1 , FIG. 2 , and FIG. 3 . An alternate design for the upper support nodule FIG. 7 extends farther 22 into the chilling chamber and provides a hook shape on the top 18 for the purpose of locking the upper support into the chilling chamber and giving additional support without the danger of the handle being pulled out by the force of lifting. A third handle concept would be for the slot 44 FIG. 30 in the outer shell to be simply an indention in the exterior and not penetrate completely through thereby leaving the chilling chamber water tight. The support nodule 45 would still be affixed inside the slot with double sticky sealing tape 46 . If the design concept is to be used as a simple glass with a chilling chamber for drinking such beverages as colas, soda pops, tea, or milk, there would be no requirement for the support nodule holes as a handle would not be required. However, since the shape would taper upward, a gripping surface 28 , FIG. 11 , might be designed into the shape to aid in lifting the glass. Aside from the novelty of drinking out of a vessel where the bottom has the appearance of a greater diameter than the top rim, with either design, the shape would still be more stable when resting on a table because there would be more weight at the bottom than at the top due to the nature of the design. The design lends itself to having the lower rim of the funnel shape 16 , as shown in FIG. 2 & FIG. 4 , rather than the bottom lid resting on the table for the sake of stability. For the ease of inserting and removing the bottom lid from the main structure, a hand grip 26 , as shown in FIG. 8 & FIG. 19 , is designed into the lid, and the bottom, interior of the one-piece casting 7 should be sufficiently shallow enough for this to happen.
[0057] In order for the chilling chamber to function most effectively, a Styrofoam funnel-shaped insulating liner with a reflective inner lining 24 , as shown in FIG. 9 & FIG. 22 , may be designed into the outer funnel portion of the basic structure. Also for insulating purposes, an annular Styrofoam ring 25 may be included with the snap-in or screw-in bottoms. In either the inexpensive version of all plastic or the more permanent version of the invention, if the bottom of the interior section of the one piece casting 7 does not extend to the bottom circumference ring 16 of the exterior section, then there would be no need for the donut hole in the bottom lid, and it would be cast as one piece 37 . In this configuration, the thin plastic outer vertical annular supports 20 on the snap-in would extend farther into the hollow of the outer ring. It would also curve outward in a semi-circular shape before curving inward 38 , to fit snugly under an annular drip cap 39 to prevent the melted water from seeping out onto the support upon which the stein is sitting, and the bottom lid would become a holding receptacle for the melted ice. Since the upper circumference is curving inward, this would provide for easier installation of the lid as well as creating a tighter, more leak-proof seal.
[0058] In its more permanent and expensive form, this present invention would be made of more durable materials such as metal, heavy plastic, ceramic, glass, Styrofoam, or combinations of the said materials, and it would be suitable for being washed. It could be made of as many as five different parts which could possibly be assembled by screwing the parts together as shown in FIGS. 19 , 20 , 21 , 22 , & 23 . The purpose for being able to disassemble all the parts would be for most effective dishwasher cleaning. The outer funnel-shaped shell 8 would be lined with Styrofoam 24 , as shown in FIG. 22 , and would be threaded at the top rim 35 .
[0059] Likewise, the inner glass would be threaded at the top rim 36 , as shown in FIG. 23 , in order to screw into the outer funnel-shell. The inner glass of the tankard would also be threaded at the bottom rim 32 , as shown in FIG. 17 & FIG. 23 , to receive the inner threaded portion 33 of the bottom lid. The outer funnel-shaped shell would also be threaded on the inside of the bottom rim 34 , in order to receive the outer threaded portion of the bottom lid 35 (see FIG. 22 .)
[0060] When the bottom lid is screwed in tightly into the assembled beer stein or drinking vessel, a water tight seal is formed between the abutting surfaces 28 , 19 , 30 , 31 as shown in FIGS. 17 , 18 , & 19 .
[0061] Functionally, the most effective way to introduce ice into the chilling chamber of the stay-cold beer stein would be to fill the chilling chamber with water to a predetermined fill-line and place it inverted into the freezer. When the stein is then removed to be used, the water-tight bottom could be affixed and the vessel would be ready to be filled with any preferred beverage. Secondly, the most practical, time-efficient, and cost effective way of introducing ice into the chilling chamber is simply to scoop crushed ice into the vessel by using the handle as a scoop and then inserting the removable water-tight bottom. Another way to introduce the ice would be to have the ice preformed into the requisite funnel shape by having plastic or polyurethane ice trays that are designed to accomplish this end as shown in FIG. 31 and FIG. 32 . By this method, trays 47 are formed having an outer truncated cone 48 with a sealed bottom 49 and an inner truncated cone 43 with sealed top 51 that together form a freezing chamber 50 . Ultimately, for use in commercial establishments, ice machines could be manufactured to produce the funnel-shaped ice that would be necessary to accommodate the business at a commercial establishment.
[0062] In order to make any drinking glass or beer stein event specific to the occasion or sponsor specific, the business, club, or organization logo can be printed on the exterior of the mug at the manufacturing plant, or it may be affixed later at the usage destination by using paste-on decals 17 as shown in FIG. 5 .
[0063] Referring back to FIG. 1 and FIG. 2 , aspects of the present invention relate to a stackable stein that includes a body. The body includes an outer cylindrical wall 106 wider at a first base end 105 than at an opposite first upper end 107 such that the outer cylindrical wall 106 slants outwardly at its bottom. The stein body also includes an inner cylindrical wall 104 having a second base end 111 and an opposite second upper end 109 . The body includes a frustoconical annular region, or cavity, 114 formed between an outer surface 120 of the inner cylindrical wall 104 and an inner surface 121 of the outer cylindrical wall 106 . The inner and outer cylindrical walls 104 , 106 are configured such that a) the second base end 111 comprises a closed base region 108 , b) the first upper end 107 and the second upper end 109 form a common upper region 102 , and the first base end 105 and the second base end 111 extend to substantially a same orthogonal distance d 1 (see FIG. 1 ) from the common upper region 102 . The stackable stein also includes a detachable bottom 110 configured to releasably attach to the first base end 105 . The stackable stein may also include a detachable handle 112 configured to releasably attach to at least an outer surface of the outer cylindrical wall.
[0064] As a result of this construction, the stein body is stackable or nestable because at any particular orthogonal distance d 2 from a top of the common upper region 102 towards the first base end 105 an outer diameter of the outer cylindrical wall 106 is less than or substantially equal to an outer diameter of the frustoconical annular region 114 at approximately that same particular orthogonal distance d 3 from a bottom of the common upper region 102 . The stein of FIG. 1 can thereby be stacked together as shown in FIG. 10 . The distance d 3 , which is “approximately d 2 ” from the bottom of the common upper region 102 , is “approximate” because the steins (as shown in FIG. 10 ) do not nest perfectly. There is a gap 130 between the bottom of the common upper region 102 A of an upper-located stein and the top of the upper common region 102 B of a lower-located stein. If this gap 130 did not exist, then the relationship about the outer diameter of the outer cylindrical wall being less than the outer diameter of the frustoconical annular region would be true for d 2 =d 3 . However, the gap 130 can be as much as a few millimeters and, thus, the relationship about those outer diameters holds true for d 2 ≈d 3 where d 3 is larger than d 2 an amount the same as the size of the gap 130 .
[0065] Also, in most instances, the outer diameter of the outer cylindrical wall at that particular orthogonal distance is approximately equal to the outer diameter of the frustoconical annular region at approximately that same particular orthogonal distance. This relationship expresses the construction that, when nested, the gap 132 (see FIG. 10 ) between two adjacent stein's outer cylindrical walls is negligible in size and can be a millimeter or less.
[0066] When a plurality of steins are stacked together, the plurality of steins are nested together in an arrangement from a bottom stein 134 to a top stein 136 whereby the common upper region 102 B of a lower stein 134 in the arrangement is fitted within the frustoconical annular region of an adjacent, next-higher stein 136 in the arrangement. The positional terms such as “bottom”, “upper”, “lower”, etc. as used herein are used for convenience with respect to a particular frame of reference illustrated in the figures. However, one of ordinary skill will recognize that there terms can be changed without departing from the scope of the present invention. For example, the nested arrangement of FIG. 10 can also occur if the frame of reference were flipped 180 degrees so that a “lower” item” would then become a “higher” item.
[0067] The previous description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the full scope consistent with each claim's language, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
[0068] Below is a legend table for the elements depicted in FIGS. 1-32 . Functional names and labels have been given to each element but are not intended to limit these elements to only these functions but rather to aid the reader in understanding embodiments of the present invention.
1 . Stackable structure of the beer stein 2 . Chamber for holding the liquid 3 . Stein handle or ear 4 . Chilling chamber for holding the dry ice or water ice 5 . Lower support nodule on ear to aid attachment to stackable structure 6 . Thickened material for one-piece casting of the stackable structure 7 . Bottom of interior section of one-piece casting 8 . Outer funnel portion of beer stein 9 . Inner wall of beer stein 10 . Upper opening to receive top support nodule on detached handle 11 . Upper support nodule on handle to support and aid attachment to stackable structure 12 . Portion on outer funnel portion that receives the attachment tape 13 . Attachment tape 14 . Lower opening to receive bottom support nodule on detached handle 15 . Surface on detached handle that receives the attachment tape 16 . Bottom circumference rim of the one-piece casting 17 . Paste-on insignia 18 . Alternate design for upper support nodule on handle 19 . Snap-in or screw-in bottom 20 . Outer vertical annular supports on snap-in bottom 21 . Inner vertical annular supports on snap-in bottom 22 . Alternate design of upper support nodule (item 11 ) 23 . Closing ring for snap-in bottom 24 . Styrofoam insulating cone on “the inner surface of the outer funnel (item 8 ) 25 . Annular Styrofoam insulation on closing ring of the snap-in bottom 26 . Hand grip on snap-in or screw-in bottom 27 . Rounded upper drinking rim 28 . Annular compression seal on tankard 29 . Inner annular compression seal on screw-in bottom 30 . Outer annular compression seal on screw-in bottom 31 . Annular compression seal on funnel 32 . Inner threads on tankard connecting to screw-in bottom 33 . Inner threads on screw-in bottom that connect to tankard 34 . Outer threads on screw-in bottom that connect to matching threads on funnel 35 . Top threads on funnel shell 36 . Top threads on glass or tankard 37 . One-piece bottom lid 38 . Leak preventing cinch top of bottom lid 39 . Leak preventing cinch within the outer cone 40 . Second lowest truncated cone 41 . Shared diameter on lowest and second lowest truncated cones 42 . Lowest truncated cone 43 . Inverted second lowest cone 44 . Slot that does not penetrate the outer cone 45 . Support on handle 46 . Adhesive to fit in slot 47 . Ice tray 48 . Outer cone of ice tray 49 . Bottom of truncated outer cone on ice tray 50 . Hollow portion of ice tray to receive water for freezing 51 . Top of truncated inner cone on ice tray
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A drinking vessel that has the capability to be stackable and which, by using regular water ice or dry ice, has the ability to maintain a cold temperature for the beverages while not diluting the potency of the liquid or diminishing the quality of the taste. The stackable aspect of the design allows the containers to be nestled within each other allowing for greater quantities of the vessels to be shipped at a single time. A sealable, removable bottom allows for the ice to be secured with the hollow chilling chamber. A handle, which may be formed into the vessel at the time of casting or may be attached after shipping, along with the base that is larger in diameter than the top because to the stacking feature, create the appearance of a traditional beer stein.
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FIELD OF THE INVENTION
The present invention is a CIP of application Ser. No. 13/584,833, filed Aug. 14, 2012, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Description of the Prior Art
In a conventional alignment platform such as the ultrahigh load alignment device is disclosed in TW200912688. In TW200912688, the device uses three sets of driving devices to drive three sets of moving devices moving linearly so as to drive the moving plateform moving or rotating. When the rotation of the moving plateform is required, the three sets of driving devices must cooperate synchronously, which is uneasy to make the moving plateform move along a circular path precisely. As a result, as a controller or a computer drives the driving devices operating, the controller or the computer have to processing a great quantity of calculation, thus increasing the processing and response time and affecting the work efficiency.
To improve the defects like that in TW200912688, the inventor had invented an alignment stage applied for a TW patent application with application No. 099118614 which had been granted as TWI390144. The alignment stage includes three power units and three moving units. Two of the power units can drive a third moving unit moving in either of two different directions. The other power units can drive the third moving unit rotating individually. Each power unit is electrically connected to a controller for respectively driving and controlling each power unit. When only the rotation of the third moving platform is required, only one of the power units needs to be driven, thus simplifying the operation of the alignment platform and improving the work efficiency.
However, the inventor has been seeking a better alignment platform, and a xyθ precision alignment platform is provided in this application, to obviate or at least mitigate the above mentioned disadvantages.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a xyθ precision alignment platform which can accurately and precisely control and adjust the rotation angle.
Another object of the present invention is to provide a xyθ precision alignment platform which can easily drive workpiece moving and rotating and simplify the operation.
Another object of the present invention is to provide a xyθ precision alignment platform which is thin.
To achieve the above and other objects, a xyθ precision alignment platform includes a base, at least one Y-axis guideway unit, a first moving platform, a first power unit, at least one X-axis guideway unit, a second moving platform, a second power unit, a third moving platform, a rotating unit and a third power unit. The at least one Y-axis guideway unit is mounted to the base. The first moving platform is movably coupled with each Y-axis guideway unit, the first moving platform and the base being parallel. The first power unit includes a first motor and a first rod member driven by the first motor, and the first motor is mounted to the base, wherein the first motor drives the first rod member moving to move the first moving platform along each Y-axis guideway unit move. The at least one X-axis guideway unit is co-movable with the first moving platform, and the X-axis guideway unit and the Y-axis guideway unit are nonparallel. The second moving platform is movably coupled with each X-axis guideway unit, and the second moving platform and the base are parallel. The second power unit includes a second motor and a second rod member driven by the second motor, and the second motor is mounted to one of the first moving platform, the first rod member and each X-axis guideway unit, wherein the second motor drives the second rod member to move the second moving platform along each X-axis guideway unit. The third moving platform is rotatably disposed correspondingly above the second moving platform, the third moving platform and the base parallel. The rotating unit is disposed between the second moving platform and the third moving platform and has a circumferential arcuate teeth arrangement. The third power unit is disposed by a lateral side of the second moving platform and includes a third motor and a worm driven by the third motor and engaged with the arcuate teeth arrangement, wherein the third motor drives the worm rotating to drive the arcuate teeth arrangement to move the third moving platform to rotate relative to the base.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment(s) in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective drawing according to a preferred embodiment of the present invention;
FIG. 2 is a partial breakdown drawing according to a preferred embodiment of the present invention;
FIG. 3 is a perspective breakdown drawing according to a preferred embodiment of the present invention;
FIG. 4 is a side view according to a preferred embodiment of the present invention;
FIG. 5 is a perspective breakdown drawing showing an alignment platform having plural sets of first and second power units according to a preferred embodiment of the present invention;
FIGS. 6 to 8 are drawings illustrating a xyθ precision alignment platform in use according to a preferred embodiment of the present invention;
FIG. 9 is a partial breakdown drawing according to an alternative embodiment of the present invention;
FIG. 10 is a breakdown drawing according to another embodiment of the present invention; and
FIG. 11 is a breakdown drawing according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 4 show a xyθ precision alignment platform according to a preferred embodiment of the present invention. The xyθ precision alignment platform includes a base 1 , four Y-axis guideway units 2 , a first moving platform 3 , a first power unit 4 , four X-axis guideway units 5 , a second moving platform 6 , a second power unit 7 , four θ-angle guideway units 8 , a third moving platform 9 , a rotating unit 10 and a third power unit 11 .
The base 1 is a plate body which can be adapted to dispose on a plane. The base 1 defines a longitudinal direction and a width direction, and may be formed with one or more recesses 12 .
The Y-axis guideway units 2 are mounted to the base 1 , and each Y-axis guideway unit 2 is engaged in each recess 12 . The Y-axis guideway units 2 are parallel. Alternatively, only one Y-axis guideway unit 2 is mounted to the base 1 .
The first moving platform 3 is movably coupled with the Y-axis guideway units 2 so that the first moving platform 3 is movable along the Y-axis guideway units 2 . The first moving platform 3 and the base 1 are parallel. The first moving platform 3 may include a plate body 31 and at least one sliding block 32 . Each sliding block 32 of each first moving platform 3 is mounted to the plate body 31 of the first moving platform 3 so that each sliding block 32 of each first moving platform 3 and the plate body 31 of the first moving platform 3 are in a cooperative relationship. The sliding blocks 32 of the first moving platform 3 are movably coupled with the Y-axis guideway unit 2 , respectively. The plate body 31 of the first moving platform 3 is formed with at least one recess 311 .
The first power unit 4 includes a first motor 41 and a first rod member 42 driven by the first motor 41 . The first motor 41 is mounted to the base 1 . The first motor 41 can drive the first rod member 42 moving, and the moving first rod member 42 can move the first moving platform 3 along the Y-axis guideway units 2 .
The X-axis guideway units 5 are mounted to the first moving platform 3 , or each X-axis guideway unit 5 can be engaged in each recess 311 so that each X-axis guideway unit 5 and first moving platform 3 are co-movable. Each X-axis guideway unit 5 and each Y-axis guideway unit 2 are nonparallel. Alternatively, only one X-axis guideway unit 5 is mounted to the first moving platform 3 .
The second moving platform 6 is movably coupled with the X-axis guideway units 5 so that the second moving platform 6 is movable along the X-axis guideway units 5 . The second moving platform 6 is preferably parallel to the base 1 . The second moving platform 6 may include a plate body 61 and at least one sliding block 62 . Each sliding block 62 of each second moving platform 6 is mounted to the plate body 61 of the second moving platform so that each sliding block 62 of the second moving platform 6 and the plate body 61 of the second moving platform are in a cooperative relationship. The sliding blocks 62 of the second moving platform 6 are movably coupled with the X-axis guideway units 5 , respectively. The plate body 61 of the second moving platform 6 may further be formed with at least one groove 611 .
The second power unit 7 includes a second motor 71 and a second rod member 72 driven by the second motor 71 . The second motor 71 is mounted to the first moving platform 3 . Specifically, the second motor 71 may be mounted to the plate body 31 of the first moving platform 3 . In other embodiments, the second motor 71 may be mounted to the first rod member 42 or one of the X-axis guideway units 5 so that the first moving platform 3 can drive the second motor 71 moving synchronously. The second motor 71 can drive the second rod member 72 moving, and the moving second rod member 72 can move the second moving platform 6 along the X-axis guideway units 5 . The second power unit 7 and the first power unit 4 , respectively, drive the second moving platform 6 and the first moving platform 3 moving in different directions. The second rod member 72 and the first rod member 42 extend in different directions. As shown in FIG. 5 , the first power unit 4 may include plural sets of first motor 41 and first rod member 42 . The second power unit 7 may include plural sets of second motor 71 and second rod member 72 . The first motors 41 and second motors 71 are disposed respectively by lateral sides of the base 1 and the first moving platform 3 .
The θ-angle guideway units 8 are mounted to the second moving platform 6 , or each θ-angle guideway unit 8 may be engaged in each groove 611 so that each θ-angle guideway unit 8 and the second moving platform 6 are in a cooperative relationship. The θ-angle guideway unit 8 is formed as an arced guiding track. Optionally, only one θ-angle guideway unit 8 is mounted to the second moving platform 6 , or the θ-angle guideway unit may extend to form a circular member.
The third moving platform 9 is disposed correspondingly above the second moving platform 6 and coupled with the θ-angle guideway units 8 in such a manner that the third moving platform 9 is rotatable along the θ-angle guideway units 8 . The third moving platform 9 and the base 1 are parallel. In this embodiment, the third moving platform 9 includes a plate body 91 and at least one sliding block 92 . Each sliding block 92 of the third moving platform 9 is mounted to the plate body 91 of the third moving platform 9 . The sliding blocks 92 of the third moving platform 9 are movably coupled with the θ-angle guideway units 8 , respectively.
The rotating unit 10 is mounted between the second moving platform 6 and the third moving platform 9 and has a circumferential arcuate teeth arrangement 101 . Specifically, the arcuate teeth arrangement 101 is formed as a circular teeth arrangement, and the arcuate teeth arrangement 101 is preferably disposed within the outermost edge of the third moving platform 9 so that the lateral dimension of the alignment platform is reduced. Corresponding to the base 1 , a top surface of the rotating unit 10 is preferably not higher than a top surface of the third moving platform 9 , and more preferably, lower than a bottom surface of the third moving platform 9 so that the base 1 and the third moving platform 9 are close to each other and the alignment platform is therefore thin. In addition, the rotating unit 10 may be disposed between the second moving platform 6 and the third moving platform 9 so that the rotating unit 10 can be well protected and is not easy to be interfered, accidentally contacted or damaged.
The third power unit 11 is disposed by a lateral side of the second moving platform 6 and includes a third motor 111 and a worm 112 driven by the third motor 111 and engaged with the arcuate teeth arrangement 101 . The second moving platform 6 can drive the third motor 111 , and the moving third motor 111 can drive the worm 112 rotating to drive the arcuate teeth arrangement 101 to move the third moving platform 9 along each θ-angle guideway unit 8 to rotate relative to the base 1 .
Please refer further to FIG. 6 , as the first motor 41 rotates, the first moving platform 3 moves along the Y-axis guideway unit 2 and drives the X-axis guideway units 5 moving so as to move the second moving platform 6 and third moving platform 9 along Y-axis guideway unit 2 . Please refer further to FIG. 7 , as the second motor 71 rotates, the second moving platform 6 moves along the X-axis guideway unit 5 and drives the θ-angle guideway units 8 moving so as to move the third moving platform 9 along the X-axis guideway unit 5 . Please refer further to FIG. 8 , as the third motor 111 rotates, the worm 112 is driven to move the arcuate teeth arrangement 101 so that the third moving platform 9 can be driven to rotate along the θ-angle guideway units 8 . Whereby, the third moving platform 9 is able to move along the Y-axis guideway unit 2 , the X-axis guideway unit 5 or the θ-angle guideway units 8 . When the third moving platform 9 is required to rotate, the first motor 41 and second motor 71 need not to be driven, thus resulting a simple operation and easing the work load of the controller and reducing response time of the controller.
It is noted that, the alignment platform may be alternatively configured in a structure such as that shown in FIG. 9 . As shown in FIG. 9 , a rotating unit may include a bearing 102 , wherein an arcuate teeth arrangement 101 ′ of the rotating unit is formed as a circular teeth arrangement and around the bearing 102 . The circular teeth arrangement and a third moving platform 9 ′ are cooperative with each other, and the circular teeth arrangement is rotatable around the bearing 102 . In aforementioned embodiment, each plate body is a quadrilateral hollow plate body; however, each plate body may be a quadrilateral solid plate body (for example, the third moving platform 9 ′ arranged as the top plate). Optionally, as shown in FIG. 10 , an arcuate teeth arrangement 101 ″ is noncircular and a part of a circular teeth arrangement, wherein the extent of the arcuate teeth arrangement 101 ″ may be designed according various requirements or may be constructed by plural arcuate tooth parts separately arranged. Alternatively, as shown in FIG. 10 , a bearing 102 ′ is disposed between the second moving platform 6 and the third moving platform 9 .
It is noted that, an optical ruler may be equipped to the alignment platform, which can improve the control of rotation angle and the precision of measurement and digitalize the rotation angle with small scale for reference. As a result, the user can accurately and precisely control and adjust the rotation angle accordingly, and the alignment platform can be applied to tasks requiring high precision such as to assemble miniature parts or to machine processing or etching.
In the present invention, through the cooperation of the worm and the arcuate teeth arrangement, every circle of rotation of the worm can cause the arcuate teeth arrange rotatively travel with only for a tooth-wide distance, thus avoiding the unenablement of fine adjustment of the third moving platform due to the fast rotation speed of the third motor, and achieving accurate and precise control and adjustment of the rotation angle of the alignment platform.
Furthermore, in the present invention, since each motor is disposed by the lateral side of the first moving platform or the second moving platform, each motor and each moving platform are stacked so that the alignment platform is thin.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
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A xyθ precision alignment platform is provided. The alignment platform includes three power units and three moving platform. Two of the power units can drive a third moving platform moving in X or Y direction. The other power unit has a worm which can drive an arcuate teeth arrangement disposed between the second moving platform and the third moving platform to drive the third moving platform rotating. Whereby, since the worm is arranged to drive the arcuate teeth arrangement laterally, the alignment platform is thin and the rotative movement of the third moving platform can be precisely controlled. Additionally, each power unit may be electrically connected to a controller for respectively driving and controlling each power unit. When only the rotation of the third moving platform is required, only one of the power units needs to be driven, thus simplifying the operation of the alignment platform and improving the work efficiency.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 360,660 and now abandoned, filed May 14, 1973.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of clinical diagnostic reagents and more particularly to reagents containing a hormone substance tagged with radioisotopic iodine and useful for in vitro (thyroid) function determinations.
2. Description of the Prior Art
It is known to measure the unsaturated binding capacity of blood serum by admixing a sample of serum with a buffered solution containing a known amount of thyroid hormone labeled with a radioactive isotope of iodine and an ion-exchange resin or other solid sorbent substance such as charcoal, talc, magnesium silicate, and the like capable of binding the excess labeled hormone so that it can be separated and removed from the serum sample. The amount of labeled hormone taken up by the serum protein, primarily thyroxine-binding globulin, can then be determined directly or indirectly using a scintillation counter. Such tests are commonly known in the art as T-3 tests.
In the most commonly used forms of this test, the solid sorbent material is added after the serum sample and the labeled hormone solution are combined in which case the function of the sorbent is limited to binding the excess, i.e. free or unbound, hormone so that it can be separated from the liquid serum sample containing the protein-bound hormone.
In another form of this test (U.S. Pat. No. 3,507,618), the labeled hormone is initially bound to an ion-exchange resin, and in this form the test depends upon desorption of the hormone from the ion-exchange resin carrier. This method is satisfactory provided that the charged resin is freshly prepared and is kept thoroughly dry up until the moment of actual use, and provided that all times and temperatures are carefully standardized and precisely controlled.
A major defect with this method is that with time, and especially in the presence of moisture, the labeled hormone becomes permanently bound to the resin and therefore unavailable for binding by the blood serum protein. The combination of a labeled hormone and an exchange resin is therefore entirely unsuitable for use in a complete and self-contained liquid reagent composition that can be prepared and stored for future use.
Eisentraut U.S. Pat. No. 3,666,854 discloses a method for determining thyroid function in which particulate inorganic crystalline materials are employed as sorbent materials, and specifically discloses the use of silicic acid and opal, for example. However, we have found that amorphous silicon dioxide per se is not particularly effective when employed as the sorbent material in a test for determining thyroid function.
SUMMARY OF THE INVENTION
Among the objects of the present invention may be noted the provision of novel radioactive diagnostic reagent compositions for the in vitro determination of thyroid function; the provision of compositions of the character described in the form of an aqueous suspension which contains therein all the essential reagent substances for measuring the unsaturated thyroxine binding capacity of blood serum protein; the provision of compositions of the character described which may be packaged and stored in units of a size just sufficient for testing a single sample of blood serum; the provision of such compositions which remain usable for the effective life of the radioactive isotope contained therein; and the provision of methods for using the aforesaid compositions. Other objects and features of the invention will be in part apparent and in part pointed out hereinafter.
The present invention is thus directed to a diagnostic reagent composition for use in measuring the unsaturated thyroid hormone binding capacity of blood serum. The reagent comprises a buffered aqueous suspension of finely divided, amorphous silicon dioxide which additionally contains a nonionic surfactant and a thyroid hormone substance such as thyroxine tagged or labeled with a radioactive isotope of iodine, the weight to weight ratio of amorphous silica to nonionic surfactant in the suspension being in the range of approximately 10:1 to 50:1. The invention also includes the method of using such a reagent composition in the in vitro determination of thyroid function.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In carrying out the method of the present invention, a measured amount of the blood serum to be tested is mixed with the novel reagent composition of the invention, the amorphous silicon dioxide is separated from the liquid portion of the sample, e.g. by centrifugation, after which the radioactivity of either the solid silicon dioxide residue or the supernatant liquid is determined using a conventional scintillation well counter.
The method is based upon desorption of the labeled hormone from the silicon dioxide carrier by certain proteins, notably thyroxine-binding globulin, in the blood serum. Unlike desorption methods employed in the past, the present method is essentially independent of time and temperature and the reagent composition of the invention is complete and self-contained.
In the novel diagnostic reagent composition of the present invention, the radioactive isotope labeled hormone is releasably bound to the amorphous silicon dioxide which together with the nonionic surfactant serves as a solid carrier. Thus, when serum is mixed with the reagent, the unsaturated binding sites present in the thyroxine-binding globulin of the serum take labeled hormone from the carrier until the binding capacity is substantially saturated. The excess labeled hormone remains bound to the silicon dioxide carrier. This transfer occurs practically instantaneously at ordinary room temperatures, and therefore the method is essentially independent of time and temperature. As soon as convenient, the solid silicon dioxide containing the excess labeled hormone is separated from the liquid portion of the sample which contains the protein bound hormone, i.e. the substantially saturated thyroxine-binding globulin. This is easily and quickly accomplished by centrifugation. Since the total amount of labeled hormone initially present in the reagent composition is known or easily determined, the amount of such hormone taken up by the serum protein can be determined by counting either the supernatant liquid or the separated solid silicon dioxide using a conventional scintillation counter.
Numerous nonionic surfactants suitable for use in the present invention are disclosed in Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Volume 19, pages 531-554. Among those which have been found particularly suitable may be noted polyoxyethylene alcohols, polyoxyethylene sorbitan fatty acid esters, nonylphenoxypoly (ethyleneoxy) ethanol and sorbitan fatty acid esters.
The reagent composition of the present invention is in the form of a buffered aqueous suspension which may be packaged and stored in units just sufficient for a single test and the container in which the method of the invention is carried out may be a test vial of the kind and size customarily used with a conventional scintillation counter.
The labeled hormone may be either L-thyroxine (T-4) or L-triiodothyronine (T-3) tagged or labeled with a radioactive isotope of iodine such as I-125 or I-131. Such hormones are well known and are used in most if not all in vitro methods for measuring thyroid function.
In accordance with the present invention, it has more specifically been found that the employment in the reagent composition of amorphous silicon dioxide, and nonionic surfactant in a (w/w) ratio of approximately 10:1 to 50:1 provides particularly good results as compared to the use of amorphous silicon dioxide alone as the sorbent material.
The following examples illustrate the invention.
EXAMPLE 1
A suspension of 20 g. of microfine precipitated silica ("QUSO G-32" manufactured by Philadelphia Quartz Co.) was suspended in 2000 ml. of a pH 7.3 (± 0.1) buffer solution having the following composition:
______________________________________Tris(hydroxymethyl)aminomethane 48.4 g.HCl 29.8 ml.Water to make 2 liters______________________________________
To this suspension was added an aqueous solution containing 1.0 g. of nonylphenoxypoly (ethyleneoxy) ethanol ("Igepal CO-880" manufactured by Applied Science Laboratories, Inc.). The suspension was thoroughly mixed and then sufficient T-3 labeled with I-131 was added to give between 50,000 - 100,000 cpm/3 ml. in a conventional scintillation counter. The suspension was then dispensed into glass vials, 3.0 ml./vial.
EXAMPLE 2
The reagent vials described in Example 1 are used in the following manner in determining the thyroxine-binding capacity of blood serum protein:
1. Add 0.1 ml. of patient serum to a reaction vial. Also add 0.1 ml. of control serum in a reaction vial.
2. Mix all of the vials by inverting several times or place on a vortex mixer for 10 seconds.
3. Allow the vials to stand for 5 minutes at room temperature.
4. Centrifuge the vials for 5 minutes at 2500 rpm or until the adsorbent is packed.
5. Decant the supernatant fluid, which is discarded, and drain the tubes for 1 minute on a paper towel.
6. Count the vials of patient serum and control serum and calculate the index. ##EQU1##
EXAMPLE 3
Example 1 was repeated except that polyoxyethylene (20) oleyl ether sold under the trade designation "BRIJ 98" by Atlas Chemical Industries, Inc. was used as the nonionic surfactant.
EXAMPLE 4
Example 1 was repeated except that polyoxyethylene (20) sorbitan monolaurate sold under the trade designation "Tween 20" by Atlas Chemical Industries, Inc. was used as the nonionic surfactant.
EXAMPLE 5
Example 1 was repeated except that sorbitan monolaurate sold under the trade designation "Span 20" by Atlas Chemical Industries, Inc. was used as the nonionic surfactant.
The compositions and method described in Examples 1-5 were applied to a wide range of serum samples and the results compared favorably in precision and accuracy with the results obtained using other more time-consuming methods known heretofore.
EXAMPLE 6
The following tests were carried out to determine the comparative results between carrying out the thyroid function determination above described with and without the incorporation of a nonionic surfactant in the diagnostic reagent composition.
The procedure of Example 1 was followed in preparing 100 ml. each of suspensions containing 0.5, 1.0, 3.0 and 5.0% of microfine precipitated silica ("QUSO G-32" manufactured by Philadelphia Quartz Co.) and no nonionic surfactant and in preparing 100 ml. each of suspensions containing the same silica and the nonionic surfactant nonylphenoxypoly (ethyleneoxy) ethanol ("Igepal CO-880" manufactured by Applied Science Laboratories, Inc.) in the weight by weight ratios of 1:1, 5:1, 10:1, 20:1, 30:1, 40:1, 50:1 and 100:1. The buffer solution of Example 1 was used in preparing these suspensions. The resulting suspensions contained the quantities of labeled triiodothyronine (T3) as described in Example 1. All of the suspensions prepared were dispensed into glass vials, 3.0 ml./vial.
Reaction vials labeled B for "Button" or blank to which no serum was added, were shaken, precounted and placed on a vortex mixer for 10 seconds. They were then spun for 5 minutes at 2500 rpm or until the adsorbent was packed, the supernatant decanted, and the vials drained for a minute on a paper towel before being postcounted. After the addition of 0.1 ml. of serum, the sample vials were mixed, allowed to stand for 2 minutes before being placed on a vortex mixer for about 10 seconds, spun at 2500 rpm for 5 minutes or until the adsorbent was packed, the supernatant decanted and the vials drained for a minute on a paper towel before being postcounted, all as described in Example 2. The percent uptake of labeled triiodothyronine (T3) was calculated by dividing the postcount in cpm by the precount in cpm. The sera used for these tests were MONI-TROL I (normal or euthyroid) and MONI-TROL II (hyperthyroid) synthetic control sera available commercially from Dade Division of American Hospital Supply Corporation. For these tests, the same vials of reconstituted controls were used.
The results are as follows:
______________________________________% Silica mg. Silica/ml. % UptakeConc. Dispersion B I II Δ%, I - II______________________________________ 0.5 5 6.0 15.4 19.1 3.71 10 13.6 23.1 26.2 3.13 30 28.8 42.4 43.5 1.15 50 42.9 56.8 56.1 -0.7 mg. Silica:Ratio Silica: mg. nonionicNonionic Sur- Surfactant/ml. % Uptakefactant (w/w) Dispersion B I II Δ%, I - II______________________________________ 1:1 10:10 25.9 25.0 26.6 1.6 5:1 10:2.0 90.3 74.5 79.1 4.610:1 10:1.0 89.0 58.2 71.3 13.120:1 10:0.5 82.0 44.3 55.3 11.030:1 10:0.333 78.0 36.4 50.0 13.640:1 10:0.25 74.0 33.2 43.5 10.350:1 10:0.2 69.7 33.1 44.5 11.4100:1 10:0.1 48.0 28.9 34.1 5.2______________________________________
With respect to the values reported for B in the first tests with silica only as the sorbent, it is probable that agents normally present in the blood serum which have surfactant characteristics are interacting with the silica to cause higher uptake as to the MONI-TROL I and II sera samples.
The above data indicate rather clearly that the incorporation of the nonionic surfactant in the formulation increases the Δ % or difference in % uptakes between the two MONI-TROL control values. Without an appreciable increase in the differential between the % uptake by these two controls, accurate test results differentiating between normal thyroid function and hyperthyroid or hypothyroid function cannot be achieved.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above methods and compositions 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.
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A complete and self-contained in vitro diagnostic reagent composition for use in determining thyroid function comprises a buffered aqueous suspension of finely divided, amorphous silicon dioxide, having combined therewith a nonionic surfactant and a thyroid hormone substance tagged or labeled with radioisotopic iodine.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the United States national phase under 35 U.S.C. §371 of PCT International Application No. PCT/EP2007/007790, filed on Sep. 6, 2007. That application is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention relate to methods for transmitting payload data, in particular payload data that implement real-time applications and an arrangement for transmitting payload data that in particular implement real-time applications.
2. Background of the Art
Transmission of real-time critical data through a communication network is well known in the art. One application involving such data transmissions is Voice-over-IP (VoIP) Telephony, which is quickly becoming more important, since telephony is shifting more and more to data networks, in particular to the internet.
This shift is associated with an increased risk of harmful attacks in VoIP connections, similar to those observed for some time in data networks. Unlike attacks on regular data connections, VoIP attacks often cannot be detected with certainty until after the payload data have been generated, due to their real-time nature. At that point, the associated nuisances and/or damages have already occurred.
It would be helpful to provide a method and communication device for transmission of payload data that, in particular, implement real-time applications in order to increase security against attacks from unauthorized third parties.
BRIEF SUMMARY OF THE INVENTION
In preferred embodiments of the invented method for transmitting payload data that implement real-time applications between at least one first communication device and at least one second communication device, whereby the payload data will be transmitted as data packets during a communication connection, at least one packet enabling authentication of the first communication device will be embedded during the communication connection in at least one payload-data-transmitting data packet that is directed to a second communication device by the first communication device.
A significant advantage of the invented method is that, due to the inclusion of payload data in the authentication packets, it is possible for the communication device receiving the payload data to continuously determine whether the communication partner really is the identified communication partner. Inclusion in the payload data provides the advantage that just the data alone can be transmitted to the receiving communication device, since although there may be requirements for the header data of payload data packets, there are no requirements regarding the content. Therefore, the invented method provides the added benefit of easy implementation in existing systems. Furthermore, it is suitable for systems where the trustworthiness of the receiving communication device is without question.
Additionally, it provides the advantage, if the method is developed in this way, that during a communication connection, at least one packet enabling authentication of the second communication device will be embedded during the communication connection in at least one payload-data-transmitting data packet that is directed to the first communication device by the second communication device. In this way, both communication devices will be secured by a preferential method according to the invention.
If the first and/or second communication device requests the transmission of authentication-enabling packets upon receiving payload data, this will create a degree of freedom during implementation of the method in that, for example, authentication could be requested at a later randomly selected point in time, or, before the request, an evaluation could be performed to see whether the sending communication partner is actually capable of performing the authentication according to the invention and, if necessary, alternate protective mechanisms could be employed.
Preferably, the first and/or second communication device will examine the data packets for the presence of at least one authentication-enabling packet, and if no authentication-enabling packet is detected, the communication connection will be terminated. This further embodiment has the benefit of easy implementation.
Furthermore, it is preferential for the examination to occur within a defined first time span and the lack of detection to be determined by the end of this time span. This ensures defined states and termination during execution of the method.
Alternatively or in addition, if the authentication-enabling packet is missing, the receiving communication device will request the authentication-enabling packet from the sending communication device, and if the requested packet does not arrive, the communication connection will be terminated. This further embodiment provides the advantage that accidental interruption due to too short time windows or to long transmission times of packets is mostly eliminated, since the sending device will get a second chance due to this explicit query.
Preferentially, the authentication-enabling packet will be embedded as a packet with at least one header field with at least one piece of information characterizing this function, to allow for easy detection within the payload data. Furthermore, a header field provides advanced possibilities for checking the packet.
A more preferred embodiment is to re-embed at predetermined times during the communication connection between the first communication device and the second communication device. This ensures that no attacker will be able to enter between the communication partners at a later time and behave as if it were the other communication device.
Easy implementation is ensured when the determination is made in such a way that re-embedding occurs at equal time intervals.
Alternatively, the determination can be made in such a way that re-embedding occurs at different time intervals, in particular, in pseudo-randomized durations. This makes it difficult for attackers to easily use an authentication packet by successfully spying on the payload data, since in addition to the packet, the attackers would also need the communications partners' shared knowledge about the pseudo-randomized algorithm.
If at least one piece of authentication information is inserted in the authentication-enabling packet such that at every re-embedding the inserted information will be different from the previously inserted information, it will be even more difficult for an attacker to corrupt the communication downstream from the point of interception when intercepting an authentication packet, since the attacker does not have any knowledge about the changing information.
This becomes even more difficult if the authentication-enabling packet is provided with at least one encryption key identification, password and/or information encrypted with a special “PKI” key.
The invented arrangement for transmitting payload data that implement real-time applications between at least one first communication device and at least one second communication device, which are designed in such a way that the payload data are transmitted as data packets during a communication connection, provides means for the execution of the method according to the aforementioned embodiment and provides a preferential physical basis for execution of the method.
Further details of the invention and its advantages will be further described in a first embodiment illustrated in FIG. 1 and a second embodiment of the invention illustrated in FIG. 2 .
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : Schematic of unidirectional embedment of authentication packets in payload data packets;
FIG. 2 : Schematic of bidirectional embedment of authentication packets in payload data packets.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a first embodiment of the invention. It shows a first communication device A; A 1 . . . A 2 and a second communication device B; B 1 . . . B 2 , whereby it is further shown that basically the communication device according to the invention can be a data processing unit, such as a personal computer or a portable computer (laptop, notebook) A 1 ; B 1 with suitable VoIP software, or a special VoIP hardware item such as a VoIP-capable telephone A 1 ;B 2 .
The invention concerns in particular the specific attack where, after establishment of a payload data connection, a voice data stream originating from one of the communication devices A; A 1 . . . A 2 ; B; B 1 ; B 1 . . . B 3 of a subscriber is intercepted and replaced by a manipulated voice data stream which may originate from a human or electronic voice imitator.
Thus the illustrated embodiment is activated at a first point in time T 1 with the establishment of a connection, which may be triggered by the first communication device A; A 1 . . . A 2 , for example, by a call to the second communication device B; B 1 . . . B 2 , which is well known in telephony.
As a result of this call, the illustrated example assumes that a communication connection was established.
Therefore, at a second point in time T 2 , a payload data transmission occurs, which may be from the first communication device A; A 1 . . . A 2 to the second communication device B; B 1 . . . B 2 , or from the second communication device B; B 1 . . . B 2 to the first communication device A; A 1 . . . A 2 .
In this first embodiment, regardless of whether payload data is transmitted in both communication directions A; A 1 . . . A 2 ; or not, a payload data stream will be sent only from the first communication device A; A 1 . . . A 2 , and the invented authentication packets AP A —packets are not shown—will be embedded only in this payload data stream.
It is also feasible to implement this approach in systems or in applications where, for example, the almost real-time transmission of collected data to an evaluation center occurs, as is the case in video and/or audio monitoring of objects via cameras or microphones that are capable of communicating with a central unit.
The authentication packets arriving at the second communication device B; B 1 . . . B 2 will then be extracted accordingly from the respective payload data packets and examined.
For this purpose, the second communication device has knowledge about the form of the authentication information by following the same algorithm to arrive at the information and/or transmission time, or the information and/or points in time are saved in a second communication device, which may be assigned to known communication devices by assignment through a mapping table.
Depending on the verification result, the communication connection is then maintained, and the payload data forwarded for appropriate processing, or the communication is interrupted or the payload data are discarded or forwarded for analysis of an attack.
FIG. 2 shows a second embodiment of the invention. The illustrated arrangement does not differ from the first embodiment, so the identical elements of the first embodiment are identified with the same reference symbols, while the new elements of the invented second embodiment received new reference symbols.
It shows again the first communication device A; A 1 . . . A 2 and the second communication device B; B 1 . . . B 2 , which again are basically a data processing unit, like a personal computer or a portable computer (laptop, notebook) A 1 ; B 1 with suitable VoIP software, or special VoIP hardware item such as a VoIP-capable telephone A 2 ; B 2 .
Again, there is a call at the first point in time T 1 from the first communication device A; A 1 . . . A 2 to establish a communication connection with the second communication device B; B 1 . . . B 2 .
Differently from the previous embodiment, this example provides that upon successful establishment of the communication connection between the first communication device A; A 1 . . . A 2 and the second communication device B; B 1 . . . B 2 at a second point in time T 2 , not only will bidirectional transmission of payload data occur, but also embedment of authentication packets AP A ; AP B , from both the first communication device A; A 1 . . . A 2 , indicated by black rectangles AP A , and the second communication device B; B 1 . . . B 2 , indicated by gray rectangles AP B , in the payload data packets sent by the respective device.
The illustrated examples relate primarily to a VoIP-enabled scenario, however, this invention is in no way limited to these examples. It can be implemented anyplace where real-time critical applications transmit payload data, regardless of whether the transmission is unidirectional (e.g., monitoring) or bidirectional (telecommunications).
In summary, the described embodiments illustrate that the core of the invention is to embed verification packets at predetermined regular or irregular time intervals in payload data stream for authentication and authorization, whereby these are identified as such in the packet header according to a further embodiment and where they generally do not impair the payload data in any way.
Various standardized methods offer the possibility to define such packets, which are identified in the header and are otherwise proprietary prior to final standardization of the invented method.
These packets may include certain sender-specific safety features, such as key identifiers, passwords, information encrypted with a (PKI) key, or similar features.
As described, the receiver will check the receipt and content of the packets and may, if such packets do not arrive or if the content is unsuitable, initiate appropriate actions, like expressly requesting such packets or terminating the connection.
Embodiments of the invention may offer an advantage that routers can route these packets easily, since the described method does not affect the internet protocol level.
A further advantage is that other devices, in particular terminals, will merely discard such packets if the defined packet type is unknown, so that (unsecured) communication is still possible as a fallback resort.
In a further embodiment, the packet content may be modified at predefined time intervals in a pseudo-randomized way that is known only to the partners, in order to prevent such packets from being intercepted and replaced by manipulated ones. Further measures to defend against so-called replay attacks can easily be applied in a preferred further embodiment of the invention.
Further, the invention can be summarized in that verification packets which are specifically identified within the payload connection may be sent either unidirectionally from the first communication device A; A 1 . . . A 2 to the second communication device B; B 1 . . . B 2 , wherein only the second communication device B; B 1 . . . B 2 has the task of checking the validity of the verification packets and responding, if applicable, to invalid or missing packets as described above, or, to overcome the disadvantage of this variation, which is that the first communication device A; A 1 . . . A 2 has no knowledge of the authenticity of the second communication device B; B 1 . . . B 2 , by sending bidirectionally, in which variation both the first communication device A; A 1 . . . A 2 and the second communication device B; B 1 . . . B 2 have the task of verifying the validity of the opposite side's verification packets and responding in the described way, so that mutual control is implemented.
According to embodiments of the invention, it is not necessary to check, in particular, a voice data stream continuously for accuracy and consistency of the speaker-characteristic frequency patterns or speech characteristics, since the invention provides more or, depending on application frequency, less dense partner verification during the payload data exchange, which is completely adequate for high-probability detection of an attack, in particular a “Man in the Middle” attack.
Compared to the methods known in the state of the art, which execute speaker verification during VoIP connections that takes place solely during establishment of the connection, i.e. prior to the actual payload data exchange, the invention provides a solution for simple implementation of protection.
This is shown by a comparison with the “Man-in-the-Middle” defense method well known in the state of the art, where key data are exchanged at or prior to establishing the payload data connection, e.g., by exchanging key data to authenticate the partners and to encrypt the payload data, which is certainly an effective method, but has the disadvantage that both partners must have similar, technically extensive equipment.
In the event that at least one partner does not possess such technically extensive equipment, the invention provides a solution that is less technically demanding, but yet guarantees continuous partner verification during the payload data connection.
Further it provides the advantage of backward compatibility with existing standardized methods for payload data exchange.
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The invention relates to a method for transmitting user data, particularly user data realizing real-time applications, between at least one first communication device and at least one second communication device, the user data being transmitted as data packets during a communication connection, wherein during the communication connection at least from the first communication device at least one packet enabling an authentication of the first communication device is embedded in at least one of the data packets transmitting the user data and directed at the second communication device. The invention furthermore relates to an arrangement for carrying out the method.
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BACKGROUND OF THE INVENTION
The present invention relates to livestock watering devices and in particular to those devices which are equipped with heating devices.
Previous generations of livestock waterers consisted of open tubs in barnyards or pens. There livestock could access the water as needed. Improvements were then made to the cattle waterers which allowed the tubs to be filled automatically. Although the automatic fillers solved a number of problems with the waterers, problems relating to freezing persisted. Specifically, in sub-freezing climates, the water in the waterer is susceptible to freezing. In order to abate this problem, farmers began to use heaters to warm the water to above freezing. Although heaters aided in keeping most of the water in a liquid state, freezing still occurred at the air-water interface. Additionally, the costs of heating the waterers became more expensive. Improvements to better insulate the waterers led to insulation material utilized in the outer shell of the waterer and inventions directed at insulating the upper surface of the water itself. U.S. Pat. No. 4,646,687 discloses a waterer with a circular cover or lid which floats upon the water's surface. The lid could be manipulated by the animal in such a way to allow access to the water beneath. Other patents sized the lid to avoid its freezing to the surrounding opening. U.S. Pat. No. 4,883,022 implemented guide rails anchoring the cover to the waterer while still allowing the animals access to the water below. The guide rails assisted in preventing the animals from being able to physically remove the lids from the waterer.
With conventional lids, movement of the lids by animals seeking to drink creates turbulence and splashing of water from the waterer. This wastes water and also creates a muddy ground surface around the waterer or leads to ice build up on the outside of the waterer. The shape of previous lids made them prone to generating wave action within the waterer. Wave action causes water to be lost which in turn add extra costs in the replacing of the water as well as heating of the replacement water.
One other shortcoming is the placement of the heater within the waterer. Traditionally, the heater is placed in a protected central location away from the basins accessible by the animals so that the animals will not damage the heating element. The heat created by the heating element must travel from the central location of the waterers to the basins and may be sufficiently dissipated before water in the basins is sufficiently warmed to prevent freezing in frigid weather conditions.
BRIEF SUMMARY OF THE INVENTION
An improved livestock waterer includes a base which provides one or more basins for containing water which may be accessed by an animal seeking water. The basins are separated by an enclosure which is an integral part of the base. The enclosure may house heater and water supply elements and may also include a central water container from which water may circulate to the basins through ports connecting the basins to the central water container.
Each of the basins is provided with a polymeric or other non-metal floating lid. Each lid is constructed as a hollow enclosure in which air is trapped. The upper surface of each lid is in the form of a dome or convex curve so that water will not remain standing on the upper surface. The underside of each lid includes a number of baffles which reduce wave action on the surface of the water below the lid as the lid is depressed or displaced by an animal seeking water below the lid. By reducing turbulence below the lid, less chance exists that water will splash from the basin during drinking activity, or when an animal experiments with the lid out of curiosity.
Heating elements may be placed within the water basins. Each heating element is supported on a post which is formed integrally with the base such that the post will stand upright upon the bottom of a water basin.
A primary object of the invention is to provide an improved livestock waterer which reduces the incidence of splashing from the waterer when an animal displaces the lid floating on the water made available to the animal.
Another object of the invention is to provide an animal waterer which is less susceptible to ice accumulation on the floating lids overlying the water within the waterer.
A further object of the invention is to provide an improved mounting structure for a heater element stationed within the water in the waterer.
Yet another object of the invention is to provide an animal waterer which always maintains water covering the heating elements.
These and other objects of the invention will be apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a perspective view of an embodiment of the waterer having elongate water basins separated by a central enclosure.
FIG. 2 is a top view perspective of the lid of the embodiment of FIG. 1 .
FIG. 3 is a bottom view perspective of the lid of the embodiment of FIG. 1 .
FIG. 4 is a three-dimensional front perspective of a second embodiment of the invention.
FIG. 5 is a cross-sectional view taken along line 5 - 5 of FIG. 4 , shown with water in the waterer.
FIG. 6 is a bottom view perspective of the lid for each of the basins of the livestock waterer of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, one embodiment of the livestock waterer 4 can be seen in perspective in FIG. 1 positioned to demonstrate the three dimensional shape of the structure. Mounting points 6 can be used to secure the invention to a surface such as a concrete platform with the use of a selected type of mounting hardware. Mounting recesses 8 allow easier access to the mounting points 6 and ease in the facility of accessing the chosen mounting hardware.
Livestock waterer 4 includes a housing 12 which comprises two basins 10 separated by an elevated enclosure 7 . The housing 12 further comprises front and rear longitudinal sidewalls 5 , 13 and opposing end walls 9 , 11 . Sidewalls 5 , 13 , end walls 9 , 11 and elevated enclosure 7 are formed integrally of polymeric material. Lids 14 substantially cover the opening of basins 10 . Lids 14 are buoyant, preferably hollow and are made from a polymeric material. Lids 14 preferably float on the surface of water contained within each basin 10 . Pass through openings 16 in the lids 14 allow guides 18 to pass through the lids 14 . Guides 18 each consist of elongate vertically disposed rods which extend into basin 10 and are fixed at the bottom of basin 10 . Guides 18 are also retained in an upstanding orientation by their attachment to guide mounts 20 atop opposing end walls 9 , 11 or by attachment to the sidewalls 15 of elevated enclosure 7 . Guides 18 are spaced apart from basin sides a small distance. Preferably one guide 18 is located along each opposite side of the basins 10 . A top access panel 22 on the top of the elevated enclosure 7 is removable to access equipment such as a float valve (not shown) within elevated enclosure 7 . Recess 25 facilitates removal of the top access panel 22 . Side access panel 26 is selectively removable from the livestock waterer 4 and provides access to the interior of the elevated enclosure 7 . Plugs 28 are received in openings 30 in end walls 9 , 11 to seal openings 30 which are in communication with the basins 10 . The plugs 28 are selectively removable and once removed, allow water to drain from the basins 10 .
Details of the structure of each lid 14 may be seen in FIGS. 2 and 3 . Each lid 14 includes an upper surface 50 and an underside 70 . Upper surface 50 of each lid 14 is preferably convex in shape and upper surface 50 may be formed as a segment of a cylinder or may otherwise be domed in shape. Peripheral regions 57 of upper surface 50 may be planar though they are not required to be so. Peripheral regions 57 of upper surface 50 are preferably kept minimal in area to provide little planar surface on which water may collect. Lid 14 is preferably hollow with upper surface 50 sealed at side edges 80 , 82 , 84 and 86 to underside 70 so that air is trapped within lid 14 and it is buoyant.
As seen specifically in FIG. 3 , the underside 70 of lid 14 is substantially planar. A baffle system 61 depends from the underside 70 . Baffle system 61 comprises transverse walls 60 , 68 and longitudinal walls 62 , 66 , each of which are generally perpendicular to the underside 70 of lid 14 . Bottom edges 74 of baffle system 61 may be parallel to underside 70 and may extend approximately one to five (preferably two to three) inches from underside 70 of lid 14 . The baffle system 61 may be integral with the other structures of lid 14 . Longitudinal walls 62 , 66 of baffle system 61 extend substantially the length of underside 70 but are interrupted by gaps 71 therein. In the preferred embodiment transverse walls 60 , 68 interconnect longitudinal walls 62 , 66 at a substantial perpendicular near distal ends 64 , 69 of longitudinal walls 62 , 66 . Distal ends 64 , 69 of longitudinal walls 62 , 66 extend past their intersections with transverse walls 60 , 68 a short distance which, in the case of a lid 14 which is of a total length of approximately thirty-six inches, may be one to two inches. Distal ends 64 , 69 may be inclined from bottom edge 74 at twenty to seventy degrees and preferably from thirty to sixty degrees. Proximal edges 72 , 73 of longitudinal walls 62 , 66 extend approximately ten to twelve inches past transverse walls 60 , 68 in the case of a lid 14 of length in the range of thirty-six inches. Longitudinal walls 62 , 66 are longitudinally aligned with proximal ends 72 , 73 thereof spaced apart from one another to form gaps 71 . Proximal ends 72 , 73 may be inclined at ten to eighty degrees from perpendicular to underside 70 preferably at 30 to 60 degrees. Gaps 71 between proximal ends 72 , 73 of longitudinal walls 62 , 66 are critical in providing turbulence damping so that air is not trapped between longitudinal walls 62 , 66 and transverse walls 60 , 68 below lid 14 . The gaps 71 separate baffle system 61 into first set of baffles 63 and a second set of baffles 67 . The second set of baffles 67 mirrors the first set of baffles 63 in the preferred embodiment. The baffle system 61 interrupts and abates the wave motion of the water caused when an animal manipulates lid 14 to access the water. The baffle system 61 may be formed on underside 70 as an integral part of lid 14 and each wall 60 , 62 , 66 and 68 may be hollow.
A second embodiment of the invention is seen in FIG. 4 and FIG. 5 . Livestock waterer 104 shares many of the structures and characteristics of the embodiment detailed in FIGS. 1-3 . Mounting recesses 108 allow access to mounting points 106 which can be fitted with hardware to anchor the livestock waterer 104 to a ground surface. Livestock waterer 104 contains basins 110 set in housing 112 . The housing 112 further comprises front and rear longitudinal sidewalls 105 , 113 and opposing end walls 109 , 111 . Recess 125 allows a top access panel 122 to be removed easier. The top access panel 122 and side access panel 126 are selectively removable and allow access to the interior of the elevated enclosure 107 .
A lid 114 substantially covers each of basins 110 . Openings 116 in lids 114 allow guides 118 to pass through lids 114 . Guide mounts 120 extend from the sidewalls 105 , 113 and secure the guides 118 . Guides 118 are further secured by being anchored to bottom 141 of basins 110 .
Now referring to FIG. 5 , a cross-sectional view shows more detail of the second embodiment livestock waterer 104 . Cavity 140 within the livestock waterer 104 extends to the bottom 141 of basin shelf 142 . Housing 112 comprises end walls 109 , 111 which cooperate with basin shelf 142 and longitudinal sidewalls 105 (seen in FIG. 4 ), 113 to define cavity 140 . Sidewalls 115 of elevated enclosure 107 , end walls 109 , 111 , longitudinal sidewalls 105 , 113 and basin shelf 142 cooperate to define basins 110 which are elevated above a ground surface. Longitudinal sidewalls 105 , 113 , sidewalls 115 of elevated enclosure 107 and end walls 109 , 111 can be seen to be an integral one-piece polymeric structure formed by molding. A water supply pipe (not shown) may traverse cavity 140 and pass through basin shelf 142 to enter central fill tub 146 . Float compartment 144 adjoins central fill tub 146 and provides a location far a float valve (not shown) from which central fill tub 146 is filled. The water enters the basins 110 via ports 148 which connect basins 110 with central fill tub 146 . Lids 114 are buoyant and are supported on water surface 132 within basins 110 . Therefore, lids 114 rise with the addition of water to the basins 110 . Lids 114 slide vertically on guides 118 as water is added to or removed from the basins 110 and as animals seeking water depress lids 114 to gain access to water below lids 114 .
Once basins 110 are filled to a desired level with water, a float valve (not shown) located in elevated enclosure 107 closes to prevent further inflow of water from a water source. An animal gains access to the water by pushing lid 114 downward. As the animal exerts downward force, the lid 114 partially submerges and water rolls over upper surface 150 . Once the animal ceases to exert downward force on lid 114 , water rolls off convex lid 114 and the lid 114 returns to its floating position on top of water contained in basin 110 .
Again referring to FIG. 5 , basin floor 154 contains elements aiding in the heating of the water contained in basins 110 . Post 152 extends from basin floor 154 and may be integrally formed with basin floor 154 . In the preferred embodiment, post 152 is cylindrical. The shape and size of post 152 is selected such that heater 156 may attach to the periphery of post 152 . The heater is positioned in the middle of basin floor 154 in such a way so it cannot be accessed by an animal drinking from the livestock waterer 104 .
As water is removed from the livestock waterer by the animals or through evaporation, the lids 114 descend toward the basin floor 154 . The baffle system 161 of lids 114 of livestock waterer 104 depend from underside 170 of lids 114 to a distance of at least the height of post 152 . This minimal length assures water will always sufficiently cover the heater 156 and minimize overheating of heater 156 .
Again referring to FIG. 4 and FIG. 5 , the basin floor 154 may be sloped to provide enhanced emptying and cleaning of the livestock waterer 104 . Once plugs 128 are removed from openings 130 , water drains from basins 110 . The top access panel 122 and side access panel 126 allow a person to more easily access a heating element or water supply within the housing 112 .
FIG. 6 discloses a lid 114 for the embodiment of the livestock waterer 104 of FIG. 4 . Lid 114 comprises an upper convex surface 150 and an underside 170 which is substantially planar. Baffle systems 161 depend from underside 170 and each comprises a transverse wall 163 joined perpendicularly to longitudinal walls 162 and 166 which are spaced apart. Each of longitudinal walls 162 and 166 inclines from its attachment to transverse wall 163 to the underside 170 , leaving a small gap between baffle systems 161 approximately midway along underside 170 . Walls 162 , 163 , 166 each preferably depends at a substantial perpendicular from underside 170 .
In the foregoing description, the container has been described in connection with preferred embodiments, but it should be understood that the description does not intend to limit the container to the embodiments described. Rather, this description is intended to include such alternatives, modifications and equivalents as may be included in the sphere and scope of this invention, as more particularly set forth in the claims.
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A livestock waterer for use in frigid climates includes a lid which floats on the surface of the water in each basin of the waterer. The lid is hollow with a convex upper surface and with baffle walls depending from the underside of the lid. The baffle walls interrupt wave action on the surface of the water created by depression of the lid into the water when an animal presses down on the lid to gain access to the water. The floor of each basin is provided with an integrally formed mounting post to support a heater within the basin. The baffles walls prevent exhaustion of water within the basin thereby preserving submersion of the heater at all times.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/417,792, filed Oct. 11, 2002.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
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 by the terms of a contract awarded by The Defense Advanced Research Agency.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to analyzing organisms such as bacterial spores based on their soluble polypeptides and more particularly to the identification of organisms such as bacterial spores based on peptide fragments of their soluble polypeptides.
(2) Description of Related Art
A number of approaches have been used in the past for applying the analytic power of mass spectrometry to microorganisms (Fenselau and Demirev, Mass Spectrom Rev 20, 157). Among these, electrospray ionization and matrix assisted laser desorption mass spectrometry have provided access to cellular proteins as biomarkers. In many cases proteins have first been isolated from other bacterial material for subsequent analysis by enzymatic, chromatographic and mass spectral procedures (Harris and Reilly, Anal Chem 74, 4410, 2002; Cargile, McLuckey and Stephenson, Anal Chem 73, 1277, 2001; Zhou et al, Proteomics 1, 683, 2001; Krishnamurthy et al, J. Toxicol. Toxin Rev 19, 95, 2000; Xiang et al, Anal Chem 72, 2475, 2000; Arnold and Reilly, Anal Biochem 269, 105, 1999; Holland et al Anal Chem 71, 3226, 1999; Yates and Eng, U.S. Pat. No. 5,538,897; Dai et al, Rapid Commun Mass Spectrom 13, 73, 1999; Liu et al, Anal Chem 70, 1797, 1998; Despeyroux, Phillpotts and Watts, Rapid Commun Mass Spectrom 10, 937, 1996; Cain et al, Rapid Commun. Mass Spectrom 8, 1026, 1994). Isolated proteins were cleaved to peptides, the peptides were partially sequenced by tandem mass spectrometry, and the parent proteins were identified by standard protein and genome database searches. The bacteria species were characterized from the database as the source of the proteins. In other cases researchers have undertaken to analyze protein biomarkers without a separation step (Claydon et al Nature Biotechnol. 14, 1584, 1996; Demirev and Fenselau PCT/US 99/27191; Holland et al, Rapid Commun. Mass Spectrom 10, 1227, 1996; Krishnamurthy, Ross and Rajamani, Rapid Commun. Mass Spetrom 10, 883, 1996; Krishnamurthy U.S. Pat. No. 6,177,266). The sample is lysed on the mass spectrometry sample holder (in situ) and proteins are desorbed directly by matrix assisted laser desorption ionization (MALDI). The spectrum of the mixture of proteins detected can be matched to a carefully prepared library of microbial mass spectra (Conway et al, J. Mol. Microbiol Biotechnol. 3, 103, 2001; Jarman et al, Anal Chem 72, 1217, 2000), allowing distinction of the species, or the microorganism can be characterized by matching the masses of the suite of proteins observed to protein masses predicted from the genome (Demirev et al, Anal Chem 73, 4566, 2001; Pineda et al, Anal Chem 72, 3739, 2000; Demirev et al, Anal Chem 71, 2732, 1999; Demirev and Fenselau PTC/US99/27191).
More recently enzymatic cleavage of proteins on the sample holder for direct analysis of peptides (Yao, Demirev and Fenselau, Anal Chem 74, 2529, 2002; Yao and Fenselau, Rapid Commun Mass Spectrom 16, 1953, 2002) has been proposed to provide a simple rapid analysis of simple viruses. Applying this strategy to more complex microorganisms ( Escherichia coli and Erwinia herbicola ) has revealed that indiscriminant enzymatic digestion of proteins in a microorganism, without a fractionation step, produces a large mixture of peptides, poor signal to noise ratios, poor sensitivity for tandem mass spectrometry (sequencing) experiments, and poor reproducibility. Also see “Rapid Microorganism Identification by MALDI Mass Spectrometry and Model-derived Ribosomal Protein Biomarkers” Antoine et al., J. Lin, Anal. Chem. 75 (2003) pp 3817-3822; U.S. Pat. No. 6,558,946 to Krishnamurthy and U.S. Pat. No. 6,177,266 to Krishnamurthy et al.; and U.S. Patent Application 20030027231 to Bryden et al.
Among the microorganisms, spores of the genus Bacillus are monitored as important targets in battle spaces, subways and buildings, counter-terrorism activities, and in some medical diagnosis. Direct desorption of biomarker proteins from spores has been challenging, as the outer spore coat is strongly resistant to solvents. Abundant proteins, however, are present within the spore core. These proteins can be extracted from spores by treatment with 1N H; 1 HCl, and hence they are referred in the art to as small, acid-soluble proteins (SASP). Their sequences are different for different spores (Hathout et al, Applied Environ. Microbiology 69, in press, 2003).
Also see WO 02/40678 A1 to Fairhead for a detailed description of small acid-soluble spore proteins, which is hereby incorporated by reference in its entirety.
BRIEF SUMMARY OF THE INVENTION
This invention combines selective solubilization of proteins such as SASPs on a sample holder, with rapid enzymatic digestion in situ, partial sequencing by mass spectrometry and database searching to characterize organisms such as Bacillus spores, that may be contained in mixtures, and to distinguish closely related species and strains.
Some embodiments of this invention are directed to a method of analyzing single cell organisms or microorganisms, comprising the steps of:
preparing a sample of at least one single cell organism or microorganism;
adding a solvent to said sample to extract small, acid-soluble proteins from the sample;
digesting the small, acid-soluble proteins, with a proteolytic enzyme or with a chemical reagent that cleaves proteins at specific residues, to produce peptide fragments; and
subjecting the peptide fragments to mass spectrometry or tandem mass spectrometric analysis.
In some embodiments of this invention, the single cell organism or microorganism is at least one member selected from the group consisting of bacterial spores, Gram positive vegetative bacteria, Gram negative vegetative bacteria, virus, fungus, single cell parasites, pollen and any mixtures thereof.
In some embodiments of this invention, the solvent is at least one member selected from the group consisting of an acid, acetic acid, trifluoroacetic acid, formic acid, nitric acid, hydrochloric acid, hydrofluoric acid, methanol, ammonium acetate and any mixtures thereof.
In some embodiments of this invention, the proteolytic enzyme is selected from the group consisting of trypsin, chymotrypsin, pepsin, subtilisin, papain, elastase, S. aureus V8, Lys-C endoproteinase, Arg-C endoproteinase, and Glu-C endoproteinase; or the chemical cleaving agent is selected from the group consisting of BNPS-skatole and cyanogen bromide. The proteolytic enzyme can be immobilized, for example covalently bonded to tiny beads or some other surface so that the enzyme does not “cut” itself up. Also, any protease could be used in this invention.
In some embodiments of this invention, the mass spectrometry can be conducted, for examples, with a matrix-assisted laser desorption ionization, atmospheric matrix assisted laser desorption, medium pressure matrix assisted laser desorption, or with electrospray/nanospray ionization. Lasers of any wavelength in the infrared and ultraviolent ranges may be used.
In some embodiments of this invention, after a step of subjecting the peptide fragments to mass spectrometry, the sequences are determined for at least some of the peptide fragments.
In some embodiments, this invention is directed to a method of distinguishing bacterial spores, comprising the steps of:
preparing a bacterial spore sample on a mass spectrometry sample holder;
adding an acid to said sample to extract small, acid-soluble proteins from the sample;
digesting the small, acid-soluble proteins with proteolytic enzyme to produce peptide fragments;
subjecting the peptide fragments to mass spectrometry;
comparing results of the mass spectrometry of the peptide fragments with results of mass spectrometry for known bacterial spore samples, proteins or peptides; and
identifying the bacterial spore sample by matching the results of the mass spectrometry of the peptide fragments with results of mass spectrometry for peptide fragments from digested small, acid-soluble proteins from at least one bacterial spore sample having a known identity, or with results generated in silico, based on the protein or genome sequence, the known specificity of the enzyme, and/or widely known guidelines for fragmentation of peptides in mass spectrometry and tandem mass spectrometry.
In some embodiments of this invention, the bacterial spore sample contains spores from at least one member of the Bacillus genus.
In some embodiments of this invention, in a step of identifying, the results of the mass spectrometry of the peptide fragments of the sample spores are compared with the results of mass spectrometry of peptide fragments of spores of small, acid-soluble proteins previously observed or predicted in silico from at least one Bacillus spore species and strain selected from the group consisting of B. anthracis Sterne, B. cereus T strain, B. thuringienesis Kurstaki, B. mycoides, B. subtilis strain 168 (ATCC #23857) and B. globigii.
In some embodiments of this invention, in a step of identifying, the sample is determined to contain one Bacillus spore species and strain selected from the group consisting of B. anthracis Sterne, B. cereus T strain, B. thuringienesis Kurstaki, B. mycoides, B. subtilis strain 168 (ATCC #23857) and B. globigii.
In some embodiments of this invention, in a step of identifying, the sample is determined to contain at least one Bacillus spore species and strains selected from the group consisting of B. anthracis Sterne, B. cereus T strain, B. thuringienesis Kurstaki, B. mycoides, B. subtilis strain 168 (ATCC #23857) and B. globigii.
In some embodiments of this invention, in a step of identifying, the sample is determined to contain at least two Bacillus spore species and strains selected from the group consisting of B. anthracis Sterne, B. cereus T strain, B. thuringienesis Kurstaki, B. mycoides, B. subtilis strain 168 (ATCC #23857) and B. globigii.
In some embodiments of this invention, the bacterial spore sample is a non-purified preparation.
In some embodiments of this invention, the acid is at least one acid selected from the group consisting of organic acids and inorganic acids.
In some embodiments of this invention, the mass spectrometry is matrix-assisted laser desorption ionization time-of-flight mass spectrometry.
In some embodiments of this invention, the acid is an acid selected from the group consisting of acetic acid, trifluoroacetic acid, formic acid, nitric acid, hydrochloric acid, and hydrofluoric acid.
In some embodiments of this invention, an immobilized trypsin proteolytic enzyme is utilized.
In some embodiments, this invention is directed to a method of identifying a Bacillus species and strain in bacterial spores, comprising the steps of:
preparing a bacterial spore sample on a matrix-assisted laser desorption ionization time-of-flight mass spectrometry sample holder;
adding trifluoroacetic acid to said sample to extract small, acid-soluble proteins from the sample;
digesting the small, acid-soluble proteins with trypsin to produce peptide fragments;
subjecting the peptide fragments to matrix-assisted laser desorption ionization time-of-flight mass spectrometry including post source decay or collisional activation;
subjecting the peptide fragments to matrix-assisted laser desorption ionization on a tandem mass spectrometer consisting of an ion trap interfaced to a time-of-flight analyzer;
comparing results of the mass spectrometry of the peptide fragments with results or predicted results of mass spectrometry for known bacterial spore samples;
identifying the bacterial spore sample as containing spores of at least one Bacillus species and strain by matching the results of the mass spectrometry of the peptide fragments with results or predicted results of mass spectrometry for peptide fragments from digested small, acid-soluble proteins from at least one bacterial spore sample having a known Bacillus species and strain.
In some embodiments, this invention is directed to a method of preparing a library of mass spectrometry data for single cell organisms or microorganisms, comprising the steps of:
a) preparing a sample of at least one single cell organism or microorganism; b) adding a solvent to said sample to extract small, acid-soluble proteins from the sample; c) digesting the small, acid-soluble proteins with proteolytic enzyme to produce peptide fragments; d) subjecting the peptide fragments to mass spectrometry; e) repeating steps a) through d) for additional organisms or microorganisms; f) storing data results from the mass spectrometry for each organism or microorganism in an accessible location to form a library of said data results.
In some embodiments, this invention is directed to media comprising a database or protein or gene sequences of small, acid-soluble proteins determined for a plurality of different types of Bacillus spores.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Embodiments of this invention will now be described in detail with reference to the attached Figures, in which:
FIG. 1 shows a strategy for rapid identification of Bacillus spores and their mixtures by spore lysis on the sample holder, in situ proteolysis, MS n analysis and database searching;
FIG. 2 shows MALDI-TOFMS spectra from polypeptide ions ( 2 a ) and tryptic peptide ions ( 2 b ) generated in situ from B. anthracis Sterne spores;
FIG. 3 shows MALDI-TOFMS spectrum of peptide ions generated in situ from a 3:1 spore mixture of B. thuringiensis and B. globigii;
FIG. 4 shows PSD spectra from peptide ions at m/z 1929 ( 4 a ) and m/z 1940 ( 4 b ) derived from a 3:1 spore mixture of B. thuringiensis and B. globigii;
FIG. 5 shows MALDI-TOFMS spectrum of tryptic peptides generated in situ from a 1:1 spore mixture of B. anthracis sterne and B. thuriengiensis;
FIG. 6 shows post source decay mass spectrum of the tryptic peptide at m/z 1519;
FIG. 7 shows MALDI spectra of tryptic digests generated on probe from vegetative cells of B. subtilis 168 by enzymatic proteolysis for 5 and 20 min; and
FIG. 8 shows fragmentation spectra of ions to demonstrate the high extent of sequence-specific information achievable by MALDI-PSD analysis.
DETAILED DESCRIPTION OF THE INVENTION
This invention combines selective solubilization of a limited set of proteins, such as SASPs, on a sample holder, with rapid enzymatic digestion in situ, tandem mass spectrometry and database searching to characterize organisms such as Bacillus spores, Gram positive vegetative bacteria, Gram negative vegetative bacteria, viruses, fungi, single celled parasites and other single celled organisms, that may or may not be contained in mixtures, and to distinguish such organisms including closely related species and strains.
Some embodiments of this invention provide identification of Bacillus spores based on the family of small acid soluble proteins abundant in each spore. Selective chemical solubilization is combined in situ with rapid specific cleavage, partial peptide sequencing by mass spectrometry and database searching. Specificity is enhanced by the construction of a limited database comprising small acid soluble proteins. An example approach is summarized in FIG. 1 , which shows a strategy for rapid identification of Bacillus spores and their mixtures by spore lysis on the sample holder, selective solubilization, in situ proteolysis, MS n analysis and database searching.
The method is straightforward and does not require fractionation or protein isolation steps. Spore samples can be prepared directly, for example, on a MALDI sample slide in less than about 3 to 40 min as described below.
To the spore sample on the MALDI sample holder about 5 to 30%, for example 10% trifluoroacetic acid (TFA) in water is added. Other solvents including, for examples, methanol and aqueous ammonium acetate as well as inorganic and organic acids including acetic acid, formic acid, nitric acid, hydrochloric acid, hydrofluoric acid, and mixtures containing these solvents can and have been used successfully.
The solvent is selected to extract a limited, reproducible set of proteins from the sample. For example, a solvent can be selected that extracts a limited number of proteins, preferably 1-15 proteins, and more preferably 1-10 proteins, out of hundreds or thousands of proteins in the sample, while the remainder of the proteins are precipitated. The limited number of different proteins extracted can vary depending on the solvent and sample, but the number preferably ranges from 1-15, or any number or range within that range, such as 5-6. The set of proteins extracted is reproducible since each time a specific sample is treated with a specific solvent, the same number and set of proteins should be extracted.
The solution is allowed to dry before a proteolytic enzyme, such as trypsin immobilized on agarose beads, is added in buffer solution. Incubation (about 1 to 25 min) can be carried out in a closed or humidified chamber to control evaporation.
The product mixture can then be dried, and the digestion can be stopped, for example by adding, 0.5 μl of trifluoroacetic acid solution (1% in water), or by using any other method to denature the enzyme. In embodiments of this invention using MALDI, an appropriate MALDI matrix is added, for example a solution of α-cyano-4-hydroxycinnamic acid solution, 50 mM in 70% acetonitrile/0.1% trifluoroacetic acid to the digested spore sample to enable laser desorption of the peptide products. Of course any MALDI matrix could be used, such as ice.
Following the above method, successful production of tryptic peptide products has been confirmed by the present inventors with a MALDI time-of-flight mass spectrometer (Kratos MALDI 4) operating in linear mode; at 20 kV accelerating voltage and a delay time of 0.3 μs.
The feasibility of the method is demonstrated using a high performance time-of-flight mass spectrometer with a curved field reflectron (Shimadzu Biotech Axima-CRF), operated in the reflectron positive ion mode. Sequence specific information on peptides is provided by postsource decay analysis. Also with MALDI on a hybrid mass spectrometer including a quadrupole ion trap interfaced to a time-of-flight analyzer and using collisional activation to promote fragmentation of selected peptides.
Although the method of this invention is described with reference to MALDI, the method of this invention is compatible any type of mass spectrometry, such as with a MS/MS capable mass analyzer equipped with a MALDI ionization source. In addition to spontaneous (metastable) decomposition detected as post source decay, decomposition induced by collisions with a partial pressure of neutral gas, or various kinds of reactive collisions may also provide fragment or sequence ions for the database search.
In the MALDI process singly charged ions are formed primarily. Thus, MALDI mass spectra of even complex samples such as microorganisms are easily interpretable in terms of mass determination. Previous MALDI-MS studies focused on the analysis of characteristic biomarkers to identify bacterial spores. Since biomarker mass spectra are influenced by cell growth conditions and sample preparation methods, the identification process can be complicated (Demirev et al, Anal Chem 71, 2732, 1999).
In this invention, treatment of whole single cell organisms, such as and preferably bacterial spores, by acid selectively releases the small acid soluble spore protein family. Digestion of this limited set of proteins by a proteolytic enzyme, such as trypsin, and searching a protein/genome database provides a sensitive and reliable approach for identification of Bacillus spores. The use of a database limited to the small acid spore proteins further enhances the significance of matches.
Experiment 1.
An aliquot of 0.8 μl aqueous suspension of B. anthracis Sterne spores (non infectious veterinary strain) (2.5 mg/ml) was placed onto a MALDI sample holder and mixed with 1.2 μl diluted TFA (10% in water). The mixture was allowed to air dry before addition of 1 PI of trypsin immobilized on agarose beads in 25 mM ammonium bicarbonate buffer solution. The sample was incubated for 25 min covered within a humidification chamber for digestion. By allowing the sample to dry and adding 0.5 μl of TFA solution (0.1% in water), digestion was stopped. An aliquot of 0.8 μl of α-cyano-4-hydroxycinnamic acid matrix solution (50 mM in 70 acetonitrile/0.1% TFA) was placed on the digested spore sample for MALDI mass spectrometric analysis.
FIG. 2 a shows the mass spectrum of B. anthracis Sterne spores as a result of on-slide spore lysis using 10% TFA. Ion signals at 6680 Da, 6835 Da, and 7083 Da have been previously identified as acid-soluble spore protein biomarkers from this spore species (Hahout, et al, Applied Environ. Microbiology, 69, in press, 2003). Digestion of acid treated B. anthracis Sterne spores as described before results in mass spectra showing intense peptide fragments of these specific biomarkers ( FIG. 2 b ).
Ion signal intensities of tryptic peptides generated in situ are as much as 100 times more intense than corresponding protein biomarker signals by employing comparable experimental conditions. Since MALDI-TOFMS analysis of tryptic peptides can be readily performed in, the reflectron ion mode, mass resolution and accuracy is increased compared to protein profiling. A compilation of tryptic peptides generated in situ from a selection of Bacillus spore species is presented in table 1.
TABLE 1 Compilation of peptide fragment ions generated in situ from various Bacillus sores. Bacillus spore species and strain Observed [M + H]+ ions* of tryptic peptides B. anthracis Sterne 1488, 1518, 1594, 1940, 1956, 1972, 2007, 2047, 2259 B. cereus T strain 1431, 1489, 1505, 1535, 1595, 1929, 1940, 1956, 1972, 2259, 2275 B. thuringiensis 1431, 1489, 1535, 1595, 1940, 1956, 1972 Kurstaki B. mycoides 1481, 1535, 1595, 1956, 1972 B. subtilis strain 168, 802, 817, 920, 1322, 1338, 1419, 1640, 1881, ATCC # 23857 2286, 2442, 2784, 2842 B globigii 1817, 1929, 2557, 2687 2785 2828 *average masses
Experiment 2
To enhance sample complexity, and therefore, relate to problems often encountered under field conditions, mixtures of two different Bacillus spore species were analyzed. As an example, the mass spectrum of tryptic peptides generated in situ from a 3:1 mixture of B. thuringiensis and B. globigii spores is shown in FIG. 3 . No ion signal suppression of peptide fragments was observed in the MALDI-TOFMS spectrum with respect to peptide mass spectra generated from a single Bacillus spore species. This reflects the selective and predictable solubilization of only a limited set of proteins from each kind of spore. Characteristic peptide ions for B. thuringiensis spores are detected at m/z 1431, m/z 1489, m/z 1535, m/z 1595, m/z 1940, m/z 1956, and m/z 1972, whereas ions at m/z 817, m/z 1929, m/z 2557, m/z 2687, m/z 2785, m/z 2828 relate to B. globigii spores (see Table 1).
This invention moves beyond simple proteolytic peptide mass mapping, however, by providing sequence specific information on many individual peptides. In this experiment, sequence specific information was obtained from analyzing metastable decay processes of ions in a time-of-flight instrument. For these postsource decay (PSD) experiments, ions were isolated in a ±10 to 15 Da window with an ion gate. PSD spectra were acquired by irradiating the sample with 38 to 50% increased laser power. The capability of this technique is demonstrated on protonated tryptic peptide ions at m/z 1929 and m/z 1940 derived from the 3:1 spore mixture of B. thuringiensis Kurstaki and B. globigii , respectively ( FIG. 4 and Table 1).
PSD spectra of both peptides (m/z 1929, m/z 1940) show extended fragmentation due to metastable decay. Peptide precursor and fragment ion mass values were exploited using the Mascot Sequence database query software available free on the internet. Typical search parameters used in this study are listed in Table 2.
TABLE 2
Database search parameters.
Database
NCBInr
Taxonomy
Bacteria Eubacteria
Missed cleavages
<1
Protein mass
Unrestricted
Fragment matches
b- and v-ion types
Peptide mass
+1 Da
Fragment ions
+1-1.5 Da
Based on fragment ion information from the protonated peptide ions at m/z 1929, spore protein 1 (MW 7227) from Geobacillus stearothermophilus was identified with a score of 215, while other candidates had scores lower than 45. Generally, only protein scores greater than 69 are considered as significant hits. As a result of interrogation based on fragments of the protonated peptide at m/z 1940, two α/(3-type spore proteins (MW 6805, 7290) were matched from B. anthracis A2012 and spore protein 2 (MW 6837) was matched from B. cereus , with scores between 194 and 195. Scores lower than 56 were shown for other candidates, reflecting insignificant matches. Since neither of the genomes of B. globigii and B. thuringiensis have been sequenced yet, these species could not be found in the database. Sequences for the small acid soluble proteins of these two species are also not present in the database at the present time. While less is known about B. globigii, B. thuringiensis, B. anthracis , and B. cereus represent closely related species (Helgason et al, Applied Environ Microbiol 66, 2627, 2000). Additional MS/MS studies of peptide fragments containing variant amino acids would be needed to clearly differentiate between these species. On the other hand, the example given demonstrates that Bacillus spore species can be differentiated in their mixtures based on a single in situ generated peptide of each species.
Experiment 3
The rapid identification of B. anthracis spores is a main focus of public interest. In this context, the differentiation between B. anthracis and B. thuringiensis spores, the latter a major contaminant in the troposphere, is crucial for a future implementation of the method described here in field studies. In this laboratory study, B. anthracis Sterne, a human non-pathogen (vaccine), serves as model organism for pathogenic B. anthracis strains. Genomes of the Sterne and Ames strains are assumed to be identical.
A 2:1 mixture of spores from B. anthracis Sterne and B. thuringiensis Kurstaki was prepared by placing 0.4 gl of each spore species on the MALDI sample plate. After on-slide spore lysis and direct digestion, peptide fragments were detected by MALDI-TOFMS analysis ( FIG. 5 ).
Although some peptide fragments with coincident mass-to-charge values are detected from the two spore species (see Table 1), the presence of B. anthracis Sterne spores is confirmed by PSD analysis of the protonated peptide at m/z 1519 ( FIG. 5 ).
Based on the information provided by peptide fragmentation, the database was searched using Mascot sequence query. The α/β-type spore protein from Bacillus anthracis A2012 was matched with a score of 93, while other candidates had scores lower than 47.
A compilation of PSD fragment ions of selected peptides generated in situ from whole bacterial spores and results of the corresponding database searches is presented in Table 3. The results in Tables 1 and 3 indicate that differentiation of spores of B. anthracis Sterne, B. subtilis, B. globigii, B. mycoides, B. cereus T and B. thuringiensis Kurstaki is feasible.
TABLE 3
Compilation of PSD fragment ions of some tryptic peptides generated in
situ from Bacillus sores and database search results. Protein
scores greater than 69 are considered significant.
[M +
Fragment ions
H] +
(average mass
Database search result
1519
1307, 1245, 1220, 984, 906,
gi|121402693, Mass: 6810, Total
(BA)
871, 778, 743, 650, 537,
score: 93, Small, acid-soluble spore
485, 300
proteins, α/β-type SASP from Bacillus
anthracis str. A2012.
1881
1639, 1526, 1455, 1368,
gi|16078040, Mass: 6980, Total
(BS)
1238, 1091, 1034, 935, 848,
score: 191, Small acid-soluble spore
821, 708, 580, 514, 464,
protein, α/β-type SASP from Bacillus
428, 421, 364, 356, 262,
subtilis .
243, 175
gi|116080009, Mass: 7071, Total
score: 191, Small acid-soluble spore
protein, α/β-type SASP from Bacillus
subtilis .
1929
1781, 1653, 1539, 1468,
gi|134224, Mass: 7227, Total score:
(BG)
1381, 1252, 1208, 1105,
215, Small, acid-soluble spore
1048, 949, 932, 835, 721,
protein, SASP 1 from Geobacillus
677, 593, 548, 464, 390,
stearothermo-chilus .
363, 277, 262, 175
1940
1776, 1648, 1535, 1463,
gi|21402693, Mass: 6810, Total score:
(BC,
1335, 1206, 1165, 1059,
195, Small, acid-soluble spore
BT)
1039, 1002, 939, 903, 775,
proteins, α/β-type from Bacillus
735, 662, 605, 534, 477,
anthracis str: A2012.
418, 406, 293, 175
gi|134231, Mass: 6842, Total score:
195, Small, acid-soluble spore
proteins 2 from Bacillus cereus .
gi|21401004, Mass: 7294, Total
score: 194, Small, acid-soluble spore
proteins, α/β-type from Bacillus
anthracis str A2012.
2785
2656, 2544, 2414, 2287,
gi|134246, Mass: 9020, Total score:
(BG)
2200, 2129, 2075, 1999,
210, Small, acid-soluble spore
1872, 1815, 1687, 1382,
proteins, γ-type from Geobacillus
1253, 1105, 1034, 947,
stearothermophilus .
818, 717, 602
2842
2600, 2473, 2344, 2257,
gi|16077932, Mass: 9268, Total
(BS)
2186, 2129, 1873, 1815,
score: 218, small acid-soluble spore
1687, 1540, 1483, 1382,
protein, γ-type from Bacillus subtilis .
1253, 1106, 1035, 819,
717, 602
With this approach, species-specific information is gained from various Bacillus spores and their mixtures. A predictable subset of proteins is selectively solubilized for the analysis. No isolation or fractionation of proteins from spore debris is needed. With both on-slide spore lysis and in situ digestion, equipment, time-consumption and sample amount are greatly reduced compared to using traditional protocols. The method is compatible with all MALDI-MS and MALDI MS/MS instruments, e.g., MALDI quadrupole TOF, MALDI-TOF/TOF, MALDI ion trap, MALDI ion trap-TOF, and MALDI-FTICR. It can be implemented with either post source decay or collision induced decomposition. Hence, the method can be widely employed.
Experiment 4
Vegetative cells of B. subtilis strain EMG 168, B. cereus strain T, B. globigii strain 9372, B. thuringiensis subs. Kurstaki strain HD-1 (ATCC 33679), B. sphaericus strain and B. anthracis Sterne, a non-pathogenic strain widely used as a vaccine for animals and lifestock, were suspended in a 1:1 mixture of MeOH and 25 mM ammonium bicarbonate buffer resulting in a final concentration of 2.5 mg of cells per milliliter. Aliquots of 0.8 μl of cell suspensions were directly placed on the MALDI plate, and bacterial samples were allowed to air dry (˜2.5 min). Subsequently, 1 μl of immobilized trypsin in 25 mM ammonium bicarbonate buffer (pH≈7.5) was deposited on each sample for in situ proteolytic digestion of the protein subset solubilized from the cells.
The MALDI plate was covered with a humidification chamber (100% relative humidity) at room temperature to prevent sample drying. Cleavage reactions were stopped by adding 0.1% TFA for peptide analysis by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry with α-cyano-4-hydroxycinnammic acid as MALDI matrix.
Using these conditions, extended enzymatic proteolysis of bacterial proteins were observed within 5 to 20 min providing tryptic peptides with ion signal intensities adequate for post-source decay (PSD) analysis with a curfed-field reflectron instrument (Kratos Analytical AXIMA-CFR supplied by Shimadzu Biotech, Manchester, U.K.).
MALDI MS and PSD spectra of high quality were acquired on the crude digests with no need of any further sample processing. Partial sequence information obtained from bacterial peptides by PSD was used for database searches in the NCBInr database taxonomically restricted to bacteria (eubacteria) via Mascot Sequence Query. Search parameters were usually set as follows: enzyme, trypsin; missed cleavages, 0; protein mass, unrestricted; product ion matches, b- and y-type ions; peptide ion mass tolerance, ±1.0 Da, product ion mass tolerance: ±1.5 Da.
The wild-type species Bacillus subtilis 168 was studied as a genetically amenable, nonpathogenic model system to elaborate on the potential of microsequencing by PSD combined with database searches for the rapid identification of bacteria. The MALDI spectra of the tryptic digests generated on probe from vegetative cells of B. subtilis 168 by enzymatic proteolysis for 5 and 20 min are shown in FIG. 7 . Peptide ions suitable for PSD analysis could be generated by tryptic digestion for 5 min. Formation of additional protonated peptides was observed by extending the digestion time to, e.g. 20 min, and well resolved peptide ion signals were found in the mass range of 1000 to 3100 Da. As digestion time was extended from 20 to 45 min, no significant change of the extend of proteolysis could be observed in the mass spectra.
To determine the identity of protein precursors, and, accordingly, their bacterial sources, distinct peptide ions were isolated with an ion gate set to a ±10 to 15-Da window, and PSD analysis of selected parent ions was performed by increasing the laser power by 40 to 50%. For most of the tryptic peptide ions from B. subtilis 168 extended metastable decay was observed in the field-free region, and PSD spectra could be obtained as a sum of about 150 laser shots.
Fragmentation spectra of ions of 2606.3 Da and 1923.5 Da are shown to demonstrate the high extend of sequence-specific information achievable by MALDI-PSD analysis ( FIG. 8 (a and b)), and product ions observed match b- and y-type ions. The latter referred to Y″-type ions according to the nomenclature introduced by Roepstorff and Fohlmann Since peptides with basic residues (Arg and Lys) on the C-terminal side are generated by protein cleavage with trypsin, formation of y-type ions is strongly favored, and cleavage of amino bonds containing glutamic acid and aspartic acid resulted in y-type ions with high abundances as reported before.
Uninterpreted PSD, and product ions were used with signal intensities at least 3% above the noise level were generically included in database searches with Mascot Sequence Query, making this identification process automatable.
Sequence information achieved from protonated peptides of 2606.3 Da and 1923.5 Da resulted in the identification of the flagellin and the cold-shock protein D (Csp-D) with Mascot scores up to 232, and B. subtilis 168 was retrieved from public databases as bacterial source for both proteins. The latter protein has been previously identified in a tryptic digest from a cellular extract of B. subtilis 168 via MALDI-PSD analysis. The identity of the flagellin protein could be further confirmed by partial sequencing of the protonated peptide of 2993.3 Da, and the detection of 4 additional tryptic peptides matching peptides from theoretical tryptic digests of the flagellin protein in mass as indicated in FIG. 7 .
The capability of this approach to provide complete cleavage products of the 32.6 kDa flagellin protein in B. subtilis 168 by on probe tryptic digestion in 10 to 20 min is particularly appealing, since the genes encoding such proteins have been already successfully targeted as biomarkers in detection, population genetics, and epidemiological analysis. Since the flagellin protein exists in as many as 20.000 copies composing the filament of the bacterial flagellum, it represents a naturally amplified biomarker suitable to detect bacterial species at potentially low concentrations. The majority of eubacterial flagellin proteins comprise about 500 amino acids with highly conserved N- and C-terminal regions, and a central domain that can vary considerably in both amino acid sequence and size (Joys, 1988; Wilson&Beveridge, 1993).
The combination of considerable intra-species differences in amino acid sequence and the quantity of sequence data available makes flagellar variation a biomarker with widespread potential uses for the specific detection and identification of species or strains of motile bacteria.
Additional PSD analysis of protonated tryptic peptides of 1923.5, 1878.9, and 2806.9 Da resulted in the identification of major cold-shock protein (Csps) listed for B. subtiltis 168 in public databases. Since Csps in B. subtilis exhibit extended sequence homologies, only the CspD of 7303.1 Da could be specifically identified in the this work.
In general, Csps constitute a widespread and highly conserved protein family in bacteria, and multiple copies of Csps are often present (10, 25). B. subtilis contains three csp genes, and CspB, CspC and CspD comprise one of the highest accumulating protein group of B. subtilis after a temperature downshift (Graumann et al., 1996). It is proposed that these proteins play important roles in the adaptation of cells to low-temperature conditions (Graumann & Marahiel, 1999) by, e.g., keeping critical mRNAs accessible for the ribosomes at low-temperatures (Graumann et al., 1997; Schindler et al., 1999). Nonetheless, Csps in bacterial cells are also present at 37° C. (6, 9), and the presence of at least one Csp is necessary to maintain viability of B. subtilis at low and optimal growth temperatures, while depletion of Csps leads to compromised and deregulated protein synthesis (6).
To exclude accidentally induced overexpression of Csps in B. subtilis 168 by, for example, the storage of vegetative cells at −80° C. before use, a control experiment was performed, and cells not exposed to any temperature downshifts were prepared. For this purpose, cells were harvested, purified by repeated salt washes, and directly digested on probe with trypsin, yet, no significant change in mass and relative abundance of peptide ions could be observed in the MALDI spectra obtained (not shown) compared to the spectrum shown in FIG. 7 b . Molecular masses of cold-shock proteins retrieved from searches in the NCBInr database range from 4977 Da to 7405 Da, and extended sequence homologies are exhibited within these proteins. In addition, the non-specific DNA-binding protein HBsu in B. subtils 168 as indicated in the MALDI spectrum shown in FIG. 7 was identified. Sequences of the non-specific DNA-binding proteins with molecular masses of 9897.38 Da in B. subtilis 168 and of 9884.29 Da in B. globigii differ only in a single amino acid, and in silico digests with trypsin reveal only one unique peptide for these proteins each with a mass below 450 Da.
|
Organisms such as bacterial spores are analyzed and/or characterized based on based on peptide fragments of a set of selectively solublizede proteins. Libraries of protein and gene sequences may be utilized for comparison to and identification of proteins and unknown organisms.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention generally relates to a drum washing machine. And more particularly, to improving washing performance by increasing the vigor with which water is circulated within the spin basket.
(2) Description of the Prior Art
A conventional drum washing machine is an electronic appliance that washes clothes using suds created during the rotation of its drum-shaped spin basket. As shown in FIG. 6, a conventional spin basket 1 has a plurality of lifters 2 protruded inward on its side wall so that the elevation of water and laundry contained in the spin basket 1 is more efficiently accomplished. In other words, the water and laundry in the spin basket 1 rise up the spin basket inner wall to a predetermined point, and then fall down from that point in such a manner that the laundry is washed by the suds produced by this rising and falling action. The lifters 2 serve to draw up the water and laundry so as to raise and drop the water and laundry and produce a large amount of suds.
With such a conventional drum washing machine, however, there is a limitation to the enhancement of the washing performance, because the laundry and water drop by interaction between centrifugal force, produced by the rotation of the spin basket 1, and the lifters 2 provided at the inside of the spin basket 1. That is, the laundry and water are lifted by the lifters 2, and the water that has once gone up to a predetermined point (the position where the gravitation force is larger than the centrifugal force acting thereon) must fall down, while the laundry, being a solid, is lifted to a higher point. Thus, the water does not rise high enough, and the amount of lifted water is not enough to generate the amount of suds necessary for washing, thereby lowering the washing efficiency.
SUMMARY OF THE INVENTION
It is an objective of the present invention to provide a drum washing machine which can provide improved washing performance by lifting a greater amount of water for washing to a higher point than and then allowing the water to fall down from that point.
In order to obtain the aforementioned objectives of the present invention, there is disclosed a drum washing machine including: a tub; a spin basket, having a plurality of holes so as to allow water to freely flow between the spin basket and the tub, formed in the tub to be rotatable about a horizontally-supported shaft; lifters protruding to the inside of the spin basket to make the water and laundry rise and drop; and a plurality of water-elevating members for holding the water therein during the rotation of the spin basket and allowing the water to drop down only after it has reached a predetermined point.
The lifters are formed by compressing the spin basket's side surface to its inside in a "V" shape, having a plurality of holes for allowing the spin basket to communicate with the tub. The water-elevating members, each having a body with a plurality of apertures, are provided to cover each lifter's concave backside so as to form a space therebetween, into which the water flows.
The apertures are arranged lengthwise in the body. First guides are provided at one side of each of half the apertures with their free ends extending on an upward angle to the other side thereof. Second guides are provided at one side of each of the second half of the apertures with their free ends extending on an upward angle in the opposite direction as the first half of the apertures.
The coupling portions are formed on both ends of the body so as to be attached to the front and rear panels of the spin basket, and the coupling portions and front and rear panels of the spin basket are joined to each other by a fastening member, thus fixing the lifter supporting members onto the outside of each lifter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the interior construction of a drum washing machine in accordance with the present invention;
FIG. 2 is a sectional view of a spin basket of FIG. 1;
FIG. 3 is an exploded perspective view of the spin basket with a lifter and an inventive water-elevating member;
FIG. 4 is a sectional view as taken along line IV--IV of FIG. 3;
FIG. 5 is an enlarged view of "A" of the encircled segment FIG. 2; and
FIG. 6 is a sectional view of a spin basket for a conventional drum washing machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention will be now described in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view showing the overall construction of a drum washing machine in accordance with the present invention.
As shown in FIG. 1, the drum washing machine includes a housing 10, a tub 20 suspended in the housing 10, a spin basket 30 rotatably installed within the tub 20, and an electric motor 50, which rotates the spin basket 30, mounted below the tub 20. The tub 20, which is of cylindrical shape, is installed parallel to the ground in the housing 10, and buffer springs 11 are provided between the housing 10 and the top of the tub 20 to suspend the tub 20 within the housing 10. Under the tub 20 are formed a pair of shock absorbing arms 12. These shock absorbing arms 12 are fixed onto the bottom of the housing 10.
Openings 10a, 20a and 30a are formed on the front of the housing 10, a predetermined spot on the tub 20 corresponding to the front of the housing 10, and a corresponding spot on the spin basket 30, respectively, so that laundry can be put into or taken out of the spin basket 30 therethrough. A door (not illustrated) is provided to open and close the openings 10a, 20a and 30a.
The spin basket 30 consists of a cylindrically-shaped member or side panel 31, and front and rear end panels 32 and 33 respectively joined to the front and back of the side panel 31. The front and rear panels 32 and 33 are firmly fastened to each other by a coupling member. A bolt 40 is used as this coupling member in this preferred embodiment. A plurality of holes 31a are uniformly distributed in the side panel 31 so that water can flow freely between the spin basket 30 and the tub 20.
One end of a shaft 51 is connected to the rear panel 33 of the spin basket 30 by means of a flange 52, and the other end extends to the rear of the tub 20. A belt 57 is provided between a first pulley 55, which is connected to the motor 50, and a second pulley 56, which is connected to the shaft 51 so that the rotating force of the motor 50 is transmitted to the spin basket 30 by way of the shaft 51. The shaft 51 is horizontally supported by a pair of bearings 53 that are placed in a bearing housing 54 mounted on the tub 20.
As shown in FIG. 2, a plurality of lifters 31b are formed protruding from the inner side panel 31 of the spin basket 30, and serves to efficiently lift the laundry and water during the rotation of the spin basket 30. These lifters 33b are three in number, and are spaced 120° from each other. The lifters 31b comprise a wall formed by bending a part of the side panel 31 towards the spin basket center, and extend downward along the spin basket inner surface, the wall thus being V-shaped and formed by first and second wall sections 31b' and 31b" which converge generally toward a center of the spin basket.
The spin basket 30 includes water-elevating members 60 for improving washing efficiency by thoroughly mixing the laundry with the water that they had lifted in addition to the lifters 31b. Referring to FIGS. 3 and 4, the water-elevating members 60 are more fully described as follows.
Each of the water-elevating members 60 includes a cover body 61 that is provided to the outside of each lifter 31b, covering the concave back of the lifter 31b. This forms a space between the water-elevating member 60 and the lifter 31b, so that the water flowing into the spin basket 30, is raised to a predetermined point. The body 61 forms a rear wall of the space and has a plurality of apertures 61a used to allow the water to freely flow into the space. The apertures 61a are arranged lengthwise in two rows on the body 61. First and second guides 63 and 64 are provided to the outside of the apertures 61a, thus allowing the water to efficiently flow between the lifter 31b and the body 61 during the rotation of the spin basket 30. The first guides 63 for the respective apertures 61a on the left of the body 61, are provided on the right side of each of the apertures 61a. Each first guide 63 is angled away from the inside of the spin basket 30, and as the spin basket 30 rotates counterclockwise, it makes the inflow of water efficient. The second guides 64 for the apertures 61a on the right of the body 61, are extending from the left side of each aperture 61a and angled away from the inside of the spin basket 60, thereby making the inflow of water efficient during the clockwise rotation of the spin basket 30.
The water-elevating member 60 is securely fastened to the front and rear panels 32 and 33 by the bolt 40 used to join the front and rear panels 32 and 33 together. Coupling portions 62 of the body 61 are joined to the front and rear panels 32 and 33 by the bolt 40. The bolt head 41 of the bolt 40 is positioned at the rear, and its shank 42 extends passing through the rear panel 33, the coupling portions 62, and the front panel 32 to thereby fasten onto a nut 43. Each coupling portion 62 is of a proper thickness for firmness.
As shown in FIGS. 3 and 5, both of wall sections 31b' and 31b" of each of lifters 31b have a plurality of holes 31c for allowing the spin basket 30 to communicate with the tub 20 so that the water lifted by the water-elevating members 60 drops into the spin basket 30. The holes 31c are formed on both side surfaces of the lifter 31b and the corner portion between those two side surfaces, thus being arranged in three rows. It is preferable that twenty five holes 31c are formed in each row, and the number of the holes 31c and the length of extension of each guide 63 and 64 may be manipulated to allow the water to drop from the highest possible point.
The following description concerns the operation of the drum washing machine and its advantages.
Once the motor 50 goes into action to rotate the spin basket 30 and the laundry and water contained therein forward and reverse, the lifters 31b carry the laundry and water up to a predetermined point within the spin basket 30 by centrifugal force wherefrom they then fall down. Suds, generated thereby, remove soil from the laundry. The water-elevating members 60, provided to the outside of each lifter 31b, lift the water to the outside of the spin basket 30 and then drop it to the inside of the spin basket 30 through the holes 31c, thereby enhancing washing efficiency.
More specifically, when the spin basket 30 rotates clockwise, the water flows into the apertures 61a of the body 61 by the angled guides 64, and then drops into the spin basket 30 through the holes 31c. If the spin basket 30 rotates counterclockwise, the water flows into the apertures 61a by the guides 63 that are angled in the opposite direction as the aforementioned guiders 64, and then falls down to the inside of the spin basket 30 via the holes 31c. By delaying the falling of the water so that the water falls down from a higher predetermined point forces the removal of soil from the laundry, thus increasing washing efficiency. Should the adjustment be properly made of the shape of each of the holes 31c and guides 63 and 64 so as to make the water drop from the highest point of the spin basket 30, the washing efficiency would be even more enhanced.
As described above, in the drum washing machine of the present invention, the water falls out of the lifers down to the inside of the spin basket from the highest possible point, and the suds, produced by the flowing water, remove soil from the laundry. In addition, the water-elevating members are respectively provided to the outside of the lifters, thereby providing improved lifting performance.
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A drum washing machine includes a spin basket rotatable within a tub about a horizontal axis. Projecting radially inwardly from a cylindrical wall of the spin basket is a plurality of lifters which raise clothes and then let them fall. The lifters form internal spaces into which wash water can flow. That water is raised and then flows downwardly back onto the clothes to increase washing efficiency.
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